can: mcp25xxfd: add driver for Microchip MCP25xxFD SPI CAN
authorMarc Kleine-Budde <mkl@pengutronix.de>
Fri, 18 Sep 2020 17:25:33 +0000 (19:25 +0200)
committerMarc Kleine-Budde <mkl@pengutronix.de>
Mon, 21 Sep 2020 08:13:20 +0000 (10:13 +0200)
This patch adds support for the Microchip MCP25xxFD SPI CAN controller family.

Tested-by: Kurt Van Dijck <dev.kurt@vandijck-laurijssen.be>
Tested-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Link: https://lore.kernel.org/r/20200918172536.2074504-4-mkl@pengutronix.de
drivers/net/can/spi/mcp25xxfd/Makefile
drivers/net/can/spi/mcp25xxfd/mcp25xxfd-core.c [new file with mode: 0644]

index 9dadf00..4e17f59 100644 (file)
@@ -3,5 +3,6 @@
 obj-$(CONFIG_CAN_MCP25XXFD) += mcp25xxfd.o
 
 mcp25xxfd-objs :=
+mcp25xxfd-objs += mcp25xxfd-core.o
 mcp25xxfd-objs += mcp25xxfd-crc16.o
 mcp25xxfd-objs += mcp25xxfd-regmap.o
diff --git a/drivers/net/can/spi/mcp25xxfd/mcp25xxfd-core.c b/drivers/net/can/spi/mcp25xxfd/mcp25xxfd-core.c
new file mode 100644 (file)
index 0000000..10e4b6d
--- /dev/null
@@ -0,0 +1,2907 @@
+// SPDX-License-Identifier: GPL-2.0
+//
+// mcp25xxfd - Microchip MCP25xxFD Family CAN controller driver
+//
+// Copyright (c) 2019, 2020 Pengutronix,
+//                          Marc Kleine-Budde <kernel@pengutronix.de>
+//
+// Based on:
+//
+// CAN bus driver for Microchip 25XXFD CAN Controller with SPI Interface
+//
+// Copyright (c) 2019 Martin Sperl <kernel@martin.sperl.org>
+//
+
+#include <linux/bitfield.h>
+#include <linux/clk.h>
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/netdevice.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/pm_runtime.h>
+
+#include <asm/unaligned.h>
+
+#include "mcp25xxfd.h"
+
+#define DEVICE_NAME "mcp25xxfd"
+
+static const struct mcp25xxfd_devtype_data mcp25xxfd_devtype_data_mcp2517fd = {
+       .quirks = MCP25XXFD_QUIRK_MAB_NO_WARN | MCP25XXFD_QUIRK_CRC_REG |
+               MCP25XXFD_QUIRK_CRC_RX | MCP25XXFD_QUIRK_CRC_TX |
+               MCP25XXFD_QUIRK_ECC,
+       .model = MCP25XXFD_MODEL_MCP2517FD,
+};
+
+static const struct mcp25xxfd_devtype_data mcp25xxfd_devtype_data_mcp2518fd = {
+       .quirks = MCP25XXFD_QUIRK_CRC_REG | MCP25XXFD_QUIRK_CRC_RX |
+               MCP25XXFD_QUIRK_CRC_TX | MCP25XXFD_QUIRK_ECC,
+       .model = MCP25XXFD_MODEL_MCP2518FD,
+};
+
+/* Autodetect model, start with CRC enabled. */
+static const struct mcp25xxfd_devtype_data mcp25xxfd_devtype_data_mcp25xxfd = {
+       .quirks = MCP25XXFD_QUIRK_CRC_REG | MCP25XXFD_QUIRK_CRC_RX |
+               MCP25XXFD_QUIRK_CRC_TX | MCP25XXFD_QUIRK_ECC,
+       .model = MCP25XXFD_MODEL_MCP25XXFD,
+};
+
+static const struct can_bittiming_const mcp25xxfd_bittiming_const = {
+       .name = DEVICE_NAME,
+       .tseg1_min = 2,
+       .tseg1_max = 256,
+       .tseg2_min = 1,
+       .tseg2_max = 128,
+       .sjw_max = 128,
+       .brp_min = 1,
+       .brp_max = 256,
+       .brp_inc = 1,
+};
+
+static const struct can_bittiming_const mcp25xxfd_data_bittiming_const = {
+       .name = DEVICE_NAME,
+       .tseg1_min = 1,
+       .tseg1_max = 32,
+       .tseg2_min = 1,
+       .tseg2_max = 16,
+       .sjw_max = 16,
+       .brp_min = 1,
+       .brp_max = 256,
+       .brp_inc = 1,
+};
+
+static const char *__mcp25xxfd_get_model_str(enum mcp25xxfd_model model)
+{
+       switch (model) {
+       case MCP25XXFD_MODEL_MCP2517FD:
+               return "MCP2517FD"; break;
+       case MCP25XXFD_MODEL_MCP2518FD:
+               return "MCP2518FD"; break;
+       case MCP25XXFD_MODEL_MCP25XXFD:
+               return "MCP25xxFD"; break;
+       }
+
+       return "<unknown>";
+}
+
+static inline const char *
+mcp25xxfd_get_model_str(const struct mcp25xxfd_priv *priv)
+{
+       return __mcp25xxfd_get_model_str(priv->devtype_data.model);
+}
+
+static const char *mcp25xxfd_get_mode_str(const u8 mode)
+{
+       switch (mode) {
+       case MCP25XXFD_REG_CON_MODE_MIXED:
+               return "Mixed (CAN FD/CAN 2.0)"; break;
+       case MCP25XXFD_REG_CON_MODE_SLEEP:
+               return "Sleep"; break;
+       case MCP25XXFD_REG_CON_MODE_INT_LOOPBACK:
+               return "Internal Loopback"; break;
+       case MCP25XXFD_REG_CON_MODE_LISTENONLY:
+               return "Listen Only"; break;
+       case MCP25XXFD_REG_CON_MODE_CONFIG:
+               return "Configuration"; break;
+       case MCP25XXFD_REG_CON_MODE_EXT_LOOPBACK:
+               return "External Loopback"; break;
+       case MCP25XXFD_REG_CON_MODE_CAN2_0:
+               return "CAN 2.0"; break;
+       case MCP25XXFD_REG_CON_MODE_RESTRICTED:
+               return "Restricted Operation"; break;
+       }
+
+       return "<unknown>";
+}
+
+static inline int mcp25xxfd_vdd_enable(const struct mcp25xxfd_priv *priv)
+{
+       if (!priv->reg_vdd)
+               return 0;
+
+       return regulator_enable(priv->reg_vdd);
+}
+
+static inline int mcp25xxfd_vdd_disable(const struct mcp25xxfd_priv *priv)
+{
+       if (!priv->reg_vdd)
+               return 0;
+
+       return regulator_disable(priv->reg_vdd);
+}
+
+static inline int
+mcp25xxfd_transceiver_enable(const struct mcp25xxfd_priv *priv)
+{
+       if (!priv->reg_xceiver)
+               return 0;
+
+       return regulator_enable(priv->reg_xceiver);
+}
+
+static inline int
+mcp25xxfd_transceiver_disable(const struct mcp25xxfd_priv *priv)
+{
+       if (!priv->reg_xceiver)
+               return 0;
+
+       return regulator_disable(priv->reg_xceiver);
+}
+
+static int mcp25xxfd_clks_and_vdd_enable(const struct mcp25xxfd_priv *priv)
+{
+       int err;
+
+       err = clk_prepare_enable(priv->clk);
+       if (err)
+               return err;
+
+       err = mcp25xxfd_vdd_enable(priv);
+       if (err)
+               clk_disable_unprepare(priv->clk);
+
+       /* Wait for oscillator stabilisation time after power up */
+       usleep_range(MCP25XXFD_OSC_STAB_SLEEP_US,
+                    2 * MCP25XXFD_OSC_STAB_SLEEP_US);
+
+       return err;
+}
+
+static int mcp25xxfd_clks_and_vdd_disable(const struct mcp25xxfd_priv *priv)
+{
+       int err;
+
+       err = mcp25xxfd_vdd_disable(priv);
+       if (err)
+               return err;
+
+       clk_disable_unprepare(priv->clk);
+
+       return 0;
+}
+
+static inline u8
+mcp25xxfd_cmd_prepare_write_reg(const struct mcp25xxfd_priv *priv,
+                               union mcp25xxfd_write_reg_buf *write_reg_buf,
+                               const u16 reg, const u32 mask, const u32 val)
+{
+       u8 first_byte, last_byte, len;
+       u8 *data;
+       __le32 val_le32;
+
+       first_byte = mcp25xxfd_first_byte_set(mask);
+       last_byte = mcp25xxfd_last_byte_set(mask);
+       len = last_byte - first_byte + 1;
+
+       data = mcp25xxfd_spi_cmd_write(priv, write_reg_buf, reg + first_byte);
+       val_le32 = cpu_to_le32(val >> BITS_PER_BYTE * first_byte);
+       memcpy(data, &val_le32, len);
+
+       if (priv->devtype_data.quirks & MCP25XXFD_QUIRK_CRC_REG) {
+               u16 crc;
+
+               mcp25xxfd_spi_cmd_crc_set_len_in_reg(&write_reg_buf->crc.cmd,
+                                                    len);
+               /* CRC */
+               len += sizeof(write_reg_buf->crc.cmd);
+               crc = mcp25xxfd_crc16_compute(&write_reg_buf->crc, len);
+               put_unaligned_be16(crc, (void *)write_reg_buf + len);
+
+               /* Total length */
+               len += sizeof(write_reg_buf->crc.crc);
+       } else {
+               len += sizeof(write_reg_buf->nocrc.cmd);
+       }
+
+       return len;
+}
+
+static inline int
+mcp25xxfd_tef_tail_get_from_chip(const struct mcp25xxfd_priv *priv,
+                                u8 *tef_tail)
+{
+       u32 tef_ua;
+       int err;
+
+       err = regmap_read(priv->map_reg, MCP25XXFD_REG_TEFUA, &tef_ua);
+       if (err)
+               return err;
+
+       *tef_tail = tef_ua / sizeof(struct mcp25xxfd_hw_tef_obj);
+
+       return 0;
+}
+
+static inline int
+mcp25xxfd_tx_tail_get_from_chip(const struct mcp25xxfd_priv *priv,
+                               u8 *tx_tail)
+{
+       u32 fifo_sta;
+       int err;
+
+       err = regmap_read(priv->map_reg,
+                         MCP25XXFD_REG_FIFOSTA(MCP25XXFD_TX_FIFO),
+                         &fifo_sta);
+       if (err)
+               return err;
+
+       *tx_tail = FIELD_GET(MCP25XXFD_REG_FIFOSTA_FIFOCI_MASK, fifo_sta);
+
+       return 0;
+}
+
+static inline int
+mcp25xxfd_rx_head_get_from_chip(const struct mcp25xxfd_priv *priv,
+                               const struct mcp25xxfd_rx_ring *ring,
+                               u8 *rx_head)
+{
+       u32 fifo_sta;
+       int err;
+
+       err = regmap_read(priv->map_reg, MCP25XXFD_REG_FIFOSTA(ring->fifo_nr),
+                         &fifo_sta);
+       if (err)
+               return err;
+
+       *rx_head = FIELD_GET(MCP25XXFD_REG_FIFOSTA_FIFOCI_MASK, fifo_sta);
+
+       return 0;
+}
+
+static inline int
+mcp25xxfd_rx_tail_get_from_chip(const struct mcp25xxfd_priv *priv,
+                               const struct mcp25xxfd_rx_ring *ring,
+                               u8 *rx_tail)
+{
+       u32 fifo_ua;
+       int err;
+
+       err = regmap_read(priv->map_reg, MCP25XXFD_REG_FIFOUA(ring->fifo_nr),
+                         &fifo_ua);
+       if (err)
+               return err;
+
+       fifo_ua -= ring->base - MCP25XXFD_RAM_START;
+       *rx_tail = fifo_ua / ring->obj_size;
+
+       return 0;
+}
+
+static void
+mcp25xxfd_tx_ring_init_tx_obj(const struct mcp25xxfd_priv *priv,
+                             const struct mcp25xxfd_tx_ring *ring,
+                             struct mcp25xxfd_tx_obj *tx_obj,
+                             const u8 rts_buf_len,
+                             const u8 n)
+{
+       struct spi_transfer *xfer;
+       u16 addr;
+
+       /* FIFO load */
+       addr = mcp25xxfd_get_tx_obj_addr(ring, n);
+       if (priv->devtype_data.quirks & MCP25XXFD_QUIRK_CRC_TX)
+               mcp25xxfd_spi_cmd_write_crc_set_addr(&tx_obj->buf.crc.cmd,
+                                                    addr);
+       else
+               mcp25xxfd_spi_cmd_write_nocrc(&tx_obj->buf.nocrc.cmd,
+                                             addr);
+
+       xfer = &tx_obj->xfer[0];
+       xfer->tx_buf = &tx_obj->buf;
+       xfer->len = 0;  /* actual len is assigned on the fly */
+       xfer->cs_change = 1;
+       xfer->cs_change_delay.value = 0;
+       xfer->cs_change_delay.unit = SPI_DELAY_UNIT_NSECS;
+
+       /* FIFO request to send */
+       xfer = &tx_obj->xfer[1];
+       xfer->tx_buf = &ring->rts_buf;
+       xfer->len = rts_buf_len;
+
+       /* SPI message */
+       spi_message_init_with_transfers(&tx_obj->msg, tx_obj->xfer,
+                                       ARRAY_SIZE(tx_obj->xfer));
+}
+
+static void mcp25xxfd_ring_init(struct mcp25xxfd_priv *priv)
+{
+       struct mcp25xxfd_tx_ring *tx_ring;
+       struct mcp25xxfd_rx_ring *rx_ring, *prev_rx_ring = NULL;
+       struct mcp25xxfd_tx_obj *tx_obj;
+       u32 val;
+       u16 addr;
+       u8 len;
+       int i;
+
+       /* TEF */
+       priv->tef.head = 0;
+       priv->tef.tail = 0;
+
+       /* TX */
+       tx_ring = priv->tx;
+       tx_ring->head = 0;
+       tx_ring->tail = 0;
+       tx_ring->base = mcp25xxfd_get_tef_obj_addr(tx_ring->obj_num);
+
+       /* FIFO request to send */
+       addr = MCP25XXFD_REG_FIFOCON(MCP25XXFD_TX_FIFO);
+       val = MCP25XXFD_REG_FIFOCON_TXREQ | MCP25XXFD_REG_FIFOCON_UINC;
+       len = mcp25xxfd_cmd_prepare_write_reg(priv, &tx_ring->rts_buf,
+                                             addr, val, val);
+
+       mcp25xxfd_for_each_tx_obj(tx_ring, tx_obj, i)
+               mcp25xxfd_tx_ring_init_tx_obj(priv, tx_ring, tx_obj, len, i);
+
+       /* RX */
+       mcp25xxfd_for_each_rx_ring(priv, rx_ring, i) {
+               rx_ring->head = 0;
+               rx_ring->tail = 0;
+               rx_ring->nr = i;
+               rx_ring->fifo_nr = MCP25XXFD_RX_FIFO(i);
+
+               if (!prev_rx_ring)
+                       rx_ring->base =
+                               mcp25xxfd_get_tx_obj_addr(tx_ring,
+                                                         tx_ring->obj_num);
+               else
+                       rx_ring->base = prev_rx_ring->base +
+                               prev_rx_ring->obj_size *
+                               prev_rx_ring->obj_num;
+
+               prev_rx_ring = rx_ring;
+       }
+}
+
+static void mcp25xxfd_ring_free(struct mcp25xxfd_priv *priv)
+{
+       int i;
+
+       for (i = ARRAY_SIZE(priv->rx) - 1; i > 0; i--) {
+               kfree(priv->rx[i]);
+               priv->rx[i] = NULL;
+       }
+}
+
+static int mcp25xxfd_ring_alloc(struct mcp25xxfd_priv *priv)
+{
+       struct mcp25xxfd_tx_ring *tx_ring;
+       struct mcp25xxfd_rx_ring *rx_ring;
+       int tef_obj_size, tx_obj_size, rx_obj_size;
+       int tx_obj_num;
+       int ram_free, i;
+
+       tef_obj_size = sizeof(struct mcp25xxfd_hw_tef_obj);
+       if (priv->can.ctrlmode & CAN_CTRLMODE_FD) {
+               tx_obj_num = MCP25XXFD_TX_OBJ_NUM_CANFD;
+               tx_obj_size = sizeof(struct mcp25xxfd_hw_tx_obj_canfd);
+               rx_obj_size = sizeof(struct mcp25xxfd_hw_rx_obj_canfd);
+       } else {
+               tx_obj_num = MCP25XXFD_TX_OBJ_NUM_CAN;
+               tx_obj_size = sizeof(struct mcp25xxfd_hw_tx_obj_can);
+               rx_obj_size = sizeof(struct mcp25xxfd_hw_rx_obj_can);
+       }
+
+       tx_ring = priv->tx;
+       tx_ring->obj_num = tx_obj_num;
+       tx_ring->obj_size = tx_obj_size;
+
+       ram_free = MCP25XXFD_RAM_SIZE - tx_obj_num *
+               (tef_obj_size + tx_obj_size);
+
+       for (i = 0;
+            i < ARRAY_SIZE(priv->rx) && ram_free >= rx_obj_size;
+            i++) {
+               int rx_obj_num;
+
+               rx_obj_num = ram_free / rx_obj_size;
+               rx_obj_num = min(1 << (fls(rx_obj_num) - 1), 32);
+
+               rx_ring = kzalloc(sizeof(*rx_ring) + rx_obj_size * rx_obj_num,
+                                 GFP_KERNEL);
+               if (!rx_ring) {
+                       mcp25xxfd_ring_free(priv);
+                       return -ENOMEM;
+               }
+               rx_ring->obj_num = rx_obj_num;
+               rx_ring->obj_size = rx_obj_size;
+               priv->rx[i] = rx_ring;
+
+               ram_free -= rx_ring->obj_num * rx_ring->obj_size;
+       }
+       priv->rx_ring_num = i;
+
+       netdev_dbg(priv->ndev,
+                  "FIFO setup: TEF: %d*%d bytes = %d bytes, TX: %d*%d bytes = %d bytes\n",
+                  tx_obj_num, tef_obj_size, tef_obj_size * tx_obj_num,
+                  tx_obj_num, tx_obj_size, tx_obj_size * tx_obj_num);
+
+       mcp25xxfd_for_each_rx_ring(priv, rx_ring, i) {
+               netdev_dbg(priv->ndev,
+                          "FIFO setup: RX-%d: %d*%d bytes = %d bytes\n",
+                          i, rx_ring->obj_num, rx_ring->obj_size,
+                          rx_ring->obj_size * rx_ring->obj_num);
+       }
+
+       netdev_dbg(priv->ndev,
+                  "FIFO setup: free: %d bytes\n",
+                  ram_free);
+
+       return 0;
+}
+
+static inline int
+mcp25xxfd_chip_get_mode(const struct mcp25xxfd_priv *priv, u8 *mode)
+{
+       u32 val;
+       int err;
+
+       err = regmap_read(priv->map_reg, MCP25XXFD_REG_CON, &val);
+       if (err)
+               return err;
+
+       *mode = FIELD_GET(MCP25XXFD_REG_CON_OPMOD_MASK, val);
+
+       return 0;
+}
+
+static int
+__mcp25xxfd_chip_set_mode(const struct mcp25xxfd_priv *priv,
+                         const u8 mode_req, bool nowait)
+{
+       u32 con, con_reqop;
+       int err;
+
+       con_reqop = FIELD_PREP(MCP25XXFD_REG_CON_REQOP_MASK, mode_req);
+       err = regmap_update_bits(priv->map_reg, MCP25XXFD_REG_CON,
+                                MCP25XXFD_REG_CON_REQOP_MASK, con_reqop);
+       if (err)
+               return err;
+
+       if (mode_req == MCP25XXFD_REG_CON_MODE_SLEEP || nowait)
+               return 0;
+
+       err = regmap_read_poll_timeout(priv->map_reg, MCP25XXFD_REG_CON, con,
+                                      FIELD_GET(MCP25XXFD_REG_CON_OPMOD_MASK,
+                                                con) == mode_req,
+                                      MCP25XXFD_POLL_SLEEP_US,
+                                      MCP25XXFD_POLL_TIMEOUT_US);
+       if (err) {
+               u8 mode = FIELD_GET(MCP25XXFD_REG_CON_OPMOD_MASK, con);
+
+               netdev_err(priv->ndev,
+                          "Controller failed to enter mode %s Mode (%u) and stays in %s Mode (%u).\n",
+                          mcp25xxfd_get_mode_str(mode_req), mode_req,
+                          mcp25xxfd_get_mode_str(mode), mode);
+               return err;
+       }
+
+       return 0;
+}
+
+static inline int
+mcp25xxfd_chip_set_mode(const struct mcp25xxfd_priv *priv,
+                       const u8 mode_req)
+{
+       return __mcp25xxfd_chip_set_mode(priv, mode_req, false);
+}
+
+static inline int
+mcp25xxfd_chip_set_mode_nowait(const struct mcp25xxfd_priv *priv,
+                              const u8 mode_req)
+{
+       return __mcp25xxfd_chip_set_mode(priv, mode_req, true);
+}
+
+static inline bool mcp25xxfd_osc_invalid(u32 reg)
+{
+       return reg == 0x0 || reg == 0xffffffff;
+}
+
+static int mcp25xxfd_chip_clock_enable(const struct mcp25xxfd_priv *priv)
+{
+       u32 osc, osc_reference, osc_mask;
+       int err;
+
+       /* Set Power On Defaults for "Clock Output Divisor" and remove
+        * "Oscillator Disable" bit.
+        */
+       osc = FIELD_PREP(MCP25XXFD_REG_OSC_CLKODIV_MASK,
+                        MCP25XXFD_REG_OSC_CLKODIV_10);
+       osc_reference = MCP25XXFD_REG_OSC_OSCRDY;
+       osc_mask = MCP25XXFD_REG_OSC_OSCRDY | MCP25XXFD_REG_OSC_PLLRDY;
+
+       /* Note:
+        *
+        * If the controller is in Sleep Mode the following write only
+        * removes the "Oscillator Disable" bit and powers it up. All
+        * other bits are unaffected.
+        */
+       err = regmap_write(priv->map_reg, MCP25XXFD_REG_OSC, osc);
+       if (err)
+               return err;
+
+       /* Wait for "Oscillator Ready" bit */
+       err = regmap_read_poll_timeout(priv->map_reg, MCP25XXFD_REG_OSC, osc,
+                                      (osc & osc_mask) == osc_reference,
+                                      MCP25XXFD_OSC_STAB_SLEEP_US,
+                                      MCP25XXFD_OSC_STAB_TIMEOUT_US);
+       if (mcp25xxfd_osc_invalid(osc)) {
+               netdev_err(priv->ndev,
+                          "Failed to detect %s (osc=0x%08x).\n",
+                          mcp25xxfd_get_model_str(priv), osc);
+               return -ENODEV;
+       } else if (err == -ETIMEDOUT) {
+               netdev_err(priv->ndev,
+                          "Timeout waiting for Oscillator Ready (osc=0x%08x, osc_reference=0x%08x)\n",
+                          osc, osc_reference);
+               return -ETIMEDOUT;
+       } else if (err) {
+               return err;
+       }
+
+       return 0;
+}
+
+static int mcp25xxfd_chip_softreset_do(const struct mcp25xxfd_priv *priv)
+{
+       const __be16 cmd = mcp25xxfd_cmd_reset();
+       int err;
+
+       /* The Set Mode and SPI Reset command only seems to works if
+        * the controller is not in Sleep Mode.
+        */
+       err = mcp25xxfd_chip_clock_enable(priv);
+       if (err)
+               return err;
+
+       err = mcp25xxfd_chip_set_mode(priv, MCP25XXFD_REG_CON_MODE_CONFIG);
+       if (err)
+               return err;
+
+       /* spi_write_then_read() works with non DMA-safe buffers */
+       return spi_write_then_read(priv->spi, &cmd, sizeof(cmd), NULL, 0);
+}
+
+static int mcp25xxfd_chip_softreset_check(const struct mcp25xxfd_priv *priv)
+{
+       u32 osc, osc_reference;
+       u8 mode;
+       int err;
+
+       err = mcp25xxfd_chip_get_mode(priv, &mode);
+       if (err)
+               return err;
+
+       if (mode != MCP25XXFD_REG_CON_MODE_CONFIG) {
+               netdev_info(priv->ndev,
+                           "Controller not in Config Mode after reset, but in %s Mode (%u).\n",
+                           mcp25xxfd_get_mode_str(mode), mode);
+               return -ETIMEDOUT;
+       }
+
+       osc_reference = MCP25XXFD_REG_OSC_OSCRDY |
+               FIELD_PREP(MCP25XXFD_REG_OSC_CLKODIV_MASK,
+                          MCP25XXFD_REG_OSC_CLKODIV_10);
+
+       /* check reset defaults of OSC reg */
+       err = regmap_read(priv->map_reg, MCP25XXFD_REG_OSC, &osc);
+       if (err)
+               return err;
+
+       if (osc != osc_reference) {
+               netdev_info(priv->ndev,
+                           "Controller failed to reset. osc=0x%08x, reference value=0x%08x\n",
+                           osc, osc_reference);
+               return -ETIMEDOUT;
+       }
+
+       return 0;
+}
+
+static int mcp25xxfd_chip_softreset(const struct mcp25xxfd_priv *priv)
+{
+       int err, i;
+
+       for (i = 0; i < MCP25XXFD_SOFTRESET_RETRIES_MAX; i++) {
+               if (i)
+                       netdev_info(priv->ndev,
+                                   "Retrying to reset Controller.\n");
+
+               err = mcp25xxfd_chip_softreset_do(priv);
+               if (err == -ETIMEDOUT)
+                       continue;
+               if (err)
+                       return err;
+
+               err = mcp25xxfd_chip_softreset_check(priv);
+               if (err == -ETIMEDOUT)
+                       continue;
+               if (err)
+                       return err;
+
+               return 0;
+       }
+
+       if (err)
+               return err;
+
+       return -ETIMEDOUT;
+}
+
+static int mcp25xxfd_chip_clock_init(const struct mcp25xxfd_priv *priv)
+{
+       u32 osc;
+       int err;
+
+       /* Activate Low Power Mode on Oscillator Disable. This only
+        * works on the MCP2518FD. The MCP2517FD will go into normal
+        * Sleep Mode instead.
+        */
+       osc = MCP25XXFD_REG_OSC_LPMEN |
+               FIELD_PREP(MCP25XXFD_REG_OSC_CLKODIV_MASK,
+                          MCP25XXFD_REG_OSC_CLKODIV_10);
+       err = regmap_write(priv->map_reg, MCP25XXFD_REG_OSC, osc);
+       if (err)
+               return err;
+
+       /* Set Time Base Counter Prescaler to 1.
+        *
+        * This means an overflow of the 32 bit Time Base Counter
+        * register at 40 MHz every 107 seconds.
+        */
+       return regmap_write(priv->map_reg, MCP25XXFD_REG_TSCON,
+                           MCP25XXFD_REG_TSCON_TBCEN);
+}
+
+static int mcp25xxfd_set_bittiming(const struct mcp25xxfd_priv *priv)
+{
+       const struct can_bittiming *bt = &priv->can.bittiming;
+       const struct can_bittiming *dbt = &priv->can.data_bittiming;
+       u32 val = 0;
+       s8 tdco;
+       int err;
+
+       /* CAN Control Register
+        *
+        * - no transmit bandwidth sharing
+        * - config mode
+        * - disable transmit queue
+        * - store in transmit FIFO event
+        * - transition to restricted operation mode on system error
+        * - ESI is transmitted recessive when ESI of message is high or
+        *   CAN controller error passive
+        * - restricted retransmission attempts,
+        *   use TQXCON_TXAT and FIFOCON_TXAT
+        * - wake-up filter bits T11FILTER
+        * - use CAN bus line filter for wakeup
+        * - protocol exception is treated as a form error
+        * - Do not compare data bytes
+        */
+       val = FIELD_PREP(MCP25XXFD_REG_CON_REQOP_MASK,
+                        MCP25XXFD_REG_CON_MODE_CONFIG) |
+               MCP25XXFD_REG_CON_STEF |
+               MCP25XXFD_REG_CON_ESIGM |
+               MCP25XXFD_REG_CON_RTXAT |
+               FIELD_PREP(MCP25XXFD_REG_CON_WFT_MASK,
+                          MCP25XXFD_REG_CON_WFT_T11FILTER) |
+               MCP25XXFD_REG_CON_WAKFIL |
+               MCP25XXFD_REG_CON_PXEDIS;
+
+       if (!(priv->can.ctrlmode & CAN_CTRLMODE_FD_NON_ISO))
+               val |= MCP25XXFD_REG_CON_ISOCRCEN;
+
+       err = regmap_write(priv->map_reg, MCP25XXFD_REG_CON, val);
+       if (err)
+               return err;
+
+       /* Nominal Bit Time */
+       val = FIELD_PREP(MCP25XXFD_REG_NBTCFG_BRP_MASK, bt->brp - 1) |
+               FIELD_PREP(MCP25XXFD_REG_NBTCFG_TSEG1_MASK,
+                          bt->prop_seg + bt->phase_seg1 - 1) |
+               FIELD_PREP(MCP25XXFD_REG_NBTCFG_TSEG2_MASK,
+                          bt->phase_seg2 - 1) |
+               FIELD_PREP(MCP25XXFD_REG_NBTCFG_SJW_MASK, bt->sjw - 1);
+
+       err = regmap_write(priv->map_reg, MCP25XXFD_REG_NBTCFG, val);
+       if (err)
+               return err;
+
+       if (!(priv->can.ctrlmode & CAN_CTRLMODE_FD))
+               return 0;
+
+       /* Data Bit Time */
+       val = FIELD_PREP(MCP25XXFD_REG_DBTCFG_BRP_MASK, dbt->brp - 1) |
+               FIELD_PREP(MCP25XXFD_REG_DBTCFG_TSEG1_MASK,
+                          dbt->prop_seg + dbt->phase_seg1 - 1) |
+               FIELD_PREP(MCP25XXFD_REG_DBTCFG_TSEG2_MASK,
+                          dbt->phase_seg2 - 1) |
+               FIELD_PREP(MCP25XXFD_REG_DBTCFG_SJW_MASK, dbt->sjw - 1);
+
+       err = regmap_write(priv->map_reg, MCP25XXFD_REG_DBTCFG, val);
+       if (err)
+               return err;
+
+       /* Transmitter Delay Compensation */
+       tdco = clamp_t(int, dbt->brp * (dbt->prop_seg + dbt->phase_seg1),
+                      -64, 63);
+       val = FIELD_PREP(MCP25XXFD_REG_TDC_TDCMOD_MASK,
+                        MCP25XXFD_REG_TDC_TDCMOD_AUTO) |
+               FIELD_PREP(MCP25XXFD_REG_TDC_TDCO_MASK, tdco);
+
+       return regmap_write(priv->map_reg, MCP25XXFD_REG_TDC, val);
+}
+
+static int mcp25xxfd_chip_rx_int_enable(const struct mcp25xxfd_priv *priv)
+{
+       u32 val;
+
+       if (!priv->rx_int)
+               return 0;
+
+       /* Configure GPIOs:
+        * - PIN0: GPIO Input
+        * - PIN1: GPIO Input/RX Interrupt
+        *
+        * PIN1 must be Input, otherwise there is a glitch on the
+        * rx-INT line. It happens between setting the PIN as output
+        * (in the first byte of the SPI transfer) and configuring the
+        * PIN as interrupt (in the last byte of the SPI transfer).
+        */
+       val = MCP25XXFD_REG_IOCON_PM0 | MCP25XXFD_REG_IOCON_TRIS1 |
+               MCP25XXFD_REG_IOCON_TRIS0;
+       return regmap_write(priv->map_reg, MCP25XXFD_REG_IOCON, val);
+}
+
+static int mcp25xxfd_chip_rx_int_disable(const struct mcp25xxfd_priv *priv)
+{
+       u32 val;
+
+       if (!priv->rx_int)
+               return 0;
+
+       /* Configure GPIOs:
+        * - PIN0: GPIO Input
+        * - PIN1: GPIO Input
+        */
+       val = MCP25XXFD_REG_IOCON_PM1 | MCP25XXFD_REG_IOCON_PM0 |
+               MCP25XXFD_REG_IOCON_TRIS1 | MCP25XXFD_REG_IOCON_TRIS0;
+       return regmap_write(priv->map_reg, MCP25XXFD_REG_IOCON, val);
+}
+
+static int
+mcp25xxfd_chip_rx_fifo_init_one(const struct mcp25xxfd_priv *priv,
+                               const struct mcp25xxfd_rx_ring *ring)
+{
+       u32 fifo_con;
+
+       /* Enable RXOVIE on _all_ RX FIFOs, not just the last one.
+        *
+        * FIFOs hit by a RX MAB overflow and RXOVIE enabled will
+        * generate a RXOVIF, use this to properly detect RX MAB
+        * overflows.
+        */
+       fifo_con = FIELD_PREP(MCP25XXFD_REG_FIFOCON_FSIZE_MASK,
+                             ring->obj_num - 1) |
+               MCP25XXFD_REG_FIFOCON_RXTSEN |
+               MCP25XXFD_REG_FIFOCON_RXOVIE |
+               MCP25XXFD_REG_FIFOCON_TFNRFNIE;
+
+       if (priv->can.ctrlmode & CAN_CTRLMODE_FD)
+               fifo_con |= FIELD_PREP(MCP25XXFD_REG_FIFOCON_PLSIZE_MASK,
+                                      MCP25XXFD_REG_FIFOCON_PLSIZE_64);
+       else
+               fifo_con |= FIELD_PREP(MCP25XXFD_REG_FIFOCON_PLSIZE_MASK,
+                                      MCP25XXFD_REG_FIFOCON_PLSIZE_8);
+
+       return regmap_write(priv->map_reg,
+                           MCP25XXFD_REG_FIFOCON(ring->fifo_nr), fifo_con);
+}
+
+static int
+mcp25xxfd_chip_rx_filter_init_one(const struct mcp25xxfd_priv *priv,
+                                 const struct mcp25xxfd_rx_ring *ring)
+{
+       u32 fltcon;
+
+       fltcon = MCP25XXFD_REG_FLTCON_FLTEN(ring->nr) |
+               MCP25XXFD_REG_FLTCON_FBP(ring->nr, ring->fifo_nr);
+
+       return regmap_update_bits(priv->map_reg,
+                                 MCP25XXFD_REG_FLTCON(ring->nr >> 2),
+                                 MCP25XXFD_REG_FLTCON_FLT_MASK(ring->nr),
+                                 fltcon);
+}
+
+static int mcp25xxfd_chip_fifo_init(const struct mcp25xxfd_priv *priv)
+{
+       const struct mcp25xxfd_tx_ring *tx_ring = priv->tx;
+       const struct mcp25xxfd_rx_ring *rx_ring;
+       u32 val;
+       int err, n;
+
+       /* TEF */
+       val = FIELD_PREP(MCP25XXFD_REG_TEFCON_FSIZE_MASK,
+                        tx_ring->obj_num - 1) |
+               MCP25XXFD_REG_TEFCON_TEFTSEN |
+               MCP25XXFD_REG_TEFCON_TEFOVIE |
+               MCP25XXFD_REG_TEFCON_TEFNEIE;
+
+       err = regmap_write(priv->map_reg, MCP25XXFD_REG_TEFCON, val);
+       if (err)
+               return err;
+
+       /* FIFO 1 - TX */
+       val = FIELD_PREP(MCP25XXFD_REG_FIFOCON_FSIZE_MASK,
+                        tx_ring->obj_num - 1) |
+               MCP25XXFD_REG_FIFOCON_TXEN |
+               MCP25XXFD_REG_FIFOCON_TXATIE;
+
+       if (priv->can.ctrlmode & CAN_CTRLMODE_FD)
+               val |= FIELD_PREP(MCP25XXFD_REG_FIFOCON_PLSIZE_MASK,
+                                 MCP25XXFD_REG_FIFOCON_PLSIZE_64);
+       else
+               val |= FIELD_PREP(MCP25XXFD_REG_FIFOCON_PLSIZE_MASK,
+                                 MCP25XXFD_REG_FIFOCON_PLSIZE_8);
+
+       if (priv->can.ctrlmode & CAN_CTRLMODE_ONE_SHOT)
+               val |= FIELD_PREP(MCP25XXFD_REG_FIFOCON_TXAT_MASK,
+                                 MCP25XXFD_REG_FIFOCON_TXAT_ONE_SHOT);
+       else
+               val |= FIELD_PREP(MCP25XXFD_REG_FIFOCON_TXAT_MASK,
+                                 MCP25XXFD_REG_FIFOCON_TXAT_UNLIMITED);
+
+       err = regmap_write(priv->map_reg,
+                          MCP25XXFD_REG_FIFOCON(MCP25XXFD_TX_FIFO),
+                          val);
+       if (err)
+               return err;
+
+       /* RX FIFOs */
+       mcp25xxfd_for_each_rx_ring(priv, rx_ring, n) {
+               err = mcp25xxfd_chip_rx_fifo_init_one(priv, rx_ring);
+               if (err)
+                       return err;
+
+               err = mcp25xxfd_chip_rx_filter_init_one(priv, rx_ring);
+               if (err)
+                       return err;
+       }
+
+       return 0;
+}
+
+static int mcp25xxfd_chip_ecc_init(struct mcp25xxfd_priv *priv)
+{
+       struct mcp25xxfd_ecc *ecc = &priv->ecc;
+       void *ram;
+       u32 val = 0;
+       int err;
+
+       ecc->ecc_stat = 0;
+
+       if (priv->devtype_data.quirks & MCP25XXFD_QUIRK_ECC)
+               val = MCP25XXFD_REG_ECCCON_ECCEN;
+
+       err = regmap_update_bits(priv->map_reg, MCP25XXFD_REG_ECCCON,
+                                MCP25XXFD_REG_ECCCON_ECCEN, val);
+       if (err)
+               return err;
+
+       ram = kzalloc(MCP25XXFD_RAM_SIZE, GFP_KERNEL);
+       if (!ram)
+               return -ENOMEM;
+
+       err = regmap_raw_write(priv->map_reg, MCP25XXFD_RAM_START, ram,
+                              MCP25XXFD_RAM_SIZE);
+       kfree(ram);
+
+       return err;
+}
+
+static inline void mcp25xxfd_ecc_tefif_successful(struct mcp25xxfd_priv *priv)
+{
+       struct mcp25xxfd_ecc *ecc = &priv->ecc;
+
+       ecc->ecc_stat = 0;
+}
+
+static u8 mcp25xxfd_get_normal_mode(const struct mcp25xxfd_priv *priv)
+{
+       u8 mode;
+
+       if (priv->can.ctrlmode & CAN_CTRLMODE_FD)
+               mode = MCP25XXFD_REG_CON_MODE_MIXED;
+       else
+               mode = MCP25XXFD_REG_CON_MODE_CAN2_0;
+
+       return mode;
+}
+
+static int
+__mcp25xxfd_chip_set_normal_mode(const struct mcp25xxfd_priv *priv,
+                                bool nowait)
+{
+       u8 mode;
+
+       mode = mcp25xxfd_get_normal_mode(priv);
+
+       return __mcp25xxfd_chip_set_mode(priv, mode, nowait);
+}
+
+static inline int
+mcp25xxfd_chip_set_normal_mode(const struct mcp25xxfd_priv *priv)
+{
+       return __mcp25xxfd_chip_set_normal_mode(priv, false);
+}
+
+static inline int
+mcp25xxfd_chip_set_normal_mode_nowait(const struct mcp25xxfd_priv *priv)
+{
+       return __mcp25xxfd_chip_set_normal_mode(priv, true);
+}
+
+static int mcp25xxfd_chip_interrupts_enable(const struct mcp25xxfd_priv *priv)
+{
+       u32 val;
+       int err;
+
+       val = MCP25XXFD_REG_CRC_FERRIE | MCP25XXFD_REG_CRC_CRCERRIE;
+       err = regmap_write(priv->map_reg, MCP25XXFD_REG_CRC, val);
+       if (err)
+               return err;
+
+       val = MCP25XXFD_REG_ECCCON_DEDIE | MCP25XXFD_REG_ECCCON_SECIE;
+       err = regmap_update_bits(priv->map_reg, MCP25XXFD_REG_ECCCON, val, val);
+       if (err)
+               return err;
+
+       val = MCP25XXFD_REG_INT_CERRIE |
+               MCP25XXFD_REG_INT_SERRIE |
+               MCP25XXFD_REG_INT_RXOVIE |
+               MCP25XXFD_REG_INT_TXATIE |
+               MCP25XXFD_REG_INT_SPICRCIE |
+               MCP25XXFD_REG_INT_ECCIE |
+               MCP25XXFD_REG_INT_TEFIE |
+               MCP25XXFD_REG_INT_MODIE |
+               MCP25XXFD_REG_INT_RXIE;
+
+       if (priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING)
+               val |= MCP25XXFD_REG_INT_IVMIE;
+
+       return regmap_write(priv->map_reg, MCP25XXFD_REG_INT, val);
+}
+
+static int mcp25xxfd_chip_interrupts_disable(const struct mcp25xxfd_priv *priv)
+{
+       int err;
+       u32 mask;
+
+       err = regmap_write(priv->map_reg, MCP25XXFD_REG_INT, 0);
+       if (err)
+               return err;
+
+       mask = MCP25XXFD_REG_ECCCON_DEDIE | MCP25XXFD_REG_ECCCON_SECIE;
+       err = regmap_update_bits(priv->map_reg, MCP25XXFD_REG_ECCCON,
+                                mask, 0x0);
+       if (err)
+               return err;
+
+       return regmap_write(priv->map_reg, MCP25XXFD_REG_CRC, 0);
+}
+
+static int mcp25xxfd_chip_stop(struct mcp25xxfd_priv *priv,
+                              const enum can_state state)
+{
+       priv->can.state = state;
+
+       mcp25xxfd_chip_interrupts_disable(priv);
+       mcp25xxfd_chip_rx_int_disable(priv);
+       return mcp25xxfd_chip_set_mode(priv, MCP25XXFD_REG_CON_MODE_SLEEP);
+}
+
+static int mcp25xxfd_chip_start(struct mcp25xxfd_priv *priv)
+{
+       int err;
+
+       err = mcp25xxfd_chip_softreset(priv);
+       if (err)
+               goto out_chip_stop;
+
+       err = mcp25xxfd_chip_clock_init(priv);
+       if (err)
+               goto out_chip_stop;
+
+       err = mcp25xxfd_set_bittiming(priv);
+       if (err)
+               goto out_chip_stop;
+
+       err = mcp25xxfd_chip_rx_int_enable(priv);
+       if (err)
+               return err;
+
+       err = mcp25xxfd_chip_ecc_init(priv);
+       if (err)
+               goto out_chip_stop;
+
+       mcp25xxfd_ring_init(priv);
+
+       err = mcp25xxfd_chip_fifo_init(priv);
+       if (err)
+               goto out_chip_stop;
+
+       priv->can.state = CAN_STATE_ERROR_ACTIVE;
+
+       err = mcp25xxfd_chip_set_normal_mode(priv);
+       if (err)
+               goto out_chip_stop;
+
+       return 0;
+
+ out_chip_stop:
+       mcp25xxfd_chip_stop(priv, CAN_STATE_STOPPED);
+
+       return err;
+}
+
+static int mcp25xxfd_set_mode(struct net_device *ndev, enum can_mode mode)
+{
+       struct mcp25xxfd_priv *priv = netdev_priv(ndev);
+       int err;
+
+       switch (mode) {
+       case CAN_MODE_START:
+               err = mcp25xxfd_chip_start(priv);
+               if (err)
+                       return err;
+
+               err = mcp25xxfd_chip_interrupts_enable(priv);
+               if (err) {
+                       mcp25xxfd_chip_stop(priv, CAN_STATE_STOPPED);
+                       return err;
+               }
+
+               netif_wake_queue(ndev);
+               break;
+
+       default:
+               return -EOPNOTSUPP;
+       }
+
+       return 0;
+}
+
+static int __mcp25xxfd_get_berr_counter(const struct net_device *ndev,
+                                       struct can_berr_counter *bec)
+{
+       const struct mcp25xxfd_priv *priv = netdev_priv(ndev);
+       u32 trec;
+       int err;
+
+       err = regmap_read(priv->map_reg, MCP25XXFD_REG_TREC, &trec);
+       if (err)
+               return err;
+
+       if (trec & MCP25XXFD_REG_TREC_TXBO)
+               bec->txerr = 256;
+       else
+               bec->txerr = FIELD_GET(MCP25XXFD_REG_TREC_TEC_MASK, trec);
+       bec->rxerr = FIELD_GET(MCP25XXFD_REG_TREC_REC_MASK, trec);
+
+       return 0;
+}
+
+static int mcp25xxfd_get_berr_counter(const struct net_device *ndev,
+                                     struct can_berr_counter *bec)
+{
+       const struct mcp25xxfd_priv *priv = netdev_priv(ndev);
+
+       /* Avoid waking up the controller if the interface is down */
+       if (!(ndev->flags & IFF_UP))
+               return 0;
+
+       /* The controller is powered down during Bus Off, use saved
+        * bec values.
+        */
+       if (priv->can.state == CAN_STATE_BUS_OFF) {
+               *bec = priv->bec;
+               return 0;
+       }
+
+       return __mcp25xxfd_get_berr_counter(ndev, bec);
+}
+
+static int mcp25xxfd_check_tef_tail(const struct mcp25xxfd_priv *priv)
+{
+       u8 tef_tail_chip, tef_tail;
+       int err;
+
+       if (!IS_ENABLED(CONFIG_CAN_MCP25XXFD_SANITY))
+               return 0;
+
+       err = mcp25xxfd_tef_tail_get_from_chip(priv, &tef_tail_chip);
+       if (err)
+               return err;
+
+       tef_tail = mcp25xxfd_get_tef_tail(priv);
+       if (tef_tail_chip != tef_tail) {
+               netdev_err(priv->ndev,
+                          "TEF tail of chip (0x%02x) and ours (0x%08x) inconsistent.\n",
+                          tef_tail_chip, tef_tail);
+               return -EILSEQ;
+       }
+
+       return 0;
+}
+
+static int
+mcp25xxfd_check_rx_tail(const struct mcp25xxfd_priv *priv,
+                       const struct mcp25xxfd_rx_ring *ring)
+{
+       u8 rx_tail_chip, rx_tail;
+       int err;
+
+       if (!IS_ENABLED(CONFIG_CAN_MCP25XXFD_SANITY))
+               return 0;
+
+       err = mcp25xxfd_rx_tail_get_from_chip(priv, ring, &rx_tail_chip);
+       if (err)
+               return err;
+
+       rx_tail = mcp25xxfd_get_rx_tail(ring);
+       if (rx_tail_chip != rx_tail) {
+               netdev_err(priv->ndev,
+                          "RX tail of chip (%d) and ours (%d) inconsistent.\n",
+                          rx_tail_chip, rx_tail);
+               return -EILSEQ;
+       }
+
+       return 0;
+}
+
+static int
+mcp25xxfd_handle_tefif_recover(const struct mcp25xxfd_priv *priv, const u32 seq)
+{
+       const struct mcp25xxfd_tx_ring *tx_ring = priv->tx;
+       u32 tef_sta;
+       int err;
+
+       err = regmap_read(priv->map_reg, MCP25XXFD_REG_TEFSTA, &tef_sta);
+       if (err)
+               return err;
+
+       if (tef_sta & MCP25XXFD_REG_TEFSTA_TEFOVIF) {
+               netdev_err(priv->ndev,
+                          "Transmit Event FIFO buffer overflow.\n");
+               return -ENOBUFS;
+       }
+
+       netdev_info(priv->ndev,
+                   "Transmit Event FIFO buffer %s. (seq=0x%08x, tef_tail=0x%08x, tef_head=0x%08x, tx_head=0x%08x)\n",
+                   tef_sta & MCP25XXFD_REG_TEFSTA_TEFFIF ?
+                   "full" : tef_sta & MCP25XXFD_REG_TEFSTA_TEFNEIF ?
+                   "not empty" : "empty",
+                   seq, priv->tef.tail, priv->tef.head, tx_ring->head);
+
+       /* The Sequence Number in the TEF doesn't match our tef_tail. */
+       return -EAGAIN;
+}
+
+static int
+mcp25xxfd_handle_tefif_one(struct mcp25xxfd_priv *priv,
+                          const struct mcp25xxfd_hw_tef_obj *hw_tef_obj)
+{
+       struct mcp25xxfd_tx_ring *tx_ring = priv->tx;
+       struct net_device_stats *stats = &priv->ndev->stats;
+       u32 seq, seq_masked, tef_tail_masked;
+       int err;
+
+       seq = FIELD_GET(MCP25XXFD_OBJ_FLAGS_SEQ_MCP2518FD_MASK,
+                       hw_tef_obj->flags);
+
+       /* Use the MCP2517FD mask on the MCP2518FD, too. We only
+        * compare 7 bits, this should be enough to detect
+        * net-yet-completed, i.e. old TEF objects.
+        */
+       seq_masked = seq &
+               field_mask(MCP25XXFD_OBJ_FLAGS_SEQ_MCP2517FD_MASK);
+       tef_tail_masked = priv->tef.tail &
+               field_mask(MCP25XXFD_OBJ_FLAGS_SEQ_MCP2517FD_MASK);
+       if (seq_masked != tef_tail_masked)
+               return mcp25xxfd_handle_tefif_recover(priv, seq);
+
+       stats->tx_bytes +=
+               can_rx_offload_get_echo_skb(&priv->offload,
+                                           mcp25xxfd_get_tef_tail(priv),
+                                           hw_tef_obj->ts);
+       stats->tx_packets++;
+
+       /* finally increment the TEF pointer */
+       err = regmap_update_bits(priv->map_reg, MCP25XXFD_REG_TEFCON,
+                                GENMASK(15, 8),
+                                MCP25XXFD_REG_TEFCON_UINC);
+       if (err)
+               return err;
+
+       priv->tef.tail++;
+       tx_ring->tail++;
+
+       return mcp25xxfd_check_tef_tail(priv);
+}
+
+static int mcp25xxfd_tef_ring_update(struct mcp25xxfd_priv *priv)
+{
+       const struct mcp25xxfd_tx_ring *tx_ring = priv->tx;
+       unsigned int new_head;
+       u8 chip_tx_tail;
+       int err;
+
+       err = mcp25xxfd_tx_tail_get_from_chip(priv, &chip_tx_tail);
+       if (err)
+               return err;
+
+       /* chip_tx_tail, is the next TX-Object send by the HW.
+        * The new TEF head must be >= the old head, ...
+        */
+       new_head = round_down(priv->tef.head, tx_ring->obj_num) + chip_tx_tail;
+       if (new_head <= priv->tef.head)
+               new_head += tx_ring->obj_num;
+
+       /* ... but it cannot exceed the TX head. */
+       priv->tef.head = min(new_head, tx_ring->head);
+
+       return mcp25xxfd_check_tef_tail(priv);
+}
+
+static inline int
+mcp25xxfd_tef_obj_read(const struct mcp25xxfd_priv *priv,
+                      struct mcp25xxfd_hw_tef_obj *hw_tef_obj,
+                      const u8 offset, const u8 len)
+{
+       const struct mcp25xxfd_tx_ring *tx_ring = priv->tx;
+
+       if (IS_ENABLED(CONFIG_CAN_MCP25XXFD_SANITY) &&
+           (offset > tx_ring->obj_num ||
+            len > tx_ring->obj_num ||
+            offset + len > tx_ring->obj_num)) {
+               netdev_err(priv->ndev,
+                          "Trying to read to many TEF objects (max=%d, offset=%d, len=%d).\n",
+                          tx_ring->obj_num, offset, len);
+               return -ERANGE;
+       }
+
+       return regmap_bulk_read(priv->map_rx,
+                               mcp25xxfd_get_tef_obj_addr(offset),
+                               hw_tef_obj,
+                               sizeof(*hw_tef_obj) / sizeof(u32) * len);
+}
+
+static int mcp25xxfd_handle_tefif(struct mcp25xxfd_priv *priv)
+{
+       struct mcp25xxfd_hw_tef_obj hw_tef_obj[MCP25XXFD_TX_OBJ_NUM_MAX];
+       u8 tef_tail, len, l;
+       int err, i;
+
+       err = mcp25xxfd_tef_ring_update(priv);
+       if (err)
+               return err;
+
+       tef_tail = mcp25xxfd_get_tef_tail(priv);
+       len = mcp25xxfd_get_tef_len(priv);
+       l = mcp25xxfd_get_tef_linear_len(priv);
+       err = mcp25xxfd_tef_obj_read(priv, hw_tef_obj, tef_tail, l);
+       if (err)
+               return err;
+
+       if (l < len) {
+               err = mcp25xxfd_tef_obj_read(priv, &hw_tef_obj[l], 0, len - l);
+               if (err)
+                       return err;
+       }
+
+       for (i = 0; i < len; i++) {
+               err = mcp25xxfd_handle_tefif_one(priv, &hw_tef_obj[i]);
+               /* -EAGAIN means the Sequence Number in the TEF
+                * doesn't match our tef_tail. This can happen if we
+                * read the TEF objects too early. Leave loop let the
+                * interrupt handler call us again.
+                */
+               if (err == -EAGAIN)
+                       goto out_netif_wake_queue;
+               if (err)
+                       return err;
+       }
+
+ out_netif_wake_queue:
+       mcp25xxfd_ecc_tefif_successful(priv);
+
+       if (mcp25xxfd_get_tx_free(priv->tx)) {
+               /* Make sure that anybody stopping the queue after
+                * this sees the new tx_ring->tail.
+                */
+               smp_mb();
+               netif_wake_queue(priv->ndev);
+       }
+
+       return 0;
+}
+
+static int
+mcp25xxfd_rx_ring_update(const struct mcp25xxfd_priv *priv,
+                        struct mcp25xxfd_rx_ring *ring)
+{
+       u32 new_head;
+       u8 chip_rx_head;
+       int err;
+
+       err = mcp25xxfd_rx_head_get_from_chip(priv, ring, &chip_rx_head);
+       if (err)
+               return err;
+
+       /* chip_rx_head, is the next RX-Object filled by the HW.
+        * The new RX head must be >= the old head.
+        */
+       new_head = round_down(ring->head, ring->obj_num) + chip_rx_head;
+       if (new_head <= ring->head)
+               new_head += ring->obj_num;
+
+       ring->head = new_head;
+
+       return mcp25xxfd_check_rx_tail(priv, ring);
+}
+
+static void
+mcp25xxfd_hw_rx_obj_to_skb(const struct mcp25xxfd_priv *priv,
+                          const struct mcp25xxfd_hw_rx_obj_canfd *hw_rx_obj,
+                          struct sk_buff *skb)
+{
+       struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
+
+       if (hw_rx_obj->flags & MCP25XXFD_OBJ_FLAGS_IDE) {
+               u32 sid, eid;
+
+               eid = FIELD_GET(MCP25XXFD_OBJ_ID_EID_MASK, hw_rx_obj->id);
+               sid = FIELD_GET(MCP25XXFD_OBJ_ID_SID_MASK, hw_rx_obj->id);
+
+               cfd->can_id = CAN_EFF_FLAG |
+                       FIELD_PREP(MCP25XXFD_REG_FRAME_EFF_EID_MASK, eid) |
+                       FIELD_PREP(MCP25XXFD_REG_FRAME_EFF_SID_MASK, sid);
+       } else {
+               cfd->can_id = FIELD_GET(MCP25XXFD_OBJ_ID_SID_MASK,
+                                       hw_rx_obj->id);
+       }
+
+       /* CANFD */
+       if (hw_rx_obj->flags & MCP25XXFD_OBJ_FLAGS_FDF) {
+               u8 dlc;
+
+               if (hw_rx_obj->flags & MCP25XXFD_OBJ_FLAGS_ESI)
+                       cfd->flags |= CANFD_ESI;
+
+               if (hw_rx_obj->flags & MCP25XXFD_OBJ_FLAGS_BRS)
+                       cfd->flags |= CANFD_BRS;
+
+               dlc = FIELD_GET(MCP25XXFD_OBJ_FLAGS_DLC, hw_rx_obj->flags);
+               cfd->len = can_dlc2len(get_canfd_dlc(dlc));
+       } else {
+               if (hw_rx_obj->flags & MCP25XXFD_OBJ_FLAGS_RTR)
+                       cfd->can_id |= CAN_RTR_FLAG;
+
+               cfd->len = get_can_dlc(FIELD_GET(MCP25XXFD_OBJ_FLAGS_DLC,
+                                                hw_rx_obj->flags));
+       }
+
+       memcpy(cfd->data, hw_rx_obj->data, cfd->len);
+}
+
+static int
+mcp25xxfd_handle_rxif_one(struct mcp25xxfd_priv *priv,
+                         struct mcp25xxfd_rx_ring *ring,
+                         const struct mcp25xxfd_hw_rx_obj_canfd *hw_rx_obj)
+{
+       struct net_device_stats *stats = &priv->ndev->stats;
+       struct sk_buff *skb;
+       struct canfd_frame *cfd;
+       int err;
+
+       if (hw_rx_obj->flags & MCP25XXFD_OBJ_FLAGS_FDF)
+               skb = alloc_canfd_skb(priv->ndev, &cfd);
+       else
+               skb = alloc_can_skb(priv->ndev, (struct can_frame **)&cfd);
+
+       if (!cfd) {
+               stats->rx_dropped++;
+               return 0;
+       }
+
+       mcp25xxfd_hw_rx_obj_to_skb(priv, hw_rx_obj, skb);
+       err = can_rx_offload_queue_sorted(&priv->offload, skb, hw_rx_obj->ts);
+       if (err)
+               stats->rx_fifo_errors++;
+
+       ring->tail++;
+
+       /* finally increment the RX pointer */
+       return regmap_update_bits(priv->map_reg,
+                                 MCP25XXFD_REG_FIFOCON(ring->fifo_nr),
+                                 GENMASK(15, 8),
+                                 MCP25XXFD_REG_FIFOCON_UINC);
+}
+
+static inline int
+mcp25xxfd_rx_obj_read(const struct mcp25xxfd_priv *priv,
+                     const struct mcp25xxfd_rx_ring *ring,
+                     struct mcp25xxfd_hw_rx_obj_canfd *hw_rx_obj,
+                     const u8 offset, const u8 len)
+{
+       int err;
+
+       err = regmap_bulk_read(priv->map_rx,
+                              mcp25xxfd_get_rx_obj_addr(ring, offset),
+                              hw_rx_obj,
+                              len * ring->obj_size / sizeof(u32));
+
+       return err;
+}
+
+static int
+mcp25xxfd_handle_rxif_ring(struct mcp25xxfd_priv *priv,
+                          struct mcp25xxfd_rx_ring *ring)
+{
+       struct mcp25xxfd_hw_rx_obj_canfd *hw_rx_obj = ring->obj;
+       u8 rx_tail, len;
+       int err, i;
+
+       err = mcp25xxfd_rx_ring_update(priv, ring);
+       if (err)
+               return err;
+
+       while ((len = mcp25xxfd_get_rx_linear_len(ring))) {
+               rx_tail = mcp25xxfd_get_rx_tail(ring);
+
+               err = mcp25xxfd_rx_obj_read(priv, ring, hw_rx_obj,
+                                           rx_tail, len);
+               if (err)
+                       return err;
+
+               for (i = 0; i < len; i++) {
+                       err = mcp25xxfd_handle_rxif_one(priv, ring,
+                                                       (void *)hw_rx_obj +
+                                                       i * ring->obj_size);
+                       if (err)
+                               return err;
+               }
+       }
+
+       return 0;
+}
+
+static int mcp25xxfd_handle_rxif(struct mcp25xxfd_priv *priv)
+{
+       struct mcp25xxfd_rx_ring *ring;
+       int err, n;
+
+       mcp25xxfd_for_each_rx_ring(priv, ring, n) {
+               err = mcp25xxfd_handle_rxif_ring(priv, ring);
+               if (err)
+                       return err;
+       }
+
+       return 0;
+}
+
+static inline int mcp25xxfd_get_timestamp(const struct mcp25xxfd_priv *priv,
+                                         u32 *timestamp)
+{
+       return regmap_read(priv->map_reg, MCP25XXFD_REG_TBC, timestamp);
+}
+
+static struct sk_buff *
+mcp25xxfd_alloc_can_err_skb(const struct mcp25xxfd_priv *priv,
+                           struct can_frame **cf, u32 *timestamp)
+{
+       int err;
+
+       err = mcp25xxfd_get_timestamp(priv, timestamp);
+       if (err)
+               return NULL;
+
+       return alloc_can_err_skb(priv->ndev, cf);
+}
+
+static int mcp25xxfd_handle_rxovif(struct mcp25xxfd_priv *priv)
+{
+       struct net_device_stats *stats = &priv->ndev->stats;
+       struct mcp25xxfd_rx_ring *ring;
+       struct sk_buff *skb;
+       struct can_frame *cf;
+       u32 timestamp, rxovif;
+       int err, i;
+
+       stats->rx_over_errors++;
+       stats->rx_errors++;
+
+       err = regmap_read(priv->map_reg, MCP25XXFD_REG_RXOVIF, &rxovif);
+       if (err)
+               return err;
+
+       mcp25xxfd_for_each_rx_ring(priv, ring, i) {
+               if (!(rxovif & BIT(ring->fifo_nr)))
+                       continue;
+
+               /* If SERRIF is active, there was a RX MAB overflow. */
+               if (priv->regs_status.intf & MCP25XXFD_REG_INT_SERRIF) {
+                       netdev_info(priv->ndev,
+                                   "RX-%d: MAB overflow detected.\n",
+                                   ring->nr);
+               } else {
+                       netdev_info(priv->ndev,
+                                   "RX-%d: FIFO overflow.\n", ring->nr);
+               }
+
+               err = regmap_update_bits(priv->map_reg,
+                                        MCP25XXFD_REG_FIFOSTA(ring->fifo_nr),
+                                        MCP25XXFD_REG_FIFOSTA_RXOVIF,
+                                        0x0);
+               if (err)
+                       return err;
+       }
+
+       skb = mcp25xxfd_alloc_can_err_skb(priv, &cf, &timestamp);
+       if (!skb)
+               return 0;
+
+       cf->can_id |= CAN_ERR_CRTL;
+       cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
+
+       err = can_rx_offload_queue_sorted(&priv->offload, skb, timestamp);
+       if (err)
+               stats->rx_fifo_errors++;
+
+       return 0;
+}
+
+static int mcp25xxfd_handle_txatif(struct mcp25xxfd_priv *priv)
+{
+       netdev_info(priv->ndev, "%s\n", __func__);
+
+       return 0;
+}
+
+static int mcp25xxfd_handle_ivmif(struct mcp25xxfd_priv *priv)
+{
+       struct net_device_stats *stats = &priv->ndev->stats;
+       u32 bdiag1, timestamp;
+       struct sk_buff *skb;
+       struct can_frame *cf = NULL;
+       int err;
+
+       err = mcp25xxfd_get_timestamp(priv, &timestamp);
+       if (err)
+               return err;
+
+       err = regmap_read(priv->map_reg, MCP25XXFD_REG_BDIAG1, &bdiag1);
+       if (err)
+               return err;
+
+       /* Write 0s to clear error bits, don't write 1s to non active
+        * bits, as they will be set.
+        */
+       err = regmap_write(priv->map_reg, MCP25XXFD_REG_BDIAG1, 0x0);
+       if (err)
+               return err;
+
+       priv->can.can_stats.bus_error++;
+
+       skb = alloc_can_err_skb(priv->ndev, &cf);
+       if (cf)
+               cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
+
+       /* Controller misconfiguration */
+       if (WARN_ON(bdiag1 & MCP25XXFD_REG_BDIAG1_DLCMM))
+               netdev_err(priv->ndev,
+                          "recv'd DLC is larger than PLSIZE of FIFO element.");
+
+       /* RX errors */
+       if (bdiag1 & (MCP25XXFD_REG_BDIAG1_DCRCERR |
+                     MCP25XXFD_REG_BDIAG1_NCRCERR)) {
+               netdev_dbg(priv->ndev, "CRC error\n");
+
+               stats->rx_errors++;
+               if (cf)
+                       cf->data[3] |= CAN_ERR_PROT_LOC_CRC_SEQ;
+       }
+       if (bdiag1 & (MCP25XXFD_REG_BDIAG1_DSTUFERR |
+                     MCP25XXFD_REG_BDIAG1_NSTUFERR)) {
+               netdev_dbg(priv->ndev, "Stuff error\n");
+
+               stats->rx_errors++;
+               if (cf)
+                       cf->data[2] |= CAN_ERR_PROT_STUFF;
+       }
+       if (bdiag1 & (MCP25XXFD_REG_BDIAG1_DFORMERR |
+                     MCP25XXFD_REG_BDIAG1_NFORMERR)) {
+               netdev_dbg(priv->ndev, "Format error\n");
+
+               stats->rx_errors++;
+               if (cf)
+                       cf->data[2] |= CAN_ERR_PROT_FORM;
+       }
+
+       /* TX errors */
+       if (bdiag1 & MCP25XXFD_REG_BDIAG1_NACKERR) {
+               netdev_dbg(priv->ndev, "NACK error\n");
+
+               stats->tx_errors++;
+               if (cf) {
+                       cf->can_id |= CAN_ERR_ACK;
+                       cf->data[2] |= CAN_ERR_PROT_TX;
+               }
+       }
+       if (bdiag1 & (MCP25XXFD_REG_BDIAG1_DBIT1ERR |
+                     MCP25XXFD_REG_BDIAG1_NBIT1ERR)) {
+               netdev_dbg(priv->ndev, "Bit1 error\n");
+
+               stats->tx_errors++;
+               if (cf)
+                       cf->data[2] |= CAN_ERR_PROT_TX | CAN_ERR_PROT_BIT1;
+       }
+       if (bdiag1 & (MCP25XXFD_REG_BDIAG1_DBIT0ERR |
+                     MCP25XXFD_REG_BDIAG1_NBIT0ERR)) {
+               netdev_dbg(priv->ndev, "Bit0 error\n");
+
+               stats->tx_errors++;
+               if (cf)
+                       cf->data[2] |= CAN_ERR_PROT_TX | CAN_ERR_PROT_BIT0;
+       }
+
+       if (!cf)
+               return 0;
+
+       err = can_rx_offload_queue_sorted(&priv->offload, skb, timestamp);
+       if (err)
+               stats->rx_fifo_errors++;
+
+       return 0;
+}
+
+static int mcp25xxfd_handle_cerrif(struct mcp25xxfd_priv *priv)
+{
+       struct net_device_stats *stats = &priv->ndev->stats;
+       struct sk_buff *skb;
+       struct can_frame *cf = NULL;
+       enum can_state new_state, rx_state, tx_state;
+       u32 trec, timestamp;
+       int err;
+
+       err = regmap_read(priv->map_reg, MCP25XXFD_REG_TREC, &trec);
+       if (err)
+               return err;
+
+       if (trec & MCP25XXFD_REG_TREC_TXBO)
+               tx_state = CAN_STATE_BUS_OFF;
+       else if (trec & MCP25XXFD_REG_TREC_TXBP)
+               tx_state = CAN_STATE_ERROR_PASSIVE;
+       else if (trec & MCP25XXFD_REG_TREC_TXWARN)
+               tx_state = CAN_STATE_ERROR_WARNING;
+       else
+               tx_state = CAN_STATE_ERROR_ACTIVE;
+
+       if (trec & MCP25XXFD_REG_TREC_RXBP)
+               rx_state = CAN_STATE_ERROR_PASSIVE;
+       else if (trec & MCP25XXFD_REG_TREC_RXWARN)
+               rx_state = CAN_STATE_ERROR_WARNING;
+       else
+               rx_state = CAN_STATE_ERROR_ACTIVE;
+
+       new_state = max(tx_state, rx_state);
+       if (new_state == priv->can.state)
+               return 0;
+
+       /* The skb allocation might fail, but can_change_state()
+        * handles cf == NULL.
+        */
+       skb = mcp25xxfd_alloc_can_err_skb(priv, &cf, &timestamp);
+       can_change_state(priv->ndev, cf, tx_state, rx_state);
+
+       if (new_state == CAN_STATE_BUS_OFF) {
+               /* As we're going to switch off the chip now, let's
+                * save the error counters and return them to
+                * userspace, if do_get_berr_counter() is called while
+                * the chip is in Bus Off.
+                */
+               err = __mcp25xxfd_get_berr_counter(priv->ndev, &priv->bec);
+               if (err)
+                       return err;
+
+               mcp25xxfd_chip_stop(priv, CAN_STATE_BUS_OFF);
+               can_bus_off(priv->ndev);
+       }
+
+       if (!skb)
+               return 0;
+
+       if (new_state != CAN_STATE_BUS_OFF) {
+               struct can_berr_counter bec;
+
+               err = mcp25xxfd_get_berr_counter(priv->ndev, &bec);
+               if (err)
+                       return err;
+               cf->data[6] = bec.txerr;
+               cf->data[7] = bec.rxerr;
+       }
+
+       err = can_rx_offload_queue_sorted(&priv->offload, skb, timestamp);
+       if (err)
+               stats->rx_fifo_errors++;
+
+       return 0;
+}
+
+static int
+mcp25xxfd_handle_modif(const struct mcp25xxfd_priv *priv, bool *set_normal_mode)
+{
+       const u8 mode_reference = mcp25xxfd_get_normal_mode(priv);
+       u8 mode;
+       int err;
+
+       err = mcp25xxfd_chip_get_mode(priv, &mode);
+       if (err)
+               return err;
+
+       if (mode == mode_reference) {
+               netdev_dbg(priv->ndev,
+                          "Controller changed into %s Mode (%u).\n",
+                          mcp25xxfd_get_mode_str(mode), mode);
+               return 0;
+       }
+
+       /* According to MCP2517FD errata DS80000792B 1., during a TX
+        * MAB underflow, the controller will transition to Restricted
+        * Operation Mode or Listen Only Mode (depending on SERR2LOM).
+        *
+        * However this is not always the case. If SERR2LOM is
+        * configured for Restricted Operation Mode (SERR2LOM not set)
+        * the MCP2517FD will sometimes transition to Listen Only Mode
+        * first. When polling this bit we see that it will transition
+        * to Restricted Operation Mode shortly after.
+        */
+       if ((priv->devtype_data.quirks & MCP25XXFD_QUIRK_MAB_NO_WARN) &&
+           (mode == MCP25XXFD_REG_CON_MODE_RESTRICTED ||
+            mode == MCP25XXFD_REG_CON_MODE_LISTENONLY))
+               netdev_dbg(priv->ndev,
+                          "Controller changed into %s Mode (%u).\n",
+                          mcp25xxfd_get_mode_str(mode), mode);
+       else
+               netdev_err(priv->ndev,
+                          "Controller changed into %s Mode (%u).\n",
+                          mcp25xxfd_get_mode_str(mode), mode);
+
+       /* After the application requests Normal mode, the Controller
+        * will automatically attempt to retransmit the message that
+        * caused the TX MAB underflow.
+        *
+        * However, if there is an ECC error in the TX-RAM, we first
+        * have to reload the tx-object before requesting Normal
+        * mode. This is done later in mcp25xxfd_handle_eccif().
+        */
+       if (priv->regs_status.intf & MCP25XXFD_REG_INT_ECCIF) {
+               *set_normal_mode = true;
+               return 0;
+       }
+
+       return mcp25xxfd_chip_set_normal_mode_nowait(priv);
+}
+
+static int mcp25xxfd_handle_serrif(struct mcp25xxfd_priv *priv)
+{
+       struct mcp25xxfd_ecc *ecc = &priv->ecc;
+       struct net_device_stats *stats = &priv->ndev->stats;
+       bool handled = false;
+
+       /* TX MAB underflow
+        *
+        * According to MCP2517FD Errata DS80000792B 1. a TX MAB
+        * underflow is indicated by SERRIF and MODIF.
+        *
+        * In addition to the effects mentioned in the Errata, there
+        * are Bus Errors due to the aborted CAN frame, so a IVMIF
+        * will be seen as well.
+        *
+        * Sometimes there is an ECC error in the TX-RAM, which leads
+        * to a TX MAB underflow.
+        *
+        * However, probably due to a race condition, there is no
+        * associated MODIF pending.
+        *
+        * Further, there are situations, where the SERRIF is caused
+        * by an ECC error in the TX-RAM, but not even the ECCIF is
+        * set. This only seems to happen _after_ the first occurrence
+        * of a ECCIF (which is tracked in ecc->cnt).
+        *
+        * Treat all as a known system errors..
+        */
+       if ((priv->regs_status.intf & MCP25XXFD_REG_INT_MODIF &&
+            priv->regs_status.intf & MCP25XXFD_REG_INT_IVMIF) ||
+           priv->regs_status.intf & MCP25XXFD_REG_INT_ECCIF ||
+           ecc->cnt) {
+               const char *msg;
+
+               if (priv->regs_status.intf & MCP25XXFD_REG_INT_ECCIF ||
+                   ecc->cnt)
+                       msg = "TX MAB underflow due to ECC error detected.";
+               else
+                       msg = "TX MAB underflow detected.";
+
+               if (priv->devtype_data.quirks & MCP25XXFD_QUIRK_MAB_NO_WARN)
+                       netdev_dbg(priv->ndev, "%s\n", msg);
+               else
+                       netdev_info(priv->ndev, "%s\n", msg);
+
+               stats->tx_aborted_errors++;
+               stats->tx_errors++;
+               handled = true;
+       }
+
+       /* RX MAB overflow
+        *
+        * According to MCP2517FD Errata DS80000792B 1. a RX MAB
+        * overflow is indicated by SERRIF.
+        *
+        * In addition to the effects mentioned in the Errata, (most
+        * of the times) a RXOVIF is raised, if the FIFO that is being
+        * received into has the RXOVIE activated (and we have enabled
+        * RXOVIE on all FIFOs).
+        *
+        * Sometimes there is no RXOVIF just a RXIF is pending.
+        *
+        * Treat all as a known system errors..
+        */
+       if (priv->regs_status.intf & MCP25XXFD_REG_INT_RXOVIF ||
+           priv->regs_status.intf & MCP25XXFD_REG_INT_RXIF) {
+               stats->rx_dropped++;
+               handled = true;
+       }
+
+       if (!handled)
+               netdev_err(priv->ndev,
+                          "Unhandled System Error Interrupt (intf=0x%08x)!\n",
+                          priv->regs_status.intf);
+
+       return 0;
+}
+
+static int
+mcp25xxfd_handle_eccif_recover(struct mcp25xxfd_priv *priv, u8 nr)
+{
+       struct mcp25xxfd_tx_ring *tx_ring = priv->tx;
+       struct mcp25xxfd_ecc *ecc = &priv->ecc;
+       struct mcp25xxfd_tx_obj *tx_obj;
+       u8 chip_tx_tail, tx_tail, offset;
+       u16 addr;
+       int err;
+
+       addr = FIELD_GET(MCP25XXFD_REG_ECCSTAT_ERRADDR_MASK, ecc->ecc_stat);
+
+       err = mcp25xxfd_tx_tail_get_from_chip(priv, &chip_tx_tail);
+       if (err)
+               return err;
+
+       tx_tail = mcp25xxfd_get_tx_tail(tx_ring);
+       offset = (nr - chip_tx_tail) & (tx_ring->obj_num - 1);
+
+       /* Bail out if one of the following is met:
+        * - tx_tail information is inconsistent
+        * - for mcp2517fd: offset not 0
+        * - for mcp2518fd: offset not 0 or 1
+        */
+       if (chip_tx_tail != tx_tail ||
+           !(offset == 0 || (offset == 1 && mcp25xxfd_is_2518(priv)))) {
+               netdev_err(priv->ndev,
+                          "ECC Error information inconsistent (addr=0x%04x, nr=%d, tx_tail=0x%08x(%d), chip_tx_tail=%d, offset=%d).\n",
+                          addr, nr, tx_ring->tail, tx_tail, chip_tx_tail,
+                          offset);
+               return -EINVAL;
+       }
+
+       netdev_info(priv->ndev,
+                   "Recovering %s ECC Error at address 0x%04x (in TX-RAM, tx_obj=%d, tx_tail=0x%08x(%d), offset=%d).\n",
+                   ecc->ecc_stat & MCP25XXFD_REG_ECCSTAT_SECIF ?
+                   "Single" : "Double",
+                   addr, nr, tx_ring->tail, tx_tail, offset);
+
+       /* reload tx_obj into controller RAM ... */
+       tx_obj = &tx_ring->obj[nr];
+       err = spi_sync_transfer(priv->spi, tx_obj->xfer, 1);
+       if (err)
+               return err;
+
+       /* ... and trigger retransmit */
+       return mcp25xxfd_chip_set_normal_mode(priv);
+}
+
+static int
+mcp25xxfd_handle_eccif(struct mcp25xxfd_priv *priv, bool set_normal_mode)
+{
+       struct mcp25xxfd_ecc *ecc = &priv->ecc;
+       const char *msg;
+       bool in_tx_ram;
+       u32 ecc_stat;
+       u16 addr;
+       u8 nr;
+       int err;
+
+       err = regmap_read(priv->map_reg, MCP25XXFD_REG_ECCSTAT, &ecc_stat);
+       if (err)
+               return err;
+
+       err = regmap_update_bits(priv->map_reg, MCP25XXFD_REG_ECCSTAT,
+                                MCP25XXFD_REG_ECCSTAT_IF_MASK, ~ecc_stat);
+       if (err)
+               return err;
+
+       /* Check if ECC error occurred in TX-RAM */
+       addr = FIELD_GET(MCP25XXFD_REG_ECCSTAT_ERRADDR_MASK, ecc_stat);
+       err = mcp25xxfd_get_tx_nr_by_addr(priv->tx, &nr, addr);
+       if (!err)
+               in_tx_ram = true;
+       else if (err == -ENOENT)
+               in_tx_ram = false;
+       else
+               return err;
+
+       if (ecc_stat & MCP25XXFD_REG_ECCSTAT_SECIF)
+               msg = "Single ECC Error corrected at address";
+       else if (ecc_stat & MCP25XXFD_REG_ECCSTAT_DEDIF)
+               msg = "Double ECC Error detected at address";
+       else
+               return -EINVAL;
+
+       if (!in_tx_ram) {
+               ecc->ecc_stat = 0;
+
+               if (ecc_stat & MCP25XXFD_REG_ECCSTAT_SECIF)
+                       netdev_info(priv->ndev, "%s 0x%04x.\n",
+                                   msg, addr);
+               else
+                       netdev_notice(priv->ndev, "%s 0x%04x.\n",
+                                     msg, addr);
+       } else {
+               /* Re-occurring error? */
+               if (ecc->ecc_stat == ecc_stat) {
+                       ecc->cnt++;
+               } else {
+                       ecc->ecc_stat = ecc_stat;
+                       ecc->cnt = 1;
+               }
+
+               netdev_info(priv->ndev,
+                           "%s 0x%04x (in TX-RAM, tx_obj=%d), occurred %d time%s.\n",
+                           msg, addr, nr, ecc->cnt, ecc->cnt > 1 ? "s" : "");
+
+               if (ecc->cnt >= MCP25XXFD_ECC_CNT_MAX)
+                       return mcp25xxfd_handle_eccif_recover(priv, nr);
+       }
+
+       if (set_normal_mode)
+               return mcp25xxfd_chip_set_normal_mode_nowait(priv);
+
+       return 0;
+}
+
+static int mcp25xxfd_handle_spicrcif(struct mcp25xxfd_priv *priv)
+{
+       int err;
+       u32 crc;
+
+       err = regmap_read(priv->map_reg, MCP25XXFD_REG_CRC, &crc);
+       if (err)
+               return err;
+
+       err = regmap_update_bits(priv->map_reg, MCP25XXFD_REG_CRC,
+                                MCP25XXFD_REG_CRC_IF_MASK,
+                                ~crc);
+       if (err)
+               return err;
+
+       if (crc & MCP25XXFD_REG_CRC_FERRIF)
+               netdev_notice(priv->ndev, "CRC write command format error.\n");
+       else if (crc & MCP25XXFD_REG_CRC_CRCERRIF)
+               netdev_notice(priv->ndev,
+                             "CRC write error detected. CRC=0x%04lx.\n",
+                             FIELD_GET(MCP25XXFD_REG_CRC_MASK, crc));
+
+       return 0;
+}
+
+#define mcp25xxfd_handle(priv, irq, ...) \
+({ \
+       struct mcp25xxfd_priv *_priv = (priv); \
+       int err; \
+\
+       err = mcp25xxfd_handle_##irq(_priv, ## __VA_ARGS__); \
+       if (err) \
+               netdev_err(_priv->ndev, \
+                       "IRQ handler mcp25xxfd_handle_%s() returned %d.\n", \
+                       __stringify(irq), err); \
+       err; \
+})
+
+static irqreturn_t mcp25xxfd_irq(int irq, void *dev_id)
+{
+       struct mcp25xxfd_priv *priv = dev_id;
+       irqreturn_t handled = IRQ_NONE;
+       int err;
+
+       if (priv->rx_int)
+               do {
+                       int rx_pending;
+
+                       rx_pending = gpiod_get_value_cansleep(priv->rx_int);
+                       if (!rx_pending)
+                               break;
+
+                       err = mcp25xxfd_handle(priv, rxif);
+                       if (err)
+                               goto out_fail;
+
+                       handled = IRQ_HANDLED;
+               } while (1);
+
+       do {
+               u32 intf_pending, intf_pending_clearable;
+               bool set_normal_mode;
+
+               err = regmap_bulk_read(priv->map_reg, MCP25XXFD_REG_INT,
+                                      &priv->regs_status,
+                                      sizeof(priv->regs_status) /
+                                      sizeof(u32));
+               if (err)
+                       goto out_fail;
+
+               intf_pending = FIELD_GET(MCP25XXFD_REG_INT_IF_MASK,
+                                        priv->regs_status.intf) &
+                       FIELD_GET(MCP25XXFD_REG_INT_IE_MASK,
+                                 priv->regs_status.intf);
+
+               if (!(intf_pending))
+                       return handled;
+
+               /* Some interrupts must be ACKed in the
+                * MCP25XXFD_REG_INT register.
+                * - First ACK then handle, to avoid lost-IRQ race
+                *   condition on fast re-occurring interrupts.
+                * - Write "0" to clear active IRQs, "1" to all other,
+                *   to avoid r/m/w race condition on the
+                *   MCP25XXFD_REG_INT register.
+                */
+               intf_pending_clearable = intf_pending &
+                       MCP25XXFD_REG_INT_IF_CLEARABLE_MASK;
+               if (intf_pending_clearable) {
+                       err = regmap_update_bits(priv->map_reg,
+                                                MCP25XXFD_REG_INT,
+                                                MCP25XXFD_REG_INT_IF_MASK,
+                                                ~intf_pending_clearable);
+                       if (err)
+                               goto out_fail;
+               }
+
+               if (intf_pending & MCP25XXFD_REG_INT_MODIF) {
+                       err = mcp25xxfd_handle(priv, modif, &set_normal_mode);
+                       if (err)
+                               goto out_fail;
+               }
+
+               if (intf_pending & MCP25XXFD_REG_INT_RXIF) {
+                       err = mcp25xxfd_handle(priv, rxif);
+                       if (err)
+                               goto out_fail;
+               }
+
+               if (intf_pending & MCP25XXFD_REG_INT_TEFIF) {
+                       err = mcp25xxfd_handle(priv, tefif);
+                       if (err)
+                               goto out_fail;
+               }
+
+               if (intf_pending & MCP25XXFD_REG_INT_RXOVIF) {
+                       err = mcp25xxfd_handle(priv, rxovif);
+                       if (err)
+                               goto out_fail;
+               }
+
+               if (intf_pending & MCP25XXFD_REG_INT_TXATIF) {
+                       err = mcp25xxfd_handle(priv, txatif);
+                       if (err)
+                               goto out_fail;
+               }
+
+               if (intf_pending & MCP25XXFD_REG_INT_IVMIF) {
+                       err = mcp25xxfd_handle(priv, ivmif);
+                       if (err)
+                               goto out_fail;
+               }
+
+               if (intf_pending & MCP25XXFD_REG_INT_SERRIF) {
+                       err = mcp25xxfd_handle(priv, serrif);
+                       if (err)
+                               goto out_fail;
+               }
+
+               if (intf_pending & MCP25XXFD_REG_INT_ECCIF) {
+                       err = mcp25xxfd_handle(priv, eccif, set_normal_mode);
+                       if (err)
+                               goto out_fail;
+               }
+
+               if (intf_pending & MCP25XXFD_REG_INT_SPICRCIF) {
+                       err = mcp25xxfd_handle(priv, spicrcif);
+                       if (err)
+                               goto out_fail;
+               }
+
+               /* On the MCP2527FD and MCP2518FD, we don't get a
+                * CERRIF IRQ on the transition TX ERROR_WARNING -> TX
+                * ERROR_ACTIVE.
+                */
+               if (intf_pending & MCP25XXFD_REG_INT_CERRIF ||
+                   priv->can.state > CAN_STATE_ERROR_ACTIVE) {
+                       err = mcp25xxfd_handle(priv, cerrif);
+                       if (err)
+                               goto out_fail;
+
+                       /* In Bus Off we completely shut down the
+                        * controller. Every subsequent register read
+                        * will read bogus data, and if
+                        * MCP25XXFD_QUIRK_CRC_REG is enabled the CRC
+                        * check will fail, too. So leave IRQ handler
+                        * directly.
+                        */
+                       if (priv->can.state == CAN_STATE_BUS_OFF)
+                               return IRQ_HANDLED;
+               }
+
+               handled = IRQ_HANDLED;
+       } while (1);
+
+ out_fail:
+       netdev_err(priv->ndev, "IRQ handler returned %d (intf=0x%08x).\n",
+                  err, priv->regs_status.intf);
+       mcp25xxfd_chip_interrupts_disable(priv);
+
+       return handled;
+}
+
+static inline struct
+mcp25xxfd_tx_obj *mcp25xxfd_get_tx_obj_next(struct mcp25xxfd_tx_ring *tx_ring)
+{
+       u8 tx_head;
+
+       tx_head = mcp25xxfd_get_tx_head(tx_ring);
+
+       return &tx_ring->obj[tx_head];
+}
+
+static void
+mcp25xxfd_tx_obj_from_skb(const struct mcp25xxfd_priv *priv,
+                         struct mcp25xxfd_tx_obj *tx_obj,
+                         const struct sk_buff *skb,
+                         unsigned int seq)
+{
+       const struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
+       struct mcp25xxfd_hw_tx_obj_raw *hw_tx_obj;
+       union mcp25xxfd_tx_obj_load_buf *load_buf;
+       u8 dlc;
+       u32 id, flags;
+       int offset, len;
+
+       if (cfd->can_id & CAN_EFF_FLAG) {
+               u32 sid, eid;
+
+               sid = FIELD_GET(MCP25XXFD_REG_FRAME_EFF_SID_MASK, cfd->can_id);
+               eid = FIELD_GET(MCP25XXFD_REG_FRAME_EFF_EID_MASK, cfd->can_id);
+
+               id = FIELD_PREP(MCP25XXFD_OBJ_ID_EID_MASK, eid) |
+                       FIELD_PREP(MCP25XXFD_OBJ_ID_SID_MASK, sid);
+
+               flags = MCP25XXFD_OBJ_FLAGS_IDE;
+       } else {
+               id = FIELD_PREP(MCP25XXFD_OBJ_ID_SID_MASK, cfd->can_id);
+               flags = 0;
+       }
+
+       /* Use the MCP2518FD mask even on the MCP2517FD. It doesn't
+        * harm, only the lower 7 bits will be transferred into the
+        * TEF object.
+        */
+       dlc = can_len2dlc(cfd->len);
+       flags |= FIELD_PREP(MCP25XXFD_OBJ_FLAGS_SEQ_MCP2518FD_MASK, seq) |
+               FIELD_PREP(MCP25XXFD_OBJ_FLAGS_DLC, dlc);
+
+       if (cfd->can_id & CAN_RTR_FLAG)
+               flags |= MCP25XXFD_OBJ_FLAGS_RTR;
+
+       /* CANFD */
+       if (can_is_canfd_skb(skb)) {
+               if (cfd->flags & CANFD_ESI)
+                       flags |= MCP25XXFD_OBJ_FLAGS_ESI;
+
+               flags |= MCP25XXFD_OBJ_FLAGS_FDF;
+
+               if (cfd->flags & CANFD_BRS)
+                       flags |= MCP25XXFD_OBJ_FLAGS_BRS;
+       }
+
+       load_buf = &tx_obj->buf;
+       if (priv->devtype_data.quirks & MCP25XXFD_QUIRK_CRC_TX)
+               hw_tx_obj = &load_buf->crc.hw_tx_obj;
+       else
+               hw_tx_obj = &load_buf->nocrc.hw_tx_obj;
+
+       put_unaligned_le32(id, &hw_tx_obj->id);
+       put_unaligned_le32(flags, &hw_tx_obj->flags);
+
+       /* Clear data at end of CAN frame */
+       offset = round_down(cfd->len, sizeof(u32));
+       len = round_up(can_dlc2len(dlc), sizeof(u32)) - offset;
+       if (MCP25XXFD_SANITIZE_CAN && len)
+               memset(hw_tx_obj->data + offset, 0x0, len);
+       memcpy(hw_tx_obj->data, cfd->data, cfd->len);
+
+       /* Number of bytes to be written into the RAM of the controller */
+       len = sizeof(hw_tx_obj->id) + sizeof(hw_tx_obj->flags);
+       if (MCP25XXFD_SANITIZE_CAN)
+               len += round_up(can_dlc2len(dlc), sizeof(u32));
+       else
+               len += round_up(cfd->len, sizeof(u32));
+
+       if (priv->devtype_data.quirks & MCP25XXFD_QUIRK_CRC_TX) {
+               u16 crc;
+
+               mcp25xxfd_spi_cmd_crc_set_len_in_ram(&load_buf->crc.cmd,
+                                                    len);
+               /* CRC */
+               len += sizeof(load_buf->crc.cmd);
+               crc = mcp25xxfd_crc16_compute(&load_buf->crc, len);
+               put_unaligned_be16(crc, (void *)load_buf + len);
+
+               /* Total length */
+               len += sizeof(load_buf->crc.crc);
+       } else {
+               len += sizeof(load_buf->nocrc.cmd);
+       }
+
+       tx_obj->xfer[0].len = len;
+}
+
+static int mcp25xxfd_tx_obj_write(const struct mcp25xxfd_priv *priv,
+                                 struct mcp25xxfd_tx_obj *tx_obj)
+{
+       return spi_async(priv->spi, &tx_obj->msg);
+}
+
+static bool mcp25xxfd_tx_busy(const struct mcp25xxfd_priv *priv,
+                             struct mcp25xxfd_tx_ring *tx_ring)
+{
+       if (mcp25xxfd_get_tx_free(tx_ring) > 0)
+               return false;
+
+       netif_stop_queue(priv->ndev);
+
+       /* Memory barrier before checking tx_free (head and tail) */
+       smp_mb();
+
+       if (mcp25xxfd_get_tx_free(tx_ring) == 0) {
+               netdev_dbg(priv->ndev,
+                          "Stopping tx-queue (tx_head=0x%08x, tx_tail=0x%08x, len=%d).\n",
+                          tx_ring->head, tx_ring->tail,
+                          tx_ring->head - tx_ring->tail);
+
+               return true;
+       }
+
+       netif_start_queue(priv->ndev);
+
+       return false;
+}
+
+static netdev_tx_t mcp25xxfd_start_xmit(struct sk_buff *skb,
+                                       struct net_device *ndev)
+{
+       struct mcp25xxfd_priv *priv = netdev_priv(ndev);
+       struct mcp25xxfd_tx_ring *tx_ring = priv->tx;
+       struct mcp25xxfd_tx_obj *tx_obj;
+       u8 tx_head;
+       int err;
+
+       if (can_dropped_invalid_skb(ndev, skb))
+               return NETDEV_TX_OK;
+
+       if (mcp25xxfd_tx_busy(priv, tx_ring))
+               return NETDEV_TX_BUSY;
+
+       tx_obj = mcp25xxfd_get_tx_obj_next(tx_ring);
+       mcp25xxfd_tx_obj_from_skb(priv, tx_obj, skb, tx_ring->head);
+
+       /* Stop queue if we occupy the complete TX FIFO */
+       tx_head = mcp25xxfd_get_tx_head(tx_ring);
+       tx_ring->head++;
+       if (tx_ring->head - tx_ring->tail >= tx_ring->obj_num)
+               netif_stop_queue(ndev);
+
+       can_put_echo_skb(skb, ndev, tx_head);
+
+       err = mcp25xxfd_tx_obj_write(priv, tx_obj);
+       if (err)
+               goto out_err;
+
+       return NETDEV_TX_OK;
+
+ out_err:
+       netdev_err(priv->ndev, "ERROR in %s: %d\n", __func__, err);
+
+       return NETDEV_TX_OK;
+}
+
+static int mcp25xxfd_open(struct net_device *ndev)
+{
+       struct mcp25xxfd_priv *priv = netdev_priv(ndev);
+       const struct spi_device *spi = priv->spi;
+       int err;
+
+       err = pm_runtime_get_sync(ndev->dev.parent);
+       if (err < 0) {
+               pm_runtime_put_noidle(ndev->dev.parent);
+               return err;
+       }
+
+       err = open_candev(ndev);
+       if (err)
+               goto out_pm_runtime_put;
+
+       err = mcp25xxfd_ring_alloc(priv);
+       if (err)
+               goto out_close_candev;
+
+       err = mcp25xxfd_transceiver_enable(priv);
+       if (err)
+               goto out_mcp25xxfd_ring_free;
+
+       err = mcp25xxfd_chip_start(priv);
+       if (err)
+               goto out_transceiver_disable;
+
+       can_rx_offload_enable(&priv->offload);
+
+       err = request_threaded_irq(spi->irq, NULL, mcp25xxfd_irq,
+                                  IRQF_ONESHOT, dev_name(&spi->dev),
+                                  priv);
+       if (err)
+               goto out_can_rx_offload_disable;
+
+       err = mcp25xxfd_chip_interrupts_enable(priv);
+       if (err)
+               goto out_free_irq;
+
+       netif_start_queue(ndev);
+
+       return 0;
+
+ out_free_irq:
+       free_irq(spi->irq, priv);
+ out_can_rx_offload_disable:
+       can_rx_offload_disable(&priv->offload);
+ out_transceiver_disable:
+       mcp25xxfd_transceiver_disable(priv);
+ out_mcp25xxfd_ring_free:
+       mcp25xxfd_ring_free(priv);
+ out_close_candev:
+       close_candev(ndev);
+ out_pm_runtime_put:
+       mcp25xxfd_chip_stop(priv, CAN_STATE_STOPPED);
+       pm_runtime_put(ndev->dev.parent);
+
+       return err;
+}
+
+static int mcp25xxfd_stop(struct net_device *ndev)
+{
+       struct mcp25xxfd_priv *priv = netdev_priv(ndev);
+
+       netif_stop_queue(ndev);
+       mcp25xxfd_chip_interrupts_disable(priv);
+       free_irq(ndev->irq, priv);
+       can_rx_offload_disable(&priv->offload);
+       mcp25xxfd_chip_stop(priv, CAN_STATE_STOPPED);
+       mcp25xxfd_transceiver_disable(priv);
+       mcp25xxfd_ring_free(priv);
+       close_candev(ndev);
+
+       pm_runtime_put(ndev->dev.parent);
+
+       return 0;
+}
+
+static const struct net_device_ops mcp25xxfd_netdev_ops = {
+       .ndo_open = mcp25xxfd_open,
+       .ndo_stop = mcp25xxfd_stop,
+       .ndo_start_xmit = mcp25xxfd_start_xmit,
+       .ndo_change_mtu = can_change_mtu,
+};
+
+static void
+mcp25xxfd_register_quirks(struct mcp25xxfd_priv *priv)
+{
+       const struct spi_device *spi = priv->spi;
+       const struct spi_controller *ctlr = spi->controller;
+
+       if (ctlr->flags & SPI_CONTROLLER_HALF_DUPLEX)
+               priv->devtype_data.quirks |= MCP25XXFD_QUIRK_HALF_DUPLEX;
+}
+
+static int mcp25xxfd_register_chip_detect(struct mcp25xxfd_priv *priv)
+{
+       const struct net_device *ndev = priv->ndev;
+       const struct mcp25xxfd_devtype_data *devtype_data;
+       u32 osc;
+       int err;
+
+       /* The OSC_LPMEN is only supported on MCP2518FD, so use it to
+        * autodetect the model.
+        */
+       err = regmap_update_bits(priv->map_reg, MCP25XXFD_REG_OSC,
+                                MCP25XXFD_REG_OSC_LPMEN,
+                                MCP25XXFD_REG_OSC_LPMEN);
+       if (err)
+               return err;
+
+       err = regmap_read(priv->map_reg, MCP25XXFD_REG_OSC, &osc);
+       if (err)
+               return err;
+
+       if (osc & MCP25XXFD_REG_OSC_LPMEN)
+               devtype_data = &mcp25xxfd_devtype_data_mcp2518fd;
+       else
+               devtype_data = &mcp25xxfd_devtype_data_mcp2517fd;
+
+       if (!mcp25xxfd_is_25XX(priv) &&
+           priv->devtype_data.model != devtype_data->model) {
+               netdev_info(ndev,
+                           "Detected %s, but firmware specifies a %s. Fixing up.",
+                           __mcp25xxfd_get_model_str(devtype_data->model),
+                           mcp25xxfd_get_model_str(priv));
+       }
+       priv->devtype_data = *devtype_data;
+
+       /* We need to preserve the Half Duplex Quirk. */
+       mcp25xxfd_register_quirks(priv);
+
+       /* Re-init regmap with quirks of detected model. */
+       return mcp25xxfd_regmap_init(priv);
+}
+
+static int mcp25xxfd_register_check_rx_int(struct mcp25xxfd_priv *priv)
+{
+       int err, rx_pending;
+
+       if (!priv->rx_int)
+               return 0;
+
+       err = mcp25xxfd_chip_rx_int_enable(priv);
+       if (err)
+               return err;
+
+       /* Check if RX_INT is properly working. The RX_INT should not
+        * be active after a softreset.
+        */
+       rx_pending = gpiod_get_value_cansleep(priv->rx_int);
+
+       err = mcp25xxfd_chip_rx_int_disable(priv);
+       if (err)
+               return err;
+
+       if (!rx_pending)
+               return 0;
+
+       netdev_info(priv->ndev,
+                   "RX_INT active after softreset, disabling RX_INT support.");
+       devm_gpiod_put(&priv->spi->dev, priv->rx_int);
+       priv->rx_int = NULL;
+
+       return 0;
+}
+
+static int
+mcp25xxfd_register_get_dev_id(const struct mcp25xxfd_priv *priv,
+                             u32 *dev_id, u32 *effective_speed_hz)
+{
+       struct mcp25xxfd_map_buf_nocrc *buf_rx;
+       struct mcp25xxfd_map_buf_nocrc *buf_tx;
+       struct spi_transfer xfer[2] = { };
+       int err;
+
+       buf_rx = kzalloc(sizeof(*buf_rx), GFP_KERNEL);
+       if (!buf_rx)
+               return -ENOMEM;
+
+       buf_tx = kzalloc(sizeof(*buf_tx), GFP_KERNEL);
+       if (!buf_tx) {
+               err = -ENOMEM;
+               goto out_kfree_buf_rx;
+       }
+
+       xfer[0].tx_buf = buf_tx;
+       xfer[0].len = sizeof(buf_tx->cmd);
+       xfer[1].rx_buf = buf_rx->data;
+       xfer[1].len = sizeof(dev_id);
+
+       mcp25xxfd_spi_cmd_read_nocrc(&buf_tx->cmd, MCP25XXFD_REG_DEVID);
+       err = spi_sync_transfer(priv->spi, xfer, ARRAY_SIZE(xfer));
+       if (err)
+               goto out_kfree_buf_tx;
+
+       *dev_id = be32_to_cpup((__be32 *)buf_rx->data);
+       *effective_speed_hz = xfer->effective_speed_hz;
+
+ out_kfree_buf_tx:
+       kfree(buf_tx);
+ out_kfree_buf_rx:
+       kfree(buf_rx);
+
+       return 0;
+}
+
+#define MCP25XXFD_QUIRK_ACTIVE(quirk) \
+       (priv->devtype_data.quirks & MCP25XXFD_QUIRK_##quirk ? '+' : '-')
+
+static int
+mcp25xxfd_register_done(const struct mcp25xxfd_priv *priv)
+{
+       u32 dev_id, effective_speed_hz;
+       int err;
+
+       err = mcp25xxfd_register_get_dev_id(priv, &dev_id,
+                                           &effective_speed_hz);
+       if (err)
+               return err;
+
+       netdev_info(priv->ndev,
+                   "%s rev%lu.%lu (%cRX_INT %cMAB_NO_WARN %cCRC_REG %cCRC_RX %cCRC_TX %cECC %cHD c:%u.%02uMHz m:%u.%02uMHz r:%u.%02uMHz e:%u.%02uMHz) successfully initialized.\n",
+                   mcp25xxfd_get_model_str(priv),
+                   FIELD_GET(MCP25XXFD_REG_DEVID_ID_MASK, dev_id),
+                   FIELD_GET(MCP25XXFD_REG_DEVID_REV_MASK, dev_id),
+                   priv->rx_int ? '+' : '-',
+                   MCP25XXFD_QUIRK_ACTIVE(MAB_NO_WARN),
+                   MCP25XXFD_QUIRK_ACTIVE(CRC_REG),
+                   MCP25XXFD_QUIRK_ACTIVE(CRC_RX),
+                   MCP25XXFD_QUIRK_ACTIVE(CRC_TX),
+                   MCP25XXFD_QUIRK_ACTIVE(ECC),
+                   MCP25XXFD_QUIRK_ACTIVE(HALF_DUPLEX),
+                   priv->can.clock.freq / 1000000,
+                   priv->can.clock.freq % 1000000 / 1000 / 10,
+                   priv->spi_max_speed_hz_orig / 1000000,
+                   priv->spi_max_speed_hz_orig % 1000000 / 1000 / 10,
+                   priv->spi->max_speed_hz / 1000000,
+                   priv->spi->max_speed_hz % 1000000 / 1000 / 10,
+                   effective_speed_hz / 1000000,
+                   effective_speed_hz % 1000000 / 1000 / 10);
+
+       return 0;
+}
+
+static int mcp25xxfd_register(struct mcp25xxfd_priv *priv)
+{
+       struct net_device *ndev = priv->ndev;
+       int err;
+
+       err = mcp25xxfd_clks_and_vdd_enable(priv);
+       if (err)
+               return err;
+
+       pm_runtime_get_noresume(ndev->dev.parent);
+       err = pm_runtime_set_active(ndev->dev.parent);
+       if (err)
+               goto out_runtime_put_noidle;
+       pm_runtime_enable(ndev->dev.parent);
+
+       mcp25xxfd_register_quirks(priv);
+
+       err = mcp25xxfd_chip_softreset(priv);
+       if (err == -ENODEV)
+               goto out_runtime_disable;
+       if (err)
+               goto out_chip_set_mode_sleep;
+
+       err = mcp25xxfd_register_chip_detect(priv);
+       if (err)
+               goto out_chip_set_mode_sleep;
+
+       err = mcp25xxfd_register_check_rx_int(priv);
+       if (err)
+               goto out_chip_set_mode_sleep;
+
+       err = register_candev(ndev);
+       if (err)
+               goto out_chip_set_mode_sleep;
+
+       err = mcp25xxfd_register_done(priv);
+       if (err)
+               goto out_unregister_candev;
+
+       /* Put controller into sleep mode and let pm_runtime_put()
+        * disable the clocks and vdd. If CONFIG_PM is not enabled,
+        * the clocks and vdd will stay powered.
+        */
+       err = mcp25xxfd_chip_set_mode(priv, MCP25XXFD_REG_CON_MODE_SLEEP);
+       if (err)
+               goto out_unregister_candev;
+
+       pm_runtime_put(ndev->dev.parent);
+
+       return 0;
+
+ out_unregister_candev:
+       unregister_candev(ndev);
+ out_chip_set_mode_sleep:
+       mcp25xxfd_chip_set_mode(priv, MCP25XXFD_REG_CON_MODE_SLEEP);
+ out_runtime_disable:
+       pm_runtime_disable(ndev->dev.parent);
+ out_runtime_put_noidle:
+       pm_runtime_put_noidle(ndev->dev.parent);
+       mcp25xxfd_clks_and_vdd_disable(priv);
+
+       return err;
+}
+
+static inline void mcp25xxfd_unregister(struct mcp25xxfd_priv *priv)
+{
+       struct net_device *ndev = priv->ndev;
+
+       unregister_candev(ndev);
+
+       pm_runtime_get_sync(ndev->dev.parent);
+       pm_runtime_put_noidle(ndev->dev.parent);
+       mcp25xxfd_clks_and_vdd_disable(priv);
+       pm_runtime_disable(ndev->dev.parent);
+}
+
+static const struct of_device_id mcp25xxfd_of_match[] = {
+       {
+               .compatible = "microchip,mcp2517fd",
+               .data = &mcp25xxfd_devtype_data_mcp2517fd,
+       }, {
+               .compatible = "microchip,mcp2518fd",
+               .data = &mcp25xxfd_devtype_data_mcp2518fd,
+       }, {
+               .compatible = "microchip,mcp25xxfd",
+               .data = &mcp25xxfd_devtype_data_mcp25xxfd,
+       }, {
+               /* sentinel */
+       },
+};
+MODULE_DEVICE_TABLE(of, mcp25xxfd_of_match);
+
+static const struct spi_device_id mcp25xxfd_id_table[] = {
+       {
+               .name = "mcp2517fd",
+               .driver_data = (kernel_ulong_t)&mcp25xxfd_devtype_data_mcp2517fd,
+       }, {
+               .name = "mcp2518fd",
+               .driver_data = (kernel_ulong_t)&mcp25xxfd_devtype_data_mcp2518fd,
+       }, {
+               .name = "mcp25xxfd",
+               .driver_data = (kernel_ulong_t)&mcp25xxfd_devtype_data_mcp25xxfd,
+       }, {
+               /* sentinel */
+       },
+};
+MODULE_DEVICE_TABLE(spi, mcp25xxfd_id_table);
+
+static int mcp25xxfd_probe(struct spi_device *spi)
+{
+       const void *match;
+       struct net_device *ndev;
+       struct mcp25xxfd_priv *priv;
+       struct gpio_desc *rx_int;
+       struct regulator *reg_vdd, *reg_xceiver;
+       struct clk *clk;
+       u32 freq;
+       int err;
+
+       rx_int = devm_gpiod_get_optional(&spi->dev, "microchip,rx-int",
+                                        GPIOD_IN);
+       if (PTR_ERR(rx_int) == -EPROBE_DEFER)
+               return -EPROBE_DEFER;
+       else if (IS_ERR(rx_int))
+               return PTR_ERR(rx_int);
+
+       reg_vdd = devm_regulator_get_optional(&spi->dev, "vdd");
+       if (PTR_ERR(reg_vdd) == -EPROBE_DEFER)
+               return -EPROBE_DEFER;
+       else if (PTR_ERR(reg_vdd) == -ENODEV)
+               reg_vdd = NULL;
+       else if (IS_ERR(reg_vdd))
+               return PTR_ERR(reg_vdd);
+
+       reg_xceiver = devm_regulator_get_optional(&spi->dev, "xceiver");
+       if (PTR_ERR(reg_xceiver) == -EPROBE_DEFER)
+               return -EPROBE_DEFER;
+       else if (PTR_ERR(reg_xceiver) == -ENODEV)
+               reg_xceiver = NULL;
+       else if (IS_ERR(reg_xceiver))
+               return PTR_ERR(reg_xceiver);
+
+       clk = devm_clk_get(&spi->dev, NULL);
+       if (IS_ERR(clk)) {
+               dev_err(&spi->dev, "No Oscillator (clock) defined.\n");
+               return PTR_ERR(clk);
+       }
+       freq = clk_get_rate(clk);
+
+       /* Sanity check */
+       if (freq < MCP25XXFD_SYSCLOCK_HZ_MIN ||
+           freq > MCP25XXFD_SYSCLOCK_HZ_MAX) {
+               dev_err(&spi->dev,
+                       "Oscillator frequency (%u Hz) is too low or high.\n",
+                       freq);
+               return -ERANGE;
+       }
+
+       if (freq <= MCP25XXFD_SYSCLOCK_HZ_MAX / MCP25XXFD_OSC_PLL_MULTIPLIER) {
+               dev_err(&spi->dev,
+                       "Oscillator frequency (%u Hz) is too low and PLL is not supported.\n",
+                       freq);
+               return -ERANGE;
+       }
+
+       ndev = alloc_candev(sizeof(struct mcp25xxfd_priv),
+                           MCP25XXFD_TX_OBJ_NUM_MAX);
+       if (!ndev)
+               return -ENOMEM;
+
+       SET_NETDEV_DEV(ndev, &spi->dev);
+
+       ndev->netdev_ops = &mcp25xxfd_netdev_ops;
+       ndev->irq = spi->irq;
+       ndev->flags |= IFF_ECHO;
+
+       priv = netdev_priv(ndev);
+       spi_set_drvdata(spi, priv);
+       priv->can.clock.freq = freq;
+       priv->can.do_set_mode = mcp25xxfd_set_mode;
+       priv->can.do_get_berr_counter = mcp25xxfd_get_berr_counter;
+       priv->can.bittiming_const = &mcp25xxfd_bittiming_const;
+       priv->can.data_bittiming_const = &mcp25xxfd_data_bittiming_const;
+       priv->can.ctrlmode_supported = CAN_CTRLMODE_BERR_REPORTING |
+               CAN_CTRLMODE_FD | CAN_CTRLMODE_FD_NON_ISO;
+       priv->ndev = ndev;
+       priv->spi = spi;
+       priv->rx_int = rx_int;
+       priv->clk = clk;
+       priv->reg_vdd = reg_vdd;
+       priv->reg_xceiver = reg_xceiver;
+
+       match = device_get_match_data(&spi->dev);
+       if (match)
+               priv->devtype_data = *(struct mcp25xxfd_devtype_data *)match;
+       else
+               priv->devtype_data = *(struct mcp25xxfd_devtype_data *)
+                       spi_get_device_id(spi)->driver_data;
+
+       /* According to the datasheet the SPI clock must be less or
+        * equal SYSCLOCK / 2.
+        *
+        * It turns out, that the Controller is not stable at this
+        * rate. Known good and bad combinations are:
+        *
+        * MCP  ext-clk SoC                     SPI                     SPI-clk         max-clk parent-clk      Status  config
+        *
+        * 2518 20 MHz  allwinner,sun8i-h3      allwinner,sun8i-h3-spi   8333333 Hz      83.33% 600000000 Hz    good    assigned-clocks = <&ccu CLK_SPIx>
+        * 2518 20 MHz  allwinner,sun8i-h3      allwinner,sun8i-h3-spi   9375000 Hz      93.75% 600000000 Hz    bad     assigned-clocks = <&ccu CLK_SPIx>
+        * 2518 40 MHz  allwinner,sun8i-h3      allwinner,sun8i-h3-spi  16666667 Hz      83.33% 600000000 Hz    good    assigned-clocks = <&ccu CLK_SPIx>
+        * 2518 40 MHz  allwinner,sun8i-h3      allwinner,sun8i-h3-spi  18750000 Hz      93.75% 600000000 Hz    bad     assigned-clocks = <&ccu CLK_SPIx>
+        * 2517 20 MHz  fsl,imx8mm              fsl,imx51-ecspi          8333333 Hz      83.33%  16666667 Hz    good    assigned-clocks = <&clk IMX8MM_CLK_ECSPIx_ROOT>
+        * 2517 20 MHz  fsl,imx8mm              fsl,imx51-ecspi          9523809 Hz      95.34%  28571429 Hz    bad     assigned-clocks = <&clk IMX8MM_CLK_ECSPIx_ROOT>
+        * 2517 40 MHz  atmel,sama5d27          atmel,at91rm9200-spi    16400000 Hz      82.00%  82000000 Hz    good    default
+        * 2518 40 MHz  atmel,sama5d27          atmel,at91rm9200-spi    16400000 Hz      82.00%  82000000 Hz    good    default
+        *
+        * Limit SPI clock to 85% of SYSCLOCK / 2 for now.
+        */
+       priv->spi_max_speed_hz_orig = spi->max_speed_hz;
+       spi->max_speed_hz = min(spi->max_speed_hz, freq / 2 / 1000 * 850);
+       spi->bits_per_word = 8;
+       spi->rt = true;
+       err = spi_setup(spi);
+       if (err)
+               goto out_free_candev;
+
+       err = mcp25xxfd_regmap_init(priv);
+       if (err)
+               goto out_free_candev;
+
+       err = can_rx_offload_add_manual(ndev, &priv->offload,
+                                       MCP25XXFD_NAPI_WEIGHT);
+       if (err)
+               goto out_free_candev;
+
+       err = mcp25xxfd_register(priv);
+       if (err)
+               goto out_free_candev;
+
+       return 0;
+
+ out_free_candev:
+       spi->max_speed_hz = priv->spi_max_speed_hz_orig;
+
+       free_candev(ndev);
+
+       return err;
+}
+
+static int mcp25xxfd_remove(struct spi_device *spi)
+{
+       struct mcp25xxfd_priv *priv = spi_get_drvdata(spi);
+       struct net_device *ndev = priv->ndev;
+
+       can_rx_offload_del(&priv->offload);
+       mcp25xxfd_unregister(priv);
+       spi->max_speed_hz = priv->spi_max_speed_hz_orig;
+       free_candev(ndev);
+
+       return 0;
+}
+
+static int __maybe_unused mcp25xxfd_runtime_suspend(struct device *device)
+{
+       const struct mcp25xxfd_priv *priv = dev_get_drvdata(device);
+
+       return mcp25xxfd_clks_and_vdd_disable(priv);
+}
+
+static int __maybe_unused mcp25xxfd_runtime_resume(struct device *device)
+{
+       const struct mcp25xxfd_priv *priv = dev_get_drvdata(device);
+
+       return mcp25xxfd_clks_and_vdd_enable(priv);
+}
+
+static const struct dev_pm_ops mcp25xxfd_pm_ops = {
+       SET_RUNTIME_PM_OPS(mcp25xxfd_runtime_suspend,
+                          mcp25xxfd_runtime_resume, NULL)
+};
+
+static struct spi_driver mcp25xxfd_driver = {
+       .driver = {
+               .name = DEVICE_NAME,
+               .pm = &mcp25xxfd_pm_ops,
+               .of_match_table = mcp25xxfd_of_match,
+       },
+       .probe = mcp25xxfd_probe,
+       .remove = mcp25xxfd_remove,
+       .id_table = mcp25xxfd_id_table,
+};
+module_spi_driver(mcp25xxfd_driver);
+
+MODULE_AUTHOR("Marc Kleine-Budde <mkl@pengutronix.de>");
+MODULE_DESCRIPTION("Microchip MCP25xxFD Family CAN controller driver");
+MODULE_LICENSE("GPL v2");