can: move SPI drivers into a separate directory
authorStefano Babic <sbabic@denx.de>
Tue, 25 Mar 2014 14:30:21 +0000 (15:30 +0100)
committerMarc Kleine-Budde <mkl@pengutronix.de>
Thu, 24 Apr 2014 20:54:16 +0000 (22:54 +0200)
Create a directory for all CAN drivers using SPI and move mcp251x driver there.

Signed-off-by: Stefano Babic <sbabic@denx.de>
Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
drivers/net/can/Kconfig
drivers/net/can/Makefile
drivers/net/can/mcp251x.c [deleted file]
drivers/net/can/spi/Kconfig [new file with mode: 0644]
drivers/net/can/spi/Makefile [new file with mode: 0644]
drivers/net/can/spi/mcp251x.c [new file with mode: 0644]

index 9e7d95d..4aacaa9 100644 (file)
@@ -77,12 +77,6 @@ config CAN_TI_HECC
          Driver for TI HECC (High End CAN Controller) module found on many
          TI devices. The device specifications are available from www.ti.com
 
-config CAN_MCP251X
-       tristate "Microchip MCP251x SPI CAN controllers"
-       depends on SPI && HAS_DMA
-       ---help---
-         Driver for the Microchip MCP251x SPI CAN controllers.
-
 config CAN_BFIN
        depends on BF534 || BF536 || BF537 || BF538 || BF539 || BF54x
        tristate "Analog Devices Blackfin on-chip CAN"
@@ -133,6 +127,8 @@ source "drivers/net/can/c_can/Kconfig"
 
 source "drivers/net/can/cc770/Kconfig"
 
+source "drivers/net/can/spi/Kconfig"
+
 source "drivers/net/can/usb/Kconfig"
 
 source "drivers/net/can/softing/Kconfig"
index c744039..c420588 100644 (file)
@@ -10,6 +10,7 @@ can-dev-y                     := dev.o
 
 can-dev-$(CONFIG_CAN_LEDS)     += led.o
 
+obj-y                          += spi/
 obj-y                          += usb/
 obj-y                          += softing/
 
@@ -19,7 +20,6 @@ obj-$(CONFIG_CAN_C_CAN)               += c_can/
 obj-$(CONFIG_CAN_CC770)                += cc770/
 obj-$(CONFIG_CAN_AT91)         += at91_can.o
 obj-$(CONFIG_CAN_TI_HECC)      += ti_hecc.o
-obj-$(CONFIG_CAN_MCP251X)      += mcp251x.o
 obj-$(CONFIG_CAN_BFIN)         += bfin_can.o
 obj-$(CONFIG_CAN_JANZ_ICAN3)   += janz-ican3.o
 obj-$(CONFIG_CAN_FLEXCAN)      += flexcan.o
diff --git a/drivers/net/can/mcp251x.c b/drivers/net/can/mcp251x.c
deleted file mode 100644 (file)
index bc235f9..0000000
+++ /dev/null
@@ -1,1266 +0,0 @@
-/*
- * CAN bus driver for Microchip 251x CAN Controller with SPI Interface
- *
- * MCP2510 support and bug fixes by Christian Pellegrin
- * <chripell@evolware.org>
- *
- * Copyright 2009 Christian Pellegrin EVOL S.r.l.
- *
- * Copyright 2007 Raymarine UK, Ltd. All Rights Reserved.
- * Written under contract by:
- *   Chris Elston, Katalix Systems, Ltd.
- *
- * Based on Microchip MCP251x CAN controller driver written by
- * David Vrabel, Copyright 2006 Arcom Control Systems Ltd.
- *
- * Based on CAN bus driver for the CCAN controller written by
- * - Sascha Hauer, Marc Kleine-Budde, Pengutronix
- * - Simon Kallweit, intefo AG
- * Copyright 2007
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the version 2 of the GNU General Public License
- * as published by the Free Software Foundation
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, see <http://www.gnu.org/licenses/>.
- *
- *
- *
- * Your platform definition file should specify something like:
- *
- * static struct mcp251x_platform_data mcp251x_info = {
- *         .oscillator_frequency = 8000000,
- * };
- *
- * static struct spi_board_info spi_board_info[] = {
- *         {
- *                 .modalias = "mcp2510",
- *                     // or "mcp2515" depending on your controller
- *                 .platform_data = &mcp251x_info,
- *                 .irq = IRQ_EINT13,
- *                 .max_speed_hz = 2*1000*1000,
- *                 .chip_select = 2,
- *         },
- * };
- *
- * Please see mcp251x.h for a description of the fields in
- * struct mcp251x_platform_data.
- *
- */
-
-#include <linux/can/core.h>
-#include <linux/can/dev.h>
-#include <linux/can/led.h>
-#include <linux/can/platform/mcp251x.h>
-#include <linux/clk.h>
-#include <linux/completion.h>
-#include <linux/delay.h>
-#include <linux/device.h>
-#include <linux/dma-mapping.h>
-#include <linux/freezer.h>
-#include <linux/interrupt.h>
-#include <linux/io.h>
-#include <linux/kernel.h>
-#include <linux/module.h>
-#include <linux/netdevice.h>
-#include <linux/of.h>
-#include <linux/of_device.h>
-#include <linux/platform_device.h>
-#include <linux/slab.h>
-#include <linux/spi/spi.h>
-#include <linux/uaccess.h>
-#include <linux/regulator/consumer.h>
-
-/* SPI interface instruction set */
-#define INSTRUCTION_WRITE      0x02
-#define INSTRUCTION_READ       0x03
-#define INSTRUCTION_BIT_MODIFY 0x05
-#define INSTRUCTION_LOAD_TXB(n)        (0x40 + 2 * (n))
-#define INSTRUCTION_READ_RXB(n)        (((n) == 0) ? 0x90 : 0x94)
-#define INSTRUCTION_RESET      0xC0
-#define RTS_TXB0               0x01
-#define RTS_TXB1               0x02
-#define RTS_TXB2               0x04
-#define INSTRUCTION_RTS(n)     (0x80 | ((n) & 0x07))
-
-
-/* MPC251x registers */
-#define CANSTAT              0x0e
-#define CANCTRL              0x0f
-#  define CANCTRL_REQOP_MASK       0xe0
-#  define CANCTRL_REQOP_CONF       0x80
-#  define CANCTRL_REQOP_LISTEN_ONLY 0x60
-#  define CANCTRL_REQOP_LOOPBACK    0x40
-#  define CANCTRL_REQOP_SLEEP      0x20
-#  define CANCTRL_REQOP_NORMAL     0x00
-#  define CANCTRL_OSM              0x08
-#  define CANCTRL_ABAT             0x10
-#define TEC          0x1c
-#define REC          0x1d
-#define CNF1         0x2a
-#  define CNF1_SJW_SHIFT   6
-#define CNF2         0x29
-#  define CNF2_BTLMODE    0x80
-#  define CNF2_SAM         0x40
-#  define CNF2_PS1_SHIFT   3
-#define CNF3         0x28
-#  define CNF3_SOF        0x08
-#  define CNF3_WAKFIL     0x04
-#  define CNF3_PHSEG2_MASK 0x07
-#define CANINTE              0x2b
-#  define CANINTE_MERRE 0x80
-#  define CANINTE_WAKIE 0x40
-#  define CANINTE_ERRIE 0x20
-#  define CANINTE_TX2IE 0x10
-#  define CANINTE_TX1IE 0x08
-#  define CANINTE_TX0IE 0x04
-#  define CANINTE_RX1IE 0x02
-#  define CANINTE_RX0IE 0x01
-#define CANINTF              0x2c
-#  define CANINTF_MERRF 0x80
-#  define CANINTF_WAKIF 0x40
-#  define CANINTF_ERRIF 0x20
-#  define CANINTF_TX2IF 0x10
-#  define CANINTF_TX1IF 0x08
-#  define CANINTF_TX0IF 0x04
-#  define CANINTF_RX1IF 0x02
-#  define CANINTF_RX0IF 0x01
-#  define CANINTF_RX (CANINTF_RX0IF | CANINTF_RX1IF)
-#  define CANINTF_TX (CANINTF_TX2IF | CANINTF_TX1IF | CANINTF_TX0IF)
-#  define CANINTF_ERR (CANINTF_ERRIF)
-#define EFLG         0x2d
-#  define EFLG_EWARN   0x01
-#  define EFLG_RXWAR   0x02
-#  define EFLG_TXWAR   0x04
-#  define EFLG_RXEP    0x08
-#  define EFLG_TXEP    0x10
-#  define EFLG_TXBO    0x20
-#  define EFLG_RX0OVR  0x40
-#  define EFLG_RX1OVR  0x80
-#define TXBCTRL(n)  (((n) * 0x10) + 0x30 + TXBCTRL_OFF)
-#  define TXBCTRL_ABTF 0x40
-#  define TXBCTRL_MLOA 0x20
-#  define TXBCTRL_TXERR 0x10
-#  define TXBCTRL_TXREQ 0x08
-#define TXBSIDH(n)  (((n) * 0x10) + 0x30 + TXBSIDH_OFF)
-#  define SIDH_SHIFT    3
-#define TXBSIDL(n)  (((n) * 0x10) + 0x30 + TXBSIDL_OFF)
-#  define SIDL_SID_MASK    7
-#  define SIDL_SID_SHIFT   5
-#  define SIDL_EXIDE_SHIFT 3
-#  define SIDL_EID_SHIFT   16
-#  define SIDL_EID_MASK    3
-#define TXBEID8(n)  (((n) * 0x10) + 0x30 + TXBEID8_OFF)
-#define TXBEID0(n)  (((n) * 0x10) + 0x30 + TXBEID0_OFF)
-#define TXBDLC(n)   (((n) * 0x10) + 0x30 + TXBDLC_OFF)
-#  define DLC_RTR_SHIFT    6
-#define TXBCTRL_OFF 0
-#define TXBSIDH_OFF 1
-#define TXBSIDL_OFF 2
-#define TXBEID8_OFF 3
-#define TXBEID0_OFF 4
-#define TXBDLC_OFF  5
-#define TXBDAT_OFF  6
-#define RXBCTRL(n)  (((n) * 0x10) + 0x60 + RXBCTRL_OFF)
-#  define RXBCTRL_BUKT 0x04
-#  define RXBCTRL_RXM0 0x20
-#  define RXBCTRL_RXM1 0x40
-#define RXBSIDH(n)  (((n) * 0x10) + 0x60 + RXBSIDH_OFF)
-#  define RXBSIDH_SHIFT 3
-#define RXBSIDL(n)  (((n) * 0x10) + 0x60 + RXBSIDL_OFF)
-#  define RXBSIDL_IDE   0x08
-#  define RXBSIDL_SRR   0x10
-#  define RXBSIDL_EID   3
-#  define RXBSIDL_SHIFT 5
-#define RXBEID8(n)  (((n) * 0x10) + 0x60 + RXBEID8_OFF)
-#define RXBEID0(n)  (((n) * 0x10) + 0x60 + RXBEID0_OFF)
-#define RXBDLC(n)   (((n) * 0x10) + 0x60 + RXBDLC_OFF)
-#  define RXBDLC_LEN_MASK  0x0f
-#  define RXBDLC_RTR       0x40
-#define RXBCTRL_OFF 0
-#define RXBSIDH_OFF 1
-#define RXBSIDL_OFF 2
-#define RXBEID8_OFF 3
-#define RXBEID0_OFF 4
-#define RXBDLC_OFF  5
-#define RXBDAT_OFF  6
-#define RXFSIDH(n) ((n) * 4)
-#define RXFSIDL(n) ((n) * 4 + 1)
-#define RXFEID8(n) ((n) * 4 + 2)
-#define RXFEID0(n) ((n) * 4 + 3)
-#define RXMSIDH(n) ((n) * 4 + 0x20)
-#define RXMSIDL(n) ((n) * 4 + 0x21)
-#define RXMEID8(n) ((n) * 4 + 0x22)
-#define RXMEID0(n) ((n) * 4 + 0x23)
-
-#define GET_BYTE(val, byte)                    \
-       (((val) >> ((byte) * 8)) & 0xff)
-#define SET_BYTE(val, byte)                    \
-       (((val) & 0xff) << ((byte) * 8))
-
-/*
- * Buffer size required for the largest SPI transfer (i.e., reading a
- * frame)
- */
-#define CAN_FRAME_MAX_DATA_LEN 8
-#define SPI_TRANSFER_BUF_LEN   (6 + CAN_FRAME_MAX_DATA_LEN)
-#define CAN_FRAME_MAX_BITS     128
-
-#define TX_ECHO_SKB_MAX        1
-
-#define MCP251X_OST_DELAY_MS   (5)
-
-#define DEVICE_NAME "mcp251x"
-
-static int mcp251x_enable_dma; /* Enable SPI DMA. Default: 0 (Off) */
-module_param(mcp251x_enable_dma, int, S_IRUGO);
-MODULE_PARM_DESC(mcp251x_enable_dma, "Enable SPI DMA. Default: 0 (Off)");
-
-static const struct can_bittiming_const mcp251x_bittiming_const = {
-       .name = DEVICE_NAME,
-       .tseg1_min = 3,
-       .tseg1_max = 16,
-       .tseg2_min = 2,
-       .tseg2_max = 8,
-       .sjw_max = 4,
-       .brp_min = 1,
-       .brp_max = 64,
-       .brp_inc = 1,
-};
-
-enum mcp251x_model {
-       CAN_MCP251X_MCP2510     = 0x2510,
-       CAN_MCP251X_MCP2515     = 0x2515,
-};
-
-struct mcp251x_priv {
-       struct can_priv    can;
-       struct net_device *net;
-       struct spi_device *spi;
-       enum mcp251x_model model;
-
-       struct mutex mcp_lock; /* SPI device lock */
-
-       u8 *spi_tx_buf;
-       u8 *spi_rx_buf;
-       dma_addr_t spi_tx_dma;
-       dma_addr_t spi_rx_dma;
-
-       struct sk_buff *tx_skb;
-       int tx_len;
-
-       struct workqueue_struct *wq;
-       struct work_struct tx_work;
-       struct work_struct restart_work;
-
-       int force_quit;
-       int after_suspend;
-#define AFTER_SUSPEND_UP 1
-#define AFTER_SUSPEND_DOWN 2
-#define AFTER_SUSPEND_POWER 4
-#define AFTER_SUSPEND_RESTART 8
-       int restart_tx;
-       struct regulator *power;
-       struct regulator *transceiver;
-       struct clk *clk;
-};
-
-#define MCP251X_IS(_model) \
-static inline int mcp251x_is_##_model(struct spi_device *spi) \
-{ \
-       struct mcp251x_priv *priv = spi_get_drvdata(spi); \
-       return priv->model == CAN_MCP251X_MCP##_model; \
-}
-
-MCP251X_IS(2510);
-MCP251X_IS(2515);
-
-static void mcp251x_clean(struct net_device *net)
-{
-       struct mcp251x_priv *priv = netdev_priv(net);
-
-       if (priv->tx_skb || priv->tx_len)
-               net->stats.tx_errors++;
-       if (priv->tx_skb)
-               dev_kfree_skb(priv->tx_skb);
-       if (priv->tx_len)
-               can_free_echo_skb(priv->net, 0);
-       priv->tx_skb = NULL;
-       priv->tx_len = 0;
-}
-
-/*
- * Note about handling of error return of mcp251x_spi_trans: accessing
- * registers via SPI is not really different conceptually than using
- * normal I/O assembler instructions, although it's much more
- * complicated from a practical POV. So it's not advisable to always
- * check the return value of this function. Imagine that every
- * read{b,l}, write{b,l} and friends would be bracketed in "if ( < 0)
- * error();", it would be a great mess (well there are some situation
- * when exception handling C++ like could be useful after all). So we
- * just check that transfers are OK at the beginning of our
- * conversation with the chip and to avoid doing really nasty things
- * (like injecting bogus packets in the network stack).
- */
-static int mcp251x_spi_trans(struct spi_device *spi, int len)
-{
-       struct mcp251x_priv *priv = spi_get_drvdata(spi);
-       struct spi_transfer t = {
-               .tx_buf = priv->spi_tx_buf,
-               .rx_buf = priv->spi_rx_buf,
-               .len = len,
-               .cs_change = 0,
-       };
-       struct spi_message m;
-       int ret;
-
-       spi_message_init(&m);
-
-       if (mcp251x_enable_dma) {
-               t.tx_dma = priv->spi_tx_dma;
-               t.rx_dma = priv->spi_rx_dma;
-               m.is_dma_mapped = 1;
-       }
-
-       spi_message_add_tail(&t, &m);
-
-       ret = spi_sync(spi, &m);
-       if (ret)
-               dev_err(&spi->dev, "spi transfer failed: ret = %d\n", ret);
-       return ret;
-}
-
-static u8 mcp251x_read_reg(struct spi_device *spi, uint8_t reg)
-{
-       struct mcp251x_priv *priv = spi_get_drvdata(spi);
-       u8 val = 0;
-
-       priv->spi_tx_buf[0] = INSTRUCTION_READ;
-       priv->spi_tx_buf[1] = reg;
-
-       mcp251x_spi_trans(spi, 3);
-       val = priv->spi_rx_buf[2];
-
-       return val;
-}
-
-static void mcp251x_read_2regs(struct spi_device *spi, uint8_t reg,
-               uint8_t *v1, uint8_t *v2)
-{
-       struct mcp251x_priv *priv = spi_get_drvdata(spi);
-
-       priv->spi_tx_buf[0] = INSTRUCTION_READ;
-       priv->spi_tx_buf[1] = reg;
-
-       mcp251x_spi_trans(spi, 4);
-
-       *v1 = priv->spi_rx_buf[2];
-       *v2 = priv->spi_rx_buf[3];
-}
-
-static void mcp251x_write_reg(struct spi_device *spi, u8 reg, uint8_t val)
-{
-       struct mcp251x_priv *priv = spi_get_drvdata(spi);
-
-       priv->spi_tx_buf[0] = INSTRUCTION_WRITE;
-       priv->spi_tx_buf[1] = reg;
-       priv->spi_tx_buf[2] = val;
-
-       mcp251x_spi_trans(spi, 3);
-}
-
-static void mcp251x_write_bits(struct spi_device *spi, u8 reg,
-                              u8 mask, uint8_t val)
-{
-       struct mcp251x_priv *priv = spi_get_drvdata(spi);
-
-       priv->spi_tx_buf[0] = INSTRUCTION_BIT_MODIFY;
-       priv->spi_tx_buf[1] = reg;
-       priv->spi_tx_buf[2] = mask;
-       priv->spi_tx_buf[3] = val;
-
-       mcp251x_spi_trans(spi, 4);
-}
-
-static void mcp251x_hw_tx_frame(struct spi_device *spi, u8 *buf,
-                               int len, int tx_buf_idx)
-{
-       struct mcp251x_priv *priv = spi_get_drvdata(spi);
-
-       if (mcp251x_is_2510(spi)) {
-               int i;
-
-               for (i = 1; i < TXBDAT_OFF + len; i++)
-                       mcp251x_write_reg(spi, TXBCTRL(tx_buf_idx) + i,
-                                         buf[i]);
-       } else {
-               memcpy(priv->spi_tx_buf, buf, TXBDAT_OFF + len);
-               mcp251x_spi_trans(spi, TXBDAT_OFF + len);
-       }
-}
-
-static void mcp251x_hw_tx(struct spi_device *spi, struct can_frame *frame,
-                         int tx_buf_idx)
-{
-       struct mcp251x_priv *priv = spi_get_drvdata(spi);
-       u32 sid, eid, exide, rtr;
-       u8 buf[SPI_TRANSFER_BUF_LEN];
-
-       exide = (frame->can_id & CAN_EFF_FLAG) ? 1 : 0; /* Extended ID Enable */
-       if (exide)
-               sid = (frame->can_id & CAN_EFF_MASK) >> 18;
-       else
-               sid = frame->can_id & CAN_SFF_MASK; /* Standard ID */
-       eid = frame->can_id & CAN_EFF_MASK; /* Extended ID */
-       rtr = (frame->can_id & CAN_RTR_FLAG) ? 1 : 0; /* Remote transmission */
-
-       buf[TXBCTRL_OFF] = INSTRUCTION_LOAD_TXB(tx_buf_idx);
-       buf[TXBSIDH_OFF] = sid >> SIDH_SHIFT;
-       buf[TXBSIDL_OFF] = ((sid & SIDL_SID_MASK) << SIDL_SID_SHIFT) |
-               (exide << SIDL_EXIDE_SHIFT) |
-               ((eid >> SIDL_EID_SHIFT) & SIDL_EID_MASK);
-       buf[TXBEID8_OFF] = GET_BYTE(eid, 1);
-       buf[TXBEID0_OFF] = GET_BYTE(eid, 0);
-       buf[TXBDLC_OFF] = (rtr << DLC_RTR_SHIFT) | frame->can_dlc;
-       memcpy(buf + TXBDAT_OFF, frame->data, frame->can_dlc);
-       mcp251x_hw_tx_frame(spi, buf, frame->can_dlc, tx_buf_idx);
-
-       /* use INSTRUCTION_RTS, to avoid "repeated frame problem" */
-       priv->spi_tx_buf[0] = INSTRUCTION_RTS(1 << tx_buf_idx);
-       mcp251x_spi_trans(priv->spi, 1);
-}
-
-static void mcp251x_hw_rx_frame(struct spi_device *spi, u8 *buf,
-                               int buf_idx)
-{
-       struct mcp251x_priv *priv = spi_get_drvdata(spi);
-
-       if (mcp251x_is_2510(spi)) {
-               int i, len;
-
-               for (i = 1; i < RXBDAT_OFF; i++)
-                       buf[i] = mcp251x_read_reg(spi, RXBCTRL(buf_idx) + i);
-
-               len = get_can_dlc(buf[RXBDLC_OFF] & RXBDLC_LEN_MASK);
-               for (; i < (RXBDAT_OFF + len); i++)
-                       buf[i] = mcp251x_read_reg(spi, RXBCTRL(buf_idx) + i);
-       } else {
-               priv->spi_tx_buf[RXBCTRL_OFF] = INSTRUCTION_READ_RXB(buf_idx);
-               mcp251x_spi_trans(spi, SPI_TRANSFER_BUF_LEN);
-               memcpy(buf, priv->spi_rx_buf, SPI_TRANSFER_BUF_LEN);
-       }
-}
-
-static void mcp251x_hw_rx(struct spi_device *spi, int buf_idx)
-{
-       struct mcp251x_priv *priv = spi_get_drvdata(spi);
-       struct sk_buff *skb;
-       struct can_frame *frame;
-       u8 buf[SPI_TRANSFER_BUF_LEN];
-
-       skb = alloc_can_skb(priv->net, &frame);
-       if (!skb) {
-               dev_err(&spi->dev, "cannot allocate RX skb\n");
-               priv->net->stats.rx_dropped++;
-               return;
-       }
-
-       mcp251x_hw_rx_frame(spi, buf, buf_idx);
-       if (buf[RXBSIDL_OFF] & RXBSIDL_IDE) {
-               /* Extended ID format */
-               frame->can_id = CAN_EFF_FLAG;
-               frame->can_id |=
-                       /* Extended ID part */
-                       SET_BYTE(buf[RXBSIDL_OFF] & RXBSIDL_EID, 2) |
-                       SET_BYTE(buf[RXBEID8_OFF], 1) |
-                       SET_BYTE(buf[RXBEID0_OFF], 0) |
-                       /* Standard ID part */
-                       (((buf[RXBSIDH_OFF] << RXBSIDH_SHIFT) |
-                         (buf[RXBSIDL_OFF] >> RXBSIDL_SHIFT)) << 18);
-               /* Remote transmission request */
-               if (buf[RXBDLC_OFF] & RXBDLC_RTR)
-                       frame->can_id |= CAN_RTR_FLAG;
-       } else {
-               /* Standard ID format */
-               frame->can_id =
-                       (buf[RXBSIDH_OFF] << RXBSIDH_SHIFT) |
-                       (buf[RXBSIDL_OFF] >> RXBSIDL_SHIFT);
-               if (buf[RXBSIDL_OFF] & RXBSIDL_SRR)
-                       frame->can_id |= CAN_RTR_FLAG;
-       }
-       /* Data length */
-       frame->can_dlc = get_can_dlc(buf[RXBDLC_OFF] & RXBDLC_LEN_MASK);
-       memcpy(frame->data, buf + RXBDAT_OFF, frame->can_dlc);
-
-       priv->net->stats.rx_packets++;
-       priv->net->stats.rx_bytes += frame->can_dlc;
-
-       can_led_event(priv->net, CAN_LED_EVENT_RX);
-
-       netif_rx_ni(skb);
-}
-
-static void mcp251x_hw_sleep(struct spi_device *spi)
-{
-       mcp251x_write_reg(spi, CANCTRL, CANCTRL_REQOP_SLEEP);
-}
-
-static netdev_tx_t mcp251x_hard_start_xmit(struct sk_buff *skb,
-                                          struct net_device *net)
-{
-       struct mcp251x_priv *priv = netdev_priv(net);
-       struct spi_device *spi = priv->spi;
-
-       if (priv->tx_skb || priv->tx_len) {
-               dev_warn(&spi->dev, "hard_xmit called while tx busy\n");
-               return NETDEV_TX_BUSY;
-       }
-
-       if (can_dropped_invalid_skb(net, skb))
-               return NETDEV_TX_OK;
-
-       netif_stop_queue(net);
-       priv->tx_skb = skb;
-       queue_work(priv->wq, &priv->tx_work);
-
-       return NETDEV_TX_OK;
-}
-
-static int mcp251x_do_set_mode(struct net_device *net, enum can_mode mode)
-{
-       struct mcp251x_priv *priv = netdev_priv(net);
-
-       switch (mode) {
-       case CAN_MODE_START:
-               mcp251x_clean(net);
-               /* We have to delay work since SPI I/O may sleep */
-               priv->can.state = CAN_STATE_ERROR_ACTIVE;
-               priv->restart_tx = 1;
-               if (priv->can.restart_ms == 0)
-                       priv->after_suspend = AFTER_SUSPEND_RESTART;
-               queue_work(priv->wq, &priv->restart_work);
-               break;
-       default:
-               return -EOPNOTSUPP;
-       }
-
-       return 0;
-}
-
-static int mcp251x_set_normal_mode(struct spi_device *spi)
-{
-       struct mcp251x_priv *priv = spi_get_drvdata(spi);
-       unsigned long timeout;
-
-       /* Enable interrupts */
-       mcp251x_write_reg(spi, CANINTE,
-                         CANINTE_ERRIE | CANINTE_TX2IE | CANINTE_TX1IE |
-                         CANINTE_TX0IE | CANINTE_RX1IE | CANINTE_RX0IE);
-
-       if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK) {
-               /* Put device into loopback mode */
-               mcp251x_write_reg(spi, CANCTRL, CANCTRL_REQOP_LOOPBACK);
-       } else if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY) {
-               /* Put device into listen-only mode */
-               mcp251x_write_reg(spi, CANCTRL, CANCTRL_REQOP_LISTEN_ONLY);
-       } else {
-               /* Put device into normal mode */
-               mcp251x_write_reg(spi, CANCTRL, CANCTRL_REQOP_NORMAL);
-
-               /* Wait for the device to enter normal mode */
-               timeout = jiffies + HZ;
-               while (mcp251x_read_reg(spi, CANSTAT) & CANCTRL_REQOP_MASK) {
-                       schedule();
-                       if (time_after(jiffies, timeout)) {
-                               dev_err(&spi->dev, "MCP251x didn't"
-                                       " enter in normal mode\n");
-                               return -EBUSY;
-                       }
-               }
-       }
-       priv->can.state = CAN_STATE_ERROR_ACTIVE;
-       return 0;
-}
-
-static int mcp251x_do_set_bittiming(struct net_device *net)
-{
-       struct mcp251x_priv *priv = netdev_priv(net);
-       struct can_bittiming *bt = &priv->can.bittiming;
-       struct spi_device *spi = priv->spi;
-
-       mcp251x_write_reg(spi, CNF1, ((bt->sjw - 1) << CNF1_SJW_SHIFT) |
-                         (bt->brp - 1));
-       mcp251x_write_reg(spi, CNF2, CNF2_BTLMODE |
-                         (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES ?
-                          CNF2_SAM : 0) |
-                         ((bt->phase_seg1 - 1) << CNF2_PS1_SHIFT) |
-                         (bt->prop_seg - 1));
-       mcp251x_write_bits(spi, CNF3, CNF3_PHSEG2_MASK,
-                          (bt->phase_seg2 - 1));
-       dev_dbg(&spi->dev, "CNF: 0x%02x 0x%02x 0x%02x\n",
-               mcp251x_read_reg(spi, CNF1),
-               mcp251x_read_reg(spi, CNF2),
-               mcp251x_read_reg(spi, CNF3));
-
-       return 0;
-}
-
-static int mcp251x_setup(struct net_device *net, struct mcp251x_priv *priv,
-                        struct spi_device *spi)
-{
-       mcp251x_do_set_bittiming(net);
-
-       mcp251x_write_reg(spi, RXBCTRL(0),
-                         RXBCTRL_BUKT | RXBCTRL_RXM0 | RXBCTRL_RXM1);
-       mcp251x_write_reg(spi, RXBCTRL(1),
-                         RXBCTRL_RXM0 | RXBCTRL_RXM1);
-       return 0;
-}
-
-static int mcp251x_hw_reset(struct spi_device *spi)
-{
-       struct mcp251x_priv *priv = spi_get_drvdata(spi);
-       u8 reg;
-       int ret;
-
-       /* Wait for oscillator startup timer after power up */
-       mdelay(MCP251X_OST_DELAY_MS);
-
-       priv->spi_tx_buf[0] = INSTRUCTION_RESET;
-       ret = mcp251x_spi_trans(spi, 1);
-       if (ret)
-               return ret;
-
-       /* Wait for oscillator startup timer after reset */
-       mdelay(MCP251X_OST_DELAY_MS);
-       
-       reg = mcp251x_read_reg(spi, CANSTAT);
-       if ((reg & CANCTRL_REQOP_MASK) != CANCTRL_REQOP_CONF)
-               return -ENODEV;
-
-       return 0;
-}
-
-static int mcp251x_hw_probe(struct spi_device *spi)
-{
-       u8 ctrl;
-       int ret;
-
-       ret = mcp251x_hw_reset(spi);
-       if (ret)
-               return ret;
-
-       ctrl = mcp251x_read_reg(spi, CANCTRL);
-
-       dev_dbg(&spi->dev, "CANCTRL 0x%02x\n", ctrl);
-
-       /* Check for power up default value */
-       if ((ctrl & 0x17) != 0x07)
-               return -ENODEV;
-
-       return 0;
-}
-
-static int mcp251x_power_enable(struct regulator *reg, int enable)
-{
-       if (IS_ERR_OR_NULL(reg))
-               return 0;
-
-       if (enable)
-               return regulator_enable(reg);
-       else
-               return regulator_disable(reg);
-}
-
-static void mcp251x_open_clean(struct net_device *net)
-{
-       struct mcp251x_priv *priv = netdev_priv(net);
-       struct spi_device *spi = priv->spi;
-
-       free_irq(spi->irq, priv);
-       mcp251x_hw_sleep(spi);
-       mcp251x_power_enable(priv->transceiver, 0);
-       close_candev(net);
-}
-
-static int mcp251x_stop(struct net_device *net)
-{
-       struct mcp251x_priv *priv = netdev_priv(net);
-       struct spi_device *spi = priv->spi;
-
-       close_candev(net);
-
-       priv->force_quit = 1;
-       free_irq(spi->irq, priv);
-       destroy_workqueue(priv->wq);
-       priv->wq = NULL;
-
-       mutex_lock(&priv->mcp_lock);
-
-       /* Disable and clear pending interrupts */
-       mcp251x_write_reg(spi, CANINTE, 0x00);
-       mcp251x_write_reg(spi, CANINTF, 0x00);
-
-       mcp251x_write_reg(spi, TXBCTRL(0), 0);
-       mcp251x_clean(net);
-
-       mcp251x_hw_sleep(spi);
-
-       mcp251x_power_enable(priv->transceiver, 0);
-
-       priv->can.state = CAN_STATE_STOPPED;
-
-       mutex_unlock(&priv->mcp_lock);
-
-       can_led_event(net, CAN_LED_EVENT_STOP);
-
-       return 0;
-}
-
-static void mcp251x_error_skb(struct net_device *net, int can_id, int data1)
-{
-       struct sk_buff *skb;
-       struct can_frame *frame;
-
-       skb = alloc_can_err_skb(net, &frame);
-       if (skb) {
-               frame->can_id |= can_id;
-               frame->data[1] = data1;
-               netif_rx_ni(skb);
-       } else {
-               netdev_err(net, "cannot allocate error skb\n");
-       }
-}
-
-static void mcp251x_tx_work_handler(struct work_struct *ws)
-{
-       struct mcp251x_priv *priv = container_of(ws, struct mcp251x_priv,
-                                                tx_work);
-       struct spi_device *spi = priv->spi;
-       struct net_device *net = priv->net;
-       struct can_frame *frame;
-
-       mutex_lock(&priv->mcp_lock);
-       if (priv->tx_skb) {
-               if (priv->can.state == CAN_STATE_BUS_OFF) {
-                       mcp251x_clean(net);
-               } else {
-                       frame = (struct can_frame *)priv->tx_skb->data;
-
-                       if (frame->can_dlc > CAN_FRAME_MAX_DATA_LEN)
-                               frame->can_dlc = CAN_FRAME_MAX_DATA_LEN;
-                       mcp251x_hw_tx(spi, frame, 0);
-                       priv->tx_len = 1 + frame->can_dlc;
-                       can_put_echo_skb(priv->tx_skb, net, 0);
-                       priv->tx_skb = NULL;
-               }
-       }
-       mutex_unlock(&priv->mcp_lock);
-}
-
-static void mcp251x_restart_work_handler(struct work_struct *ws)
-{
-       struct mcp251x_priv *priv = container_of(ws, struct mcp251x_priv,
-                                                restart_work);
-       struct spi_device *spi = priv->spi;
-       struct net_device *net = priv->net;
-
-       mutex_lock(&priv->mcp_lock);
-       if (priv->after_suspend) {
-               mcp251x_hw_reset(spi);
-               mcp251x_setup(net, priv, spi);
-               if (priv->after_suspend & AFTER_SUSPEND_RESTART) {
-                       mcp251x_set_normal_mode(spi);
-               } else if (priv->after_suspend & AFTER_SUSPEND_UP) {
-                       netif_device_attach(net);
-                       mcp251x_clean(net);
-                       mcp251x_set_normal_mode(spi);
-                       netif_wake_queue(net);
-               } else {
-                       mcp251x_hw_sleep(spi);
-               }
-               priv->after_suspend = 0;
-               priv->force_quit = 0;
-       }
-
-       if (priv->restart_tx) {
-               priv->restart_tx = 0;
-               mcp251x_write_reg(spi, TXBCTRL(0), 0);
-               mcp251x_clean(net);
-               netif_wake_queue(net);
-               mcp251x_error_skb(net, CAN_ERR_RESTARTED, 0);
-       }
-       mutex_unlock(&priv->mcp_lock);
-}
-
-static irqreturn_t mcp251x_can_ist(int irq, void *dev_id)
-{
-       struct mcp251x_priv *priv = dev_id;
-       struct spi_device *spi = priv->spi;
-       struct net_device *net = priv->net;
-
-       mutex_lock(&priv->mcp_lock);
-       while (!priv->force_quit) {
-               enum can_state new_state;
-               u8 intf, eflag;
-               u8 clear_intf = 0;
-               int can_id = 0, data1 = 0;
-
-               mcp251x_read_2regs(spi, CANINTF, &intf, &eflag);
-
-               /* mask out flags we don't care about */
-               intf &= CANINTF_RX | CANINTF_TX | CANINTF_ERR;
-
-               /* receive buffer 0 */
-               if (intf & CANINTF_RX0IF) {
-                       mcp251x_hw_rx(spi, 0);
-                       /*
-                        * Free one buffer ASAP
-                        * (The MCP2515 does this automatically.)
-                        */
-                       if (mcp251x_is_2510(spi))
-                               mcp251x_write_bits(spi, CANINTF, CANINTF_RX0IF, 0x00);
-               }
-
-               /* receive buffer 1 */
-               if (intf & CANINTF_RX1IF) {
-                       mcp251x_hw_rx(spi, 1);
-                       /* the MCP2515 does this automatically */
-                       if (mcp251x_is_2510(spi))
-                               clear_intf |= CANINTF_RX1IF;
-               }
-
-               /* any error or tx interrupt we need to clear? */
-               if (intf & (CANINTF_ERR | CANINTF_TX))
-                       clear_intf |= intf & (CANINTF_ERR | CANINTF_TX);
-               if (clear_intf)
-                       mcp251x_write_bits(spi, CANINTF, clear_intf, 0x00);
-
-               if (eflag)
-                       mcp251x_write_bits(spi, EFLG, eflag, 0x00);
-
-               /* Update can state */
-               if (eflag & EFLG_TXBO) {
-                       new_state = CAN_STATE_BUS_OFF;
-                       can_id |= CAN_ERR_BUSOFF;
-               } else if (eflag & EFLG_TXEP) {
-                       new_state = CAN_STATE_ERROR_PASSIVE;
-                       can_id |= CAN_ERR_CRTL;
-                       data1 |= CAN_ERR_CRTL_TX_PASSIVE;
-               } else if (eflag & EFLG_RXEP) {
-                       new_state = CAN_STATE_ERROR_PASSIVE;
-                       can_id |= CAN_ERR_CRTL;
-                       data1 |= CAN_ERR_CRTL_RX_PASSIVE;
-               } else if (eflag & EFLG_TXWAR) {
-                       new_state = CAN_STATE_ERROR_WARNING;
-                       can_id |= CAN_ERR_CRTL;
-                       data1 |= CAN_ERR_CRTL_TX_WARNING;
-               } else if (eflag & EFLG_RXWAR) {
-                       new_state = CAN_STATE_ERROR_WARNING;
-                       can_id |= CAN_ERR_CRTL;
-                       data1 |= CAN_ERR_CRTL_RX_WARNING;
-               } else {
-                       new_state = CAN_STATE_ERROR_ACTIVE;
-               }
-
-               /* Update can state statistics */
-               switch (priv->can.state) {
-               case CAN_STATE_ERROR_ACTIVE:
-                       if (new_state >= CAN_STATE_ERROR_WARNING &&
-                           new_state <= CAN_STATE_BUS_OFF)
-                               priv->can.can_stats.error_warning++;
-               case CAN_STATE_ERROR_WARNING:   /* fallthrough */
-                       if (new_state >= CAN_STATE_ERROR_PASSIVE &&
-                           new_state <= CAN_STATE_BUS_OFF)
-                               priv->can.can_stats.error_passive++;
-                       break;
-               default:
-                       break;
-               }
-               priv->can.state = new_state;
-
-               if (intf & CANINTF_ERRIF) {
-                       /* Handle overflow counters */
-                       if (eflag & (EFLG_RX0OVR | EFLG_RX1OVR)) {
-                               if (eflag & EFLG_RX0OVR) {
-                                       net->stats.rx_over_errors++;
-                                       net->stats.rx_errors++;
-                               }
-                               if (eflag & EFLG_RX1OVR) {
-                                       net->stats.rx_over_errors++;
-                                       net->stats.rx_errors++;
-                               }
-                               can_id |= CAN_ERR_CRTL;
-                               data1 |= CAN_ERR_CRTL_RX_OVERFLOW;
-                       }
-                       mcp251x_error_skb(net, can_id, data1);
-               }
-
-               if (priv->can.state == CAN_STATE_BUS_OFF) {
-                       if (priv->can.restart_ms == 0) {
-                               priv->force_quit = 1;
-                               can_bus_off(net);
-                               mcp251x_hw_sleep(spi);
-                               break;
-                       }
-               }
-
-               if (intf == 0)
-                       break;
-
-               if (intf & CANINTF_TX) {
-                       net->stats.tx_packets++;
-                       net->stats.tx_bytes += priv->tx_len - 1;
-                       can_led_event(net, CAN_LED_EVENT_TX);
-                       if (priv->tx_len) {
-                               can_get_echo_skb(net, 0);
-                               priv->tx_len = 0;
-                       }
-                       netif_wake_queue(net);
-               }
-
-       }
-       mutex_unlock(&priv->mcp_lock);
-       return IRQ_HANDLED;
-}
-
-static int mcp251x_open(struct net_device *net)
-{
-       struct mcp251x_priv *priv = netdev_priv(net);
-       struct spi_device *spi = priv->spi;
-       unsigned long flags = IRQF_ONESHOT | IRQF_TRIGGER_FALLING;
-       int ret;
-
-       ret = open_candev(net);
-       if (ret) {
-               dev_err(&spi->dev, "unable to set initial baudrate!\n");
-               return ret;
-       }
-
-       mutex_lock(&priv->mcp_lock);
-       mcp251x_power_enable(priv->transceiver, 1);
-
-       priv->force_quit = 0;
-       priv->tx_skb = NULL;
-       priv->tx_len = 0;
-
-       ret = request_threaded_irq(spi->irq, NULL, mcp251x_can_ist,
-                                  flags, DEVICE_NAME, priv);
-       if (ret) {
-               dev_err(&spi->dev, "failed to acquire irq %d\n", spi->irq);
-               mcp251x_power_enable(priv->transceiver, 0);
-               close_candev(net);
-               goto open_unlock;
-       }
-
-       priv->wq = create_freezable_workqueue("mcp251x_wq");
-       INIT_WORK(&priv->tx_work, mcp251x_tx_work_handler);
-       INIT_WORK(&priv->restart_work, mcp251x_restart_work_handler);
-
-       ret = mcp251x_hw_reset(spi);
-       if (ret) {
-               mcp251x_open_clean(net);
-               goto open_unlock;
-       }
-       ret = mcp251x_setup(net, priv, spi);
-       if (ret) {
-               mcp251x_open_clean(net);
-               goto open_unlock;
-       }
-       ret = mcp251x_set_normal_mode(spi);
-       if (ret) {
-               mcp251x_open_clean(net);
-               goto open_unlock;
-       }
-
-       can_led_event(net, CAN_LED_EVENT_OPEN);
-
-       netif_wake_queue(net);
-
-open_unlock:
-       mutex_unlock(&priv->mcp_lock);
-       return ret;
-}
-
-static const struct net_device_ops mcp251x_netdev_ops = {
-       .ndo_open = mcp251x_open,
-       .ndo_stop = mcp251x_stop,
-       .ndo_start_xmit = mcp251x_hard_start_xmit,
-       .ndo_change_mtu = can_change_mtu,
-};
-
-static const struct of_device_id mcp251x_of_match[] = {
-       {
-               .compatible     = "microchip,mcp2510",
-               .data           = (void *)CAN_MCP251X_MCP2510,
-       },
-       {
-               .compatible     = "microchip,mcp2515",
-               .data           = (void *)CAN_MCP251X_MCP2515,
-       },
-       { }
-};
-MODULE_DEVICE_TABLE(of, mcp251x_of_match);
-
-static const struct spi_device_id mcp251x_id_table[] = {
-       {
-               .name           = "mcp2510",
-               .driver_data    = (kernel_ulong_t)CAN_MCP251X_MCP2510,
-       },
-       {
-               .name           = "mcp2515",
-               .driver_data    = (kernel_ulong_t)CAN_MCP251X_MCP2515,
-       },
-       { }
-};
-MODULE_DEVICE_TABLE(spi, mcp251x_id_table);
-
-static int mcp251x_can_probe(struct spi_device *spi)
-{
-       const struct of_device_id *of_id = of_match_device(mcp251x_of_match,
-                                                          &spi->dev);
-       struct mcp251x_platform_data *pdata = dev_get_platdata(&spi->dev);
-       struct net_device *net;
-       struct mcp251x_priv *priv;
-       struct clk *clk;
-       int freq, ret;
-
-       clk = devm_clk_get(&spi->dev, NULL);
-       if (IS_ERR(clk)) {
-               if (pdata)
-                       freq = pdata->oscillator_frequency;
-               else
-                       return PTR_ERR(clk);
-       } else {
-               freq = clk_get_rate(clk);
-       }
-
-       /* Sanity check */
-       if (freq < 1000000 || freq > 25000000)
-               return -ERANGE;
-
-       /* Allocate can/net device */
-       net = alloc_candev(sizeof(struct mcp251x_priv), TX_ECHO_SKB_MAX);
-       if (!net)
-               return -ENOMEM;
-
-       if (!IS_ERR(clk)) {
-               ret = clk_prepare_enable(clk);
-               if (ret)
-                       goto out_free;
-       }
-
-       net->netdev_ops = &mcp251x_netdev_ops;
-       net->flags |= IFF_ECHO;
-
-       priv = netdev_priv(net);
-       priv->can.bittiming_const = &mcp251x_bittiming_const;
-       priv->can.do_set_mode = mcp251x_do_set_mode;
-       priv->can.clock.freq = freq / 2;
-       priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES |
-               CAN_CTRLMODE_LOOPBACK | CAN_CTRLMODE_LISTENONLY;
-       if (of_id)
-               priv->model = (enum mcp251x_model)of_id->data;
-       else
-               priv->model = spi_get_device_id(spi)->driver_data;
-       priv->net = net;
-       priv->clk = clk;
-
-       spi_set_drvdata(spi, priv);
-
-       /* Configure the SPI bus */
-       spi->bits_per_word = 8;
-       if (mcp251x_is_2510(spi))
-               spi->max_speed_hz = spi->max_speed_hz ? : 5 * 1000 * 1000;
-       else
-               spi->max_speed_hz = spi->max_speed_hz ? : 10 * 1000 * 1000;
-       ret = spi_setup(spi);
-       if (ret)
-               goto out_clk;
-
-       priv->power = devm_regulator_get(&spi->dev, "vdd");
-       priv->transceiver = devm_regulator_get(&spi->dev, "xceiver");
-       if ((PTR_ERR(priv->power) == -EPROBE_DEFER) ||
-           (PTR_ERR(priv->transceiver) == -EPROBE_DEFER)) {
-               ret = -EPROBE_DEFER;
-               goto out_clk;
-       }
-
-       ret = mcp251x_power_enable(priv->power, 1);
-       if (ret)
-               goto out_clk;
-
-       priv->spi = spi;
-       mutex_init(&priv->mcp_lock);
-
-       /* If requested, allocate DMA buffers */
-       if (mcp251x_enable_dma) {
-               spi->dev.coherent_dma_mask = ~0;
-
-               /*
-                * Minimum coherent DMA allocation is PAGE_SIZE, so allocate
-                * that much and share it between Tx and Rx DMA buffers.
-                */
-               priv->spi_tx_buf = dma_alloc_coherent(&spi->dev,
-                                                     PAGE_SIZE,
-                                                     &priv->spi_tx_dma,
-                                                     GFP_DMA);
-
-               if (priv->spi_tx_buf) {
-                       priv->spi_rx_buf = (priv->spi_tx_buf + (PAGE_SIZE / 2));
-                       priv->spi_rx_dma = (dma_addr_t)(priv->spi_tx_dma +
-                                                       (PAGE_SIZE / 2));
-               } else {
-                       /* Fall back to non-DMA */
-                       mcp251x_enable_dma = 0;
-               }
-       }
-
-       /* Allocate non-DMA buffers */
-       if (!mcp251x_enable_dma) {
-               priv->spi_tx_buf = devm_kzalloc(&spi->dev, SPI_TRANSFER_BUF_LEN,
-                                               GFP_KERNEL);
-               if (!priv->spi_tx_buf) {
-                       ret = -ENOMEM;
-                       goto error_probe;
-               }
-               priv->spi_rx_buf = devm_kzalloc(&spi->dev, SPI_TRANSFER_BUF_LEN,
-                                               GFP_KERNEL);
-               if (!priv->spi_rx_buf) {
-                       ret = -ENOMEM;
-                       goto error_probe;
-               }
-       }
-
-       SET_NETDEV_DEV(net, &spi->dev);
-
-       /* Here is OK to not lock the MCP, no one knows about it yet */
-       ret = mcp251x_hw_probe(spi);
-       if (ret)
-               goto error_probe;
-
-       mcp251x_hw_sleep(spi);
-
-       ret = register_candev(net);
-       if (ret)
-               goto error_probe;
-
-       devm_can_led_init(net);
-
-       return 0;
-
-error_probe:
-       if (mcp251x_enable_dma)
-               dma_free_coherent(&spi->dev, PAGE_SIZE,
-                                 priv->spi_tx_buf, priv->spi_tx_dma);
-       mcp251x_power_enable(priv->power, 0);
-
-out_clk:
-       if (!IS_ERR(clk))
-               clk_disable_unprepare(clk);
-
-out_free:
-       free_candev(net);
-
-       return ret;
-}
-
-static int mcp251x_can_remove(struct spi_device *spi)
-{
-       struct mcp251x_priv *priv = spi_get_drvdata(spi);
-       struct net_device *net = priv->net;
-
-       unregister_candev(net);
-
-       if (mcp251x_enable_dma) {
-               dma_free_coherent(&spi->dev, PAGE_SIZE,
-                                 priv->spi_tx_buf, priv->spi_tx_dma);
-       }
-
-       mcp251x_power_enable(priv->power, 0);
-
-       if (!IS_ERR(priv->clk))
-               clk_disable_unprepare(priv->clk);
-
-       free_candev(net);
-
-       return 0;
-}
-
-static int __maybe_unused mcp251x_can_suspend(struct device *dev)
-{
-       struct spi_device *spi = to_spi_device(dev);
-       struct mcp251x_priv *priv = spi_get_drvdata(spi);
-       struct net_device *net = priv->net;
-
-       priv->force_quit = 1;
-       disable_irq(spi->irq);
-       /*
-        * Note: at this point neither IST nor workqueues are running.
-        * open/stop cannot be called anyway so locking is not needed
-        */
-       if (netif_running(net)) {
-               netif_device_detach(net);
-
-               mcp251x_hw_sleep(spi);
-               mcp251x_power_enable(priv->transceiver, 0);
-               priv->after_suspend = AFTER_SUSPEND_UP;
-       } else {
-               priv->after_suspend = AFTER_SUSPEND_DOWN;
-       }
-
-       if (!IS_ERR_OR_NULL(priv->power)) {
-               regulator_disable(priv->power);
-               priv->after_suspend |= AFTER_SUSPEND_POWER;
-       }
-
-       return 0;
-}
-
-static int __maybe_unused mcp251x_can_resume(struct device *dev)
-{
-       struct spi_device *spi = to_spi_device(dev);
-       struct mcp251x_priv *priv = spi_get_drvdata(spi);
-
-       if (priv->after_suspend & AFTER_SUSPEND_POWER) {
-               mcp251x_power_enable(priv->power, 1);
-               queue_work(priv->wq, &priv->restart_work);
-       } else {
-               if (priv->after_suspend & AFTER_SUSPEND_UP) {
-                       mcp251x_power_enable(priv->transceiver, 1);
-                       queue_work(priv->wq, &priv->restart_work);
-               } else {
-                       priv->after_suspend = 0;
-               }
-       }
-       priv->force_quit = 0;
-       enable_irq(spi->irq);
-       return 0;
-}
-
-static SIMPLE_DEV_PM_OPS(mcp251x_can_pm_ops, mcp251x_can_suspend,
-       mcp251x_can_resume);
-
-static struct spi_driver mcp251x_can_driver = {
-       .driver = {
-               .name = DEVICE_NAME,
-               .owner = THIS_MODULE,
-               .of_match_table = mcp251x_of_match,
-               .pm = &mcp251x_can_pm_ops,
-       },
-       .id_table = mcp251x_id_table,
-       .probe = mcp251x_can_probe,
-       .remove = mcp251x_can_remove,
-};
-module_spi_driver(mcp251x_can_driver);
-
-MODULE_AUTHOR("Chris Elston <celston@katalix.com>, "
-             "Christian Pellegrin <chripell@evolware.org>");
-MODULE_DESCRIPTION("Microchip 251x CAN driver");
-MODULE_LICENSE("GPL v2");
diff --git a/drivers/net/can/spi/Kconfig b/drivers/net/can/spi/Kconfig
new file mode 100644 (file)
index 0000000..148cae5
--- /dev/null
@@ -0,0 +1,10 @@
+menu "CAN SPI interfaces"
+       depends on SPI
+
+config CAN_MCP251X
+       tristate "Microchip MCP251x SPI CAN controllers"
+       depends on HAS_DMA
+       ---help---
+         Driver for the Microchip MCP251x SPI CAN controllers.
+
+endmenu
diff --git a/drivers/net/can/spi/Makefile b/drivers/net/can/spi/Makefile
new file mode 100644 (file)
index 0000000..90bcacf
--- /dev/null
@@ -0,0 +1,8 @@
+#
+#  Makefile for the Linux Controller Area Network SPI drivers.
+#
+
+
+obj-$(CONFIG_CAN_MCP251X)      += mcp251x.o
+
+ccflags-$(CONFIG_CAN_DEBUG_DEVICES) := -DDEBUG
diff --git a/drivers/net/can/spi/mcp251x.c b/drivers/net/can/spi/mcp251x.c
new file mode 100644 (file)
index 0000000..bc235f9
--- /dev/null
@@ -0,0 +1,1266 @@
+/*
+ * CAN bus driver for Microchip 251x CAN Controller with SPI Interface
+ *
+ * MCP2510 support and bug fixes by Christian Pellegrin
+ * <chripell@evolware.org>
+ *
+ * Copyright 2009 Christian Pellegrin EVOL S.r.l.
+ *
+ * Copyright 2007 Raymarine UK, Ltd. All Rights Reserved.
+ * Written under contract by:
+ *   Chris Elston, Katalix Systems, Ltd.
+ *
+ * Based on Microchip MCP251x CAN controller driver written by
+ * David Vrabel, Copyright 2006 Arcom Control Systems Ltd.
+ *
+ * Based on CAN bus driver for the CCAN controller written by
+ * - Sascha Hauer, Marc Kleine-Budde, Pengutronix
+ * - Simon Kallweit, intefo AG
+ * Copyright 2007
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the version 2 of the GNU General Public License
+ * as published by the Free Software Foundation
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <http://www.gnu.org/licenses/>.
+ *
+ *
+ *
+ * Your platform definition file should specify something like:
+ *
+ * static struct mcp251x_platform_data mcp251x_info = {
+ *         .oscillator_frequency = 8000000,
+ * };
+ *
+ * static struct spi_board_info spi_board_info[] = {
+ *         {
+ *                 .modalias = "mcp2510",
+ *                     // or "mcp2515" depending on your controller
+ *                 .platform_data = &mcp251x_info,
+ *                 .irq = IRQ_EINT13,
+ *                 .max_speed_hz = 2*1000*1000,
+ *                 .chip_select = 2,
+ *         },
+ * };
+ *
+ * Please see mcp251x.h for a description of the fields in
+ * struct mcp251x_platform_data.
+ *
+ */
+
+#include <linux/can/core.h>
+#include <linux/can/dev.h>
+#include <linux/can/led.h>
+#include <linux/can/platform/mcp251x.h>
+#include <linux/clk.h>
+#include <linux/completion.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/dma-mapping.h>
+#include <linux/freezer.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/netdevice.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/spi/spi.h>
+#include <linux/uaccess.h>
+#include <linux/regulator/consumer.h>
+
+/* SPI interface instruction set */
+#define INSTRUCTION_WRITE      0x02
+#define INSTRUCTION_READ       0x03
+#define INSTRUCTION_BIT_MODIFY 0x05
+#define INSTRUCTION_LOAD_TXB(n)        (0x40 + 2 * (n))
+#define INSTRUCTION_READ_RXB(n)        (((n) == 0) ? 0x90 : 0x94)
+#define INSTRUCTION_RESET      0xC0
+#define RTS_TXB0               0x01
+#define RTS_TXB1               0x02
+#define RTS_TXB2               0x04
+#define INSTRUCTION_RTS(n)     (0x80 | ((n) & 0x07))
+
+
+/* MPC251x registers */
+#define CANSTAT              0x0e
+#define CANCTRL              0x0f
+#  define CANCTRL_REQOP_MASK       0xe0
+#  define CANCTRL_REQOP_CONF       0x80
+#  define CANCTRL_REQOP_LISTEN_ONLY 0x60
+#  define CANCTRL_REQOP_LOOPBACK    0x40
+#  define CANCTRL_REQOP_SLEEP      0x20
+#  define CANCTRL_REQOP_NORMAL     0x00
+#  define CANCTRL_OSM              0x08
+#  define CANCTRL_ABAT             0x10
+#define TEC          0x1c
+#define REC          0x1d
+#define CNF1         0x2a
+#  define CNF1_SJW_SHIFT   6
+#define CNF2         0x29
+#  define CNF2_BTLMODE    0x80
+#  define CNF2_SAM         0x40
+#  define CNF2_PS1_SHIFT   3
+#define CNF3         0x28
+#  define CNF3_SOF        0x08
+#  define CNF3_WAKFIL     0x04
+#  define CNF3_PHSEG2_MASK 0x07
+#define CANINTE              0x2b
+#  define CANINTE_MERRE 0x80
+#  define CANINTE_WAKIE 0x40
+#  define CANINTE_ERRIE 0x20
+#  define CANINTE_TX2IE 0x10
+#  define CANINTE_TX1IE 0x08
+#  define CANINTE_TX0IE 0x04
+#  define CANINTE_RX1IE 0x02
+#  define CANINTE_RX0IE 0x01
+#define CANINTF              0x2c
+#  define CANINTF_MERRF 0x80
+#  define CANINTF_WAKIF 0x40
+#  define CANINTF_ERRIF 0x20
+#  define CANINTF_TX2IF 0x10
+#  define CANINTF_TX1IF 0x08
+#  define CANINTF_TX0IF 0x04
+#  define CANINTF_RX1IF 0x02
+#  define CANINTF_RX0IF 0x01
+#  define CANINTF_RX (CANINTF_RX0IF | CANINTF_RX1IF)
+#  define CANINTF_TX (CANINTF_TX2IF | CANINTF_TX1IF | CANINTF_TX0IF)
+#  define CANINTF_ERR (CANINTF_ERRIF)
+#define EFLG         0x2d
+#  define EFLG_EWARN   0x01
+#  define EFLG_RXWAR   0x02
+#  define EFLG_TXWAR   0x04
+#  define EFLG_RXEP    0x08
+#  define EFLG_TXEP    0x10
+#  define EFLG_TXBO    0x20
+#  define EFLG_RX0OVR  0x40
+#  define EFLG_RX1OVR  0x80
+#define TXBCTRL(n)  (((n) * 0x10) + 0x30 + TXBCTRL_OFF)
+#  define TXBCTRL_ABTF 0x40
+#  define TXBCTRL_MLOA 0x20
+#  define TXBCTRL_TXERR 0x10
+#  define TXBCTRL_TXREQ 0x08
+#define TXBSIDH(n)  (((n) * 0x10) + 0x30 + TXBSIDH_OFF)
+#  define SIDH_SHIFT    3
+#define TXBSIDL(n)  (((n) * 0x10) + 0x30 + TXBSIDL_OFF)
+#  define SIDL_SID_MASK    7
+#  define SIDL_SID_SHIFT   5
+#  define SIDL_EXIDE_SHIFT 3
+#  define SIDL_EID_SHIFT   16
+#  define SIDL_EID_MASK    3
+#define TXBEID8(n)  (((n) * 0x10) + 0x30 + TXBEID8_OFF)
+#define TXBEID0(n)  (((n) * 0x10) + 0x30 + TXBEID0_OFF)
+#define TXBDLC(n)   (((n) * 0x10) + 0x30 + TXBDLC_OFF)
+#  define DLC_RTR_SHIFT    6
+#define TXBCTRL_OFF 0
+#define TXBSIDH_OFF 1
+#define TXBSIDL_OFF 2
+#define TXBEID8_OFF 3
+#define TXBEID0_OFF 4
+#define TXBDLC_OFF  5
+#define TXBDAT_OFF  6
+#define RXBCTRL(n)  (((n) * 0x10) + 0x60 + RXBCTRL_OFF)
+#  define RXBCTRL_BUKT 0x04
+#  define RXBCTRL_RXM0 0x20
+#  define RXBCTRL_RXM1 0x40
+#define RXBSIDH(n)  (((n) * 0x10) + 0x60 + RXBSIDH_OFF)
+#  define RXBSIDH_SHIFT 3
+#define RXBSIDL(n)  (((n) * 0x10) + 0x60 + RXBSIDL_OFF)
+#  define RXBSIDL_IDE   0x08
+#  define RXBSIDL_SRR   0x10
+#  define RXBSIDL_EID   3
+#  define RXBSIDL_SHIFT 5
+#define RXBEID8(n)  (((n) * 0x10) + 0x60 + RXBEID8_OFF)
+#define RXBEID0(n)  (((n) * 0x10) + 0x60 + RXBEID0_OFF)
+#define RXBDLC(n)   (((n) * 0x10) + 0x60 + RXBDLC_OFF)
+#  define RXBDLC_LEN_MASK  0x0f
+#  define RXBDLC_RTR       0x40
+#define RXBCTRL_OFF 0
+#define RXBSIDH_OFF 1
+#define RXBSIDL_OFF 2
+#define RXBEID8_OFF 3
+#define RXBEID0_OFF 4
+#define RXBDLC_OFF  5
+#define RXBDAT_OFF  6
+#define RXFSIDH(n) ((n) * 4)
+#define RXFSIDL(n) ((n) * 4 + 1)
+#define RXFEID8(n) ((n) * 4 + 2)
+#define RXFEID0(n) ((n) * 4 + 3)
+#define RXMSIDH(n) ((n) * 4 + 0x20)
+#define RXMSIDL(n) ((n) * 4 + 0x21)
+#define RXMEID8(n) ((n) * 4 + 0x22)
+#define RXMEID0(n) ((n) * 4 + 0x23)
+
+#define GET_BYTE(val, byte)                    \
+       (((val) >> ((byte) * 8)) & 0xff)
+#define SET_BYTE(val, byte)                    \
+       (((val) & 0xff) << ((byte) * 8))
+
+/*
+ * Buffer size required for the largest SPI transfer (i.e., reading a
+ * frame)
+ */
+#define CAN_FRAME_MAX_DATA_LEN 8
+#define SPI_TRANSFER_BUF_LEN   (6 + CAN_FRAME_MAX_DATA_LEN)
+#define CAN_FRAME_MAX_BITS     128
+
+#define TX_ECHO_SKB_MAX        1
+
+#define MCP251X_OST_DELAY_MS   (5)
+
+#define DEVICE_NAME "mcp251x"
+
+static int mcp251x_enable_dma; /* Enable SPI DMA. Default: 0 (Off) */
+module_param(mcp251x_enable_dma, int, S_IRUGO);
+MODULE_PARM_DESC(mcp251x_enable_dma, "Enable SPI DMA. Default: 0 (Off)");
+
+static const struct can_bittiming_const mcp251x_bittiming_const = {
+       .name = DEVICE_NAME,
+       .tseg1_min = 3,
+       .tseg1_max = 16,
+       .tseg2_min = 2,
+       .tseg2_max = 8,
+       .sjw_max = 4,
+       .brp_min = 1,
+       .brp_max = 64,
+       .brp_inc = 1,
+};
+
+enum mcp251x_model {
+       CAN_MCP251X_MCP2510     = 0x2510,
+       CAN_MCP251X_MCP2515     = 0x2515,
+};
+
+struct mcp251x_priv {
+       struct can_priv    can;
+       struct net_device *net;
+       struct spi_device *spi;
+       enum mcp251x_model model;
+
+       struct mutex mcp_lock; /* SPI device lock */
+
+       u8 *spi_tx_buf;
+       u8 *spi_rx_buf;
+       dma_addr_t spi_tx_dma;
+       dma_addr_t spi_rx_dma;
+
+       struct sk_buff *tx_skb;
+       int tx_len;
+
+       struct workqueue_struct *wq;
+       struct work_struct tx_work;
+       struct work_struct restart_work;
+
+       int force_quit;
+       int after_suspend;
+#define AFTER_SUSPEND_UP 1
+#define AFTER_SUSPEND_DOWN 2
+#define AFTER_SUSPEND_POWER 4
+#define AFTER_SUSPEND_RESTART 8
+       int restart_tx;
+       struct regulator *power;
+       struct regulator *transceiver;
+       struct clk *clk;
+};
+
+#define MCP251X_IS(_model) \
+static inline int mcp251x_is_##_model(struct spi_device *spi) \
+{ \
+       struct mcp251x_priv *priv = spi_get_drvdata(spi); \
+       return priv->model == CAN_MCP251X_MCP##_model; \
+}
+
+MCP251X_IS(2510);
+MCP251X_IS(2515);
+
+static void mcp251x_clean(struct net_device *net)
+{
+       struct mcp251x_priv *priv = netdev_priv(net);
+
+       if (priv->tx_skb || priv->tx_len)
+               net->stats.tx_errors++;
+       if (priv->tx_skb)
+               dev_kfree_skb(priv->tx_skb);
+       if (priv->tx_len)
+               can_free_echo_skb(priv->net, 0);
+       priv->tx_skb = NULL;
+       priv->tx_len = 0;
+}
+
+/*
+ * Note about handling of error return of mcp251x_spi_trans: accessing
+ * registers via SPI is not really different conceptually than using
+ * normal I/O assembler instructions, although it's much more
+ * complicated from a practical POV. So it's not advisable to always
+ * check the return value of this function. Imagine that every
+ * read{b,l}, write{b,l} and friends would be bracketed in "if ( < 0)
+ * error();", it would be a great mess (well there are some situation
+ * when exception handling C++ like could be useful after all). So we
+ * just check that transfers are OK at the beginning of our
+ * conversation with the chip and to avoid doing really nasty things
+ * (like injecting bogus packets in the network stack).
+ */
+static int mcp251x_spi_trans(struct spi_device *spi, int len)
+{
+       struct mcp251x_priv *priv = spi_get_drvdata(spi);
+       struct spi_transfer t = {
+               .tx_buf = priv->spi_tx_buf,
+               .rx_buf = priv->spi_rx_buf,
+               .len = len,
+               .cs_change = 0,
+       };
+       struct spi_message m;
+       int ret;
+
+       spi_message_init(&m);
+
+       if (mcp251x_enable_dma) {
+               t.tx_dma = priv->spi_tx_dma;
+               t.rx_dma = priv->spi_rx_dma;
+               m.is_dma_mapped = 1;
+       }
+
+       spi_message_add_tail(&t, &m);
+
+       ret = spi_sync(spi, &m);
+       if (ret)
+               dev_err(&spi->dev, "spi transfer failed: ret = %d\n", ret);
+       return ret;
+}
+
+static u8 mcp251x_read_reg(struct spi_device *spi, uint8_t reg)
+{
+       struct mcp251x_priv *priv = spi_get_drvdata(spi);
+       u8 val = 0;
+
+       priv->spi_tx_buf[0] = INSTRUCTION_READ;
+       priv->spi_tx_buf[1] = reg;
+
+       mcp251x_spi_trans(spi, 3);
+       val = priv->spi_rx_buf[2];
+
+       return val;
+}
+
+static void mcp251x_read_2regs(struct spi_device *spi, uint8_t reg,
+               uint8_t *v1, uint8_t *v2)
+{
+       struct mcp251x_priv *priv = spi_get_drvdata(spi);
+
+       priv->spi_tx_buf[0] = INSTRUCTION_READ;
+       priv->spi_tx_buf[1] = reg;
+
+       mcp251x_spi_trans(spi, 4);
+
+       *v1 = priv->spi_rx_buf[2];
+       *v2 = priv->spi_rx_buf[3];
+}
+
+static void mcp251x_write_reg(struct spi_device *spi, u8 reg, uint8_t val)
+{
+       struct mcp251x_priv *priv = spi_get_drvdata(spi);
+
+       priv->spi_tx_buf[0] = INSTRUCTION_WRITE;
+       priv->spi_tx_buf[1] = reg;
+       priv->spi_tx_buf[2] = val;
+
+       mcp251x_spi_trans(spi, 3);
+}
+
+static void mcp251x_write_bits(struct spi_device *spi, u8 reg,
+                              u8 mask, uint8_t val)
+{
+       struct mcp251x_priv *priv = spi_get_drvdata(spi);
+
+       priv->spi_tx_buf[0] = INSTRUCTION_BIT_MODIFY;
+       priv->spi_tx_buf[1] = reg;
+       priv->spi_tx_buf[2] = mask;
+       priv->spi_tx_buf[3] = val;
+
+       mcp251x_spi_trans(spi, 4);
+}
+
+static void mcp251x_hw_tx_frame(struct spi_device *spi, u8 *buf,
+                               int len, int tx_buf_idx)
+{
+       struct mcp251x_priv *priv = spi_get_drvdata(spi);
+
+       if (mcp251x_is_2510(spi)) {
+               int i;
+
+               for (i = 1; i < TXBDAT_OFF + len; i++)
+                       mcp251x_write_reg(spi, TXBCTRL(tx_buf_idx) + i,
+                                         buf[i]);
+       } else {
+               memcpy(priv->spi_tx_buf, buf, TXBDAT_OFF + len);
+               mcp251x_spi_trans(spi, TXBDAT_OFF + len);
+       }
+}
+
+static void mcp251x_hw_tx(struct spi_device *spi, struct can_frame *frame,
+                         int tx_buf_idx)
+{
+       struct mcp251x_priv *priv = spi_get_drvdata(spi);
+       u32 sid, eid, exide, rtr;
+       u8 buf[SPI_TRANSFER_BUF_LEN];
+
+       exide = (frame->can_id & CAN_EFF_FLAG) ? 1 : 0; /* Extended ID Enable */
+       if (exide)
+               sid = (frame->can_id & CAN_EFF_MASK) >> 18;
+       else
+               sid = frame->can_id & CAN_SFF_MASK; /* Standard ID */
+       eid = frame->can_id & CAN_EFF_MASK; /* Extended ID */
+       rtr = (frame->can_id & CAN_RTR_FLAG) ? 1 : 0; /* Remote transmission */
+
+       buf[TXBCTRL_OFF] = INSTRUCTION_LOAD_TXB(tx_buf_idx);
+       buf[TXBSIDH_OFF] = sid >> SIDH_SHIFT;
+       buf[TXBSIDL_OFF] = ((sid & SIDL_SID_MASK) << SIDL_SID_SHIFT) |
+               (exide << SIDL_EXIDE_SHIFT) |
+               ((eid >> SIDL_EID_SHIFT) & SIDL_EID_MASK);
+       buf[TXBEID8_OFF] = GET_BYTE(eid, 1);
+       buf[TXBEID0_OFF] = GET_BYTE(eid, 0);
+       buf[TXBDLC_OFF] = (rtr << DLC_RTR_SHIFT) | frame->can_dlc;
+       memcpy(buf + TXBDAT_OFF, frame->data, frame->can_dlc);
+       mcp251x_hw_tx_frame(spi, buf, frame->can_dlc, tx_buf_idx);
+
+       /* use INSTRUCTION_RTS, to avoid "repeated frame problem" */
+       priv->spi_tx_buf[0] = INSTRUCTION_RTS(1 << tx_buf_idx);
+       mcp251x_spi_trans(priv->spi, 1);
+}
+
+static void mcp251x_hw_rx_frame(struct spi_device *spi, u8 *buf,
+                               int buf_idx)
+{
+       struct mcp251x_priv *priv = spi_get_drvdata(spi);
+
+       if (mcp251x_is_2510(spi)) {
+               int i, len;
+
+               for (i = 1; i < RXBDAT_OFF; i++)
+                       buf[i] = mcp251x_read_reg(spi, RXBCTRL(buf_idx) + i);
+
+               len = get_can_dlc(buf[RXBDLC_OFF] & RXBDLC_LEN_MASK);
+               for (; i < (RXBDAT_OFF + len); i++)
+                       buf[i] = mcp251x_read_reg(spi, RXBCTRL(buf_idx) + i);
+       } else {
+               priv->spi_tx_buf[RXBCTRL_OFF] = INSTRUCTION_READ_RXB(buf_idx);
+               mcp251x_spi_trans(spi, SPI_TRANSFER_BUF_LEN);
+               memcpy(buf, priv->spi_rx_buf, SPI_TRANSFER_BUF_LEN);
+       }
+}
+
+static void mcp251x_hw_rx(struct spi_device *spi, int buf_idx)
+{
+       struct mcp251x_priv *priv = spi_get_drvdata(spi);
+       struct sk_buff *skb;
+       struct can_frame *frame;
+       u8 buf[SPI_TRANSFER_BUF_LEN];
+
+       skb = alloc_can_skb(priv->net, &frame);
+       if (!skb) {
+               dev_err(&spi->dev, "cannot allocate RX skb\n");
+               priv->net->stats.rx_dropped++;
+               return;
+       }
+
+       mcp251x_hw_rx_frame(spi, buf, buf_idx);
+       if (buf[RXBSIDL_OFF] & RXBSIDL_IDE) {
+               /* Extended ID format */
+               frame->can_id = CAN_EFF_FLAG;
+               frame->can_id |=
+                       /* Extended ID part */
+                       SET_BYTE(buf[RXBSIDL_OFF] & RXBSIDL_EID, 2) |
+                       SET_BYTE(buf[RXBEID8_OFF], 1) |
+                       SET_BYTE(buf[RXBEID0_OFF], 0) |
+                       /* Standard ID part */
+                       (((buf[RXBSIDH_OFF] << RXBSIDH_SHIFT) |
+                         (buf[RXBSIDL_OFF] >> RXBSIDL_SHIFT)) << 18);
+               /* Remote transmission request */
+               if (buf[RXBDLC_OFF] & RXBDLC_RTR)
+                       frame->can_id |= CAN_RTR_FLAG;
+       } else {
+               /* Standard ID format */
+               frame->can_id =
+                       (buf[RXBSIDH_OFF] << RXBSIDH_SHIFT) |
+                       (buf[RXBSIDL_OFF] >> RXBSIDL_SHIFT);
+               if (buf[RXBSIDL_OFF] & RXBSIDL_SRR)
+                       frame->can_id |= CAN_RTR_FLAG;
+       }
+       /* Data length */
+       frame->can_dlc = get_can_dlc(buf[RXBDLC_OFF] & RXBDLC_LEN_MASK);
+       memcpy(frame->data, buf + RXBDAT_OFF, frame->can_dlc);
+
+       priv->net->stats.rx_packets++;
+       priv->net->stats.rx_bytes += frame->can_dlc;
+
+       can_led_event(priv->net, CAN_LED_EVENT_RX);
+
+       netif_rx_ni(skb);
+}
+
+static void mcp251x_hw_sleep(struct spi_device *spi)
+{
+       mcp251x_write_reg(spi, CANCTRL, CANCTRL_REQOP_SLEEP);
+}
+
+static netdev_tx_t mcp251x_hard_start_xmit(struct sk_buff *skb,
+                                          struct net_device *net)
+{
+       struct mcp251x_priv *priv = netdev_priv(net);
+       struct spi_device *spi = priv->spi;
+
+       if (priv->tx_skb || priv->tx_len) {
+               dev_warn(&spi->dev, "hard_xmit called while tx busy\n");
+               return NETDEV_TX_BUSY;
+       }
+
+       if (can_dropped_invalid_skb(net, skb))
+               return NETDEV_TX_OK;
+
+       netif_stop_queue(net);
+       priv->tx_skb = skb;
+       queue_work(priv->wq, &priv->tx_work);
+
+       return NETDEV_TX_OK;
+}
+
+static int mcp251x_do_set_mode(struct net_device *net, enum can_mode mode)
+{
+       struct mcp251x_priv *priv = netdev_priv(net);
+
+       switch (mode) {
+       case CAN_MODE_START:
+               mcp251x_clean(net);
+               /* We have to delay work since SPI I/O may sleep */
+               priv->can.state = CAN_STATE_ERROR_ACTIVE;
+               priv->restart_tx = 1;
+               if (priv->can.restart_ms == 0)
+                       priv->after_suspend = AFTER_SUSPEND_RESTART;
+               queue_work(priv->wq, &priv->restart_work);
+               break;
+       default:
+               return -EOPNOTSUPP;
+       }
+
+       return 0;
+}
+
+static int mcp251x_set_normal_mode(struct spi_device *spi)
+{
+       struct mcp251x_priv *priv = spi_get_drvdata(spi);
+       unsigned long timeout;
+
+       /* Enable interrupts */
+       mcp251x_write_reg(spi, CANINTE,
+                         CANINTE_ERRIE | CANINTE_TX2IE | CANINTE_TX1IE |
+                         CANINTE_TX0IE | CANINTE_RX1IE | CANINTE_RX0IE);
+
+       if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK) {
+               /* Put device into loopback mode */
+               mcp251x_write_reg(spi, CANCTRL, CANCTRL_REQOP_LOOPBACK);
+       } else if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY) {
+               /* Put device into listen-only mode */
+               mcp251x_write_reg(spi, CANCTRL, CANCTRL_REQOP_LISTEN_ONLY);
+       } else {
+               /* Put device into normal mode */
+               mcp251x_write_reg(spi, CANCTRL, CANCTRL_REQOP_NORMAL);
+
+               /* Wait for the device to enter normal mode */
+               timeout = jiffies + HZ;
+               while (mcp251x_read_reg(spi, CANSTAT) & CANCTRL_REQOP_MASK) {
+                       schedule();
+                       if (time_after(jiffies, timeout)) {
+                               dev_err(&spi->dev, "MCP251x didn't"
+                                       " enter in normal mode\n");
+                               return -EBUSY;
+                       }
+               }
+       }
+       priv->can.state = CAN_STATE_ERROR_ACTIVE;
+       return 0;
+}
+
+static int mcp251x_do_set_bittiming(struct net_device *net)
+{
+       struct mcp251x_priv *priv = netdev_priv(net);
+       struct can_bittiming *bt = &priv->can.bittiming;
+       struct spi_device *spi = priv->spi;
+
+       mcp251x_write_reg(spi, CNF1, ((bt->sjw - 1) << CNF1_SJW_SHIFT) |
+                         (bt->brp - 1));
+       mcp251x_write_reg(spi, CNF2, CNF2_BTLMODE |
+                         (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES ?
+                          CNF2_SAM : 0) |
+                         ((bt->phase_seg1 - 1) << CNF2_PS1_SHIFT) |
+                         (bt->prop_seg - 1));
+       mcp251x_write_bits(spi, CNF3, CNF3_PHSEG2_MASK,
+                          (bt->phase_seg2 - 1));
+       dev_dbg(&spi->dev, "CNF: 0x%02x 0x%02x 0x%02x\n",
+               mcp251x_read_reg(spi, CNF1),
+               mcp251x_read_reg(spi, CNF2),
+               mcp251x_read_reg(spi, CNF3));
+
+       return 0;
+}
+
+static int mcp251x_setup(struct net_device *net, struct mcp251x_priv *priv,
+                        struct spi_device *spi)
+{
+       mcp251x_do_set_bittiming(net);
+
+       mcp251x_write_reg(spi, RXBCTRL(0),
+                         RXBCTRL_BUKT | RXBCTRL_RXM0 | RXBCTRL_RXM1);
+       mcp251x_write_reg(spi, RXBCTRL(1),
+                         RXBCTRL_RXM0 | RXBCTRL_RXM1);
+       return 0;
+}
+
+static int mcp251x_hw_reset(struct spi_device *spi)
+{
+       struct mcp251x_priv *priv = spi_get_drvdata(spi);
+       u8 reg;
+       int ret;
+
+       /* Wait for oscillator startup timer after power up */
+       mdelay(MCP251X_OST_DELAY_MS);
+
+       priv->spi_tx_buf[0] = INSTRUCTION_RESET;
+       ret = mcp251x_spi_trans(spi, 1);
+       if (ret)
+               return ret;
+
+       /* Wait for oscillator startup timer after reset */
+       mdelay(MCP251X_OST_DELAY_MS);
+       
+       reg = mcp251x_read_reg(spi, CANSTAT);
+       if ((reg & CANCTRL_REQOP_MASK) != CANCTRL_REQOP_CONF)
+               return -ENODEV;
+
+       return 0;
+}
+
+static int mcp251x_hw_probe(struct spi_device *spi)
+{
+       u8 ctrl;
+       int ret;
+
+       ret = mcp251x_hw_reset(spi);
+       if (ret)
+               return ret;
+
+       ctrl = mcp251x_read_reg(spi, CANCTRL);
+
+       dev_dbg(&spi->dev, "CANCTRL 0x%02x\n", ctrl);
+
+       /* Check for power up default value */
+       if ((ctrl & 0x17) != 0x07)
+               return -ENODEV;
+
+       return 0;
+}
+
+static int mcp251x_power_enable(struct regulator *reg, int enable)
+{
+       if (IS_ERR_OR_NULL(reg))
+               return 0;
+
+       if (enable)
+               return regulator_enable(reg);
+       else
+               return regulator_disable(reg);
+}
+
+static void mcp251x_open_clean(struct net_device *net)
+{
+       struct mcp251x_priv *priv = netdev_priv(net);
+       struct spi_device *spi = priv->spi;
+
+       free_irq(spi->irq, priv);
+       mcp251x_hw_sleep(spi);
+       mcp251x_power_enable(priv->transceiver, 0);
+       close_candev(net);
+}
+
+static int mcp251x_stop(struct net_device *net)
+{
+       struct mcp251x_priv *priv = netdev_priv(net);
+       struct spi_device *spi = priv->spi;
+
+       close_candev(net);
+
+       priv->force_quit = 1;
+       free_irq(spi->irq, priv);
+       destroy_workqueue(priv->wq);
+       priv->wq = NULL;
+
+       mutex_lock(&priv->mcp_lock);
+
+       /* Disable and clear pending interrupts */
+       mcp251x_write_reg(spi, CANINTE, 0x00);
+       mcp251x_write_reg(spi, CANINTF, 0x00);
+
+       mcp251x_write_reg(spi, TXBCTRL(0), 0);
+       mcp251x_clean(net);
+
+       mcp251x_hw_sleep(spi);
+
+       mcp251x_power_enable(priv->transceiver, 0);
+
+       priv->can.state = CAN_STATE_STOPPED;
+
+       mutex_unlock(&priv->mcp_lock);
+
+       can_led_event(net, CAN_LED_EVENT_STOP);
+
+       return 0;
+}
+
+static void mcp251x_error_skb(struct net_device *net, int can_id, int data1)
+{
+       struct sk_buff *skb;
+       struct can_frame *frame;
+
+       skb = alloc_can_err_skb(net, &frame);
+       if (skb) {
+               frame->can_id |= can_id;
+               frame->data[1] = data1;
+               netif_rx_ni(skb);
+       } else {
+               netdev_err(net, "cannot allocate error skb\n");
+       }
+}
+
+static void mcp251x_tx_work_handler(struct work_struct *ws)
+{
+       struct mcp251x_priv *priv = container_of(ws, struct mcp251x_priv,
+                                                tx_work);
+       struct spi_device *spi = priv->spi;
+       struct net_device *net = priv->net;
+       struct can_frame *frame;
+
+       mutex_lock(&priv->mcp_lock);
+       if (priv->tx_skb) {
+               if (priv->can.state == CAN_STATE_BUS_OFF) {
+                       mcp251x_clean(net);
+               } else {
+                       frame = (struct can_frame *)priv->tx_skb->data;
+
+                       if (frame->can_dlc > CAN_FRAME_MAX_DATA_LEN)
+                               frame->can_dlc = CAN_FRAME_MAX_DATA_LEN;
+                       mcp251x_hw_tx(spi, frame, 0);
+                       priv->tx_len = 1 + frame->can_dlc;
+                       can_put_echo_skb(priv->tx_skb, net, 0);
+                       priv->tx_skb = NULL;
+               }
+       }
+       mutex_unlock(&priv->mcp_lock);
+}
+
+static void mcp251x_restart_work_handler(struct work_struct *ws)
+{
+       struct mcp251x_priv *priv = container_of(ws, struct mcp251x_priv,
+                                                restart_work);
+       struct spi_device *spi = priv->spi;
+       struct net_device *net = priv->net;
+
+       mutex_lock(&priv->mcp_lock);
+       if (priv->after_suspend) {
+               mcp251x_hw_reset(spi);
+               mcp251x_setup(net, priv, spi);
+               if (priv->after_suspend & AFTER_SUSPEND_RESTART) {
+                       mcp251x_set_normal_mode(spi);
+               } else if (priv->after_suspend & AFTER_SUSPEND_UP) {
+                       netif_device_attach(net);
+                       mcp251x_clean(net);
+                       mcp251x_set_normal_mode(spi);
+                       netif_wake_queue(net);
+               } else {
+                       mcp251x_hw_sleep(spi);
+               }
+               priv->after_suspend = 0;
+               priv->force_quit = 0;
+       }
+
+       if (priv->restart_tx) {
+               priv->restart_tx = 0;
+               mcp251x_write_reg(spi, TXBCTRL(0), 0);
+               mcp251x_clean(net);
+               netif_wake_queue(net);
+               mcp251x_error_skb(net, CAN_ERR_RESTARTED, 0);
+       }
+       mutex_unlock(&priv->mcp_lock);
+}
+
+static irqreturn_t mcp251x_can_ist(int irq, void *dev_id)
+{
+       struct mcp251x_priv *priv = dev_id;
+       struct spi_device *spi = priv->spi;
+       struct net_device *net = priv->net;
+
+       mutex_lock(&priv->mcp_lock);
+       while (!priv->force_quit) {
+               enum can_state new_state;
+               u8 intf, eflag;
+               u8 clear_intf = 0;
+               int can_id = 0, data1 = 0;
+
+               mcp251x_read_2regs(spi, CANINTF, &intf, &eflag);
+
+               /* mask out flags we don't care about */
+               intf &= CANINTF_RX | CANINTF_TX | CANINTF_ERR;
+
+               /* receive buffer 0 */
+               if (intf & CANINTF_RX0IF) {
+                       mcp251x_hw_rx(spi, 0);
+                       /*
+                        * Free one buffer ASAP
+                        * (The MCP2515 does this automatically.)
+                        */
+                       if (mcp251x_is_2510(spi))
+                               mcp251x_write_bits(spi, CANINTF, CANINTF_RX0IF, 0x00);
+               }
+
+               /* receive buffer 1 */
+               if (intf & CANINTF_RX1IF) {
+                       mcp251x_hw_rx(spi, 1);
+                       /* the MCP2515 does this automatically */
+                       if (mcp251x_is_2510(spi))
+                               clear_intf |= CANINTF_RX1IF;
+               }
+
+               /* any error or tx interrupt we need to clear? */
+               if (intf & (CANINTF_ERR | CANINTF_TX))
+                       clear_intf |= intf & (CANINTF_ERR | CANINTF_TX);
+               if (clear_intf)
+                       mcp251x_write_bits(spi, CANINTF, clear_intf, 0x00);
+
+               if (eflag)
+                       mcp251x_write_bits(spi, EFLG, eflag, 0x00);
+
+               /* Update can state */
+               if (eflag & EFLG_TXBO) {
+                       new_state = CAN_STATE_BUS_OFF;
+                       can_id |= CAN_ERR_BUSOFF;
+               } else if (eflag & EFLG_TXEP) {
+                       new_state = CAN_STATE_ERROR_PASSIVE;
+                       can_id |= CAN_ERR_CRTL;
+                       data1 |= CAN_ERR_CRTL_TX_PASSIVE;
+               } else if (eflag & EFLG_RXEP) {
+                       new_state = CAN_STATE_ERROR_PASSIVE;
+                       can_id |= CAN_ERR_CRTL;
+                       data1 |= CAN_ERR_CRTL_RX_PASSIVE;
+               } else if (eflag & EFLG_TXWAR) {
+                       new_state = CAN_STATE_ERROR_WARNING;
+                       can_id |= CAN_ERR_CRTL;
+                       data1 |= CAN_ERR_CRTL_TX_WARNING;
+               } else if (eflag & EFLG_RXWAR) {
+                       new_state = CAN_STATE_ERROR_WARNING;
+                       can_id |= CAN_ERR_CRTL;
+                       data1 |= CAN_ERR_CRTL_RX_WARNING;
+               } else {
+                       new_state = CAN_STATE_ERROR_ACTIVE;
+               }
+
+               /* Update can state statistics */
+               switch (priv->can.state) {
+               case CAN_STATE_ERROR_ACTIVE:
+                       if (new_state >= CAN_STATE_ERROR_WARNING &&
+                           new_state <= CAN_STATE_BUS_OFF)
+                               priv->can.can_stats.error_warning++;
+               case CAN_STATE_ERROR_WARNING:   /* fallthrough */
+                       if (new_state >= CAN_STATE_ERROR_PASSIVE &&
+                           new_state <= CAN_STATE_BUS_OFF)
+                               priv->can.can_stats.error_passive++;
+                       break;
+               default:
+                       break;
+               }
+               priv->can.state = new_state;
+
+               if (intf & CANINTF_ERRIF) {
+                       /* Handle overflow counters */
+                       if (eflag & (EFLG_RX0OVR | EFLG_RX1OVR)) {
+                               if (eflag & EFLG_RX0OVR) {
+                                       net->stats.rx_over_errors++;
+                                       net->stats.rx_errors++;
+                               }
+                               if (eflag & EFLG_RX1OVR) {
+                                       net->stats.rx_over_errors++;
+                                       net->stats.rx_errors++;
+                               }
+                               can_id |= CAN_ERR_CRTL;
+                               data1 |= CAN_ERR_CRTL_RX_OVERFLOW;
+                       }
+                       mcp251x_error_skb(net, can_id, data1);
+               }
+
+               if (priv->can.state == CAN_STATE_BUS_OFF) {
+                       if (priv->can.restart_ms == 0) {
+                               priv->force_quit = 1;
+                               can_bus_off(net);
+                               mcp251x_hw_sleep(spi);
+                               break;
+                       }
+               }
+
+               if (intf == 0)
+                       break;
+
+               if (intf & CANINTF_TX) {
+                       net->stats.tx_packets++;
+                       net->stats.tx_bytes += priv->tx_len - 1;
+                       can_led_event(net, CAN_LED_EVENT_TX);
+                       if (priv->tx_len) {
+                               can_get_echo_skb(net, 0);
+                               priv->tx_len = 0;
+                       }
+                       netif_wake_queue(net);
+               }
+
+       }
+       mutex_unlock(&priv->mcp_lock);
+       return IRQ_HANDLED;
+}
+
+static int mcp251x_open(struct net_device *net)
+{
+       struct mcp251x_priv *priv = netdev_priv(net);
+       struct spi_device *spi = priv->spi;
+       unsigned long flags = IRQF_ONESHOT | IRQF_TRIGGER_FALLING;
+       int ret;
+
+       ret = open_candev(net);
+       if (ret) {
+               dev_err(&spi->dev, "unable to set initial baudrate!\n");
+               return ret;
+       }
+
+       mutex_lock(&priv->mcp_lock);
+       mcp251x_power_enable(priv->transceiver, 1);
+
+       priv->force_quit = 0;
+       priv->tx_skb = NULL;
+       priv->tx_len = 0;
+
+       ret = request_threaded_irq(spi->irq, NULL, mcp251x_can_ist,
+                                  flags, DEVICE_NAME, priv);
+       if (ret) {
+               dev_err(&spi->dev, "failed to acquire irq %d\n", spi->irq);
+               mcp251x_power_enable(priv->transceiver, 0);
+               close_candev(net);
+               goto open_unlock;
+       }
+
+       priv->wq = create_freezable_workqueue("mcp251x_wq");
+       INIT_WORK(&priv->tx_work, mcp251x_tx_work_handler);
+       INIT_WORK(&priv->restart_work, mcp251x_restart_work_handler);
+
+       ret = mcp251x_hw_reset(spi);
+       if (ret) {
+               mcp251x_open_clean(net);
+               goto open_unlock;
+       }
+       ret = mcp251x_setup(net, priv, spi);
+       if (ret) {
+               mcp251x_open_clean(net);
+               goto open_unlock;
+       }
+       ret = mcp251x_set_normal_mode(spi);
+       if (ret) {
+               mcp251x_open_clean(net);
+               goto open_unlock;
+       }
+
+       can_led_event(net, CAN_LED_EVENT_OPEN);
+
+       netif_wake_queue(net);
+
+open_unlock:
+       mutex_unlock(&priv->mcp_lock);
+       return ret;
+}
+
+static const struct net_device_ops mcp251x_netdev_ops = {
+       .ndo_open = mcp251x_open,
+       .ndo_stop = mcp251x_stop,
+       .ndo_start_xmit = mcp251x_hard_start_xmit,
+       .ndo_change_mtu = can_change_mtu,
+};
+
+static const struct of_device_id mcp251x_of_match[] = {
+       {
+               .compatible     = "microchip,mcp2510",
+               .data           = (void *)CAN_MCP251X_MCP2510,
+       },
+       {
+               .compatible     = "microchip,mcp2515",
+               .data           = (void *)CAN_MCP251X_MCP2515,
+       },
+       { }
+};
+MODULE_DEVICE_TABLE(of, mcp251x_of_match);
+
+static const struct spi_device_id mcp251x_id_table[] = {
+       {
+               .name           = "mcp2510",
+               .driver_data    = (kernel_ulong_t)CAN_MCP251X_MCP2510,
+       },
+       {
+               .name           = "mcp2515",
+               .driver_data    = (kernel_ulong_t)CAN_MCP251X_MCP2515,
+       },
+       { }
+};
+MODULE_DEVICE_TABLE(spi, mcp251x_id_table);
+
+static int mcp251x_can_probe(struct spi_device *spi)
+{
+       const struct of_device_id *of_id = of_match_device(mcp251x_of_match,
+                                                          &spi->dev);
+       struct mcp251x_platform_data *pdata = dev_get_platdata(&spi->dev);
+       struct net_device *net;
+       struct mcp251x_priv *priv;
+       struct clk *clk;
+       int freq, ret;
+
+       clk = devm_clk_get(&spi->dev, NULL);
+       if (IS_ERR(clk)) {
+               if (pdata)
+                       freq = pdata->oscillator_frequency;
+               else
+                       return PTR_ERR(clk);
+       } else {
+               freq = clk_get_rate(clk);
+       }
+
+       /* Sanity check */
+       if (freq < 1000000 || freq > 25000000)
+               return -ERANGE;
+
+       /* Allocate can/net device */
+       net = alloc_candev(sizeof(struct mcp251x_priv), TX_ECHO_SKB_MAX);
+       if (!net)
+               return -ENOMEM;
+
+       if (!IS_ERR(clk)) {
+               ret = clk_prepare_enable(clk);
+               if (ret)
+                       goto out_free;
+       }
+
+       net->netdev_ops = &mcp251x_netdev_ops;
+       net->flags |= IFF_ECHO;
+
+       priv = netdev_priv(net);
+       priv->can.bittiming_const = &mcp251x_bittiming_const;
+       priv->can.do_set_mode = mcp251x_do_set_mode;
+       priv->can.clock.freq = freq / 2;
+       priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES |
+               CAN_CTRLMODE_LOOPBACK | CAN_CTRLMODE_LISTENONLY;
+       if (of_id)
+               priv->model = (enum mcp251x_model)of_id->data;
+       else
+               priv->model = spi_get_device_id(spi)->driver_data;
+       priv->net = net;
+       priv->clk = clk;
+
+       spi_set_drvdata(spi, priv);
+
+       /* Configure the SPI bus */
+       spi->bits_per_word = 8;
+       if (mcp251x_is_2510(spi))
+               spi->max_speed_hz = spi->max_speed_hz ? : 5 * 1000 * 1000;
+       else
+               spi->max_speed_hz = spi->max_speed_hz ? : 10 * 1000 * 1000;
+       ret = spi_setup(spi);
+       if (ret)
+               goto out_clk;
+
+       priv->power = devm_regulator_get(&spi->dev, "vdd");
+       priv->transceiver = devm_regulator_get(&spi->dev, "xceiver");
+       if ((PTR_ERR(priv->power) == -EPROBE_DEFER) ||
+           (PTR_ERR(priv->transceiver) == -EPROBE_DEFER)) {
+               ret = -EPROBE_DEFER;
+               goto out_clk;
+       }
+
+       ret = mcp251x_power_enable(priv->power, 1);
+       if (ret)
+               goto out_clk;
+
+       priv->spi = spi;
+       mutex_init(&priv->mcp_lock);
+
+       /* If requested, allocate DMA buffers */
+       if (mcp251x_enable_dma) {
+               spi->dev.coherent_dma_mask = ~0;
+
+               /*
+                * Minimum coherent DMA allocation is PAGE_SIZE, so allocate
+                * that much and share it between Tx and Rx DMA buffers.
+                */
+               priv->spi_tx_buf = dma_alloc_coherent(&spi->dev,
+                                                     PAGE_SIZE,
+                                                     &priv->spi_tx_dma,
+                                                     GFP_DMA);
+
+               if (priv->spi_tx_buf) {
+                       priv->spi_rx_buf = (priv->spi_tx_buf + (PAGE_SIZE / 2));
+                       priv->spi_rx_dma = (dma_addr_t)(priv->spi_tx_dma +
+                                                       (PAGE_SIZE / 2));
+               } else {
+                       /* Fall back to non-DMA */
+                       mcp251x_enable_dma = 0;
+               }
+       }
+
+       /* Allocate non-DMA buffers */
+       if (!mcp251x_enable_dma) {
+               priv->spi_tx_buf = devm_kzalloc(&spi->dev, SPI_TRANSFER_BUF_LEN,
+                                               GFP_KERNEL);
+               if (!priv->spi_tx_buf) {
+                       ret = -ENOMEM;
+                       goto error_probe;
+               }
+               priv->spi_rx_buf = devm_kzalloc(&spi->dev, SPI_TRANSFER_BUF_LEN,
+                                               GFP_KERNEL);
+               if (!priv->spi_rx_buf) {
+                       ret = -ENOMEM;
+                       goto error_probe;
+               }
+       }
+
+       SET_NETDEV_DEV(net, &spi->dev);
+
+       /* Here is OK to not lock the MCP, no one knows about it yet */
+       ret = mcp251x_hw_probe(spi);
+       if (ret)
+               goto error_probe;
+
+       mcp251x_hw_sleep(spi);
+
+       ret = register_candev(net);
+       if (ret)
+               goto error_probe;
+
+       devm_can_led_init(net);
+
+       return 0;
+
+error_probe:
+       if (mcp251x_enable_dma)
+               dma_free_coherent(&spi->dev, PAGE_SIZE,
+                                 priv->spi_tx_buf, priv->spi_tx_dma);
+       mcp251x_power_enable(priv->power, 0);
+
+out_clk:
+       if (!IS_ERR(clk))
+               clk_disable_unprepare(clk);
+
+out_free:
+       free_candev(net);
+
+       return ret;
+}
+
+static int mcp251x_can_remove(struct spi_device *spi)
+{
+       struct mcp251x_priv *priv = spi_get_drvdata(spi);
+       struct net_device *net = priv->net;
+
+       unregister_candev(net);
+
+       if (mcp251x_enable_dma) {
+               dma_free_coherent(&spi->dev, PAGE_SIZE,
+                                 priv->spi_tx_buf, priv->spi_tx_dma);
+       }
+
+       mcp251x_power_enable(priv->power, 0);
+
+       if (!IS_ERR(priv->clk))
+               clk_disable_unprepare(priv->clk);
+
+       free_candev(net);
+
+       return 0;
+}
+
+static int __maybe_unused mcp251x_can_suspend(struct device *dev)
+{
+       struct spi_device *spi = to_spi_device(dev);
+       struct mcp251x_priv *priv = spi_get_drvdata(spi);
+       struct net_device *net = priv->net;
+
+       priv->force_quit = 1;
+       disable_irq(spi->irq);
+       /*
+        * Note: at this point neither IST nor workqueues are running.
+        * open/stop cannot be called anyway so locking is not needed
+        */
+       if (netif_running(net)) {
+               netif_device_detach(net);
+
+               mcp251x_hw_sleep(spi);
+               mcp251x_power_enable(priv->transceiver, 0);
+               priv->after_suspend = AFTER_SUSPEND_UP;
+       } else {
+               priv->after_suspend = AFTER_SUSPEND_DOWN;
+       }
+
+       if (!IS_ERR_OR_NULL(priv->power)) {
+               regulator_disable(priv->power);
+               priv->after_suspend |= AFTER_SUSPEND_POWER;
+       }
+
+       return 0;
+}
+
+static int __maybe_unused mcp251x_can_resume(struct device *dev)
+{
+       struct spi_device *spi = to_spi_device(dev);
+       struct mcp251x_priv *priv = spi_get_drvdata(spi);
+
+       if (priv->after_suspend & AFTER_SUSPEND_POWER) {
+               mcp251x_power_enable(priv->power, 1);
+               queue_work(priv->wq, &priv->restart_work);
+       } else {
+               if (priv->after_suspend & AFTER_SUSPEND_UP) {
+                       mcp251x_power_enable(priv->transceiver, 1);
+                       queue_work(priv->wq, &priv->restart_work);
+               } else {
+                       priv->after_suspend = 0;
+               }
+       }
+       priv->force_quit = 0;
+       enable_irq(spi->irq);
+       return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(mcp251x_can_pm_ops, mcp251x_can_suspend,
+       mcp251x_can_resume);
+
+static struct spi_driver mcp251x_can_driver = {
+       .driver = {
+               .name = DEVICE_NAME,
+               .owner = THIS_MODULE,
+               .of_match_table = mcp251x_of_match,
+               .pm = &mcp251x_can_pm_ops,
+       },
+       .id_table = mcp251x_id_table,
+       .probe = mcp251x_can_probe,
+       .remove = mcp251x_can_remove,
+};
+module_spi_driver(mcp251x_can_driver);
+
+MODULE_AUTHOR("Chris Elston <celston@katalix.com>, "
+             "Christian Pellegrin <chripell@evolware.org>");
+MODULE_DESCRIPTION("Microchip 251x CAN driver");
+MODULE_LICENSE("GPL v2");