net: broadcom: bcm4908enet: add BCM4908 controller driver
authorRafał Miłecki <rafal@milecki.pl>
Sun, 7 Feb 2021 22:26:32 +0000 (23:26 +0100)
committerDavid S. Miller <davem@davemloft.net>
Tue, 9 Feb 2021 19:34:53 +0000 (11:34 -0800)
BCM4908 SoCs family uses Ethernel controller that includes UniMAC but
uses different DMA engine (than other controllers) and requires
different programming.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>
MAINTAINERS
drivers/net/ethernet/broadcom/Kconfig
drivers/net/ethernet/broadcom/Makefile
drivers/net/ethernet/broadcom/bcm4908enet.c [new file with mode: 0644]
drivers/net/ethernet/broadcom/bcm4908enet.h [new file with mode: 0644]

index d1b0057..cbf4b94 100644 (file)
@@ -3445,6 +3445,15 @@ F:       Documentation/devicetree/bindings/mips/brcm/
 F:     arch/mips/bcm47xx/*
 F:     arch/mips/include/asm/mach-bcm47xx/*
 
+BROADCOM BCM4908 ETHERNET DRIVER
+M:     Rafał Miłecki <rafal@milecki.pl>
+M:     bcm-kernel-feedback-list@broadcom.com
+L:     netdev@vger.kernel.org
+S:     Maintained
+F:     Documentation/devicetree/bindings/net/brcm,bcm4908enet.yaml
+F:     drivers/net/ethernet/broadcom/bcm4908enet.*
+F:     drivers/net/ethernet/broadcom/unimac.h
+
 BROADCOM BCM5301X ARM ARCHITECTURE
 M:     Hauke Mehrtens <hauke@hauke-m.de>
 M:     Rafał Miłecki <zajec5@gmail.com>
index 4bdf8fb..bcf9e0a 100644 (file)
@@ -51,6 +51,14 @@ config B44_PCI
        depends on B44_PCI_AUTOSELECT && B44_PCICORE_AUTOSELECT
        default y
 
+config BCM4908ENET
+       tristate "Broadcom BCM4908 internal mac support"
+       depends on ARCH_BCM4908 || COMPILE_TEST
+       default y
+       help
+         This driver supports Ethernet controller integrated into Broadcom
+         BCM4908 family SoCs.
+
 config BCM63XX_ENET
        tristate "Broadcom 63xx internal mac support"
        depends on BCM63XX
index 7046ad6..379012d 100644 (file)
@@ -4,6 +4,7 @@
 #
 
 obj-$(CONFIG_B44) += b44.o
+obj-$(CONFIG_BCM4908ENET) += bcm4908enet.o
 obj-$(CONFIG_BCM63XX_ENET) += bcm63xx_enet.o
 obj-$(CONFIG_BCMGENET) += genet/
 obj-$(CONFIG_BNX2) += bnx2.o
diff --git a/drivers/net/ethernet/broadcom/bcm4908enet.c b/drivers/net/ethernet/broadcom/bcm4908enet.c
new file mode 100644 (file)
index 0000000..d68b328
--- /dev/null
@@ -0,0 +1,676 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2021 Rafał Miłecki <rafal@milecki.pl>
+ */
+
+#include <linux/delay.h>
+#include <linux/etherdevice.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+
+#include "bcm4908enet.h"
+#include "unimac.h"
+
+#define ENET_DMA_CH_RX_CFG                     ENET_DMA_CH0_CFG
+#define ENET_DMA_CH_TX_CFG                     ENET_DMA_CH1_CFG
+#define ENET_DMA_CH_RX_STATE_RAM               ENET_DMA_CH0_STATE_RAM
+#define ENET_DMA_CH_TX_STATE_RAM               ENET_DMA_CH1_STATE_RAM
+
+#define ENET_TX_BDS_NUM                                200
+#define ENET_RX_BDS_NUM                                200
+#define ENET_RX_BDS_NUM_MAX                    8192
+
+#define ENET_DMA_INT_DEFAULTS                  (ENET_DMA_CH_CFG_INT_DONE | \
+                                                ENET_DMA_CH_CFG_INT_NO_DESC | \
+                                                ENET_DMA_CH_CFG_INT_BUFF_DONE)
+#define ENET_DMA_MAX_BURST_LEN                 8 /* in 64 bit words */
+
+#define ENET_MTU_MIN                           60
+#define ENET_MTU_MAX                           1500 /* Is it possible to support 2044? */
+#define ENET_MTU_MAX_EXTRA_SIZE                        32 /* L2 */
+
+struct bcm4908enet_dma_ring_bd {
+       __le32 ctl;
+       __le32 addr;
+} __packed;
+
+struct bcm4908enet_dma_ring_slot {
+       struct sk_buff *skb;
+       unsigned int len;
+       dma_addr_t dma_addr;
+};
+
+struct bcm4908enet_dma_ring {
+       int is_tx;
+       int read_idx;
+       int write_idx;
+       int length;
+       u16 cfg_block;
+       u16 st_ram_block;
+
+       union {
+               void *cpu_addr;
+               struct bcm4908enet_dma_ring_bd *buf_desc;
+       };
+       dma_addr_t dma_addr;
+
+       struct bcm4908enet_dma_ring_slot *slots;
+};
+
+struct bcm4908enet {
+       struct device *dev;
+       struct net_device *netdev;
+       struct napi_struct napi;
+       void __iomem *base;
+
+       struct bcm4908enet_dma_ring tx_ring;
+       struct bcm4908enet_dma_ring rx_ring;
+};
+
+/***
+ * R/W ops
+ */
+
+static inline u32 enet_read(struct bcm4908enet *enet, u16 offset)
+{
+       return readl(enet->base + offset);
+}
+
+static inline void enet_write(struct bcm4908enet *enet, u16 offset, u32 value)
+{
+       writel(value, enet->base + offset);
+}
+
+static inline void enet_maskset(struct bcm4908enet *enet, u16 offset, u32 mask, u32 set)
+{
+       u32 val;
+
+       WARN_ON(set & ~mask);
+
+       val = enet_read(enet, offset);
+       val = (val & ~mask) | (set & mask);
+       enet_write(enet, offset, val);
+}
+
+static inline void enet_set(struct bcm4908enet *enet, u16 offset, u32 set)
+{
+       enet_maskset(enet, offset, set, set);
+}
+
+static inline u32 enet_umac_read(struct bcm4908enet *enet, u16 offset)
+{
+       return enet_read(enet, ENET_UNIMAC + offset);
+}
+
+static inline void enet_umac_write(struct bcm4908enet *enet, u16 offset, u32 value)
+{
+       enet_write(enet, ENET_UNIMAC + offset, value);
+}
+
+static inline void enet_umac_maskset(struct bcm4908enet *enet, u16 offset, u32 mask, u32 set)
+{
+       enet_maskset(enet, ENET_UNIMAC + offset, mask, set);
+}
+
+static inline void enet_umac_set(struct bcm4908enet *enet, u16 offset, u32 set)
+{
+       enet_set(enet, ENET_UNIMAC + offset, set);
+}
+
+/***
+ * Helpers
+ */
+
+static void bcm4908enet_intrs_on(struct bcm4908enet *enet)
+{
+       enet_write(enet, ENET_DMA_CH_RX_CFG + ENET_DMA_CH_CFG_INT_MASK, ENET_DMA_INT_DEFAULTS);
+}
+
+static void bcm4908enet_intrs_off(struct bcm4908enet *enet)
+{
+       enet_write(enet, ENET_DMA_CH_RX_CFG + ENET_DMA_CH_CFG_INT_MASK, 0);
+}
+
+static void bcm4908enet_intrs_ack(struct bcm4908enet *enet)
+{
+       enet_write(enet, ENET_DMA_CH_RX_CFG + ENET_DMA_CH_CFG_INT_STAT, ENET_DMA_INT_DEFAULTS);
+}
+
+/***
+ * DMA
+ */
+
+static int bcm4908_dma_alloc_buf_descs(struct bcm4908enet *enet, struct bcm4908enet_dma_ring *ring)
+{
+       int size = ring->length * sizeof(struct bcm4908enet_dma_ring_bd);
+       struct device *dev = enet->dev;
+
+       ring->cpu_addr = dma_alloc_coherent(dev, size, &ring->dma_addr, GFP_KERNEL);
+       if (!ring->cpu_addr)
+               return -ENOMEM;
+
+       if (((uintptr_t)ring->cpu_addr) & (0x40 - 1)) {
+               dev_err(dev, "Invalid DMA ring alignment\n");
+               goto err_free_buf_descs;
+       }
+
+       ring->slots = kzalloc(ring->length * sizeof(*ring->slots), GFP_KERNEL);
+       if (!ring->slots)
+               goto err_free_buf_descs;
+
+       memset(ring->cpu_addr, 0, size);
+
+       ring->read_idx = 0;
+       ring->write_idx = 0;
+
+       return 0;
+
+err_free_buf_descs:
+       dma_free_coherent(dev, size, ring->cpu_addr, ring->dma_addr);
+       return -ENOMEM;
+}
+
+static void bcm4908enet_dma_free(struct bcm4908enet *enet)
+{
+       struct bcm4908enet_dma_ring *tx_ring = &enet->tx_ring;
+       struct bcm4908enet_dma_ring *rx_ring = &enet->rx_ring;
+       struct device *dev = enet->dev;
+       int size;
+
+       size = rx_ring->length * sizeof(struct bcm4908enet_dma_ring_bd);
+       if (rx_ring->cpu_addr)
+               dma_free_coherent(dev, size, rx_ring->cpu_addr, rx_ring->dma_addr);
+       kfree(rx_ring->slots);
+
+       size = tx_ring->length * sizeof(struct bcm4908enet_dma_ring_bd);
+       if (tx_ring->cpu_addr)
+               dma_free_coherent(dev, size, tx_ring->cpu_addr, tx_ring->dma_addr);
+       kfree(tx_ring->slots);
+}
+
+static int bcm4908enet_dma_alloc(struct bcm4908enet *enet)
+{
+       struct bcm4908enet_dma_ring *tx_ring = &enet->tx_ring;
+       struct bcm4908enet_dma_ring *rx_ring = &enet->rx_ring;
+       struct device *dev = enet->dev;
+       int err;
+
+       tx_ring->length = ENET_TX_BDS_NUM;
+       tx_ring->is_tx = 1;
+       tx_ring->cfg_block = ENET_DMA_CH_TX_CFG;
+       tx_ring->st_ram_block = ENET_DMA_CH_TX_STATE_RAM;
+       err = bcm4908_dma_alloc_buf_descs(enet, tx_ring);
+       if (err) {
+               dev_err(dev, "Failed to alloc TX buf descriptors: %d\n", err);
+               return err;
+       }
+
+       rx_ring->length = ENET_RX_BDS_NUM;
+       rx_ring->is_tx = 0;
+       rx_ring->cfg_block = ENET_DMA_CH_RX_CFG;
+       rx_ring->st_ram_block = ENET_DMA_CH_RX_STATE_RAM;
+       err = bcm4908_dma_alloc_buf_descs(enet, rx_ring);
+       if (err) {
+               dev_err(dev, "Failed to alloc RX buf descriptors: %d\n", err);
+               bcm4908enet_dma_free(enet);
+               return err;
+       }
+
+       return 0;
+}
+
+static void bcm4908enet_dma_reset(struct bcm4908enet *enet)
+{
+       struct bcm4908enet_dma_ring *rings[] = { &enet->rx_ring, &enet->tx_ring };
+       int i;
+
+       /* Disable the DMA controller and channel */
+       for (i = 0; i < ARRAY_SIZE(rings); i++)
+               enet_write(enet, rings[i]->cfg_block + ENET_DMA_CH_CFG, 0);
+       enet_maskset(enet, ENET_DMA_CONTROLLER_CFG, ENET_DMA_CTRL_CFG_MASTER_EN, 0);
+
+       /* Reset channels state */
+       for (i = 0; i < ARRAY_SIZE(rings); i++) {
+               struct bcm4908enet_dma_ring *ring = rings[i];
+
+               enet_write(enet, ring->st_ram_block + ENET_DMA_CH_STATE_RAM_BASE_DESC_PTR, 0);
+               enet_write(enet, ring->st_ram_block + ENET_DMA_CH_STATE_RAM_STATE_DATA, 0);
+               enet_write(enet, ring->st_ram_block + ENET_DMA_CH_STATE_RAM_DESC_LEN_STATUS, 0);
+               enet_write(enet, ring->st_ram_block + ENET_DMA_CH_STATE_RAM_DESC_BASE_BUFPTR, 0);
+       }
+}
+
+static int bcm4908enet_dma_alloc_rx_buf(struct bcm4908enet *enet, unsigned int idx)
+{
+       struct bcm4908enet_dma_ring_bd *buf_desc = &enet->rx_ring.buf_desc[idx];
+       struct bcm4908enet_dma_ring_slot *slot = &enet->rx_ring.slots[idx];
+       struct device *dev = enet->dev;
+       u32 tmp;
+       int err;
+
+       slot->len = ENET_MTU_MAX + ENET_MTU_MAX_EXTRA_SIZE;
+
+       slot->skb = netdev_alloc_skb(enet->netdev, slot->len);
+       if (!slot->skb)
+               return -ENOMEM;
+
+       slot->dma_addr = dma_map_single(dev, slot->skb->data, slot->len, DMA_FROM_DEVICE);
+       err = dma_mapping_error(dev, slot->dma_addr);
+       if (err) {
+               dev_err(dev, "Failed to map DMA buffer: %d\n", err);
+               kfree_skb(slot->skb);
+               slot->skb = NULL;
+               return err;
+       }
+
+       tmp = slot->len << DMA_CTL_LEN_DESC_BUFLENGTH_SHIFT;
+       tmp |= DMA_CTL_STATUS_OWN;
+       if (idx == enet->rx_ring.length - 1)
+               tmp |= DMA_CTL_STATUS_WRAP;
+       buf_desc->ctl = cpu_to_le32(tmp);
+       buf_desc->addr = cpu_to_le32(slot->dma_addr);
+
+       return 0;
+}
+
+static void bcm4908enet_dma_ring_init(struct bcm4908enet *enet,
+                                     struct bcm4908enet_dma_ring *ring)
+{
+       int reset_channel = 0; /* We support only 1 main channel (with TX and RX) */
+       int reset_subch = ring->is_tx ? 1 : 0;
+
+       /* Reset the DMA channel */
+       enet_write(enet, ENET_DMA_CTRL_CHANNEL_RESET, BIT(reset_channel * 2 + reset_subch));
+       enet_write(enet, ENET_DMA_CTRL_CHANNEL_RESET, 0);
+
+       enet_write(enet, ring->cfg_block + ENET_DMA_CH_CFG, 0);
+       enet_write(enet, ring->cfg_block + ENET_DMA_CH_CFG_MAX_BURST, ENET_DMA_MAX_BURST_LEN);
+       enet_write(enet, ring->cfg_block + ENET_DMA_CH_CFG_INT_MASK, 0);
+
+       enet_write(enet, ring->st_ram_block + ENET_DMA_CH_STATE_RAM_BASE_DESC_PTR,
+                  (uint32_t)ring->dma_addr);
+}
+
+static void bcm4908enet_dma_uninit(struct bcm4908enet *enet)
+{
+       struct bcm4908enet_dma_ring *rx_ring = &enet->rx_ring;
+       struct bcm4908enet_dma_ring_slot *slot;
+       struct device *dev = enet->dev;
+       int i;
+
+       for (i = rx_ring->length - 1; i >= 0; i--) {
+               slot = &rx_ring->slots[i];
+               if (!slot->skb)
+                       continue;
+               dma_unmap_single(dev, slot->dma_addr, slot->len, DMA_FROM_DEVICE);
+               kfree_skb(slot->skb);
+               slot->skb = NULL;
+       }
+}
+
+static int bcm4908enet_dma_init(struct bcm4908enet *enet)
+{
+       struct bcm4908enet_dma_ring *rx_ring = &enet->rx_ring;
+       struct device *dev = enet->dev;
+       int err;
+       int i;
+
+       for (i = 0; i < rx_ring->length; i++) {
+               err = bcm4908enet_dma_alloc_rx_buf(enet, i);
+               if (err) {
+                       dev_err(dev, "Failed to alloc RX buffer: %d\n", err);
+                       bcm4908enet_dma_uninit(enet);
+                       return err;
+               }
+       }
+
+       bcm4908enet_dma_ring_init(enet, &enet->tx_ring);
+       bcm4908enet_dma_ring_init(enet, &enet->rx_ring);
+
+       return 0;
+}
+
+static void bcm4908enet_dma_tx_ring_ensable(struct bcm4908enet *enet,
+                                           struct bcm4908enet_dma_ring *ring)
+{
+       enet_write(enet, ring->cfg_block + ENET_DMA_CH_CFG, ENET_DMA_CH_CFG_ENABLE);
+}
+
+static void bcm4908enet_dma_tx_ring_disable(struct bcm4908enet *enet,
+                                           struct bcm4908enet_dma_ring *ring)
+{
+       enet_write(enet, ring->cfg_block + ENET_DMA_CH_CFG, 0);
+}
+
+static void bcm4908enet_dma_rx_ring_enable(struct bcm4908enet *enet,
+                                          struct bcm4908enet_dma_ring *ring)
+{
+       enet_set(enet, ring->cfg_block + ENET_DMA_CH_CFG, ENET_DMA_CH_CFG_ENABLE);
+}
+
+static void bcm4908enet_dma_rx_ring_disable(struct bcm4908enet *enet,
+                                           struct bcm4908enet_dma_ring *ring)
+{
+       unsigned long deadline;
+       u32 tmp;
+
+       enet_maskset(enet, ring->cfg_block + ENET_DMA_CH_CFG, ENET_DMA_CH_CFG_ENABLE, 0);
+
+       deadline = jiffies + usecs_to_jiffies(2000);
+       do {
+               tmp = enet_read(enet, ring->cfg_block + ENET_DMA_CH_CFG);
+               if (!(tmp & ENET_DMA_CH_CFG_ENABLE))
+                       return;
+               enet_maskset(enet, ring->cfg_block + ENET_DMA_CH_CFG, ENET_DMA_CH_CFG_ENABLE, 0);
+               usleep_range(10, 30);
+       } while (!time_after_eq(jiffies, deadline));
+
+       dev_warn(enet->dev, "Timeout waiting for DMA TX stop\n");
+}
+
+/***
+ * Ethernet driver
+ */
+
+static void bcm4908enet_gmac_init(struct bcm4908enet *enet)
+{
+       u32 cmd;
+
+       cmd = enet_umac_read(enet, UMAC_CMD);
+       enet_umac_write(enet, UMAC_CMD, cmd | CMD_SW_RESET);
+       enet_umac_write(enet, UMAC_CMD, cmd & ~CMD_SW_RESET);
+
+       enet_set(enet, ENET_FLUSH, ENET_FLUSH_RXFIFO_FLUSH | ENET_FLUSH_TXFIFO_FLUSH);
+       enet_maskset(enet, ENET_FLUSH, ENET_FLUSH_RXFIFO_FLUSH | ENET_FLUSH_TXFIFO_FLUSH, 0);
+
+       enet_set(enet, ENET_MIB_CTRL, ENET_MIB_CTRL_CLR_MIB);
+       enet_maskset(enet, ENET_MIB_CTRL, ENET_MIB_CTRL_CLR_MIB, 0);
+
+       cmd = enet_umac_read(enet, UMAC_CMD);
+       cmd &= ~(CMD_SPEED_MASK << CMD_SPEED_SHIFT);
+       cmd &= ~CMD_TX_EN;
+       cmd &= ~CMD_RX_EN;
+       cmd |= CMD_SPEED_1000 << CMD_SPEED_SHIFT;
+       enet_umac_write(enet, UMAC_CMD, cmd);
+
+       enet_maskset(enet, ENET_GMAC_STATUS,
+                    ENET_GMAC_STATUS_ETH_SPEED_MASK |
+                    ENET_GMAC_STATUS_HD |
+                    ENET_GMAC_STATUS_AUTO_CFG_EN |
+                    ENET_GMAC_STATUS_LINK_UP,
+                    ENET_GMAC_STATUS_ETH_SPEED_1000 |
+                    ENET_GMAC_STATUS_AUTO_CFG_EN |
+                    ENET_GMAC_STATUS_LINK_UP);
+}
+
+static irqreturn_t bcm4908enet_irq_handler(int irq, void *dev_id)
+{
+       struct bcm4908enet *enet = dev_id;
+
+       bcm4908enet_intrs_off(enet);
+       bcm4908enet_intrs_ack(enet);
+
+       napi_schedule(&enet->napi);
+
+       return IRQ_HANDLED;
+}
+
+static int bcm4908enet_open(struct net_device *netdev)
+{
+       struct bcm4908enet *enet = netdev_priv(netdev);
+       struct device *dev = enet->dev;
+       int err;
+
+       err = request_irq(netdev->irq, bcm4908enet_irq_handler, 0, "enet", enet);
+       if (err) {
+               dev_err(dev, "Failed to request IRQ %d: %d\n", netdev->irq, err);
+               return err;
+       }
+
+       bcm4908enet_gmac_init(enet);
+       bcm4908enet_dma_reset(enet);
+       bcm4908enet_dma_init(enet);
+
+       enet_umac_set(enet, UMAC_CMD, CMD_TX_EN | CMD_RX_EN);
+
+       enet_set(enet, ENET_DMA_CONTROLLER_CFG, ENET_DMA_CTRL_CFG_MASTER_EN);
+       enet_maskset(enet, ENET_DMA_CONTROLLER_CFG, ENET_DMA_CTRL_CFG_FLOWC_CH1_EN, 0);
+       bcm4908enet_dma_rx_ring_enable(enet, &enet->rx_ring);
+
+       napi_enable(&enet->napi);
+       netif_carrier_on(netdev);
+       netif_start_queue(netdev);
+
+       bcm4908enet_intrs_ack(enet);
+       bcm4908enet_intrs_on(enet);
+
+       return 0;
+}
+
+static int bcm4908enet_stop(struct net_device *netdev)
+{
+       struct bcm4908enet *enet = netdev_priv(netdev);
+
+       netif_stop_queue(netdev);
+       netif_carrier_off(netdev);
+       napi_disable(&enet->napi);
+
+       bcm4908enet_dma_rx_ring_disable(enet, &enet->rx_ring);
+       bcm4908enet_dma_tx_ring_disable(enet, &enet->tx_ring);
+
+       bcm4908enet_dma_uninit(enet);
+
+       free_irq(enet->netdev->irq, enet);
+
+       return 0;
+}
+
+static int bcm4908enet_start_xmit(struct sk_buff *skb, struct net_device *netdev)
+{
+       struct bcm4908enet *enet = netdev_priv(netdev);
+       struct bcm4908enet_dma_ring *ring = &enet->tx_ring;
+       struct bcm4908enet_dma_ring_slot *slot;
+       struct device *dev = enet->dev;
+       struct bcm4908enet_dma_ring_bd *buf_desc;
+       int free_buf_descs;
+       u32 tmp;
+
+       /* Free transmitted skbs */
+       while (ring->read_idx != ring->write_idx) {
+               buf_desc = &ring->buf_desc[ring->read_idx];
+               if (buf_desc->ctl & DMA_CTL_STATUS_OWN)
+                       break;
+               slot = &ring->slots[ring->read_idx];
+
+               dma_unmap_single(dev, slot->dma_addr, slot->len, DMA_TO_DEVICE);
+               dev_kfree_skb(slot->skb);
+               if (++ring->read_idx == ring->length)
+                       ring->read_idx = 0;
+       }
+
+       /* Don't use the last empty buf descriptor */
+       if (ring->read_idx <= ring->write_idx)
+               free_buf_descs = ring->read_idx - ring->write_idx + ring->length;
+       else
+               free_buf_descs = ring->read_idx - ring->write_idx;
+       if (free_buf_descs < 2)
+               return NETDEV_TX_BUSY;
+
+       /* Hardware removes OWN bit after sending data */
+       buf_desc = &ring->buf_desc[ring->write_idx];
+       if (unlikely(le32_to_cpu(buf_desc->ctl) & DMA_CTL_STATUS_OWN)) {
+               netif_stop_queue(netdev);
+               return NETDEV_TX_BUSY;
+       }
+
+       slot = &ring->slots[ring->write_idx];
+       slot->skb = skb;
+       slot->len = skb->len;
+       slot->dma_addr = dma_map_single(dev, skb->data, skb->len, DMA_TO_DEVICE);
+       if (unlikely(dma_mapping_error(dev, slot->dma_addr)))
+               return NETDEV_TX_BUSY;
+
+       tmp = skb->len << DMA_CTL_LEN_DESC_BUFLENGTH_SHIFT;
+       tmp |= DMA_CTL_STATUS_OWN;
+       tmp |= DMA_CTL_STATUS_SOP;
+       tmp |= DMA_CTL_STATUS_EOP;
+       tmp |= DMA_CTL_STATUS_APPEND_CRC;
+       if (ring->write_idx + 1 == ring->length - 1)
+               tmp |= DMA_CTL_STATUS_WRAP;
+
+       buf_desc->addr = cpu_to_le32((uint32_t)slot->dma_addr);
+       buf_desc->ctl = cpu_to_le32(tmp);
+
+       bcm4908enet_dma_tx_ring_ensable(enet, &enet->tx_ring);
+
+       if (++ring->write_idx == ring->length - 1)
+               ring->write_idx = 0;
+       enet->netdev->stats.tx_bytes += skb->len;
+       enet->netdev->stats.tx_packets++;
+
+       return NETDEV_TX_OK;
+}
+
+static int bcm4908enet_poll(struct napi_struct *napi, int weight)
+{
+       struct bcm4908enet *enet = container_of(napi, struct bcm4908enet, napi);
+       struct device *dev = enet->dev;
+       int handled = 0;
+
+       while (handled < weight) {
+               struct bcm4908enet_dma_ring_bd *buf_desc;
+               struct bcm4908enet_dma_ring_slot slot;
+               u32 ctl;
+               int len;
+               int err;
+
+               buf_desc = &enet->rx_ring.buf_desc[enet->rx_ring.read_idx];
+               ctl = le32_to_cpu(buf_desc->ctl);
+               if (ctl & DMA_CTL_STATUS_OWN)
+                       break;
+
+               slot = enet->rx_ring.slots[enet->rx_ring.read_idx];
+
+               /* Provide new buffer before unpinning the old one */
+               err = bcm4908enet_dma_alloc_rx_buf(enet, enet->rx_ring.read_idx);
+               if (err)
+                       break;
+
+               if (++enet->rx_ring.read_idx == enet->rx_ring.length)
+                       enet->rx_ring.read_idx = 0;
+
+               len = (ctl & DMA_CTL_LEN_DESC_BUFLENGTH) >> DMA_CTL_LEN_DESC_BUFLENGTH_SHIFT;
+
+               if (len < ENET_MTU_MIN ||
+                   (ctl & (DMA_CTL_STATUS_SOP | DMA_CTL_STATUS_EOP)) != (DMA_CTL_STATUS_SOP | DMA_CTL_STATUS_EOP)) {
+                       enet->netdev->stats.rx_dropped++;
+                       break;
+               }
+
+               dma_unmap_single(dev, slot.dma_addr, slot.len, DMA_FROM_DEVICE);
+
+               skb_put(slot.skb, len - 4 + 2);
+               slot.skb->protocol = eth_type_trans(slot.skb, enet->netdev);
+               netif_receive_skb(slot.skb);
+
+               enet->netdev->stats.rx_packets++;
+               enet->netdev->stats.rx_bytes += len;
+       }
+
+       if (handled < weight) {
+               napi_complete_done(napi, handled);
+               bcm4908enet_intrs_on(enet);
+       }
+
+       return handled;
+}
+
+static const struct net_device_ops bcm96xx_netdev_ops = {
+       .ndo_open = bcm4908enet_open,
+       .ndo_stop = bcm4908enet_stop,
+       .ndo_start_xmit = bcm4908enet_start_xmit,
+       .ndo_set_mac_address = eth_mac_addr,
+};
+
+static int bcm4908enet_probe(struct platform_device *pdev)
+{
+       struct device *dev = &pdev->dev;
+       struct net_device *netdev;
+       struct bcm4908enet *enet;
+       int err;
+
+       netdev = devm_alloc_etherdev(dev, sizeof(*enet));
+       if (!netdev)
+               return -ENOMEM;
+
+       enet = netdev_priv(netdev);
+       enet->dev = dev;
+       enet->netdev = netdev;
+
+       enet->base = devm_platform_ioremap_resource(pdev, 0);
+       if (IS_ERR(enet->base)) {
+               dev_err(dev, "Failed to map registers: %ld\n", PTR_ERR(enet->base));
+               return PTR_ERR(enet->base);
+       }
+
+       netdev->irq = platform_get_irq_byname(pdev, "rx");
+       if (netdev->irq < 0)
+               return netdev->irq;
+
+       dma_set_coherent_mask(dev, DMA_BIT_MASK(32));
+
+       err = bcm4908enet_dma_alloc(enet);
+       if (err)
+               return err;
+
+       SET_NETDEV_DEV(netdev, &pdev->dev);
+       eth_hw_addr_random(netdev);
+       netdev->netdev_ops = &bcm96xx_netdev_ops;
+       netdev->min_mtu = ETH_ZLEN;
+       netdev->mtu = ENET_MTU_MAX;
+       netdev->max_mtu = ENET_MTU_MAX;
+       netif_napi_add(netdev, &enet->napi, bcm4908enet_poll, 64);
+
+       err = register_netdev(netdev);
+       if (err) {
+               bcm4908enet_dma_free(enet);
+               return err;
+       }
+
+       platform_set_drvdata(pdev, enet);
+
+       return 0;
+}
+
+static int bcm4908enet_remove(struct platform_device *pdev)
+{
+       struct bcm4908enet *enet = platform_get_drvdata(pdev);
+
+       unregister_netdev(enet->netdev);
+       netif_napi_del(&enet->napi);
+       bcm4908enet_dma_free(enet);
+
+       return 0;
+}
+
+static const struct of_device_id bcm4908enet_of_match[] = {
+       { .compatible = "brcm,bcm4908enet"},
+       {},
+};
+
+static struct platform_driver bcm4908enet_driver = {
+       .driver = {
+               .name = "bcm4908enet",
+               .of_match_table = bcm4908enet_of_match,
+       },
+       .probe  = bcm4908enet_probe,
+       .remove = bcm4908enet_remove,
+};
+module_platform_driver(bcm4908enet_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DEVICE_TABLE(of, bcm4908enet_of_match);
diff --git a/drivers/net/ethernet/broadcom/bcm4908enet.h b/drivers/net/ethernet/broadcom/bcm4908enet.h
new file mode 100644 (file)
index 0000000..11aadf0
--- /dev/null
@@ -0,0 +1,96 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef __BCM4908ENET_H
+#define __BCM4908ENET_H
+
+#define ENET_CONTROL                                   0x000
+#define ENET_MIB_CTRL                                  0x004
+#define  ENET_MIB_CTRL_CLR_MIB                         0x00000001
+#define ENET_RX_ERR_MASK                               0x008
+#define ENET_MIB_MAX_PKT_SIZE                          0x00C
+#define  ENET_MIB_MAX_PKT_SIZE_VAL                     0x00003fff
+#define ENET_DIAG_OUT                                  0x01c
+#define ENET_ENABLE_DROP_PKT                           0x020
+#define ENET_IRQ_ENABLE                                        0x024
+#define  ENET_IRQ_ENABLE_OVFL                          0x00000001
+#define ENET_GMAC_STATUS                               0x028
+#define  ENET_GMAC_STATUS_ETH_SPEED_MASK               0x00000003
+#define  ENET_GMAC_STATUS_ETH_SPEED_10                 0x00000000
+#define  ENET_GMAC_STATUS_ETH_SPEED_100                        0x00000001
+#define  ENET_GMAC_STATUS_ETH_SPEED_1000               0x00000002
+#define  ENET_GMAC_STATUS_HD                           0x00000004
+#define  ENET_GMAC_STATUS_AUTO_CFG_EN                  0x00000008
+#define  ENET_GMAC_STATUS_LINK_UP                      0x00000010
+#define ENET_IRQ_STATUS                                        0x02c
+#define  ENET_IRQ_STATUS_OVFL                          0x00000001
+#define ENET_OVERFLOW_COUNTER                          0x030
+#define ENET_FLUSH                                     0x034
+#define  ENET_FLUSH_RXFIFO_FLUSH                       0x00000001
+#define  ENET_FLUSH_TXFIFO_FLUSH                       0x00000002
+#define ENET_RSV_SELECT                                        0x038
+#define ENET_BP_FORCE                                  0x03c
+#define  ENET_BP_FORCE_FORCE                           0x00000001
+#define ENET_DMA_RX_OK_TO_SEND_COUNT                   0x040
+#define  ENET_DMA_RX_OK_TO_SEND_COUNT_VAL              0x0000000f
+#define ENET_TX_CRC_CTRL                               0x044
+#define ENET_MIB                                       0x200
+#define ENET_UNIMAC                                    0x400
+#define ENET_DMA                                       0x800
+#define ENET_DMA_CONTROLLER_CFG                                0x800
+#define  ENET_DMA_CTRL_CFG_MASTER_EN                   0x00000001
+#define  ENET_DMA_CTRL_CFG_FLOWC_CH1_EN                        0x00000002
+#define  ENET_DMA_CTRL_CFG_FLOWC_CH3_EN                        0x00000004
+#define ENET_DMA_FLOWCTL_CH1_THRESH_LO                 0x804
+#define ENET_DMA_FLOWCTL_CH1_THRESH_HI                 0x808
+#define ENET_DMA_FLOWCTL_CH1_ALLOC                     0x80c
+#define  ENET_DMA_FLOWCTL_CH1_ALLOC_FORCE              0x80000000
+#define ENET_DMA_FLOWCTL_CH3_THRESH_LO                 0x810
+#define ENET_DMA_FLOWCTL_CH3_THRESH_HI                 0x814
+#define ENET_DMA_FLOWCTL_CH3_ALLOC                     0x818
+#define ENET_DMA_FLOWCTL_CH5_THRESH_LO                 0x81C
+#define ENET_DMA_FLOWCTL_CH5_THRESH_HI                 0x820
+#define ENET_DMA_FLOWCTL_CH5_ALLOC                     0x824
+#define ENET_DMA_FLOWCTL_CH7_THRESH_LO                 0x828
+#define ENET_DMA_FLOWCTL_CH7_THRESH_HI                 0x82C
+#define ENET_DMA_FLOWCTL_CH7_ALLOC                     0x830
+#define ENET_DMA_CTRL_CHANNEL_RESET                    0x834
+#define ENET_DMA_CTRL_CHANNEL_DEBUG                    0x838
+#define ENET_DMA_CTRL_GLOBAL_INTERRUPT_STATUS          0x840
+#define ENET_DMA_CTRL_GLOBAL_INTERRUPT_MASK            0x844
+#define ENET_DMA_CH0_CFG                               0xa00           /* RX */
+#define ENET_DMA_CH1_CFG                               0xa10           /* TX */
+#define ENET_DMA_CH0_STATE_RAM                         0xc00           /* RX */
+#define ENET_DMA_CH1_STATE_RAM                         0xc10           /* TX */
+
+#define ENET_DMA_CH_CFG                                        0x00            /* assorted configuration */
+#define  ENET_DMA_CH_CFG_ENABLE                                0x00000001      /* set to enable channel */
+#define  ENET_DMA_CH_CFG_PKT_HALT                      0x00000002      /* idle after an EOP flag is detected */
+#define  ENET_DMA_CH_CFG_BURST_HALT                    0x00000004      /* idle after finish current memory burst */
+#define ENET_DMA_CH_CFG_INT_STAT                       0x04            /* interrupts control and status */
+#define ENET_DMA_CH_CFG_INT_MASK                       0x08            /* interrupts mask */
+#define  ENET_DMA_CH_CFG_INT_BUFF_DONE                 0x00000001      /* buffer done */
+#define  ENET_DMA_CH_CFG_INT_DONE                      0x00000002      /* packet xfer complete */
+#define  ENET_DMA_CH_CFG_INT_NO_DESC                   0x00000004      /* no valid descriptors */
+#define  ENET_DMA_CH_CFG_INT_RX_ERROR                  0x00000008      /* rxdma detect client protocol error */
+#define ENET_DMA_CH_CFG_MAX_BURST                      0x0c            /* max burst length permitted */
+#define  ENET_DMA_CH_CFG_MAX_BURST_DESCSIZE_SEL                0x00040000      /* DMA Descriptor Size Selection */
+#define ENET_DMA_CH_CFG_SIZE                           0x10
+
+#define ENET_DMA_CH_STATE_RAM_BASE_DESC_PTR            0x00            /* descriptor ring start address */
+#define ENET_DMA_CH_STATE_RAM_STATE_DATA               0x04            /* state/bytes done/ring offset */
+#define ENET_DMA_CH_STATE_RAM_DESC_LEN_STATUS          0x08            /* buffer descriptor status and len */
+#define ENET_DMA_CH_STATE_RAM_DESC_BASE_BUFPTR         0x0c            /* buffer descrpitor current processing */
+#define ENET_DMA_CH_STATE_RAM_SIZE                     0x10
+
+#define DMA_CTL_STATUS_APPEND_CRC                      0x00000100
+#define DMA_CTL_STATUS_APPEND_BRCM_TAG                 0x00000200
+#define DMA_CTL_STATUS_PRIO                            0x00000C00  /* Prio for Tx */
+#define DMA_CTL_STATUS_WRAP                            0x00001000  /* */
+#define DMA_CTL_STATUS_SOP                             0x00002000  /* first buffer in packet */
+#define DMA_CTL_STATUS_EOP                             0x00004000  /* last buffer in packet */
+#define DMA_CTL_STATUS_OWN                             0x00008000  /* cleared by DMA, set by SW */
+#define DMA_CTL_LEN_DESC_BUFLENGTH                     0x0fff0000
+#define DMA_CTL_LEN_DESC_BUFLENGTH_SHIFT               16
+#define DMA_CTL_LEN_DESC_MULTICAST                     0x40000000
+#define DMA_CTL_LEN_DESC_USEFPM                                0x80000000
+
+#endif