Commit ee7da21a authored by Joel Stanley's avatar Joel Stanley Committed by David S. Miller

net: Add driver for LiteX's LiteETH network interface

LiteX is a soft system-on-chip that targets FPGAs. LiteETH is a basic
network device that is commonly used in LiteX designs.

The driver was first written in 2017 and has been maintained by the
LiteX community in various trees. Thank you to all who have contributed.
Co-developed-by: default avatarGabriel Somlo <gsomlo@gmail.com>
Co-developed-by: default avatarDavid Shah <dave@ds0.me>
Co-developed-by: default avatarStafford Horne <shorne@gmail.com>
Signed-off-by: default avatarJoel Stanley <joel@jms.id.au>
Tested-by: default avatarGabriel Somlo <gsomlo@gmail.com>
Reviewed-by: default avatarGabriel Somlo <gsomlo@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent b0f8d307
......@@ -118,6 +118,7 @@ config LANTIQ_XRX200
Support for the PMAC of the Gigabit switch (GSWIP) inside the
Lantiq / Intel VRX200 VDSL SoC
source "drivers/net/ethernet/litex/Kconfig"
source "drivers/net/ethernet/marvell/Kconfig"
source "drivers/net/ethernet/mediatek/Kconfig"
source "drivers/net/ethernet/mellanox/Kconfig"
......
......@@ -51,6 +51,7 @@ obj-$(CONFIG_JME) += jme.o
obj-$(CONFIG_KORINA) += korina.o
obj-$(CONFIG_LANTIQ_ETOP) += lantiq_etop.o
obj-$(CONFIG_LANTIQ_XRX200) += lantiq_xrx200.o
obj-$(CONFIG_NET_VENDOR_LITEX) += litex/
obj-$(CONFIG_NET_VENDOR_MARVELL) += marvell/
obj-$(CONFIG_NET_VENDOR_MEDIATEK) += mediatek/
obj-$(CONFIG_NET_VENDOR_MELLANOX) += mellanox/
......
#
# LiteX device configuration
#
config NET_VENDOR_LITEX
bool "LiteX devices"
default y
help
If you have a network (Ethernet) card belonging to this class, say Y.
Note that the answer to this question doesn't directly affect the
kernel: saying N will just cause the configurator to skip all
the questions about LiteX devices. If you say Y, you will be asked
for your specific card in the following questions.
if NET_VENDOR_LITEX
config LITEX_LITEETH
tristate "LiteX Ethernet support"
help
If you wish to compile a kernel for hardware with a LiteX LiteEth
device then you should answer Y to this.
LiteX is a soft system-on-chip that targets FPGAs. LiteETH is a basic
network device that is commonly used in LiteX designs.
endif # NET_VENDOR_LITEX
#
# Makefile for the LiteX network device drivers.
#
obj-$(CONFIG_LITEX_LITEETH) += litex_liteeth.o
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* LiteX Liteeth Ethernet
*
* Copyright 2017 Joel Stanley <joel@jms.id.au>
*
*/
#include <linux/etherdevice.h>
#include <linux/interrupt.h>
#include <linux/litex.h>
#include <linux/module.h>
#include <linux/of_net.h>
#include <linux/platform_device.h>
#define LITEETH_WRITER_SLOT 0x00
#define LITEETH_WRITER_LENGTH 0x04
#define LITEETH_WRITER_ERRORS 0x08
#define LITEETH_WRITER_EV_STATUS 0x0C
#define LITEETH_WRITER_EV_PENDING 0x10
#define LITEETH_WRITER_EV_ENABLE 0x14
#define LITEETH_READER_START 0x18
#define LITEETH_READER_READY 0x1C
#define LITEETH_READER_LEVEL 0x20
#define LITEETH_READER_SLOT 0x24
#define LITEETH_READER_LENGTH 0x28
#define LITEETH_READER_EV_STATUS 0x2C
#define LITEETH_READER_EV_PENDING 0x30
#define LITEETH_READER_EV_ENABLE 0x34
#define LITEETH_PREAMBLE_CRC 0x38
#define LITEETH_PREAMBLE_ERRORS 0x3C
#define LITEETH_CRC_ERRORS 0x40
#define LITEETH_PHY_CRG_RESET 0x00
#define LITEETH_MDIO_W 0x04
#define LITEETH_MDIO_R 0x0C
#define DRV_NAME "liteeth"
struct liteeth {
void __iomem *base;
struct net_device *netdev;
struct device *dev;
u32 slot_size;
/* Tx */
u32 tx_slot;
u32 num_tx_slots;
void __iomem *tx_base;
/* Rx */
u32 rx_slot;
u32 num_rx_slots;
void __iomem *rx_base;
};
static int liteeth_rx(struct net_device *netdev)
{
struct liteeth *priv = netdev_priv(netdev);
struct sk_buff *skb;
unsigned char *data;
u8 rx_slot;
int len;
rx_slot = litex_read8(priv->base + LITEETH_WRITER_SLOT);
len = litex_read32(priv->base + LITEETH_WRITER_LENGTH);
if (len == 0 || len > 2048)
goto rx_drop;
skb = netdev_alloc_skb_ip_align(netdev, len);
if (!skb) {
netdev_err(netdev, "couldn't get memory\n");
goto rx_drop;
}
data = skb_put(skb, len);
memcpy_fromio(data, priv->rx_base + rx_slot * priv->slot_size, len);
skb->protocol = eth_type_trans(skb, netdev);
netdev->stats.rx_packets++;
netdev->stats.rx_bytes += len;
return netif_rx(skb);
rx_drop:
netdev->stats.rx_dropped++;
netdev->stats.rx_errors++;
return NET_RX_DROP;
}
static irqreturn_t liteeth_interrupt(int irq, void *dev_id)
{
struct net_device *netdev = dev_id;
struct liteeth *priv = netdev_priv(netdev);
u8 reg;
reg = litex_read8(priv->base + LITEETH_READER_EV_PENDING);
if (reg) {
if (netif_queue_stopped(netdev))
netif_wake_queue(netdev);
litex_write8(priv->base + LITEETH_READER_EV_PENDING, reg);
}
reg = litex_read8(priv->base + LITEETH_WRITER_EV_PENDING);
if (reg) {
liteeth_rx(netdev);
litex_write8(priv->base + LITEETH_WRITER_EV_PENDING, reg);
}
return IRQ_HANDLED;
}
static int liteeth_open(struct net_device *netdev)
{
struct liteeth *priv = netdev_priv(netdev);
int err;
/* Clear pending events */
litex_write8(priv->base + LITEETH_WRITER_EV_PENDING, 1);
litex_write8(priv->base + LITEETH_READER_EV_PENDING, 1);
err = request_irq(netdev->irq, liteeth_interrupt, 0, netdev->name, netdev);
if (err) {
netdev_err(netdev, "failed to request irq %d\n", netdev->irq);
return err;
}
/* Enable IRQs */
litex_write8(priv->base + LITEETH_WRITER_EV_ENABLE, 1);
litex_write8(priv->base + LITEETH_READER_EV_ENABLE, 1);
netif_carrier_on(netdev);
netif_start_queue(netdev);
return 0;
}
static int liteeth_stop(struct net_device *netdev)
{
struct liteeth *priv = netdev_priv(netdev);
netif_stop_queue(netdev);
netif_carrier_off(netdev);
litex_write8(priv->base + LITEETH_WRITER_EV_ENABLE, 0);
litex_write8(priv->base + LITEETH_READER_EV_ENABLE, 0);
free_irq(netdev->irq, netdev);
return 0;
}
static int liteeth_start_xmit(struct sk_buff *skb, struct net_device *netdev)
{
struct liteeth *priv = netdev_priv(netdev);
void __iomem *txbuffer;
if (!litex_read8(priv->base + LITEETH_READER_READY)) {
if (net_ratelimit())
netdev_err(netdev, "LITEETH_READER_READY not ready\n");
netif_stop_queue(netdev);
return NETDEV_TX_BUSY;
}
/* Reject oversize packets */
if (unlikely(skb->len > priv->slot_size)) {
if (net_ratelimit())
netdev_err(netdev, "tx packet too big\n");
dev_kfree_skb_any(skb);
netdev->stats.tx_dropped++;
netdev->stats.tx_errors++;
return NETDEV_TX_OK;
}
txbuffer = priv->tx_base + priv->tx_slot * priv->slot_size;
memcpy_toio(txbuffer, skb->data, skb->len);
litex_write8(priv->base + LITEETH_READER_SLOT, priv->tx_slot);
litex_write16(priv->base + LITEETH_READER_LENGTH, skb->len);
litex_write8(priv->base + LITEETH_READER_START, 1);
netdev->stats.tx_bytes += skb->len;
netdev->stats.tx_packets++;
priv->tx_slot = (priv->tx_slot + 1) % priv->num_tx_slots;
dev_kfree_skb_any(skb);
return NETDEV_TX_OK;
}
static const struct net_device_ops liteeth_netdev_ops = {
.ndo_open = liteeth_open,
.ndo_stop = liteeth_stop,
.ndo_start_xmit = liteeth_start_xmit,
};
static void liteeth_setup_slots(struct liteeth *priv)
{
struct device_node *np = priv->dev->of_node;
int err;
err = of_property_read_u32(np, "litex,rx-slots", &priv->num_rx_slots);
if (err) {
dev_dbg(priv->dev, "unable to get litex,rx-slots, using 2\n");
priv->num_rx_slots = 2;
}
err = of_property_read_u32(np, "litex,tx-slots", &priv->num_tx_slots);
if (err) {
dev_dbg(priv->dev, "unable to get litex,tx-slots, using 2\n");
priv->num_tx_slots = 2;
}
err = of_property_read_u32(np, "litex,slot-size", &priv->slot_size);
if (err) {
dev_dbg(priv->dev, "unable to get litex,slot-size, using 0x800\n");
priv->slot_size = 0x800;
}
}
static int liteeth_probe(struct platform_device *pdev)
{
struct net_device *netdev;
void __iomem *buf_base;
struct resource *res;
struct liteeth *priv;
int irq, err;
netdev = devm_alloc_etherdev(&pdev->dev, sizeof(*priv));
if (!netdev)
return -ENOMEM;
SET_NETDEV_DEV(netdev, &pdev->dev);
platform_set_drvdata(pdev, netdev);
priv = netdev_priv(netdev);
priv->netdev = netdev;
priv->dev = &pdev->dev;
irq = platform_get_irq(pdev, 0);
if (irq < 0) {
dev_err(&pdev->dev, "Failed to get IRQ %d\n", irq);
return irq;
}
netdev->irq = irq;
res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "mac");
priv->base = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(priv->base))
return PTR_ERR(priv->base);
res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "buffer");
buf_base = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(buf_base))
return PTR_ERR(buf_base);
liteeth_setup_slots(priv);
/* Rx slots */
priv->rx_base = buf_base;
priv->rx_slot = 0;
/* Tx slots come after Rx slots */
priv->tx_base = buf_base + priv->num_rx_slots * priv->slot_size;
priv->tx_slot = 0;
err = of_get_mac_address(pdev->dev.of_node, netdev->dev_addr);
if (err)
eth_hw_addr_random(netdev);
netdev->netdev_ops = &liteeth_netdev_ops;
err = register_netdev(netdev);
if (err) {
dev_err(&pdev->dev, "Failed to register netdev %d\n", err);
return err;
}
netdev_info(netdev, "irq %d slots: tx %d rx %d size %d\n",
netdev->irq, priv->num_tx_slots, priv->num_rx_slots, priv->slot_size);
return 0;
}
static int liteeth_remove(struct platform_device *pdev)
{
struct net_device *netdev = platform_get_drvdata(pdev);
unregister_netdev(netdev);
free_netdev(netdev);
return 0;
}
static const struct of_device_id liteeth_of_match[] = {
{ .compatible = "litex,liteeth" },
{ }
};
MODULE_DEVICE_TABLE(of, liteeth_of_match);
static struct platform_driver liteeth_driver = {
.probe = liteeth_probe,
.remove = liteeth_remove,
.driver = {
.name = DRV_NAME,
.of_match_table = liteeth_of_match,
},
};
module_platform_driver(liteeth_driver);
MODULE_AUTHOR("Joel Stanley <joel@jms.id.au>");
MODULE_LICENSE("GPL");
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