Hi Joel, Thanks for pushing this upstream (and for writing it to begin with)! Would you mind diff-ing your version of litex_liteeth.c against what is currently in https://github.com/litex-hub/linux/blob/litex-rebase/drivers/net/ethernet/litex/litex_liteeth.c ? Two main differences we should discuss: 1. there's a polling mode (added by Antony Pavlov), and if we decide *not* to keep it around, I want to ensure we do that deliberately, with an explanation as to why; 2. LiteX CSRs are accessed using `litex_[read|write][8|16|32]()` as opposed to simply `[read|write][b|w|l]()`. The former set are defined in `include/linux/litex.h` and are needed to ensure correct accesses regardless of endianness, since by default LiteX registers' endianness mirrors that of the configured CPU. Thanks much, --Gabriel On Fri, Aug 06, 2021 at 03:19:04PM +0930, Joel Stanley wrote: > 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: Gabriel Somlo <gsomlo@xxxxxxxxx> > Co-developed-by: David Shah <dave@xxxxxx> > Co-developed-by: Stafford Horne <shorne@xxxxxxxxx> > Signed-off-by: Joel Stanley <joel@xxxxxxxxx> > --- > drivers/net/ethernet/Kconfig | 1 + > drivers/net/ethernet/Makefile | 1 + > drivers/net/ethernet/litex/Kconfig | 24 ++ > drivers/net/ethernet/litex/Makefile | 5 + > drivers/net/ethernet/litex/litex_liteeth.c | 340 +++++++++++++++++++++ > 5 files changed, 371 insertions(+) > create mode 100644 drivers/net/ethernet/litex/Kconfig > create mode 100644 drivers/net/ethernet/litex/Makefile > create mode 100644 drivers/net/ethernet/litex/litex_liteeth.c > > diff --git a/drivers/net/ethernet/Kconfig b/drivers/net/ethernet/Kconfig > index 1cdff1dca790..d796684ec9ca 100644 > --- a/drivers/net/ethernet/Kconfig > +++ b/drivers/net/ethernet/Kconfig > @@ -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" > diff --git a/drivers/net/ethernet/Makefile b/drivers/net/ethernet/Makefile > index cb3f9084a21b..aaa5078cd7d1 100644 > --- a/drivers/net/ethernet/Makefile > +++ b/drivers/net/ethernet/Makefile > @@ -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/ > diff --git a/drivers/net/ethernet/litex/Kconfig b/drivers/net/ethernet/litex/Kconfig > new file mode 100644 > index 000000000000..0a863e3ff7bf > --- /dev/null > +++ b/drivers/net/ethernet/litex/Kconfig > @@ -0,0 +1,24 @@ > +# > +# 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. > + > +endif # NET_VENDOR_LITEX > diff --git a/drivers/net/ethernet/litex/Makefile b/drivers/net/ethernet/litex/Makefile > new file mode 100644 > index 000000000000..9343b73b8e49 > --- /dev/null > +++ b/drivers/net/ethernet/litex/Makefile > @@ -0,0 +1,5 @@ > +# > +# Makefile for the LiteX network device drivers. > +# > + > +obj-$(CONFIG_LITEX_LITEETH) += litex_liteeth.o > diff --git a/drivers/net/ethernet/litex/litex_liteeth.c b/drivers/net/ethernet/litex/litex_liteeth.c > new file mode 100644 > index 000000000000..48b551e6d97b > --- /dev/null > +++ b/drivers/net/ethernet/litex/litex_liteeth.c > @@ -0,0 +1,340 @@ > +// SPDX-License-Identifier: GPL-2.0-or-later > +/* > + * LiteX Liteeth Ethernet > + * > + * Copyright 2017 Joel Stanley <joel@xxxxxxxxx> > + * > + */ > + > +#include <linux/etherdevice.h> > +#include <linux/interrupt.h> > +#include <linux/module.h> > +#include <linux/of.h> > +#include <linux/of_net.h> > +#include <linux/of_address.h> > +#include <linux/phy.h> > +#include <linux/platform_device.h> > +#include <linux/iopoll.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" > + > +#define LITEETH_BUFFER_SIZE 0x800 > +#define MAX_PKT_SIZE LITEETH_BUFFER_SIZE > + > +struct liteeth { > + void __iomem *base; > + void __iomem *mdio_base; > + struct net_device *netdev; > + struct device *dev; > + struct mii_bus *mii_bus; > + > + /* Link management */ > + int cur_duplex; > + int cur_speed; > + > + /* Tx */ > + int tx_slot; > + int num_tx_slots; > + void __iomem *tx_base; > + > + /* Rx */ > + int rx_slot; > + int 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 = readb(priv->base + LITEETH_WRITER_SLOT); > + len = readl(priv->base + LITEETH_WRITER_LENGTH); > + > + skb = netdev_alloc_skb(netdev, len + NET_IP_ALIGN); > + if (!skb) { > + netdev_err(netdev, "couldn't get memory"); > + netdev->stats.rx_dropped++; > + return NET_RX_DROP; > + } > + > + /* Ensure alignemnt of the ip header within the skb */ > + skb_reserve(skb, NET_IP_ALIGN); > + if (len == 0 || len > 2048) > + return NET_RX_DROP; > + data = skb_put(skb, len); > + memcpy_fromio(data, priv->rx_base + rx_slot * LITEETH_BUFFER_SIZE, len); > + skb->protocol = eth_type_trans(skb, netdev); > + > + netdev->stats.rx_packets++; > + netdev->stats.rx_bytes += len; > + > + return netif_rx(skb); > +} > + > +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 = readb(priv->base + LITEETH_READER_EV_PENDING); > + if (reg) { > + netdev->stats.tx_packets++; > + writeb(reg, priv->base + LITEETH_READER_EV_PENDING); > + } > + > + reg = readb(priv->base + LITEETH_WRITER_EV_PENDING); > + if (reg) { > + liteeth_rx(netdev); > + writeb(reg, priv->base + LITEETH_WRITER_EV_PENDING); > + } > + > + return IRQ_HANDLED; > +} > + > +static int liteeth_open(struct net_device *netdev) > +{ > + struct liteeth *priv = netdev_priv(netdev); > + int err; > + > + /* Clear pending events */ > + writeb(1, priv->base + LITEETH_WRITER_EV_PENDING); > + writeb(1, priv->base + LITEETH_READER_EV_PENDING); > + > + 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 */ > + writeb(1, priv->base + LITEETH_WRITER_EV_ENABLE); > + writeb(1, priv->base + LITEETH_READER_EV_ENABLE); > + > + /* TODO: Remove these once we have working mdio support */ > + priv->cur_duplex = DUPLEX_FULL; > + priv->cur_speed = SPEED_100; > + 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); > + > + writeb(0, priv->base + LITEETH_WRITER_EV_ENABLE); > + writeb(0, priv->base + LITEETH_READER_EV_ENABLE); > + > + 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; > + int ret; > + u8 val; > + > + /* Reject oversize packets */ > + if (unlikely(skb->len > MAX_PKT_SIZE)) { > + if (net_ratelimit()) > + netdev_dbg(netdev, "tx packet too big\n"); > + goto drop; > + } > + > + txbuffer = priv->tx_base + priv->tx_slot * LITEETH_BUFFER_SIZE; > + memcpy_toio(txbuffer, skb->data, skb->len); > + writeb(priv->tx_slot, priv->base + LITEETH_READER_SLOT); > + writew(skb->len, priv->base + LITEETH_READER_LENGTH); > + > + ret = readl_poll_timeout_atomic(priv->base + LITEETH_READER_READY, val, val, 5, 1000); > + if (ret == -ETIMEDOUT) { > + netdev_err(netdev, "LITEETH_READER_READY timed out\n"); > + goto drop; > + } > + > + writeb(1, priv->base + LITEETH_READER_START); > + > + netdev->stats.tx_bytes += skb->len; > + > + priv->tx_slot = (priv->tx_slot + 1) % priv->num_tx_slots; > + dev_kfree_skb_any(skb); > + return NETDEV_TX_OK; > +drop: > + /* Drop the packet */ > + dev_kfree_skb_any(skb); > + netdev->stats.tx_dropped++; > + > + 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_reset_hw(struct liteeth *priv) > +{ > + /* Reset, twice */ > + writeb(0, priv->base + LITEETH_PHY_CRG_RESET); > + udelay(10); > + writeb(1, priv->base + LITEETH_PHY_CRG_RESET); > + udelay(10); > + writeb(0, priv->base + LITEETH_PHY_CRG_RESET); > + udelay(10); > +} > + > +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 = alloc_etherdev(sizeof(*priv)); > + if (!netdev) > + return -ENOMEM; > + > + 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\n"); > + goto err; > + } > + > + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); > + priv->base = devm_ioremap_resource(&pdev->dev, res); > + if (IS_ERR(priv->base)) { > + err = PTR_ERR(priv->base); > + goto err; > + } > + > + res = platform_get_resource(pdev, IORESOURCE_MEM, 1); > + priv->mdio_base = devm_ioremap_resource(&pdev->dev, res); > + if (IS_ERR(priv->mdio_base)) { > + err = PTR_ERR(priv->mdio_base); > + goto err; > + } > + > + res = platform_get_resource(pdev, IORESOURCE_MEM, 2); > + buf_base = devm_ioremap_resource(&pdev->dev, res); > + if (IS_ERR(buf_base)) { > + err = PTR_ERR(buf_base); > + goto err; > + } > + > + err = of_property_read_u32(pdev->dev.of_node, "rx-fifo-depth", > + &priv->num_rx_slots); > + if (err) { > + dev_err(&pdev->dev, "unable to get rx-fifo-depth\n"); > + goto err; > + } > + > + err = of_property_read_u32(pdev->dev.of_node, "tx-fifo-depth", > + &priv->num_tx_slots); > + if (err) { > + dev_err(&pdev->dev, "unable to get tx-fifo-depth\n"); > + goto err; > + } > + > + /* 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 * LITEETH_BUFFER_SIZE; > + priv->tx_slot = 0; > + > + err = of_get_mac_address(pdev->dev.of_node, netdev->dev_addr); > + if (err) > + eth_hw_addr_random(netdev); > + > + SET_NETDEV_DEV(netdev, &pdev->dev); > + platform_set_drvdata(pdev, netdev); > + > + netdev->netdev_ops = &liteeth_netdev_ops; > + netdev->irq = irq; > + > + liteeth_reset_hw(priv); > + > + err = register_netdev(netdev); > + if (err) { > + dev_err(&pdev->dev, "Failed to register netdev\n"); > + goto err; > + } > + > + netdev_info(netdev, "irq %d, mapped at %px\n", netdev->irq, priv->base); > + > + return 0; > +err: > + free_netdev(netdev); > + return err; > +} > + > +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@xxxxxxxxx>"); > +MODULE_LICENSE("GPL"); > -- > 2.32.0 >
