LiteX is a soft system-on-chip that targets FPGAs. LiteETH is a basic network device that is commonly used in LiteX designs.
Signed-off-by: Joel Stanley joel@jms.id.au --- include/linux/litex.h | 83 ++++++++++++++++ drivers/net/liteeth.c | 214 ++++++++++++++++++++++++++++++++++++++++++ drivers/net/Kconfig | 5 + drivers/net/Makefile | 1 + 4 files changed, 303 insertions(+) create mode 100644 include/linux/litex.h create mode 100644 drivers/net/liteeth.c
diff --git a/include/linux/litex.h b/include/linux/litex.h new file mode 100644 index 000000000000..f2edb86d5f44 --- /dev/null +++ b/include/linux/litex.h @@ -0,0 +1,83 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Common LiteX header providing + * helper functions for accessing CSRs. + * + * Copyright (C) 2019-2020 Antmicro <www.antmicro.com> + */ + +#ifndef _LINUX_LITEX_H +#define _LINUX_LITEX_H + +#include <linux/io.h> + +static inline void _write_litex_subregister(u32 val, void __iomem *addr) +{ + writel((u32 __force)cpu_to_le32(val), addr); +} + +static inline u32 _read_litex_subregister(void __iomem *addr) +{ + return le32_to_cpu((__le32 __force)readl(addr)); +} + +/* + * LiteX SoC Generator, depending on the configuration, can split a single + * logical CSR (Control&Status Register) into a series of consecutive physical + * registers. + * + * For example, in the configuration with 8-bit CSR Bus, a 32-bit aligned, + * 32-bit wide logical CSR will be laid out as four 32-bit physical + * subregisters, each one containing one byte of meaningful data. + * + * For Linux support, upstream LiteX enforces a 32-bit wide CSR bus, which + * means that only larger-than-32-bit CSRs will be split across multiple + * subregisters (e.g., a 64-bit CSR will be spread across two consecutive + * 32-bit subregisters). + * + * For details see: https://github.com/enjoy-digital/litex/wiki/CSR-Bus + */ + +static inline void litex_write8(void __iomem *reg, u8 val) +{ + _write_litex_subregister(val, reg); +} + +static inline void litex_write16(void __iomem *reg, u16 val) +{ + _write_litex_subregister(val, reg); +} + +static inline void litex_write32(void __iomem *reg, u32 val) +{ + _write_litex_subregister(val, reg); +} + +static inline void litex_write64(void __iomem *reg, u64 val) +{ + _write_litex_subregister(val >> 32, reg); + _write_litex_subregister(val, reg + 4); +} + +static inline u8 litex_read8(void __iomem *reg) +{ + return _read_litex_subregister(reg); +} + +static inline u16 litex_read16(void __iomem *reg) +{ + return _read_litex_subregister(reg); +} + +static inline u32 litex_read32(void __iomem *reg) +{ + return _read_litex_subregister(reg); +} + +static inline u64 litex_read64(void __iomem *reg) +{ + return ((u64)_read_litex_subregister(reg) << 32) | + _read_litex_subregister(reg + 4); +} + +#endif /* _LINUX_LITEX_H */ diff --git a/drivers/net/liteeth.c b/drivers/net/liteeth.c new file mode 100644 index 000000000000..5da713a9c7a1 --- /dev/null +++ b/drivers/net/liteeth.c @@ -0,0 +1,214 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * LiteX Liteeth Ethernet + * + * Copyright 2021 Joel Stanley joel@jms.id.au, IBM Corp. + */ + +#include <linux/litex.h> + +#include <dm.h> +#include <dm/device_compat.h> +#include <net.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 + +struct liteeth { + struct udevice *dev; + + void __iomem *base; + 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_recv(struct udevice *dev, int flags, uchar **packetp) +{ + struct liteeth *priv = dev_get_priv(dev); + u8 rx_slot; + int len; + + if (!litex_read8(priv->base + LITEETH_WRITER_EV_PENDING)) { + debug("liteeth: No packet ready\n"); + return -EPERM; + } + + rx_slot = litex_read8(priv->base + LITEETH_WRITER_SLOT); + len = litex_read32(priv->base + LITEETH_WRITER_LENGTH); + + debug("%s: slot %d len 0x%x\n", __func__, rx_slot, len); + + *packetp = priv->rx_base + rx_slot * priv->slot_size; + + return len; +} + +static int liteeth_free_pkt(struct udevice *dev, uchar *packet, int length) +{ + struct liteeth *priv = dev_get_priv(dev); + + litex_write8(priv->base + LITEETH_WRITER_EV_PENDING, 1); + + return 0; +} + +static int liteeth_start(struct udevice *dev) +{ + struct liteeth *priv = dev_get_priv(dev); + + /* Clear pending events */ + litex_write8(priv->base + LITEETH_WRITER_EV_PENDING, 1); + litex_write8(priv->base + LITEETH_READER_EV_PENDING, 1); + + /* Enable events */ + litex_write8(priv->base + LITEETH_WRITER_EV_ENABLE, 1); + litex_write8(priv->base + LITEETH_READER_EV_ENABLE, 1); + + return 0; +} + +static void liteeth_stop(struct udevice *dev) +{ + struct liteeth *priv = dev_get_priv(dev); + + litex_write8(priv->base + LITEETH_WRITER_EV_ENABLE, 0); + litex_write8(priv->base + LITEETH_READER_EV_ENABLE, 0); +} + +static int liteeth_send(struct udevice *dev, void *packet, int len) +{ + struct liteeth *priv = dev_get_priv(dev); + void __iomem *txbuffer; + + if (!litex_read8(priv->base + LITEETH_READER_READY)) { + printf("liteeth: reader not ready\n"); + return -EPERM; + } + + /* Reject oversize packets */ + if (unlikely(len > priv->slot_size)) + return -EPERM; + + txbuffer = priv->tx_base + priv->tx_slot * priv->slot_size; + memcpy_toio(txbuffer, packet, len); + litex_write8(priv->base + LITEETH_READER_SLOT, priv->tx_slot); + litex_write16(priv->base + LITEETH_READER_LENGTH, len); + litex_write8(priv->base + LITEETH_READER_START, 1); + + priv->tx_slot = (priv->tx_slot + 1) % priv->num_tx_slots; + + return 0; +} + +static void liteeth_setup_slots(struct liteeth *priv) +{ + int err; + + err = ofnode_read_u32(dev_ofnode(priv->dev), "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 = ofnode_read_u32(dev_ofnode(priv->dev), "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 = ofnode_read_u32(dev_ofnode(priv->dev), "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_remove(struct udevice *dev) +{ + liteeth_stop(dev); + + return 0; +} + +static const struct eth_ops liteeth_ops = { + .start = liteeth_start, + .stop = liteeth_stop, + .send = liteeth_send, + .recv = liteeth_recv, + .free_pkt = liteeth_free_pkt, +}; + +static int liteeth_of_to_plat(struct udevice *dev) +{ + struct eth_pdata *pdata = dev_get_plat(dev); + struct liteeth *priv = dev_get_priv(dev); + void __iomem *buf_base; + + pdata->iobase = dev_read_addr(dev); + + priv->dev = dev; + + priv->base = dev_remap_addr_name(dev, "mac"); + if (!priv->base) { + dev_err(dev, "failed to map registers\n"); + return -EINVAL; + } + + buf_base = dev_remap_addr_name(dev, "buffer"); + if (!buf_base) { + dev_err(dev, "failed to map buffer\n"); + return -EINVAL; + } + + 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; + + return 0; +} + +static const struct udevice_id liteeth_ids[] = { + { .compatible = "litex,liteeth" }, + {} +}; + +U_BOOT_DRIVER(liteeth) = { + .name = "liteeth", + .id = UCLASS_ETH, + .of_match = liteeth_ids, + .of_to_plat = liteeth_of_to_plat, + .plat_auto = sizeof(struct eth_pdata), + .remove = liteeth_remove, + .ops = &liteeth_ops, + .priv_auto = sizeof(struct liteeth), +}; diff --git a/drivers/net/Kconfig b/drivers/net/Kconfig index 52dc9e4f0f6d..95420bd4a140 100644 --- a/drivers/net/Kconfig +++ b/drivers/net/Kconfig @@ -460,6 +460,11 @@ config LPC32XX_ETH depends on ARCH_LPC32XX default y
+config LITEETH + bool "LiteX LiteEth Ethernet MAC" + help + Driver for the LiteEth Ethernet MAC from LiteX. + config MVGBE bool "Marvell Orion5x/Kirkwood network interface support" depends on ARCH_KIRKWOOD || ARCH_ORION5X diff --git a/drivers/net/Makefile b/drivers/net/Makefile index 054ec68470db..770107296c62 100644 --- a/drivers/net/Makefile +++ b/drivers/net/Makefile @@ -47,6 +47,7 @@ obj-$(CONFIG_GMAC_ROCKCHIP) += gmac_rockchip.o obj-$(CONFIG_HIGMACV300_ETH) += higmacv300.o obj-$(CONFIG_KS8851_MLL) += ks8851_mll.o obj-$(CONFIG_KSZ9477) += ksz9477.o +obj-$(CONFIG_LITEETH) += liteeth.o obj-$(CONFIG_LPC32XX_ETH) += lpc32xx_eth.o obj-$(CONFIG_MACB) += macb.o obj-$(CONFIG_MCFFEC) += mcffec.o mcfmii.o