diff options
Diffstat (limited to 'drivers/net/mdio/mdio-aspeed.c')
| -rw-r--r-- | drivers/net/mdio/mdio-aspeed.c | 233 |
1 files changed, 233 insertions, 0 deletions
diff --git a/drivers/net/mdio/mdio-aspeed.c b/drivers/net/mdio/mdio-aspeed.c new file mode 100644 index 000000000..944d005d2 --- /dev/null +++ b/drivers/net/mdio/mdio-aspeed.c @@ -0,0 +1,233 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* Copyright (C) 2019 IBM Corp. */ + +#include <linux/bitfield.h> +#include <linux/delay.h> +#include <linux/reset.h> +#include <linux/iopoll.h> +#include <linux/mdio.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/of_mdio.h> +#include <linux/phy.h> +#include <linux/platform_device.h> + +#define DRV_NAME "mdio-aspeed" + +#define ASPEED_MDIO_CTRL 0x0 +#define ASPEED_MDIO_CTRL_FIRE BIT(31) +#define ASPEED_MDIO_CTRL_ST BIT(28) +#define ASPEED_MDIO_CTRL_ST_C45 0 +#define ASPEED_MDIO_CTRL_ST_C22 1 +#define ASPEED_MDIO_CTRL_OP GENMASK(27, 26) +#define MDIO_C22_OP_WRITE 0b01 +#define MDIO_C22_OP_READ 0b10 +#define MDIO_C45_OP_ADDR 0b00 +#define MDIO_C45_OP_WRITE 0b01 +#define MDIO_C45_OP_PREAD 0b10 +#define MDIO_C45_OP_READ 0b11 +#define ASPEED_MDIO_CTRL_PHYAD GENMASK(25, 21) +#define ASPEED_MDIO_CTRL_REGAD GENMASK(20, 16) +#define ASPEED_MDIO_CTRL_MIIWDATA GENMASK(15, 0) + +#define ASPEED_MDIO_DATA 0x4 +#define ASPEED_MDIO_DATA_MDC_THRES GENMASK(31, 24) +#define ASPEED_MDIO_DATA_MDIO_EDGE BIT(23) +#define ASPEED_MDIO_DATA_MDIO_LATCH GENMASK(22, 20) +#define ASPEED_MDIO_DATA_IDLE BIT(16) +#define ASPEED_MDIO_DATA_MIIRDATA GENMASK(15, 0) + +#define ASPEED_MDIO_INTERVAL_US 100 +#define ASPEED_MDIO_TIMEOUT_US (ASPEED_MDIO_INTERVAL_US * 10) + +struct aspeed_mdio { + void __iomem *base; + struct reset_control *reset; +}; + +static int aspeed_mdio_op(struct mii_bus *bus, u8 st, u8 op, u8 phyad, u8 regad, + u16 data) +{ + struct aspeed_mdio *ctx = bus->priv; + u32 ctrl; + + dev_dbg(&bus->dev, "%s: st: %u op: %u, phyad: %u, regad: %u, data: %u\n", + __func__, st, op, phyad, regad, data); + + ctrl = ASPEED_MDIO_CTRL_FIRE + | FIELD_PREP(ASPEED_MDIO_CTRL_ST, st) + | FIELD_PREP(ASPEED_MDIO_CTRL_OP, op) + | FIELD_PREP(ASPEED_MDIO_CTRL_PHYAD, phyad) + | FIELD_PREP(ASPEED_MDIO_CTRL_REGAD, regad) + | FIELD_PREP(ASPEED_MDIO_DATA_MIIRDATA, data); + + iowrite32(ctrl, ctx->base + ASPEED_MDIO_CTRL); + + return readl_poll_timeout(ctx->base + ASPEED_MDIO_CTRL, ctrl, + !(ctrl & ASPEED_MDIO_CTRL_FIRE), + ASPEED_MDIO_INTERVAL_US, + ASPEED_MDIO_TIMEOUT_US); +} + +static int aspeed_mdio_get_data(struct mii_bus *bus) +{ + struct aspeed_mdio *ctx = bus->priv; + u32 data; + int rc; + + rc = readl_poll_timeout(ctx->base + ASPEED_MDIO_DATA, data, + data & ASPEED_MDIO_DATA_IDLE, + ASPEED_MDIO_INTERVAL_US, + ASPEED_MDIO_TIMEOUT_US); + if (rc < 0) + return rc; + + return FIELD_GET(ASPEED_MDIO_DATA_MIIRDATA, data); +} + +static int aspeed_mdio_read_c22(struct mii_bus *bus, int addr, int regnum) +{ + int rc; + + rc = aspeed_mdio_op(bus, ASPEED_MDIO_CTRL_ST_C22, MDIO_C22_OP_READ, + addr, regnum, 0); + if (rc < 0) + return rc; + + return aspeed_mdio_get_data(bus); +} + +static int aspeed_mdio_write_c22(struct mii_bus *bus, int addr, int regnum, + u16 val) +{ + return aspeed_mdio_op(bus, ASPEED_MDIO_CTRL_ST_C22, MDIO_C22_OP_WRITE, + addr, regnum, val); +} + +static int aspeed_mdio_read_c45(struct mii_bus *bus, int addr, int regnum) +{ + u8 c45_dev = (regnum >> 16) & 0x1F; + u16 c45_addr = regnum & 0xFFFF; + int rc; + + rc = aspeed_mdio_op(bus, ASPEED_MDIO_CTRL_ST_C45, MDIO_C45_OP_ADDR, + addr, c45_dev, c45_addr); + if (rc < 0) + return rc; + + rc = aspeed_mdio_op(bus, ASPEED_MDIO_CTRL_ST_C45, MDIO_C45_OP_READ, + addr, c45_dev, 0); + if (rc < 0) + return rc; + + return aspeed_mdio_get_data(bus); +} + +static int aspeed_mdio_write_c45(struct mii_bus *bus, int addr, int regnum, + u16 val) +{ + u8 c45_dev = (regnum >> 16) & 0x1F; + u16 c45_addr = regnum & 0xFFFF; + int rc; + + rc = aspeed_mdio_op(bus, ASPEED_MDIO_CTRL_ST_C45, MDIO_C45_OP_ADDR, + addr, c45_dev, c45_addr); + if (rc < 0) + return rc; + + return aspeed_mdio_op(bus, ASPEED_MDIO_CTRL_ST_C45, MDIO_C45_OP_WRITE, + addr, c45_dev, val); +} + +static int aspeed_mdio_read(struct mii_bus *bus, int addr, int regnum) +{ + dev_dbg(&bus->dev, "%s: addr: %d, regnum: %d\n", __func__, addr, + regnum); + + if (regnum & MII_ADDR_C45) + return aspeed_mdio_read_c45(bus, addr, regnum); + + return aspeed_mdio_read_c22(bus, addr, regnum); +} + +static int aspeed_mdio_write(struct mii_bus *bus, int addr, int regnum, u16 val) +{ + dev_dbg(&bus->dev, "%s: addr: %d, regnum: %d, val: 0x%x\n", + __func__, addr, regnum, val); + + if (regnum & MII_ADDR_C45) + return aspeed_mdio_write_c45(bus, addr, regnum, val); + + return aspeed_mdio_write_c22(bus, addr, regnum, val); +} + +static int aspeed_mdio_probe(struct platform_device *pdev) +{ + struct aspeed_mdio *ctx; + struct mii_bus *bus; + int rc; + + bus = devm_mdiobus_alloc_size(&pdev->dev, sizeof(*ctx)); + if (!bus) + return -ENOMEM; + + ctx = bus->priv; + ctx->base = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(ctx->base)) + return PTR_ERR(ctx->base); + + ctx->reset = devm_reset_control_get_optional_shared(&pdev->dev, NULL); + if (IS_ERR(ctx->reset)) + return PTR_ERR(ctx->reset); + + reset_control_deassert(ctx->reset); + + bus->name = DRV_NAME; + snprintf(bus->id, MII_BUS_ID_SIZE, "%s%d", pdev->name, pdev->id); + bus->parent = &pdev->dev; + bus->read = aspeed_mdio_read; + bus->write = aspeed_mdio_write; + bus->probe_capabilities = MDIOBUS_C22_C45; + + rc = of_mdiobus_register(bus, pdev->dev.of_node); + if (rc) { + dev_err(&pdev->dev, "Cannot register MDIO bus!\n"); + reset_control_assert(ctx->reset); + return rc; + } + + platform_set_drvdata(pdev, bus); + + return 0; +} + +static int aspeed_mdio_remove(struct platform_device *pdev) +{ + struct mii_bus *bus = (struct mii_bus *)platform_get_drvdata(pdev); + struct aspeed_mdio *ctx = bus->priv; + + reset_control_assert(ctx->reset); + mdiobus_unregister(bus); + + return 0; +} + +static const struct of_device_id aspeed_mdio_of_match[] = { + { .compatible = "aspeed,ast2600-mdio", }, + { }, +}; +MODULE_DEVICE_TABLE(of, aspeed_mdio_of_match); + +static struct platform_driver aspeed_mdio_driver = { + .driver = { + .name = DRV_NAME, + .of_match_table = aspeed_mdio_of_match, + }, + .probe = aspeed_mdio_probe, + .remove = aspeed_mdio_remove, +}; + +module_platform_driver(aspeed_mdio_driver); + +MODULE_AUTHOR("Andrew Jeffery <andrew@aj.id.au>"); +MODULE_LICENSE("GPL"); |