blob: c2170650415cdbd9d6076fe12e0014c33e40be15 [file] [log] [blame]
// 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 devad,
int regnum)
{
int rc;
rc = aspeed_mdio_op(bus, ASPEED_MDIO_CTRL_ST_C45, MDIO_C45_OP_ADDR,
addr, devad, regnum);
if (rc < 0)
return rc;
rc = aspeed_mdio_op(bus, ASPEED_MDIO_CTRL_ST_C45, MDIO_C45_OP_READ,
addr, devad, 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 devad,
int regnum, u16 val)
{
int rc;
rc = aspeed_mdio_op(bus, ASPEED_MDIO_CTRL_ST_C45, MDIO_C45_OP_ADDR,
addr, devad, regnum);
if (rc < 0)
return rc;
return aspeed_mdio_op(bus, ASPEED_MDIO_CTRL_ST_C45, MDIO_C45_OP_WRITE,
addr, devad, 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_c22;
bus->write = aspeed_mdio_write_c22;
bus->read_c45 = aspeed_mdio_read_c45;
bus->write_c45 = aspeed_mdio_write_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 void 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);
}
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_new = aspeed_mdio_remove,
};
module_platform_driver(aspeed_mdio_driver);
MODULE_AUTHOR("Andrew Jeffery <andrew@aj.id.au>");
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("ASPEED MDIO bus controller");