mdio-sun4i.c
/*
* Allwinner EMAC MDIO interface driver
*
* Copyright 2012-2013 Stefan Roese <sr@denx.de>
* Copyright 2013 Maxime Ripard <maxime.ripard@free-electrons.com>
*
* Based on the Linux driver provided by Allwinner:
* Copyright (C) 1997 Sten Wang
*
* This file is licensed under the terms of the GNU General Public
* License version 2. This program is licensed "as is" without any
* warranty of any kind, whether express or implied.
*/
#include <linux/delay.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/of_address.h>
#include <linux/of_mdio.h>
#include <linux/phy.h>
#include <linux/platform_device.h>
#include <linux/regulator/consumer.h>
#define EMAC_MAC_MCMD_REG (0x00)
#define EMAC_MAC_MADR_REG (0x04)
#define EMAC_MAC_MWTD_REG (0x08)
#define EMAC_MAC_MRDD_REG (0x0c)
#define EMAC_MAC_MIND_REG (0x10)
#define EMAC_MAC_SSRR_REG (0x14)
#define MDIO_TIMEOUT (msecs_to_jiffies(100))
struct sun4i_mdio_data {
void __iomem *membase;
struct regulator *regulator;
};
static int sun4i_mdio_read(struct mii_bus *bus, int mii_id, int regnum)
{
struct sun4i_mdio_data *data = bus->priv;
unsigned long timeout_jiffies;
int value;
/* issue the phy address and reg */
writel((mii_id << 8) | regnum, data->membase + EMAC_MAC_MADR_REG);
/* pull up the phy io line */
writel(0x1, data->membase + EMAC_MAC_MCMD_REG);
/* Wait read complete */
timeout_jiffies = jiffies + MDIO_TIMEOUT;
while (readl(data->membase + EMAC_MAC_MIND_REG) & 0x1) {
if (time_is_before_jiffies(timeout_jiffies))
return -ETIMEDOUT;
msleep(1);
}
/* push down the phy io line */
writel(0x0, data->membase + EMAC_MAC_MCMD_REG);
/* and read data */
value = readl(data->membase + EMAC_MAC_MRDD_REG);
return value;
}
static int sun4i_mdio_write(struct mii_bus *bus, int mii_id, int regnum,
u16 value)
{
struct sun4i_mdio_data *data = bus->priv;
unsigned long timeout_jiffies;
/* issue the phy address and reg */
writel((mii_id << 8) | regnum, data->membase + EMAC_MAC_MADR_REG);
/* pull up the phy io line */
writel(0x1, data->membase + EMAC_MAC_MCMD_REG);
/* Wait read complete */
timeout_jiffies = jiffies + MDIO_TIMEOUT;
while (readl(data->membase + EMAC_MAC_MIND_REG) & 0x1) {
if (time_is_before_jiffies(timeout_jiffies))
return -ETIMEDOUT;
msleep(1);
}
/* push down the phy io line */
writel(0x0, data->membase + EMAC_MAC_MCMD_REG);
/* and write data */
writel(value, data->membase + EMAC_MAC_MWTD_REG);
return 0;
}
static int sun4i_mdio_probe(struct platform_device *pdev)
{
struct device_node *np = pdev->dev.of_node;
struct mii_bus *bus;
struct sun4i_mdio_data *data;
struct resource *res;
int ret;
bus = mdiobus_alloc_size(sizeof(*data));
if (!bus)
return -ENOMEM;
bus->name = "sun4i_mii_bus";
bus->read = &sun4i_mdio_read;
bus->write = &sun4i_mdio_write;
snprintf(bus->id, MII_BUS_ID_SIZE, "%s-mii", dev_name(&pdev->dev));
bus->parent = &pdev->dev;
data = bus->priv;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
data->membase = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(data->membase)) {
ret = PTR_ERR(data->membase);
goto err_out_free_mdiobus;
}
data->regulator = devm_regulator_get(&pdev->dev, "phy");
if (IS_ERR(data->regulator)) {
if (PTR_ERR(data->regulator) == -EPROBE_DEFER)
return -EPROBE_DEFER;
dev_info(&pdev->dev, "no regulator found\n");
} else {
ret = regulator_enable(data->regulator);
if (ret)
goto err_out_free_mdiobus;
}
ret = of_mdiobus_register(bus, np);
if (ret < 0)
goto err_out_disable_regulator;
platform_set_drvdata(pdev, bus);
return 0;
err_out_disable_regulator:
regulator_disable(data->regulator);
err_out_free_mdiobus:
mdiobus_free(bus);
return ret;
}
static int sun4i_mdio_remove(struct platform_device *pdev)
{
struct mii_bus *bus = platform_get_drvdata(pdev);
mdiobus_unregister(bus);
mdiobus_free(bus);
return 0;
}
static const struct of_device_id sun4i_mdio_dt_ids[] = {
{ .compatible = "allwinner,sun4i-a10-mdio" },
/* Deprecated */
{ .compatible = "allwinner,sun4i-mdio" },
{ }
};
MODULE_DEVICE_TABLE(of, sun4i_mdio_dt_ids);
static struct platform_driver sun4i_mdio_driver = {
.probe = sun4i_mdio_probe,
.remove = sun4i_mdio_remove,
.driver = {
.name = "sun4i-mdio",
.of_match_table = sun4i_mdio_dt_ids,
},
};
module_platform_driver(sun4i_mdio_driver);
MODULE_DESCRIPTION("Allwinner EMAC MDIO interface driver");
MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
MODULE_LICENSE("GPL");