/*
* Hisilicon Fast Ethernet MDIO Bus Driver
*
* Copyright (c) 2016 HiSilicon Technologies Co., Ltd.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <linux/clk.h>
#include <linux/iopoll.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of_address.h>
#include <linux/of_mdio.h>
#include <linux/platform_device.h>
#define MDIO_RWCTRL 0x00
#define MDIO_RO_DATA 0x04
#define MDIO_WRITE BIT(13)
#define MDIO_RW_FINISH BIT(15)
#define BIT_PHY_ADDR_OFFSET 8
#define BIT_WR_DATA_OFFSET 16
struct hisi_femac_mdio_data {
struct clk *clk;
void __iomem *membase;
};
static int hisi_femac_mdio_wait_ready(struct hisi_femac_mdio_data *data)
{
u32 val;
return readl_poll_timeout(data->membase + MDIO_RWCTRL,
val, val & MDIO_RW_FINISH, 20, 10000);
}
static int hisi_femac_mdio_read(struct mii_bus *bus, int mii_id, int regnum)
{
struct hisi_femac_mdio_data *data = bus->priv;
int ret;
ret = hisi_femac_mdio_wait_ready(data);
if (ret)
return ret;
writel((mii_id << BIT_PHY_ADDR_OFFSET) | regnum,
data->membase + MDIO_RWCTRL);
ret = hisi_femac_mdio_wait_ready(data);
if (ret)
return ret;
return readl(data->membase + MDIO_RO_DATA) & 0xFFFF;
}
static int hisi_femac_mdio_write(struct mii_bus *bus, int mii_id, int regnum,
u16 value)
{
struct hisi_femac_mdio_data *data = bus->priv;
int ret;
ret = hisi_femac_mdio_wait_ready(data);
if (ret)
return ret;
writel(MDIO_WRITE | (value << BIT_WR_DATA_OFFSET) |
(mii_id << BIT_PHY_ADDR_OFFSET) | regnum,
data->membase + MDIO_RWCTRL);
return hisi_femac_mdio_wait_ready(data);
}
static int hisi_femac_mdio_probe(struct platform_device *pdev)
{
struct device_node *np = pdev->dev.of_node;
struct mii_bus *bus;
struct hisi_femac_mdio_data *data;
struct resource *res;
int ret;
bus = mdiobus_alloc_size(sizeof(*data));
if (!bus)
return -ENOMEM;
bus->name = "hisi_femac_mii_bus";
bus->read = &hisi_femac_mdio_read;
bus->write = &hisi_femac_mdio_write;
snprintf(bus->id, MII_BUS_ID_SIZE, "%s", pdev->name);
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->clk = devm_clk_get(&pdev->dev, NULL);
if (IS_ERR(data->clk)) {
ret = PTR_ERR(data->clk);
goto err_out_free_mdiobus;
}
ret = clk_prepare_enable(data->clk);
if (ret)
goto err_out_free_mdiobus;
ret = of_mdiobus_register(bus, np);
if (ret)
goto err_out_disable_clk;
platform_set_drvdata(pdev, bus);
return 0;
err_out_disable_clk:
clk_disable_unprepare(data->clk);
err_out_free_mdiobus:
mdiobus_free(bus);
return ret;
}
static int hisi_femac_mdio_remove(struct platform_device *pdev)
{
struct mii_bus *bus = platform_get_drvdata(pdev);
struct hisi_femac_mdio_data *data = bus->priv;
mdiobus_unregister(bus);
clk_disable_unprepare(data->clk);
mdiobus_free(bus);
return 0;
}
static const struct of_device_id hisi_femac_mdio_dt_ids[] = {
{ .compatible = "hisilicon,hisi-femac-mdio" },
{ }
};
MODULE_DEVICE_TABLE(of, hisi_femac_mdio_dt_ids);
static struct platform_driver hisi_femac_mdio_driver = {
.probe = hisi_femac_mdio_probe,
.remove = hisi_femac_mdio_remove,
.driver = {
.name = "hisi-femac-mdio",
.of_match_table = hisi_femac_mdio_dt_ids,
},
};
module_platform_driver(hisi_femac_mdio_driver);
MODULE_DESCRIPTION("Hisilicon Fast Ethernet MAC MDIO interface driver");
MODULE_AUTHOR("Dongpo Li <lidongpo@hisilicon.com>");
MODULE_LICENSE("GPL v2");
