| // SPDX-License-Identifier: GPL-2.0 |
| /* |
| * 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 |
| */ |
| |
| #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; |
| 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; |
| data->membase = devm_platform_ioremap_resource(pdev, 0); |
| 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) { |
| ret = -EPROBE_DEFER; |
| goto err_out_free_mdiobus; |
| } |
| |
| dev_info(&pdev->dev, "no regulator found\n"); |
| data->regulator = NULL; |
| } 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: |
| if (data->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 v2"); |