1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Allwinner EMAC MDIO interface driver 4 * 5 * Copyright 2012-2013 Stefan Roese <sr@denx.de> 6 * Copyright 2013 Maxime Ripard <maxime.ripard@free-electrons.com> 7 * 8 * Based on the Linux driver provided by Allwinner: 9 * Copyright (C) 1997 Sten Wang 10 */ 11 12 #include <linux/delay.h> 13 #include <linux/kernel.h> 14 #include <linux/module.h> 15 #include <linux/mutex.h> 16 #include <linux/of_address.h> 17 #include <linux/of_mdio.h> 18 #include <linux/phy.h> 19 #include <linux/platform_device.h> 20 #include <linux/regulator/consumer.h> 21 22 #define EMAC_MAC_MCMD_REG (0x00) 23 #define EMAC_MAC_MADR_REG (0x04) 24 #define EMAC_MAC_MWTD_REG (0x08) 25 #define EMAC_MAC_MRDD_REG (0x0c) 26 #define EMAC_MAC_MIND_REG (0x10) 27 #define EMAC_MAC_SSRR_REG (0x14) 28 29 #define MDIO_TIMEOUT (msecs_to_jiffies(100)) 30 31 struct sun4i_mdio_data { 32 void __iomem *membase; 33 struct regulator *regulator; 34 }; 35 36 static int sun4i_mdio_read(struct mii_bus *bus, int mii_id, int regnum) 37 { 38 struct sun4i_mdio_data *data = bus->priv; 39 unsigned long timeout_jiffies; 40 int value; 41 42 /* issue the phy address and reg */ 43 writel((mii_id << 8) | regnum, data->membase + EMAC_MAC_MADR_REG); 44 /* pull up the phy io line */ 45 writel(0x1, data->membase + EMAC_MAC_MCMD_REG); 46 47 /* Wait read complete */ 48 timeout_jiffies = jiffies + MDIO_TIMEOUT; 49 while (readl(data->membase + EMAC_MAC_MIND_REG) & 0x1) { 50 if (time_is_before_jiffies(timeout_jiffies)) 51 return -ETIMEDOUT; 52 msleep(1); 53 } 54 55 /* push down the phy io line */ 56 writel(0x0, data->membase + EMAC_MAC_MCMD_REG); 57 /* and read data */ 58 value = readl(data->membase + EMAC_MAC_MRDD_REG); 59 60 return value; 61 } 62 63 static int sun4i_mdio_write(struct mii_bus *bus, int mii_id, int regnum, 64 u16 value) 65 { 66 struct sun4i_mdio_data *data = bus->priv; 67 unsigned long timeout_jiffies; 68 69 /* issue the phy address and reg */ 70 writel((mii_id << 8) | regnum, data->membase + EMAC_MAC_MADR_REG); 71 /* pull up the phy io line */ 72 writel(0x1, data->membase + EMAC_MAC_MCMD_REG); 73 74 /* Wait read complete */ 75 timeout_jiffies = jiffies + MDIO_TIMEOUT; 76 while (readl(data->membase + EMAC_MAC_MIND_REG) & 0x1) { 77 if (time_is_before_jiffies(timeout_jiffies)) 78 return -ETIMEDOUT; 79 msleep(1); 80 } 81 82 /* push down the phy io line */ 83 writel(0x0, data->membase + EMAC_MAC_MCMD_REG); 84 /* and write data */ 85 writel(value, data->membase + EMAC_MAC_MWTD_REG); 86 87 return 0; 88 } 89 90 static int sun4i_mdio_probe(struct platform_device *pdev) 91 { 92 struct device_node *np = pdev->dev.of_node; 93 struct mii_bus *bus; 94 struct sun4i_mdio_data *data; 95 int ret; 96 97 bus = mdiobus_alloc_size(sizeof(*data)); 98 if (!bus) 99 return -ENOMEM; 100 101 bus->name = "sun4i_mii_bus"; 102 bus->read = &sun4i_mdio_read; 103 bus->write = &sun4i_mdio_write; 104 snprintf(bus->id, MII_BUS_ID_SIZE, "%s-mii", dev_name(&pdev->dev)); 105 bus->parent = &pdev->dev; 106 107 data = bus->priv; 108 data->membase = devm_platform_ioremap_resource(pdev, 0); 109 if (IS_ERR(data->membase)) { 110 ret = PTR_ERR(data->membase); 111 goto err_out_free_mdiobus; 112 } 113 114 data->regulator = devm_regulator_get(&pdev->dev, "phy"); 115 if (IS_ERR(data->regulator)) { 116 if (PTR_ERR(data->regulator) == -EPROBE_DEFER) { 117 ret = -EPROBE_DEFER; 118 goto err_out_free_mdiobus; 119 } 120 121 dev_info(&pdev->dev, "no regulator found\n"); 122 data->regulator = NULL; 123 } else { 124 ret = regulator_enable(data->regulator); 125 if (ret) 126 goto err_out_free_mdiobus; 127 } 128 129 ret = of_mdiobus_register(bus, np); 130 if (ret < 0) 131 goto err_out_disable_regulator; 132 133 platform_set_drvdata(pdev, bus); 134 135 return 0; 136 137 err_out_disable_regulator: 138 if (data->regulator) 139 regulator_disable(data->regulator); 140 err_out_free_mdiobus: 141 mdiobus_free(bus); 142 return ret; 143 } 144 145 static void sun4i_mdio_remove(struct platform_device *pdev) 146 { 147 struct mii_bus *bus = platform_get_drvdata(pdev); 148 struct sun4i_mdio_data *data = bus->priv; 149 150 mdiobus_unregister(bus); 151 if (data->regulator) 152 regulator_disable(data->regulator); 153 mdiobus_free(bus); 154 } 155 156 static const struct of_device_id sun4i_mdio_dt_ids[] = { 157 { .compatible = "allwinner,sun4i-a10-mdio" }, 158 159 /* Deprecated */ 160 { .compatible = "allwinner,sun4i-mdio" }, 161 { } 162 }; 163 MODULE_DEVICE_TABLE(of, sun4i_mdio_dt_ids); 164 165 static struct platform_driver sun4i_mdio_driver = { 166 .probe = sun4i_mdio_probe, 167 .remove_new = sun4i_mdio_remove, 168 .driver = { 169 .name = "sun4i-mdio", 170 .of_match_table = sun4i_mdio_dt_ids, 171 }, 172 }; 173 174 module_platform_driver(sun4i_mdio_driver); 175 176 MODULE_DESCRIPTION("Allwinner EMAC MDIO interface driver"); 177 MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>"); 178 MODULE_LICENSE("GPL v2"); 179