1 // SPDX-License-Identifier: GPL-2.0 2 /* Qualcomm IPQ8064 MDIO interface driver 3 * 4 * Copyright (C) 2019 Christian Lamparter <chunkeey@gmail.com> 5 * Copyright (C) 2020 Ansuel Smith <ansuelsmth@gmail.com> 6 */ 7 8 #include <linux/delay.h> 9 #include <linux/kernel.h> 10 #include <linux/mfd/syscon.h> 11 #include <linux/module.h> 12 #include <linux/of_mdio.h> 13 #include <linux/phy.h> 14 #include <linux/platform_device.h> 15 #include <linux/regmap.h> 16 17 /* MII address register definitions */ 18 #define MII_ADDR_REG_ADDR 0x10 19 #define MII_BUSY BIT(0) 20 #define MII_WRITE BIT(1) 21 #define MII_CLKRANGE_60_100M (0 << 2) 22 #define MII_CLKRANGE_100_150M (1 << 2) 23 #define MII_CLKRANGE_20_35M (2 << 2) 24 #define MII_CLKRANGE_35_60M (3 << 2) 25 #define MII_CLKRANGE_150_250M (4 << 2) 26 #define MII_CLKRANGE_250_300M (5 << 2) 27 #define MII_CLKRANGE_MASK GENMASK(4, 2) 28 #define MII_REG_SHIFT 6 29 #define MII_REG_MASK GENMASK(10, 6) 30 #define MII_ADDR_SHIFT 11 31 #define MII_ADDR_MASK GENMASK(15, 11) 32 33 #define MII_DATA_REG_ADDR 0x14 34 35 #define MII_MDIO_DELAY_USEC (1000) 36 #define MII_MDIO_RETRY_MSEC (10) 37 38 struct ipq8064_mdio { 39 struct regmap *base; /* NSS_GMAC0_BASE */ 40 }; 41 42 static int 43 ipq8064_mdio_wait_busy(struct ipq8064_mdio *priv) 44 { 45 u32 busy; 46 47 return regmap_read_poll_timeout(priv->base, MII_ADDR_REG_ADDR, busy, 48 !(busy & MII_BUSY), MII_MDIO_DELAY_USEC, 49 MII_MDIO_RETRY_MSEC * USEC_PER_MSEC); 50 } 51 52 static int 53 ipq8064_mdio_read(struct mii_bus *bus, int phy_addr, int reg_offset) 54 { 55 u32 miiaddr = MII_BUSY | MII_CLKRANGE_250_300M; 56 struct ipq8064_mdio *priv = bus->priv; 57 u32 ret_val; 58 int err; 59 60 /* Reject clause 45 */ 61 if (reg_offset & MII_ADDR_C45) 62 return -EOPNOTSUPP; 63 64 miiaddr |= ((phy_addr << MII_ADDR_SHIFT) & MII_ADDR_MASK) | 65 ((reg_offset << MII_REG_SHIFT) & MII_REG_MASK); 66 67 regmap_write(priv->base, MII_ADDR_REG_ADDR, miiaddr); 68 usleep_range(8, 10); 69 70 err = ipq8064_mdio_wait_busy(priv); 71 if (err) 72 return err; 73 74 regmap_read(priv->base, MII_DATA_REG_ADDR, &ret_val); 75 return (int)ret_val; 76 } 77 78 static int 79 ipq8064_mdio_write(struct mii_bus *bus, int phy_addr, int reg_offset, u16 data) 80 { 81 u32 miiaddr = MII_WRITE | MII_BUSY | MII_CLKRANGE_250_300M; 82 struct ipq8064_mdio *priv = bus->priv; 83 84 /* Reject clause 45 */ 85 if (reg_offset & MII_ADDR_C45) 86 return -EOPNOTSUPP; 87 88 regmap_write(priv->base, MII_DATA_REG_ADDR, data); 89 90 miiaddr |= ((phy_addr << MII_ADDR_SHIFT) & MII_ADDR_MASK) | 91 ((reg_offset << MII_REG_SHIFT) & MII_REG_MASK); 92 93 regmap_write(priv->base, MII_ADDR_REG_ADDR, miiaddr); 94 usleep_range(8, 10); 95 96 return ipq8064_mdio_wait_busy(priv); 97 } 98 99 static int 100 ipq8064_mdio_probe(struct platform_device *pdev) 101 { 102 struct device_node *np = pdev->dev.of_node; 103 struct ipq8064_mdio *priv; 104 struct mii_bus *bus; 105 int ret; 106 107 bus = devm_mdiobus_alloc_size(&pdev->dev, sizeof(*priv)); 108 if (!bus) 109 return -ENOMEM; 110 111 bus->name = "ipq8064_mdio_bus"; 112 bus->read = ipq8064_mdio_read; 113 bus->write = ipq8064_mdio_write; 114 snprintf(bus->id, MII_BUS_ID_SIZE, "%s-mii", dev_name(&pdev->dev)); 115 bus->parent = &pdev->dev; 116 117 priv = bus->priv; 118 priv->base = device_node_to_regmap(np); 119 if (IS_ERR(priv->base)) { 120 if (priv->base == ERR_PTR(-EPROBE_DEFER)) 121 return -EPROBE_DEFER; 122 123 dev_err(&pdev->dev, "error getting device regmap, error=%pe\n", 124 priv->base); 125 return PTR_ERR(priv->base); 126 } 127 128 ret = of_mdiobus_register(bus, np); 129 if (ret) 130 return ret; 131 132 platform_set_drvdata(pdev, bus); 133 return 0; 134 } 135 136 static int 137 ipq8064_mdio_remove(struct platform_device *pdev) 138 { 139 struct mii_bus *bus = platform_get_drvdata(pdev); 140 141 mdiobus_unregister(bus); 142 143 return 0; 144 } 145 146 static const struct of_device_id ipq8064_mdio_dt_ids[] = { 147 { .compatible = "qcom,ipq8064-mdio" }, 148 { } 149 }; 150 MODULE_DEVICE_TABLE(of, ipq8064_mdio_dt_ids); 151 152 static struct platform_driver ipq8064_mdio_driver = { 153 .probe = ipq8064_mdio_probe, 154 .remove = ipq8064_mdio_remove, 155 .driver = { 156 .name = "ipq8064-mdio", 157 .of_match_table = ipq8064_mdio_dt_ids, 158 }, 159 }; 160 161 module_platform_driver(ipq8064_mdio_driver); 162 163 MODULE_DESCRIPTION("Qualcomm IPQ8064 MDIO interface driver"); 164 MODULE_AUTHOR("Christian Lamparter <chunkeey@gmail.com>"); 165 MODULE_AUTHOR("Ansuel Smith <ansuelsmth@gmail.com>"); 166 MODULE_LICENSE("GPL"); 167