1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* Copyright (C) 2019 IBM Corp. */ 3 4 #include <linux/bitfield.h> 5 #include <linux/delay.h> 6 #include <linux/reset.h> 7 #include <linux/iopoll.h> 8 #include <linux/mdio.h> 9 #include <linux/module.h> 10 #include <linux/of.h> 11 #include <linux/of_mdio.h> 12 #include <linux/phy.h> 13 #include <linux/platform_device.h> 14 15 #define DRV_NAME "mdio-aspeed" 16 17 #define ASPEED_MDIO_CTRL 0x0 18 #define ASPEED_MDIO_CTRL_FIRE BIT(31) 19 #define ASPEED_MDIO_CTRL_ST BIT(28) 20 #define ASPEED_MDIO_CTRL_ST_C45 0 21 #define ASPEED_MDIO_CTRL_ST_C22 1 22 #define ASPEED_MDIO_CTRL_OP GENMASK(27, 26) 23 #define MDIO_C22_OP_WRITE 0b01 24 #define MDIO_C22_OP_READ 0b10 25 #define MDIO_C45_OP_ADDR 0b00 26 #define MDIO_C45_OP_WRITE 0b01 27 #define MDIO_C45_OP_PREAD 0b10 28 #define MDIO_C45_OP_READ 0b11 29 #define ASPEED_MDIO_CTRL_PHYAD GENMASK(25, 21) 30 #define ASPEED_MDIO_CTRL_REGAD GENMASK(20, 16) 31 #define ASPEED_MDIO_CTRL_MIIWDATA GENMASK(15, 0) 32 33 #define ASPEED_MDIO_DATA 0x4 34 #define ASPEED_MDIO_DATA_MDC_THRES GENMASK(31, 24) 35 #define ASPEED_MDIO_DATA_MDIO_EDGE BIT(23) 36 #define ASPEED_MDIO_DATA_MDIO_LATCH GENMASK(22, 20) 37 #define ASPEED_MDIO_DATA_IDLE BIT(16) 38 #define ASPEED_MDIO_DATA_MIIRDATA GENMASK(15, 0) 39 40 #define ASPEED_MDIO_INTERVAL_US 100 41 #define ASPEED_MDIO_TIMEOUT_US (ASPEED_MDIO_INTERVAL_US * 10) 42 43 struct aspeed_mdio { 44 void __iomem *base; 45 struct reset_control *reset; 46 }; 47 48 static int aspeed_mdio_op(struct mii_bus *bus, u8 st, u8 op, u8 phyad, u8 regad, 49 u16 data) 50 { 51 struct aspeed_mdio *ctx = bus->priv; 52 u32 ctrl; 53 54 dev_dbg(&bus->dev, "%s: st: %u op: %u, phyad: %u, regad: %u, data: %u\n", 55 __func__, st, op, phyad, regad, data); 56 57 ctrl = ASPEED_MDIO_CTRL_FIRE 58 | FIELD_PREP(ASPEED_MDIO_CTRL_ST, st) 59 | FIELD_PREP(ASPEED_MDIO_CTRL_OP, op) 60 | FIELD_PREP(ASPEED_MDIO_CTRL_PHYAD, phyad) 61 | FIELD_PREP(ASPEED_MDIO_CTRL_REGAD, regad) 62 | FIELD_PREP(ASPEED_MDIO_DATA_MIIRDATA, data); 63 64 iowrite32(ctrl, ctx->base + ASPEED_MDIO_CTRL); 65 66 return readl_poll_timeout(ctx->base + ASPEED_MDIO_CTRL, ctrl, 67 !(ctrl & ASPEED_MDIO_CTRL_FIRE), 68 ASPEED_MDIO_INTERVAL_US, 69 ASPEED_MDIO_TIMEOUT_US); 70 } 71 72 static int aspeed_mdio_get_data(struct mii_bus *bus) 73 { 74 struct aspeed_mdio *ctx = bus->priv; 75 u32 data; 76 int rc; 77 78 rc = readl_poll_timeout(ctx->base + ASPEED_MDIO_DATA, data, 79 data & ASPEED_MDIO_DATA_IDLE, 80 ASPEED_MDIO_INTERVAL_US, 81 ASPEED_MDIO_TIMEOUT_US); 82 if (rc < 0) 83 return rc; 84 85 return FIELD_GET(ASPEED_MDIO_DATA_MIIRDATA, data); 86 } 87 88 static int aspeed_mdio_read_c22(struct mii_bus *bus, int addr, int regnum) 89 { 90 int rc; 91 92 rc = aspeed_mdio_op(bus, ASPEED_MDIO_CTRL_ST_C22, MDIO_C22_OP_READ, 93 addr, regnum, 0); 94 if (rc < 0) 95 return rc; 96 97 return aspeed_mdio_get_data(bus); 98 } 99 100 static int aspeed_mdio_write_c22(struct mii_bus *bus, int addr, int regnum, 101 u16 val) 102 { 103 return aspeed_mdio_op(bus, ASPEED_MDIO_CTRL_ST_C22, MDIO_C22_OP_WRITE, 104 addr, regnum, val); 105 } 106 107 static int aspeed_mdio_read_c45(struct mii_bus *bus, int addr, int devad, 108 int regnum) 109 { 110 int rc; 111 112 rc = aspeed_mdio_op(bus, ASPEED_MDIO_CTRL_ST_C45, MDIO_C45_OP_ADDR, 113 addr, devad, regnum); 114 if (rc < 0) 115 return rc; 116 117 rc = aspeed_mdio_op(bus, ASPEED_MDIO_CTRL_ST_C45, MDIO_C45_OP_READ, 118 addr, devad, 0); 119 if (rc < 0) 120 return rc; 121 122 return aspeed_mdio_get_data(bus); 123 } 124 125 static int aspeed_mdio_write_c45(struct mii_bus *bus, int addr, int devad, 126 int regnum, u16 val) 127 { 128 int rc; 129 130 rc = aspeed_mdio_op(bus, ASPEED_MDIO_CTRL_ST_C45, MDIO_C45_OP_ADDR, 131 addr, devad, regnum); 132 if (rc < 0) 133 return rc; 134 135 return aspeed_mdio_op(bus, ASPEED_MDIO_CTRL_ST_C45, MDIO_C45_OP_WRITE, 136 addr, devad, val); 137 } 138 139 static int aspeed_mdio_probe(struct platform_device *pdev) 140 { 141 struct aspeed_mdio *ctx; 142 struct mii_bus *bus; 143 int rc; 144 145 bus = devm_mdiobus_alloc_size(&pdev->dev, sizeof(*ctx)); 146 if (!bus) 147 return -ENOMEM; 148 149 ctx = bus->priv; 150 ctx->base = devm_platform_ioremap_resource(pdev, 0); 151 if (IS_ERR(ctx->base)) 152 return PTR_ERR(ctx->base); 153 154 ctx->reset = devm_reset_control_get_optional_shared(&pdev->dev, NULL); 155 if (IS_ERR(ctx->reset)) 156 return PTR_ERR(ctx->reset); 157 158 reset_control_deassert(ctx->reset); 159 160 bus->name = DRV_NAME; 161 snprintf(bus->id, MII_BUS_ID_SIZE, "%s%d", pdev->name, pdev->id); 162 bus->parent = &pdev->dev; 163 bus->read = aspeed_mdio_read_c22; 164 bus->write = aspeed_mdio_write_c22; 165 bus->read_c45 = aspeed_mdio_read_c45; 166 bus->write_c45 = aspeed_mdio_write_c45; 167 168 rc = of_mdiobus_register(bus, pdev->dev.of_node); 169 if (rc) { 170 dev_err(&pdev->dev, "Cannot register MDIO bus!\n"); 171 reset_control_assert(ctx->reset); 172 return rc; 173 } 174 175 platform_set_drvdata(pdev, bus); 176 177 return 0; 178 } 179 180 static void aspeed_mdio_remove(struct platform_device *pdev) 181 { 182 struct mii_bus *bus = (struct mii_bus *)platform_get_drvdata(pdev); 183 struct aspeed_mdio *ctx = bus->priv; 184 185 reset_control_assert(ctx->reset); 186 mdiobus_unregister(bus); 187 } 188 189 static const struct of_device_id aspeed_mdio_of_match[] = { 190 { .compatible = "aspeed,ast2600-mdio", }, 191 { }, 192 }; 193 MODULE_DEVICE_TABLE(of, aspeed_mdio_of_match); 194 195 static struct platform_driver aspeed_mdio_driver = { 196 .driver = { 197 .name = DRV_NAME, 198 .of_match_table = aspeed_mdio_of_match, 199 }, 200 .probe = aspeed_mdio_probe, 201 .remove_new = aspeed_mdio_remove, 202 }; 203 204 module_platform_driver(aspeed_mdio_driver); 205 206 MODULE_AUTHOR("Andrew Jeffery <andrew@aj.id.au>"); 207 MODULE_LICENSE("GPL"); 208 MODULE_DESCRIPTION("ASPEED MDIO bus controller"); 209