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/iopoll.h> 7 #include <linux/mdio.h> 8 #include <linux/module.h> 9 #include <linux/of.h> 10 #include <linux/of_mdio.h> 11 #include <linux/phy.h> 12 #include <linux/platform_device.h> 13 14 #define DRV_NAME "mdio-aspeed" 15 16 #define ASPEED_MDIO_CTRL 0x0 17 #define ASPEED_MDIO_CTRL_FIRE BIT(31) 18 #define ASPEED_MDIO_CTRL_ST BIT(28) 19 #define ASPEED_MDIO_CTRL_ST_C45 0 20 #define ASPEED_MDIO_CTRL_ST_C22 1 21 #define ASPEED_MDIO_CTRL_OP GENMASK(27, 26) 22 #define MDIO_C22_OP_WRITE 0b01 23 #define MDIO_C22_OP_READ 0b10 24 #define ASPEED_MDIO_CTRL_PHYAD GENMASK(25, 21) 25 #define ASPEED_MDIO_CTRL_REGAD GENMASK(20, 16) 26 #define ASPEED_MDIO_CTRL_MIIWDATA GENMASK(15, 0) 27 28 #define ASPEED_MDIO_DATA 0x4 29 #define ASPEED_MDIO_DATA_MDC_THRES GENMASK(31, 24) 30 #define ASPEED_MDIO_DATA_MDIO_EDGE BIT(23) 31 #define ASPEED_MDIO_DATA_MDIO_LATCH GENMASK(22, 20) 32 #define ASPEED_MDIO_DATA_IDLE BIT(16) 33 #define ASPEED_MDIO_DATA_MIIRDATA GENMASK(15, 0) 34 35 #define ASPEED_MDIO_INTERVAL_US 100 36 #define ASPEED_MDIO_TIMEOUT_US (ASPEED_MDIO_INTERVAL_US * 10) 37 38 struct aspeed_mdio { 39 void __iomem *base; 40 }; 41 42 static int aspeed_mdio_read(struct mii_bus *bus, int addr, int regnum) 43 { 44 struct aspeed_mdio *ctx = bus->priv; 45 u32 ctrl; 46 u32 data; 47 int rc; 48 49 dev_dbg(&bus->dev, "%s: addr: %d, regnum: %d\n", __func__, addr, 50 regnum); 51 52 /* Just clause 22 for the moment */ 53 if (regnum & MII_ADDR_C45) 54 return -EOPNOTSUPP; 55 56 ctrl = ASPEED_MDIO_CTRL_FIRE 57 | FIELD_PREP(ASPEED_MDIO_CTRL_ST, ASPEED_MDIO_CTRL_ST_C22) 58 | FIELD_PREP(ASPEED_MDIO_CTRL_OP, MDIO_C22_OP_READ) 59 | FIELD_PREP(ASPEED_MDIO_CTRL_PHYAD, addr) 60 | FIELD_PREP(ASPEED_MDIO_CTRL_REGAD, regnum); 61 62 iowrite32(ctrl, ctx->base + ASPEED_MDIO_CTRL); 63 64 rc = readl_poll_timeout(ctx->base + ASPEED_MDIO_CTRL, ctrl, 65 !(ctrl & ASPEED_MDIO_CTRL_FIRE), 66 ASPEED_MDIO_INTERVAL_US, 67 ASPEED_MDIO_TIMEOUT_US); 68 if (rc < 0) 69 return rc; 70 71 rc = readl_poll_timeout(ctx->base + ASPEED_MDIO_DATA, data, 72 data & ASPEED_MDIO_DATA_IDLE, 73 ASPEED_MDIO_INTERVAL_US, 74 ASPEED_MDIO_TIMEOUT_US); 75 if (rc < 0) 76 return rc; 77 78 return FIELD_GET(ASPEED_MDIO_DATA_MIIRDATA, data); 79 } 80 81 static int aspeed_mdio_write(struct mii_bus *bus, int addr, int regnum, u16 val) 82 { 83 struct aspeed_mdio *ctx = bus->priv; 84 u32 ctrl; 85 86 dev_dbg(&bus->dev, "%s: addr: %d, regnum: %d, val: 0x%x\n", 87 __func__, addr, regnum, val); 88 89 /* Just clause 22 for the moment */ 90 if (regnum & MII_ADDR_C45) 91 return -EOPNOTSUPP; 92 93 ctrl = ASPEED_MDIO_CTRL_FIRE 94 | FIELD_PREP(ASPEED_MDIO_CTRL_ST, ASPEED_MDIO_CTRL_ST_C22) 95 | FIELD_PREP(ASPEED_MDIO_CTRL_OP, MDIO_C22_OP_WRITE) 96 | FIELD_PREP(ASPEED_MDIO_CTRL_PHYAD, addr) 97 | FIELD_PREP(ASPEED_MDIO_CTRL_REGAD, regnum) 98 | FIELD_PREP(ASPEED_MDIO_CTRL_MIIWDATA, val); 99 100 iowrite32(ctrl, ctx->base + ASPEED_MDIO_CTRL); 101 102 return readl_poll_timeout(ctx->base + ASPEED_MDIO_CTRL, ctrl, 103 !(ctrl & ASPEED_MDIO_CTRL_FIRE), 104 ASPEED_MDIO_INTERVAL_US, 105 ASPEED_MDIO_TIMEOUT_US); 106 } 107 108 static int aspeed_mdio_probe(struct platform_device *pdev) 109 { 110 struct aspeed_mdio *ctx; 111 struct mii_bus *bus; 112 int rc; 113 114 bus = devm_mdiobus_alloc_size(&pdev->dev, sizeof(*ctx)); 115 if (!bus) 116 return -ENOMEM; 117 118 ctx = bus->priv; 119 ctx->base = devm_platform_ioremap_resource(pdev, 0); 120 if (IS_ERR(ctx->base)) 121 return PTR_ERR(ctx->base); 122 123 bus->name = DRV_NAME; 124 snprintf(bus->id, MII_BUS_ID_SIZE, "%s%d", pdev->name, pdev->id); 125 bus->parent = &pdev->dev; 126 bus->read = aspeed_mdio_read; 127 bus->write = aspeed_mdio_write; 128 129 rc = of_mdiobus_register(bus, pdev->dev.of_node); 130 if (rc) { 131 dev_err(&pdev->dev, "Cannot register MDIO bus!\n"); 132 return rc; 133 } 134 135 platform_set_drvdata(pdev, bus); 136 137 return 0; 138 } 139 140 static int aspeed_mdio_remove(struct platform_device *pdev) 141 { 142 mdiobus_unregister(platform_get_drvdata(pdev)); 143 144 return 0; 145 } 146 147 static const struct of_device_id aspeed_mdio_of_match[] = { 148 { .compatible = "aspeed,ast2600-mdio", }, 149 { }, 150 }; 151 152 static struct platform_driver aspeed_mdio_driver = { 153 .driver = { 154 .name = DRV_NAME, 155 .of_match_table = aspeed_mdio_of_match, 156 }, 157 .probe = aspeed_mdio_probe, 158 .remove = aspeed_mdio_remove, 159 }; 160 161 module_platform_driver(aspeed_mdio_driver); 162 163 MODULE_AUTHOR("Andrew Jeffery <andrew@aj.id.au>"); 164 MODULE_LICENSE("GPL"); 165