1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* Copyright (C) 2019 IBM Corp. */
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>
10 #include <linux/of_mdio.h>
11 #include <linux/phy.h>
12 #include <linux/platform_device.h>
14 #define DRV_NAME "mdio-aspeed"
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)
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)
35 #define ASPEED_MDIO_INTERVAL_US 100
36 #define ASPEED_MDIO_TIMEOUT_US (ASPEED_MDIO_INTERVAL_US * 10)
42 static int aspeed_mdio_read(struct mii_bus *bus, int addr, int regnum)
44 struct aspeed_mdio *ctx = bus->priv;
49 dev_dbg(&bus->dev, "%s: addr: %d, regnum: %d\n", __func__, addr,
52 /* Just clause 22 for the moment */
53 if (regnum & MII_ADDR_C45)
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);
62 iowrite32(ctrl, ctx->base + ASPEED_MDIO_CTRL);
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);
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);
78 return FIELD_GET(ASPEED_MDIO_DATA_MIIRDATA, data);
81 static int aspeed_mdio_write(struct mii_bus *bus, int addr, int regnum, u16 val)
83 struct aspeed_mdio *ctx = bus->priv;
86 dev_dbg(&bus->dev, "%s: addr: %d, regnum: %d, val: 0x%x\n",
87 __func__, addr, regnum, val);
89 /* Just clause 22 for the moment */
90 if (regnum & MII_ADDR_C45)
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);
100 iowrite32(ctrl, ctx->base + ASPEED_MDIO_CTRL);
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);
108 static int aspeed_mdio_probe(struct platform_device *pdev)
110 struct aspeed_mdio *ctx;
114 bus = devm_mdiobus_alloc_size(&pdev->dev, sizeof(*ctx));
119 ctx->base = devm_platform_ioremap_resource(pdev, 0);
120 if (IS_ERR(ctx->base))
121 return PTR_ERR(ctx->base);
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;
129 rc = of_mdiobus_register(bus, pdev->dev.of_node);
131 dev_err(&pdev->dev, "Cannot register MDIO bus!\n");
135 platform_set_drvdata(pdev, bus);
140 static int aspeed_mdio_remove(struct platform_device *pdev)
142 mdiobus_unregister(platform_get_drvdata(pdev));
147 static const struct of_device_id aspeed_mdio_of_match[] = {
148 { .compatible = "aspeed,ast2600-mdio", },
151 MODULE_DEVICE_TABLE(of, aspeed_mdio_of_match);
153 static struct platform_driver aspeed_mdio_driver = {
156 .of_match_table = aspeed_mdio_of_match,
158 .probe = aspeed_mdio_probe,
159 .remove = aspeed_mdio_remove,
162 module_platform_driver(aspeed_mdio_driver);
164 MODULE_AUTHOR("Andrew Jeffery <andrew@aj.id.au>");
165 MODULE_LICENSE("GPL");