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(val: (mii_id << 8) | regnum, addr: data->membase + EMAC_MAC_MADR_REG); |
44 | /* pull up the phy io line */ |
45 | writel(val: 0x1, addr: data->membase + EMAC_MAC_MCMD_REG); |
46 | |
47 | /* Wait read complete */ |
48 | timeout_jiffies = jiffies + MDIO_TIMEOUT; |
49 | while (readl(addr: data->membase + EMAC_MAC_MIND_REG) & 0x1) { |
50 | if (time_is_before_jiffies(timeout_jiffies)) |
51 | return -ETIMEDOUT; |
52 | msleep(msecs: 1); |
53 | } |
54 | |
55 | /* push down the phy io line */ |
56 | writel(val: 0x0, addr: data->membase + EMAC_MAC_MCMD_REG); |
57 | /* and read data */ |
58 | value = readl(addr: 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(val: (mii_id << 8) | regnum, addr: data->membase + EMAC_MAC_MADR_REG); |
71 | /* pull up the phy io line */ |
72 | writel(val: 0x1, addr: data->membase + EMAC_MAC_MCMD_REG); |
73 | |
74 | /* Wait read complete */ |
75 | timeout_jiffies = jiffies + MDIO_TIMEOUT; |
76 | while (readl(addr: data->membase + EMAC_MAC_MIND_REG) & 0x1) { |
77 | if (time_is_before_jiffies(timeout_jiffies)) |
78 | return -ETIMEDOUT; |
79 | msleep(msecs: 1); |
80 | } |
81 | |
82 | /* push down the phy io line */ |
83 | writel(val: 0x0, addr: data->membase + EMAC_MAC_MCMD_REG); |
84 | /* and write data */ |
85 | writel(val: value, addr: 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(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(buf: bus->id, MII_BUS_ID_SIZE, fmt: "%s-mii" , dev_name(dev: &pdev->dev)); |
105 | bus->parent = &pdev->dev; |
106 | |
107 | data = bus->priv; |
108 | data->membase = devm_platform_ioremap_resource(pdev, index: 0); |
109 | if (IS_ERR(ptr: data->membase)) { |
110 | ret = PTR_ERR(ptr: data->membase); |
111 | goto err_out_free_mdiobus; |
112 | } |
113 | |
114 | data->regulator = devm_regulator_get(dev: &pdev->dev, id: "phy" ); |
115 | if (IS_ERR(ptr: data->regulator)) { |
116 | if (PTR_ERR(ptr: 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(regulator: data->regulator); |
125 | if (ret) |
126 | goto err_out_free_mdiobus; |
127 | } |
128 | |
129 | ret = of_mdiobus_register(mdio: bus, np); |
130 | if (ret < 0) |
131 | goto err_out_disable_regulator; |
132 | |
133 | platform_set_drvdata(pdev, data: bus); |
134 | |
135 | return 0; |
136 | |
137 | err_out_disable_regulator: |
138 | if (data->regulator) |
139 | regulator_disable(regulator: 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(regulator: 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 | |