tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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linux
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
31struct sun4i_mdio_data {
32 void __iomem *membase;
33 struct regulator *regulator;
34};
35
36static 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((mii_id << 8) | regnum, data->membase + EMAC_MAC_MADR_REG);
44 /* pull up the phy io line */
45 writel(0x1, data->membase + EMAC_MAC_MCMD_REG);
46
47 /* Wait read complete */
48 timeout_jiffies = jiffies + MDIO_TIMEOUT;
49 while (readl(data->membase + EMAC_MAC_MIND_REG) & 0x1) {
50 if (time_is_before_jiffies(timeout_jiffies))
51 return -ETIMEDOUT;
52 msleep(1);
53 }
54
55 /* push down the phy io line */
56 writel(0x0, data->membase + EMAC_MAC_MCMD_REG);
57 /* and read data */
58 value = readl(data->membase + EMAC_MAC_MRDD_REG);
59
60 return value;
61}
62
63static 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((mii_id << 8) | regnum, data->membase + EMAC_MAC_MADR_REG);
71 /* pull up the phy io line */
72 writel(0x1, data->membase + EMAC_MAC_MCMD_REG);
73
74 /* Wait read complete */
75 timeout_jiffies = jiffies + MDIO_TIMEOUT;
76 while (readl(data->membase + EMAC_MAC_MIND_REG) & 0x1) {
77 if (time_is_before_jiffies(timeout_jiffies))
78 return -ETIMEDOUT;
79 msleep(1);
80 }
81
82 /* push down the phy io line */
83 writel(0x0, data->membase + EMAC_MAC_MCMD_REG);
84 /* and write data */
85 writel(value, data->membase + EMAC_MAC_MWTD_REG);
86
87 return 0;
88}
89
90static 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 struct resource *res;
96 int ret;
97
98 bus = mdiobus_alloc_size(sizeof(*data));
99 if (!bus)
100 return -ENOMEM;
101
102 bus->name = "sun4i_mii_bus";
103 bus->read = &sun4i_mdio_read;
104 bus->write = &sun4i_mdio_write;
105 snprintf(bus->id, MII_BUS_ID_SIZE, "%s-mii", dev_name(&pdev->dev));
106 bus->parent = &pdev->dev;
107
108 data = bus->priv;
109 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
110 data->membase = devm_ioremap_resource(&pdev->dev, res);
111 if (IS_ERR(data->membase)) {
112 ret = PTR_ERR(data->membase);
113 goto err_out_free_mdiobus;
114 }
115
116 data->regulator = devm_regulator_get(&pdev->dev, "phy");
117 if (IS_ERR(data->regulator)) {
118 if (PTR_ERR(data->regulator) == -EPROBE_DEFER) {
119 ret = -EPROBE_DEFER;
120 goto err_out_free_mdiobus;
121 }
122
123 dev_info(&pdev->dev, "no regulator found\n");
124 data->regulator = NULL;
125 } else {
126 ret = regulator_enable(data->regulator);
127 if (ret)
128 goto err_out_free_mdiobus;
129 }
130
131 ret = of_mdiobus_register(bus, np);
132 if (ret < 0)
133 goto err_out_disable_regulator;
134
135 platform_set_drvdata(pdev, bus);
136
137 return 0;
138
139err_out_disable_regulator:
140 if (data->regulator)
141 regulator_disable(data->regulator);
142err_out_free_mdiobus:
143 mdiobus_free(bus);
144 return ret;
145}
146
147static int sun4i_mdio_remove(struct platform_device *pdev)
148{
149 struct mii_bus *bus = platform_get_drvdata(pdev);
150
151 mdiobus_unregister(bus);
152 mdiobus_free(bus);
153
154 return 0;
155}
156
157static const struct of_device_id sun4i_mdio_dt_ids[] = {
158 { .compatible = "allwinner,sun4i-a10-mdio" },
159
160 /* Deprecated */
161 { .compatible = "allwinner,sun4i-mdio" },
162 { }
163};
164MODULE_DEVICE_TABLE(of, sun4i_mdio_dt_ids);
165
166static struct platform_driver sun4i_mdio_driver = {
167 .probe = sun4i_mdio_probe,
168 .remove = sun4i_mdio_remove,
169 .driver = {
170 .name = "sun4i-mdio",
171 .of_match_table = sun4i_mdio_dt_ids,
172 },
173};
174
175module_platform_driver(sun4i_mdio_driver);
176
177MODULE_DESCRIPTION("Allwinner EMAC MDIO interface driver");
178MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
179MODULE_LICENSE("GPL v2");