tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * Allwinner EMAC MDIO interface driver
3 *
4 * Copyright 2012-2013 Stefan Roese <sr@denx.de>
5 * Copyright 2013 Maxime Ripard <maxime.ripard@free-electrons.com>
6 *
7 * Based on the Linux driver provided by Allwinner:
8 * Copyright (C) 1997 Sten Wang
9 *
10 * This file is licensed under the terms of the GNU General Public
11 * License version 2. This program is licensed "as is" without any
12 * warranty of any kind, whether express or implied.
13 */
14
15#include <linux/delay.h>
16#include <linux/kernel.h>
17#include <linux/module.h>
18#include <linux/mutex.h>
19#include <linux/of_address.h>
20#include <linux/of_mdio.h>
21#include <linux/phy.h>
22#include <linux/platform_device.h>
23#include <linux/regulator/consumer.h>
24
25#define EMAC_MAC_MCMD_REG (0x00)
26#define EMAC_MAC_MADR_REG (0x04)
27#define EMAC_MAC_MWTD_REG (0x08)
28#define EMAC_MAC_MRDD_REG (0x0c)
29#define EMAC_MAC_MIND_REG (0x10)
30#define EMAC_MAC_SSRR_REG (0x14)
31
32#define MDIO_TIMEOUT (msecs_to_jiffies(100))
33
34struct sun4i_mdio_data {
35 void __iomem *membase;
36 struct regulator *regulator;
37};
38
39static int sun4i_mdio_read(struct mii_bus *bus, int mii_id, int regnum)
40{
41 struct sun4i_mdio_data *data = bus->priv;
42 unsigned long timeout_jiffies;
43 int value;
44
45 /* issue the phy address and reg */
46 writel((mii_id << 8) | regnum, data->membase + EMAC_MAC_MADR_REG);
47 /* pull up the phy io line */
48 writel(0x1, data->membase + EMAC_MAC_MCMD_REG);
49
50 /* Wait read complete */
51 timeout_jiffies = jiffies + MDIO_TIMEOUT;
52 while (readl(data->membase + EMAC_MAC_MIND_REG) & 0x1) {
53 if (time_is_before_jiffies(timeout_jiffies))
54 return -ETIMEDOUT;
55 msleep(1);
56 }
57
58 /* push down the phy io line */
59 writel(0x0, data->membase + EMAC_MAC_MCMD_REG);
60 /* and read data */
61 value = readl(data->membase + EMAC_MAC_MRDD_REG);
62
63 return value;
64}
65
66static int sun4i_mdio_write(struct mii_bus *bus, int mii_id, int regnum,
67 u16 value)
68{
69 struct sun4i_mdio_data *data = bus->priv;
70 unsigned long timeout_jiffies;
71
72 /* issue the phy address and reg */
73 writel((mii_id << 8) | regnum, data->membase + EMAC_MAC_MADR_REG);
74 /* pull up the phy io line */
75 writel(0x1, data->membase + EMAC_MAC_MCMD_REG);
76
77 /* Wait read complete */
78 timeout_jiffies = jiffies + MDIO_TIMEOUT;
79 while (readl(data->membase + EMAC_MAC_MIND_REG) & 0x1) {
80 if (time_is_before_jiffies(timeout_jiffies))
81 return -ETIMEDOUT;
82 msleep(1);
83 }
84
85 /* push down the phy io line */
86 writel(0x0, data->membase + EMAC_MAC_MCMD_REG);
87 /* and write data */
88 writel(value, data->membase + EMAC_MAC_MWTD_REG);
89
90 return 0;
91}
92
93static int sun4i_mdio_probe(struct platform_device *pdev)
94{
95 struct device_node *np = pdev->dev.of_node;
96 struct mii_bus *bus;
97 struct sun4i_mdio_data *data;
98 struct resource *res;
99 int ret;
100
101 bus = mdiobus_alloc_size(sizeof(*data));
102 if (!bus)
103 return -ENOMEM;
104
105 bus->name = "sun4i_mii_bus";
106 bus->read = &sun4i_mdio_read;
107 bus->write = &sun4i_mdio_write;
108 snprintf(bus->id, MII_BUS_ID_SIZE, "%s-mii", dev_name(&pdev->dev));
109 bus->parent = &pdev->dev;
110
111 data = bus->priv;
112 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
113 data->membase = devm_ioremap_resource(&pdev->dev, res);
114 if (IS_ERR(data->membase)) {
115 ret = PTR_ERR(data->membase);
116 goto err_out_free_mdiobus;
117 }
118
119 data->regulator = devm_regulator_get(&pdev->dev, "phy");
120 if (IS_ERR(data->regulator)) {
121 if (PTR_ERR(data->regulator) == -EPROBE_DEFER)
122 return -EPROBE_DEFER;
123
124 dev_info(&pdev->dev, "no regulator found\n");
125 data->regulator = NULL;
126 } else {
127 ret = regulator_enable(data->regulator);
128 if (ret)
129 goto err_out_free_mdiobus;
130 }
131
132 ret = of_mdiobus_register(bus, np);
133 if (ret < 0)
134 goto err_out_disable_regulator;
135
136 platform_set_drvdata(pdev, bus);
137
138 return 0;
139
140err_out_disable_regulator:
141 if (data->regulator)
142 regulator_disable(data->regulator);
143err_out_free_mdiobus:
144 mdiobus_free(bus);
145 return ret;
146}
147
148static int sun4i_mdio_remove(struct platform_device *pdev)
149{
150 struct mii_bus *bus = platform_get_drvdata(pdev);
151
152 mdiobus_unregister(bus);
153 mdiobus_free(bus);
154
155 return 0;
156}
157
158static const struct of_device_id sun4i_mdio_dt_ids[] = {
159 { .compatible = "allwinner,sun4i-a10-mdio" },
160
161 /* Deprecated */
162 { .compatible = "allwinner,sun4i-mdio" },
163 { }
164};
165MODULE_DEVICE_TABLE(of, sun4i_mdio_dt_ids);
166
167static struct platform_driver sun4i_mdio_driver = {
168 .probe = sun4i_mdio_probe,
169 .remove = sun4i_mdio_remove,
170 .driver = {
171 .name = "sun4i-mdio",
172 .of_match_table = sun4i_mdio_dt_ids,
173 },
174};
175
176module_platform_driver(sun4i_mdio_driver);
177
178MODULE_DESCRIPTION("Allwinner EMAC MDIO interface driver");
179MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
180MODULE_LICENSE("GPL");