tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/* MOXA ART Ethernet (RTL8201CP) MDIO interface driver
2 *
3 * Copyright (C) 2013 Jonas Jensen <jonas.jensen@gmail.com>
4 *
5 * This file is licensed under the terms of the GNU General Public
6 * License version 2. This program is licensed "as is" without any
7 * warranty of any kind, whether express or implied.
8 */
9
10#include <linux/delay.h>
11#include <linux/init.h>
12#include <linux/kernel.h>
13#include <linux/module.h>
14#include <linux/mutex.h>
15#include <linux/of_address.h>
16#include <linux/of_mdio.h>
17#include <linux/phy.h>
18#include <linux/platform_device.h>
19#include <linux/regulator/consumer.h>
20
21#define REG_PHY_CTRL 0
22#define REG_PHY_WRITE_DATA 4
23
24/* REG_PHY_CTRL */
25#define MIIWR BIT(27) /* init write sequence (auto cleared)*/
26#define MIIRD BIT(26)
27#define REGAD_MASK 0x3e00000
28#define PHYAD_MASK 0x1f0000
29#define MIIRDATA_MASK 0xffff
30
31/* REG_PHY_WRITE_DATA */
32#define MIIWDATA_MASK 0xffff
33
34struct moxart_mdio_data {
35 void __iomem *base;
36};
37
38static int moxart_mdio_read(struct mii_bus *bus, int mii_id, int regnum)
39{
40 struct moxart_mdio_data *data = bus->priv;
41 u32 ctrl = 0;
42 unsigned int count = 5;
43
44 dev_dbg(&bus->dev, "%s\n", __func__);
45
46 ctrl |= MIIRD | ((mii_id << 16) & PHYAD_MASK) |
47 ((regnum << 21) & REGAD_MASK);
48
49 writel(ctrl, data->base + REG_PHY_CTRL);
50
51 do {
52 ctrl = readl(data->base + REG_PHY_CTRL);
53
54 if (!(ctrl & MIIRD))
55 return ctrl & MIIRDATA_MASK;
56
57 mdelay(10);
58 count--;
59 } while (count > 0);
60
61 dev_dbg(&bus->dev, "%s timed out\n", __func__);
62
63 return -ETIMEDOUT;
64}
65
66static int moxart_mdio_write(struct mii_bus *bus, int mii_id,
67 int regnum, u16 value)
68{
69 struct moxart_mdio_data *data = bus->priv;
70 u32 ctrl = 0;
71 unsigned int count = 5;
72
73 dev_dbg(&bus->dev, "%s\n", __func__);
74
75 ctrl |= MIIWR | ((mii_id << 16) & PHYAD_MASK) |
76 ((regnum << 21) & REGAD_MASK);
77
78 value &= MIIWDATA_MASK;
79
80 writel(value, data->base + REG_PHY_WRITE_DATA);
81 writel(ctrl, data->base + REG_PHY_CTRL);
82
83 do {
84 ctrl = readl(data->base + REG_PHY_CTRL);
85
86 if (!(ctrl & MIIWR))
87 return 0;
88
89 mdelay(10);
90 count--;
91 } while (count > 0);
92
93 dev_dbg(&bus->dev, "%s timed out\n", __func__);
94
95 return -ETIMEDOUT;
96}
97
98static int moxart_mdio_reset(struct mii_bus *bus)
99{
100 int data, i;
101
102 for (i = 0; i < PHY_MAX_ADDR; i++) {
103 data = moxart_mdio_read(bus, i, MII_BMCR);
104 if (data < 0)
105 continue;
106
107 data |= BMCR_RESET;
108 if (moxart_mdio_write(bus, i, MII_BMCR, data) < 0)
109 continue;
110 }
111
112 return 0;
113}
114
115static int moxart_mdio_probe(struct platform_device *pdev)
116{
117 struct device_node *np = pdev->dev.of_node;
118 struct mii_bus *bus;
119 struct moxart_mdio_data *data;
120 struct resource *res;
121 int ret, i;
122
123 bus = mdiobus_alloc_size(sizeof(*data));
124 if (!bus)
125 return -ENOMEM;
126
127 bus->name = "MOXA ART Ethernet MII";
128 bus->read = &moxart_mdio_read;
129 bus->write = &moxart_mdio_write;
130 bus->reset = &moxart_mdio_reset;
131 snprintf(bus->id, MII_BUS_ID_SIZE, "%s-%d-mii", pdev->name, pdev->id);
132 bus->parent = &pdev->dev;
133
134 bus->irq = devm_kzalloc(&pdev->dev, sizeof(int) * PHY_MAX_ADDR,
135 GFP_KERNEL);
136 if (!bus->irq) {
137 ret = -ENOMEM;
138 goto err_out_free_mdiobus;
139 }
140
141 /* Setting PHY_IGNORE_INTERRUPT here even if it has no effect,
142 * of_mdiobus_register() sets these PHY_POLL.
143 * Ideally, the interrupt from MAC controller could be used to
144 * detect link state changes, not polling, i.e. if there was
145 * a way phy_driver could set PHY_HAS_INTERRUPT but have that
146 * interrupt handled in ethernet drivercode.
147 */
148 for (i = 0; i < PHY_MAX_ADDR; i++)
149 bus->irq[i] = PHY_IGNORE_INTERRUPT;
150
151 data = bus->priv;
152 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
153 data->base = devm_ioremap_resource(&pdev->dev, res);
154 if (IS_ERR(data->base)) {
155 ret = PTR_ERR(data->base);
156 goto err_out_free_mdiobus;
157 }
158
159 ret = of_mdiobus_register(bus, np);
160 if (ret < 0)
161 goto err_out_free_mdiobus;
162
163 platform_set_drvdata(pdev, bus);
164
165 return 0;
166
167err_out_free_mdiobus:
168 mdiobus_free(bus);
169 return ret;
170}
171
172static int moxart_mdio_remove(struct platform_device *pdev)
173{
174 struct mii_bus *bus = platform_get_drvdata(pdev);
175
176 mdiobus_unregister(bus);
177 mdiobus_free(bus);
178
179 return 0;
180}
181
182static const struct of_device_id moxart_mdio_dt_ids[] = {
183 { .compatible = "moxa,moxart-mdio" },
184 { }
185};
186MODULE_DEVICE_TABLE(of, moxart_mdio_dt_ids);
187
188static struct platform_driver moxart_mdio_driver = {
189 .probe = moxart_mdio_probe,
190 .remove = moxart_mdio_remove,
191 .driver = {
192 .name = "moxart-mdio",
193 .of_match_table = moxart_mdio_dt_ids,
194 },
195};
196
197module_platform_driver(moxart_mdio_driver);
198
199MODULE_DESCRIPTION("MOXA ART MDIO interface driver");
200MODULE_AUTHOR("Jonas Jensen <jonas.jensen@gmail.com>");
201MODULE_LICENSE("GPL");