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22#include <linux/init.h>
23#include <linux/kernel.h>
24#include <linux/module.h>
25#include <linux/mutex.h>
26#include <linux/phy.h>
27#include <linux/of_address.h>
28#include <linux/of_mdio.h>
29#include <linux/platform_device.h>
30#include <linux/delay.h>
31
32#define MVMDIO_SMI_DATA_SHIFT 0
33#define MVMDIO_SMI_PHY_ADDR_SHIFT 16
34#define MVMDIO_SMI_PHY_REG_SHIFT 21
35#define MVMDIO_SMI_READ_OPERATION BIT(26)
36#define MVMDIO_SMI_WRITE_OPERATION 0
37#define MVMDIO_SMI_READ_VALID BIT(27)
38#define MVMDIO_SMI_BUSY BIT(28)
39
40struct orion_mdio_dev {
41 struct mutex lock;
42 void __iomem *smireg;
43};
44
45
46
47static int orion_mdio_wait_ready(struct mii_bus *bus)
48{
49 struct orion_mdio_dev *dev = bus->priv;
50 int count;
51 u32 val;
52
53 count = 0;
54 while (1) {
55 val = readl(dev->smireg);
56 if (!(val & MVMDIO_SMI_BUSY))
57 break;
58
59 if (count > 100) {
60 dev_err(bus->parent, "Timeout: SMI busy for too long\n");
61 return -ETIMEDOUT;
62 }
63
64 udelay(10);
65 count++;
66 }
67
68 return 0;
69}
70
71static int orion_mdio_read(struct mii_bus *bus, int mii_id,
72 int regnum)
73{
74 struct orion_mdio_dev *dev = bus->priv;
75 int count;
76 u32 val;
77 int ret;
78
79 mutex_lock(&dev->lock);
80
81 ret = orion_mdio_wait_ready(bus);
82 if (ret < 0) {
83 mutex_unlock(&dev->lock);
84 return ret;
85 }
86
87 writel(((mii_id << MVMDIO_SMI_PHY_ADDR_SHIFT) |
88 (regnum << MVMDIO_SMI_PHY_REG_SHIFT) |
89 MVMDIO_SMI_READ_OPERATION),
90 dev->smireg);
91
92
93 count = 0;
94 while (1) {
95 val = readl(dev->smireg);
96 if (val & MVMDIO_SMI_READ_VALID)
97 break;
98
99 if (count > 100) {
100 dev_err(bus->parent, "Timeout when reading PHY\n");
101 mutex_unlock(&dev->lock);
102 return -ETIMEDOUT;
103 }
104
105 udelay(10);
106 count++;
107 }
108
109 mutex_unlock(&dev->lock);
110
111 return val & 0xFFFF;
112}
113
114static int orion_mdio_write(struct mii_bus *bus, int mii_id,
115 int regnum, u16 value)
116{
117 struct orion_mdio_dev *dev = bus->priv;
118 int ret;
119
120 mutex_lock(&dev->lock);
121
122 ret = orion_mdio_wait_ready(bus);
123 if (ret < 0) {
124 mutex_unlock(&dev->lock);
125 return ret;
126 }
127
128 writel(((mii_id << MVMDIO_SMI_PHY_ADDR_SHIFT) |
129 (regnum << MVMDIO_SMI_PHY_REG_SHIFT) |
130 MVMDIO_SMI_WRITE_OPERATION |
131 (value << MVMDIO_SMI_DATA_SHIFT)),
132 dev->smireg);
133
134 mutex_unlock(&dev->lock);
135
136 return 0;
137}
138
139static int orion_mdio_reset(struct mii_bus *bus)
140{
141 return 0;
142}
143
144static int orion_mdio_probe(struct platform_device *pdev)
145{
146 struct device_node *np = pdev->dev.of_node;
147 struct mii_bus *bus;
148 struct orion_mdio_dev *dev;
149 int i, ret;
150
151 bus = mdiobus_alloc_size(sizeof(struct orion_mdio_dev));
152 if (!bus) {
153 dev_err(&pdev->dev, "Cannot allocate MDIO bus\n");
154 return -ENOMEM;
155 }
156
157 bus->name = "orion_mdio_bus";
158 bus->read = orion_mdio_read;
159 bus->write = orion_mdio_write;
160 bus->reset = orion_mdio_reset;
161 snprintf(bus->id, MII_BUS_ID_SIZE, "%s-mii",
162 dev_name(&pdev->dev));
163 bus->parent = &pdev->dev;
164
165 bus->irq = kmalloc(sizeof(int) * PHY_MAX_ADDR, GFP_KERNEL);
166 if (!bus->irq) {
167 mdiobus_free(bus);
168 return -ENOMEM;
169 }
170
171 for (i = 0; i < PHY_MAX_ADDR; i++)
172 bus->irq[i] = PHY_POLL;
173
174 dev = bus->priv;
175 dev->smireg = of_iomap(pdev->dev.of_node, 0);
176 if (!dev->smireg) {
177 dev_err(&pdev->dev, "No SMI register address given in DT\n");
178 kfree(bus->irq);
179 mdiobus_free(bus);
180 return -ENODEV;
181 }
182
183 mutex_init(&dev->lock);
184
185 ret = of_mdiobus_register(bus, np);
186 if (ret < 0) {
187 dev_err(&pdev->dev, "Cannot register MDIO bus (%d)\n", ret);
188 iounmap(dev->smireg);
189 kfree(bus->irq);
190 mdiobus_free(bus);
191 return ret;
192 }
193
194 platform_set_drvdata(pdev, bus);
195
196 return 0;
197}
198
199static int orion_mdio_remove(struct platform_device *pdev)
200{
201 struct mii_bus *bus = platform_get_drvdata(pdev);
202 mdiobus_unregister(bus);
203 kfree(bus->irq);
204 mdiobus_free(bus);
205 return 0;
206}
207
208static const struct of_device_id orion_mdio_match[] = {
209 { .compatible = "marvell,orion-mdio" },
210 { }
211};
212MODULE_DEVICE_TABLE(of, orion_mdio_match);
213
214static struct platform_driver orion_mdio_driver = {
215 .probe = orion_mdio_probe,
216 .remove = orion_mdio_remove,
217 .driver = {
218 .name = "orion-mdio",
219 .of_match_table = orion_mdio_match,
220 },
221};
222
223module_platform_driver(orion_mdio_driver);
224
225MODULE_DESCRIPTION("Marvell MDIO interface driver");
226MODULE_AUTHOR("Thomas Petazzoni <thomas.petazzoni@free-electrons.com>");
227MODULE_LICENSE("GPL");
228
