1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20#include <linux/kernel.h>
21#include <linux/module.h>
22#include <linux/mutex.h>
23#include <linux/phy.h>
24#include <linux/interrupt.h>
25#include <linux/platform_device.h>
26#include <linux/delay.h>
27#include <linux/io.h>
28#include <linux/clk.h>
29#include <linux/of_mdio.h>
30#include <linux/sched.h>
31#include <linux/wait.h>
32
33#define MVMDIO_SMI_DATA_SHIFT 0
34#define MVMDIO_SMI_PHY_ADDR_SHIFT 16
35#define MVMDIO_SMI_PHY_REG_SHIFT 21
36#define MVMDIO_SMI_READ_OPERATION BIT(26)
37#define MVMDIO_SMI_WRITE_OPERATION 0
38#define MVMDIO_SMI_READ_VALID BIT(27)
39#define MVMDIO_SMI_BUSY BIT(28)
40#define MVMDIO_ERR_INT_CAUSE 0x007C
41#define MVMDIO_ERR_INT_SMI_DONE 0x00000010
42#define MVMDIO_ERR_INT_MASK 0x0080
43
44
45
46
47
48
49#define MVMDIO_SMI_TIMEOUT 1000
50#define MVMDIO_SMI_POLL_INTERVAL_MIN 45
51#define MVMDIO_SMI_POLL_INTERVAL_MAX 55
52
53struct orion_mdio_dev {
54 struct mutex lock;
55 void __iomem *regs;
56 struct clk *clk;
57
58
59
60
61
62
63 int err_interrupt;
64 wait_queue_head_t smi_busy_wait;
65};
66
67static int orion_mdio_smi_is_done(struct orion_mdio_dev *dev)
68{
69 return !(readl(dev->regs) & MVMDIO_SMI_BUSY);
70}
71
72
73
74static int orion_mdio_wait_ready(struct mii_bus *bus)
75{
76 struct orion_mdio_dev *dev = bus->priv;
77 unsigned long timeout = usecs_to_jiffies(MVMDIO_SMI_TIMEOUT);
78 unsigned long end = jiffies + timeout;
79 int timedout = 0;
80
81 while (1) {
82 if (orion_mdio_smi_is_done(dev))
83 return 0;
84 else if (timedout)
85 break;
86
87 if (dev->err_interrupt <= 0) {
88 usleep_range(MVMDIO_SMI_POLL_INTERVAL_MIN,
89 MVMDIO_SMI_POLL_INTERVAL_MAX);
90
91 if (time_is_before_jiffies(end))
92 ++timedout;
93 } else {
94
95
96
97
98 if (timeout < 2)
99 timeout = 2;
100 wait_event_timeout(dev->smi_busy_wait,
101 orion_mdio_smi_is_done(dev),
102 timeout);
103
104 ++timedout;
105 }
106 }
107
108 dev_err(bus->parent, "Timeout: SMI busy for too long\n");
109 return -ETIMEDOUT;
110}
111
112static int orion_mdio_read(struct mii_bus *bus, int mii_id,
113 int regnum)
114{
115 struct orion_mdio_dev *dev = bus->priv;
116 u32 val;
117 int ret;
118
119 mutex_lock(&dev->lock);
120
121 ret = orion_mdio_wait_ready(bus);
122 if (ret < 0)
123 goto out;
124
125 writel(((mii_id << MVMDIO_SMI_PHY_ADDR_SHIFT) |
126 (regnum << MVMDIO_SMI_PHY_REG_SHIFT) |
127 MVMDIO_SMI_READ_OPERATION),
128 dev->regs);
129
130 ret = orion_mdio_wait_ready(bus);
131 if (ret < 0)
132 goto out;
133
134 val = readl(dev->regs);
135 if (!(val & MVMDIO_SMI_READ_VALID)) {
136 dev_err(bus->parent, "SMI bus read not valid\n");
137 ret = -ENODEV;
138 goto out;
139 }
140
141 ret = val & 0xFFFF;
142out:
143 mutex_unlock(&dev->lock);
144 return ret;
145}
146
147static int orion_mdio_write(struct mii_bus *bus, int mii_id,
148 int regnum, u16 value)
149{
150 struct orion_mdio_dev *dev = bus->priv;
151 int ret;
152
153 mutex_lock(&dev->lock);
154
155 ret = orion_mdio_wait_ready(bus);
156 if (ret < 0)
157 goto out;
158
159 writel(((mii_id << MVMDIO_SMI_PHY_ADDR_SHIFT) |
160 (regnum << MVMDIO_SMI_PHY_REG_SHIFT) |
161 MVMDIO_SMI_WRITE_OPERATION |
162 (value << MVMDIO_SMI_DATA_SHIFT)),
163 dev->regs);
164
165out:
166 mutex_unlock(&dev->lock);
167 return ret;
168}
169
170static irqreturn_t orion_mdio_err_irq(int irq, void *dev_id)
171{
172 struct orion_mdio_dev *dev = dev_id;
173
174 if (readl(dev->regs + MVMDIO_ERR_INT_CAUSE) &
175 MVMDIO_ERR_INT_SMI_DONE) {
176 writel(~MVMDIO_ERR_INT_SMI_DONE,
177 dev->regs + MVMDIO_ERR_INT_CAUSE);
178 wake_up(&dev->smi_busy_wait);
179 return IRQ_HANDLED;
180 }
181
182 return IRQ_NONE;
183}
184
185static int orion_mdio_probe(struct platform_device *pdev)
186{
187 struct resource *r;
188 struct mii_bus *bus;
189 struct orion_mdio_dev *dev;
190 int i, ret;
191
192 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
193 if (!r) {
194 dev_err(&pdev->dev, "No SMI register address given\n");
195 return -ENODEV;
196 }
197
198 bus = devm_mdiobus_alloc_size(&pdev->dev,
199 sizeof(struct orion_mdio_dev));
200 if (!bus)
201 return -ENOMEM;
202
203 bus->name = "orion_mdio_bus";
204 bus->read = orion_mdio_read;
205 bus->write = orion_mdio_write;
206 snprintf(bus->id, MII_BUS_ID_SIZE, "%s-mii",
207 dev_name(&pdev->dev));
208 bus->parent = &pdev->dev;
209
210 bus->irq = devm_kmalloc_array(&pdev->dev, PHY_MAX_ADDR, sizeof(int),
211 GFP_KERNEL);
212 if (!bus->irq)
213 return -ENOMEM;
214
215 for (i = 0; i < PHY_MAX_ADDR; i++)
216 bus->irq[i] = PHY_POLL;
217
218 dev = bus->priv;
219 dev->regs = devm_ioremap(&pdev->dev, r->start, resource_size(r));
220 if (!dev->regs) {
221 dev_err(&pdev->dev, "Unable to remap SMI register\n");
222 ret = -ENODEV;
223 goto out_mdio;
224 }
225
226 init_waitqueue_head(&dev->smi_busy_wait);
227
228 dev->clk = devm_clk_get(&pdev->dev, NULL);
229 if (!IS_ERR(dev->clk))
230 clk_prepare_enable(dev->clk);
231
232 dev->err_interrupt = platform_get_irq(pdev, 0);
233 if (dev->err_interrupt > 0) {
234 ret = devm_request_irq(&pdev->dev, dev->err_interrupt,
235 orion_mdio_err_irq,
236 IRQF_SHARED, pdev->name, dev);
237 if (ret)
238 goto out_mdio;
239
240 writel(MVMDIO_ERR_INT_SMI_DONE,
241 dev->regs + MVMDIO_ERR_INT_MASK);
242
243 } else if (dev->err_interrupt == -EPROBE_DEFER) {
244 return -EPROBE_DEFER;
245 }
246
247 mutex_init(&dev->lock);
248
249 if (pdev->dev.of_node)
250 ret = of_mdiobus_register(bus, pdev->dev.of_node);
251 else
252 ret = mdiobus_register(bus);
253 if (ret < 0) {
254 dev_err(&pdev->dev, "Cannot register MDIO bus (%d)\n", ret);
255 goto out_mdio;
256 }
257
258 platform_set_drvdata(pdev, bus);
259
260 return 0;
261
262out_mdio:
263 if (!IS_ERR(dev->clk))
264 clk_disable_unprepare(dev->clk);
265 return ret;
266}
267
268static int orion_mdio_remove(struct platform_device *pdev)
269{
270 struct mii_bus *bus = platform_get_drvdata(pdev);
271 struct orion_mdio_dev *dev = bus->priv;
272
273 writel(0, dev->regs + MVMDIO_ERR_INT_MASK);
274 mdiobus_unregister(bus);
275 if (!IS_ERR(dev->clk))
276 clk_disable_unprepare(dev->clk);
277
278 return 0;
279}
280
281static const struct of_device_id orion_mdio_match[] = {
282 { .compatible = "marvell,orion-mdio" },
283 { }
284};
285MODULE_DEVICE_TABLE(of, orion_mdio_match);
286
287static struct platform_driver orion_mdio_driver = {
288 .probe = orion_mdio_probe,
289 .remove = orion_mdio_remove,
290 .driver = {
291 .name = "orion-mdio",
292 .of_match_table = orion_mdio_match,
293 },
294};
295
296module_platform_driver(orion_mdio_driver);
297
298MODULE_DESCRIPTION("Marvell MDIO interface driver");
299MODULE_AUTHOR("Thomas Petazzoni <thomas.petazzoni@free-electrons.com>");
300MODULE_LICENSE("GPL");
301MODULE_ALIAS("platform:orion-mdio");
302
