1 /*
2 * Driver for the MDIO interface of Marvell network interfaces.
3 *
4 * Since the MDIO interface of Marvell network interfaces is shared
5 * between all network interfaces, having a single driver allows to
6 * handle concurrent accesses properly (you may have four Ethernet
7 * ports, but they in fact share the same SMI interface to access
8 * the MDIO bus). This driver is currently used by the mvneta and
9 * mv643xx_eth drivers.
10 *
11 * Copyright (C) 2012 Marvell
12 *
13 * Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
14 *
15 * This file is licensed under the terms of the GNU General Public
16 * License version 2. This program is licensed "as is" without any
17 * warranty of any kind, whether express or implied.
18 */
19
20 #include <linux/acpi.h>
21 #include <linux/acpi_mdio.h>
22 #include <linux/clk.h>
23 #include <linux/delay.h>
24 #include <linux/interrupt.h>
25 #include <linux/io.h>
26 #include <linux/kernel.h>
27 #include <linux/module.h>
28 #include <linux/of_device.h>
29 #include <linux/of_mdio.h>
30 #include <linux/phy.h>
31 #include <linux/platform_device.h>
32 #include <linux/sched.h>
33 #include <linux/wait.h>
34
35 #define MVMDIO_SMI_DATA_SHIFT 0
36 #define MVMDIO_SMI_PHY_ADDR_SHIFT 16
37 #define MVMDIO_SMI_PHY_REG_SHIFT 21
38 #define MVMDIO_SMI_READ_OPERATION BIT(26)
39 #define MVMDIO_SMI_WRITE_OPERATION 0
40 #define MVMDIO_SMI_READ_VALID BIT(27)
41 #define MVMDIO_SMI_BUSY BIT(28)
42 #define MVMDIO_ERR_INT_CAUSE 0x007C
43 #define MVMDIO_ERR_INT_SMI_DONE 0x00000010
44 #define MVMDIO_ERR_INT_MASK 0x0080
45
46 #define MVMDIO_XSMI_MGNT_REG 0x0
47 #define MVMDIO_XSMI_PHYADDR_SHIFT 16
48 #define MVMDIO_XSMI_DEVADDR_SHIFT 21
49 #define MVMDIO_XSMI_WRITE_OPERATION (0x5 << 26)
50 #define MVMDIO_XSMI_READ_OPERATION (0x7 << 26)
51 #define MVMDIO_XSMI_READ_VALID BIT(29)
52 #define MVMDIO_XSMI_BUSY BIT(30)
53 #define MVMDIO_XSMI_ADDR_REG 0x8
54
55 /*
56 * SMI Timeout measurements:
57 * - Kirkwood 88F6281 (Globalscale Dreamplug): 45us to 95us (Interrupt)
58 * - Armada 370 (Globalscale Mirabox): 41us to 43us (Polled)
59 */
60 #define MVMDIO_SMI_TIMEOUT 1000 /* 1000us = 1ms */
61 #define MVMDIO_SMI_POLL_INTERVAL_MIN 45
62 #define MVMDIO_SMI_POLL_INTERVAL_MAX 55
63
64 #define MVMDIO_XSMI_POLL_INTERVAL_MIN 150
65 #define MVMDIO_XSMI_POLL_INTERVAL_MAX 160
66
67 struct orion_mdio_dev {
68 void __iomem *regs;
69 struct clk *clk[4];
70 /*
71 * If we have access to the error interrupt pin (which is
72 * somewhat misnamed as it not only reflects internal errors
73 * but also reflects SMI completion), use that to wait for
74 * SMI access completion instead of polling the SMI busy bit.
75 */
76 int err_interrupt;
77 wait_queue_head_t smi_busy_wait;
78 };
79
80 enum orion_mdio_bus_type {
81 BUS_TYPE_SMI,
82 BUS_TYPE_XSMI
83 };
84
85 struct orion_mdio_ops {
86 int (*is_done)(struct orion_mdio_dev *);
87 unsigned int poll_interval_min;
88 unsigned int poll_interval_max;
89 };
90
91 /* Wait for the SMI unit to be ready for another operation
92 */
orion_mdio_wait_ready(const struct orion_mdio_ops * ops,struct mii_bus * bus)93 static int orion_mdio_wait_ready(const struct orion_mdio_ops *ops,
94 struct mii_bus *bus)
95 {
96 struct orion_mdio_dev *dev = bus->priv;
97 unsigned long timeout = usecs_to_jiffies(MVMDIO_SMI_TIMEOUT);
98 unsigned long end = jiffies + timeout;
99 int timedout = 0;
100
101 while (1) {
102 if (ops->is_done(dev))
103 return 0;
104 else if (timedout)
105 break;
106
107 if (dev->err_interrupt <= 0) {
108 usleep_range(ops->poll_interval_min,
109 ops->poll_interval_max);
110
111 if (time_is_before_jiffies(end))
112 ++timedout;
113 } else {
114 /* wait_event_timeout does not guarantee a delay of at
115 * least one whole jiffie, so timeout must be no less
116 * than two.
117 */
118 if (timeout < 2)
119 timeout = 2;
120 wait_event_timeout(dev->smi_busy_wait,
121 ops->is_done(dev), timeout);
122
123 ++timedout;
124 }
125 }
126
127 dev_err(bus->parent, "Timeout: SMI busy for too long\n");
128 return -ETIMEDOUT;
129 }
130
orion_mdio_smi_is_done(struct orion_mdio_dev * dev)131 static int orion_mdio_smi_is_done(struct orion_mdio_dev *dev)
132 {
133 return !(readl(dev->regs) & MVMDIO_SMI_BUSY);
134 }
135
136 static const struct orion_mdio_ops orion_mdio_smi_ops = {
137 .is_done = orion_mdio_smi_is_done,
138 .poll_interval_min = MVMDIO_SMI_POLL_INTERVAL_MIN,
139 .poll_interval_max = MVMDIO_SMI_POLL_INTERVAL_MAX,
140 };
141
orion_mdio_smi_read(struct mii_bus * bus,int mii_id,int regnum)142 static int orion_mdio_smi_read(struct mii_bus *bus, int mii_id,
143 int regnum)
144 {
145 struct orion_mdio_dev *dev = bus->priv;
146 u32 val;
147 int ret;
148
149 if (regnum & MII_ADDR_C45)
150 return -EOPNOTSUPP;
151
152 ret = orion_mdio_wait_ready(&orion_mdio_smi_ops, bus);
153 if (ret < 0)
154 return ret;
155
156 writel(((mii_id << MVMDIO_SMI_PHY_ADDR_SHIFT) |
157 (regnum << MVMDIO_SMI_PHY_REG_SHIFT) |
158 MVMDIO_SMI_READ_OPERATION),
159 dev->regs);
160
161 ret = orion_mdio_wait_ready(&orion_mdio_smi_ops, bus);
162 if (ret < 0)
163 return ret;
164
165 val = readl(dev->regs);
166 if (!(val & MVMDIO_SMI_READ_VALID)) {
167 dev_err(bus->parent, "SMI bus read not valid\n");
168 return -ENODEV;
169 }
170
171 return val & GENMASK(15, 0);
172 }
173
orion_mdio_smi_write(struct mii_bus * bus,int mii_id,int regnum,u16 value)174 static int orion_mdio_smi_write(struct mii_bus *bus, int mii_id,
175 int regnum, u16 value)
176 {
177 struct orion_mdio_dev *dev = bus->priv;
178 int ret;
179
180 if (regnum & MII_ADDR_C45)
181 return -EOPNOTSUPP;
182
183 ret = orion_mdio_wait_ready(&orion_mdio_smi_ops, bus);
184 if (ret < 0)
185 return ret;
186
187 writel(((mii_id << MVMDIO_SMI_PHY_ADDR_SHIFT) |
188 (regnum << MVMDIO_SMI_PHY_REG_SHIFT) |
189 MVMDIO_SMI_WRITE_OPERATION |
190 (value << MVMDIO_SMI_DATA_SHIFT)),
191 dev->regs);
192
193 return 0;
194 }
195
orion_mdio_xsmi_is_done(struct orion_mdio_dev * dev)196 static int orion_mdio_xsmi_is_done(struct orion_mdio_dev *dev)
197 {
198 return !(readl(dev->regs + MVMDIO_XSMI_MGNT_REG) & MVMDIO_XSMI_BUSY);
199 }
200
201 static const struct orion_mdio_ops orion_mdio_xsmi_ops = {
202 .is_done = orion_mdio_xsmi_is_done,
203 .poll_interval_min = MVMDIO_XSMI_POLL_INTERVAL_MIN,
204 .poll_interval_max = MVMDIO_XSMI_POLL_INTERVAL_MAX,
205 };
206
orion_mdio_xsmi_read(struct mii_bus * bus,int mii_id,int regnum)207 static int orion_mdio_xsmi_read(struct mii_bus *bus, int mii_id,
208 int regnum)
209 {
210 struct orion_mdio_dev *dev = bus->priv;
211 u16 dev_addr = (regnum >> 16) & GENMASK(4, 0);
212 int ret;
213
214 if (!(regnum & MII_ADDR_C45))
215 return -EOPNOTSUPP;
216
217 ret = orion_mdio_wait_ready(&orion_mdio_xsmi_ops, bus);
218 if (ret < 0)
219 return ret;
220
221 writel(regnum & GENMASK(15, 0), dev->regs + MVMDIO_XSMI_ADDR_REG);
222 writel((mii_id << MVMDIO_XSMI_PHYADDR_SHIFT) |
223 (dev_addr << MVMDIO_XSMI_DEVADDR_SHIFT) |
224 MVMDIO_XSMI_READ_OPERATION,
225 dev->regs + MVMDIO_XSMI_MGNT_REG);
226
227 ret = orion_mdio_wait_ready(&orion_mdio_xsmi_ops, bus);
228 if (ret < 0)
229 return ret;
230
231 if (!(readl(dev->regs + MVMDIO_XSMI_MGNT_REG) &
232 MVMDIO_XSMI_READ_VALID)) {
233 dev_err(bus->parent, "XSMI bus read not valid\n");
234 return -ENODEV;
235 }
236
237 return readl(dev->regs + MVMDIO_XSMI_MGNT_REG) & GENMASK(15, 0);
238 }
239
orion_mdio_xsmi_write(struct mii_bus * bus,int mii_id,int regnum,u16 value)240 static int orion_mdio_xsmi_write(struct mii_bus *bus, int mii_id,
241 int regnum, u16 value)
242 {
243 struct orion_mdio_dev *dev = bus->priv;
244 u16 dev_addr = (regnum >> 16) & GENMASK(4, 0);
245 int ret;
246
247 if (!(regnum & MII_ADDR_C45))
248 return -EOPNOTSUPP;
249
250 ret = orion_mdio_wait_ready(&orion_mdio_xsmi_ops, bus);
251 if (ret < 0)
252 return ret;
253
254 writel(regnum & GENMASK(15, 0), dev->regs + MVMDIO_XSMI_ADDR_REG);
255 writel((mii_id << MVMDIO_XSMI_PHYADDR_SHIFT) |
256 (dev_addr << MVMDIO_XSMI_DEVADDR_SHIFT) |
257 MVMDIO_XSMI_WRITE_OPERATION | value,
258 dev->regs + MVMDIO_XSMI_MGNT_REG);
259
260 return 0;
261 }
262
orion_mdio_err_irq(int irq,void * dev_id)263 static irqreturn_t orion_mdio_err_irq(int irq, void *dev_id)
264 {
265 struct orion_mdio_dev *dev = dev_id;
266
267 if (readl(dev->regs + MVMDIO_ERR_INT_CAUSE) &
268 MVMDIO_ERR_INT_SMI_DONE) {
269 writel(~MVMDIO_ERR_INT_SMI_DONE,
270 dev->regs + MVMDIO_ERR_INT_CAUSE);
271 wake_up(&dev->smi_busy_wait);
272 return IRQ_HANDLED;
273 }
274
275 return IRQ_NONE;
276 }
277
orion_mdio_probe(struct platform_device * pdev)278 static int orion_mdio_probe(struct platform_device *pdev)
279 {
280 enum orion_mdio_bus_type type;
281 struct resource *r;
282 struct mii_bus *bus;
283 struct orion_mdio_dev *dev;
284 int i, ret;
285
286 type = (enum orion_mdio_bus_type)device_get_match_data(&pdev->dev);
287
288 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
289 if (!r) {
290 dev_err(&pdev->dev, "No SMI register address given\n");
291 return -ENODEV;
292 }
293
294 bus = devm_mdiobus_alloc_size(&pdev->dev,
295 sizeof(struct orion_mdio_dev));
296 if (!bus)
297 return -ENOMEM;
298
299 switch (type) {
300 case BUS_TYPE_SMI:
301 bus->read = orion_mdio_smi_read;
302 bus->write = orion_mdio_smi_write;
303 break;
304 case BUS_TYPE_XSMI:
305 bus->read = orion_mdio_xsmi_read;
306 bus->write = orion_mdio_xsmi_write;
307 break;
308 }
309
310 bus->name = "orion_mdio_bus";
311 snprintf(bus->id, MII_BUS_ID_SIZE, "%s-mii",
312 dev_name(&pdev->dev));
313 bus->parent = &pdev->dev;
314
315 dev = bus->priv;
316 dev->regs = devm_ioremap(&pdev->dev, r->start, resource_size(r));
317 if (!dev->regs) {
318 dev_err(&pdev->dev, "Unable to remap SMI register\n");
319 return -ENODEV;
320 }
321
322 init_waitqueue_head(&dev->smi_busy_wait);
323
324 if (pdev->dev.of_node) {
325 for (i = 0; i < ARRAY_SIZE(dev->clk); i++) {
326 dev->clk[i] = of_clk_get(pdev->dev.of_node, i);
327 if (PTR_ERR(dev->clk[i]) == -EPROBE_DEFER) {
328 ret = -EPROBE_DEFER;
329 goto out_clk;
330 }
331 if (IS_ERR(dev->clk[i]))
332 break;
333 clk_prepare_enable(dev->clk[i]);
334 }
335
336 if (!IS_ERR(of_clk_get(pdev->dev.of_node,
337 ARRAY_SIZE(dev->clk))))
338 dev_warn(&pdev->dev,
339 "unsupported number of clocks, limiting to the first "
340 __stringify(ARRAY_SIZE(dev->clk)) "\n");
341 } else {
342 dev->clk[0] = clk_get(&pdev->dev, NULL);
343 if (PTR_ERR(dev->clk[0]) == -EPROBE_DEFER) {
344 ret = -EPROBE_DEFER;
345 goto out_clk;
346 }
347 if (!IS_ERR(dev->clk[0]))
348 clk_prepare_enable(dev->clk[0]);
349 }
350
351
352 dev->err_interrupt = platform_get_irq_optional(pdev, 0);
353 if (dev->err_interrupt > 0 &&
354 resource_size(r) < MVMDIO_ERR_INT_MASK + 4) {
355 dev_err(&pdev->dev,
356 "disabling interrupt, resource size is too small\n");
357 dev->err_interrupt = 0;
358 }
359 if (dev->err_interrupt > 0) {
360 ret = devm_request_irq(&pdev->dev, dev->err_interrupt,
361 orion_mdio_err_irq,
362 IRQF_SHARED, pdev->name, dev);
363 if (ret)
364 goto out_mdio;
365
366 writel(MVMDIO_ERR_INT_SMI_DONE,
367 dev->regs + MVMDIO_ERR_INT_MASK);
368
369 } else if (dev->err_interrupt == -EPROBE_DEFER) {
370 ret = -EPROBE_DEFER;
371 goto out_mdio;
372 }
373
374 /* For the platforms not supporting DT/ACPI fall-back
375 * to mdiobus_register via of_mdiobus_register.
376 */
377 if (is_acpi_node(pdev->dev.fwnode))
378 ret = acpi_mdiobus_register(bus, pdev->dev.fwnode);
379 else
380 ret = of_mdiobus_register(bus, pdev->dev.of_node);
381 if (ret < 0) {
382 dev_err(&pdev->dev, "Cannot register MDIO bus (%d)\n", ret);
383 goto out_mdio;
384 }
385
386 platform_set_drvdata(pdev, bus);
387
388 return 0;
389
390 out_mdio:
391 if (dev->err_interrupt > 0)
392 writel(0, dev->regs + MVMDIO_ERR_INT_MASK);
393
394 out_clk:
395 for (i = 0; i < ARRAY_SIZE(dev->clk); i++) {
396 if (IS_ERR(dev->clk[i]))
397 break;
398 clk_disable_unprepare(dev->clk[i]);
399 clk_put(dev->clk[i]);
400 }
401
402 return ret;
403 }
404
orion_mdio_remove(struct platform_device * pdev)405 static int orion_mdio_remove(struct platform_device *pdev)
406 {
407 struct mii_bus *bus = platform_get_drvdata(pdev);
408 struct orion_mdio_dev *dev = bus->priv;
409 int i;
410
411 if (dev->err_interrupt > 0)
412 writel(0, dev->regs + MVMDIO_ERR_INT_MASK);
413 mdiobus_unregister(bus);
414
415 for (i = 0; i < ARRAY_SIZE(dev->clk); i++) {
416 if (IS_ERR(dev->clk[i]))
417 break;
418 clk_disable_unprepare(dev->clk[i]);
419 clk_put(dev->clk[i]);
420 }
421
422 return 0;
423 }
424
425 static const struct of_device_id orion_mdio_match[] = {
426 { .compatible = "marvell,orion-mdio", .data = (void *)BUS_TYPE_SMI },
427 { .compatible = "marvell,xmdio", .data = (void *)BUS_TYPE_XSMI },
428 { }
429 };
430 MODULE_DEVICE_TABLE(of, orion_mdio_match);
431
432 #ifdef CONFIG_ACPI
433 static const struct acpi_device_id orion_mdio_acpi_match[] = {
434 { "MRVL0100", BUS_TYPE_SMI },
435 { "MRVL0101", BUS_TYPE_XSMI },
436 { },
437 };
438 MODULE_DEVICE_TABLE(acpi, orion_mdio_acpi_match);
439 #endif
440
441 static struct platform_driver orion_mdio_driver = {
442 .probe = orion_mdio_probe,
443 .remove = orion_mdio_remove,
444 .driver = {
445 .name = "orion-mdio",
446 .of_match_table = orion_mdio_match,
447 .acpi_match_table = ACPI_PTR(orion_mdio_acpi_match),
448 },
449 };
450
451 module_platform_driver(orion_mdio_driver);
452
453 MODULE_DESCRIPTION("Marvell MDIO interface driver");
454 MODULE_AUTHOR("Thomas Petazzoni <thomas.petazzoni@free-electrons.com>");
455 MODULE_LICENSE("GPL");
456 MODULE_ALIAS("platform:orion-mdio");
457