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/iopoll.h>
27#include <linux/kernel.h>
28#include <linux/mod_devicetable.h>
29#include <linux/module.h>
30#include <linux/of_mdio.h>
31#include <linux/phy.h>
32#include <linux/platform_device.h>
33#include <linux/sched.h>
34#include <linux/wait.h>
35
36#define MVMDIO_SMI_DATA_SHIFT 0
37#define MVMDIO_SMI_PHY_ADDR_SHIFT 16
38#define MVMDIO_SMI_PHY_REG_SHIFT 21
39#define MVMDIO_SMI_READ_OPERATION BIT(26)
40#define MVMDIO_SMI_WRITE_OPERATION 0
41#define MVMDIO_SMI_READ_VALID BIT(27)
42#define MVMDIO_SMI_BUSY BIT(28)
43#define MVMDIO_ERR_INT_CAUSE 0x007C
44#define MVMDIO_ERR_INT_SMI_DONE 0x00000010
45#define MVMDIO_ERR_INT_MASK 0x0080
46
47#define MVMDIO_XSMI_MGNT_REG 0x0
48#define MVMDIO_XSMI_PHYADDR_SHIFT 16
49#define MVMDIO_XSMI_DEVADDR_SHIFT 21
50#define MVMDIO_XSMI_WRITE_OPERATION (0x5 << 26)
51#define MVMDIO_XSMI_READ_OPERATION (0x7 << 26)
52#define MVMDIO_XSMI_READ_VALID BIT(29)
53#define MVMDIO_XSMI_BUSY BIT(30)
54#define MVMDIO_XSMI_ADDR_REG 0x8
55
56#define MVMDIO_XSMI_CFG_REG 0xc
57#define MVMDIO_XSMI_CLKDIV_MASK 0x3
58#define MVMDIO_XSMI_CLKDIV_256 0x0
59#define MVMDIO_XSMI_CLKDIV_64 0x1
60#define MVMDIO_XSMI_CLKDIV_32 0x2
61#define MVMDIO_XSMI_CLKDIV_8 0x3
62
63/*
64 * SMI Timeout measurements:
65 * - Kirkwood 88F6281 (Globalscale Dreamplug): 45us to 95us (Interrupt)
66 * - Armada 370 (Globalscale Mirabox): 41us to 43us (Polled)
67 */
68#define MVMDIO_SMI_TIMEOUT 1000 /* 1000us = 1ms */
69
70struct orion_mdio_dev {
71 void __iomem *regs;
72 struct clk *clk[4];
73 /*
74 * If we have access to the error interrupt pin (which is
75 * somewhat misnamed as it not only reflects internal errors
76 * but also reflects SMI completion), use that to wait for
77 * SMI access completion instead of polling the SMI busy bit.
78 */
79 int err_interrupt;
80 wait_queue_head_t smi_busy_wait;
81};
82
83enum orion_mdio_bus_type {
84 BUS_TYPE_SMI,
85 BUS_TYPE_XSMI
86};
87
88struct orion_mdio_ops {
89 int (*is_done)(struct orion_mdio_dev *);
90};
91
92/* Wait for the SMI unit to be ready for another operation
93 */
94static int orion_mdio_wait_ready(const struct orion_mdio_ops *ops,
95 struct mii_bus *bus)
96{
97 struct orion_mdio_dev *dev = bus->priv;
98 unsigned long timeout;
99 int done;
100
101 if (dev->err_interrupt <= 0) {
102 if (!read_poll_timeout_atomic(ops->is_done, done, done, 2,
103 MVMDIO_SMI_TIMEOUT, false, dev))
104 return 0;
105 } else {
106 /* wait_event_timeout does not guarantee a delay of at
107 * least one whole jiffie, so timeout must be no less
108 * than two.
109 */
110 timeout = max(usecs_to_jiffies(MVMDIO_SMI_TIMEOUT), 2);
111
112 if (wait_event_timeout(dev->smi_busy_wait,
113 ops->is_done(dev), timeout))
114 return 0;
115 }
116
117 dev_err(bus->parent, "Timeout: SMI busy for too long\n");
118 return -ETIMEDOUT;
119}
120
121static int orion_mdio_smi_is_done(struct orion_mdio_dev *dev)
122{
123 return !(readl(addr: dev->regs) & MVMDIO_SMI_BUSY);
124}
125
126static const struct orion_mdio_ops orion_mdio_smi_ops = {
127 .is_done = orion_mdio_smi_is_done,
128};
129
130static int orion_mdio_smi_read(struct mii_bus *bus, int mii_id,
131 int regnum)
132{
133 struct orion_mdio_dev *dev = bus->priv;
134 u32 val;
135 int ret;
136
137 ret = orion_mdio_wait_ready(ops: &orion_mdio_smi_ops, bus);
138 if (ret < 0)
139 return ret;
140
141 writel(val: ((mii_id << MVMDIO_SMI_PHY_ADDR_SHIFT) |
142 (regnum << MVMDIO_SMI_PHY_REG_SHIFT) |
143 MVMDIO_SMI_READ_OPERATION),
144 addr: dev->regs);
145
146 ret = orion_mdio_wait_ready(ops: &orion_mdio_smi_ops, bus);
147 if (ret < 0)
148 return ret;
149
150 val = readl(addr: dev->regs);
151 if (!(val & MVMDIO_SMI_READ_VALID)) {
152 dev_err(bus->parent, "SMI bus read not valid\n");
153 return -ENODEV;
154 }
155
156 return val & GENMASK(15, 0);
157}
158
159static int orion_mdio_smi_write(struct mii_bus *bus, int mii_id,
160 int regnum, u16 value)
161{
162 struct orion_mdio_dev *dev = bus->priv;
163 int ret;
164
165 ret = orion_mdio_wait_ready(ops: &orion_mdio_smi_ops, bus);
166 if (ret < 0)
167 return ret;
168
169 writel(val: ((mii_id << MVMDIO_SMI_PHY_ADDR_SHIFT) |
170 (regnum << MVMDIO_SMI_PHY_REG_SHIFT) |
171 MVMDIO_SMI_WRITE_OPERATION |
172 (value << MVMDIO_SMI_DATA_SHIFT)),
173 addr: dev->regs);
174
175 return 0;
176}
177
178static int orion_mdio_xsmi_is_done(struct orion_mdio_dev *dev)
179{
180 return !(readl(addr: dev->regs + MVMDIO_XSMI_MGNT_REG) & MVMDIO_XSMI_BUSY);
181}
182
183static const struct orion_mdio_ops orion_mdio_xsmi_ops = {
184 .is_done = orion_mdio_xsmi_is_done,
185};
186
187static int orion_mdio_xsmi_read_c45(struct mii_bus *bus, int mii_id,
188 int dev_addr, int regnum)
189{
190 struct orion_mdio_dev *dev = bus->priv;
191 int ret;
192
193 ret = orion_mdio_wait_ready(ops: &orion_mdio_xsmi_ops, bus);
194 if (ret < 0)
195 return ret;
196
197 writel(val: regnum, addr: dev->regs + MVMDIO_XSMI_ADDR_REG);
198 writel(val: (mii_id << MVMDIO_XSMI_PHYADDR_SHIFT) |
199 (dev_addr << MVMDIO_XSMI_DEVADDR_SHIFT) |
200 MVMDIO_XSMI_READ_OPERATION,
201 addr: dev->regs + MVMDIO_XSMI_MGNT_REG);
202
203 ret = orion_mdio_wait_ready(ops: &orion_mdio_xsmi_ops, bus);
204 if (ret < 0)
205 return ret;
206
207 if (!(readl(addr: dev->regs + MVMDIO_XSMI_MGNT_REG) &
208 MVMDIO_XSMI_READ_VALID)) {
209 dev_err(bus->parent, "XSMI bus read not valid\n");
210 return -ENODEV;
211 }
212
213 return readl(addr: dev->regs + MVMDIO_XSMI_MGNT_REG) & GENMASK(15, 0);
214}
215
216static int orion_mdio_xsmi_write_c45(struct mii_bus *bus, int mii_id,
217 int dev_addr, int regnum, u16 value)
218{
219 struct orion_mdio_dev *dev = bus->priv;
220 int ret;
221
222 ret = orion_mdio_wait_ready(ops: &orion_mdio_xsmi_ops, bus);
223 if (ret < 0)
224 return ret;
225
226 writel(val: regnum, addr: dev->regs + MVMDIO_XSMI_ADDR_REG);
227 writel(val: (mii_id << MVMDIO_XSMI_PHYADDR_SHIFT) |
228 (dev_addr << MVMDIO_XSMI_DEVADDR_SHIFT) |
229 MVMDIO_XSMI_WRITE_OPERATION | value,
230 addr: dev->regs + MVMDIO_XSMI_MGNT_REG);
231
232 return 0;
233}
234
235static void orion_mdio_xsmi_set_mdc_freq(struct mii_bus *bus)
236{
237 struct orion_mdio_dev *dev = bus->priv;
238 struct clk *mg_core;
239 u32 div, freq, cfg;
240
241 if (device_property_read_u32(dev: bus->parent, propname: "clock-frequency", val: &freq))
242 return;
243
244 mg_core = of_clk_get_by_name(np: bus->parent->of_node, name: "mg_core_clk");
245 if (IS_ERR(ptr: mg_core)) {
246 dev_err(bus->parent,
247 "MG core clock unknown, not changing MDC frequency");
248 return;
249 }
250
251 div = clk_get_rate(clk: mg_core) / (freq + 1) + 1;
252 clk_put(clk: mg_core);
253
254 if (div <= 8)
255 div = MVMDIO_XSMI_CLKDIV_8;
256 else if (div <= 32)
257 div = MVMDIO_XSMI_CLKDIV_32;
258 else if (div <= 64)
259 div = MVMDIO_XSMI_CLKDIV_64;
260 else
261 div = MVMDIO_XSMI_CLKDIV_256;
262
263 cfg = readl(addr: dev->regs + MVMDIO_XSMI_CFG_REG);
264 cfg &= ~MVMDIO_XSMI_CLKDIV_MASK;
265 cfg |= div;
266 writel(val: cfg, addr: dev->regs + MVMDIO_XSMI_CFG_REG);
267}
268
269static irqreturn_t orion_mdio_err_irq(int irq, void *dev_id)
270{
271 struct orion_mdio_dev *dev = dev_id;
272
273 if (readl(addr: dev->regs + MVMDIO_ERR_INT_CAUSE) &
274 MVMDIO_ERR_INT_SMI_DONE) {
275 writel(val: ~MVMDIO_ERR_INT_SMI_DONE,
276 addr: dev->regs + MVMDIO_ERR_INT_CAUSE);
277 wake_up(&dev->smi_busy_wait);
278 return IRQ_HANDLED;
279 }
280
281 return IRQ_NONE;
282}
283
284static int orion_mdio_probe(struct platform_device *pdev)
285{
286 enum orion_mdio_bus_type type;
287 struct resource *r;
288 struct mii_bus *bus;
289 struct orion_mdio_dev *dev;
290 int i, ret;
291
292 type = (uintptr_t)device_get_match_data(dev: &pdev->dev);
293
294 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
295 if (!r) {
296 dev_err(&pdev->dev, "No SMI register address given\n");
297 return -ENODEV;
298 }
299
300 bus = devm_mdiobus_alloc_size(dev: &pdev->dev,
301 sizeof_priv: sizeof(struct orion_mdio_dev));
302 if (!bus)
303 return -ENOMEM;
304
305 switch (type) {
306 case BUS_TYPE_SMI:
307 bus->read = orion_mdio_smi_read;
308 bus->write = orion_mdio_smi_write;
309 break;
310 case BUS_TYPE_XSMI:
311 bus->read_c45 = orion_mdio_xsmi_read_c45;
312 bus->write_c45 = orion_mdio_xsmi_write_c45;
313 break;
314 }
315
316 bus->name = "orion_mdio_bus";
317 snprintf(buf: bus->id, MII_BUS_ID_SIZE, fmt: "%s-mii",
318 dev_name(dev: &pdev->dev));
319 bus->parent = &pdev->dev;
320
321 dev = bus->priv;
322 dev->regs = devm_ioremap(dev: &pdev->dev, offset: r->start, size: resource_size(res: r));
323 if (!dev->regs) {
324 dev_err(&pdev->dev, "Unable to remap SMI register\n");
325 return -ENODEV;
326 }
327
328 init_waitqueue_head(&dev->smi_busy_wait);
329
330 if (pdev->dev.of_node) {
331 for (i = 0; i < ARRAY_SIZE(dev->clk); i++) {
332 dev->clk[i] = of_clk_get(np: pdev->dev.of_node, index: i);
333 if (PTR_ERR(ptr: dev->clk[i]) == -EPROBE_DEFER) {
334 ret = -EPROBE_DEFER;
335 goto out_clk;
336 }
337 if (IS_ERR(ptr: dev->clk[i]))
338 break;
339 clk_prepare_enable(clk: dev->clk[i]);
340 }
341
342 if (!IS_ERR(ptr: of_clk_get(np: pdev->dev.of_node,
343 ARRAY_SIZE(dev->clk))))
344 dev_warn(&pdev->dev,
345 "unsupported number of clocks, limiting to the first "
346 __stringify(ARRAY_SIZE(dev->clk)) "\n");
347
348 if (type == BUS_TYPE_XSMI)
349 orion_mdio_xsmi_set_mdc_freq(bus);
350 } else {
351 dev->clk[0] = clk_get(dev: &pdev->dev, NULL);
352 if (PTR_ERR(ptr: dev->clk[0]) == -EPROBE_DEFER) {
353 ret = -EPROBE_DEFER;
354 goto out_clk;
355 }
356 if (!IS_ERR(ptr: dev->clk[0]))
357 clk_prepare_enable(clk: dev->clk[0]);
358 }
359
360
361 dev->err_interrupt = platform_get_irq_optional(pdev, 0);
362 if (dev->err_interrupt > 0 &&
363 resource_size(res: r) < MVMDIO_ERR_INT_MASK + 4) {
364 dev_err(&pdev->dev,
365 "disabling interrupt, resource size is too small\n");
366 dev->err_interrupt = 0;
367 }
368 if (dev->err_interrupt > 0) {
369 ret = devm_request_irq(dev: &pdev->dev, irq: dev->err_interrupt,
370 handler: orion_mdio_err_irq,
371 IRQF_SHARED, devname: pdev->name, dev_id: dev);
372 if (ret)
373 goto out_mdio;
374
375 writel(MVMDIO_ERR_INT_SMI_DONE,
376 addr: dev->regs + MVMDIO_ERR_INT_MASK);
377
378 } else if (dev->err_interrupt == -EPROBE_DEFER) {
379 ret = -EPROBE_DEFER;
380 goto out_mdio;
381 }
382
383 /* For the platforms not supporting DT/ACPI fall-back
384 * to mdiobus_register via of_mdiobus_register.
385 */
386 if (is_acpi_node(fwnode: pdev->dev.fwnode))
387 ret = acpi_mdiobus_register(mdio: bus, handle: pdev->dev.fwnode);
388 else
389 ret = of_mdiobus_register(mdio: bus, np: pdev->dev.of_node);
390 if (ret < 0) {
391 dev_err(&pdev->dev, "Cannot register MDIO bus (%d)\n", ret);
392 goto out_mdio;
393 }
394
395 platform_set_drvdata(pdev, data: bus);
396
397 return 0;
398
399out_mdio:
400 if (dev->err_interrupt > 0)
401 writel(val: 0, addr: dev->regs + MVMDIO_ERR_INT_MASK);
402
403out_clk:
404 for (i = 0; i < ARRAY_SIZE(dev->clk); i++) {
405 if (IS_ERR(ptr: dev->clk[i]))
406 break;
407 clk_disable_unprepare(clk: dev->clk[i]);
408 clk_put(clk: dev->clk[i]);
409 }
410
411 return ret;
412}
413
414static void orion_mdio_remove(struct platform_device *pdev)
415{
416 struct mii_bus *bus = platform_get_drvdata(pdev);
417 struct orion_mdio_dev *dev = bus->priv;
418 int i;
419
420 if (dev->err_interrupt > 0)
421 writel(val: 0, addr: dev->regs + MVMDIO_ERR_INT_MASK);
422 mdiobus_unregister(bus);
423
424 for (i = 0; i < ARRAY_SIZE(dev->clk); i++) {
425 if (IS_ERR(ptr: dev->clk[i]))
426 break;
427 clk_disable_unprepare(clk: dev->clk[i]);
428 clk_put(clk: dev->clk[i]);
429 }
430}
431
432static const struct of_device_id orion_mdio_match[] = {
433 { .compatible = "marvell,orion-mdio", .data = (void *)BUS_TYPE_SMI },
434 { .compatible = "marvell,xmdio", .data = (void *)BUS_TYPE_XSMI },
435 { }
436};
437MODULE_DEVICE_TABLE(of, orion_mdio_match);
438
439#ifdef CONFIG_ACPI
440static const struct acpi_device_id orion_mdio_acpi_match[] = {
441 { "MRVL0100", BUS_TYPE_SMI },
442 { "MRVL0101", BUS_TYPE_XSMI },
443 { },
444};
445MODULE_DEVICE_TABLE(acpi, orion_mdio_acpi_match);
446#endif
447
448static struct platform_driver orion_mdio_driver = {
449 .probe = orion_mdio_probe,
450 .remove_new = orion_mdio_remove,
451 .driver = {
452 .name = "orion-mdio",
453 .of_match_table = orion_mdio_match,
454 .acpi_match_table = ACPI_PTR(orion_mdio_acpi_match),
455 },
456};
457
458module_platform_driver(orion_mdio_driver);
459
460MODULE_DESCRIPTION("Marvell MDIO interface driver");
461MODULE_AUTHOR("Thomas Petazzoni <thomas.petazzoni@free-electrons.com>");
462MODULE_LICENSE("GPL");
463MODULE_ALIAS("platform:orion-mdio");
464

source code of linux/drivers/net/ethernet/marvell/mvmdio.c