2 * Driver for the MDIO interface of Marvell network interfaces.
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
11 * Copyright (C) 2012 Marvell
13 * Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
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.
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>
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>
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
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
56 * SMI Timeout measurements:
57 * - Kirkwood 88F6281 (Globalscale Dreamplug): 45us to 95us (Interrupt)
58 * - Armada 370 (Globalscale Mirabox): 41us to 43us (Polled)
60 #define MVMDIO_SMI_TIMEOUT 1000 /* 1000us = 1ms */
61 #define MVMDIO_SMI_POLL_INTERVAL_MIN 45
62 #define MVMDIO_SMI_POLL_INTERVAL_MAX 55
64 #define MVMDIO_XSMI_POLL_INTERVAL_MIN 150
65 #define MVMDIO_XSMI_POLL_INTERVAL_MAX 160
67 struct orion_mdio_dev {
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.
77 wait_queue_head_t smi_busy_wait;
80 enum orion_mdio_bus_type {
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;
91 /* Wait for the SMI unit to be ready for another operation
93 static int orion_mdio_wait_ready(const struct orion_mdio_ops *ops,
96 struct orion_mdio_dev *dev = bus->priv;
97 unsigned long timeout = usecs_to_jiffies(MVMDIO_SMI_TIMEOUT);
98 unsigned long end = jiffies + timeout;
102 if (ops->is_done(dev))
107 if (dev->err_interrupt <= 0) {
108 usleep_range(ops->poll_interval_min,
109 ops->poll_interval_max);
111 if (time_is_before_jiffies(end))
114 /* wait_event_timeout does not guarantee a delay of at
115 * least one whole jiffie, so timeout must be no less
120 wait_event_timeout(dev->smi_busy_wait,
121 ops->is_done(dev), timeout);
127 dev_err(bus->parent, "Timeout: SMI busy for too long\n");
131 static int orion_mdio_smi_is_done(struct orion_mdio_dev *dev)
133 return !(readl(dev->regs) & MVMDIO_SMI_BUSY);
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,
142 static int orion_mdio_smi_read(struct mii_bus *bus, int mii_id,
145 struct orion_mdio_dev *dev = bus->priv;
149 if (regnum & MII_ADDR_C45)
152 ret = orion_mdio_wait_ready(&orion_mdio_smi_ops, bus);
156 writel(((mii_id << MVMDIO_SMI_PHY_ADDR_SHIFT) |
157 (regnum << MVMDIO_SMI_PHY_REG_SHIFT) |
158 MVMDIO_SMI_READ_OPERATION),
161 ret = orion_mdio_wait_ready(&orion_mdio_smi_ops, bus);
165 val = readl(dev->regs);
166 if (!(val & MVMDIO_SMI_READ_VALID)) {
167 dev_err(bus->parent, "SMI bus read not valid\n");
171 return val & GENMASK(15, 0);
174 static int orion_mdio_smi_write(struct mii_bus *bus, int mii_id,
175 int regnum, u16 value)
177 struct orion_mdio_dev *dev = bus->priv;
180 if (regnum & MII_ADDR_C45)
183 ret = orion_mdio_wait_ready(&orion_mdio_smi_ops, bus);
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)),
196 static int orion_mdio_xsmi_is_done(struct orion_mdio_dev *dev)
198 return !(readl(dev->regs + MVMDIO_XSMI_MGNT_REG) & MVMDIO_XSMI_BUSY);
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,
207 static int orion_mdio_xsmi_read(struct mii_bus *bus, int mii_id,
210 struct orion_mdio_dev *dev = bus->priv;
211 u16 dev_addr = (regnum >> 16) & GENMASK(4, 0);
214 if (!(regnum & MII_ADDR_C45))
217 ret = orion_mdio_wait_ready(&orion_mdio_xsmi_ops, bus);
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);
227 ret = orion_mdio_wait_ready(&orion_mdio_xsmi_ops, bus);
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");
237 return readl(dev->regs + MVMDIO_XSMI_MGNT_REG) & GENMASK(15, 0);
240 static int orion_mdio_xsmi_write(struct mii_bus *bus, int mii_id,
241 int regnum, u16 value)
243 struct orion_mdio_dev *dev = bus->priv;
244 u16 dev_addr = (regnum >> 16) & GENMASK(4, 0);
247 if (!(regnum & MII_ADDR_C45))
250 ret = orion_mdio_wait_ready(&orion_mdio_xsmi_ops, bus);
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);
263 static irqreturn_t orion_mdio_err_irq(int irq, void *dev_id)
265 struct orion_mdio_dev *dev = dev_id;
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);
278 static int orion_mdio_probe(struct platform_device *pdev)
280 enum orion_mdio_bus_type type;
283 struct orion_mdio_dev *dev;
286 type = (enum orion_mdio_bus_type)device_get_match_data(&pdev->dev);
288 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
290 dev_err(&pdev->dev, "No SMI register address given\n");
294 bus = devm_mdiobus_alloc_size(&pdev->dev,
295 sizeof(struct orion_mdio_dev));
301 bus->read = orion_mdio_smi_read;
302 bus->write = orion_mdio_smi_write;
305 bus->read = orion_mdio_xsmi_read;
306 bus->write = orion_mdio_xsmi_write;
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;
316 dev->regs = devm_ioremap(&pdev->dev, r->start, resource_size(r));
318 dev_err(&pdev->dev, "Unable to remap SMI register\n");
322 init_waitqueue_head(&dev->smi_busy_wait);
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) {
331 if (IS_ERR(dev->clk[i]))
333 clk_prepare_enable(dev->clk[i]);
336 if (!IS_ERR(of_clk_get(pdev->dev.of_node,
337 ARRAY_SIZE(dev->clk))))
339 "unsupported number of clocks, limiting to the first "
340 __stringify(ARRAY_SIZE(dev->clk)) "\n");
342 dev->clk[0] = clk_get(&pdev->dev, NULL);
343 if (PTR_ERR(dev->clk[0]) == -EPROBE_DEFER) {
347 if (!IS_ERR(dev->clk[0]))
348 clk_prepare_enable(dev->clk[0]);
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) {
356 "disabling interrupt, resource size is too small\n");
357 dev->err_interrupt = 0;
359 if (dev->err_interrupt > 0) {
360 ret = devm_request_irq(&pdev->dev, dev->err_interrupt,
362 IRQF_SHARED, pdev->name, dev);
366 writel(MVMDIO_ERR_INT_SMI_DONE,
367 dev->regs + MVMDIO_ERR_INT_MASK);
369 } else if (dev->err_interrupt == -EPROBE_DEFER) {
374 /* For the platforms not supporting DT/ACPI fall-back
375 * to mdiobus_register via of_mdiobus_register.
377 if (is_acpi_node(pdev->dev.fwnode))
378 ret = acpi_mdiobus_register(bus, pdev->dev.fwnode);
380 ret = of_mdiobus_register(bus, pdev->dev.of_node);
382 dev_err(&pdev->dev, "Cannot register MDIO bus (%d)\n", ret);
386 platform_set_drvdata(pdev, bus);
391 if (dev->err_interrupt > 0)
392 writel(0, dev->regs + MVMDIO_ERR_INT_MASK);
395 for (i = 0; i < ARRAY_SIZE(dev->clk); i++) {
396 if (IS_ERR(dev->clk[i]))
398 clk_disable_unprepare(dev->clk[i]);
399 clk_put(dev->clk[i]);
405 static int orion_mdio_remove(struct platform_device *pdev)
407 struct mii_bus *bus = platform_get_drvdata(pdev);
408 struct orion_mdio_dev *dev = bus->priv;
411 if (dev->err_interrupt > 0)
412 writel(0, dev->regs + MVMDIO_ERR_INT_MASK);
413 mdiobus_unregister(bus);
415 for (i = 0; i < ARRAY_SIZE(dev->clk); i++) {
416 if (IS_ERR(dev->clk[i]))
418 clk_disable_unprepare(dev->clk[i]);
419 clk_put(dev->clk[i]);
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 },
430 MODULE_DEVICE_TABLE(of, orion_mdio_match);
433 static const struct acpi_device_id orion_mdio_acpi_match[] = {
434 { "MRVL0100", BUS_TYPE_SMI },
435 { "MRVL0101", BUS_TYPE_XSMI },
438 MODULE_DEVICE_TABLE(acpi, orion_mdio_acpi_match);
441 static struct platform_driver orion_mdio_driver = {
442 .probe = orion_mdio_probe,
443 .remove = orion_mdio_remove,
445 .name = "orion-mdio",
446 .of_match_table = orion_mdio_match,
447 .acpi_match_table = ACPI_PTR(orion_mdio_acpi_match),
451 module_platform_driver(orion_mdio_driver);
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");