2 * DaVinci MDIO Module driver
4 * Copyright (C) 2010 Texas Instruments.
6 * Shamelessly ripped out of davinci_emac.c, original copyrights follow:
8 * Copyright (C) 2009 Texas Instruments.
10 * ---------------------------------------------------------------------------
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License as published by
14 * the Free Software Foundation; either version 2 of the License, or
15 * (at your option) any later version.
17 * This program is distributed in the hope that it will be useful,
18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 * GNU General Public License for more details.
22 * You should have received a copy of the GNU General Public License
23 * along with this program; if not, write to the Free Software
24 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
25 * ---------------------------------------------------------------------------
27 #include <linux/module.h>
28 #include <linux/kernel.h>
29 #include <linux/platform_device.h>
30 #include <linux/delay.h>
31 #include <linux/sched.h>
32 #include <linux/slab.h>
33 #include <linux/phy.h>
34 #include <linux/clk.h>
35 #include <linux/err.h>
37 #include <linux/pm_runtime.h>
38 #include <linux/davinci_emac.h>
40 #include <linux/of_device.h>
43 * This timeout definition is a worst-case ultra defensive measure against
44 * unexpected controller lock ups. Ideally, we should never ever hit this
45 * scenario in practice.
47 #define MDIO_TIMEOUT 100 /* msecs */
49 #define PHY_REG_MASK 0x1f
50 #define PHY_ID_MASK 0x1f
52 #define DEF_OUT_FREQ 2200000 /* 2.2 MHz */
54 struct davinci_mdio_regs {
57 #define CONTROL_IDLE BIT(31)
58 #define CONTROL_ENABLE BIT(30)
59 #define CONTROL_MAX_DIV (0xffff)
74 #define USERACCESS_GO BIT(31)
75 #define USERACCESS_WRITE BIT(30)
76 #define USERACCESS_ACK BIT(29)
77 #define USERACCESS_READ (0)
78 #define USERACCESS_DATA (0xffff)
84 struct mdio_platform_data default_pdata = {
85 .bus_freq = DEF_OUT_FREQ,
88 struct davinci_mdio_data {
89 struct mdio_platform_data pdata;
90 struct davinci_mdio_regs __iomem *regs;
96 unsigned long access_time; /* jiffies */
99 static void __davinci_mdio_reset(struct davinci_mdio_data *data)
101 u32 mdio_in, div, mdio_out_khz, access_time;
103 mdio_in = clk_get_rate(data->clk);
104 div = (mdio_in / data->pdata.bus_freq) - 1;
105 if (div > CONTROL_MAX_DIV)
106 div = CONTROL_MAX_DIV;
108 /* set enable and clock divider */
109 __raw_writel(div | CONTROL_ENABLE, &data->regs->control);
112 * One mdio transaction consists of:
113 * 32 bits of preamble
114 * 32 bits of transferred data
115 * 24 bits of bus yield (not needed unless shared?)
117 mdio_out_khz = mdio_in / (1000 * (div + 1));
118 access_time = (88 * 1000) / mdio_out_khz;
121 * In the worst case, we could be kicking off a user-access immediately
122 * after the mdio bus scan state-machine triggered its own read. If
123 * so, our request could get deferred by one access cycle. We
124 * defensively allow for 4 access cycles.
126 data->access_time = usecs_to_jiffies(access_time * 4);
127 if (!data->access_time)
128 data->access_time = 1;
131 static int davinci_mdio_reset(struct mii_bus *bus)
133 struct davinci_mdio_data *data = bus->priv;
136 __davinci_mdio_reset(data);
138 /* wait for scan logic to settle */
139 msleep(PHY_MAX_ADDR * data->access_time);
141 /* dump hardware version info */
142 ver = __raw_readl(&data->regs->version);
143 dev_info(data->dev, "davinci mdio revision %d.%d\n",
144 (ver >> 8) & 0xff, ver & 0xff);
146 /* get phy mask from the alive register */
147 phy_mask = __raw_readl(&data->regs->alive);
149 /* restrict mdio bus to live phys only */
150 dev_info(data->dev, "detected phy mask %x\n", ~phy_mask);
151 phy_mask = ~phy_mask;
153 /* desperately scan all phys */
154 dev_warn(data->dev, "no live phy, scanning all\n");
157 data->bus->phy_mask = phy_mask;
162 /* wait until hardware is ready for another user access */
163 static inline int wait_for_user_access(struct davinci_mdio_data *data)
165 struct davinci_mdio_regs __iomem *regs = data->regs;
166 unsigned long timeout = jiffies + msecs_to_jiffies(MDIO_TIMEOUT);
169 while (time_after(timeout, jiffies)) {
170 reg = __raw_readl(®s->user[0].access);
171 if ((reg & USERACCESS_GO) == 0)
174 reg = __raw_readl(®s->control);
175 if ((reg & CONTROL_IDLE) == 0)
179 * An emac soft_reset may have clobbered the mdio controller's
180 * state machine. We need to reset and retry the current
183 dev_warn(data->dev, "resetting idled controller\n");
184 __davinci_mdio_reset(data);
188 reg = __raw_readl(®s->user[0].access);
189 if ((reg & USERACCESS_GO) == 0)
192 dev_err(data->dev, "timed out waiting for user access\n");
196 /* wait until hardware state machine is idle */
197 static inline int wait_for_idle(struct davinci_mdio_data *data)
199 struct davinci_mdio_regs __iomem *regs = data->regs;
200 unsigned long timeout = jiffies + msecs_to_jiffies(MDIO_TIMEOUT);
202 while (time_after(timeout, jiffies)) {
203 if (__raw_readl(®s->control) & CONTROL_IDLE)
206 dev_err(data->dev, "timed out waiting for idle\n");
210 static int davinci_mdio_read(struct mii_bus *bus, int phy_id, int phy_reg)
212 struct davinci_mdio_data *data = bus->priv;
216 if (phy_reg & ~PHY_REG_MASK || phy_id & ~PHY_ID_MASK)
219 spin_lock(&data->lock);
221 if (data->suspended) {
222 spin_unlock(&data->lock);
226 reg = (USERACCESS_GO | USERACCESS_READ | (phy_reg << 21) |
230 ret = wait_for_user_access(data);
236 __raw_writel(reg, &data->regs->user[0].access);
238 ret = wait_for_user_access(data);
244 reg = __raw_readl(&data->regs->user[0].access);
245 ret = (reg & USERACCESS_ACK) ? (reg & USERACCESS_DATA) : -EIO;
249 spin_unlock(&data->lock);
254 static int davinci_mdio_write(struct mii_bus *bus, int phy_id,
255 int phy_reg, u16 phy_data)
257 struct davinci_mdio_data *data = bus->priv;
261 if (phy_reg & ~PHY_REG_MASK || phy_id & ~PHY_ID_MASK)
264 spin_lock(&data->lock);
266 if (data->suspended) {
267 spin_unlock(&data->lock);
271 reg = (USERACCESS_GO | USERACCESS_WRITE | (phy_reg << 21) |
272 (phy_id << 16) | (phy_data & USERACCESS_DATA));
275 ret = wait_for_user_access(data);
281 __raw_writel(reg, &data->regs->user[0].access);
283 ret = wait_for_user_access(data);
289 spin_unlock(&data->lock);
294 static int davinci_mdio_probe_dt(struct mdio_platform_data *data,
295 struct platform_device *pdev)
297 struct device_node *node = pdev->dev.of_node;
303 if (of_property_read_u32(node, "bus_freq", &prop)) {
304 pr_err("Missing bus_freq property in the DT.\n");
307 data->bus_freq = prop;
313 static int davinci_mdio_probe(struct platform_device *pdev)
315 struct mdio_platform_data *pdata = pdev->dev.platform_data;
316 struct device *dev = &pdev->dev;
317 struct davinci_mdio_data *data;
318 struct resource *res;
319 struct phy_device *phy;
322 data = kzalloc(sizeof(*data), GFP_KERNEL);
326 data->bus = mdiobus_alloc();
328 dev_err(dev, "failed to alloc mii bus\n");
334 if (davinci_mdio_probe_dt(&data->pdata, pdev))
335 data->pdata = default_pdata;
336 snprintf(data->bus->id, MII_BUS_ID_SIZE, "%s", pdev->name);
338 data->pdata = pdata ? (*pdata) : default_pdata;
339 snprintf(data->bus->id, MII_BUS_ID_SIZE, "%s-%x",
340 pdev->name, pdev->id);
343 data->bus->name = dev_name(dev);
344 data->bus->read = davinci_mdio_read,
345 data->bus->write = davinci_mdio_write,
346 data->bus->reset = davinci_mdio_reset,
347 data->bus->parent = dev;
348 data->bus->priv = data;
350 pm_runtime_enable(&pdev->dev);
351 pm_runtime_get_sync(&pdev->dev);
352 data->clk = clk_get(&pdev->dev, "fck");
353 if (IS_ERR(data->clk)) {
354 dev_err(dev, "failed to get device clock\n");
355 ret = PTR_ERR(data->clk);
360 dev_set_drvdata(dev, data);
362 spin_lock_init(&data->lock);
364 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
366 dev_err(dev, "could not find register map resource\n");
371 res = devm_request_mem_region(dev, res->start, resource_size(res),
374 dev_err(dev, "could not allocate register map resource\n");
379 data->regs = devm_ioremap_nocache(dev, res->start, resource_size(res));
381 dev_err(dev, "could not map mdio registers\n");
386 /* register the mii bus */
387 ret = mdiobus_register(data->bus);
391 /* scan and dump the bus */
392 for (addr = 0; addr < PHY_MAX_ADDR; addr++) {
393 phy = data->bus->phy_map[addr];
395 dev_info(dev, "phy[%d]: device %s, driver %s\n",
396 phy->addr, dev_name(&phy->dev),
397 phy->drv ? phy->drv->name : "unknown");
405 mdiobus_free(data->bus);
409 pm_runtime_put_sync(&pdev->dev);
410 pm_runtime_disable(&pdev->dev);
417 static int davinci_mdio_remove(struct platform_device *pdev)
419 struct device *dev = &pdev->dev;
420 struct davinci_mdio_data *data = dev_get_drvdata(dev);
423 mdiobus_unregister(data->bus);
424 mdiobus_free(data->bus);
429 pm_runtime_put_sync(&pdev->dev);
430 pm_runtime_disable(&pdev->dev);
432 dev_set_drvdata(dev, NULL);
439 static int davinci_mdio_suspend(struct device *dev)
441 struct davinci_mdio_data *data = dev_get_drvdata(dev);
444 spin_lock(&data->lock);
446 /* shutdown the scan state machine */
447 ctrl = __raw_readl(&data->regs->control);
448 ctrl &= ~CONTROL_ENABLE;
449 __raw_writel(ctrl, &data->regs->control);
452 data->suspended = true;
453 spin_unlock(&data->lock);
454 pm_runtime_put_sync(data->dev);
459 static int davinci_mdio_resume(struct device *dev)
461 struct davinci_mdio_data *data = dev_get_drvdata(dev);
463 pm_runtime_get_sync(data->dev);
465 spin_lock(&data->lock);
466 /* restart the scan state machine */
467 __davinci_mdio_reset(data);
469 data->suspended = false;
470 spin_unlock(&data->lock);
475 static const struct dev_pm_ops davinci_mdio_pm_ops = {
476 .suspend_late = davinci_mdio_suspend,
477 .resume_early = davinci_mdio_resume,
480 static const struct of_device_id davinci_mdio_of_mtable[] = {
481 { .compatible = "ti,davinci_mdio", },
484 MODULE_DEVICE_TABLE(of, davinci_mdio_of_mtable);
486 static struct platform_driver davinci_mdio_driver = {
488 .name = "davinci_mdio",
489 .owner = THIS_MODULE,
490 .pm = &davinci_mdio_pm_ops,
491 .of_match_table = of_match_ptr(davinci_mdio_of_mtable),
493 .probe = davinci_mdio_probe,
494 .remove = davinci_mdio_remove,
497 static int __init davinci_mdio_init(void)
499 return platform_driver_register(&davinci_mdio_driver);
501 device_initcall(davinci_mdio_init);
503 static void __exit davinci_mdio_exit(void)
505 platform_driver_unregister(&davinci_mdio_driver);
507 module_exit(davinci_mdio_exit);
509 MODULE_LICENSE("GPL");
510 MODULE_DESCRIPTION("DaVinci MDIO driver");