1 // SPDX-License-Identifier: GPL-2.0+
3 * DaVinci MDIO Module driver
5 * Copyright (C) 2010 Texas Instruments.
7 * Shamelessly ripped out of davinci_emac.c, original copyrights follow:
9 * Copyright (C) 2009 Texas Instruments.
12 #include <linux/module.h>
13 #include <linux/kernel.h>
14 #include <linux/platform_device.h>
15 #include <linux/delay.h>
16 #include <linux/sched.h>
17 #include <linux/slab.h>
18 #include <linux/phy.h>
19 #include <linux/clk.h>
20 #include <linux/err.h>
22 #include <linux/iopoll.h>
23 #include <linux/pm_runtime.h>
24 #include <linux/davinci_emac.h>
26 #include <linux/of_device.h>
27 #include <linux/of_mdio.h>
28 #include <linux/pinctrl/consumer.h>
31 * This timeout definition is a worst-case ultra defensive measure against
32 * unexpected controller lock ups. Ideally, we should never ever hit this
33 * scenario in practice.
35 #define MDIO_TIMEOUT 100 /* msecs */
37 #define PHY_REG_MASK 0x1f
38 #define PHY_ID_MASK 0x1f
40 #define DEF_OUT_FREQ 2200000 /* 2.2 MHz */
42 struct davinci_mdio_of_param {
43 int autosuspend_delay_ms;
46 struct davinci_mdio_regs {
49 #define CONTROL_IDLE BIT(31)
50 #define CONTROL_ENABLE BIT(30)
51 #define CONTROL_MAX_DIV (0xffff)
66 #define USERACCESS_GO BIT(31)
67 #define USERACCESS_WRITE BIT(30)
68 #define USERACCESS_ACK BIT(29)
69 #define USERACCESS_READ (0)
70 #define USERACCESS_DATA (0xffff)
76 static const struct mdio_platform_data default_pdata = {
77 .bus_freq = DEF_OUT_FREQ,
80 struct davinci_mdio_data {
81 struct mdio_platform_data pdata;
82 struct davinci_mdio_regs __iomem *regs;
86 bool active_in_suspend;
87 unsigned long access_time; /* jiffies */
88 /* Indicates that driver shouldn't modify phy_mask in case
89 * if MDIO bus is registered from DT.
95 static void davinci_mdio_init_clk(struct davinci_mdio_data *data)
97 u32 mdio_in, div, mdio_out_khz, access_time;
99 mdio_in = clk_get_rate(data->clk);
100 div = (mdio_in / data->pdata.bus_freq) - 1;
101 if (div > CONTROL_MAX_DIV)
102 div = CONTROL_MAX_DIV;
106 * One mdio transaction consists of:
107 * 32 bits of preamble
108 * 32 bits of transferred data
109 * 24 bits of bus yield (not needed unless shared?)
111 mdio_out_khz = mdio_in / (1000 * (div + 1));
112 access_time = (88 * 1000) / mdio_out_khz;
115 * In the worst case, we could be kicking off a user-access immediately
116 * after the mdio bus scan state-machine triggered its own read. If
117 * so, our request could get deferred by one access cycle. We
118 * defensively allow for 4 access cycles.
120 data->access_time = usecs_to_jiffies(access_time * 4);
121 if (!data->access_time)
122 data->access_time = 1;
125 static void davinci_mdio_enable(struct davinci_mdio_data *data)
127 /* set enable and clock divider */
128 writel(data->clk_div | CONTROL_ENABLE, &data->regs->control);
131 static int davinci_mdio_reset(struct mii_bus *bus)
133 struct davinci_mdio_data *data = bus->priv;
137 ret = pm_runtime_get_sync(data->dev);
139 pm_runtime_put_noidle(data->dev);
143 /* wait for scan logic to settle */
144 msleep(PHY_MAX_ADDR * data->access_time);
146 /* dump hardware version info */
147 ver = readl(&data->regs->version);
149 "davinci mdio revision %d.%d, bus freq %ld\n",
150 (ver >> 8) & 0xff, ver & 0xff,
151 data->pdata.bus_freq);
156 /* get phy mask from the alive register */
157 phy_mask = readl(&data->regs->alive);
159 /* restrict mdio bus to live phys only */
160 dev_info(data->dev, "detected phy mask %x\n", ~phy_mask);
161 phy_mask = ~phy_mask;
163 /* desperately scan all phys */
164 dev_warn(data->dev, "no live phy, scanning all\n");
167 data->bus->phy_mask = phy_mask;
170 pm_runtime_mark_last_busy(data->dev);
171 pm_runtime_put_autosuspend(data->dev);
176 /* wait until hardware is ready for another user access */
177 static inline int wait_for_user_access(struct davinci_mdio_data *data)
179 struct davinci_mdio_regs __iomem *regs = data->regs;
180 unsigned long timeout = jiffies + msecs_to_jiffies(MDIO_TIMEOUT);
183 while (time_after(timeout, jiffies)) {
184 reg = readl(®s->user[0].access);
185 if ((reg & USERACCESS_GO) == 0)
188 reg = readl(®s->control);
189 if ((reg & CONTROL_IDLE) == 0) {
190 usleep_range(100, 200);
195 * An emac soft_reset may have clobbered the mdio controller's
196 * state machine. We need to reset and retry the current
199 dev_warn(data->dev, "resetting idled controller\n");
200 davinci_mdio_enable(data);
204 reg = readl(®s->user[0].access);
205 if ((reg & USERACCESS_GO) == 0)
208 dev_err(data->dev, "timed out waiting for user access\n");
212 /* wait until hardware state machine is idle */
213 static inline int wait_for_idle(struct davinci_mdio_data *data)
215 struct davinci_mdio_regs __iomem *regs = data->regs;
218 ret = readl_poll_timeout(®s->control, val, val & CONTROL_IDLE,
219 0, MDIO_TIMEOUT * 1000);
221 dev_err(data->dev, "timed out waiting for idle\n");
226 static int davinci_mdio_read(struct mii_bus *bus, int phy_id, int phy_reg)
228 struct davinci_mdio_data *data = bus->priv;
232 if (phy_reg & ~PHY_REG_MASK || phy_id & ~PHY_ID_MASK)
235 ret = pm_runtime_get_sync(data->dev);
237 pm_runtime_put_noidle(data->dev);
241 reg = (USERACCESS_GO | USERACCESS_READ | (phy_reg << 21) |
245 ret = wait_for_user_access(data);
251 writel(reg, &data->regs->user[0].access);
253 ret = wait_for_user_access(data);
259 reg = readl(&data->regs->user[0].access);
260 ret = (reg & USERACCESS_ACK) ? (reg & USERACCESS_DATA) : -EIO;
264 pm_runtime_mark_last_busy(data->dev);
265 pm_runtime_put_autosuspend(data->dev);
269 static int davinci_mdio_write(struct mii_bus *bus, int phy_id,
270 int phy_reg, u16 phy_data)
272 struct davinci_mdio_data *data = bus->priv;
276 if (phy_reg & ~PHY_REG_MASK || phy_id & ~PHY_ID_MASK)
279 ret = pm_runtime_get_sync(data->dev);
281 pm_runtime_put_noidle(data->dev);
285 reg = (USERACCESS_GO | USERACCESS_WRITE | (phy_reg << 21) |
286 (phy_id << 16) | (phy_data & USERACCESS_DATA));
289 ret = wait_for_user_access(data);
295 writel(reg, &data->regs->user[0].access);
297 ret = wait_for_user_access(data);
303 pm_runtime_mark_last_busy(data->dev);
304 pm_runtime_put_autosuspend(data->dev);
309 static int davinci_mdio_probe_dt(struct mdio_platform_data *data,
310 struct platform_device *pdev)
312 struct device_node *node = pdev->dev.of_node;
318 if (of_property_read_u32(node, "bus_freq", &prop)) {
319 dev_err(&pdev->dev, "Missing bus_freq property in the DT.\n");
322 data->bus_freq = prop;
327 #if IS_ENABLED(CONFIG_OF)
328 static const struct davinci_mdio_of_param of_cpsw_mdio_data = {
329 .autosuspend_delay_ms = 100,
332 static const struct of_device_id davinci_mdio_of_mtable[] = {
333 { .compatible = "ti,davinci_mdio", },
334 { .compatible = "ti,cpsw-mdio", .data = &of_cpsw_mdio_data},
337 MODULE_DEVICE_TABLE(of, davinci_mdio_of_mtable);
340 static int davinci_mdio_probe(struct platform_device *pdev)
342 struct mdio_platform_data *pdata = dev_get_platdata(&pdev->dev);
343 struct device *dev = &pdev->dev;
344 struct davinci_mdio_data *data;
345 struct resource *res;
346 struct phy_device *phy;
348 int autosuspend_delay_ms = -1;
350 data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
354 data->bus = devm_mdiobus_alloc(dev);
356 dev_err(dev, "failed to alloc mii bus\n");
360 if (IS_ENABLED(CONFIG_OF) && dev->of_node) {
361 const struct of_device_id *of_id;
363 ret = davinci_mdio_probe_dt(&data->pdata, pdev);
366 snprintf(data->bus->id, MII_BUS_ID_SIZE, "%s", pdev->name);
368 of_id = of_match_device(davinci_mdio_of_mtable, &pdev->dev);
370 const struct davinci_mdio_of_param *of_mdio_data;
372 of_mdio_data = of_id->data;
374 autosuspend_delay_ms =
375 of_mdio_data->autosuspend_delay_ms;
378 data->pdata = pdata ? (*pdata) : default_pdata;
379 snprintf(data->bus->id, MII_BUS_ID_SIZE, "%s-%x",
380 pdev->name, pdev->id);
383 data->bus->name = dev_name(dev);
384 data->bus->read = davinci_mdio_read,
385 data->bus->write = davinci_mdio_write,
386 data->bus->reset = davinci_mdio_reset,
387 data->bus->parent = dev;
388 data->bus->priv = data;
390 data->clk = devm_clk_get(dev, "fck");
391 if (IS_ERR(data->clk)) {
392 dev_err(dev, "failed to get device clock\n");
393 return PTR_ERR(data->clk);
396 dev_set_drvdata(dev, data);
399 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
402 data->regs = devm_ioremap(dev, res->start, resource_size(res));
406 davinci_mdio_init_clk(data);
408 pm_runtime_set_autosuspend_delay(&pdev->dev, autosuspend_delay_ms);
409 pm_runtime_use_autosuspend(&pdev->dev);
410 pm_runtime_enable(&pdev->dev);
412 /* register the mii bus
413 * Create PHYs from DT only in case if PHY child nodes are explicitly
414 * defined to support backward compatibility with DTs which assume that
415 * Davinci MDIO will always scan the bus for PHYs detection.
417 if (dev->of_node && of_get_child_count(dev->of_node))
418 data->skip_scan = true;
420 ret = of_mdiobus_register(data->bus, dev->of_node);
424 /* scan and dump the bus */
425 for (addr = 0; addr < PHY_MAX_ADDR; addr++) {
426 phy = mdiobus_get_phy(data->bus, addr);
428 dev_info(dev, "phy[%d]: device %s, driver %s\n",
429 phy->mdio.addr, phydev_name(phy),
430 phy->drv ? phy->drv->name : "unknown");
437 pm_runtime_dont_use_autosuspend(&pdev->dev);
438 pm_runtime_disable(&pdev->dev);
442 static int davinci_mdio_remove(struct platform_device *pdev)
444 struct davinci_mdio_data *data = platform_get_drvdata(pdev);
447 mdiobus_unregister(data->bus);
449 pm_runtime_dont_use_autosuspend(&pdev->dev);
450 pm_runtime_disable(&pdev->dev);
456 static int davinci_mdio_runtime_suspend(struct device *dev)
458 struct davinci_mdio_data *data = dev_get_drvdata(dev);
461 /* shutdown the scan state machine */
462 ctrl = readl(&data->regs->control);
463 ctrl &= ~CONTROL_ENABLE;
464 writel(ctrl, &data->regs->control);
470 static int davinci_mdio_runtime_resume(struct device *dev)
472 struct davinci_mdio_data *data = dev_get_drvdata(dev);
474 davinci_mdio_enable(data);
479 #ifdef CONFIG_PM_SLEEP
480 static int davinci_mdio_suspend(struct device *dev)
482 struct davinci_mdio_data *data = dev_get_drvdata(dev);
485 data->active_in_suspend = !pm_runtime_status_suspended(dev);
486 if (data->active_in_suspend)
487 ret = pm_runtime_force_suspend(dev);
491 /* Select sleep pin state */
492 pinctrl_pm_select_sleep_state(dev);
497 static int davinci_mdio_resume(struct device *dev)
499 struct davinci_mdio_data *data = dev_get_drvdata(dev);
501 /* Select default pin state */
502 pinctrl_pm_select_default_state(dev);
504 if (data->active_in_suspend)
505 pm_runtime_force_resume(dev);
511 static const struct dev_pm_ops davinci_mdio_pm_ops = {
512 SET_RUNTIME_PM_OPS(davinci_mdio_runtime_suspend,
513 davinci_mdio_runtime_resume, NULL)
514 SET_LATE_SYSTEM_SLEEP_PM_OPS(davinci_mdio_suspend, davinci_mdio_resume)
517 static struct platform_driver davinci_mdio_driver = {
519 .name = "davinci_mdio",
520 .pm = &davinci_mdio_pm_ops,
521 .of_match_table = of_match_ptr(davinci_mdio_of_mtable),
523 .probe = davinci_mdio_probe,
524 .remove = davinci_mdio_remove,
527 static int __init davinci_mdio_init(void)
529 return platform_driver_register(&davinci_mdio_driver);
531 device_initcall(davinci_mdio_init);
533 static void __exit davinci_mdio_exit(void)
535 platform_driver_unregister(&davinci_mdio_driver);
537 module_exit(davinci_mdio_exit);
539 MODULE_LICENSE("GPL");
540 MODULE_DESCRIPTION("DaVinci MDIO driver");