2 * drivers/watchdog/orion_wdt.c
4 * Watchdog driver for Orion/Kirkwood processors
6 * Author: Sylver Bruneau <sylver.bruneau@googlemail.com>
8 * This file is licensed under the terms of the GNU General Public
9 * License version 2. This program is licensed "as is" without any
10 * warranty of any kind, whether express or implied.
13 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
15 #include <linux/module.h>
16 #include <linux/moduleparam.h>
17 #include <linux/types.h>
18 #include <linux/kernel.h>
19 #include <linux/platform_device.h>
20 #include <linux/watchdog.h>
21 #include <linux/interrupt.h>
23 #include <linux/clk.h>
24 #include <linux/err.h>
26 #include <linux/of_device.h>
28 /* RSTOUT mask register physical address for Orion5x, Kirkwood and Dove */
29 #define ORION_RSTOUT_MASK_OFFSET 0x20108
31 /* Internal registers can be configured at any 1 MiB aligned address */
32 #define INTERNAL_REGS_MASK ~(SZ_1M - 1)
35 * Watchdog timer block registers.
37 #define TIMER_CTRL 0x0000
38 #define TIMER_A370_STATUS 0x04
40 #define WDT_MAX_CYCLE_COUNT 0xffffffff
42 #define WDT_A370_RATIO_MASK(v) ((v) << 16)
43 #define WDT_A370_RATIO_SHIFT 5
44 #define WDT_A370_RATIO (1 << WDT_A370_RATIO_SHIFT)
46 #define WDT_AXP_FIXED_ENABLE_BIT BIT(10)
47 #define WDT_A370_EXPIRED BIT(31)
49 static bool nowayout = WATCHDOG_NOWAYOUT;
50 static int heartbeat = -1; /* module parameter (seconds) */
52 struct orion_watchdog;
54 struct orion_watchdog_data {
55 int wdt_counter_offset;
57 int rstout_enable_bit;
58 int (*clock_init)(struct platform_device *,
59 struct orion_watchdog *);
60 int (*enabled)(struct orion_watchdog *);
61 int (*start)(struct watchdog_device *);
62 int (*stop)(struct watchdog_device *);
65 struct orion_watchdog {
66 struct watchdog_device wdt;
69 unsigned long clk_rate;
71 const struct orion_watchdog_data *data;
74 static int orion_wdt_clock_init(struct platform_device *pdev,
75 struct orion_watchdog *dev)
79 dev->clk = clk_get(&pdev->dev, NULL);
81 return PTR_ERR(dev->clk);
82 ret = clk_prepare_enable(dev->clk);
88 dev->clk_rate = clk_get_rate(dev->clk);
92 static int armada370_wdt_clock_init(struct platform_device *pdev,
93 struct orion_watchdog *dev)
97 dev->clk = clk_get(&pdev->dev, NULL);
99 return PTR_ERR(dev->clk);
100 ret = clk_prepare_enable(dev->clk);
106 /* Setup watchdog input clock */
107 atomic_io_modify(dev->reg + TIMER_CTRL,
108 WDT_A370_RATIO_MASK(WDT_A370_RATIO_SHIFT),
109 WDT_A370_RATIO_MASK(WDT_A370_RATIO_SHIFT));
111 dev->clk_rate = clk_get_rate(dev->clk) / WDT_A370_RATIO;
115 static int armadaxp_wdt_clock_init(struct platform_device *pdev,
116 struct orion_watchdog *dev)
120 dev->clk = of_clk_get_by_name(pdev->dev.of_node, "fixed");
121 if (IS_ERR(dev->clk))
122 return PTR_ERR(dev->clk);
123 ret = clk_prepare_enable(dev->clk);
129 /* Enable the fixed watchdog clock input */
130 atomic_io_modify(dev->reg + TIMER_CTRL,
131 WDT_AXP_FIXED_ENABLE_BIT,
132 WDT_AXP_FIXED_ENABLE_BIT);
134 dev->clk_rate = clk_get_rate(dev->clk);
138 static int orion_wdt_ping(struct watchdog_device *wdt_dev)
140 struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
141 /* Reload watchdog duration */
142 writel(dev->clk_rate * wdt_dev->timeout,
143 dev->reg + dev->data->wdt_counter_offset);
147 static int armada370_start(struct watchdog_device *wdt_dev)
149 struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
152 /* Set watchdog duration */
153 writel(dev->clk_rate * wdt_dev->timeout,
154 dev->reg + dev->data->wdt_counter_offset);
156 /* Clear the watchdog expiration bit */
157 atomic_io_modify(dev->reg + TIMER_A370_STATUS, WDT_A370_EXPIRED, 0);
159 /* Enable watchdog timer */
160 atomic_io_modify(dev->reg + TIMER_CTRL, dev->data->wdt_enable_bit,
161 dev->data->wdt_enable_bit);
163 /* Enable reset on watchdog */
164 reg = readl(dev->rstout);
165 reg |= dev->data->rstout_enable_bit;
166 writel(reg, dev->rstout);
170 static int orion_start(struct watchdog_device *wdt_dev)
172 struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
174 /* Set watchdog duration */
175 writel(dev->clk_rate * wdt_dev->timeout,
176 dev->reg + dev->data->wdt_counter_offset);
178 /* Enable watchdog timer */
179 atomic_io_modify(dev->reg + TIMER_CTRL, dev->data->wdt_enable_bit,
180 dev->data->wdt_enable_bit);
182 /* Enable reset on watchdog */
183 atomic_io_modify(dev->rstout, dev->data->rstout_enable_bit,
184 dev->data->rstout_enable_bit);
189 static int orion_wdt_start(struct watchdog_device *wdt_dev)
191 struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
193 /* There are some per-SoC quirks to handle */
194 return dev->data->start(wdt_dev);
197 static int orion_stop(struct watchdog_device *wdt_dev)
199 struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
201 /* Disable reset on watchdog */
202 atomic_io_modify(dev->rstout, dev->data->rstout_enable_bit, 0);
204 /* Disable watchdog timer */
205 atomic_io_modify(dev->reg + TIMER_CTRL, dev->data->wdt_enable_bit, 0);
210 static int armada370_stop(struct watchdog_device *wdt_dev)
212 struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
215 /* Disable reset on watchdog */
216 reg = readl(dev->rstout);
217 reg &= ~dev->data->rstout_enable_bit;
218 writel(reg, dev->rstout);
220 /* Disable watchdog timer */
221 atomic_io_modify(dev->reg + TIMER_CTRL, dev->data->wdt_enable_bit, 0);
226 static int orion_wdt_stop(struct watchdog_device *wdt_dev)
228 struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
230 return dev->data->stop(wdt_dev);
233 static int orion_enabled(struct orion_watchdog *dev)
235 bool enabled, running;
237 enabled = readl(dev->rstout) & dev->data->rstout_enable_bit;
238 running = readl(dev->reg + TIMER_CTRL) & dev->data->wdt_enable_bit;
240 return enabled && running;
243 static int orion_wdt_enabled(struct watchdog_device *wdt_dev)
245 struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
247 return dev->data->enabled(dev);
250 static unsigned int orion_wdt_get_timeleft(struct watchdog_device *wdt_dev)
252 struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
253 return readl(dev->reg + dev->data->wdt_counter_offset) / dev->clk_rate;
256 static int orion_wdt_set_timeout(struct watchdog_device *wdt_dev,
257 unsigned int timeout)
259 wdt_dev->timeout = timeout;
263 static const struct watchdog_info orion_wdt_info = {
264 .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
265 .identity = "Orion Watchdog",
268 static const struct watchdog_ops orion_wdt_ops = {
269 .owner = THIS_MODULE,
270 .start = orion_wdt_start,
271 .stop = orion_wdt_stop,
272 .ping = orion_wdt_ping,
273 .set_timeout = orion_wdt_set_timeout,
274 .get_timeleft = orion_wdt_get_timeleft,
277 static irqreturn_t orion_wdt_irq(int irq, void *devid)
279 panic("Watchdog Timeout");
284 * The original devicetree binding for this driver specified only
285 * one memory resource, so in order to keep DT backwards compatibility
286 * we try to fallback to a hardcoded register address, if the resource
287 * is missing from the devicetree.
289 static void __iomem *orion_wdt_ioremap_rstout(struct platform_device *pdev,
290 phys_addr_t internal_regs)
292 struct resource *res;
295 res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
297 return devm_ioremap(&pdev->dev, res->start,
300 rstout = internal_regs + ORION_RSTOUT_MASK_OFFSET;
302 WARN(1, FW_BUG "falling back to harcoded RSTOUT reg %pa\n", &rstout);
303 return devm_ioremap(&pdev->dev, rstout, 0x4);
306 static const struct orion_watchdog_data orion_data = {
307 .rstout_enable_bit = BIT(1),
308 .wdt_enable_bit = BIT(4),
309 .wdt_counter_offset = 0x24,
310 .clock_init = orion_wdt_clock_init,
311 .enabled = orion_enabled,
312 .start = orion_start,
316 static const struct orion_watchdog_data armada370_data = {
317 .rstout_enable_bit = BIT(8),
318 .wdt_enable_bit = BIT(8),
319 .wdt_counter_offset = 0x34,
320 .clock_init = armada370_wdt_clock_init,
321 .enabled = orion_enabled,
322 .start = armada370_start,
323 .stop = armada370_stop,
326 static const struct orion_watchdog_data armadaxp_data = {
327 .rstout_enable_bit = BIT(8),
328 .wdt_enable_bit = BIT(8),
329 .wdt_counter_offset = 0x34,
330 .clock_init = armadaxp_wdt_clock_init,
331 .enabled = orion_enabled,
332 .start = armada370_start,
333 .stop = armada370_stop,
336 static const struct of_device_id orion_wdt_of_match_table[] = {
338 .compatible = "marvell,orion-wdt",
342 .compatible = "marvell,armada-370-wdt",
343 .data = &armada370_data,
346 .compatible = "marvell,armada-xp-wdt",
347 .data = &armadaxp_data,
351 MODULE_DEVICE_TABLE(of, orion_wdt_of_match_table);
353 static int orion_wdt_get_regs(struct platform_device *pdev,
354 struct orion_watchdog *dev)
356 struct device_node *node = pdev->dev.of_node;
357 struct resource *res;
359 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
362 dev->reg = devm_ioremap(&pdev->dev, res->start,
367 /* Each supported compatible has some RSTOUT register quirk */
368 if (of_device_is_compatible(node, "marvell,orion-wdt")) {
370 dev->rstout = orion_wdt_ioremap_rstout(pdev, res->start &
375 } else if (of_device_is_compatible(node, "marvell,armada-370-wdt") ||
376 of_device_is_compatible(node, "marvell,armada-xp-wdt")) {
378 /* Dedicated RSTOUT register, can be requested. */
379 res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
380 dev->rstout = devm_ioremap_resource(&pdev->dev, res);
381 if (IS_ERR(dev->rstout))
382 return PTR_ERR(dev->rstout);
391 static int orion_wdt_probe(struct platform_device *pdev)
393 struct orion_watchdog *dev;
394 const struct of_device_id *match;
395 unsigned int wdt_max_duration; /* (seconds) */
398 dev = devm_kzalloc(&pdev->dev, sizeof(struct orion_watchdog),
403 match = of_match_device(orion_wdt_of_match_table, &pdev->dev);
405 /* Default legacy match */
406 match = &orion_wdt_of_match_table[0];
408 dev->wdt.info = &orion_wdt_info;
409 dev->wdt.ops = &orion_wdt_ops;
410 dev->wdt.min_timeout = 1;
411 dev->data = match->data;
413 ret = orion_wdt_get_regs(pdev, dev);
417 ret = dev->data->clock_init(pdev, dev);
419 dev_err(&pdev->dev, "cannot initialize clock\n");
423 wdt_max_duration = WDT_MAX_CYCLE_COUNT / dev->clk_rate;
425 dev->wdt.timeout = wdt_max_duration;
426 dev->wdt.max_timeout = wdt_max_duration;
427 watchdog_init_timeout(&dev->wdt, heartbeat, &pdev->dev);
429 platform_set_drvdata(pdev, &dev->wdt);
430 watchdog_set_drvdata(&dev->wdt, dev);
433 * Let's make sure the watchdog is fully stopped, unless it's
434 * explicitly enabled. This may be the case if the module was
435 * removed and re-insterted, or if the bootloader explicitly
436 * set a running watchdog before booting the kernel.
438 if (!orion_wdt_enabled(&dev->wdt))
439 orion_wdt_stop(&dev->wdt);
441 /* Request the IRQ only after the watchdog is disabled */
442 irq = platform_get_irq(pdev, 0);
445 * Not all supported platforms specify an interrupt for the
446 * watchdog, so let's make it optional.
448 ret = devm_request_irq(&pdev->dev, irq, orion_wdt_irq, 0,
451 dev_err(&pdev->dev, "failed to request IRQ\n");
456 watchdog_set_nowayout(&dev->wdt, nowayout);
457 ret = watchdog_register_device(&dev->wdt);
461 pr_info("Initial timeout %d sec%s\n",
462 dev->wdt.timeout, nowayout ? ", nowayout" : "");
466 clk_disable_unprepare(dev->clk);
471 static int orion_wdt_remove(struct platform_device *pdev)
473 struct watchdog_device *wdt_dev = platform_get_drvdata(pdev);
474 struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
476 watchdog_unregister_device(wdt_dev);
477 clk_disable_unprepare(dev->clk);
482 static void orion_wdt_shutdown(struct platform_device *pdev)
484 struct watchdog_device *wdt_dev = platform_get_drvdata(pdev);
485 orion_wdt_stop(wdt_dev);
488 static struct platform_driver orion_wdt_driver = {
489 .probe = orion_wdt_probe,
490 .remove = orion_wdt_remove,
491 .shutdown = orion_wdt_shutdown,
493 .owner = THIS_MODULE,
495 .of_match_table = orion_wdt_of_match_table,
499 module_platform_driver(orion_wdt_driver);
501 MODULE_AUTHOR("Sylver Bruneau <sylver.bruneau@googlemail.com>");
502 MODULE_DESCRIPTION("Orion Processor Watchdog");
504 module_param(heartbeat, int, 0);
505 MODULE_PARM_DESC(heartbeat, "Initial watchdog heartbeat in seconds");
507 module_param(nowayout, bool, 0);
508 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
509 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
511 MODULE_LICENSE("GPL");
512 MODULE_ALIAS("platform:orion_wdt");