1 // SPDX-License-Identifier: GPL-2.0-only
3  * ACPI Hardware Watchdog (WDAT) driver.
14 #include <linux/watchdog.h>
19  * struct wdat_instruction - Single ACPI WDAT instruction
31  * struct wdat_wdt - ACPI WDAT watchdog device
33  * @wdd: Watchdog core device
34  * @period: How long is one watchdog period in ms
35  * @stopped_in_sleep: Is this watchdog stopped by the firmware in S1-S5
36  * @stopped: Was the watchdog stopped by the driver in suspend
54 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
59 static int timeout = WDAT_DEFAULT_TIMEOUT;  variable
60 module_param(timeout, int, 0);
61 MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds (default="
67 	const struct acpi_generic_address *gas = &instr->entry.register_region;  in wdat_wdt_read()
69 	switch (gas->access_width) {  in wdat_wdt_read()
71 		*value = ioread8(instr->reg);  in wdat_wdt_read()
74 		*value = ioread16(instr->reg);  in wdat_wdt_read()
77 		*value = ioread32(instr->reg);  in wdat_wdt_read()
80 		return -EINVAL;  in wdat_wdt_read()
83 	dev_dbg(&wdat->pdev->dev, "Read %#x from 0x%08llx\n", *value,  in wdat_wdt_read()
84 		gas->address);  in wdat_wdt_read()
92 	const struct acpi_generic_address *gas = &instr->entry.register_region;  in wdat_wdt_write()
94 	switch (gas->access_width) {  in wdat_wdt_write()
96 		iowrite8((u8)value, instr->reg);  in wdat_wdt_write()
99 		iowrite16((u16)value, instr->reg);  in wdat_wdt_write()
102 		iowrite32(value, instr->reg);  in wdat_wdt_write()
105 		return -EINVAL;  in wdat_wdt_write()
108 	dev_dbg(&wdat->pdev->dev, "Wrote %#x to 0x%08llx\n", value,  in wdat_wdt_write()
109 		gas->address);  in wdat_wdt_write()
119 	if (action >= ARRAY_SIZE(wdat->instructions))  in wdat_wdt_run_action()
120 		return -EINVAL;  in wdat_wdt_run_action()
122 	if (!wdat->instructions[action])  in wdat_wdt_run_action()
123 		return -EOPNOTSUPP;  in wdat_wdt_run_action()
125 	dev_dbg(&wdat->pdev->dev, "Running action %#x\n", action);  in wdat_wdt_run_action()
128 	list_for_each_entry(instr, wdat->instructions[action], node) {  in wdat_wdt_run_action()
129 		const struct acpi_wdat_entry *entry = &instr->entry;  in wdat_wdt_run_action()
135 		gas = &entry->register_region;  in wdat_wdt_run_action()
137 		preserve = entry->instruction & ACPI_WDAT_PRESERVE_REGISTER;  in wdat_wdt_run_action()
138 		flags = entry->instruction & ~ACPI_WDAT_PRESERVE_REGISTER;  in wdat_wdt_run_action()
139 		value = entry->value;  in wdat_wdt_run_action()
140 		mask = entry->mask;  in wdat_wdt_run_action()
147 			x >>= gas->bit_offset;  in wdat_wdt_run_action()
157 			x >>= gas->bit_offset;  in wdat_wdt_run_action()
165 			x <<= gas->bit_offset;  in wdat_wdt_run_action()
170 				y = y & ~(mask << gas->bit_offset);  in wdat_wdt_run_action()
181 			x <<= gas->bit_offset;  in wdat_wdt_run_action()
186 				y = y & ~(mask << gas->bit_offset);  in wdat_wdt_run_action()
195 			dev_err(&wdat->pdev->dev, "Unknown instruction: %u\n",  in wdat_wdt_run_action()
197 			return -EINVAL;  in wdat_wdt_run_action()
209 	 * WDAT specification says that the watchdog is required to reboot  in wdat_wdt_enable_reboot()
215 	if (ret && ret != -EOPNOTSUPP) {  in wdat_wdt_enable_reboot()
216 		dev_err(&wdat->pdev->dev,  in wdat_wdt_enable_reboot()
217 			"Failed to enable reboot when watchdog triggers\n");  in wdat_wdt_enable_reboot()
230 	if (ret && ret != -EOPNOTSUPP) {  in wdat_wdt_boot_status()
231 		dev_err(&wdat->pdev->dev, "Failed to read boot status\n");  in wdat_wdt_boot_status()
236 		wdat->wdd.bootstatus = WDIOF_CARDRESET;  in wdat_wdt_boot_status()
240 	if (ret && ret != -EOPNOTSUPP)  in wdat_wdt_boot_status()
241 		dev_err(&wdat->pdev->dev, "Failed to clear boot status\n");  in wdat_wdt_boot_status()
251 	if (ret && ret != -EOPNOTSUPP)  in wdat_wdt_set_running()
252 		dev_err(&wdat->pdev->dev, "Failed to read running state\n");  in wdat_wdt_set_running()
255 		set_bit(WDOG_HW_RUNNING, &wdat->wdd.status);  in wdat_wdt_set_running()
276 				unsigned int timeout)  in wdat_wdt_set_timeout()  argument
282 	periods = timeout * 1000 / wdat->period;  in wdat_wdt_set_timeout()
285 		wdd->timeout = timeout;  in wdat_wdt_set_timeout()
295 	return periods * wdat->period / 1000;  in wdat_wdt_get_timeleft()
314 	struct device *dev = &pdev->dev;  in wdat_wdt_probe()
326 		return -ENODEV;  in wdat_wdt_probe()
330 		return -ENOMEM;  in wdat_wdt_probe()
332 	regs = devm_kcalloc(dev, pdev->num_resources, sizeof(*regs),  in wdat_wdt_probe()
335 		return -ENOMEM;  in wdat_wdt_probe()
337 	/* WDAT specification wants to have >= 1ms period */  in wdat_wdt_probe()
338 	if (tbl->timer_period < 1)  in wdat_wdt_probe()
339 		return -EINVAL;  in wdat_wdt_probe()
340 	if (tbl->min_count > tbl->max_count)  in wdat_wdt_probe()
341 		return -EINVAL;  in wdat_wdt_probe()
343 	wdat->period = tbl->timer_period;  in wdat_wdt_probe()
344 	wdat->wdd.min_timeout = DIV_ROUND_UP(wdat->period * tbl->min_count, 1000);  in wdat_wdt_probe()
345 	wdat->wdd.max_timeout = wdat->period * tbl->max_count / 1000;  in wdat_wdt_probe()
346 	wdat->stopped_in_sleep = tbl->flags & ACPI_WDAT_STOPPED;  in wdat_wdt_probe()
347 	wdat->wdd.info = &wdat_wdt_info;  in wdat_wdt_probe()
348 	wdat->wdd.ops = &wdat_wdt_ops;  in wdat_wdt_probe()
349 	wdat->pdev = pdev;  in wdat_wdt_probe()
352 	for (i = 0; i < pdev->num_resources; i++) {  in wdat_wdt_probe()
355 		res = &pdev->resource[i];  in wdat_wdt_probe()
361 			reg = devm_ioport_map(dev, res->start, 1);  in wdat_wdt_probe()
363 				return -ENOMEM;  in wdat_wdt_probe()
366 			return -EINVAL;  in wdat_wdt_probe()
373 	for (i = 0; i < tbl->entries; i++) {  in wdat_wdt_probe()
389 			return -ENOMEM;  in wdat_wdt_probe()
391 		INIT_LIST_HEAD(&instr->node);  in wdat_wdt_probe()
392 		instr->entry = entries[i];  in wdat_wdt_probe()
397 		r.start = gas->address;  in wdat_wdt_probe()
398 		r.end = r.start + ACPI_ACCESS_BYTE_WIDTH(gas->access_width) - 1;  in wdat_wdt_probe()
399 		if (gas->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) {  in wdat_wdt_probe()
401 		} else if (gas->space_id == ACPI_ADR_SPACE_SYSTEM_IO) {  in wdat_wdt_probe()
405 				gas->space_id);  in wdat_wdt_probe()
410 		for (j = 0; j < pdev->num_resources; j++) {  in wdat_wdt_probe()
411 			res = &pdev->resource[j];  in wdat_wdt_probe()
413 				instr->reg = regs[j] + r.start - res->start;  in wdat_wdt_probe()
418 		if (!instr->reg) {  in wdat_wdt_probe()
420 			return -EINVAL;  in wdat_wdt_probe()
423 		instructions = wdat->instructions[action];  in wdat_wdt_probe()
429 				return -ENOMEM;  in wdat_wdt_probe()
432 			wdat->instructions[action] = instructions;  in wdat_wdt_probe()
435 		list_add_tail(&instr->node, instructions);  in wdat_wdt_probe()
438 	if (wdat->instructions[ACPI_WDAT_GET_CURRENT_COUNTDOWN])  in wdat_wdt_probe()
451 	 * Set initial timeout so that userspace has time to configure the  in wdat_wdt_probe()
452 	 * watchdog properly after it has opened the device. In some cases  in wdat_wdt_probe()
455 	if (watchdog_timeout_invalid(&wdat->wdd, timeout)) {  in wdat_wdt_probe()
456 		dev_warn(dev, "Invalid timeout %d given, using %d\n",  in wdat_wdt_probe()
457 			 timeout, WDAT_DEFAULT_TIMEOUT);  in wdat_wdt_probe()
458 		timeout = WDAT_DEFAULT_TIMEOUT;  in wdat_wdt_probe()
461 	ret = wdat_wdt_set_timeout(&wdat->wdd, timeout);  in wdat_wdt_probe()
465 	watchdog_set_nowayout(&wdat->wdd, nowayout);  in wdat_wdt_probe()
466 	watchdog_stop_on_reboot(&wdat->wdd);  in wdat_wdt_probe()
467 	watchdog_stop_on_unregister(&wdat->wdd);  in wdat_wdt_probe()
468 	return devm_watchdog_register_device(dev, &wdat->wdd);  in wdat_wdt_probe()
476 	if (!watchdog_active(&wdat->wdd))  in wdat_wdt_suspend_noirq()
480 	 * We need to stop the watchdog if firmware is not doing it or if we  in wdat_wdt_suspend_noirq()
482 	 * firmware is stopping the watchdog we kick it here one more time  in wdat_wdt_suspend_noirq()
485 	wdat->stopped = false;  in wdat_wdt_suspend_noirq()
487 	    !wdat->stopped_in_sleep) {  in wdat_wdt_suspend_noirq()
488 		ret = wdat_wdt_stop(&wdat->wdd);  in wdat_wdt_suspend_noirq()
490 			wdat->stopped = true;  in wdat_wdt_suspend_noirq()
492 		ret = wdat_wdt_ping(&wdat->wdd);  in wdat_wdt_suspend_noirq()
503 	if (!watchdog_active(&wdat->wdd))  in wdat_wdt_resume_noirq()
506 	if (!wdat->stopped) {  in wdat_wdt_resume_noirq()
508 		 * Looks like the boot firmware reinitializes the watchdog  in wdat_wdt_resume_noirq()
510 		 * stop and reprogram the watchdog here.  in wdat_wdt_resume_noirq()
512 		ret = wdat_wdt_stop(&wdat->wdd);  in wdat_wdt_resume_noirq()
516 		ret = wdat_wdt_set_timeout(&wdat->wdd, wdat->wdd.timeout);  in wdat_wdt_resume_noirq()
524 		ret = wdat_wdt_ping(&wdat->wdd);  in wdat_wdt_resume_noirq()
529 	return wdat_wdt_start(&wdat->wdd);  in wdat_wdt_resume_noirq()
547 MODULE_DESCRIPTION("ACPI Hardware Watchdog (WDAT) driver");