1 // SPDX-License-Identifier: GPL-2.0-only
3  *      Intel_SCU 0.2:  An Intel SCU IOH Based Watchdog Device
5  *				- AF82MP20 PCH
7  *      Copyright (C) 2009-2010 Intel Corporation. All rights reserved.
17 #include <linux/watchdog.h>
35 #include <asm/intel-mid.h>
48 		"Watchdog timer margin"
56 		"Default Watchdog timer setting"
61 /* After watchdog device is closed, check force_boot. If:
62  * force_boot == 0, then force boot on next watchdog interrupt after close,
69 		"the system immediately if the /dev/watchdog device is closed"
70 		"A value of 0 means that when /dev/watchdog device is closed"
71 		"the watchdog timer will be refreshed for one more interval"
73 		"watchdog timer will reset the system."
92 		pr_crit("System will reset when watchdog timer times out!\n");  in watchdog_fire()
99 	    (new_margin > MAX_TIME - timer_set)) {  in check_timer_margin()
101 			 new_margin, MIN_TIME_CYCLE, MAX_TIME - timer_set);  in check_timer_margin()
102 		return -EINVAL;  in check_timer_margin()
129 		pr_err("Error setting SCU watchdog timer: %x\n", ipc_ret);  in watchdog_set_ipc()
138 /* timer interrupt handler */
149 	/* has the timer been started? If not, then this is spurious */  in watchdog_timer_interrupt()
155 	/* temporarily disable the timer */  in watchdog_timer_interrupt()
158 	/* set the timer to the threshold */  in watchdog_timer_interrupt()
162 	/* allow the timer to run */  in watchdog_timer_interrupt()
171 	/* read eoi register - clears interrupt */  in intel_scu_keepalive()
174 	/* temporarily disable the timer */  in intel_scu_keepalive()
177 	/* set the timer to the soft_threshold */  in intel_scu_keepalive()
181 	/* allow the timer to run */  in intel_scu_keepalive()
202 		timer_margin * watchdog_device.timer_tbl_ptr->freq_hz;  in intel_scu_set_heartbeat()
204 		(watchdog_device.timer_set - timer_margin)  in intel_scu_set_heartbeat()
205 		* watchdog_device.timer_tbl_ptr->freq_hz;  in intel_scu_set_heartbeat()
207 	pr_debug("set_heartbeat: timer freq is %d\n",  in intel_scu_set_heartbeat()
208 		 watchdog_device.timer_tbl_ptr->freq_hz);  in intel_scu_set_heartbeat()
218 	/* watchdog timing come out right. */  in intel_scu_set_heartbeat()
224 	/* temporarily disable the timer */  in intel_scu_set_heartbeat()
232 		/* Make sure the watchdog timer is stopped */  in intel_scu_set_heartbeat()
245 		/* Make sure timer is stopped */  in intel_scu_set_heartbeat()
249 			/* Unable to set timer value */  in intel_scu_set_heartbeat()
250 			pr_err("Unable to set timer\n");  in intel_scu_set_heartbeat()
251 			return -ENODEV;  in intel_scu_set_heartbeat()
254 		/* set the timer to the soft threshold */  in intel_scu_set_heartbeat()
258 		/* read count value before starting timer */  in intel_scu_set_heartbeat()
261 		/* Start the timer */  in intel_scu_set_heartbeat()
277  * /dev/watchdog handling
283 	/* Set flag to indicate that watchdog device is open */  in intel_scu_open()
285 		return -EBUSY;  in intel_scu_open()
289 		return -EPERM;  in intel_scu_open()
297 	 * This watchdog should not be closed, after the timer  in intel_scu_release()
300 	 * immediate reset. If force_boot is not set, the watchdog  in intel_scu_release()
301 	 * timer is refreshed for one more interval. At the end  in intel_scu_release()
302 	 * of that interval, the watchdog timer will reset the system.  in intel_scu_release()
307 		return -ENOTTY;  in intel_scu_release()
311 		/* Just close, since timer has not been started */  in intel_scu_release()
312 		pr_debug("closed, without starting timer\n");  in intel_scu_release()
316 	pr_crit("Unexpected close of /dev/watchdog!\n");  in intel_scu_release()
318 	/* Since the timer was started, prevent future reopens */  in intel_scu_release()
321 	/* Refresh the timer for one more interval */  in intel_scu_release()
338 		/* Watchdog already started, keep it alive */  in intel_scu_write()
341 		/* Start watchdog with timer value set by init */  in intel_scu_write()
361 		.identity =         "Intel_SCU IOH Watchdog"  /* len < 32 */  in intel_scu_ioctl()
368 				    sizeof(ident)) ? -EFAULT : 0;  in intel_scu_ioctl()
378 			return -EFAULT;  in intel_scu_ioctl()
381 			return -EINVAL;  in intel_scu_ioctl()
384 			return -EINVAL;  in intel_scu_ioctl()
390 		return -ENOTTY;  in intel_scu_ioctl()
402 		/* Turn off the watchdog timer. */  in intel_scu_notify_sys()
426 	 * We don't really need to check this as the SFI timer get will fail  in intel_scu_watchdog_init()
429 	 * If it isn't an intel MID device then it doesn't have this watchdog  in intel_scu_watchdog_init()
432 		return -ENODEV;  in intel_scu_watchdog_init()
438 	    (timer_set > MAX_TIME - MIN_TIME_CYCLE)) {  in intel_scu_watchdog_init()
440 		       timer_set, MIN_TIME_CYCLE, MAX_TIME - MIN_TIME_CYCLE);  in intel_scu_watchdog_init()
441 		return -EINVAL;  in intel_scu_watchdog_init()
446 		return -EINVAL;  in intel_scu_watchdog_init()
448 	watchdog_device.timer_tbl_ptr = sfi_get_mtmr(sfi_mtimer_num-1);  in intel_scu_watchdog_init()
451 		pr_debug("timer is not available\n");  in intel_scu_watchdog_init()
452 		return -ENODEV;  in intel_scu_watchdog_init()
454 	/* make sure the timer exists */  in intel_scu_watchdog_init()
455 	if (watchdog_device.timer_tbl_ptr->phys_addr == 0) {  in intel_scu_watchdog_init()
456 		pr_debug("timer %d does not have valid physical memory\n",  in intel_scu_watchdog_init()
458 		return -ENODEV;  in intel_scu_watchdog_init()
461 	if (watchdog_device.timer_tbl_ptr->irq == 0) {  in intel_scu_watchdog_init()
462 		pr_debug("timer %d invalid irq\n", sfi_mtimer_num);  in intel_scu_watchdog_init()
463 		return -ENODEV;  in intel_scu_watchdog_init()
466 	tmp_addr = ioremap(watchdog_device.timer_tbl_ptr->phys_addr,  in intel_scu_watchdog_init()
470 		pr_debug("timer unable to ioremap\n");  in intel_scu_watchdog_init()
471 		return -ENOMEM;  in intel_scu_watchdog_init()
484 		timer_margin * watchdog_device.timer_tbl_ptr->freq_hz;  in intel_scu_watchdog_init()
486 		(watchdog_device.timer_set - timer_margin)  in intel_scu_watchdog_init()
487 		* watchdog_device.timer_tbl_ptr->freq_hz;  in intel_scu_watchdog_init()
500 	watchdog_device.miscdev.name = "watchdog";  in intel_scu_watchdog_init()
510 	ret = request_irq((unsigned int)watchdog_device.timer_tbl_ptr->irq,  in intel_scu_watchdog_init()
512 		IRQF_SHARED, "watchdog",  in intel_scu_watchdog_init()
518 	/* Make sure timer is disabled before returning */  in intel_scu_watchdog_init()