drivers/watchdog/pnx833x_wdt.c

1 // SPDX-License-Identifier: GPL-2.0-or-later
3  *  PNX833x Hardware Watchdog Driver
8  *  Heavily based upon - IndyDog	0.3
9  *  A Hardware Watchdog Device for SGI IP22
25 #include <linux/watchdog.h>
29 #include <asm/mach-pnx833x/pnx833x.h>
32 #define WATCHDOG_COUNT_FREQUENCY 68000000U /* Watchdog counts at 68MHZ. */
51 MODULE_PARM_DESC(timeout, "Watchdog timeout in Mhz. (68Mhz clock), default="
56 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
62 MODULE_PARM_DESC(start_enabled, "Watchdog is started on module insertion "
67 	/* Enable watchdog causing reset. */  in pnx833x_wdt_start()
72 	/* Enable watchdog. */  in pnx833x_wdt_start()
76 	pr_info("Started watchdog timer\n");  in pnx833x_wdt_start()
81 	/* Disable watchdog causing reset. */  in pnx833x_wdt_stop()
83 	/* Disable watchdog.*/  in pnx833x_wdt_stop()
87 	pr_info("Stopped watchdog timer\n");  in pnx833x_wdt_stop()
102 		return -EBUSY;  in pnx833x_wdt_open()
107 	/* Activate timer */  in pnx833x_wdt_open()
113 	pr_info("Started watchdog timer\n");  in pnx833x_wdt_open()
120 	/* Shut off the timer.  in pnx833x_wdt_release()
131 	/* Refresh the timer. */  in pnx833x_wdt_write()
147 		.identity = "Hardware Watchdog for PNX833x",  in pnx833x_wdt_ioctl()
152 		return -ENOTTY;  in pnx833x_wdt_ioctl()
157 			return -EFAULT;  in pnx833x_wdt_ioctl()
166 			return -EFAULT;  in pnx833x_wdt_ioctl()
183 			return -EFAULT;  in pnx833x_wdt_ioctl()
225 	.name		= "watchdog",
239 	/*If bit 31 is set then watchdog was cause of reset.*/  in watchdog_init()
241 		pr_info("The system was previously reset due to the watchdog firing - please investigate...\n");  in watchdog_init()
258 	pr_info("Hardware Watchdog Timer for PNX833x: Version 0.1\n");  in watchdog_init()
276 MODULE_DESCRIPTION("Hardware Watchdog Device for PNX833x");