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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 | // SPDX-License-Identifier: GPL-2.0 /* * Watchdog timer driver for the WinSystems EBC-C384 * Copyright (C) 2016 William Breathitt Gray */ #include <linux/device.h> #include <linux/dmi.h> #include <linux/errno.h> #include <linux/io.h> #include <linux/ioport.h> #include <linux/isa.h> #include <linux/kernel.h> #include <linux/module.h> #include <linux/moduleparam.h> #include <linux/types.h> #include <linux/watchdog.h> #define MODULE_NAME "ebc-c384_wdt" #define WATCHDOG_TIMEOUT 60 /* * The timeout value in minutes must fit in a single byte when sent to the * watchdog timer; the maximum timeout possible is 15300 (255 * 60) seconds. */ #define WATCHDOG_MAX_TIMEOUT 15300 #define BASE_ADDR 0x564 #define ADDR_EXTENT 5 #define CFG_ADDR (BASE_ADDR + 1) #define PET_ADDR (BASE_ADDR + 2) static bool nowayout = WATCHDOG_NOWAYOUT; module_param(nowayout, bool, 0); MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); static unsigned timeout; module_param(timeout, uint, 0); MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds (default=" __MODULE_STRING(WATCHDOG_TIMEOUT) ")"); static int ebc_c384_wdt_start(struct watchdog_device *wdev) { unsigned t = wdev->timeout; /* resolution is in minutes for timeouts greater than 255 seconds */ if (t > 255) t = DIV_ROUND_UP(t, 60); outb(t, PET_ADDR); return 0; } static int ebc_c384_wdt_stop(struct watchdog_device *wdev) { outb(0x00, PET_ADDR); return 0; } static int ebc_c384_wdt_set_timeout(struct watchdog_device *wdev, unsigned t) { /* resolution is in minutes for timeouts greater than 255 seconds */ if (t > 255) { /* round second resolution up to minute granularity */ wdev->timeout = roundup(t, 60); /* set watchdog timer for minutes */ outb(0x00, CFG_ADDR); } else { wdev->timeout = t; /* set watchdog timer for seconds */ outb(0x80, CFG_ADDR); } return 0; } static const struct watchdog_ops ebc_c384_wdt_ops = { .start = ebc_c384_wdt_start, .stop = ebc_c384_wdt_stop, .set_timeout = ebc_c384_wdt_set_timeout }; static const struct watchdog_info ebc_c384_wdt_info = { .options = WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE | WDIOF_SETTIMEOUT, .identity = MODULE_NAME }; static int ebc_c384_wdt_probe(struct device *dev, unsigned int id) { struct watchdog_device *wdd; if (!devm_request_region(dev, BASE_ADDR, ADDR_EXTENT, dev_name(dev))) { dev_err(dev, "Unable to lock port addresses (0x%X-0x%X)\n", BASE_ADDR, BASE_ADDR + ADDR_EXTENT); return -EBUSY; } wdd = devm_kzalloc(dev, sizeof(*wdd), GFP_KERNEL); if (!wdd) return -ENOMEM; wdd->info = &ebc_c384_wdt_info; wdd->ops = &ebc_c384_wdt_ops; wdd->timeout = WATCHDOG_TIMEOUT; wdd->min_timeout = 1; wdd->max_timeout = WATCHDOG_MAX_TIMEOUT; watchdog_set_nowayout(wdd, nowayout); watchdog_init_timeout(wdd, timeout, dev); return devm_watchdog_register_device(dev, wdd); } static struct isa_driver ebc_c384_wdt_driver = { .probe = ebc_c384_wdt_probe, .driver = { .name = MODULE_NAME }, }; static int __init ebc_c384_wdt_init(void) { if (!dmi_match(DMI_BOARD_NAME, "EBC-C384 SBC")) return -ENODEV; return isa_register_driver(&ebc_c384_wdt_driver, 1); } static void __exit ebc_c384_wdt_exit(void) { isa_unregister_driver(&ebc_c384_wdt_driver); } module_init(ebc_c384_wdt_init); module_exit(ebc_c384_wdt_exit); MODULE_AUTHOR("William Breathitt Gray <vilhelm.gray@gmail.com>"); MODULE_DESCRIPTION("WinSystems EBC-C384 watchdog timer driver"); MODULE_LICENSE("GPL v2"); MODULE_ALIAS("isa:" MODULE_NAME); |