1 /* 2 * Watchdog driver for DA9063 PMICs. 3 * 4 * Copyright(c) 2012 Dialog Semiconductor Ltd. 5 * 6 * Author: Mariusz Wojtasik <mariusz.wojtasik@diasemi.com> 7 * 8 * This program is free software; you can redistribute it and/or modify it 9 * under the terms of the GNU General Public License as published by the 10 * Free Software Foundation; either version 2 of the License, or (at your 11 * option) any later version. 12 */ 13 14 #include <linux/kernel.h> 15 #include <linux/module.h> 16 #include <linux/watchdog.h> 17 #include <linux/platform_device.h> 18 #include <linux/uaccess.h> 19 #include <linux/slab.h> 20 #include <linux/delay.h> 21 #include <linux/mfd/da9063/registers.h> 22 #include <linux/mfd/da9063/core.h> 23 #include <linux/reboot.h> 24 #include <linux/regmap.h> 25 26 /* 27 * Watchdog selector to timeout in seconds. 28 * 0: WDT disabled; 29 * others: timeout = 2048 ms * 2^(TWDSCALE-1). 30 */ 31 static const unsigned int wdt_timeout[] = { 0, 2, 4, 8, 16, 32, 65, 131 }; 32 #define DA9063_TWDSCALE_DISABLE 0 33 #define DA9063_TWDSCALE_MIN 1 34 #define DA9063_TWDSCALE_MAX (ARRAY_SIZE(wdt_timeout) - 1) 35 #define DA9063_WDT_MIN_TIMEOUT wdt_timeout[DA9063_TWDSCALE_MIN] 36 #define DA9063_WDT_MAX_TIMEOUT wdt_timeout[DA9063_TWDSCALE_MAX] 37 #define DA9063_WDG_TIMEOUT wdt_timeout[3] 38 39 struct da9063_watchdog { 40 struct da9063 *da9063; 41 struct watchdog_device wdtdev; 42 struct notifier_block restart_handler; 43 }; 44 45 static unsigned int da9063_wdt_timeout_to_sel(unsigned int secs) 46 { 47 unsigned int i; 48 49 for (i = DA9063_TWDSCALE_MIN; i <= DA9063_TWDSCALE_MAX; i++) { 50 if (wdt_timeout[i] >= secs) 51 return i; 52 } 53 54 return DA9063_TWDSCALE_MAX; 55 } 56 57 static int _da9063_wdt_set_timeout(struct da9063 *da9063, unsigned int regval) 58 { 59 return regmap_update_bits(da9063->regmap, DA9063_REG_CONTROL_D, 60 DA9063_TWDSCALE_MASK, regval); 61 } 62 63 static int da9063_wdt_start(struct watchdog_device *wdd) 64 { 65 struct da9063_watchdog *wdt = watchdog_get_drvdata(wdd); 66 unsigned int selector; 67 int ret; 68 69 selector = da9063_wdt_timeout_to_sel(wdt->wdtdev.timeout); 70 ret = _da9063_wdt_set_timeout(wdt->da9063, selector); 71 if (ret) 72 dev_err(wdt->da9063->dev, "Watchdog failed to start (err = %d)\n", 73 ret); 74 75 return ret; 76 } 77 78 static int da9063_wdt_stop(struct watchdog_device *wdd) 79 { 80 struct da9063_watchdog *wdt = watchdog_get_drvdata(wdd); 81 int ret; 82 83 ret = regmap_update_bits(wdt->da9063->regmap, DA9063_REG_CONTROL_D, 84 DA9063_TWDSCALE_MASK, DA9063_TWDSCALE_DISABLE); 85 if (ret) 86 dev_alert(wdt->da9063->dev, "Watchdog failed to stop (err = %d)\n", 87 ret); 88 89 return ret; 90 } 91 92 static int da9063_wdt_ping(struct watchdog_device *wdd) 93 { 94 struct da9063_watchdog *wdt = watchdog_get_drvdata(wdd); 95 int ret; 96 97 ret = regmap_write(wdt->da9063->regmap, DA9063_REG_CONTROL_F, 98 DA9063_WATCHDOG); 99 if (ret) 100 dev_alert(wdt->da9063->dev, "Failed to ping the watchdog (err = %d)\n", 101 ret); 102 103 return ret; 104 } 105 106 static int da9063_wdt_set_timeout(struct watchdog_device *wdd, 107 unsigned int timeout) 108 { 109 struct da9063_watchdog *wdt = watchdog_get_drvdata(wdd); 110 unsigned int selector; 111 int ret; 112 113 selector = da9063_wdt_timeout_to_sel(timeout); 114 ret = _da9063_wdt_set_timeout(wdt->da9063, selector); 115 if (ret) 116 dev_err(wdt->da9063->dev, "Failed to set watchdog timeout (err = %d)\n", 117 ret); 118 else 119 wdd->timeout = wdt_timeout[selector]; 120 121 return ret; 122 } 123 124 static int da9063_wdt_restart_handler(struct notifier_block *this, 125 unsigned long mode, void *cmd) 126 { 127 struct da9063_watchdog *wdt = container_of(this, 128 struct da9063_watchdog, 129 restart_handler); 130 int ret; 131 132 ret = regmap_write(wdt->da9063->regmap, DA9063_REG_CONTROL_F, 133 DA9063_SHUTDOWN); 134 if (ret) 135 dev_alert(wdt->da9063->dev, "Failed to shutdown (err = %d)\n", 136 ret); 137 138 return NOTIFY_DONE; 139 } 140 141 static const struct watchdog_info da9063_watchdog_info = { 142 .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING, 143 .identity = "DA9063 Watchdog", 144 }; 145 146 static const struct watchdog_ops da9063_watchdog_ops = { 147 .owner = THIS_MODULE, 148 .start = da9063_wdt_start, 149 .stop = da9063_wdt_stop, 150 .ping = da9063_wdt_ping, 151 .set_timeout = da9063_wdt_set_timeout, 152 }; 153 154 static int da9063_wdt_probe(struct platform_device *pdev) 155 { 156 int ret; 157 struct da9063 *da9063; 158 struct da9063_watchdog *wdt; 159 160 if (!pdev->dev.parent) 161 return -EINVAL; 162 163 da9063 = dev_get_drvdata(pdev->dev.parent); 164 if (!da9063) 165 return -EINVAL; 166 167 wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL); 168 if (!wdt) 169 return -ENOMEM; 170 171 wdt->da9063 = da9063; 172 173 wdt->wdtdev.info = &da9063_watchdog_info; 174 wdt->wdtdev.ops = &da9063_watchdog_ops; 175 wdt->wdtdev.min_timeout = DA9063_WDT_MIN_TIMEOUT; 176 wdt->wdtdev.max_timeout = DA9063_WDT_MAX_TIMEOUT; 177 wdt->wdtdev.timeout = DA9063_WDG_TIMEOUT; 178 wdt->wdtdev.parent = &pdev->dev; 179 180 wdt->wdtdev.status = WATCHDOG_NOWAYOUT_INIT_STATUS; 181 182 watchdog_set_drvdata(&wdt->wdtdev, wdt); 183 dev_set_drvdata(&pdev->dev, wdt); 184 185 ret = watchdog_register_device(&wdt->wdtdev); 186 if (ret) 187 return ret; 188 189 wdt->restart_handler.notifier_call = da9063_wdt_restart_handler; 190 wdt->restart_handler.priority = 128; 191 ret = register_restart_handler(&wdt->restart_handler); 192 if (ret) 193 dev_err(wdt->da9063->dev, 194 "Failed to register restart handler (err = %d)\n", ret); 195 196 return 0; 197 } 198 199 static int da9063_wdt_remove(struct platform_device *pdev) 200 { 201 struct da9063_watchdog *wdt = dev_get_drvdata(&pdev->dev); 202 203 unregister_restart_handler(&wdt->restart_handler); 204 205 watchdog_unregister_device(&wdt->wdtdev); 206 207 return 0; 208 } 209 210 static struct platform_driver da9063_wdt_driver = { 211 .probe = da9063_wdt_probe, 212 .remove = da9063_wdt_remove, 213 .driver = { 214 .name = DA9063_DRVNAME_WATCHDOG, 215 }, 216 }; 217 module_platform_driver(da9063_wdt_driver); 218 219 MODULE_AUTHOR("Mariusz Wojtasik <mariusz.wojtasik@diasemi.com>"); 220 MODULE_DESCRIPTION("Watchdog driver for Dialog DA9063"); 221 MODULE_LICENSE("GPL"); 222 MODULE_ALIAS("platform:" DA9063_DRVNAME_WATCHDOG); 223