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/regmap.h> 24 25 /* 26 * Watchdog selector to timeout in seconds. 27 * 0: WDT disabled; 28 * others: timeout = 2048 ms * 2^(TWDSCALE-1). 29 */ 30 static const unsigned int wdt_timeout[] = { 0, 2, 4, 8, 16, 32, 65, 131 }; 31 #define DA9063_TWDSCALE_DISABLE 0 32 #define DA9063_TWDSCALE_MIN 1 33 #define DA9063_TWDSCALE_MAX (ARRAY_SIZE(wdt_timeout) - 1) 34 #define DA9063_WDT_MIN_TIMEOUT wdt_timeout[DA9063_TWDSCALE_MIN] 35 #define DA9063_WDT_MAX_TIMEOUT wdt_timeout[DA9063_TWDSCALE_MAX] 36 #define DA9063_WDG_TIMEOUT wdt_timeout[3] 37 #define DA9063_RESET_PROTECTION_MS 256 38 39 struct da9063_watchdog { 40 struct da9063 *da9063; 41 struct watchdog_device wdtdev; 42 }; 43 44 static unsigned int da9063_wdt_timeout_to_sel(unsigned int secs) 45 { 46 unsigned int i; 47 48 for (i = DA9063_TWDSCALE_MIN; i <= DA9063_TWDSCALE_MAX; i++) { 49 if (wdt_timeout[i] >= secs) 50 return i; 51 } 52 53 return DA9063_TWDSCALE_MAX; 54 } 55 56 static int _da9063_wdt_set_timeout(struct da9063 *da9063, unsigned int regval) 57 { 58 return regmap_update_bits(da9063->regmap, DA9063_REG_CONTROL_D, 59 DA9063_TWDSCALE_MASK, regval); 60 } 61 62 static int da9063_wdt_start(struct watchdog_device *wdd) 63 { 64 struct da9063_watchdog *wdt = watchdog_get_drvdata(wdd); 65 unsigned int selector; 66 int ret; 67 68 selector = da9063_wdt_timeout_to_sel(wdt->wdtdev.timeout); 69 ret = _da9063_wdt_set_timeout(wdt->da9063, selector); 70 if (ret) 71 dev_err(wdt->da9063->dev, "Watchdog failed to start (err = %d)\n", 72 ret); 73 74 return ret; 75 } 76 77 static int da9063_wdt_stop(struct watchdog_device *wdd) 78 { 79 struct da9063_watchdog *wdt = watchdog_get_drvdata(wdd); 80 int ret; 81 82 ret = regmap_update_bits(wdt->da9063->regmap, DA9063_REG_CONTROL_D, 83 DA9063_TWDSCALE_MASK, DA9063_TWDSCALE_DISABLE); 84 if (ret) 85 dev_alert(wdt->da9063->dev, "Watchdog failed to stop (err = %d)\n", 86 ret); 87 88 return ret; 89 } 90 91 static int da9063_wdt_ping(struct watchdog_device *wdd) 92 { 93 struct da9063_watchdog *wdt = watchdog_get_drvdata(wdd); 94 int ret; 95 96 ret = regmap_write(wdt->da9063->regmap, DA9063_REG_CONTROL_F, 97 DA9063_WATCHDOG); 98 if (ret) 99 dev_alert(wdt->da9063->dev, "Failed to ping the watchdog (err = %d)\n", 100 ret); 101 102 return ret; 103 } 104 105 static int da9063_wdt_set_timeout(struct watchdog_device *wdd, 106 unsigned int timeout) 107 { 108 struct da9063_watchdog *wdt = watchdog_get_drvdata(wdd); 109 unsigned int selector; 110 int ret; 111 112 selector = da9063_wdt_timeout_to_sel(timeout); 113 ret = _da9063_wdt_set_timeout(wdt->da9063, selector); 114 if (ret) 115 dev_err(wdt->da9063->dev, "Failed to set watchdog timeout (err = %d)\n", 116 ret); 117 else 118 wdd->timeout = wdt_timeout[selector]; 119 120 return ret; 121 } 122 123 static int da9063_wdt_restart(struct watchdog_device *wdd, unsigned long action, 124 void *data) 125 { 126 struct da9063_watchdog *wdt = watchdog_get_drvdata(wdd); 127 int ret; 128 129 ret = regmap_write(wdt->da9063->regmap, DA9063_REG_CONTROL_F, 130 DA9063_SHUTDOWN); 131 if (ret) 132 dev_alert(wdt->da9063->dev, "Failed to shutdown (err = %d)\n", 133 ret); 134 135 return ret; 136 } 137 138 static const struct watchdog_info da9063_watchdog_info = { 139 .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING, 140 .identity = "DA9063 Watchdog", 141 }; 142 143 static const struct watchdog_ops da9063_watchdog_ops = { 144 .owner = THIS_MODULE, 145 .start = da9063_wdt_start, 146 .stop = da9063_wdt_stop, 147 .ping = da9063_wdt_ping, 148 .set_timeout = da9063_wdt_set_timeout, 149 .restart = da9063_wdt_restart, 150 }; 151 152 static int da9063_wdt_probe(struct platform_device *pdev) 153 { 154 struct da9063 *da9063; 155 struct da9063_watchdog *wdt; 156 157 if (!pdev->dev.parent) 158 return -EINVAL; 159 160 da9063 = dev_get_drvdata(pdev->dev.parent); 161 if (!da9063) 162 return -EINVAL; 163 164 wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL); 165 if (!wdt) 166 return -ENOMEM; 167 168 wdt->da9063 = da9063; 169 170 wdt->wdtdev.info = &da9063_watchdog_info; 171 wdt->wdtdev.ops = &da9063_watchdog_ops; 172 wdt->wdtdev.min_timeout = DA9063_WDT_MIN_TIMEOUT; 173 wdt->wdtdev.max_timeout = DA9063_WDT_MAX_TIMEOUT; 174 wdt->wdtdev.min_hw_heartbeat_ms = DA9063_RESET_PROTECTION_MS; 175 wdt->wdtdev.timeout = DA9063_WDG_TIMEOUT; 176 wdt->wdtdev.parent = &pdev->dev; 177 178 wdt->wdtdev.status = WATCHDOG_NOWAYOUT_INIT_STATUS; 179 180 watchdog_set_restart_priority(&wdt->wdtdev, 128); 181 182 watchdog_set_drvdata(&wdt->wdtdev, wdt); 183 184 return devm_watchdog_register_device(&pdev->dev, &wdt->wdtdev); 185 } 186 187 static struct platform_driver da9063_wdt_driver = { 188 .probe = da9063_wdt_probe, 189 .driver = { 190 .name = DA9063_DRVNAME_WATCHDOG, 191 }, 192 }; 193 module_platform_driver(da9063_wdt_driver); 194 195 MODULE_AUTHOR("Mariusz Wojtasik <mariusz.wojtasik@diasemi.com>"); 196 MODULE_DESCRIPTION("Watchdog driver for Dialog DA9063"); 197 MODULE_LICENSE("GPL"); 198 MODULE_ALIAS("platform:" DA9063_DRVNAME_WATCHDOG); 199