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 38 struct da9063_watchdog { 39 struct da9063 *da9063; 40 struct watchdog_device wdtdev; 41 }; 42 43 static unsigned int da9063_wdt_timeout_to_sel(unsigned int secs) 44 { 45 unsigned int i; 46 47 for (i = DA9063_TWDSCALE_MIN; i <= DA9063_TWDSCALE_MAX; i++) { 48 if (wdt_timeout[i] >= secs) 49 return i; 50 } 51 52 return DA9063_TWDSCALE_MAX; 53 } 54 55 static int _da9063_wdt_set_timeout(struct da9063 *da9063, unsigned int regval) 56 { 57 return regmap_update_bits(da9063->regmap, DA9063_REG_CONTROL_D, 58 DA9063_TWDSCALE_MASK, regval); 59 } 60 61 static int da9063_wdt_start(struct watchdog_device *wdd) 62 { 63 struct da9063_watchdog *wdt = watchdog_get_drvdata(wdd); 64 unsigned int selector; 65 int ret; 66 67 selector = da9063_wdt_timeout_to_sel(wdt->wdtdev.timeout); 68 ret = _da9063_wdt_set_timeout(wdt->da9063, selector); 69 if (ret) 70 dev_err(wdt->da9063->dev, "Watchdog failed to start (err = %d)\n", 71 ret); 72 73 return ret; 74 } 75 76 static int da9063_wdt_stop(struct watchdog_device *wdd) 77 { 78 struct da9063_watchdog *wdt = watchdog_get_drvdata(wdd); 79 int ret; 80 81 ret = regmap_update_bits(wdt->da9063->regmap, DA9063_REG_CONTROL_D, 82 DA9063_TWDSCALE_MASK, DA9063_TWDSCALE_DISABLE); 83 if (ret) 84 dev_alert(wdt->da9063->dev, "Watchdog failed to stop (err = %d)\n", 85 ret); 86 87 return ret; 88 } 89 90 static int da9063_wdt_ping(struct watchdog_device *wdd) 91 { 92 struct da9063_watchdog *wdt = watchdog_get_drvdata(wdd); 93 int ret; 94 95 ret = regmap_write(wdt->da9063->regmap, DA9063_REG_CONTROL_F, 96 DA9063_WATCHDOG); 97 if (ret) 98 dev_alert(wdt->da9063->dev, "Failed to ping the watchdog (err = %d)\n", 99 ret); 100 101 return ret; 102 } 103 104 static int da9063_wdt_set_timeout(struct watchdog_device *wdd, 105 unsigned int timeout) 106 { 107 struct da9063_watchdog *wdt = watchdog_get_drvdata(wdd); 108 unsigned int selector; 109 int ret; 110 111 selector = da9063_wdt_timeout_to_sel(timeout); 112 ret = _da9063_wdt_set_timeout(wdt->da9063, selector); 113 if (ret) 114 dev_err(wdt->da9063->dev, "Failed to set watchdog timeout (err = %d)\n", 115 ret); 116 else 117 wdd->timeout = wdt_timeout[selector]; 118 119 return ret; 120 } 121 122 static const struct watchdog_info da9063_watchdog_info = { 123 .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING, 124 .identity = "DA9063 Watchdog", 125 }; 126 127 static const struct watchdog_ops da9063_watchdog_ops = { 128 .owner = THIS_MODULE, 129 .start = da9063_wdt_start, 130 .stop = da9063_wdt_stop, 131 .ping = da9063_wdt_ping, 132 .set_timeout = da9063_wdt_set_timeout, 133 }; 134 135 static int da9063_wdt_probe(struct platform_device *pdev) 136 { 137 int ret; 138 struct da9063 *da9063; 139 struct da9063_watchdog *wdt; 140 141 if (!pdev->dev.parent) 142 return -EINVAL; 143 144 da9063 = dev_get_drvdata(pdev->dev.parent); 145 if (!da9063) 146 return -EINVAL; 147 148 wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL); 149 if (!wdt) 150 return -ENOMEM; 151 152 wdt->da9063 = da9063; 153 154 wdt->wdtdev.info = &da9063_watchdog_info; 155 wdt->wdtdev.ops = &da9063_watchdog_ops; 156 wdt->wdtdev.min_timeout = DA9063_WDT_MIN_TIMEOUT; 157 wdt->wdtdev.max_timeout = DA9063_WDT_MAX_TIMEOUT; 158 wdt->wdtdev.timeout = DA9063_WDG_TIMEOUT; 159 160 wdt->wdtdev.status = WATCHDOG_NOWAYOUT_INIT_STATUS; 161 162 watchdog_set_drvdata(&wdt->wdtdev, wdt); 163 dev_set_drvdata(&pdev->dev, wdt); 164 165 ret = watchdog_register_device(&wdt->wdtdev); 166 167 return ret; 168 } 169 170 static int da9063_wdt_remove(struct platform_device *pdev) 171 { 172 struct da9063_watchdog *wdt = dev_get_drvdata(&pdev->dev); 173 174 watchdog_unregister_device(&wdt->wdtdev); 175 176 return 0; 177 } 178 179 static struct platform_driver da9063_wdt_driver = { 180 .probe = da9063_wdt_probe, 181 .remove = da9063_wdt_remove, 182 .driver = { 183 .name = DA9063_DRVNAME_WATCHDOG, 184 }, 185 }; 186 module_platform_driver(da9063_wdt_driver); 187 188 MODULE_AUTHOR("Mariusz Wojtasik <mariusz.wojtasik@diasemi.com>"); 189 MODULE_DESCRIPTION("Watchdog driver for Dialog DA9063"); 190 MODULE_LICENSE("GPL"); 191 MODULE_ALIAS("platform:" DA9063_DRVNAME_WATCHDOG); 192