// SPDX-License-Identifier: GPL-2.0+ /* * Watchdog driver for DA9063 PMICs. * * Copyright(c) 2012 Dialog Semiconductor Ltd. * * Author: Mariusz Wojtasik * */ #include #include #include #include #include #include #include #include #include #include /* * Watchdog selector to timeout in seconds. * 0: WDT disabled; * others: timeout = 2048 ms * 2^(TWDSCALE-1). */ static const unsigned int wdt_timeout[] = { 0, 2, 4, 8, 16, 32, 65, 131 }; #define DA9063_TWDSCALE_DISABLE 0 #define DA9063_TWDSCALE_MIN 1 #define DA9063_TWDSCALE_MAX (ARRAY_SIZE(wdt_timeout) - 1) #define DA9063_WDT_MIN_TIMEOUT wdt_timeout[DA9063_TWDSCALE_MIN] #define DA9063_WDT_MAX_TIMEOUT wdt_timeout[DA9063_TWDSCALE_MAX] #define DA9063_WDG_TIMEOUT wdt_timeout[3] #define DA9063_RESET_PROTECTION_MS 256 static unsigned int da9063_wdt_timeout_to_sel(unsigned int secs) { unsigned int i; for (i = DA9063_TWDSCALE_MIN; i <= DA9063_TWDSCALE_MAX; i++) { if (wdt_timeout[i] >= secs) return i; } return DA9063_TWDSCALE_MAX; } /* * Return 0 if watchdog is disabled, else non zero. */ static unsigned int da9063_wdt_is_running(struct da9063 *da9063) { unsigned int val; regmap_read(da9063->regmap, DA9063_REG_CONTROL_D, &val); return val & DA9063_TWDSCALE_MASK; } static int da9063_wdt_disable_timer(struct da9063 *da9063) { return regmap_update_bits(da9063->regmap, DA9063_REG_CONTROL_D, DA9063_TWDSCALE_MASK, DA9063_TWDSCALE_DISABLE); } static int da9063_wdt_update_timeout(struct da9063 *da9063, unsigned int timeout) { unsigned int regval; int ret; /* * The watchdog triggers a reboot if a timeout value is already * programmed because the timeout value combines two functions * in one: indicating the counter limit and starting the watchdog. * The watchdog must be disabled to be able to change the timeout * value if the watchdog is already running. Then we can set the * new timeout value which enables the watchdog again. */ ret = da9063_wdt_disable_timer(da9063); if (ret) return ret; usleep_range(150, 300); regval = da9063_wdt_timeout_to_sel(timeout); return regmap_update_bits(da9063->regmap, DA9063_REG_CONTROL_D, DA9063_TWDSCALE_MASK, regval); } static int da9063_wdt_start(struct watchdog_device *wdd) { struct da9063 *da9063 = watchdog_get_drvdata(wdd); int ret; ret = da9063_wdt_update_timeout(da9063, wdd->timeout); if (ret) dev_err(da9063->dev, "Watchdog failed to start (err = %d)\n", ret); return ret; } static int da9063_wdt_stop(struct watchdog_device *wdd) { struct da9063 *da9063 = watchdog_get_drvdata(wdd); int ret; ret = da9063_wdt_disable_timer(da9063); if (ret) dev_alert(da9063->dev, "Watchdog failed to stop (err = %d)\n", ret); return ret; } static int da9063_wdt_ping(struct watchdog_device *wdd) { struct da9063 *da9063 = watchdog_get_drvdata(wdd); int ret; ret = regmap_write(da9063->regmap, DA9063_REG_CONTROL_F, DA9063_WATCHDOG); if (ret) dev_alert(da9063->dev, "Failed to ping the watchdog (err = %d)\n", ret); return ret; } static int da9063_wdt_set_timeout(struct watchdog_device *wdd, unsigned int timeout) { struct da9063 *da9063 = watchdog_get_drvdata(wdd); int ret = 0; /* * There are two cases when a set_timeout() will be called: * 1. The watchdog is off and someone wants to set the timeout for the * further use. * 2. The watchdog is already running and a new timeout value should be * set. * * The watchdog can't store a timeout value not equal zero without * enabling the watchdog, so the timeout must be buffered by the driver. */ if (watchdog_active(wdd)) ret = da9063_wdt_update_timeout(da9063, timeout); if (ret) dev_err(da9063->dev, "Failed to set watchdog timeout (err = %d)\n", ret); else wdd->timeout = wdt_timeout[da9063_wdt_timeout_to_sel(timeout)]; return ret; } static int da9063_wdt_restart(struct watchdog_device *wdd, unsigned long action, void *data) { struct da9063 *da9063 = watchdog_get_drvdata(wdd); int ret; ret = regmap_write(da9063->regmap, DA9063_REG_CONTROL_F, DA9063_SHUTDOWN); if (ret) dev_alert(da9063->dev, "Failed to shutdown (err = %d)\n", ret); return ret; } static const struct watchdog_info da9063_watchdog_info = { .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING, .identity = "DA9063 Watchdog", }; static const struct watchdog_ops da9063_watchdog_ops = { .owner = THIS_MODULE, .start = da9063_wdt_start, .stop = da9063_wdt_stop, .ping = da9063_wdt_ping, .set_timeout = da9063_wdt_set_timeout, .restart = da9063_wdt_restart, }; static int da9063_wdt_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; struct da9063 *da9063; struct watchdog_device *wdd; if (!dev->parent) return -EINVAL; da9063 = dev_get_drvdata(dev->parent); if (!da9063) return -EINVAL; wdd = devm_kzalloc(dev, sizeof(*wdd), GFP_KERNEL); if (!wdd) return -ENOMEM; wdd->info = &da9063_watchdog_info; wdd->ops = &da9063_watchdog_ops; wdd->min_timeout = DA9063_WDT_MIN_TIMEOUT; wdd->max_timeout = DA9063_WDT_MAX_TIMEOUT; wdd->min_hw_heartbeat_ms = DA9063_RESET_PROTECTION_MS; wdd->timeout = DA9063_WDG_TIMEOUT; wdd->parent = dev; wdd->status = WATCHDOG_NOWAYOUT_INIT_STATUS; watchdog_set_restart_priority(wdd, 128); watchdog_set_drvdata(wdd, da9063); /* Change the timeout to the default value if the watchdog is running */ if (da9063_wdt_is_running(da9063)) { da9063_wdt_update_timeout(da9063, DA9063_WDG_TIMEOUT); set_bit(WDOG_HW_RUNNING, &wdd->status); } return devm_watchdog_register_device(dev, wdd); } static struct platform_driver da9063_wdt_driver = { .probe = da9063_wdt_probe, .driver = { .name = DA9063_DRVNAME_WATCHDOG, }, }; module_platform_driver(da9063_wdt_driver); MODULE_AUTHOR("Mariusz Wojtasik "); MODULE_DESCRIPTION("Watchdog driver for Dialog DA9063"); MODULE_LICENSE("GPL"); MODULE_ALIAS("platform:" DA9063_DRVNAME_WATCHDOG);