/* * Watchdog driver for DA9063 PMICs. * * Copyright(c) 2012 Dialog Semiconductor Ltd. * * Author: Mariusz Wojtasik <mariusz.wojtasik@diasemi.com> * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License as published by the * Free Software Foundation; either version 2 of the License, or (at your * option) any later version. */ #include <linux/kernel.h> #include <linux/module.h> #include <linux/watchdog.h> #include <linux/platform_device.h> #include <linux/uaccess.h> #include <linux/slab.h> #include <linux/delay.h> #include <linux/mfd/da9063/registers.h> #include <linux/mfd/da9063/core.h> #include <linux/reboot.h> #include <linux/regmap.h> /* * 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] struct da9063_watchdog { struct da9063 *da9063; struct watchdog_device wdtdev; struct notifier_block restart_handler; }; 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; } static int _da9063_wdt_set_timeout(struct da9063 *da9063, unsigned int regval) { 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_watchdog *wdt = watchdog_get_drvdata(wdd); unsigned int selector; int ret; selector = da9063_wdt_timeout_to_sel(wdt->wdtdev.timeout); ret = _da9063_wdt_set_timeout(wdt->da9063, selector); if (ret) dev_err(wdt->da9063->dev, "Watchdog failed to start (err = %d)\n", ret); return ret; } static int da9063_wdt_stop(struct watchdog_device *wdd) { struct da9063_watchdog *wdt = watchdog_get_drvdata(wdd); int ret; ret = regmap_update_bits(wdt->da9063->regmap, DA9063_REG_CONTROL_D, DA9063_TWDSCALE_MASK, DA9063_TWDSCALE_DISABLE); if (ret) dev_alert(wdt->da9063->dev, "Watchdog failed to stop (err = %d)\n", ret); return ret; } static int da9063_wdt_ping(struct watchdog_device *wdd) { struct da9063_watchdog *wdt = watchdog_get_drvdata(wdd); int ret; ret = regmap_write(wdt->da9063->regmap, DA9063_REG_CONTROL_F, DA9063_WATCHDOG); if (ret) dev_alert(wdt->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_watchdog *wdt = watchdog_get_drvdata(wdd); unsigned int selector; int ret; selector = da9063_wdt_timeout_to_sel(timeout); ret = _da9063_wdt_set_timeout(wdt->da9063, selector); if (ret) dev_err(wdt->da9063->dev, "Failed to set watchdog timeout (err = %d)\n", ret); else wdd->timeout = wdt_timeout[selector]; return ret; } static int da9063_wdt_restart_handler(struct notifier_block *this, unsigned long mode, void *cmd) { struct da9063_watchdog *wdt = container_of(this, struct da9063_watchdog, restart_handler); int ret; ret = regmap_write(wdt->da9063->regmap, DA9063_REG_CONTROL_F, DA9063_SHUTDOWN); if (ret) dev_alert(wdt->da9063->dev, "Failed to shutdown (err = %d)\n", ret); return NOTIFY_DONE; } 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, }; static int da9063_wdt_probe(struct platform_device *pdev) { int ret; struct da9063 *da9063; struct da9063_watchdog *wdt; if (!pdev->dev.parent) return -EINVAL; da9063 = dev_get_drvdata(pdev->dev.parent); if (!da9063) return -EINVAL; wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL); if (!wdt) return -ENOMEM; wdt->da9063 = da9063; wdt->wdtdev.info = &da9063_watchdog_info; wdt->wdtdev.ops = &da9063_watchdog_ops; wdt->wdtdev.min_timeout = DA9063_WDT_MIN_TIMEOUT; wdt->wdtdev.max_timeout = DA9063_WDT_MAX_TIMEOUT; wdt->wdtdev.timeout = DA9063_WDG_TIMEOUT; wdt->wdtdev.status = WATCHDOG_NOWAYOUT_INIT_STATUS; watchdog_set_drvdata(&wdt->wdtdev, wdt); dev_set_drvdata(&pdev->dev, wdt); ret = watchdog_register_device(&wdt->wdtdev); if (ret) return ret; wdt->restart_handler.notifier_call = da9063_wdt_restart_handler; wdt->restart_handler.priority = 128; ret = register_restart_handler(&wdt->restart_handler); if (ret) dev_err(wdt->da9063->dev, "Failed to register restart handler (err = %d)\n", ret); return 0; } static int da9063_wdt_remove(struct platform_device *pdev) { struct da9063_watchdog *wdt = dev_get_drvdata(&pdev->dev); unregister_restart_handler(&wdt->restart_handler); watchdog_unregister_device(&wdt->wdtdev); return 0; } static struct platform_driver da9063_wdt_driver = { .probe = da9063_wdt_probe, .remove = da9063_wdt_remove, .driver = { .name = DA9063_DRVNAME_WATCHDOG, }, }; module_platform_driver(da9063_wdt_driver); MODULE_AUTHOR("Mariusz Wojtasik <mariusz.wojtasik@diasemi.com>"); MODULE_DESCRIPTION("Watchdog driver for Dialog DA9063"); MODULE_LICENSE("GPL"); MODULE_ALIAS("platform:" DA9063_DRVNAME_WATCHDOG);