/* * Watchdog driver for Ricoh RN5T618 PMIC * * Copyright (C) 2014 Beniamino Galvani <b.galvani@gmail.com> * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * version 2 as published by the Free Software Foundation. * * You should have received a copy of the GNU General Public License * along with this program. If not, see <http://www.gnu.org/licenses/>. */ #include <linux/device.h> #include <linux/mfd/rn5t618.h> #include <linux/module.h> #include <linux/platform_device.h> #include <linux/watchdog.h> #define DRIVER_NAME "rn5t618-wdt" static bool nowayout = WATCHDOG_NOWAYOUT; static unsigned int timeout; module_param(timeout, uint, 0); MODULE_PARM_DESC(timeout, "Initial watchdog timeout in seconds"); module_param(nowayout, bool, 0); MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); struct rn5t618_wdt { struct watchdog_device wdt_dev; struct rn5t618 *rn5t618; }; /* * This array encodes the values of WDOGTIM field for the supported * watchdog expiration times. If the watchdog is not accessed before * the timer expiration, the PMU generates an interrupt and if the CPU * doesn't clear it within one second the system is restarted. */ static const struct { u8 reg_val; unsigned int time; } rn5t618_wdt_map[] = { { 0, 1 }, { 1, 8 }, { 2, 32 }, { 3, 128 }, }; static int rn5t618_wdt_set_timeout(struct watchdog_device *wdt_dev, unsigned int t) { struct rn5t618_wdt *wdt = watchdog_get_drvdata(wdt_dev); int ret, i; for (i = 0; i < ARRAY_SIZE(rn5t618_wdt_map); i++) { if (rn5t618_wdt_map[i].time + 1 >= t) break; } if (i == ARRAY_SIZE(rn5t618_wdt_map)) return -EINVAL; ret = regmap_update_bits(wdt->rn5t618->regmap, RN5T618_WATCHDOG, RN5T618_WATCHDOG_WDOGTIM_M, rn5t618_wdt_map[i].reg_val); if (!ret) wdt_dev->timeout = rn5t618_wdt_map[i].time; return ret; } static int rn5t618_wdt_start(struct watchdog_device *wdt_dev) { struct rn5t618_wdt *wdt = watchdog_get_drvdata(wdt_dev); int ret; ret = rn5t618_wdt_set_timeout(wdt_dev, wdt_dev->timeout); if (ret) return ret; /* enable repower-on */ ret = regmap_update_bits(wdt->rn5t618->regmap, RN5T618_REPCNT, RN5T618_REPCNT_REPWRON, RN5T618_REPCNT_REPWRON); if (ret) return ret; /* enable watchdog */ ret = regmap_update_bits(wdt->rn5t618->regmap, RN5T618_WATCHDOG, RN5T618_WATCHDOG_WDOGEN, RN5T618_WATCHDOG_WDOGEN); if (ret) return ret; /* enable watchdog interrupt */ return regmap_update_bits(wdt->rn5t618->regmap, RN5T618_PWRIREN, RN5T618_PWRIRQ_IR_WDOG, RN5T618_PWRIRQ_IR_WDOG); } static int rn5t618_wdt_stop(struct watchdog_device *wdt_dev) { struct rn5t618_wdt *wdt = watchdog_get_drvdata(wdt_dev); return regmap_update_bits(wdt->rn5t618->regmap, RN5T618_WATCHDOG, RN5T618_WATCHDOG_WDOGEN, 0); } static int rn5t618_wdt_ping(struct watchdog_device *wdt_dev) { struct rn5t618_wdt *wdt = watchdog_get_drvdata(wdt_dev); unsigned int val; int ret; /* The counter is restarted after a R/W access to watchdog register */ ret = regmap_read(wdt->rn5t618->regmap, RN5T618_WATCHDOG, &val); if (ret) return ret; ret = regmap_write(wdt->rn5t618->regmap, RN5T618_WATCHDOG, val); if (ret) return ret; /* Clear pending watchdog interrupt */ return regmap_update_bits(wdt->rn5t618->regmap, RN5T618_PWRIRQ, RN5T618_PWRIRQ_IR_WDOG, 0); } static struct watchdog_info rn5t618_wdt_info = { .options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING, .identity = DRIVER_NAME, }; static const struct watchdog_ops rn5t618_wdt_ops = { .owner = THIS_MODULE, .start = rn5t618_wdt_start, .stop = rn5t618_wdt_stop, .ping = rn5t618_wdt_ping, .set_timeout = rn5t618_wdt_set_timeout, }; static int rn5t618_wdt_probe(struct platform_device *pdev) { struct rn5t618 *rn5t618 = dev_get_drvdata(pdev->dev.parent); struct rn5t618_wdt *wdt; int min_timeout, max_timeout; wdt = devm_kzalloc(&pdev->dev, sizeof(struct rn5t618_wdt), GFP_KERNEL); if (!wdt) return -ENOMEM; min_timeout = rn5t618_wdt_map[0].time; max_timeout = rn5t618_wdt_map[ARRAY_SIZE(rn5t618_wdt_map) - 1].time; wdt->rn5t618 = rn5t618; wdt->wdt_dev.info = &rn5t618_wdt_info; wdt->wdt_dev.ops = &rn5t618_wdt_ops; wdt->wdt_dev.min_timeout = min_timeout; wdt->wdt_dev.max_timeout = max_timeout; wdt->wdt_dev.timeout = max_timeout; wdt->wdt_dev.parent = &pdev->dev; watchdog_set_drvdata(&wdt->wdt_dev, wdt); watchdog_init_timeout(&wdt->wdt_dev, timeout, &pdev->dev); watchdog_set_nowayout(&wdt->wdt_dev, nowayout); platform_set_drvdata(pdev, wdt); return watchdog_register_device(&wdt->wdt_dev); } static int rn5t618_wdt_remove(struct platform_device *pdev) { struct rn5t618_wdt *wdt = platform_get_drvdata(pdev); watchdog_unregister_device(&wdt->wdt_dev); return 0; } static struct platform_driver rn5t618_wdt_driver = { .probe = rn5t618_wdt_probe, .remove = rn5t618_wdt_remove, .driver = { .name = DRIVER_NAME, }, }; module_platform_driver(rn5t618_wdt_driver); MODULE_AUTHOR("Beniamino Galvani <b.galvani@gmail.com>"); MODULE_DESCRIPTION("RN5T618 watchdog driver"); MODULE_LICENSE("GPL v2");