/* * System monitoring driver for DA9052 PMICs. * * Copyright(c) 2012 Dialog Semiconductor Ltd. * * Author: Anthony Olech <Anthony.Olech@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/module.h> #include <linux/delay.h> #include <linux/uaccess.h> #include <linux/platform_device.h> #include <linux/time.h> #include <linux/watchdog.h> #include <linux/types.h> #include <linux/kernel.h> #include <linux/jiffies.h> #include <linux/mfd/da9052/reg.h> #include <linux/mfd/da9052/da9052.h> #define DA9052_DEF_TIMEOUT 4 #define DA9052_TWDMIN 256 struct da9052_wdt_data { struct watchdog_device wdt; struct da9052 *da9052; unsigned long jpast; }; static const struct { u8 reg_val; int time; /* Seconds */ } da9052_wdt_maps[] = { { 1, 2 }, { 2, 4 }, { 3, 8 }, { 4, 16 }, { 5, 32 }, { 5, 33 }, /* Actual time 32.768s so included both 32s and 33s */ { 6, 65 }, { 6, 66 }, /* Actual time 65.536s so include both, 65s and 66s */ { 7, 131 }, }; static int da9052_wdt_set_timeout(struct watchdog_device *wdt_dev, unsigned int timeout) { struct da9052_wdt_data *driver_data = watchdog_get_drvdata(wdt_dev); struct da9052 *da9052 = driver_data->da9052; int ret, i; /* * Disable the Watchdog timer before setting * new time out. */ ret = da9052_reg_update(da9052, DA9052_CONTROL_D_REG, DA9052_CONTROLD_TWDSCALE, 0); if (ret < 0) { dev_err(da9052->dev, "Failed to disable watchdog bit, %d\n", ret); return ret; } if (timeout) { /* * To change the timeout, da9052 needs to * be disabled for at least 150 us. */ udelay(150); /* Set the desired timeout */ for (i = 0; i < ARRAY_SIZE(da9052_wdt_maps); i++) if (da9052_wdt_maps[i].time == timeout) break; if (i == ARRAY_SIZE(da9052_wdt_maps)) ret = -EINVAL; else ret = da9052_reg_update(da9052, DA9052_CONTROL_D_REG, DA9052_CONTROLD_TWDSCALE, da9052_wdt_maps[i].reg_val); if (ret < 0) { dev_err(da9052->dev, "Failed to update timescale bit, %d\n", ret); return ret; } wdt_dev->timeout = timeout; driver_data->jpast = jiffies; } return 0; } static int da9052_wdt_start(struct watchdog_device *wdt_dev) { return da9052_wdt_set_timeout(wdt_dev, wdt_dev->timeout); } static int da9052_wdt_stop(struct watchdog_device *wdt_dev) { return da9052_wdt_set_timeout(wdt_dev, 0); } static int da9052_wdt_ping(struct watchdog_device *wdt_dev) { struct da9052_wdt_data *driver_data = watchdog_get_drvdata(wdt_dev); struct da9052 *da9052 = driver_data->da9052; unsigned long msec, jnow = jiffies; int ret; /* * We have a minimum time for watchdog window called TWDMIN. A write * to the watchdog before this elapsed time should cause an error. */ msec = (jnow - driver_data->jpast) * 1000/HZ; if (msec < DA9052_TWDMIN) mdelay(msec); /* Reset the watchdog timer */ ret = da9052_reg_update(da9052, DA9052_CONTROL_D_REG, DA9052_CONTROLD_WATCHDOG, 1 << 7); if (ret < 0) goto err_strobe; /* * FIXME: Reset the watchdog core, in general PMIC * is supposed to do this */ ret = da9052_reg_update(da9052, DA9052_CONTROL_D_REG, DA9052_CONTROLD_WATCHDOG, 0 << 7); err_strobe: return ret; } static struct watchdog_info da9052_wdt_info = { .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING, .identity = "DA9052 Watchdog", }; static const struct watchdog_ops da9052_wdt_ops = { .owner = THIS_MODULE, .start = da9052_wdt_start, .stop = da9052_wdt_stop, .ping = da9052_wdt_ping, .set_timeout = da9052_wdt_set_timeout, }; static int da9052_wdt_probe(struct platform_device *pdev) { struct da9052 *da9052 = dev_get_drvdata(pdev->dev.parent); struct da9052_wdt_data *driver_data; struct watchdog_device *da9052_wdt; int ret; driver_data = devm_kzalloc(&pdev->dev, sizeof(*driver_data), GFP_KERNEL); if (!driver_data) { ret = -ENOMEM; goto err; } driver_data->da9052 = da9052; da9052_wdt = &driver_data->wdt; da9052_wdt->timeout = DA9052_DEF_TIMEOUT; da9052_wdt->info = &da9052_wdt_info; da9052_wdt->ops = &da9052_wdt_ops; da9052_wdt->parent = &pdev->dev; watchdog_set_drvdata(da9052_wdt, driver_data); ret = da9052_reg_update(da9052, DA9052_CONTROL_D_REG, DA9052_CONTROLD_TWDSCALE, 0); if (ret < 0) { dev_err(&pdev->dev, "Failed to disable watchdog bits, %d\n", ret); goto err; } ret = watchdog_register_device(&driver_data->wdt); if (ret != 0) { dev_err(da9052->dev, "watchdog_register_device() failed: %d\n", ret); goto err; } platform_set_drvdata(pdev, driver_data); err: return ret; } static int da9052_wdt_remove(struct platform_device *pdev) { struct da9052_wdt_data *driver_data = platform_get_drvdata(pdev); watchdog_unregister_device(&driver_data->wdt); return 0; } static struct platform_driver da9052_wdt_driver = { .probe = da9052_wdt_probe, .remove = da9052_wdt_remove, .driver = { .name = "da9052-watchdog", }, }; module_platform_driver(da9052_wdt_driver); MODULE_AUTHOR("Anthony Olech <Anthony.Olech@diasemi.com>"); MODULE_DESCRIPTION("DA9052 SM Device Driver"); MODULE_LICENSE("GPL"); MODULE_ALIAS("platform:da9052-watchdog");