diff options
Diffstat (limited to 'drivers/watchdog/da9063_wdt.c')
| -rw-r--r-- | drivers/watchdog/da9063_wdt.c | 191 |
1 files changed, 191 insertions, 0 deletions
diff --git a/drivers/watchdog/da9063_wdt.c b/drivers/watchdog/da9063_wdt.c new file mode 100644 index 0000000..2cd6b2c --- /dev/null +++ b/drivers/watchdog/da9063_wdt.c @@ -0,0 +1,191 @@ +/* + * 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/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; +}; + +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 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); + + return ret; +} + +static int da9063_wdt_remove(struct platform_device *pdev) +{ + struct da9063_watchdog *wdt = dev_get_drvdata(&pdev->dev); + + 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); |
