diff options
Diffstat (limited to 'drivers/watchdog/stpmic1_wdt.c')
| -rw-r--r-- | drivers/watchdog/stpmic1_wdt.c | 140 |
1 files changed, 140 insertions, 0 deletions
diff --git a/drivers/watchdog/stpmic1_wdt.c b/drivers/watchdog/stpmic1_wdt.c new file mode 100644 index 000000000..45d0c5434 --- /dev/null +++ b/drivers/watchdog/stpmic1_wdt.c @@ -0,0 +1,140 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (C) STMicroelectronics 2018 +// Author: Pascal Paillet <p.paillet@st.com> for STMicroelectronics. + +#include <linux/kernel.h> +#include <linux/mfd/stpmic1.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/of.h> +#include <linux/regmap.h> +#include <linux/slab.h> +#include <linux/watchdog.h> + +/* WATCHDOG CONTROL REGISTER bit */ +#define WDT_START BIT(0) +#define WDT_PING BIT(1) +#define WDT_START_MASK BIT(0) +#define WDT_PING_MASK BIT(1) +#define WDT_STOP 0 + +#define PMIC_WDT_MIN_TIMEOUT 1 +#define PMIC_WDT_MAX_TIMEOUT 256 +#define PMIC_WDT_DEFAULT_TIMEOUT 30 + +static bool nowayout = WATCHDOG_NOWAYOUT; +module_param(nowayout, bool, 0); +MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" + __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); + +struct stpmic1_wdt { + struct stpmic1 *pmic; + struct watchdog_device wdtdev; +}; + +static int pmic_wdt_start(struct watchdog_device *wdd) +{ + struct stpmic1_wdt *wdt = watchdog_get_drvdata(wdd); + + return regmap_update_bits(wdt->pmic->regmap, + WCHDG_CR, WDT_START_MASK, WDT_START); +} + +static int pmic_wdt_stop(struct watchdog_device *wdd) +{ + struct stpmic1_wdt *wdt = watchdog_get_drvdata(wdd); + + return regmap_update_bits(wdt->pmic->regmap, + WCHDG_CR, WDT_START_MASK, WDT_STOP); +} + +static int pmic_wdt_ping(struct watchdog_device *wdd) +{ + struct stpmic1_wdt *wdt = watchdog_get_drvdata(wdd); + + return regmap_update_bits(wdt->pmic->regmap, + WCHDG_CR, WDT_PING_MASK, WDT_PING); +} + +static int pmic_wdt_set_timeout(struct watchdog_device *wdd, + unsigned int timeout) +{ + struct stpmic1_wdt *wdt = watchdog_get_drvdata(wdd); + + wdd->timeout = timeout; + /* timeout is equal to register value + 1 */ + return regmap_write(wdt->pmic->regmap, WCHDG_TIMER_CR, timeout - 1); +} + +static const struct watchdog_info pmic_watchdog_info = { + .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE, + .identity = "STPMIC1 PMIC Watchdog", +}; + +static const struct watchdog_ops pmic_watchdog_ops = { + .owner = THIS_MODULE, + .start = pmic_wdt_start, + .stop = pmic_wdt_stop, + .ping = pmic_wdt_ping, + .set_timeout = pmic_wdt_set_timeout, +}; + +static int pmic_wdt_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + int ret; + struct stpmic1 *pmic; + struct stpmic1_wdt *wdt; + + if (!dev->parent) + return -EINVAL; + + pmic = dev_get_drvdata(dev->parent); + if (!pmic) + return -EINVAL; + + wdt = devm_kzalloc(dev, sizeof(struct stpmic1_wdt), GFP_KERNEL); + if (!wdt) + return -ENOMEM; + + wdt->pmic = pmic; + + wdt->wdtdev.info = &pmic_watchdog_info; + wdt->wdtdev.ops = &pmic_watchdog_ops; + wdt->wdtdev.min_timeout = PMIC_WDT_MIN_TIMEOUT; + wdt->wdtdev.max_timeout = PMIC_WDT_MAX_TIMEOUT; + wdt->wdtdev.parent = dev; + + wdt->wdtdev.timeout = PMIC_WDT_DEFAULT_TIMEOUT; + watchdog_init_timeout(&wdt->wdtdev, 0, dev); + + watchdog_set_nowayout(&wdt->wdtdev, nowayout); + watchdog_set_drvdata(&wdt->wdtdev, wdt); + + ret = devm_watchdog_register_device(dev, &wdt->wdtdev); + if (ret) + return ret; + + dev_dbg(wdt->pmic->dev, "PMIC Watchdog driver probed\n"); + return 0; +} + +static const struct of_device_id of_pmic_wdt_match[] = { + { .compatible = "st,stpmic1-wdt" }, + { }, +}; + +MODULE_DEVICE_TABLE(of, of_pmic_wdt_match); + +static struct platform_driver stpmic1_wdt_driver = { + .probe = pmic_wdt_probe, + .driver = { + .name = "stpmic1-wdt", + .of_match_table = of_pmic_wdt_match, + }, +}; +module_platform_driver(stpmic1_wdt_driver); + +MODULE_DESCRIPTION("Watchdog driver for STPMIC1 device"); +MODULE_AUTHOR("Pascal Paillet <p.paillet@st.com>"); +MODULE_LICENSE("GPL v2"); |