diff options
| -rw-r--r-- | drivers/watchdog/Kconfig | 12 | ||||
| -rw-r--r-- | drivers/watchdog/Makefile | 1 | ||||
| -rw-r--r-- | drivers/watchdog/bd70528_wdt.c | 290 |
3 files changed, 303 insertions, 0 deletions
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig index fa325b49672e..4735279bdae9 100644 --- a/drivers/watchdog/Kconfig +++ b/drivers/watchdog/Kconfig @@ -90,6 +90,18 @@ config SOFT_WATCHDOG_PRETIMEOUT watchdog. Be aware that governors might affect the watchdog because it is purely software, e.g. the panic governor will stall it! +config BD70528_WATCHDOG + tristate "ROHM BD70528 PMIC Watchdog" + depends on MFD_ROHM_BD70528 + select WATCHDOG_CORE + help + Support for the watchdog in the ROHM BD70528 PMIC. Watchdog trigger + cause system reset. + + Say Y here to include support for the ROHM BD70528 watchdog. + Alternatively say M to compile the driver as a module, + which will be called bd70528_wdt. + config DA9052_WATCHDOG tristate "Dialog DA9052 Watchdog" depends on PMIC_DA9052 || COMPILE_TEST diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile index ba930e464657..3985922c440a 100644 --- a/drivers/watchdog/Makefile +++ b/drivers/watchdog/Makefile @@ -205,6 +205,7 @@ obj-$(CONFIG_WATCHDOG_SUN4V) += sun4v_wdt.o obj-$(CONFIG_XEN_WDT) += xen_wdt.o # Architecture Independent +obj-$(CONFIG_BD70528_WATCHDOG) += bd70528_wdt.o obj-$(CONFIG_DA9052_WATCHDOG) += da9052_wdt.o obj-$(CONFIG_DA9055_WATCHDOG) += da9055_wdt.o obj-$(CONFIG_DA9062_WATCHDOG) += da9062_wdt.o diff --git a/drivers/watchdog/bd70528_wdt.c b/drivers/watchdog/bd70528_wdt.c new file mode 100644 index 000000000000..b0152fef4fc7 --- /dev/null +++ b/drivers/watchdog/bd70528_wdt.c @@ -0,0 +1,290 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (C) 2018 ROHM Semiconductors +// ROHM BD70528MWV watchdog driver + +#include <linux/bcd.h> +#include <linux/kernel.h> +#include <linux/mfd/rohm-bd70528.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <linux/regmap.h> +#include <linux/watchdog.h> + +/* + * Max time we can set is 1 hour, 59 minutes and 59 seconds + * and Minimum time is 1 second + */ +#define WDT_MAX_MS ((2 * 60 * 60 - 1) * 1000) +#define WDT_MIN_MS 1000 +#define DEFAULT_TIMEOUT 60 + +#define WD_CTRL_MAGIC1 0x55 +#define WD_CTRL_MAGIC2 0xAA + +struct wdtbd70528 { + struct device *dev; + struct regmap *regmap; + struct rohm_regmap_dev *mfd; + struct watchdog_device wdt; +}; + +/** + * bd70528_wdt_set - arm or disarm watchdog timer + * + * @data: device data for the PMIC instance we want to operate on + * @enable: new state of WDT. zero to disable, non zero to enable + * @old_state: previous state of WDT will be filled here + * + * Arm or disarm WDT on BD70528 PMIC. Expected to be called only by + * BD70528 RTC and BD70528 WDT drivers. The rtc_timer_lock must be taken + * by calling bd70528_wdt_lock before calling bd70528_wdt_set. + */ +int bd70528_wdt_set(struct rohm_regmap_dev *data, int enable, int *old_state) +{ + int ret, i; + unsigned int tmp; + struct bd70528_data *bd70528 = container_of(data, struct bd70528_data, + chip); + u8 wd_ctrl_arr[3] = { WD_CTRL_MAGIC1, WD_CTRL_MAGIC2, 0 }; + u8 *wd_ctrl = &wd_ctrl_arr[2]; + + ret = regmap_read(bd70528->chip.regmap, BD70528_REG_WDT_CTRL, &tmp); + if (ret) + return ret; + + *wd_ctrl = (u8)tmp; + + if (old_state) { + if (*wd_ctrl & BD70528_MASK_WDT_EN) + *old_state |= BD70528_WDT_STATE_BIT; + else + *old_state &= ~BD70528_WDT_STATE_BIT; + if ((!enable) == (!(*old_state & BD70528_WDT_STATE_BIT))) + return 0; + } + + if (enable) { + if (*wd_ctrl & BD70528_MASK_WDT_EN) + return 0; + *wd_ctrl |= BD70528_MASK_WDT_EN; + } else { + if (*wd_ctrl & BD70528_MASK_WDT_EN) + *wd_ctrl &= ~BD70528_MASK_WDT_EN; + else + return 0; + } + + for (i = 0; i < 3; i++) { + ret = regmap_write(bd70528->chip.regmap, BD70528_REG_WDT_CTRL, + wd_ctrl_arr[i]); + if (ret) + return ret; + } + + ret = regmap_read(bd70528->chip.regmap, BD70528_REG_WDT_CTRL, &tmp); + if ((tmp & BD70528_MASK_WDT_EN) != (*wd_ctrl & BD70528_MASK_WDT_EN)) { + dev_err(bd70528->chip.dev, + "Watchdog ctrl mismatch (hw) 0x%x (set) 0x%x\n", + tmp, *wd_ctrl); + ret = -EIO; + } + + return ret; +} +EXPORT_SYMBOL(bd70528_wdt_set); + +/** + * bd70528_wdt_lock - take WDT lock + * + * @bd70528: device data for the PMIC instance we want to operate on + * + * Lock WDT for arming/disarming in order to avoid race condition caused + * by WDT state changes initiated by WDT and RTC drivers. + */ +void bd70528_wdt_lock(struct rohm_regmap_dev *data) +{ + struct bd70528_data *bd70528 = container_of(data, struct bd70528_data, + chip); + + mutex_lock(&bd70528->rtc_timer_lock); +} +EXPORT_SYMBOL(bd70528_wdt_lock); + +/** + * bd70528_wdt_unlock - unlock WDT lock + * + * @bd70528: device data for the PMIC instance we want to operate on + * + * Unlock WDT lock which has previously been taken by call to + * bd70528_wdt_lock. + */ +void bd70528_wdt_unlock(struct rohm_regmap_dev *data) +{ + struct bd70528_data *bd70528 = container_of(data, struct bd70528_data, + chip); + + mutex_unlock(&bd70528->rtc_timer_lock); +} +EXPORT_SYMBOL(bd70528_wdt_unlock); + +static int bd70528_wdt_set_locked(struct wdtbd70528 *w, int enable) +{ + return bd70528_wdt_set(w->mfd, enable, NULL); +} + +static int bd70528_wdt_change(struct wdtbd70528 *w, int enable) +{ + int ret; + + bd70528_wdt_lock(w->mfd); + ret = bd70528_wdt_set_locked(w, enable); + bd70528_wdt_unlock(w->mfd); + + return ret; +} + +static int bd70528_wdt_start(struct watchdog_device *wdt) +{ + struct wdtbd70528 *w = watchdog_get_drvdata(wdt); + + dev_dbg(w->dev, "WDT ping...\n"); + return bd70528_wdt_change(w, 1); +} + +static int bd70528_wdt_stop(struct watchdog_device *wdt) +{ + struct wdtbd70528 *w = watchdog_get_drvdata(wdt); + + dev_dbg(w->dev, "WDT stopping...\n"); + return bd70528_wdt_change(w, 0); +} + +static int bd70528_wdt_set_timeout(struct watchdog_device *wdt, + unsigned int timeout) +{ + unsigned int hours; + unsigned int minutes; + unsigned int seconds; + int ret; + struct wdtbd70528 *w = watchdog_get_drvdata(wdt); + + seconds = timeout; + hours = timeout / (60 * 60); + /* Maximum timeout is 1h 59m 59s => hours is 1 or 0 */ + if (hours) + seconds -= (60 * 60); + minutes = seconds / 60; + seconds = seconds % 60; + + bd70528_wdt_lock(w->mfd); + + ret = bd70528_wdt_set_locked(w, 0); + if (ret) + goto out_unlock; + + ret = regmap_update_bits(w->regmap, BD70528_REG_WDT_HOUR, + BD70528_MASK_WDT_HOUR, hours); + if (ret) { + dev_err(w->dev, "Failed to set WDT hours\n"); + goto out_en_unlock; + } + ret = regmap_update_bits(w->regmap, BD70528_REG_WDT_MINUTE, + BD70528_MASK_WDT_MINUTE, bin2bcd(minutes)); + if (ret) { + dev_err(w->dev, "Failed to set WDT minutes\n"); + goto out_en_unlock; + } + ret = regmap_update_bits(w->regmap, BD70528_REG_WDT_SEC, + BD70528_MASK_WDT_SEC, bin2bcd(seconds)); + if (ret) + dev_err(w->dev, "Failed to set WDT seconds\n"); + else + dev_dbg(w->dev, "WDT tmo set to %u\n", timeout); + +out_en_unlock: + ret = bd70528_wdt_set_locked(w, 1); +out_unlock: + bd70528_wdt_unlock(w->mfd); + + return ret; +} + +static const struct watchdog_info bd70528_wdt_info = { + .identity = "bd70528-wdt", + .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE, +}; + +static const struct watchdog_ops bd70528_wdt_ops = { + .start = bd70528_wdt_start, + .stop = bd70528_wdt_stop, + .set_timeout = bd70528_wdt_set_timeout, +}; + +static int bd70528_wdt_probe(struct platform_device *pdev) +{ + struct rohm_regmap_dev *bd70528; + struct wdtbd70528 *w; + int ret; + unsigned int reg; + + bd70528 = dev_get_drvdata(pdev->dev.parent); + if (!bd70528) { + dev_err(&pdev->dev, "No MFD driver data\n"); + return -EINVAL; + } + w = devm_kzalloc(&pdev->dev, sizeof(*w), GFP_KERNEL); + if (!w) + return -ENOMEM; + + w->regmap = bd70528->regmap; + w->mfd = bd70528; + w->dev = &pdev->dev; + + w->wdt.info = &bd70528_wdt_info; + w->wdt.ops = &bd70528_wdt_ops; + w->wdt.min_hw_heartbeat_ms = WDT_MIN_MS; + w->wdt.max_hw_heartbeat_ms = WDT_MAX_MS; + w->wdt.parent = pdev->dev.parent; + w->wdt.timeout = DEFAULT_TIMEOUT; + watchdog_set_drvdata(&w->wdt, w); + watchdog_init_timeout(&w->wdt, 0, pdev->dev.parent); + + ret = bd70528_wdt_set_timeout(&w->wdt, w->wdt.timeout); + if (ret) { + dev_err(&pdev->dev, "Failed to set the watchdog timeout\n"); + return ret; + } + + bd70528_wdt_lock(w->mfd); + ret = regmap_read(w->regmap, BD70528_REG_WDT_CTRL, ®); + bd70528_wdt_unlock(w->mfd); + + if (ret) { + dev_err(&pdev->dev, "Failed to get the watchdog state\n"); + return ret; + } + if (reg & BD70528_MASK_WDT_EN) { + dev_dbg(&pdev->dev, "watchdog was running during probe\n"); + set_bit(WDOG_HW_RUNNING, &w->wdt.status); + } + + ret = devm_watchdog_register_device(&pdev->dev, &w->wdt); + if (ret < 0) + dev_err(&pdev->dev, "watchdog registration failed: %d\n", ret); + + return ret; +} + +static struct platform_driver bd70528_wdt = { + .driver = { + .name = "bd70528-wdt" + }, + .probe = bd70528_wdt_probe, +}; + +module_platform_driver(bd70528_wdt); + +MODULE_AUTHOR("Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>"); +MODULE_DESCRIPTION("BD70528 watchdog driver"); +MODULE_LICENSE("GPL"); |