diff options
Diffstat (limited to 'drivers/watchdog/stpmic1_wdt.c')
| -rw-r--r-- | drivers/watchdog/stpmic1_wdt.c | 223 |
1 files changed, 223 insertions, 0 deletions
diff --git a/drivers/watchdog/stpmic1_wdt.c b/drivers/watchdog/stpmic1_wdt.c new file mode 100644 index 0000000000..eb8c43f716 --- /dev/null +++ b/drivers/watchdog/stpmic1_wdt.c @@ -0,0 +1,223 @@ +// SPDX-License-Identifier: GPL-2.0+ OR BSD-3-Clause +/* + * Copyright (C) 2018, STMicroelectronics - All Rights Reserved + */ + +#include <common.h> +#include <init.h> +#include <watchdog.h> +#include <asm/io.h> +#include <of_device.h> +#include <linux/iopoll.h> +#include <poweroff.h> +#include <mfd/syscon.h> +#include <restart.h> +#include <reset_source.h> + +#define RESTART_SR 0x05 +#define MAIN_CR 0x10 +#define WCHDG_CR 0x1B +#define WCHDG_TIMER_CR 0x1C + +/* Restart Status Register (RESTART_SR) */ +#define R_RST BIT(0) +#define R_SWOFF BIT(1) +#define R_WDG BIT(2) +#define R_PKEYLKP BIT(3) +#define R_VINOK_FA BIT(4) + +/* Main PMIC Control Register (MAIN_CR) */ +#define SWOFF BIT(0) +#define RREQ_EN BIT(1) + +/* Watchdog Control Register (WCHDG_CR) */ +#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 + + +struct stpmic1_reset_reason { + uint32_t mask; + enum reset_src_type type; + int instance; +}; + +struct stpmic1_wdt { + struct watchdog wdd; + struct restart_handler restart; + struct poweroff_handler poweroff; + struct regmap *regmap; + unsigned int timeout; +}; + +static inline struct stpmic1_wdt *to_stpmic1_wdt(struct watchdog *wdd) +{ + return container_of(wdd, struct stpmic1_wdt, wdd); +} + +static int stpmic1_wdt_ping(struct regmap *regmap) +{ + return regmap_update_bits(regmap, WCHDG_CR, WDT_PING_MASK, WDT_PING); +} + +static int stpmic1_wdt_start(struct regmap *regmap, unsigned int timeout) +{ + int ret = regmap_write(regmap, WCHDG_TIMER_CR, timeout - 1); + if (ret) + return ret; + + return regmap_update_bits(regmap, WCHDG_CR, WDT_START_MASK, WDT_START); +} + +static int stpmic1_wdt_stop(struct regmap *regmap) +{ + return regmap_update_bits(regmap, WCHDG_CR, WDT_START_MASK, WDT_STOP); +} + +static int stpmic1_wdt_set_timeout(struct watchdog *wdd, unsigned int timeout) +{ + struct stpmic1_wdt *wdt = to_stpmic1_wdt(wdd); + int ret; + + if (!timeout) + return stpmic1_wdt_stop(wdt->regmap); + + if (timeout < PMIC_WDT_MIN_TIMEOUT || timeout > wdd->timeout_max) + return -EINVAL; + + if (wdt->timeout == timeout) + return stpmic1_wdt_ping(wdt->regmap); + + ret = stpmic1_wdt_start(wdt->regmap, timeout); + if (ret) + return ret; + + wdt->timeout = timeout; + return 0; +} + +static void __noreturn stpmic1_restart_handler(struct restart_handler *rst) +{ + struct stpmic1_wdt *wdt = container_of(rst, struct stpmic1_wdt, restart); + + regmap_write_bits(wdt->regmap, MAIN_CR, + SWOFF | RREQ_EN, SWOFF | RREQ_EN); + + mdelay(1000); + hang(); +} + +static void __noreturn stpmic1_poweroff(struct poweroff_handler *handler) +{ + struct stpmic1_wdt *wdt = container_of(handler, struct stpmic1_wdt, poweroff); + + shutdown_barebox(); + + regmap_write_bits(wdt->regmap, MAIN_CR, + SWOFF | RREQ_EN, SWOFF); + + mdelay(1000); + hang(); +} + +static const struct stpmic1_reset_reason stpmic1_reset_reasons[] = { + { R_VINOK_FA, RESET_BROWNOUT, 0 }, + { R_PKEYLKP, RESET_EXT, 0 }, + { R_WDG, RESET_WDG, 2 }, + { R_SWOFF, RESET_RST, 0 }, + { R_RST, RESET_EXT, 0 }, + { /* sentinel */ } +}; + +static int stpmic1_set_reset_reason(struct regmap *map) +{ + enum reset_src_type type = RESET_POR; + u32 reg; + int ret; + int i, instance = 0; + + ret = regmap_read(map, RESTART_SR, ®); + if (ret) + return ret; + + for (i = 0; stpmic1_reset_reasons[i].mask; i++) { + if (reg & stpmic1_reset_reasons[i].mask) { + type = stpmic1_reset_reasons[i].type; + instance = stpmic1_reset_reasons[i].instance; + break; + } + } + + reset_source_set_prinst(type, 400, instance); + + pr_info("STPMIC1 reset reason %s (RESTART_SR: 0x%08x)\n", + reset_source_name(), reg); + + return 0; +} + +static int stpmic1_wdt_probe(struct device_d *dev) +{ + struct stpmic1_wdt *wdt; + struct watchdog *wdd; + int ret; + + wdt = xzalloc(sizeof(*wdt)); + wdt->regmap = dev->parent->priv; + + wdd = &wdt->wdd; + wdd->hwdev = dev; + wdd->set_timeout = stpmic1_wdt_set_timeout; + wdd->timeout_max = PMIC_WDT_MAX_TIMEOUT; + wdd->timeout_cur = PMIC_WDT_DEFAULT_TIMEOUT; + + /* have the watchdog reset, not power-off the system */ + regmap_write_bits(wdt->regmap, MAIN_CR, RREQ_EN, RREQ_EN); + + ret = watchdog_register(wdd); + if (ret) { + dev_err(dev, "Failed to register watchdog device\n"); + return ret; + } + + wdt->restart.name = "stpmic1-reset"; + wdt->restart.restart = stpmic1_restart_handler; + wdt->restart.priority = 300; + + ret = restart_handler_register(&wdt->restart); + if (ret) + dev_warn(dev, "Cannot register restart handler\n"); + + wdt->poweroff.name = "stpmic1-poweroff"; + wdt->poweroff.poweroff = stpmic1_poweroff; + wdt->poweroff.priority = 200; + + ret = poweroff_handler_register(&wdt->poweroff); + if (ret) + dev_warn(dev, "Cannot register poweroff handler\n"); + + stpmic1_set_reset_reason(wdt->regmap); + if (ret) + dev_warn(dev, "Cannot query reset reason\n"); + + dev_info(dev, "probed\n"); + return 0; +} + +static __maybe_unused const struct of_device_id stpmic1_wdt_of_match[] = { + { .compatible = "st,stpmic1-wdt" }, + { /* sentinel */ } +}; + +static struct driver_d stpmic1_wdt_driver = { + .name = "stpmic1-wdt", + .probe = stpmic1_wdt_probe, + .of_compatible = DRV_OF_COMPAT(stpmic1_wdt_of_match), +}; +device_platform_driver(stpmic1_wdt_driver); |