diff options
Diffstat (limited to 'drivers/watchdog/stm32_iwdg.c')
| -rw-r--r-- | drivers/watchdog/stm32_iwdg.c | 95 |
1 files changed, 94 insertions, 1 deletions
diff --git a/drivers/watchdog/stm32_iwdg.c b/drivers/watchdog/stm32_iwdg.c index 5404e0387620..d700e0d49bb9 100644 --- a/drivers/watchdog/stm32_iwdg.c +++ b/drivers/watchdog/stm32_iwdg.c @@ -18,6 +18,7 @@ #include <linux/module.h> #include <linux/of.h> #include <linux/platform_device.h> +#include <linux/pm_wakeirq.h> #include <linux/watchdog.h> #define DEFAULT_TIMEOUT 10 @@ -28,6 +29,7 @@ #define IWDG_RLR 0x08 /* ReLoad Register */ #define IWDG_SR 0x0C /* Status Register */ #define IWDG_WINR 0x10 /* Windows Register */ +#define IWDG_EWCR 0x14 /* Early Wake-up Register */ /* IWDG_KR register bit mask */ #define KR_KEY_RELOAD 0xAAAA /* reload counter enable */ @@ -47,22 +49,29 @@ #define SR_PVU BIT(0) /* Watchdog prescaler value update */ #define SR_RVU BIT(1) /* Watchdog counter reload value update */ +#define EWCR_EWIT GENMASK(11, 0) /* Watchdog counter window value */ +#define EWCR_EWIC BIT(14) /* Watchdog early interrupt acknowledge */ +#define EWCR_EWIE BIT(15) /* Watchdog early interrupt enable */ + /* set timeout to 100000 us */ #define TIMEOUT_US 100000 #define SLEEP_US 1000 struct stm32_iwdg_data { bool has_pclk; + bool has_early_wakeup; u32 max_prescaler; }; static const struct stm32_iwdg_data stm32_iwdg_data = { .has_pclk = false, + .has_early_wakeup = false, .max_prescaler = 256, }; static const struct stm32_iwdg_data stm32mp1_iwdg_data = { .has_pclk = true, + .has_early_wakeup = true, .max_prescaler = 1024, }; @@ -88,13 +97,18 @@ static inline void reg_write(void __iomem *base, u32 reg, u32 val) static int stm32_iwdg_start(struct watchdog_device *wdd) { struct stm32_iwdg *wdt = watchdog_get_drvdata(wdd); - u32 tout, presc, iwdg_rlr, iwdg_pr, iwdg_sr; + u32 tout, ptot, presc, iwdg_rlr, iwdg_ewcr, iwdg_pr, iwdg_sr; int ret; dev_dbg(wdd->parent, "%s\n", __func__); + if (!wdd->pretimeout) + wdd->pretimeout = 3 * wdd->timeout / 4; + tout = clamp_t(unsigned int, wdd->timeout, wdd->min_timeout, wdd->max_hw_heartbeat_ms / 1000); + ptot = clamp_t(unsigned int, tout - wdd->pretimeout, + wdd->min_timeout, tout); presc = DIV_ROUND_UP(tout * wdt->rate, RLR_MAX + 1); @@ -102,6 +116,7 @@ static int stm32_iwdg_start(struct watchdog_device *wdd) presc = roundup_pow_of_two(presc); iwdg_pr = presc <= 1 << PR_SHIFT ? 0 : ilog2(presc) - PR_SHIFT; iwdg_rlr = ((tout * wdt->rate) / presc) - 1; + iwdg_ewcr = ((ptot * wdt->rate) / presc) - 1; /* enable write access */ reg_write(wdt->regs, IWDG_KR, KR_KEY_EWA); @@ -109,6 +124,8 @@ static int stm32_iwdg_start(struct watchdog_device *wdd) /* set prescaler & reload registers */ reg_write(wdt->regs, IWDG_PR, iwdg_pr); reg_write(wdt->regs, IWDG_RLR, iwdg_rlr); + if (wdt->data->has_early_wakeup) + reg_write(wdt->regs, IWDG_EWCR, iwdg_ewcr | EWCR_EWIE); reg_write(wdt->regs, IWDG_KR, KR_KEY_ENABLE); /* wait for the registers to be updated (max 100ms) */ @@ -151,6 +168,34 @@ static int stm32_iwdg_set_timeout(struct watchdog_device *wdd, return 0; } +static int stm32_iwdg_set_pretimeout(struct watchdog_device *wdd, + unsigned int pretimeout) +{ + dev_dbg(wdd->parent, "%s pretimeout: %d sec\n", __func__, pretimeout); + + wdd->pretimeout = pretimeout; + + if (watchdog_active(wdd)) + return stm32_iwdg_start(wdd); + + return 0; +} + +static irqreturn_t stm32_iwdg_isr(int irq, void *wdog_arg) +{ + struct watchdog_device *wdd = wdog_arg; + struct stm32_iwdg *wdt = watchdog_get_drvdata(wdd); + u32 reg; + + reg = reg_read(wdt->regs, IWDG_EWCR); + reg |= EWCR_EWIC; + reg_write(wdt->regs, IWDG_EWCR, reg); + + watchdog_notify_pretimeout(wdd); + + return IRQ_HANDLED; +} + static void stm32_clk_disable_unprepare(void *data) { clk_disable_unprepare(data); @@ -207,11 +252,20 @@ static const struct watchdog_info stm32_iwdg_info = { .identity = "STM32 Independent Watchdog", }; +static const struct watchdog_info stm32_iwdg_preinfo = { + .options = WDIOF_SETTIMEOUT | + WDIOF_MAGICCLOSE | + WDIOF_KEEPALIVEPING | + WDIOF_PRETIMEOUT, + .identity = "STM32 Independent Watchdog", +}; + static const struct watchdog_ops stm32_iwdg_ops = { .owner = THIS_MODULE, .start = stm32_iwdg_start, .ping = stm32_iwdg_ping, .set_timeout = stm32_iwdg_set_timeout, + .set_pretimeout = stm32_iwdg_set_pretimeout, }; static const struct of_device_id stm32_iwdg_of_match[] = { @@ -221,6 +275,40 @@ static const struct of_device_id stm32_iwdg_of_match[] = { }; MODULE_DEVICE_TABLE(of, stm32_iwdg_of_match); +static int stm32_iwdg_irq_init(struct platform_device *pdev, + struct stm32_iwdg *wdt) +{ + struct device_node *np = pdev->dev.of_node; + struct watchdog_device *wdd = &wdt->wdd; + struct device *dev = &pdev->dev; + int irq, ret; + + if (!wdt->data->has_early_wakeup) + return 0; + + irq = platform_get_irq(pdev, 0); + if (irq <= 0) + return 0; + + if (of_property_read_bool(np, "wakeup-source")) { + ret = device_init_wakeup(dev, true); + if (ret) + return ret; + + ret = dev_pm_set_wake_irq(dev, irq); + if (ret) + return ret; + } + + ret = devm_request_irq(dev, irq, stm32_iwdg_isr, 0, + dev_name(dev), wdd); + if (ret) + return ret; + + wdd->info = &stm32_iwdg_preinfo; + return 0; +} + static int stm32_iwdg_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; @@ -255,6 +343,11 @@ static int stm32_iwdg_probe(struct platform_device *pdev) wdd->max_hw_heartbeat_ms = ((RLR_MAX + 1) * wdt->data->max_prescaler * 1000) / wdt->rate; + /* Initialize IRQ, this might override wdd->info, hence it is here. */ + ret = stm32_iwdg_irq_init(pdev, wdt); + if (ret) + return ret; + watchdog_set_drvdata(wdd, wdt); watchdog_set_nowayout(wdd, WATCHDOG_NOWAYOUT); watchdog_init_timeout(wdd, 0, dev); |