diff options
Diffstat (limited to 'drivers/watchdog/imx7ulp_wdt.c')
| -rw-r--r-- | drivers/watchdog/imx7ulp_wdt.c | 79 |
1 files changed, 65 insertions, 14 deletions
diff --git a/drivers/watchdog/imx7ulp_wdt.c b/drivers/watchdog/imx7ulp_wdt.c index 7993c8c41b3a..922b60374295 100644 --- a/drivers/watchdog/imx7ulp_wdt.c +++ b/drivers/watchdog/imx7ulp_wdt.c @@ -5,6 +5,7 @@ #include <linux/clk.h> #include <linux/io.h> +#include <linux/iopoll.h> #include <linux/kernel.h> #include <linux/module.h> #include <linux/of.h> @@ -21,6 +22,8 @@ #define WDOG_CS_CLK (LPO_CLK << LPO_CLK_SHIFT) #define WDOG_CS_EN BIT(7) #define WDOG_CS_UPDATE BIT(5) +#define WDOG_CS_WAIT BIT(1) +#define WDOG_CS_STOP BIT(0) #define WDOG_CNT 0x4 #define WDOG_TOVAL 0x8 @@ -36,6 +39,7 @@ #define DEFAULT_TIMEOUT 60 #define MAX_TIMEOUT 128 #define WDOG_CLOCK_RATE 1000 +#define WDOG_WAIT_TIMEOUT 20 static bool nowayout = WATCHDOG_NOWAYOUT; module_param(nowayout, bool, 0000); @@ -48,17 +52,40 @@ struct imx7ulp_wdt_device { struct clk *clk; }; -static void imx7ulp_wdt_enable(struct watchdog_device *wdog, bool enable) +static int imx7ulp_wdt_wait(void __iomem *base, u32 mask) +{ + u32 val = readl(base + WDOG_CS); + + if (!(val & mask) && readl_poll_timeout_atomic(base + WDOG_CS, val, + val & mask, 0, + WDOG_WAIT_TIMEOUT)) + return -ETIMEDOUT; + + return 0; +} + +static int imx7ulp_wdt_enable(struct watchdog_device *wdog, bool enable) { struct imx7ulp_wdt_device *wdt = watchdog_get_drvdata(wdog); u32 val = readl(wdt->base + WDOG_CS); + int ret; + local_irq_disable(); writel(UNLOCK, wdt->base + WDOG_CNT); + ret = imx7ulp_wdt_wait(wdt->base, WDOG_CS_ULK); + if (ret) + goto enable_out; if (enable) writel(val | WDOG_CS_EN, wdt->base + WDOG_CS); else writel(val & ~WDOG_CS_EN, wdt->base + WDOG_CS); + imx7ulp_wdt_wait(wdt->base, WDOG_CS_RCS); + +enable_out: + local_irq_enable(); + + return ret; } static bool imx7ulp_wdt_is_enabled(void __iomem *base) @@ -79,17 +106,12 @@ static int imx7ulp_wdt_ping(struct watchdog_device *wdog) static int imx7ulp_wdt_start(struct watchdog_device *wdog) { - - imx7ulp_wdt_enable(wdog, true); - - return 0; + return imx7ulp_wdt_enable(wdog, true); } static int imx7ulp_wdt_stop(struct watchdog_device *wdog) { - imx7ulp_wdt_enable(wdog, false); - - return 0; + return imx7ulp_wdt_enable(wdog, false); } static int imx7ulp_wdt_set_timeout(struct watchdog_device *wdog, @@ -97,22 +119,37 @@ static int imx7ulp_wdt_set_timeout(struct watchdog_device *wdog, { struct imx7ulp_wdt_device *wdt = watchdog_get_drvdata(wdog); u32 val = WDOG_CLOCK_RATE * timeout; + int ret; + local_irq_disable(); writel(UNLOCK, wdt->base + WDOG_CNT); + ret = imx7ulp_wdt_wait(wdt->base, WDOG_CS_ULK); + if (ret) + goto timeout_out; writel(val, wdt->base + WDOG_TOVAL); + imx7ulp_wdt_wait(wdt->base, WDOG_CS_RCS); wdog->timeout = timeout; - return 0; +timeout_out: + local_irq_enable(); + + return ret; } static int imx7ulp_wdt_restart(struct watchdog_device *wdog, unsigned long action, void *data) { struct imx7ulp_wdt_device *wdt = watchdog_get_drvdata(wdog); + int ret; + + ret = imx7ulp_wdt_enable(wdog, true); + if (ret) + return ret; - imx7ulp_wdt_enable(wdog, true); - imx7ulp_wdt_set_timeout(&wdt->wdd, 1); + ret = imx7ulp_wdt_set_timeout(&wdt->wdd, 1); + if (ret) + return ret; /* wait for wdog to fire */ while (true) @@ -136,19 +173,31 @@ static const struct watchdog_info imx7ulp_wdt_info = { WDIOF_MAGICCLOSE, }; -static void imx7ulp_wdt_init(void __iomem *base, unsigned int timeout) +static int imx7ulp_wdt_init(void __iomem *base, unsigned int timeout) { u32 val; + int ret; + local_irq_disable(); /* unlock the wdog for reconfiguration */ writel_relaxed(UNLOCK_SEQ0, base + WDOG_CNT); writel_relaxed(UNLOCK_SEQ1, base + WDOG_CNT); + ret = imx7ulp_wdt_wait(base, WDOG_CS_ULK); + if (ret) + goto init_out; /* set an initial timeout value in TOVAL */ writel(timeout, base + WDOG_TOVAL); /* enable 32bit command sequence and reconfigure */ - val = WDOG_CS_CMD32EN | WDOG_CS_CLK | WDOG_CS_UPDATE; + val = WDOG_CS_CMD32EN | WDOG_CS_CLK | WDOG_CS_UPDATE | + WDOG_CS_WAIT | WDOG_CS_STOP; writel(val, base + WDOG_CS); + imx7ulp_wdt_wait(base, WDOG_CS_RCS); + +init_out: + local_irq_enable(); + + return ret; } static void imx7ulp_wdt_action(void *data) @@ -199,7 +248,9 @@ static int imx7ulp_wdt_probe(struct platform_device *pdev) watchdog_stop_on_reboot(wdog); watchdog_stop_on_unregister(wdog); watchdog_set_drvdata(wdog, imx7ulp_wdt); - imx7ulp_wdt_init(imx7ulp_wdt->base, wdog->timeout * WDOG_CLOCK_RATE); + ret = imx7ulp_wdt_init(imx7ulp_wdt->base, wdog->timeout * WDOG_CLOCK_RATE); + if (ret) + return ret; return devm_watchdog_register_device(dev, wdog); } |