diff options
| -rw-r--r-- | drivers/watchdog/sama5d4_wdt.c | 48 |
1 files changed, 30 insertions, 18 deletions
diff --git a/drivers/watchdog/sama5d4_wdt.c b/drivers/watchdog/sama5d4_wdt.c index f709962018ac..5cee20caca78 100644 --- a/drivers/watchdog/sama5d4_wdt.c +++ b/drivers/watchdog/sama5d4_wdt.c @@ -44,6 +44,8 @@ MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); +#define wdt_enabled (!(wdt->mr & AT91_WDT_WDDIS)) + #define wdt_read(wdt, field) \ readl_relaxed((wdt)->reg_base + (field)) @@ -89,7 +91,16 @@ static int sama5d4_wdt_set_timeout(struct watchdog_device *wdd, wdt->mr &= ~AT91_WDT_WDD; wdt->mr |= AT91_WDT_SET_WDV(value); wdt->mr |= AT91_WDT_SET_WDD(value); - wdt_write(wdt, AT91_WDT_MR, wdt->mr); + + /* + * WDDIS has to be 0 when updating WDD/WDV. The datasheet states: When + * setting the WDDIS bit, and while it is set, the fields WDV and WDD + * must not be modified. + * If the watchdog is enabled, then the timeout can be updated. Else, + * wait that the user enables it. + */ + if (wdt_enabled) + wdt_write(wdt, AT91_WDT_MR, wdt->mr & ~AT91_WDT_WDDIS); wdd->timeout = timeout; @@ -145,23 +156,20 @@ static int of_sama5d4_wdt_init(struct device_node *np, struct sama5d4_wdt *wdt) static int sama5d4_wdt_init(struct sama5d4_wdt *wdt) { - struct watchdog_device *wdd = &wdt->wdd; - u32 value = WDT_SEC2TICKS(wdd->timeout); u32 reg; - /* - * Because the fields WDV and WDD must not be modified when the WDDIS - * bit is set, so clear the WDDIS bit before writing the WDT_MR. + * When booting and resuming, the bootloader may have changed the + * watchdog configuration. + * If the watchdog is already running, we can safely update it. + * Else, we have to disable it properly. */ - reg = wdt_read(wdt, AT91_WDT_MR); - reg &= ~AT91_WDT_WDDIS; - wdt_write(wdt, AT91_WDT_MR, reg); - - wdt->mr |= AT91_WDT_SET_WDD(value); - wdt->mr |= AT91_WDT_SET_WDV(value); - - wdt_write(wdt, AT91_WDT_MR, wdt->mr); - + if (wdt_enabled) { + wdt_write(wdt, AT91_WDT_MR, wdt->mr); + } else { + reg = wdt_read(wdt, AT91_WDT_MR); + if (!(reg & AT91_WDT_WDDIS)) + wdt_write(wdt, AT91_WDT_MR, reg | AT91_WDT_WDDIS); + } return 0; } @@ -172,6 +180,7 @@ static int sama5d4_wdt_probe(struct platform_device *pdev) struct resource *res; void __iomem *regs; u32 irq = 0; + u32 timeout; int ret; wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL); @@ -221,6 +230,11 @@ static int sama5d4_wdt_probe(struct platform_device *pdev) return ret; } + timeout = WDT_SEC2TICKS(wdd->timeout); + + wdt->mr |= AT91_WDT_SET_WDD(timeout); + wdt->mr |= AT91_WDT_SET_WDV(timeout); + ret = sama5d4_wdt_init(wdt); if (ret) return ret; @@ -263,9 +277,7 @@ static int sama5d4_wdt_resume(struct device *dev) { struct sama5d4_wdt *wdt = dev_get_drvdata(dev); - wdt_write(wdt, AT91_WDT_MR, wdt->mr & ~AT91_WDT_WDDIS); - if (wdt->mr & AT91_WDT_WDDIS) - wdt_write(wdt, AT91_WDT_MR, wdt->mr); + sama5d4_wdt_init(wdt); return 0; } |