diff options
Diffstat (limited to 'drivers/watchdog/omap_wdt.c')
| -rw-r--r-- | drivers/watchdog/omap_wdt.c | 114 |
1 files changed, 114 insertions, 0 deletions
diff --git a/drivers/watchdog/omap_wdt.c b/drivers/watchdog/omap_wdt.c index 343adb00c7..86f7cf1aaf 100644 --- a/drivers/watchdog/omap_wdt.c +++ b/drivers/watchdog/omap_wdt.c @@ -42,10 +42,14 @@ #include <asm/io.h> #include <asm/processor.h> #include <asm/arch/cpu.h> +#include <wdt.h> +#include <dm.h> +#include <errno.h> /* Hardware timeout in seconds */ #define WDT_HW_TIMEOUT 60 +#if !CONFIG_IS_ENABLED(WDT) static unsigned int wdt_trgr_pattern = 0x1234; void hw_watchdog_reset(void) @@ -134,3 +138,113 @@ void hw_watchdog_init(void) while ((readl(&wdt->wdtwwps)) & WDT_WWPS_PEND_WSPR) ; } +#else +static int omap3_wdt_reset(struct udevice *dev) +{ + struct omap3_wdt_priv *priv = dev_get_priv(dev); + + priv->wdt_trgr_pattern = 0x1234; +/* + * Somebody just triggered watchdog reset and write to WTGR register + * is in progress. It is resetting right now, no need to trigger it + * again + */ + if ((readl(&priv->regs->wdtwwps)) & WDT_WWPS_PEND_WTGR) + return 0; + + priv->wdt_trgr_pattern = ~(priv->wdt_trgr_pattern); + writel(priv->wdt_trgr_pattern, &priv->regs->wdtwtgr); +/* + * Don't wait for posted write to complete, i.e. don't check + * WDT_WWPS_PEND_WTGR bit in WWPS register. There is no writes to + * WTGR register outside of this func, and if entering it + * we see WDT_WWPS_PEND_WTGR bit set, it means watchdog reset + * was just triggered. This prevents us from wasting time in busy + * polling of WDT_WWPS_PEND_WTGR bit. + */ + return 0; +} + +static int omap3_wdt_stop(struct udevice *dev) +{ + struct omap3_wdt_priv *priv = dev_get_priv(dev); + +/* disable watchdog */ + writel(0xAAAA, &priv->regs->wdtwspr); + while (readl(&priv->regs->wdtwwps) != 0x0) + ; + writel(0x5555, &priv->regs->wdtwspr); + while (readl(&priv->regs->wdtwwps) != 0x0) + ; + return 0; +} + +static int omap3_wdt_start(struct udevice *dev, u64 timeout_ms, ulong flags) +{ + struct omap3_wdt_priv *priv = dev_get_priv(dev); + u32 pre_margin = GET_WLDR_VAL(timeout_ms); +/* + * Make sure the watchdog is disabled. This is unfortunately required + * because writing to various registers with the watchdog running has no + * effect. + */ + omap3_wdt_stop(dev); + +/* initialize prescaler */ + while (readl(&priv->regs->wdtwwps) & WDT_WWPS_PEND_WCLR) + ; + + writel(WDT_WCLR_PRE | (PTV << WDT_WCLR_PTV_OFF), &priv->regs->wdtwclr); + while (readl(&priv->regs->wdtwwps) & WDT_WWPS_PEND_WCLR) + ; +/* just count up at 32 KHz */ + while (readl(&priv->regs->wdtwwps) & WDT_WWPS_PEND_WLDR) + ; + + writel(pre_margin, &priv->regs->wdtwldr); + while (readl(&priv->regs->wdtwwps) & WDT_WWPS_PEND_WLDR) + ; +/* Sequence to enable the watchdog */ + writel(0xBBBB, &priv->regs->wdtwspr); + while ((readl(&priv->regs->wdtwwps)) & WDT_WWPS_PEND_WSPR) + ; + + writel(0x4444, &priv->regs->wdtwspr); + while ((readl(&priv->regs->wdtwwps)) & WDT_WWPS_PEND_WSPR) + ; + + return 0; +} + +static int omap3_wdt_probe(struct udevice *dev) +{ + struct omap3_wdt_priv *priv = dev_get_priv(dev); + + priv->regs = (struct wd_timer *)devfdt_get_addr(dev); + if (!priv->regs) + return -EINVAL; + + debug("%s: Probing wdt%u\n", __func__, dev->seq); + return 0; +} + +static const struct wdt_ops omap3_wdt_ops = { + .start = omap3_wdt_start, + .stop = omap3_wdt_stop, + .reset = omap3_wdt_reset, +}; + +static const struct udevice_id omap3_wdt_ids[] = { + { .compatible = "ti,omap3-wdt" }, + { } +}; + +U_BOOT_DRIVER(omap3_wdt) = { + .name = "omap3_wdt", + .id = UCLASS_WDT, + .of_match = omap3_wdt_ids, + .ops = &omap3_wdt_ops, + .probe = omap3_wdt_probe, + .priv_auto_alloc_size = sizeof(struct omap3_wdt_priv), +}; +#endif /* !CONFIG_IS_ENABLED(WDT) */ |