diff options
| -rw-r--r-- | drivers/watchdog/rti_wdt.c | 112 |
1 files changed, 102 insertions, 10 deletions
diff --git a/drivers/watchdog/rti_wdt.c b/drivers/watchdog/rti_wdt.c index d456dd72d99a..7cbdc178ffe8 100644 --- a/drivers/watchdog/rti_wdt.c +++ b/drivers/watchdog/rti_wdt.c @@ -35,7 +35,11 @@ #define RTIWWDRX_NMI 0xa -#define RTIWWDSIZE_50P 0x50 +#define RTIWWDSIZE_50P 0x50 +#define RTIWWDSIZE_25P 0x500 +#define RTIWWDSIZE_12P5 0x5000 +#define RTIWWDSIZE_6P25 0x50000 +#define RTIWWDSIZE_3P125 0x500000 #define WDENABLE_KEY 0xa98559da @@ -48,7 +52,7 @@ #define DWDST BIT(1) -static int heartbeat; +static int heartbeat = DEFAULT_HEARTBEAT; /* * struct to hold data for each WDT device @@ -79,11 +83,9 @@ static int rti_wdt_start(struct watchdog_device *wdd) * be petted during the open window; not too early or not too late. * The HW configuration options only allow for the open window size * to be 50% or less than that; we obviouly want to configure the open - * window as large as possible so we select the 50% option. To avoid - * any glitches, we accommodate 5% safety margin also, so we setup - * the min_hw_hearbeat at 55% of the timeout period. + * window as large as possible so we select the 50% option. */ - wdd->min_hw_heartbeat_ms = 11 * wdd->timeout * 1000 / 20; + wdd->min_hw_heartbeat_ms = 500 * wdd->timeout; /* Generate NMI when wdt expires */ writel_relaxed(RTIWWDRX_NMI, wdt->base + RTIWWDRXCTRL); @@ -110,7 +112,48 @@ static int rti_wdt_ping(struct watchdog_device *wdd) return 0; } -static unsigned int rti_wdt_get_timeleft(struct watchdog_device *wdd) +static int rti_wdt_setup_hw_hb(struct watchdog_device *wdd, u32 wsize) +{ + /* + * RTI only supports a windowed mode, where the watchdog can only + * be petted during the open window; not too early or not too late. + * The HW configuration options only allow for the open window size + * to be 50% or less than that. + */ + switch (wsize) { + case RTIWWDSIZE_50P: + /* 50% open window => 50% min heartbeat */ + wdd->min_hw_heartbeat_ms = 500 * heartbeat; + break; + + case RTIWWDSIZE_25P: + /* 25% open window => 75% min heartbeat */ + wdd->min_hw_heartbeat_ms = 750 * heartbeat; + break; + + case RTIWWDSIZE_12P5: + /* 12.5% open window => 87.5% min heartbeat */ + wdd->min_hw_heartbeat_ms = 875 * heartbeat; + break; + + case RTIWWDSIZE_6P25: + /* 6.5% open window => 93.5% min heartbeat */ + wdd->min_hw_heartbeat_ms = 935 * heartbeat; + break; + + case RTIWWDSIZE_3P125: + /* 3.125% open window => 96.9% min heartbeat */ + wdd->min_hw_heartbeat_ms = 969 * heartbeat; + break; + + default: + return -EINVAL; + } + + return 0; +} + +static unsigned int rti_wdt_get_timeleft_ms(struct watchdog_device *wdd) { u64 timer_counter; u32 val; @@ -123,11 +166,18 @@ static unsigned int rti_wdt_get_timeleft(struct watchdog_device *wdd) timer_counter = readl_relaxed(wdt->base + RTIDWDCNTR); + timer_counter *= 1000; + do_div(timer_counter, wdt->freq); return timer_counter; } +static unsigned int rti_wdt_get_timeleft(struct watchdog_device *wdd) +{ + return rti_wdt_get_timeleft_ms(wdd) / 1000; +} + static const struct watchdog_info rti_wdt_info = { .options = WDIOF_KEEPALIVEPING, .identity = "K3 RTI Watchdog", @@ -148,6 +198,7 @@ static int rti_wdt_probe(struct platform_device *pdev) struct watchdog_device *wdd; struct rti_wdt_device *wdt; struct clk *clk; + u32 last_ping = 0; wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL); if (!wdt) @@ -169,6 +220,14 @@ static int rti_wdt_probe(struct platform_device *pdev) return -EINVAL; } + /* + * If watchdog is running at 32k clock, it is not accurate. + * Adjust frequency down in this case so that we don't pet + * the watchdog too often. + */ + if (wdt->freq < 32768) + wdt->freq = wdt->freq * 9 / 10; + pm_runtime_enable(dev); ret = pm_runtime_get_sync(dev); if (ret) { @@ -185,11 +244,8 @@ static int rti_wdt_probe(struct platform_device *pdev) wdd->min_timeout = 1; wdd->max_hw_heartbeat_ms = (WDT_PRELOAD_MAX << WDT_PRELOAD_SHIFT) / wdt->freq * 1000; - wdd->timeout = DEFAULT_HEARTBEAT; wdd->parent = dev; - watchdog_init_timeout(wdd, heartbeat, dev); - watchdog_set_drvdata(wdd, wdt); watchdog_set_nowayout(wdd, 1); watchdog_set_restart_priority(wdd, 128); @@ -201,12 +257,48 @@ static int rti_wdt_probe(struct platform_device *pdev) goto err_iomap; } + if (readl(wdt->base + RTIDWDCTRL) == WDENABLE_KEY) { + u32 time_left_ms; + u64 heartbeat_ms; + u32 wsize; + + set_bit(WDOG_HW_RUNNING, &wdd->status); + time_left_ms = rti_wdt_get_timeleft_ms(wdd); + heartbeat_ms = readl(wdt->base + RTIDWDPRLD); + heartbeat_ms <<= WDT_PRELOAD_SHIFT; + heartbeat_ms *= 1000; + do_div(heartbeat_ms, wdt->freq); + if (heartbeat_ms != heartbeat * 1000) + dev_warn(dev, "watchdog already running, ignoring heartbeat config!\n"); + + heartbeat = heartbeat_ms; + heartbeat /= 1000; + + wsize = readl(wdt->base + RTIWWDSIZECTRL); + ret = rti_wdt_setup_hw_hb(wdd, wsize); + if (ret) { + dev_err(dev, "bad window size.\n"); + goto err_iomap; + } + + last_ping = heartbeat_ms - time_left_ms; + if (time_left_ms > heartbeat_ms) { + dev_warn(dev, "time_left > heartbeat? Assuming last ping just before now.\n"); + last_ping = 0; + } + } + + watchdog_init_timeout(wdd, heartbeat, dev); + ret = watchdog_register_device(wdd); if (ret) { dev_err(dev, "cannot register watchdog device\n"); goto err_iomap; } + if (last_ping) + watchdog_set_last_hw_keepalive(wdd, last_ping); + return 0; err_iomap: |