The boot status in the watchdog device struct is updated during controller probe stage. Application layer can get the boot status through the command, cat /sys/class/watchdog/watchdogX/bootstatus. The boot status mapping rule follows the latest design guide from the OpenBMC shown as below. https://github.com/openbmc/docs/blob/master/designs/bmc-reboot-cause-update.md#proposed-design - WDIOF_EXTERN1 => system is reset by Software - WDIOF_CARDRESET => system is reset by WDT SoC reset - Others => other reset events, e.g., power on reset. On ASPEED platform, the boot status is recorded in the SCU registers. - AST2400: Only a bit represents for any WDT reset. - AST2500: The reset triggered by different WDT controllers can be distinguished by different SCU bits. But, WDIOF_EXTERN1 or WDIOF_CARDRESET still cannot be identified due to HW limitation. - AST2600: Different from AST2500, additional HW bits are added for distinguishing WDIOF_EXTERN1 and WDIOF_CARDRESET. Besides, since alternating boot event is triggered by WDT SoC reset, it is classified as WDIOF_CARDRESET. Signed-off-by: Chin-Ting Kuo <chin-ting_kuo@xxxxxxxxxxxxxx> --- drivers/watchdog/aspeed_wdt.c | 83 ++++++++++++++++++++++++++++++++++- 1 file changed, 81 insertions(+), 2 deletions(-) diff --git a/drivers/watchdog/aspeed_wdt.c b/drivers/watchdog/aspeed_wdt.c index b4773a6aaf8c..4ad6335ff25b 100644 --- a/drivers/watchdog/aspeed_wdt.c +++ b/drivers/watchdog/aspeed_wdt.c @@ -11,21 +11,31 @@ #include <linux/io.h> #include <linux/kernel.h> #include <linux/kstrtox.h> +#include <linux/mfd/syscon.h> #include <linux/module.h> #include <linux/of.h> #include <linux/of_irq.h> #include <linux/platform_device.h> +#include <linux/regmap.h> #include <linux/watchdog.h> static bool nowayout = WATCHDOG_NOWAYOUT; module_param(nowayout, bool, 0); MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); +struct aspeed_wdt_scu { + const char *compatible; + u32 reset_status_reg; + u32 wdt_reset_mask; + u32 wdt_sw_reset_mask; + u32 wdt_reset_mask_shift; +}; struct aspeed_wdt_config { u32 ext_pulse_width_mask; u32 irq_shift; u32 irq_mask; + struct aspeed_wdt_scu scu; }; struct aspeed_wdt { @@ -39,18 +49,39 @@ static const struct aspeed_wdt_config ast2400_config = { .ext_pulse_width_mask = 0xff, .irq_shift = 0, .irq_mask = 0, + .scu = { + .compatible = "aspeed,ast2400-scu", + .reset_status_reg = 0x3c, + .wdt_reset_mask = 0x1, + .wdt_sw_reset_mask = 0, + .wdt_reset_mask_shift = 1, + }, }; static const struct aspeed_wdt_config ast2500_config = { .ext_pulse_width_mask = 0xfffff, .irq_shift = 12, .irq_mask = GENMASK(31, 12), + .scu = { + .compatible = "aspeed,ast2500-scu", + .reset_status_reg = 0x3c, + .wdt_reset_mask = 0x1, + .wdt_sw_reset_mask = 0, + .wdt_reset_mask_shift = 2, + }, }; static const struct aspeed_wdt_config ast2600_config = { .ext_pulse_width_mask = 0xfffff, .irq_shift = 0, .irq_mask = GENMASK(31, 10), + .scu = { + .compatible = "aspeed,ast2600-scu", + .reset_status_reg = 0x74, + .wdt_reset_mask = 0xf, + .wdt_sw_reset_mask = 0x8, + .wdt_reset_mask_shift = 16, + }, }; static const struct of_device_id aspeed_wdt_of_table[] = { @@ -213,6 +244,52 @@ static int aspeed_wdt_restart(struct watchdog_device *wdd, return 0; } +static int aspeed_wdt_update_bootstatus(struct platform_device *pdev, + struct aspeed_wdt *wdt) +{ + struct resource *res; + struct aspeed_wdt_scu scu = wdt->cfg->scu; + struct regmap *scu_base; + u32 reset_mask_width; + u32 reset_mask_shift; + u32 reg_size = 0; + u32 idx = 0; + u32 status; + int ret; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + reg_size = res->end - res->start; + + if (reg_size != 0) + idx = ((intptr_t)wdt->base & 0x00000fff) / reg_size; + + /* On ast2400, only a bit is used to represent WDT reset */ + if (of_device_is_compatible(pdev->dev.of_node, "aspeed,ast2400-wdt")) + idx = 0; + + scu_base = syscon_regmap_lookup_by_compatible(scu.compatible); + if (IS_ERR(scu_base)) + return PTR_ERR(scu_base); + + ret = regmap_read(scu_base, scu.reset_status_reg, &status); + if (ret) + return ret; + + reset_mask_width = hweight32(scu.wdt_reset_mask); + reset_mask_shift = scu.wdt_reset_mask_shift + + reset_mask_width * idx; + + if (status & (scu.wdt_sw_reset_mask << reset_mask_shift)) + wdt->wdd.bootstatus = WDIOF_EXTERN1; + else if (status & (scu.wdt_reset_mask << reset_mask_shift)) + wdt->wdd.bootstatus = WDIOF_CARDRESET; + else + wdt->wdd.bootstatus = 0; + + return regmap_write(scu_base, scu.reset_status_reg, + scu.wdt_reset_mask << reset_mask_shift); +} + /* access_cs0 shows if cs0 is accessible, hence the reverted bit */ static ssize_t access_cs0_show(struct device *dev, struct device_attribute *attr, char *buf) @@ -458,10 +535,12 @@ static int aspeed_wdt_probe(struct platform_device *pdev) writel(duration - 1, wdt->base + WDT_RESET_WIDTH); } + ret = aspeed_wdt_update_bootstatus(pdev, wdt); + if (ret) + return ret; + status = readl(wdt->base + WDT_TIMEOUT_STATUS); if (status & WDT_TIMEOUT_STATUS_BOOT_SECONDARY) { - wdt->wdd.bootstatus = WDIOF_CARDRESET; - if (of_device_is_compatible(np, "aspeed,ast2400-wdt") || of_device_is_compatible(np, "aspeed,ast2500-wdt")) wdt->wdd.groups = bswitch_groups; -- 2.34.1
