From f20ca595ae23314db0383940a184317333c46662 Mon Sep 17 00:00:00 2001 From: Li Hua Qian Date: Tue, 18 Jul 2023 10:10:07 +0800 Subject: watchdog:rit_wdt: Add support for WDIOF_CARDRESET This patch adds the WDIOF_CARDRESET support for the platform watchdog whose hardware does not support this feature, to know if the board reboot is due to a watchdog reset. This is done via reserved memory(RAM), which indicates if specific info saved, triggering the watchdog reset in last boot. Signed-off-by: Li Hua Qian Reviewed-by: Guenter Roeck Link: https://lore.kernel.org/r/20230718021007.1338761-4-huaqian.li@siemens.com [groeck: vaddr == NULL --> !vaddr] Signed-off-by: Guenter Roeck Signed-off-by: Wim Van Sebroeck --- drivers/watchdog/rti_wdt.c | 48 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 48 insertions(+) (limited to 'drivers/watchdog') diff --git a/drivers/watchdog/rti_wdt.c b/drivers/watchdog/rti_wdt.c index ce8f18e93aa9..8e1be7ba0103 100644 --- a/drivers/watchdog/rti_wdt.c +++ b/drivers/watchdog/rti_wdt.c @@ -14,6 +14,8 @@ #include #include #include +#include +#include #include #include #include @@ -52,6 +54,11 @@ #define DWDST BIT(1) +#define PON_REASON_SOF_NUM 0xBBBBCCCC +#define PON_REASON_MAGIC_NUM 0xDDDDDDDD +#define PON_REASON_EOF_NUM 0xCCCCBBBB +#define RESERVED_MEM_MIN_SIZE 12 + static int heartbeat = DEFAULT_HEARTBEAT; /* @@ -198,6 +205,11 @@ static int rti_wdt_probe(struct platform_device *pdev) struct rti_wdt_device *wdt; struct clk *clk; u32 last_ping = 0; + struct device_node *node; + u32 reserved_mem_size; + struct resource res; + u32 *vaddr; + u64 paddr; wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL); if (!wdt) @@ -284,6 +296,42 @@ static int rti_wdt_probe(struct platform_device *pdev) } } + node = of_parse_phandle(pdev->dev.of_node, "memory-region", 0); + if (node) { + ret = of_address_to_resource(node, 0, &res); + if (ret) { + dev_err(dev, "No memory address assigned to the region.\n"); + goto err_iomap; + } + + /* + * If reserved memory is defined for watchdog reset cause. + * Readout the Power-on(PON) reason and pass to bootstatus. + */ + paddr = res.start; + reserved_mem_size = resource_size(&res); + if (reserved_mem_size < RESERVED_MEM_MIN_SIZE) { + dev_err(dev, "The size of reserved memory is too small.\n"); + ret = -EINVAL; + goto err_iomap; + } + + vaddr = memremap(paddr, reserved_mem_size, MEMREMAP_WB); + if (!vaddr) { + dev_err(dev, "Failed to map memory-region.\n"); + ret = -ENOMEM; + goto err_iomap; + } + + if (vaddr[0] == PON_REASON_SOF_NUM && + vaddr[1] == PON_REASON_MAGIC_NUM && + vaddr[2] == PON_REASON_EOF_NUM) { + wdd->bootstatus |= WDIOF_CARDRESET; + } + memset(vaddr, 0, reserved_mem_size); + memunmap(vaddr); + } + watchdog_init_timeout(wdd, heartbeat, dev); ret = watchdog_register_device(wdd); -- cgit v1.2.3