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watchdog:rit_wdt: Add support for WDIOF_CARDRESET

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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 <huaqian.li@siemens.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20230718021007.1338761-4-huaqian.li@siemens.com
[groeck: vaddr == NULL --> !vaddr]
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
This commit is contained in:
Li Hua Qian 2023-07-18 10:10:07 +08:00 committed by Wim Van Sebroeck
parent 11efe9e3f8
commit f20ca595ae
1 changed files with 48 additions and 0 deletions
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48
drivers/watchdog/rti_wdt.c
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@ -14,6 +14,8 @@
#include <linux/mod_devicetable.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/types.h>
@ -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);