From: Li Hua Qian <[email protected]>
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 <[email protected]>
---
drivers/watchdog/rti_wdt.c | 51 ++++++++++++++++++++++++++++++++++++++
1 file changed, 51 insertions(+)
diff --git a/drivers/watchdog/rti_wdt.c b/drivers/watchdog/rti_wdt.c
index ce8f18e93aa9..b9435b972cb9 100644
--- a/drivers/watchdog/rti_wdt.c
+++ b/drivers/watchdog/rti_wdt.c
@@ -18,6 +18,8 @@
#include <linux/pm_runtime.h>
#include <linux/types.h>
#include <linux/watchdog.h>
+#include <linux/of_address.h>
+#include <linux/of.h>
#define DEFAULT_HEARTBEAT 60
@@ -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 +296,45 @@ static int rti_wdt_probe(struct platform_device *pdev)
}
}
+ node = of_parse_phandle(pdev->dev.of_node, "memory-region", 0);
+ if (!node) {
+ dev_dbg(dev, "No memory-region specified.\n");
+ } else {
+ 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 = res.end - (res.start - 1);
+ 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 == NULL) {
+ 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) {
+ dev_dbg(dev, "Watchdog reset cause detected.\n");
+ wdd->bootstatus |= WDIOF_CARDRESET;
+ }
+ memset(vaddr, 0, reserved_mem_size);
+ memunmap(vaddr);
+ }
+
watchdog_init_timeout(wdd, heartbeat, dev);
ret = watchdog_register_device(wdd);
--
2.34.1
On 7/13/23 02:51, [email protected] wrote:
> From: Li Hua Qian <[email protected]>
>
> 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 <[email protected]>
> ---
> drivers/watchdog/rti_wdt.c | 51 ++++++++++++++++++++++++++++++++++++++
> 1 file changed, 51 insertions(+)
>
> diff --git a/drivers/watchdog/rti_wdt.c b/drivers/watchdog/rti_wdt.c
> index ce8f18e93aa9..b9435b972cb9 100644
> --- a/drivers/watchdog/rti_wdt.c
> +++ b/drivers/watchdog/rti_wdt.c
> @@ -18,6 +18,8 @@
> #include <linux/pm_runtime.h>
> #include <linux/types.h>
> #include <linux/watchdog.h>
> +#include <linux/of_address.h>
> +#include <linux/of.h>
>
This driver so far managed to keep include files in alphabetic order.
Please keep it that way.
> #define DEFAULT_HEARTBEAT 60
>
> @@ -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 +296,45 @@ static int rti_wdt_probe(struct platform_device *pdev)
> }
> }
>
> + node = of_parse_phandle(pdev->dev.of_node, "memory-region", 0);
> + if (!node) {
> + dev_dbg(dev, "No memory-region specified.\n");
If you really want that debug message, please keep the action part
first. I personally think it is just noise; the devicetree can always
be looked up if needed.
> + } else {
> + 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 = res.end - (res.start - 1);
Please use resource_size().
> + 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 == NULL) {
> + 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) {
> + dev_dbg(dev, "Watchdog reset cause detected.\n");
Isn't that a bit pointless ? That is obvious when reading the boot status.
> + wdd->bootstatus |= WDIOF_CARDRESET;
> + }
> + memset(vaddr, 0, reserved_mem_size);
> + memunmap(vaddr);
> + }
> +
> watchdog_init_timeout(wdd, heartbeat, dev);
>
> ret = watchdog_register_device(wdd);