| Message ID | 20230713095127.1230109-4-huaqian.li@siemens.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Add support for WDIOF_CARDRESET on TI AM65x | expand |
On 7/13/23 02:51, huaqian.li@siemens.com wrote: > From: Li Hua Qian <huaqian.li@siemens.com> > > 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> > --- > 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);
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);