watchdog: pnx4008: add restart handler

From: Sylvain Lemieux <[email protected]>

The LPC32xx provide the capability to perform a soft or hard reset; a soft reset will no reset the external peripheral
(i.e. RESOUT_N output not asserted).

This changeset migrate the restart code from the "mach-lpc32xx" to the "pnx-4008" watchdog driver and add the soft reset capability.

The default behavior (i.e. hard reset) remain unchanged.

This patchset have a dependency on the following patch:
watchdog: Add 'action' and 'data' parameters to restart handler callback
http://permalink.gmane.org/gmane.linux.watchdog/3364/

Note:
Patch #5 was generated with the option "--unified=2" to ensure it can be apply before or after the changes for the new LPC32xx irqchip driver:
- http://permalink.gmane.org/gmane.linux.drivers.devicetree/144683
---
Changes from v4 to v5:
* Rebased on the following patch:
http://permalink.gmane.org/gmane.linux.watchdog/3364/

Changes from v3 to v4:
* Update the patch as per the feedback received from:
Arnd: http://permalink.gmane.org/gmane.linux.watchdog/3329
- Switch patch #5 and #6 order.

Changes from v2 to v3:
* Update the patch as per the feedback received from:
Joachim: http://permalink.gmane.org/gmane.linux.watchdog/3303
- remove explicit clock enable from restart handler.
- verify "register_restart_handler" return value.
- add call to unregister_restart_handler".
- do the restart handling directly in "pnx4008_restart_handler".
* Move the change to "phy3250.c" into a separate patch and generate the new patch with the "--unified=2" option.

Changes from v1 to v2:
* Rename patch title;
was "arm: lpc32xx: restart: add support for soft reset"
* Update the patch as per the feedback received from:
Joachim: http://permalink.gmane.org/gmane.linux.ports.arm.kernel/479791
- migrate restart code from "mach-lpc32xx" to "pnx-4008" driver.
* Add soft reset support to "pnx-4008" driver instead of "mach-lpc32xx".
* Use define available in "pnx-4008" when writting to watchdog register.
* Remove restart handler from "mach-lpc32xx".
* Remove restart hook from "phy3250.c".
* Update driver logging during power-on.

Sylvain Lemieux (6):
watchdog: pnx4008: update logging during power-on
watchdog: pnx4008: add restart handler
watchdog: pnx4008: add support for soft reset
watchdog: pnx4008: restart: support "cmd" from userspace
arm: lpc32xx: phy3250 remove restart hook
arm: lpc32xx: remove restart handler

 arch/arm/mach-lpc32xx/common.c  | 15 ---------------
 arch/arm/mach-lpc32xx/common.h  |  1 -
 arch/arm/mach-lpc32xx/phy3250.c |  1 -
 drivers/watchdog/pnx4008_wdt.c  | 42 +++++++++++++++++++++++++++++++++++++++--
 4 files changed, 40 insertions(+), 19 deletions(-)

1.8.3.1

From: Sylvain Lemieux <[email protected]>

There is no need add the driver name in the text to display
on the console during the power-on:
pnx4008-watchdog 4003c000.watchdog: PNX4008 Watchdog Timer: heartbeat 19 sec

---
Changes from v4 to v5:
- Added Reviewed-by from v4.

Changes from v3 to v4:
- none.

Changes from v2 to v3:
- none.

Changes from v1 to v2:
- new patch in v2.

 drivers/watchdog/pnx4008_wdt.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

index 313cd1c..88264a2 100644
@@ -178,8 +178,7 @@ static int pnx4008_wdt_probe(struct platform_device *pdev)
 		goto disable_clk;
 	}
 
-	dev_info(&pdev->dev, "PNX4008 Watchdog Timer: heartbeat %d sec\n",
-		 pnx4008_wdd.timeout);
+	dev_info(&pdev->dev, "heartbeat %d sec\n", pnx4008_wdd.timeout);
 
 	return 0;
 

1.8.3.1

From: Sylvain Lemieux <[email protected]>

Add restart handler capability to the driver;
the restart handler implementation was taken from
"mach-lpc32xx" ("lpc23xx_restart" function).

---
Changes from v4 to v5:
- Rebased on the following patch:
http://permalink.gmane.org/gmane.linux.watchdog/3364/

Changes from v3 to v4:
- none.

Changes from v2 to v3:
- remove explicit clock enable from restart handler.
- verify "register_restart_handler" return value.
- add call to unregister_restart_handler".
- do the restart handling directly in "pnx4008_restart_handler".

Changes from v1 to v2:
- new patch in v2.

 drivers/watchdog/pnx4008_wdt.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

index 88264a2..f3be522 100644
@@ -31,6 +31,8 @@
 #include <linux/slab.h>
 #include <linux/err.h>
 #include <linux/of.h>
+#include <linux/delay.h>
+#include <linux/reboot.h>
 #include <mach/hardware.h>
 
 /* WatchDog Timer - Chapter 23 Page 207 */

@@ -124,6 +126,19 @@ static int pnx4008_wdt_set_timeout(struct watchdog_device *wdd,
 	return 0;
 }
 
+static int pnx4008_restart_handler(struct watchdog_device *wdd,
+				   unsigned long mode, void *cmd)
+{
+	/* Instant assert of RESETOUT_N with pulse length 1mS */
+	writel(13000, WDTIM_PULSE(wdt_base));
+	writel(M_RES2 | RESFRC1 | RESFRC2, WDTIM_MCTRL(wdt_base));
+
+	/* Wait for watchdog to reset system */
+	mdelay(1000);
+
+	return NOTIFY_DONE;
+}
+
 static const struct watchdog_info pnx4008_wdt_ident = {
 	.options = WDIOF_CARDRESET | WDIOF_MAGICCLOSE |
 	    WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,

@@ -135,6 +150,7 @@ static const struct watchdog_ops pnx4008_wdt_ops = {
 	.start = pnx4008_wdt_start,
 	.stop = pnx4008_wdt_stop,
 	.set_timeout = pnx4008_wdt_set_timeout,
+	.restart = pnx4008_restart_handler,
 };
 
 static struct watchdog_device pnx4008_wdd = {

@@ -169,6 +185,7 @@ static int pnx4008_wdt_probe(struct platform_device *pdev)
 			WDIOF_CARDRESET : 0;
 	pnx4008_wdd.parent = &pdev->dev;
 	watchdog_set_nowayout(&pnx4008_wdd, nowayout);
+	watchdog_set_restart_priority(&pnx4008_wdd, 128);
 
 	pnx4008_wdt_stop(&pnx4008_wdd);	/* disable for now */
 

1.8.3.1

From: Sylvain Lemieux <[email protected]>

Add support for explicit soft reset using the reboot mode.

The default reboot mode behavior is unchanged;
you can overwrite the default reboot type in the board specific file "DT_MACHINE_START" definition using the "reboot_mode" parameter.

---
Changes from v4 to v5:
- no logical change; updated to work with new revision of patch #2.

Changes from v3 to v4:
- none.

Changes from v2 to v3:
- no logical change; updated to work with new revision of patch #2.

Changes from v1 to v2:
- Rename patch title;
was "arm: lpc32xx: restart: add support for soft reset"
- Add change to "pnx-4008" driver instead of "mach-lpc32xx".
- Use define available in "pnx-4008" when writting to watchdog register.

 drivers/watchdog/pnx4008_wdt.c | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

index f3be522..e05bfecf 100644
@@ -129,9 +129,16 @@ static int pnx4008_wdt_set_timeout(struct watchdog_device *wdd,
 static int pnx4008_restart_handler(struct watchdog_device *wdd,
 				   unsigned long mode, void *cmd)
 {
-	/* Instant assert of RESETOUT_N with pulse length 1mS */
-	writel(13000, WDTIM_PULSE(wdt_base));
-	writel(M_RES2 | RESFRC1 | RESFRC2, WDTIM_MCTRL(wdt_base));
+	if (mode == (unsigned long)REBOOT_SOFT) {
+		/* Force match output active */
+		writel(EXT_MATCH0, WDTIM_EMR(wdt_base));
+		/* Internal reset on match output (RESOUT_N not asserted) */
+		writel(M_RES1, WDTIM_MCTRL(wdt_base));
+	} else {
+		/* Instant assert of RESETOUT_N with pulse length 1mS */
+		writel(13000, WDTIM_PULSE(wdt_base));
+		writel(M_RES2 | RESFRC1 | RESFRC2, WDTIM_MCTRL(wdt_base));
+	}
 
 	/* Wait for watchdog to reset system */
 	mdelay(1000);

1.8.3.1

typecasts are optional; the compare occurred between "unsigned long" & "enum reboot_mode" types.

Do you want me to remove them?

Sylvain

If they are not needed, they should not be there. Cluttering the core with unnecessary typecasts only makes it harder to read.

Thanks,
Guenter

From: Sylvain Lemieux <[email protected]>

Added support to verify if a "cmd" is passed from the userspace program rebooting the system;
- if a valid "cmd" is available, handle it;
- If the received "cmd" is not supported, use the default reboot mode.

---
Changes from v4 to v5:
- no logical change; updated to work with new revision of patch #2.

Changes from v3 to v4:
- none.

Changes from v2 to v3:
- no logical change; updated to work with new revision of patch #2.

Changes from v1 to v2:
- Rename patch title;
was "arm: lpc32xx: restart: support "cmd" from userspace"
- Add change to "pnx-4008" driver instead of "mach-lpc32xx".

 drivers/watchdog/pnx4008_wdt.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

index e05bfecf..df76231 100644
@@ -129,6 +129,21 @@ static int pnx4008_wdt_set_timeout(struct watchdog_device *wdd,
 static int pnx4008_restart_handler(struct watchdog_device *wdd,
 				   unsigned long mode, void *cmd)
 {
+	const char *boot_cmd = (const char *)cmd;
+
+	/*
+	 * Verify if a "cmd" passed from the userspace program rebooting
+	 * the system; if available, handle it.
+	 * - For details, see the 'reboot' syscall in kernel/reboot.c
+	 * - If the received "cmd" is not supported, use the default mode.
+	 */
+	if (boot_cmd) {
+		if (boot_cmd[0] == 'h')
+			mode = (unsigned long)REBOOT_HARD;
+		else if (boot_cmd[0] == 's')
+			mode = (unsigned long)REBOOT_SOFT;
+	}
+
 	if (mode == (unsigned long)REBOOT_SOFT) {
 		/* Force match output active */
 		writel(EXT_MATCH0, WDTIM_EMR(wdt_base));

1.8.3.1

From: Sylvain Lemieux <[email protected]>

Remove the restart hook assignment from phy3250;
this functionality is now managed by
the pnx4008 watchdog driver.

---
Note:
This patch was generated with the option "--unified=2" to ensure it can be apply before or after the changes for the new LPC32xx irqchip driver:
- http://permalink.gmane.org/gmane.linux.drivers.devicetree/144683

Changes from v4 to v5:
- none.

Changes from v3 to v4:
- Switch patch #5 and #6 order.

Changes from v2 to v3:
- new patch in v3.

 arch/arm/mach-lpc32xx/phy3250.c | 1 -
 1 file changed, 1 deletion(-)

index a19071a..9e5c3db 100644
@@ -211,4 +211,3 @@ DT_MACHINE_START(LPC32XX_DT, "LPC32XX SoC (Flattened Device Tree)")
 	.init_machine	= lpc3250_machine_init,
 	.dt_compat	= lpc32xx_dt_compat,
-	.restart	= lpc23xx_restart,
 MACHINE_END

1.8.3.1

From: Sylvain Lemieux <[email protected]>

Remove the restart handler from "mach-lpc32xx";
this functionality is now available in the
pnx4008 watchdog driver.

---
Changes from v4 to v5:
- none.

Changes from v3 to v4:
- Switch patch #5 and #6 order.

Changes from v2 to v3:
- move the change to "phy3250.c" into a separate patch.

Changes from v1 to v2:
- new patch in v2.

 arch/arm/mach-lpc32xx/common.c | 15 ---------------
 arch/arm/mach-lpc32xx/common.h |  1 -
 2 files changed, 16 deletions(-)

index 716e83e..5b7a1e7 100644
@@ -194,21 +194,6 @@ void __init lpc32xx_map_io(void)
 	iotable_init(lpc32xx_io_desc, ARRAY_SIZE(lpc32xx_io_desc));
 }
 
-void lpc23xx_restart(enum reboot_mode mode, const char *cmd)
-{
-	/* Make sure WDT clocks are enabled */
-	__raw_writel(LPC32XX_CLKPWR_PWMCLK_WDOG_EN,
-		LPC32XX_CLKPWR_TIMER_CLK_CTRL);
-
-	/* Instant assert of RESETOUT_N with pulse length 1mS */
-	__raw_writel(13000, io_p2v(LPC32XX_WDTIM_BASE + 0x18));
-	__raw_writel(0x70, io_p2v(LPC32XX_WDTIM_BASE + 0xC));
-
-	/* Wait for watchdog to reset system */
-	while (1)
-		;
-}
-
 static int __init lpc32xx_check_uid(void)
 {
 	u32 uid[4];

index 1cd8853..2d90801 100644
@@ -30,7 +30,6 @@ extern void lpc32xx_timer_init(void);
 extern void __init lpc32xx_init_irq(void);
 extern void __init lpc32xx_map_io(void);
 extern void __init lpc32xx_serial_init(void);
-extern void lpc23xx_restart(enum reboot_mode, const char *);
 
 
 /*

1.8.3.1