ARM: BCM2835: Drop the init_irq() hook.

Since the WDT is what's used to drive restart and power off, it makes more sense to keep it there, where the regs are already mapped and definitions for them provided. Note that this means you may need to add CONFIG_BCM2835_WDT to retain functionality of your kernel.

Signed-off-by Eric Anholt <[email protected]>

Cc linux-watchdog at vger.kernel.org

Since the WDT is what's used to drive restart and power off, it makes more sense to keep it there, where the regs are already mapped and definitions for them provided. Note that this means you may need to add CONFIG_BCM2835_WDT to retain functionality of your kernel.

Note that power off has never worked for me, and just reboots as well. So I can't say that I've *really* tested the power off code.

drivers/watchdog/bcm2835_wdt.c static struct watchdog_device bcm2835_wdt_wdd = { · line 147

Quoted 13 lines · On Friday 24 April 2015 12:08:54 Eric Anholt wrote:

drivers/watchdog/bcm2835_wdt.c +13 -0

+/*
+ * We can't really power off, but if we do the normal reset scheme, and
+ * indicate to bootcode.bin not to reboot, then most of the chip will be
+ * powered off.
+ */
+static void bcm2835_power_off(void)
+{
+       struct device_node *np =
+               of_find_compatible_node(NULL, NULL, "brcm,bcm2835-pm-wdt");
+       struct platform_device *pdev = of_find_device_by_node(np);
+       struct bcm2835_wdt *wdt = platform_get_drvdata(pdev);
+       u32 val;
+

Instead of doing the lookup again here, I'd suggest using a static variable in the driver to store the device pointer for the device used on power_off.

Make sure that the device remove callback assigns it back to NULL though and that the function checks for NULL pointer.

Quoted 18 lines · Arnd Bergmann

drivers/watchdog/bcm2835_wdt.c static struct watchdog_device bcm2835_wdt_wdd = { · line 147

Quoted 13 lines · On Friday 24 April 2015 12:08:54 Eric Anholt wrote:

drivers/watchdog/bcm2835_wdt.c +13 -0

+/*
+ * We can't really power off, but if we do the normal reset scheme, and
+ * indicate to bootcode.bin not to reboot, then most of the chip will be
+ * powered off.
+ */
+static void bcm2835_power_off(void)
+{
+       struct device_node *np =
+               of_find_compatible_node(NULL, NULL, "brcm,bcm2835-pm-wdt");
+       struct platform_device *pdev = of_find_device_by_node(np);
+       struct bcm2835_wdt *wdt = platform_get_drvdata(pdev);
+       u32 val;
+

Instead of doing the lookup again here, I'd suggest using a static variable in the driver to store the device pointer for the device used on power_off.

Quoted 3 lines

Make sure that the device remove callback assigns it back to NULL though and that the function checks for NULL pointer.

Why would that be needed ?

Quoted 23 lines · On Sunday 26 April 2015 08:35:57 Guenter Roeck wrote:

Quoted 21 lines · Arnd Bergmann

drivers/watchdog/bcm2835_wdt.c static struct watchdog_device bcm2835_wdt_wdd = { · line 147

Quoted 13 lines · On Friday 24 April 2015 12:08:54 Eric Anholt wrote:

drivers/watchdog/bcm2835_wdt.c +13 -0

+/*
+ * We can't really power off, but if we do the normal reset scheme, and
+ * indicate to bootcode.bin not to reboot, then most of the chip will be
+ * powered off.
+ */
+static void bcm2835_power_off(void)
+{
+       struct device_node *np =
+               of_find_compatible_node(NULL, NULL, "brcm,bcm2835-pm-wdt");
+       struct platform_device *pdev = of_find_device_by_node(np);
+       struct bcm2835_wdt *wdt = platform_get_drvdata(pdev);
+       u32 val;
+

Instead of doing the lookup again here, I'd suggest using a static variable in the driver to store the device pointer for the device used on power_off.

Make sure that the device remove callback assigns it back to NULL though and that the function checks for NULL pointer.

Quoted 1 line

Why would that be needed ?

devices can be unbound from drivers through sysfs, or using dynamic DT updates. If one does that, the watchdog driver will correctly destroy all information it has about the device, so if the power_off function still uses that pointer, it will crash.

Quoted 26 lines · Arnd Bergmann

Quoted 24 lines · On Sunday 26 April 2015 08:35:57 Guenter Roeck wrote:

Quoted 18 lines · Arnd Bergmann

drivers/watchdog/bcm2835_wdt.c static struct watchdog_device bcm2835_wdt_wdd = { · line 147

Quoted 13 lines · On Friday 24 April 2015 12:08:54 Eric Anholt wrote:

drivers/watchdog/bcm2835_wdt.c +13 -0

+/*
+ * We can't really power off, but if we do the normal reset scheme, and
+ * indicate to bootcode.bin not to reboot, then most of the chip will be
+ * powered off.
+ */
+static void bcm2835_power_off(void)
+{
+       struct device_node *np =
+               of_find_compatible_node(NULL, NULL, "brcm,bcm2835-pm-wdt");
+       struct platform_device *pdev = of_find_device_by_node(np);
+       struct bcm2835_wdt *wdt = platform_get_drvdata(pdev);
+       u32 val;
+

Instead of doing the lookup again here, I'd suggest using a static variable in the driver to store the device pointer for the device used on power_off.

Quoted 3 lines

Make sure that the device remove callback assigns it back to NULL though and that the function checks for NULL pointer.

Why would that be needed ?

Quoted 5 lines

devices can be unbound from drivers through sysfs, or using dynamic DT updates. If one does that, the watchdog driver will correctly destroy all information it has about the device, so if the power_off function still uses that pointer, it will crash.

Without calling its remove function ? That sounds odd. Lots of drivers would break if that was really the case.

Quoted 27 lines · On Monday 27 April 2015 05:44:14 Guenter Roeck wrote:

Quoted 26 lines · Arnd Bergmann

Quoted 24 lines · On Sunday 26 April 2015 08:35:57 Guenter Roeck wrote:

Quoted 18 lines · Arnd Bergmann

drivers/watchdog/bcm2835_wdt.c static struct watchdog_device bcm2835_wdt_wdd = { · line 147

Quoted 13 lines · On Friday 24 April 2015 12:08:54 Eric Anholt wrote:

drivers/watchdog/bcm2835_wdt.c +13 -0

+/*
+ * We can't really power off, but if we do the normal reset scheme, and
+ * indicate to bootcode.bin not to reboot, then most of the chip will be
+ * powered off.
+ */
+static void bcm2835_power_off(void)
+{
+       struct device_node *np =
+               of_find_compatible_node(NULL, NULL, "brcm,bcm2835-pm-wdt");
+       struct platform_device *pdev = of_find_device_by_node(np);
+       struct bcm2835_wdt *wdt = platform_get_drvdata(pdev);
+       u32 val;
+

Instead of doing the lookup again here, I'd suggest using a static variable in the driver to store the device pointer for the device used on power_off.

Quoted 3 lines

Make sure that the device remove callback assigns it back to NULL though and that the function checks for NULL pointer.

Why would that be needed ?

Quoted 7 lines

Quoted 5 lines

devices can be unbound from drivers through sysfs, or using dynamic DT updates. If one does that, the watchdog driver will correctly destroy all information it has about the device, so if the power_off function still uses that pointer, it will crash.

Without calling its remove function ? That sounds odd. Lots of drivers would break if that was really the case.

I'm not sure what you mean now. The remove function gets called to do the final cleanup, and afterwards the device is deleted, so the remove function should make sure that no global variables point to the device any more.

This is not a concern for most other drivers, because they do not keep global pointers to device structures.

Quoted 1 line

The pointer to the power-off handler is removed in the device remove callback, and thus won't be called after the device is unbound.

Ultimately this is similar the the current code, which assumes that the call to of_find_device_by_node(np) never fails.

Since the WDT is what's used to drive restart and power off, it makes more sense to keep it there, where the regs are already mapped and definitions for them provided. Note that this means you may need to add CONFIG_BCM2835_WDT to retain functionality of your kernel.

Signed-off-by Eric Anholt <[email protected]>

Cc linux-watchdog at vger.kernel.org

Since the WDT is what's used to drive restart and power off, it makes more sense to keep it there, where the regs are already mapped and definitions for them provided. Note that this means you may need to add CONFIG_BCM2835_WDT to retain functionality of your kernel.

Signed-off-by Eric Anholt <[email protected]>

Cc linux-watchdog at vger.kernel.org

Quoted 7 lines · Eric Anholt

Since the WDT is what's used to drive restart and power off, it makes more sense to keep it there, where the regs are already mapped and definitions for them provided. Note that this means you may need to add CONFIG_BCM2835_WDT to retain functionality of your kernel.

Signed-off-by Eric Anholt <[email protected]>

Cc linux-watchdog at vger.kernel.org

The patch will require a rebase to v4.0-rc1.

Quoted 6 lines · Guenter Roeck

Quoted 5 lines · Eric Anholt

Since the WDT is what's used to drive restart and power off, it makes more sense to keep it there, where the regs are already mapped and definitions for them provided. Note that this means you may need to add CONFIG_BCM2835_WDT to retain functionality of your kernel.

Quoted 5 lines

Quoted 2 lines

Signed-off-by Eric Anholt <[email protected]>

Cc linux-watchdog at vger.kernel.org

The patch will require a rebase to v4.0-rc1.

s/4.0/4.1/

Quoted 10 lines · Guenter Roeck

Quoted 9 lines · Guenter Roeck

Quoted 7 lines · Eric Anholt

Since the WDT is what's used to drive restart and power off, it makes more sense to keep it there, where the regs are already mapped and definitions for them provided. Note that this means you may need to add CONFIG_BCM2835_WDT to retain functionality of your kernel.

Signed-off-by Eric Anholt <[email protected]>

Cc linux-watchdog at vger.kernel.org

Quoted 3 lines

Quoted 2 lines

The patch will require a rebase to v4.0-rc1.

s/4.0/4.1/

It will? It seems to work fine, and the diff's the same. Is there some new thing you were expecting in a rebase?

Quoted 12 lines · Eric Anholt

Quoted 10 lines · Guenter Roeck

Quoted 9 lines · Guenter Roeck

Quoted 7 lines · Eric Anholt

Since the WDT is what's used to drive restart and power off, it makes more sense to keep it there, where the regs are already mapped and definitions for them provided. Note that this means you may need to add CONFIG_BCM2835_WDT to retain functionality of your kernel.

Signed-off-by Eric Anholt <[email protected]>

Cc linux-watchdog at vger.kernel.org

Quoted 7 lines

Quoted 3 lines

Quoted 2 lines

The patch will require a rebase to v4.0-rc1.

s/4.0/4.1/

It will? It seems to work fine, and the diff's the same. Is there some new thing you were expecting in a rebase?

All I can say is that it didn't apply for me. Maybe someone else has more luck.

Quoted 12 lines · Eric Anholt

Quoted 10 lines · Guenter Roeck

Quoted 9 lines · Guenter Roeck

Quoted 7 lines · Eric Anholt

Since the WDT is what's used to drive restart and power off, it makes more sense to keep it there, where the regs are already mapped and definitions for them provided. Note that this means you may need to add CONFIG_BCM2835_WDT to retain functionality of your kernel.

Signed-off-by Eric Anholt <[email protected]>

Cc linux-watchdog at vger.kernel.org

Quoted 7 lines

Quoted 3 lines

Quoted 2 lines

The patch will require a rebase to v4.0-rc1.

s/4.0/4.1/

It will? It seems to work fine, and the diff's the same. Is there some new thing you were expecting in a rebase?

All I can say is that it didn't apply for me. Maybe someone else has more luck.

Since the WDT is what's used to drive restart and power off, it makes more sense to keep it there, where the regs are already mapped and definitions for them provided. Note that this means you may need to add CONFIG_BCM2835_WDT to retain functionality of your kernel.

Signed-off-by Eric Anholt <[email protected]>

Cc linux-watchdog at vger.kernel.org

---

Note that power off has never worked for me, and just reboots as well. So I can't say that I've *really* tested the power off code.

 arch/arm/mach-bcm/board_bcm2835.c | 73 ---------------------------------------
 drivers/watchdog/bcm2835_wdt.c    | 62 +++++++++++++++++++++++++++++++++
 2 files changed, 62 insertions(+), 73 deletions(-)

arch/arm/mach-bcm/board_bcm2835.c +0 -73

index 49dd5b0..0f7b9ea 100644
@@ -12,7 +12,6 @@
  * GNU General Public License for more details.
  */
 
-#include <linux/delay.h>
 #include <linux/init.h>
 #include <linux/irqchip.h>
 #include <linux/of_address.h>

@@ -22,81 +21,10 @@
 #include <asm/mach/arch.h>
 #include <asm/mach/map.h>
 
-#define PM_RSTC				0x1c
-#define PM_RSTS				0x20
-#define PM_WDOG				0x24
-
-#define PM_PASSWORD			0x5a000000
-#define PM_RSTC_WRCFG_MASK		0x00000030
-#define PM_RSTC_WRCFG_FULL_RESET	0x00000020
-#define PM_RSTS_HADWRH_SET		0x00000040
-
-static void __iomem *wdt_regs;
-
-/*
- * The machine restart method can be called from an atomic context so we won't
- * be able to ioremap the regs then.
- */
-static void bcm2835_setup_restart(void)
-{
-	struct device_node *np = of_find_compatible_node(NULL, NULL,
-						"brcm,bcm2835-pm-wdt");
-	if (WARN(!np, "unable to setup watchdog restart"))
-		return;
-
-	wdt_regs = of_iomap(np, 0);
-	WARN(!wdt_regs, "failed to remap watchdog regs");
-}
-
-static void bcm2835_restart(enum reboot_mode mode, const char *cmd)
-{
-	u32 val;
-
-	if (!wdt_regs)
-		return;
-
-	/* use a timeout of 10 ticks (~150us) */
-	writel_relaxed(10 | PM_PASSWORD, wdt_regs + PM_WDOG);
-	val = readl_relaxed(wdt_regs + PM_RSTC);
-	val &= ~PM_RSTC_WRCFG_MASK;
-	val |= PM_PASSWORD | PM_RSTC_WRCFG_FULL_RESET;
-	writel_relaxed(val, wdt_regs + PM_RSTC);
-
-	/* No sleeping, possibly atomic. */
-	mdelay(1);
-}
-
-/*
- * We can't really power off, but if we do the normal reset scheme, and
- * indicate to bootcode.bin not to reboot, then most of the chip will be
- * powered off.
- */
-static void bcm2835_power_off(void)
-{
-	u32 val;
-
-	/*
-	 * We set the watchdog hard reset bit here to distinguish this reset
-	 * from the normal (full) reset. bootcode.bin will not reboot after a
-	 * hard reset.
-	 */
-	val = readl_relaxed(wdt_regs + PM_RSTS);
-	val &= ~PM_RSTC_WRCFG_MASK;
-	val |= PM_PASSWORD | PM_RSTS_HADWRH_SET;
-	writel_relaxed(val, wdt_regs + PM_RSTS);
-
-	/* Continue with normal reset mechanism */
-	bcm2835_restart(REBOOT_HARD, "");
-}
-
 static void __init bcm2835_init(void)
 {
 	int ret;
 
-	bcm2835_setup_restart();
-	if (wdt_regs)
-		pm_power_off = bcm2835_power_off;
-
 	bcm2835_init_clocks();
 
 	ret = of_platform_populate(NULL, of_default_bus_match_table, NULL,

@@ -114,6 +42,5 @@ static const char * const bcm2835_compat[] = {
 
 DT_MACHINE_START(BCM2835, "BCM2835")
 	.init_machine = bcm2835_init,
-	.restart = bcm2835_restart,
 	.dt_compat = bcm2835_compat
 MACHINE_END

drivers/watchdog/bcm2835_wdt.c +62 -0

index 2b5a9bb..7116968 100644
@@ -13,20 +13,25 @@
  * option) any later version.
  */
 
+#include <linux/delay.h>
+#include <linux/reboot.h>
 #include <linux/types.h>
 #include <linux/module.h>
 #include <linux/io.h>
 #include <linux/watchdog.h>
 #include <linux/platform_device.h>
 #include <linux/of_address.h>
+#include <linux/of_platform.h>
 
 #define PM_RSTC				0x1c
+#define PM_RSTS				0x20
 #define PM_WDOG				0x24
 
 #define PM_PASSWORD			0x5a000000
 
 #define PM_WDOG_TIME_SET		0x000fffff
 #define PM_RSTC_WRCFG_CLR		0xffffffcf
+#define PM_RSTS_HADWRH_SET		0x00000040
 #define PM_RSTC_WRCFG_SET		0x00000030
 #define PM_RSTC_WRCFG_FULL_RESET	0x00000020
 #define PM_RSTC_RESET			0x00000102

@@ -37,6 +42,7 @@
 struct bcm2835_wdt {
 	void __iomem		*base;
 	spinlock_t		lock;
+	struct notifier_block	restart_handler;
 };
 
 static unsigned int heartbeat;

@@ -106,6 +112,53 @@ static struct watchdog_device bcm2835_wdt_wdd = {
 	.timeout =	WDOG_TICKS_TO_SECS(PM_WDOG_TIME_SET),
 };
 
+static int
+bcm2835_restart(struct notifier_block *this, unsigned long mode, void *cmd)
+{
+	struct bcm2835_wdt *wdt = container_of(this, struct bcm2835_wdt,
+					       restart_handler);
+	u32 val;
+
+	/* use a timeout of 10 ticks (~150us) */
+	writel_relaxed(10 | PM_PASSWORD, wdt->base + PM_WDOG);
+	val = readl_relaxed(wdt->base + PM_RSTC);
+	val &= PM_RSTC_WRCFG_CLR;
+	val |= PM_PASSWORD | PM_RSTC_WRCFG_FULL_RESET;
+	writel_relaxed(val, wdt->base + PM_RSTC);
+
+	/* No sleeping, possibly atomic. */
+	mdelay(1);
+
+	return 0;
+}
+
+/*
+ * We can't really power off, but if we do the normal reset scheme, and
+ * indicate to bootcode.bin not to reboot, then most of the chip will be
+ * powered off.
+ */
+static void bcm2835_power_off(void)
+{
+	struct device_node *np =
+		of_find_compatible_node(NULL, NULL, "brcm,bcm2835-pm-wdt");
+	struct platform_device *pdev = of_find_device_by_node(np);
+	struct bcm2835_wdt *wdt = platform_get_drvdata(pdev);
+	u32 val;
+
+	/*
+	 * We set the watchdog hard reset bit here to distinguish this reset
+	 * from the normal (full) reset. bootcode.bin will not reboot after a
+	 * hard reset.
+	 */
+	val = readl_relaxed(wdt->base + PM_RSTS);
+	val &= PM_RSTC_WRCFG_CLR;
+	val |= PM_PASSWORD | PM_RSTS_HADWRH_SET;
+	writel_relaxed(val, wdt->base + PM_RSTS);
+
+	/* Continue with normal reset mechanism */
+	bcm2835_restart(&wdt->restart_handler, REBOOT_HARD, NULL);
+}
+
 static int bcm2835_wdt_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;

@@ -136,6 +189,12 @@ static int bcm2835_wdt_probe(struct platform_device *pdev)
 		return err;
 	}
 
+	wdt->restart_handler.notifier_call = bcm2835_restart;
+	wdt->restart_handler.priority = 128;
+	register_restart_handler(&wdt->restart_handler);
+	if (pm_power_off == NULL)
+		pm_power_off = bcm2835_power_off;
+
 	dev_info(dev, "Broadcom BCM2835 watchdog timer");
 	return 0;
 }

@@ -144,6 +203,9 @@ static int bcm2835_wdt_remove(struct platform_device *pdev)
 {
 	struct bcm2835_wdt *wdt = platform_get_drvdata(pdev);
 
+	unregister_restart_handler(&wdt->restart_handler);
+	if (pm_power_off == bcm2835_power_off)
+		pm_power_off = NULL;
 	watchdog_unregister_device(&bcm2835_wdt_wdd);
 	iounmap(wdt->base);
 

Since the WDT is what's used to drive restart and power off, it makes more sense to keep it there, where the regs are already mapped and definitions for them provided. Note that this means you may need to add CONFIG_BCM2835_WDT to retain functionality of your kernel.

Signed-off-by Eric Anholt <[email protected]>

Cc linux-watchdog at vger.kernel.org

Acked-by Stephen Warren <[email protected]>

Tested-by Stephen Warren <[email protected]>

Acked-by Lubomir Rintel <[email protected]>

Since the WDT is what's used to drive restart and power off, it makes more sense to keep it there, where the regs are already mapped and definitions for them provided. Note that this means you may need to add CONFIG_BCM2835_WDT to retain functionality of your kernel.

Signed-off-by Eric Anholt <[email protected]>

Cc linux-watchdog at vger.kernel.org

---

Note that power off has never worked for me, and just reboots as well. So I can't say that I've *really* tested the power off code.

 arch/arm/mach-bcm/board_bcm2835.c | 73 ---------------------------------------
 drivers/watchdog/bcm2835_wdt.c    | 62 +++++++++++++++++++++++++++++++++
 2 files changed, 62 insertions(+), 73 deletions(-)

arch/arm/mach-bcm/board_bcm2835.c +0 -73

index 49dd5b0..0f7b9ea 100644
@@ -12,7 +12,6 @@
  * GNU General Public License for more details.
  */
 
-#include <linux/delay.h>
 #include <linux/init.h>
 #include <linux/irqchip.h>
 #include <linux/of_address.h>

@@ -22,81 +21,10 @@
 #include <asm/mach/arch.h>
 #include <asm/mach/map.h>
 
-#define PM_RSTC				0x1c
-#define PM_RSTS				0x20
-#define PM_WDOG				0x24
-
-#define PM_PASSWORD			0x5a000000
-#define PM_RSTC_WRCFG_MASK		0x00000030
-#define PM_RSTC_WRCFG_FULL_RESET	0x00000020
-#define PM_RSTS_HADWRH_SET		0x00000040
-
-static void __iomem *wdt_regs;
-
-/*
- * The machine restart method can be called from an atomic context so we won't
- * be able to ioremap the regs then.
- */
-static void bcm2835_setup_restart(void)
-{
-	struct device_node *np = of_find_compatible_node(NULL, NULL,
-						"brcm,bcm2835-pm-wdt");
-	if (WARN(!np, "unable to setup watchdog restart"))
-		return;
-
-	wdt_regs = of_iomap(np, 0);
-	WARN(!wdt_regs, "failed to remap watchdog regs");
-}
-
-static void bcm2835_restart(enum reboot_mode mode, const char *cmd)
-{
-	u32 val;
-
-	if (!wdt_regs)
-		return;
-
-	/* use a timeout of 10 ticks (~150us) */
-	writel_relaxed(10 | PM_PASSWORD, wdt_regs + PM_WDOG);
-	val = readl_relaxed(wdt_regs + PM_RSTC);
-	val &= ~PM_RSTC_WRCFG_MASK;
-	val |= PM_PASSWORD | PM_RSTC_WRCFG_FULL_RESET;
-	writel_relaxed(val, wdt_regs + PM_RSTC);
-
-	/* No sleeping, possibly atomic. */
-	mdelay(1);
-}
-
-/*
- * We can't really power off, but if we do the normal reset scheme, and
- * indicate to bootcode.bin not to reboot, then most of the chip will be
- * powered off.
- */
-static void bcm2835_power_off(void)
-{
-	u32 val;
-
-	/*
-	 * We set the watchdog hard reset bit here to distinguish this reset
-	 * from the normal (full) reset. bootcode.bin will not reboot after a
-	 * hard reset.
-	 */
-	val = readl_relaxed(wdt_regs + PM_RSTS);
-	val &= ~PM_RSTC_WRCFG_MASK;
-	val |= PM_PASSWORD | PM_RSTS_HADWRH_SET;
-	writel_relaxed(val, wdt_regs + PM_RSTS);
-
-	/* Continue with normal reset mechanism */
-	bcm2835_restart(REBOOT_HARD, "");
-}
-
 static void __init bcm2835_init(void)
 {
 	int ret;
 
-	bcm2835_setup_restart();
-	if (wdt_regs)
-		pm_power_off = bcm2835_power_off;
-
 	bcm2835_init_clocks();
 
 	ret = of_platform_populate(NULL, of_default_bus_match_table, NULL,

@@ -114,6 +42,5 @@ static const char * const bcm2835_compat[] = {
 
 DT_MACHINE_START(BCM2835, "BCM2835")
 	.init_machine = bcm2835_init,
-	.restart = bcm2835_restart,
 	.dt_compat = bcm2835_compat
 MACHINE_END

drivers/watchdog/bcm2835_wdt.c +62 -0

index 2b5a9bb..7116968 100644
@@ -13,20 +13,25 @@
  * option) any later version.
  */
 
+#include <linux/delay.h>
+#include <linux/reboot.h>
 #include <linux/types.h>
 #include <linux/module.h>
 #include <linux/io.h>
 #include <linux/watchdog.h>
 #include <linux/platform_device.h>
 #include <linux/of_address.h>
+#include <linux/of_platform.h>
 
 #define PM_RSTC				0x1c
+#define PM_RSTS				0x20
 #define PM_WDOG				0x24
 
 #define PM_PASSWORD			0x5a000000
 
 #define PM_WDOG_TIME_SET		0x000fffff
 #define PM_RSTC_WRCFG_CLR		0xffffffcf
+#define PM_RSTS_HADWRH_SET		0x00000040
 #define PM_RSTC_WRCFG_SET		0x00000030
 #define PM_RSTC_WRCFG_FULL_RESET	0x00000020
 #define PM_RSTC_RESET			0x00000102

@@ -37,6 +42,7 @@
 struct bcm2835_wdt {
 	void __iomem		*base;
 	spinlock_t		lock;
+	struct notifier_block	restart_handler;
 };
 
 static unsigned int heartbeat;

@@ -106,6 +112,53 @@ static struct watchdog_device bcm2835_wdt_wdd = {
 	.timeout =	WDOG_TICKS_TO_SECS(PM_WDOG_TIME_SET),
 };
 
+static int
+bcm2835_restart(struct notifier_block *this, unsigned long mode, void *cmd)
+{
+	struct bcm2835_wdt *wdt = container_of(this, struct bcm2835_wdt,
+					       restart_handler);
+	u32 val;
+
+	/* use a timeout of 10 ticks (~150us) */
+	writel_relaxed(10 | PM_PASSWORD, wdt->base + PM_WDOG);
+	val = readl_relaxed(wdt->base + PM_RSTC);
+	val &= PM_RSTC_WRCFG_CLR;
+	val |= PM_PASSWORD | PM_RSTC_WRCFG_FULL_RESET;
+	writel_relaxed(val, wdt->base + PM_RSTC);
+
+	/* No sleeping, possibly atomic. */
+	mdelay(1);
+
+	return 0;
+}
+
+/*
+ * We can't really power off, but if we do the normal reset scheme, and
+ * indicate to bootcode.bin not to reboot, then most of the chip will be
+ * powered off.
+ */
+static void bcm2835_power_off(void)
+{
+	struct device_node *np =
+		of_find_compatible_node(NULL, NULL, "brcm,bcm2835-pm-wdt");
+	struct platform_device *pdev = of_find_device_by_node(np);
+	struct bcm2835_wdt *wdt = platform_get_drvdata(pdev);
+	u32 val;
+
+	/*
+	 * We set the watchdog hard reset bit here to distinguish this reset
+	 * from the normal (full) reset. bootcode.bin will not reboot after a
+	 * hard reset.
+	 */
+	val = readl_relaxed(wdt->base + PM_RSTS);
+	val &= PM_RSTC_WRCFG_CLR;
+	val |= PM_PASSWORD | PM_RSTS_HADWRH_SET;
+	writel_relaxed(val, wdt->base + PM_RSTS);
+
+	/* Continue with normal reset mechanism */
+	bcm2835_restart(&wdt->restart_handler, REBOOT_HARD, NULL);
+}
+
 static int bcm2835_wdt_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;

@@ -136,6 +189,12 @@ static int bcm2835_wdt_probe(struct platform_device *pdev)
 		return err;
 	}
 
+	wdt->restart_handler.notifier_call = bcm2835_restart;
+	wdt->restart_handler.priority = 128;
+	register_restart_handler(&wdt->restart_handler);
+	if (pm_power_off == NULL)
+		pm_power_off = bcm2835_power_off;
+
 	dev_info(dev, "Broadcom BCM2835 watchdog timer");
 	return 0;
 }

@@ -144,6 +203,9 @@ static int bcm2835_wdt_remove(struct platform_device *pdev)
 {
 	struct bcm2835_wdt *wdt = platform_get_drvdata(pdev);
 
+	unregister_restart_handler(&wdt->restart_handler);
+	if (pm_power_off == bcm2835_power_off)
+		pm_power_off = NULL;
 	watchdog_unregister_device(&bcm2835_wdt_wdd);
 	iounmap(wdt->base);
 

This is the default function that gets called if the hook is NULL.

Signed-off-by Eric Anholt <[email protected]>

---
 arch/arm/mach-bcm/board_bcm2835.c | 1 -
 1 file changed, 1 deletion(-)

arch/arm/mach-bcm/board_bcm2835.c +0 -1

index 9851ee8..49dd5b0 100644
@@ -113,7 +113,6 @@ static const char * const bcm2835_compat[] = {
 };
 
 DT_MACHINE_START(BCM2835, "BCM2835")
-	.init_irq = irqchip_init,
 	.init_machine = bcm2835_init,
 	.restart = bcm2835_restart,
 	.dt_compat = bcm2835_compat