diff mbox

[5/5] ARM: bcm4760: Add restart hook

Message ID 20130721002714.732402573@gmail.com (mailing list archive)
State New, archived
Headers show

Commit Message

Domenico Andreoli July 21, 2013, 12:23 a.m. UTC 
From: Domenico Andreoli <domenico.andreoli@linux.com>

Restart hook implementation for the Broadcom BCM4760 based ARM11 SoCs.

Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Domenico Andreoli <domenico.andreoli@linux.com>
---
 Documentation/devicetree/bindings/watchdog/brcm,bcm4760-pm-wdt.txt |   14 ++
 arch/arm/boot/dts/bcm4760.dtsi                                     |    5 +
 arch/arm/mach-bcm/bcm4760.c                                        |   78 ++++++++++
 3 files changed, 97 insertions(+)

Comments

Arnd Bergmann July 21, 2013, 8:20 a.m. UTC | #1 
On Sunday 21 July 2013, Domenico Andreoli wrote:
> From: Domenico Andreoli <domenico.andreoli@linux.com>
> 
> Restart hook implementation for the Broadcom BCM4760 based ARM11 SoCs.
> 
> Cc: linux-arm-kernel@lists.infradead.org
> Signed-off-by: Domenico Andreoli <domenico.andreoli@linux.com>
> ---
>  Documentation/devicetree/bindings/watchdog/brcm,bcm4760-pm-wdt.txt |   14 ++
>  arch/arm/boot/dts/bcm4760.dtsi                                     |    5 +
>  arch/arm/mach-bcm/bcm4760.c                                        |   78 ++++++++++
>  3 files changed, 97 insertions(+)

The implementation looks ok to me, but I would prefer this to be part of a
watchdog device driver that overrides the pm_power_off hook.

It can probably be done at a later stage when you submit a watchdog driver.

	Arnd

> Index: b/Documentation/devicetree/bindings/watchdog/brcm,bcm4760-pm-wdt.txt
> ===================================================================
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/watchdog/brcm,bcm4760-pm-wdt.txt
> @@ -0,0 +1,14 @@
> +Broadcom BCM4760 watchdog timer device tree bindings
> +----------------------------------------------------
> +
> +Required properties:
> +
> +- compatible : should be "brcm,bcm4760-pm-wdt"
> +- reg : Specifies base physical address and size of the registers.
> +
> +Example:
> +
> +watchdog {
> +	compatible = "brcm,bcm4760-pm-wdt";
> +	reg = <0xbd000 0x1000>;
> +};
> Index: b/arch/arm/boot/dts/bcm4760.dtsi
> ===================================================================
> --- a/arch/arm/boot/dts/bcm4760.dtsi
> +++ b/arch/arm/boot/dts/bcm4760.dtsi
> @@ -23,6 +23,11 @@
>  			reg = <0xbc000 0x1000>;
>  		};
>  
> +		watchdog {
> +			compatible = "brcm,bcm4760-pm-wdt";
> +			reg = <0xbd000 0x1000>;
> +		};
> +
>  		vic0: interrupt-controller@80000 {
>  			compatible = "brcm,bcm4760-pl192", "arm,pl192-vic", "arm,primecell";
>  			reg = <0x80000 0x1000>;
> Index: b/arch/arm/mach-bcm/bcm4760.c
> ===================================================================
> --- a/arch/arm/mach-bcm/bcm4760.c
> +++ b/arch/arm/mach-bcm/bcm4760.c
> @@ -16,7 +16,9 @@
>  
>  #include <linux/init.h>
>  #include <linux/irqchip.h>
> +#include <linux/delay.h>
>  #include <linux/of_irq.h>
> +#include <linux/of_address.h>
>  #include <linux/of_platform.h>
>  #include <linux/clk/bcm4760.h>
>  
> @@ -28,6 +30,17 @@
>  #define BCM4760_PERIPH_VIRT   IOMEM(0xd0080000)
>  #define BCM4760_PERIPH_SIZE   SZ_512K
>  
> +#define BCM4760_WDT_LOAD      0x000
> +#define BCM4760_WDT_CTRL      0x008
> +#define BCM4760_WDT_INTCLR    0x00c
> +#define BCM4760_WDT_LOCK      0xc00
> +
> +#define BCM4760_WDT_PASSWORD  0x1acce551
> +#define BCM4760_WDT_INTEN     BIT(0)
> +#define BCM4760_WDT_RESEN     BIT(1)
> +
> +static void __iomem *wdt_regs;
> +
>  static struct map_desc io_map __initdata = {
>  	.virtual = (unsigned long) BCM4760_PERIPH_VIRT,
>  	.pfn = __phys_to_pfn(BCM4760_PERIPH_PHYS),
> @@ -56,11 +69,75 @@ static void __init bcm4760_system_rev(vo
>  		system_rev = id0 << 8 | (id1 & 0xff);
>  }
>  
> +static const struct of_device_id bcm4760_pm_wdt_match[] __initconst = {
> +	{ .compatible = "brcm,bcm4760-pm-wdt" },
> +	{}
> +};
> +
> +/*
> + * The machine restart method can be called from an atomic context so we won't
> + * be able to ioremap the regs then.
> + */
> +static void __init bcm4760_setup_restart(void)
> +{
> +	struct device_node *node;
> +
> +	node = of_find_matching_node(NULL, bcm4760_pm_wdt_match);
> +	if (!node) {
> +		pr_info("No bcm4760 watchdog node\n");
> +		return;
> +	}
> +
> +	wdt_regs = of_iomap(node, 0);
> +	if (!wdt_regs) {
> +		pr_err("Can't remap watchdog registers\n");
> +		return;
> +	}
> +
> +	/* unlock watchdog registers */
> +	writel(BCM4760_WDT_PASSWORD, wdt_regs + BCM4760_WDT_LOCK);
> +	/* disable watchdog */
> +	writel(0, wdt_regs + BCM4760_WDT_CTRL);
> +	/* lock watchdog registers */
> +	writel(1, wdt_regs + BCM4760_WDT_LOCK);
> +}
> +
> +static void bcm4760_restart(enum reboot_mode mode, const char *cmd)
> +{
> +	if (!wdt_regs) {
> +		pr_err("No restart hook installed. ");
> +		return;
> +	}
> +
> +	/* unlock watchdog registers */
> +	writel(BCM4760_WDT_PASSWORD, wdt_regs + BCM4760_WDT_LOCK);
> +
> +	/* disable watchdog */
> +	writel(0, wdt_regs + BCM4760_WDT_CTRL);
> +	udelay(20);
> +
> +	/* clear the irq status */
> +	writel(1, wdt_regs + BCM4760_WDT_INTCLR);
> +	udelay(20);
> +
> +	/* expire after 5 cycles (~156us) */
> +	writel(5, wdt_regs + BCM4760_WDT_LOAD);
> +	/* enable watchdog */
> +	writel(BCM4760_WDT_INTEN | BCM4760_WDT_RESEN,
> +		wdt_regs + BCM4760_WDT_CTRL);
> +
> +	/* lock watchdog registers */
> +	writel(1, wdt_regs + BCM4760_WDT_LOCK);
> +	/* wait the bite */
> +	udelay(400);
> +}
> +
>  static void __init bcm4760_init(void)
>  {
>  	int err;
>  
>  	bcm4760_system_rev();
> +	bcm4760_setup_restart();
>  	bcm4760_init_clocks();
>  
>  	err = of_platform_populate(NULL, of_default_bus_match_table, NULL, NULL);
> @@ -78,5 +155,6 @@ static const char * const bcm4760_compat
>  DT_MACHINE_START(BCM4760, "Broadcom BCM4760")
>  	.map_io = bcm4760_map_io,
>  	.init_machine = bcm4760_init,
> +	.restart = bcm4760_restart,
>  	.dt_compat = bcm4760_compat
>  MACHINE_END
> 
>
Domenico Andreoli July 22, 2013, 9:14 p.m. UTC | #2 
On Sun, Jul 21, 2013 at 10:20:25AM +0200, Arnd Bergmann wrote:
> On Sunday 21 July 2013, Domenico Andreoli wrote:
> > From: Domenico Andreoli <domenico.andreoli@linux.com>
> > 
> > Restart hook implementation for the Broadcom BCM4760 based ARM11 SoCs.
> > 
> > Cc: linux-arm-kernel@lists.infradead.org
> > Signed-off-by: Domenico Andreoli <domenico.andreoli@linux.com>
> > ---
> >  Documentation/devicetree/bindings/watchdog/brcm,bcm4760-pm-wdt.txt |   14 ++
> >  arch/arm/boot/dts/bcm4760.dtsi                                     |    5 +
> >  arch/arm/mach-bcm/bcm4760.c                                        |   78 ++++++++++
> >  3 files changed, 97 insertions(+)
> 
> The implementation looks ok to me, but I would prefer this to be part of a
> watchdog device driver that overrides the pm_power_off hook.

I'd appreciate if I could keep this implementation, which I don't plan to
develop further, but won't cry if it's left out.

> It can probably be done at a later stage when you submit a watchdog driver.

I should be able to reuse an existing ARM watchdog driver but I need to
investigate further.

BTW is it acceptable to loose the ability to reboot the board in case the
proper watchdog driver is not configured?

Domenico

> 
> 	Arnd
> 
> > Index: b/Documentation/devicetree/bindings/watchdog/brcm,bcm4760-pm-wdt.txt
> > ===================================================================
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/watchdog/brcm,bcm4760-pm-wdt.txt
> > @@ -0,0 +1,14 @@
> > +Broadcom BCM4760 watchdog timer device tree bindings
> > +----------------------------------------------------
> > +
> > +Required properties:
> > +
> > +- compatible : should be "brcm,bcm4760-pm-wdt"
> > +- reg : Specifies base physical address and size of the registers.
> > +
> > +Example:
> > +
> > +watchdog {
> > +	compatible = "brcm,bcm4760-pm-wdt";
> > +	reg = <0xbd000 0x1000>;
> > +};
> > Index: b/arch/arm/boot/dts/bcm4760.dtsi
> > ===================================================================
> > --- a/arch/arm/boot/dts/bcm4760.dtsi
> > +++ b/arch/arm/boot/dts/bcm4760.dtsi
> > @@ -23,6 +23,11 @@
> >  			reg = <0xbc000 0x1000>;
> >  		};
> >  
> > +		watchdog {
> > +			compatible = "brcm,bcm4760-pm-wdt";
> > +			reg = <0xbd000 0x1000>;
> > +		};
> > +
> >  		vic0: interrupt-controller@80000 {
> >  			compatible = "brcm,bcm4760-pl192", "arm,pl192-vic", "arm,primecell";
> >  			reg = <0x80000 0x1000>;
> > Index: b/arch/arm/mach-bcm/bcm4760.c
> > ===================================================================
> > --- a/arch/arm/mach-bcm/bcm4760.c
> > +++ b/arch/arm/mach-bcm/bcm4760.c
> > @@ -16,7 +16,9 @@
> >  
> >  #include <linux/init.h>
> >  #include <linux/irqchip.h>
> > +#include <linux/delay.h>
> >  #include <linux/of_irq.h>
> > +#include <linux/of_address.h>
> >  #include <linux/of_platform.h>
> >  #include <linux/clk/bcm4760.h>
> >  
> > @@ -28,6 +30,17 @@
> >  #define BCM4760_PERIPH_VIRT   IOMEM(0xd0080000)
> >  #define BCM4760_PERIPH_SIZE   SZ_512K
> >  
> > +#define BCM4760_WDT_LOAD      0x000
> > +#define BCM4760_WDT_CTRL      0x008
> > +#define BCM4760_WDT_INTCLR    0x00c
> > +#define BCM4760_WDT_LOCK      0xc00
> > +
> > +#define BCM4760_WDT_PASSWORD  0x1acce551
> > +#define BCM4760_WDT_INTEN     BIT(0)
> > +#define BCM4760_WDT_RESEN     BIT(1)
> > +
> > +static void __iomem *wdt_regs;
> > +
> >  static struct map_desc io_map __initdata = {
> >  	.virtual = (unsigned long) BCM4760_PERIPH_VIRT,
> >  	.pfn = __phys_to_pfn(BCM4760_PERIPH_PHYS),
> > @@ -56,11 +69,75 @@ static void __init bcm4760_system_rev(vo
> >  		system_rev = id0 << 8 | (id1 & 0xff);
> >  }
> >  
> > +static const struct of_device_id bcm4760_pm_wdt_match[] __initconst = {
> > +	{ .compatible = "brcm,bcm4760-pm-wdt" },
> > +	{}
> > +};
> > +
> > +/*
> > + * The machine restart method can be called from an atomic context so we won't
> > + * be able to ioremap the regs then.
> > + */
> > +static void __init bcm4760_setup_restart(void)
> > +{
> > +	struct device_node *node;
> > +
> > +	node = of_find_matching_node(NULL, bcm4760_pm_wdt_match);
> > +	if (!node) {
> > +		pr_info("No bcm4760 watchdog node\n");
> > +		return;
> > +	}
> > +
> > +	wdt_regs = of_iomap(node, 0);
> > +	if (!wdt_regs) {
> > +		pr_err("Can't remap watchdog registers\n");
> > +		return;
> > +	}
> > +
> > +	/* unlock watchdog registers */
> > +	writel(BCM4760_WDT_PASSWORD, wdt_regs + BCM4760_WDT_LOCK);
> > +	/* disable watchdog */
> > +	writel(0, wdt_regs + BCM4760_WDT_CTRL);
> > +	/* lock watchdog registers */
> > +	writel(1, wdt_regs + BCM4760_WDT_LOCK);
> > +}
> > +
> > +static void bcm4760_restart(enum reboot_mode mode, const char *cmd)
> > +{
> > +	if (!wdt_regs) {
> > +		pr_err("No restart hook installed. ");
> > +		return;
> > +	}
> > +
> > +	/* unlock watchdog registers */
> > +	writel(BCM4760_WDT_PASSWORD, wdt_regs + BCM4760_WDT_LOCK);
> > +
> > +	/* disable watchdog */
> > +	writel(0, wdt_regs + BCM4760_WDT_CTRL);
> > +	udelay(20);
> > +
> > +	/* clear the irq status */
> > +	writel(1, wdt_regs + BCM4760_WDT_INTCLR);
> > +	udelay(20);
> > +
> > +	/* expire after 5 cycles (~156us) */
> > +	writel(5, wdt_regs + BCM4760_WDT_LOAD);
> > +	/* enable watchdog */
> > +	writel(BCM4760_WDT_INTEN | BCM4760_WDT_RESEN,
> > +		wdt_regs + BCM4760_WDT_CTRL);
> > +
> > +	/* lock watchdog registers */
> > +	writel(1, wdt_regs + BCM4760_WDT_LOCK);
> > +	/* wait the bite */
> > +	udelay(400);
> > +}
> > +
> >  static void __init bcm4760_init(void)
> >  {
> >  	int err;
> >  
> >  	bcm4760_system_rev();
> > +	bcm4760_setup_restart();
> >  	bcm4760_init_clocks();
> >  
> >  	err = of_platform_populate(NULL, of_default_bus_match_table, NULL, NULL);
> > @@ -78,5 +155,6 @@ static const char * const bcm4760_compat
> >  DT_MACHINE_START(BCM4760, "Broadcom BCM4760")
> >  	.map_io = bcm4760_map_io,
> >  	.init_machine = bcm4760_init,
> > +	.restart = bcm4760_restart,
> >  	.dt_compat = bcm4760_compat
> >  MACHINE_END
> > 
> > 
> 
> 
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
diff mbox

Patch

Index: b/Documentation/devicetree/bindings/watchdog/brcm,bcm4760-pm-wdt.txt
===================================================================
--- /dev/null
+++ b/Documentation/devicetree/bindings/watchdog/brcm,bcm4760-pm-wdt.txt
@@ -0,0 +1,14 @@ 
+Broadcom BCM4760 watchdog timer device tree bindings
+----------------------------------------------------
+
+Required properties:
+
+- compatible : should be "brcm,bcm4760-pm-wdt"
+- reg : Specifies base physical address and size of the registers.
+
+Example:
+
+watchdog {
+	compatible = "brcm,bcm4760-pm-wdt";
+	reg = <0xbd000 0x1000>;
+};
Index: b/arch/arm/boot/dts/bcm4760.dtsi
===================================================================
--- a/arch/arm/boot/dts/bcm4760.dtsi
+++ b/arch/arm/boot/dts/bcm4760.dtsi
@@ -23,6 +23,11 @@ 
 			reg = <0xbc000 0x1000>;
 		};
 
+		watchdog {
+			compatible = "brcm,bcm4760-pm-wdt";
+			reg = <0xbd000 0x1000>;
+		};
+
 		vic0: interrupt-controller@80000 {
 			compatible = "brcm,bcm4760-pl192", "arm,pl192-vic", "arm,primecell";
 			reg = <0x80000 0x1000>;
Index: b/arch/arm/mach-bcm/bcm4760.c
===================================================================
--- a/arch/arm/mach-bcm/bcm4760.c
+++ b/arch/arm/mach-bcm/bcm4760.c
@@ -16,7 +16,9 @@ 
 
 #include <linux/init.h>
 #include <linux/irqchip.h>
+#include <linux/delay.h>
 #include <linux/of_irq.h>
+#include <linux/of_address.h>
 #include <linux/of_platform.h>
 #include <linux/clk/bcm4760.h>
 
@@ -28,6 +30,17 @@ 
 #define BCM4760_PERIPH_VIRT   IOMEM(0xd0080000)
 #define BCM4760_PERIPH_SIZE   SZ_512K
 
+#define BCM4760_WDT_LOAD      0x000
+#define BCM4760_WDT_CTRL      0x008
+#define BCM4760_WDT_INTCLR    0x00c
+#define BCM4760_WDT_LOCK      0xc00
+
+#define BCM4760_WDT_PASSWORD  0x1acce551
+#define BCM4760_WDT_INTEN     BIT(0)
+#define BCM4760_WDT_RESEN     BIT(1)
+
+static void __iomem *wdt_regs;
+
 static struct map_desc io_map __initdata = {
 	.virtual = (unsigned long) BCM4760_PERIPH_VIRT,
 	.pfn = __phys_to_pfn(BCM4760_PERIPH_PHYS),
@@ -56,11 +69,75 @@  static void __init bcm4760_system_rev(vo
 		system_rev = id0 << 8 | (id1 & 0xff);
 }
 
+static const struct of_device_id bcm4760_pm_wdt_match[] __initconst = {
+	{ .compatible = "brcm,bcm4760-pm-wdt" },
+	{}
+};
+
+/*
+ * The machine restart method can be called from an atomic context so we won't
+ * be able to ioremap the regs then.
+ */
+static void __init bcm4760_setup_restart(void)
+{
+	struct device_node *node;
+
+	node = of_find_matching_node(NULL, bcm4760_pm_wdt_match);
+	if (!node) {
+		pr_info("No bcm4760 watchdog node\n");
+		return;
+	}
+
+	wdt_regs = of_iomap(node, 0);
+	if (!wdt_regs) {
+		pr_err("Can't remap watchdog registers\n");
+		return;
+	}
+
+	/* unlock watchdog registers */
+	writel(BCM4760_WDT_PASSWORD, wdt_regs + BCM4760_WDT_LOCK);
+	/* disable watchdog */
+	writel(0, wdt_regs + BCM4760_WDT_CTRL);
+	/* lock watchdog registers */
+	writel(1, wdt_regs + BCM4760_WDT_LOCK);
+}
+
+static void bcm4760_restart(enum reboot_mode mode, const char *cmd)
+{
+	if (!wdt_regs) {
+		pr_err("No restart hook installed. ");
+		return;
+	}
+
+	/* unlock watchdog registers */
+	writel(BCM4760_WDT_PASSWORD, wdt_regs + BCM4760_WDT_LOCK);
+
+	/* disable watchdog */
+	writel(0, wdt_regs + BCM4760_WDT_CTRL);
+	udelay(20);
+
+	/* clear the irq status */
+	writel(1, wdt_regs + BCM4760_WDT_INTCLR);
+	udelay(20);
+
+	/* expire after 5 cycles (~156us) */
+	writel(5, wdt_regs + BCM4760_WDT_LOAD);
+	/* enable watchdog */
+	writel(BCM4760_WDT_INTEN | BCM4760_WDT_RESEN,
+		wdt_regs + BCM4760_WDT_CTRL);
+
+	/* lock watchdog registers */
+	writel(1, wdt_regs + BCM4760_WDT_LOCK);
+	/* wait the bite */
+	udelay(400);
+}
+
 static void __init bcm4760_init(void)
 {
 	int err;
 
 	bcm4760_system_rev();
+	bcm4760_setup_restart();
 	bcm4760_init_clocks();
 
 	err = of_platform_populate(NULL, of_default_bus_match_table, NULL, NULL);
@@ -78,5 +155,6 @@  static const char * const bcm4760_compat
 DT_MACHINE_START(BCM4760, "Broadcom BCM4760")
 	.map_io = bcm4760_map_io,
 	.init_machine = bcm4760_init,
+	.restart = bcm4760_restart,
 	.dt_compat = bcm4760_compat
 MACHINE_END