Re: [PATCH v4 08/18] watchdog: orion: Make RSTOUT register a separate resource

[Guenter Roeck <linux@roeck-us.net>]

On 01/22/2014 03:05 PM, Ezequiel Garcia wrote:
> In order to support other SoC, it's required to distinguish
> the 'control' timer register, from the 'rstout' register
> that enables system reset on watchdog expiration.
>
> To prevent a compatibility break, this commit adds a fallback
> to a hardcoded RSTOUT address.
>
> Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
> ---
>   .../devicetree/bindings/watchdog/marvel.txt        |  6 ++-
>   arch/arm/mach-dove/include/mach/bridge-regs.h      |  1 +
>   arch/arm/mach-kirkwood/include/mach/bridge-regs.h  |  1 +
>   arch/arm/mach-mv78xx0/include/mach/bridge-regs.h   |  1 +
>   arch/arm/mach-orion5x/include/mach/bridge-regs.h   |  1 +
>   arch/arm/plat-orion/common.c                       | 10 +++--
>   drivers/watchdog/orion_wdt.c                       | 44 +++++++++++++++++++++-
>   7 files changed, 56 insertions(+), 8 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/watchdog/marvel.txt b/Documentation/devicetree/bindings/watchdog/marvel.txt
> index 0731fbd..1544fe9 100644
> --- a/Documentation/devicetree/bindings/watchdog/marvel.txt
> +++ b/Documentation/devicetree/bindings/watchdog/marvel.txt
> @@ -3,7 +3,9 @@
>   Required Properties:
>
>   - Compatibility : "marvell,orion-wdt"
> -- reg		: Address of the timer registers
> +- reg		: Should contain two entries: first one with the
> +		  timer control address, second one with the
> +		  rstout enable address.
>
>   Optional properties:
>
> @@ -14,7 +16,7 @@ Example:
>
>   	wdt@20300 {
>   		compatible = "marvell,orion-wdt";
> -		reg = <0x20300 0x28>;
> +		reg = <0x20300 0x28>, <0x20108 0x4>;
>   		interrupts = <3>;
>   		timeout-sec = <10>;
>   		status = "okay";
> diff --git a/arch/arm/mach-dove/include/mach/bridge-regs.h b/arch/arm/mach-dove/include/mach/bridge-regs.h
> index 5362df3..f4a5b34 100644
> --- a/arch/arm/mach-dove/include/mach/bridge-regs.h
> +++ b/arch/arm/mach-dove/include/mach/bridge-regs.h
> @@ -21,6 +21,7 @@
>   #define  CPU_CTRL_PCIE1_LINK	0x00000008
>
>   #define RSTOUTn_MASK		(BRIDGE_VIRT_BASE + 0x0108)
> +#define RSTOUTn_MASK_PHYS	(BRIDGE_PHYS_BASE + 0x0108)
>   #define  SOFT_RESET_OUT_EN	0x00000004
>
>   #define SYSTEM_SOFT_RESET	(BRIDGE_VIRT_BASE + 0x010c)
> diff --git a/arch/arm/mach-kirkwood/include/mach/bridge-regs.h b/arch/arm/mach-kirkwood/include/mach/bridge-regs.h
> index 8b9d1c9..60f6421 100644
> --- a/arch/arm/mach-kirkwood/include/mach/bridge-regs.h
> +++ b/arch/arm/mach-kirkwood/include/mach/bridge-regs.h
> @@ -21,6 +21,7 @@
>   #define CPU_RESET		0x00000002
>
>   #define RSTOUTn_MASK		(BRIDGE_VIRT_BASE + 0x0108)
> +#define RSTOUTn_MASK_PHYS	(BRIDGE_PHYS_BASE + 0x0108)
>   #define SOFT_RESET_OUT_EN	0x00000004
>
>   #define SYSTEM_SOFT_RESET	(BRIDGE_VIRT_BASE + 0x010c)
> diff --git a/arch/arm/mach-mv78xx0/include/mach/bridge-regs.h b/arch/arm/mach-mv78xx0/include/mach/bridge-regs.h
> index 5f03484..e20d6da 100644
> --- a/arch/arm/mach-mv78xx0/include/mach/bridge-regs.h
> +++ b/arch/arm/mach-mv78xx0/include/mach/bridge-regs.h
> @@ -15,6 +15,7 @@
>   #define L2_WRITETHROUGH		0x00020000
>
>   #define RSTOUTn_MASK		(BRIDGE_VIRT_BASE + 0x0108)
> +#define RSTOUTn_MASK_PHYS	(BRIDGE_PHYS_BASE + 0x0108)
>   #define SOFT_RESET_OUT_EN	0x00000004
>
>   #define SYSTEM_SOFT_RESET	(BRIDGE_VIRT_BASE + 0x010c)
> diff --git a/arch/arm/mach-orion5x/include/mach/bridge-regs.h b/arch/arm/mach-orion5x/include/mach/bridge-regs.h
> index f727d03..5766e3f 100644
> --- a/arch/arm/mach-orion5x/include/mach/bridge-regs.h
> +++ b/arch/arm/mach-orion5x/include/mach/bridge-regs.h
> @@ -18,6 +18,7 @@
>   #define CPU_CTRL		(ORION5X_BRIDGE_VIRT_BASE + 0x104)
>
>   #define RSTOUTn_MASK		(ORION5X_BRIDGE_VIRT_BASE + 0x108)
> +#define RSTOUTn_MASK_PHYS	(ORION5X_BRIDGE_PHYS_BASE + 0x108)
>
>   #define CPU_SOFT_RESET		(ORION5X_BRIDGE_VIRT_BASE + 0x10c)
>
> diff --git a/arch/arm/plat-orion/common.c b/arch/arm/plat-orion/common.c
> index c66d163..3375037 100644
> --- a/arch/arm/plat-orion/common.c
> +++ b/arch/arm/plat-orion/common.c
> @@ -594,14 +594,16 @@ void __init orion_spi_1_init(unsigned long mapbase)
>   /*****************************************************************************
>    * Watchdog
>    ****************************************************************************/
> -static struct resource orion_wdt_resource =
> -		DEFINE_RES_MEM(TIMER_PHYS_BASE, 0x28);
> +static struct resource orion_wdt_resource[] = {
> +		DEFINE_RES_MEM(TIMER_PHYS_BASE, 0x04),
> +		DEFINE_RES_MEM(RSTOUTn_MASK_PHYS, 0x04),
> +};
>
>   static struct platform_device orion_wdt_device = {
>   	.name		= "orion_wdt",
>   	.id		= -1,
> -	.num_resources	= 1,
> -	.resource	= &orion_wdt_resource,
> +	.num_resources	= ARRAY_SIZE(orion_wdt_resource),
> +	.resource	= orion_wdt_resource,
>   };
>
>   void __init orion_wdt_init(void)
> diff --git a/drivers/watchdog/orion_wdt.c b/drivers/watchdog/orion_wdt.c
> index f5e7b17..ba8eea9d 100644
> --- a/drivers/watchdog/orion_wdt.c
> +++ b/drivers/watchdog/orion_wdt.c
> @@ -26,6 +26,12 @@
>   #include <linux/of.h>
>   #include <mach/bridge-regs.h>
>
> +/* RSTOUT mask register physical address for Orion5x, Kirkwood and Dove */
> +#define ORION_RSTOUT_MASK_OFFSET	0x20108
> +
> +/* Internal registers can be configured at any 1 MiB aligned address */
> +#define INTERNAL_REGS_MASK		~(SZ_1M - 1)
> +
>   /*
>    * Watchdog timer block registers.
>    */
> @@ -44,6 +50,7 @@ static unsigned int wdt_max_duration;	/* (seconds) */
>   static struct clk *clk;
>   static unsigned int wdt_tclk;
>   static void __iomem *wdt_reg;
> +static void __iomem *wdt_rstout;
>
>   static int orion_wdt_ping(struct watchdog_device *wdt_dev)
>   {
> @@ -64,14 +71,14 @@ static int orion_wdt_start(struct watchdog_device *wdt_dev)
>   	atomic_io_modify(wdt_reg + TIMER_CTRL, WDT_EN, WDT_EN);
>
>   	/* Enable reset on watchdog */
> -	atomic_io_modify(RSTOUTn_MASK, WDT_RESET_OUT_EN, WDT_RESET_OUT_EN);
> +	atomic_io_modify(wdt_rstout, WDT_RESET_OUT_EN, WDT_RESET_OUT_EN);
>   	return 0;
>   }
>
>   static int orion_wdt_stop(struct watchdog_device *wdt_dev)
>   {
>   	/* Disable reset on watchdog */
> -	atomic_io_modify(RSTOUTn_MASK, WDT_RESET_OUT_EN, 0);
> +	atomic_io_modify(wdt_rstout, WDT_RESET_OUT_EN, 0);
>
>   	/* Disable watchdog timer */
>   	atomic_io_modify(wdt_reg + TIMER_CTRL, WDT_EN, 0);
> @@ -116,6 +123,33 @@ static irqreturn_t orion_wdt_irq(int irq, void *devid)
>   	return IRQ_HANDLED;
>   }
>
> +/*
> + * The original devicetree binding for this driver specified only
> + * one memory resource, so in order to keep DT backwards compatibility
> + * we try to fallback to a hardcoded register address, if the resource
> + * is missing from the devicetree.
> + */
> +static void __iomem *try_rstout_ioremap(struct platform_device *pdev,
> +					phys_addr_t internal_regs)
> +{
> +	struct resource *res;
> +	phys_addr_t rstout;
> +
> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
> +	if (res)
> +		return devm_ioremap(&pdev->dev, res->start,
> +				    resource_size(res));
> +
> +	/* This workaround works only for "orion-wdt", DT-enabled */
> +	if (!of_device_is_compatible(pdev->dev.of_node, "marvell,orion-wdt"))
> +		return NULL;
> +
> +	rstout = internal_regs + ORION_RSTOUT_MASK_OFFSET;
> +
> +	WARN(1, FW_BUG "falling back to harcoded RSTOUT reg 0x%x\n", rstout);

WARN seems to be a bit excessive here. Is that on purpose (sorry if that was discussed and I missed it) ?

Assuming it is on purpose

Reviewed-by: Guenter Roeck <linux@roeck-us.net>