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

[Ezequiel Garcia <ezequiel.garcia-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>]

On Sat, Jan 25, 2014 at 10:19:42AM -0800, Guenter Roeck wrote:
> 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-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>
> > ---
> >   .../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-0h96xk9xTtrk1uMJSBkQmQ@public.gmane.org>
> 

Yes, it's on purpose. We want users to notice this and be aware they have
a broken dtb (hence the sign firmware bug).
-- 
Ezequiel García, Free Electrons
Embedded Linux, Kernel and Android Engineering
http://free-electrons.com
--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html