[RFC PATCH 0/4] watchdog: at91sam9_wdt: handle already configured wdt

[Yang, Wenyou]

> -----Original Message-----
> From: linux-arm-kernel [mailto:linux-arm-kernel-bounces at lists.infradead.org]
> On Behalf Of Boris BREZILLON
> Sent: 2013年6月11日 18:51
> To: Wim Van Sebroeck; Jean-Christophe Plagniol-Villard; Ferre, Nicolas;
> linux-watchdog at vger.kernel.org
> Cc: devicetree-discuss at lists.ozlabs.org; linux-doc at vger.kernel.org;
> linux-kernel at vger.kernel.org; linux-arm-kernel at lists.infradead.org; Boris
> BREZILLON
> Subject: [RFC PATCH 0/4] watchdog: at91sam9_wdt: handle already configured
> wdt
> 
> Hello,
> 
> This patch series is a porposal to enhance the sam9 watchdog timer support.
> 
> The at91sam9 watchdog timer cannot configured twice, and the current
> implementation only tries to configure in a static way:
> - 2 seconds timeout
> - wdt restart every 500ms
> 
> If the timer has already been configured with different values, it returns an
> error and do not create any watchdog device.
> 
> This is not critical if the watchdog is disabled, but if it has been enabled with
> different timeout values it will lead to a SoC reset.
> 
> This patch series tries to address this issue by adapting the heartbeat value
> according the WDT timer config:
> - it first tries to configure the timer as requested.
> - if it fails it fallbacks to the current config, adapting its heartbeat timer
> to the needs
> 
> This patch series also move to a dynamically allocated at91wdt device instead
> of the static instance. I'm not sure this is the best solution, so please tell
> me if you prefer to keep static instance of watchdog.
> 
> It adds a new at91 wdt type: software. This new type make use of the at91 wdt
> interrupt to trigger a software watchdog.
> 
> Finally it adds several properties to the device tree bindings.
> 
> Best Regards,
> Boris
> 
> Boris BREZILLON (4):
>   watchdog: at91sam9_wdt: better watchdog support
>   watchdog: at91sam9_wdt: update device tree doc
>   ARM: at91/dt: add sam9 watchdog default options to SoCs
>   ARM: at91/dt: add watchdog properties to kizbox board
> 
>  .../devicetree/bindings/watchdog/atmel-wdt.txt     |   30 +-
>  arch/arm/boot/dts/at91sam9260.dtsi                 |    5 +
>  arch/arm/boot/dts/at91sam9263.dtsi                 |    5 +
>  arch/arm/boot/dts/at91sam9g45.dtsi                 |    5 +
>  arch/arm/boot/dts/at91sam9n12.dtsi                 |    5 +
>  arch/arm/boot/dts/at91sam9x5.dtsi                  |    5 +
>  arch/arm/boot/dts/kizbox.dts                       |    6 +
>  arch/arm/boot/dts/sama5d3.dtsi                     |    5 +
>  drivers/watchdog/at91sam9_wdt.c                    |  319
> +++++++++++++++-----
>  9 files changed, 300 insertions(+), 85 deletions(-)
> 
> --
> 1.7.9.5
> 
> 
Tested on sama5d34ek, at91sam9g25ek, linux-next_20130620

Tested by Wenyou Yang <Wenyou.yang at atmel.com>


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