Re: [PATCH V2] watchdog: mpcore: Add DT probing support for ARM mpcore watchdog

[Marc Zyngier <marc.zyngier@arm.com>]

On 21/04/12 12:41, Viresh Kumar wrote:
> This patch adds Device tree probing support for ARM Mpcore watchdog. Its binding
> were already documented in Documentation/devicetree/bindings/arm/twd.txt.
> 
> Signed-off-by: Viresh Kumar <viresh.kumar@st.com>
> ---
> V1->V2:
> - Reuse earlier bindings defined in twd.txt
> 
>  drivers/watchdog/mpcore_wdt.c |   12 ++++++++++++
>  1 files changed, 12 insertions(+), 0 deletions(-)
> 
> diff --git a/drivers/watchdog/mpcore_wdt.c b/drivers/watchdog/mpcore_wdt.c
> index 7c00455..98df379 100644
> --- a/drivers/watchdog/mpcore_wdt.c
> +++ b/drivers/watchdog/mpcore_wdt.c
> @@ -27,6 +27,7 @@
>  #include <linux/io.h>
>  #include <linux/module.h>
>  #include <linux/moduleparam.h>
> +#include <linux/of.h>
>  #include <linux/platform_device.h>
>  #include <linux/pm.h>
>  #include <linux/reboot.h>
> @@ -402,6 +403,16 @@ static SIMPLE_DEV_PM_OPS(mpcore_wdt_dev_pm_ops, mpcore_wdt_suspend,
>  /* work with hotplug and coldplug */
>  MODULE_ALIAS("platform:mpcore_wdt");
>  
> +#ifdef CONFIG_OF
> +static const struct of_device_id mpcore_wdt_id_table[] = {
> +	{ .compatible = "arm,cortex-a9-twd-wdt" },
> +	{ .compatible = "arm,cortex-a5-twd-wdt" },
> +	{ .compatible = "arm,arm11mp-twd-wdt" },
> +	{}
> +};
> +MODULE_DEVICE_TABLE(of, mpcore_wdt_id_table);
> +#endif
> +
>  static struct platform_driver mpcore_wdt_driver = {
>  	.probe		= mpcore_wdt_probe,
>  	.remove		= __devexit_p(mpcore_wdt_remove),
> @@ -410,6 +421,7 @@ static struct platform_driver mpcore_wdt_driver = {
>  		.owner	= THIS_MODULE,
>  		.name	= "mpcore_wdt",
>  		.pm	= &mpcore_wdt_dev_pm_ops,
> +		.of_match_table = of_match_ptr(mpcore_wdt_id_table),
>  	},
>  };
>  

Irk! Have you actually tested this?

The DT binding indicates:
- reg : Specify the base address and the size of the TWD watchdog
        register window.

while all the offsets in smp_twd.h are expressed in bytes from the TWD
*timer* base. So you have to either fix these offsets (which breaks
potential users of the non-DT version of the driver), or correct the
base when using DT.

	M.
-- 
Jazz is not dead. It just smells funny...

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