[PATCH v6 3/5] watchdog: at91sam9_wdt: add device tree support

[Fabio Porcedda]

On Mon, Oct 1, 2012 at 3:06 PM, Andrew Lunn <andrew at lunn.ch> wrote:
> On Mon, Oct 01, 2012 at 02:54:55PM +0200, Fabio Porcedda wrote:
>> On Mon, Oct 1, 2012 at 2:48 PM, Fabio Porcedda <fabio.porcedda at gmail.com> wrote:
>> > On Mon, Oct 1, 2012 at 2:45 PM, Andrew Lunn <andrew at lunn.ch> wrote:
>> >> On Mon, Oct 01, 2012 at 02:24:39PM +0200, Fabio Porcedda wrote:
>> >>> Tested on an at91sam9260 board (evk-pro3)
>> >>>
>> >>> Signed-off-by: Fabio Porcedda <fabio.porcedda at gmail.com>
>> >>> ---
>> >>>  .../devicetree/bindings/watchdog/atmel-wdt.txt      | 19 +++++++++++++++++++
>> >>>  drivers/watchdog/at91sam9_wdt.c                     | 21 +++++++++++++++++++++
>> >>>  2 files changed, 40 insertions(+)
>> >>>  create mode 100644 Documentation/devicetree/bindings/watchdog/atmel-wdt.txt
>> >>>
>> >>> diff --git a/Documentation/devicetree/bindings/watchdog/atmel-wdt.txt b/Documentation/devicetree/bindings/watchdog/atmel-wdt.txt
>> >>> new file mode 100644
>> >>> index 0000000..65c1755
>> >>> --- /dev/null
>> >>> +++ b/Documentation/devicetree/bindings/watchdog/atmel-wdt.txt
>> >>> @@ -0,0 +1,19 @@
>> >>> +* Atmel Watchdog Timers
>> >>> +
>> >>> +** at91sam9-wdt
>> >>> +
>> >>> +Required properties:
>> >>> +- compatible: must be "atmel,at91sam9260-wdt".
>> >>> +- reg: physical base address of the controller and length of memory mapped
>> >>> +  region.
>> >>> +
>> >>> +Optional properties:
>> >>> +- timeout: contains the watchdog timeout in seconds.
>> >>> +
>> >>> +Example:
>> >>> +
>> >>> +     watchdog at fffffd40 {
>> >>> +             compatible = "atmel,at91sam9260-wdt";
>> >>> +             reg = <0xfffffd40 0x10>;
>> >>> +             timeout = <10>;
>> >>> +     };
>> >>> diff --git a/drivers/watchdog/at91sam9_wdt.c b/drivers/watchdog/at91sam9_wdt.c
>> >>> index 05e1be8..c9e6bfa 100644
>> >>> --- a/drivers/watchdog/at91sam9_wdt.c
>> >>> +++ b/drivers/watchdog/at91sam9_wdt.c
>> >>> @@ -32,6 +32,7 @@
>> >>>  #include <linux/timer.h>
>> >>>  #include <linux/bitops.h>
>> >>>  #include <linux/uaccess.h>
>> >>> +#include <linux/of.h>
>> >>>
>> >>>  #include "at91sam9_wdt.h"
>> >>>
>> >>> @@ -254,6 +255,14 @@ static struct miscdevice at91wdt_miscdev = {
>> >>>       .fops           = &at91wdt_fops,
>> >>>  };
>> >>>
>> >>> +static inline void __init at91wdt_probe_dt(struct device_node *node)
>> >>> +{
>> >>> +     if (!node)
>> >>> +             return;
>> >>> +
>> >>> +     of_property_read_u32(node, "timeout", &heartbeat);
>> >>> +}
>> >>> +
>> >>
>> >> In patch #1 you add a function to do this, and then you don't make use
>> >> of it here ?
>> >>
>> >> Or am i missing something?
>> >
>> > I'm using it on the patch #2 for the orion_wdt driver.
>> > Do you think it's better to join the #1 and the #2 patch?
>> >
>> > Best regards
>> > --
>> > Fabio Porcedda
>>
>> I'm sorry, only now i understand your question.
>> The at91sam9_wdt driver don't use the watchdog core framework si i
>> can't use that function cleanly.
>
>> The patch #1 and #2 are for introducing the same property as the
>> at91sam9_wdt driver.
>
> So maybe split this up into two different patchsets. One patchset to
> add the helper function, and the use of this helper to all watchdog
> divers that can use it. I think the following drivers should be
> modified:
>
> orion_wdt.c
> pnx4008_wdt.c
> s3c2410_wdt.c
>
> In a second patchset, convert the AT91SAM9 driver over to the watchdog
> core framework, and then use the helper function.

I was thinking to add a more generic helper function like this:

static inline void watchdog_get_dttimeout(struct device_node *node,
u32 *timeout)
{
	if (node)
		of_property_read_u32(node, "timeout", &wdd->timeout);
}

This way i can use this helper function in the at91sam9_wdt driver too.
What do you think?

Best regards
-- 
Fabio Porcedda