[PATCH v2 1/3] power: reset: read priority from device tree

Feng Kan fkan at apm.com
Mon Dec 1 09:38:09 PST 2014


On Mon, Dec 1, 2014 at 9:29 AM, Stefan Agner <stefan at agner.ch> wrote:
> On 2014-12-01 18:15, Feng Kan wrote:
>> On Mon, Dec 1, 2014 at 9:03 AM, Stefan Agner <stefan at agner.ch> wrote:
>>> This patch adds an optional property which allows to specify the
>>> reset source priority. This priority is used by the kernel restart
>>> handler call chain to sort out the proper reset/restart method.
>>> Depending on the power design of a board or other machine/board
>>> specific peculiarity, it is not possible to pick a generic priority.
>>>
>>> Signed-off-by: Stefan Agner <stefan at agner.ch>
>>> ---
>>>  Documentation/devicetree/bindings/power/reset/syscon-reboot.txt | 3 +++
>>>  drivers/power/reset/syscon-reboot.c                             | 5 ++++-
>>>  2 files changed, 7 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/Documentation/devicetree/bindings/power/reset/syscon-reboot.txt b/Documentation/devicetree/bindings/power/reset/syscon-reboot.txt
>>> index 1190631..ee41d9c 100644
>>> --- a/Documentation/devicetree/bindings/power/reset/syscon-reboot.txt
>>> +++ b/Documentation/devicetree/bindings/power/reset/syscon-reboot.txt
>>> @@ -11,6 +11,9 @@ Required properties:
>>>  - offset: offset in the register map for the reboot register (in bytes)
>>>  - mask: the reset value written to the reboot register (32 bit access)
>>>
>>> +Optional properties:
>>> +- priority: define the priority of the reset (0-255, defaults to 128)
>>> +
>>>  Default will be little endian mode, 32 bit access only.
>>>
>>>  Examples:
>>> diff --git a/drivers/power/reset/syscon-reboot.c b/drivers/power/reset/syscon-reboot.c
>>> index 815b901..3060d6b 100644
>>> --- a/drivers/power/reset/syscon-reboot.c
>>> +++ b/drivers/power/reset/syscon-reboot.c
>>> @@ -67,8 +67,11 @@ static int syscon_reboot_probe(struct platform_device *pdev)
>>>         if (of_property_read_u32(pdev->dev.of_node, "mask", &ctx->mask))
>>>                 return -EINVAL;
>>>
>>> -       ctx->restart_handler.notifier_call = syscon_restart_handle;
>>>         ctx->restart_handler.priority = 128;
>>> +       of_property_read_u32(pdev->dev.of_node, "priority",
>>> +                            &ctx->restart_handler.priority);
>>
>> What is this for?
>
> What do you mean? The moved line "ctx->restart_handler.notifier_call =
> syscon_restart_handle;"? When one reads the diff, it looks like that
> line was moved, in fact I tried to keep the of_property_read function
> calls together. But I had to move the assignation of the default
> priority in front of restart_handler.priority. That's what is the
> outcome...

I believe Guenter explained above already. Actually this help to solve one of
my problem. Thanks.
>
> --
> Stefan
>
>>> +
>>> +       ctx->restart_handler.notifier_call = syscon_restart_handle;
>>>         err = register_restart_handler(&ctx->restart_handler);
>>>         if (err)
>>>                 dev_err(dev, "can't register restart notifier (err=%d)\n", err);
>>> --
>>> 2.1.3
>>>
>



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