Re: [PATCH 3/5] gpio/omap: Add DT support to GPIO driver

["Cousson, Benoit" <b-cousson@ti.com>]

On 2/22/2012 7:29 PM, Stephen Warren wrote:
> Rob Herring wrote at Wednesday, February 22, 2012 10:23 AM:
>> On 02/22/2012 08:31 AM, Cousson, Benoit wrote:
>>> On 2/22/2012 3:23 PM, Rob Herring wrote:
>>>> On 02/15/2012 10:04 AM, Benoit Cousson wrote:
>>>>> Adapt the GPIO driver to retrieve information from a DT file.
>>>>>
>>>>> Allocate the irq_base dynamically and rename bank->virtual_irq_start
>>>>> to bank->irq_base.
>>>>> Change irq_base type to int instead of u16 to match irq_alloc_descs
>>>>> output.
>>>>>
>>>>> Add documentation for GPIO properties specific to OMAP.
>>>>>
>>>>> Signed-off-by: Benoit Cousson<b-cousson@ti.com>
>>>>> Cc: Tarun Kanti DebBarma<tarun.kanti@ti.com>
>>>>
>>>> One comment below, but otherwise:
>>>>
>>>> Acked-by: Rob Herring<rob.herring@calxeda.com>
>>>>
>>>>> ---
>>>>>    .../devicetree/bindings/gpio/gpio-omap.txt         |   30 +++++
>>>>>    drivers/gpio/gpio-omap.c                           |  121
>>>>> ++++++++++++++++++--
>>>>>    2 files changed, 142 insertions(+), 9 deletions(-)
>>>>>    create mode 100644
>>>>> Documentation/devicetree/bindings/gpio/gpio-omap.txt
>>>>>
>>>>> diff --git a/Documentation/devicetree/bindings/gpio/gpio-omap.txt
>>>>> b/Documentation/devicetree/bindings/gpio/gpio-omap.txt
>>>>> new file mode 100644
>>>>> index 0000000..c1b3100
>>>>> --- /dev/null
>>>>> +++ b/Documentation/devicetree/bindings/gpio/gpio-omap.txt
>>>>> @@ -0,0 +1,30 @@
>>>>> +OMAP GPIO controller bindings
>>>>> +
>>>>> +Required properties:
>>>>> +- compatible:
>>>>> +  - "ti,omap2-gpio" for OMAP2 controllers
>>>>> +  - "ti,omap3-gpio" for OMAP3 controllers
>>>>> +  - "ti,omap4-gpio" for OMAP4 controllers
>>>>> +- #gpio-cells : Should be two.
>>>>> +  - first cell is the pin number
>>>>> +  - second cell is used to specify optional parameters (unused)
>>>>> +- gpio-controller : Marks the device node as a GPIO controller.
>>>>> +- #interrupt-cells : Should be one
>>>>
>>>> There's no level/edge settings for gpios?
>>>
>>> That's a good question, because I was wondering as well :-)
>>>
>>> I did no see how it was done in other GPIO implementation.
>>
>> There's not really a good example that I've found. Many gpio nodes don't
>> even have "interrupt-controller" set.
>>
>> So if you have an irq_set_type function for gpio's, then you should have
>> 2 cells.

After checking the OMAP gpio code, I do have a gpio_irq_type and the 
GPIO do support the 4 types. I'm not sure yet about the combinations.

> Tegra's GPIO IRQ binding (gpio_nvidia.txt in linux-next at least) says:
>
> - #interrupt-cells : Should be 2.
>    The first cell is the GPIO number.
>    The second cell is used to specify flags:
>      bits[3:0] trigger type and level flags:
>        1 = low-to-high edge triggered.
>        2 = high-to-low edge triggered.
>        4 = active high level-sensitive.
>        8 = active low level-sensitive.
>        Valid combinations are 1, 2, 3, 4, 8.

Indeed, so I'll just copy / paste Tegra's binding...

Thanks,
Benoit