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SubjectRe: [PATCH v4 4/4] gpio: pl061: enable interrupts with DT style binding
On 02/09/2012 05:58 PM, Shawn Guo wrote:
> On Thu, Feb 09, 2012 at 04:03:10PM -0600, Rob Herring wrote:
>>
>> On 02/09/2012 02:04 PM, Shawn Guo wrote:
>>> On Fri, Feb 03, 2012 at 04:35:12PM -0600, Rob Herring wrote:
>>> ...
>>>> @@ -126,18 +127,16 @@ static void pl061_set_value(struct gpio_chip *gc, unsigned offset, int value)
>>>> static int pl061_to_irq(struct gpio_chip *gc, unsigned offset)
>>>> {
>>>> struct pl061_gpio *chip = container_of(gc, struct pl061_gpio, gc);
>>>> -
>>>> - if (chip->irq_base <= 0)
>>>> - return -EINVAL;
>>>> -
>>>> - return chip->irq_base + offset;
>>>> + if (!chip->irq_gc)
>>>> + return -ENXIO;
>>>> + return irq_find_mapping(chip->irq_gc->domain, offset);
>>>
>>> If I understand the driver correctly, it will add a linear domain for
>>> dt case. Do you have code somewhere creating the mapping before this
>>> irq_find_mapping gets called here? The reason I'm asking this is I
>>> have to call irq_create_mapping rather than irq_find_mapping here to
>>> get imx gpio driver working with linear domain, otherwise the
>>> irq_find_mapping call will fail.
>>>
>>
>> Right, the user has to call irq_of_parse_and_map (which calls
>> irq_create_mapping ultimately). Interrupts are allocated on demand. The
>> dts needs to declare the gpio controller as an interrupt-controller and
>> the node using the gpio line needs to set its interrupt parent and
>> interrupt connection
>>
> Yes, that's how dt users use irq. But since I'm trying to make the
> imx gpio irq_domain as linear for both non-dt and dt users. Calling
> irq_create_mapping here may make sense for me, since it will not
> require all these non-dt users change the way they use gpio irq.
>

I wouldn't try to use linear for non-DT at this point.

> Even for dt users, there may have some case that can not work in the
> way we expect.
>
> soc {
> #address-cells = <1>;
> #size-cells = <1>;
> compatible = "simple-bus";
> interrupt-parent = <&tzic>;
> ranges;
>
> esdhc@70008000 { /* ESDHC2 */
> compatible = "fsl,imx51-esdhc";
> reg = <0x70008000 0x4000>;
> interrupts = <2>;
> cd-gpios = <&gpio1 6 0>;
> wp-gpios = <&gpio1 5 0>;
> };
> };
>
> In above SD example, irq_of_parse_and_map will just work out the SD
> controller internal irq to tzic. How can we work out the card-detection
> irq to gpio controller in the same way?
>

That's the limitation in the interrupt binding. Normally, an interrupt
nexus is used for this.

Rob


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