Hi Jonathan,
Jonathan Cameron wrote on 2010-03-08:
> Hi Michael,
>
> I'm wondering about this one. Are you sure all platforms have the
> correct gpio setup when doing the request_irq?
> (those that need it obviously, basically the question is whether all
> platforms default to having gpio's as inputs).
>
> If the do there is certainly a lot of redundant code about based on a
> quick bit of grepping. (loads of it in arm/mach-pxa for starters). In
> that particular case all gpio's are configured as inputs, but I'm not
> sure other platforms are so well behaved.
>
>
> Unless I'm completely wrong that means we have run into a rather
> general issue.
By no means - you have to first configure a GPIO_IRQ as GPIO-Input and then as IRQ.
irq_type takes care of it. In your case you gave the IRQF_TRIGGER_RISING flag with request_irq().
In case such a IRQF_TRIGGER_XXX flag is present the common IRQ infrastructure will call the associated irq_chips irq_type() function.
This function is supposed to take care for all of it.(GPIO input, setting the level, edge and polarity)
As an alternative you can request_irq() without the IRQF_TRIGGER_XXX flags and use set_irq_type() anytime later, or even in advance.
>
> Also, if this is fine, the right fix is probably to have the interrupt
> as the platform data parameter rather than the gpio. It makes the
> code more general and moves a lot of these direction issues etc into
> the board specific areas rather than here.
Of course this is an option.
Regards,
Michael
>
> Also, CC Greg KH on any patches like this which are fixes.
>
> Jonathan
>
>> Remove redundant gpio_request. The GPIO used as trigger IRQ, is also
>> requested as gpio, but actually never read. On some platforms a GPIO
>> requested as IRQ can't be requested as GPIO as well.
>>
>> From: Michael Hennerich <Michael.Hennerich@xxxxxxxxxx>
>>
>> Index: drivers/staging/iio/trigger/iio-trig-gpio.c
>> ===================================================================
>> --- drivers/staging/iio/trigger/iio-trig-gpio.c (revision 8368)
>> +++ drivers/staging/iio/trigger/iio-trig-gpio.c (working copy)
>> @@ -94,18 +94,11 @@
>> IIO_TRIGGER_NAME_LENGTH,
>> "gpiotrig%d",
>> pdata[i]);
>> - ret = gpio_request(trig_info->gpio, trig->name);
>> - if (ret)
>> - goto error_free_name;
>>
>> - ret = gpio_direction_input(trig_info->gpio);
>> - if (ret)
>> - goto error_release_gpio;
>> -
>> irq = gpio_to_irq(trig_info->gpio);
>> if (irq < 0) {
>> ret = irq;
>> - goto error_release_gpio;
>> + goto error_free_name;
>> }
>>
>> ret = request_irq(irq, iio_gpio_trigger_poll, @@
>> -113,7 +106,7 @@
>> trig->name,
>> trig);
>> if (ret)
>> - goto error_release_gpio;
>> + goto error_free_name;
>>
>> ret = iio_trigger_register(trig);
>> if (ret)
>> @@ -127,8 +120,6 @@
>> /* First clean up the partly allocated trigger */
>> error_release_irq:
>> free_irq(irq, trig);
>> -error_release_gpio:
>> - gpio_free(trig_info->gpio);
>> error_free_name:
>> kfree(trig->name);
>> error_free_trig_info:
>> @@ -143,7 +134,6 @@
>> alloc_list) {
>> trig_info = trig->private_data;
>> free_irq(gpio_to_irq(trig_info->gpio), trig); -
>> gpio_free(trig_info->gpio); kfree(trig->name);
>> kfree(trig_info); iio_trigger_unregister(trig); @@
>> -166,7 +156,6 @@ trig_info = trig->private_data;
>> iio_trigger_unregister(trig);
>> free_irq(gpio_to_irq(trig_info->gpio), trig); -
>> gpio_free(trig_info->gpio); kfree(trig->name);
>> kfree(trig_info); iio_put_trigger(trig);
>>
>>
>> ------------------------------------------------------------------
>> ********* Analog Devices GmbH Open Platform Solutions
>> ** *****
>> ** ** Wilhelm-Wagenfeld-Strasse 6
>> ** ***** D-80807 Munich
>> ********* Germany
>> Registergericht München HRB 40368, Geschäftsführer: Thomas Wessel,
>> William A. Martin, Margaret K. Seif
>>
Greetings,
Michael
Analog Devices GmbH Wilhelm-Wagenfeld-Str. 6 80807 Muenchen
Sitz der Gesellschaft Muenchen, Registergericht Muenchen HRB 4036 Geschaeftsfuehrer Thomas Wessel, William A. Martin, Margaret Seif
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