Re: [PATCH] IIO: Adds ACPI support for ST gyroscopes

From: Robert Dolca
Date: Wed Mar 25 2015 - 09:42:46 EST


On Wed, Mar 25, 2015 at 3:21 PM, Mika Westerberg
<mika.westerberg@xxxxxxxxxxxxxxx> wrote:
> On Wed, Mar 25, 2015 at 02:25:05PM +0200, Mika Westerberg wrote:
>> I think we can do the same for ACPI GpioInts so that we introduce
>> acpi_gpio_irq_get() that translates from GpioInt to Linux IRQ
>> numberspace. Then we can do something like below in I2C core:
>>
>> if (client->irq <= 0) {
>> int irq = -ENOENT;
>>
>> if (dev->of_node)
>> irq = of_irq_get(dev->of_node, 0);
>> else if (ACPI_COMPANION(dev))
>> irq = acpi_gpio_irq_get(ACPI_COMPANION(dev), 0);
>>
>> if (irq == -EPROBE_DEFER)
>> return irq;
>> if (irq < 0)
>> irq = 0;
>>
>> client->irq = irq;
>> }
>>
>> Now it has the drawback that the first GpioInt will not be available to
>> the driver anymore (as a GPIO since it is locked) but if DT already does
>> the same we should be fine.
>
> Below patch should take care of this.
>
> Robert, can you try it out?
>
> If people think this is the right way to go forward, I'll make formal
> patches and submit them for review.
>
> diff --git a/drivers/gpio/gpiolib-acpi.c b/drivers/gpio/gpiolib-acpi.c
> index c0929d938ced..ed7c40c7b4ab 100644
> --- a/drivers/gpio/gpiolib-acpi.c
> +++ b/drivers/gpio/gpiolib-acpi.c
> @@ -510,6 +510,36 @@ struct gpio_desc *acpi_get_gpiod_by_index(struct acpi_device *adev,
> return lookup.desc ? lookup.desc : ERR_PTR(-ENOENT);
> }
>
> +/**
> + * acpi_dev_gpio_irq_get() - Find GpioInt and translate it to Linux IRQ number
> + * @adev: pointer to a ACPI device to get IRQ from
> + * @index: index of GpioInt resource (starting from %0)
> + *
> + * If the device has one or more GpioInt resources, this function can be
> + * used to translate from the GPIO offset in the resource to the Linux IRQ
> + * number.
> + *
> + * Return: Linux IRQ number (>%0) on success, negative errno on failure.
> + */
> +int acpi_dev_gpio_irq_get(struct acpi_device *adev, int index)
> +{
> + struct gpio_desc *desc;
> + int i = 0;
> +
> + do {
> + struct acpi_gpio_info info;
> +
> + desc = acpi_get_gpiod_by_index(adev, NULL, i, &info);
> + if (!IS_ERR(desc)) {
> + if (info.gpioint && i++ == index)
> + return gpiod_to_irq(desc);
> + }
> + } while (!IS_ERR(desc));
> +
> + return -ENOENT;
> +}
> +EXPORT_SYMBOL_GPL(acpi_dev_gpio_irq_get);
> +
> static acpi_status
> acpi_gpio_adr_space_handler(u32 function, acpi_physical_address address,
> u32 bits, u64 *value, void *handler_context,
> diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
> index edf274cabe81..c12a3f24ada4 100644
> --- a/drivers/i2c/i2c-core.c
> +++ b/drivers/i2c/i2c-core.c
> @@ -629,8 +629,13 @@ static int i2c_device_probe(struct device *dev)
> if (!client)
> return 0;
>
> - if (!client->irq && dev->of_node) {
> - int irq = of_irq_get(dev->of_node, 0);
> + if (client->irq <= 0) {
> + int irq = -ENOENT;
> +
> + if (dev->of_node)
> + irq = of_irq_get(dev->of_node, 0);
> + else if (ACPI_COMPANION(dev))
> + irq = acpi_dev_gpio_irq_get(ACPI_COMPANION(dev), 0);
>
> if (irq == -EPROBE_DEFER)
> return irq;
> diff --git a/include/linux/acpi.h b/include/linux/acpi.h
> index 24c7aa8b1d20..826e214ab7d5 100644
> --- a/include/linux/acpi.h
> +++ b/include/linux/acpi.h
> @@ -704,6 +704,8 @@ static inline void acpi_dev_remove_driver_gpios(struct acpi_device *adev)
> if (adev)
> adev->driver_gpios = NULL;
> }
> +
> +int acpi_dev_gpio_irq_get(struct acpi_device *adev, int index);
> #else
> static inline int acpi_dev_add_driver_gpios(struct acpi_device *adev,
> const struct acpi_gpio_mapping *gpios)
> @@ -711,6 +713,11 @@ static inline int acpi_dev_add_driver_gpios(struct acpi_device *adev,
> return -ENXIO;
> }
> static inline void acpi_dev_remove_driver_gpios(struct acpi_device *adev) {}
> +
> +static inline int acpi_dev_gpio_irq_get(struct acpi_device *adev, int index)
> +{
> + return -ENXIO;
> +}
> #endif
>
> /* Device properties */

Hi Mika,

I will try it and come back with more info.

Robert
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