Re: [PATCH v4 2/4] gpiolib: add gpiod_get_array and gpiod_put_array functions

[Mika Westerberg <mika.westerberg@linux.intel.com>]

On Tue, Feb 10, 2015 at 02:40:52PM +0100, Rojhalat Ibrahim wrote:
> +#ifdef CONFIG_ACPI
> +
> +static unsigned int acpi_gpio_package_count(const union acpi_object *obj)
> +{
> +	const union acpi_object *element = obj->package.elements;
> +	const union acpi_object *end = element + obj->package.count;
> +	unsigned int count = 0;
> +
> +	while (element < end) {
> +		if (element->type == ACPI_TYPE_LOCAL_REFERENCE)
> +			count++;
> +
> +		element++;
> +	}
> +	return count;
> +}
> +
> +static int acpi_find_gpio_count(struct acpi_resource *ares, void *data)
> +{
> +	unsigned int *count = data;
> +
> +	if (ares->type == ACPI_RESOURCE_TYPE_GPIO)
> +		*count += ares->data.gpio.pin_table_length;
> +
> +	return 1;
> +}
> +
> +static int acpi_gpio_count(struct device *dev, const char *con_id)
> +{
> +	struct acpi_device *adev = ACPI_COMPANION(dev);
> +	const union acpi_object *obj;
> +	const struct acpi_gpio_mapping *gm;
> +	int count = -ENOENT;
> +	int ret;
> +	char propname[32];
> +	unsigned int i;
> +
> +	/* Try first from _DSD */
> +	for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
> +		if (con_id && strcmp(con_id, "gpios"))
> +			snprintf(propname, sizeof(propname), "%s-%s",
> +				 con_id, gpio_suffixes[i]);
> +		else
> +			snprintf(propname, sizeof(propname), "%s",
> +				 gpio_suffixes[i]);
> +
> +		ret = acpi_dev_get_property(adev, propname, ACPI_TYPE_ANY,
> +					    &obj);
> +		if (ret == 0) {
> +			if (obj->type == ACPI_TYPE_LOCAL_REFERENCE)
> +				count = 1;
> +			else if (obj->type == ACPI_TYPE_PACKAGE)
> +				count = acpi_gpio_package_count(obj);
> +		} else if (adev->driver_gpios) {
> +			for (gm = adev->driver_gpios; gm->name; gm++)
> +				if (strcmp(propname, gm->name) == 0) {
> +					count = gm->size;
> +					break;
> +				}
> +		}
> +		if (count >= 0)
> +			break;
> +	}
> +
> +	/* Then from plain _CRS GPIOs */
> +	if (count < 0) {
> +		struct list_head resource_list;
> +		unsigned int crs_count = 0;
> +
> +		INIT_LIST_HEAD(&resource_list);
> +		acpi_dev_get_resources(adev, &resource_list,
> +				       acpi_find_gpio_count, &crs_count);
> +		acpi_dev_free_resource_list(&resource_list);
> +		if (crs_count > 0)
> +			count = crs_count;
> +	}
> +	return count;
> +}
> +
> +#else
> +
> +static int acpi_gpio_count(struct device *dev, const char *con_id)
> +{
> +	return -ENODEV;
> +}
> +
> +#endif

It just occured to me that it would be better to put this code to
gpiolib-acpi.c and declare acpi_gpio_count() in drivers/gpio/gpiolib.h.

That said, I tested this code on Lenovo Thinkpad10 by converting
drivers/input/misc/soc_button_array.c to fetch its GPIOs using this new
API -- it works just fine (and looks better).

Once you have done the above change you can add for the ACPI parts,

Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>