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spi: Add API to count spi acpi resources

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Some ACPI nodes may have more than one Spi Resource.
To be able to handle these case, its necessary to have
a way of counting these resources.

Signed-off-by: Stefan Binding <sbinding@opensource.cirrus.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20220121172431.6876-5-sbinding@opensource.cirrus.com
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Stefan Binding 2022-01-21 17:24:26 +00:00 committed by Mark Brown
parent 87e59b36e5
commit e612af7ace
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2 changed files with 41 additions and 0 deletions
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40
drivers/spi/spi.c
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@ -2324,6 +2324,46 @@ struct acpi_spi_lookup {
int index;
};
static int acpi_spi_count(struct acpi_resource *ares, void *data)
{
struct acpi_resource_spi_serialbus *sb;
int *count = data;
if (ares->type != ACPI_RESOURCE_TYPE_SERIAL_BUS)
return 1;
sb = &ares->data.spi_serial_bus;
if (sb->type != ACPI_RESOURCE_SERIAL_TYPE_SPI)
return 1;
*count = *count + 1;
return 1;
}
/**
* acpi_spi_count_resources - Count the number of SpiSerialBus resources
* @adev: ACPI device
*
* Returns the number of SpiSerialBus resources in the ACPI-device's
* resource-list; or a negative error code.
*/
int acpi_spi_count_resources(struct acpi_device *adev)
{
LIST_HEAD(r);
int count = 0;
int ret;
ret = acpi_dev_get_resources(adev, &r, acpi_spi_count, &count);
if (ret < 0)
return ret;
acpi_dev_free_resource_list(&r);
return count;
}
EXPORT_SYMBOL_GPL(acpi_spi_count_resources);
static void acpi_spi_parse_apple_properties(struct acpi_device *dev,
struct acpi_spi_lookup *lookup)
{

1
include/linux/spi/spi.h
View File

@ -764,6 +764,7 @@ extern void spi_unregister_controller(struct spi_controller *ctlr);
extern struct spi_device *acpi_spi_device_alloc(struct spi_controller *ctlr,
struct acpi_device *adev,
int index);
int acpi_spi_count_resources(struct acpi_device *adev);
#endif
/*