diff options
| author | Stefan Binding | 2022-01-21 17:24:26 +0000 |
|---|---|---|
| committer | Mark Brown | 2022-02-01 16:09:04 +0000 |
| commit | 113962301d2d9a5c11381d9c25ddea7af71be2ff (patch) | |
| tree | 977b99fdc1e085a782658ada82a7b499915a169d | |
| parent | 92640f98a78c6a3ea1ca32143144241eceb129bd (diff) | |
spi: Add API to count spi acpi resources
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>
| -rw-r--r-- | drivers/spi/spi.c | 40 | ||||
| -rw-r--r-- | include/linux/spi/spi.h | 1 |
2 files changed, 41 insertions, 0 deletions
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index 06c0a308b38b..ec9f2ed579e3 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -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) { diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h index e5bbb9cbd3d7..394b4241d989 100644 --- a/include/linux/spi/spi.h +++ b/include/linux/spi/spi.h @@ -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 /* |