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| author | Stefan Binding <sbinding@opensource.cirrus.com> | 2022-01-21 20:24:26 +0300 |
|---|---|---|
| committer | Mark Brown <broonie@kernel.org> | 2022-02-01 20:38:48 +0300 |
| commit | e612af7acef2459f1afd885f4107748995a05963 (patch) | |
| tree | f7383247760b2b99705a15725a9cf590d9fd31d2 /drivers/spi | |
| parent | 87e59b36e5e26122efd55d77adb9fac827987db0 (diff) | |
| download | linux-e612af7acef2459f1afd885f4107748995a05963.tar.xz | |
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>
Diffstat (limited to 'drivers/spi')
| -rw-r--r-- | drivers/spi/spi.c | 40 |
1 files changed, 40 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) { |