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 --- drivers/spi/spi.c | 40 ++++++++++++++++++++++++++++++++++++++++ include/linux/spi/spi.h | 1 + 2 files changed, 41 insertions(+)
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
/*