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@xxxxxxxxxxxxxxxxxxxxx>
---
drivers/spi/spi.c | 40 ++++++++++++++++++++++++++++++++++++++++
include/linux/spi/spi.h | 6 ++++++
2 files changed, 46 insertions(+)
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index 898cc9931490..8c0c2e26609a 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -2325,6 +2325,46 @@ struct acpi_spi_lookup {
int irq_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 1a34fd0f6ca2..25a82729f8da 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 irq_index);
+int acpi_spi_count_resources(struct acpi_device *adev);
#else
static inline struct spi_device *acpi_spi_device_alloc(struct spi_controller *ctlr,
struct acpi_device *adev,
@@ -771,6 +772,11 @@ static inline struct spi_device *acpi_spi_device_alloc(struct spi_controller *ct
{
return ERR_PTR(-EOPNOTSUPP);
}
+
+int acpi_spi_count_resources(struct acpi_device *adev)
+{
+ return -EOPNOTSUPP;
+}
#endif
/*
--
2.25.1
