[PATCH v2 1/6] spi: Export acpi_spi_find_controller_by_adev to be used externally

[Stefan Binding <sbinding@opensource.cirrus.com>]

This will be used by bus-multi-instantiate to support spi.

Signed-off-by: Stefan Binding <sbinding@opensource.cirrus.com>
---
 drivers/spi/spi.c       |  3 ++-
 include/linux/spi/spi.h | 10 ++++++++++
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index 8726309b3eaf..9495f776e53c 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -4200,7 +4200,7 @@ static int spi_acpi_controller_match(struct device *dev, const void *data)
 	return ACPI_COMPANION(dev->parent) == data;
 }
 
-static struct spi_controller *acpi_spi_find_controller_by_adev(struct acpi_device *adev)
+struct spi_controller *acpi_spi_find_controller_by_adev(struct acpi_device *adev)
 {
 	struct device *dev;
 
@@ -4214,6 +4214,7 @@ static struct spi_controller *acpi_spi_find_controller_by_adev(struct acpi_devic
 
 	return container_of(dev, struct spi_controller, dev);
 }
+EXPORT_SYMBOL_GPL(acpi_spi_find_controller_by_adev);
 
 static struct spi_device *acpi_spi_find_device_by_adev(struct acpi_device *adev)
 {
diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h
index eb7ac8a1e03c..8c2978853573 100644
--- a/include/linux/spi/spi.h
+++ b/include/linux/spi/spi.h
@@ -17,6 +17,7 @@
 #include <linux/ptp_clock_kernel.h>
 
 #include <uapi/linux/spi/spi.h>
+#include <linux/acpi.h>
 
 struct dma_chan;
 struct software_node;
@@ -759,6 +760,15 @@ extern int devm_spi_register_controller(struct device *dev,
 					struct spi_controller *ctlr);
 extern void spi_unregister_controller(struct spi_controller *ctlr);
 
+#if IS_ENABLED(CONFIG_ACPI)
+extern struct spi_controller *acpi_spi_find_controller_by_adev(struct acpi_device *adev);
+#else
+static inline struct spi_controller *acpi_spi_find_controller_by_adev(struct acpi_device *adev)
+{
+	return ERR_PTR(-EOPNOTSUPP);
+}
+#endif
+
 /*
  * SPI resource management while processing a SPI message
  */
-- 
2.25.1