acpi-dma: convert to return error code when asked for channel

Currently acpi_dma_request_slave_chan_by_index() and
acpi_dma_request_slave_chan_by_name() return only requested channel or NULL.
This patch converts them to return appropriate error code instead of NULL in
case of unsuccessfull request.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

1 files changed, 3 insertions, 2 deletions

diff --git a/include/linux/acpi_dma.h b/include/linux/acpi_dma.h
index fb0298082916..329436d38e66 100644
--- a/include/linux/acpi_dma.h
+++ b/include/linux/acpi_dma.h
@@ -16,6 +16,7 @@
 
 #include <linux/list.h>
 #include <linux/device.h>
+#include <linux/err.h>
 #include <linux/dmaengine.h>
 
 /**
@@ -103,12 +104,12 @@ static inline void devm_acpi_dma_controller_free(struct device *dev)
 static inline struct dma_chan *acpi_dma_request_slave_chan_by_index(
                 struct device *dev, size_t index)
 {
-        return NULL;
+        return ERR_PTR(-ENODEV);
 }
 static inline struct dma_chan *acpi_dma_request_slave_chan_by_name(
                 struct device *dev, const char *name)
 {
-        return NULL;
+        return ERR_PTR(-ENODEV);
 }
 
 #define acpi_dma_simple_xlate   NULL