@@ -357,11 +357,14 @@ struct dma_chan {
* @chan: driver channel device
* @device: sysfs device
* @dev_id: parent dma_device dev_id
+ * @chan_dma_dev: The channel is using custom/different dma-mapping
+ * compared to the parent dma_device
*/
struct dma_chan_dev {
struct dma_chan *chan;
struct device device;
int dev_id;
+ bool chan_dma_dev;
};
/**
@@ -1613,4 +1616,13 @@ dmaengine_get_direction_text(enum dma_transfer_direction dir)
return "invalid";
}
}
+
+static inline struct device *dmaengine_get_dma_device(struct dma_chan *chan)
+{
+ if (chan->dev->chan_dma_dev)
+ return &chan->dev->device;
+
+ return chan->device->dev;
+}
+
#endif /* DMAENGINE_H */
If the DMA device supports per channel coherency configuration (a channel can be configured to have coherent or not coherent view) then a single device (the DMA controller's device) can not be used for dma_api for all channels as channels can have different coherency. Introduce custom_dma_mapping flag for the dma_chan and a new helper to get the device pointer to be used for dma_api for the given channel. Client drivers should be updated to be able to support per channel coherency by: - dma_map_single(chan->device->dev, ptr, size, DMA_TO_DEVICE); + struct device *dma_dev = dmaengine_get_dma_device(chan); + + dma_map_single(dma_dev, ptr, size, DMA_TO_DEVICE); Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com> --- include/linux/dmaengine.h | 12 ++++++++++++ 1 file changed, 12 insertions(+)