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-rw-r--r--drivers/dma/dmaengine.c10
-rw-r--r--include/linux/dmaengine.h4
2 files changed, 14 insertions, 0 deletions
diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c
index 8177f78faeda..a53e71d2bbd4 100644
--- a/drivers/dma/dmaengine.c
+++ b/drivers/dma/dmaengine.c
@@ -601,6 +601,16 @@ int dma_get_slave_caps(struct dma_chan *chan, struct dma_slave_caps *caps)
caps->cmd_resume = !!device->device_resume;
caps->cmd_terminate = !!device->device_terminate_all;
+ /*
+ * DMA engine device might be configured with non-uniformly
+ * distributed slave capabilities per device channels. In this
+ * case the corresponding driver may provide the device_caps
+ * callback to override the generic capabilities with
+ * channel-specific ones.
+ */
+ if (device->device_caps)
+ device->device_caps(chan, caps);
+
return 0;
}
EXPORT_SYMBOL_GPL(dma_get_slave_caps);
diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h
index 4cbe09e66db2..d718671bfd25 100644
--- a/include/linux/dmaengine.h
+++ b/include/linux/dmaengine.h
@@ -801,6 +801,8 @@ struct dma_filter {
* be called after period_len bytes have been transferred.
* @device_prep_interleaved_dma: Transfer expression in a generic way.
* @device_prep_dma_imm_data: DMA's 8 byte immediate data to the dst address
+ * @device_caps: May be used to override the generic DMA slave capabilities
+ * with per-channel specific ones
* @device_config: Pushes a new configuration to a channel, return 0 or an error
* code
* @device_pause: Pauses any transfer happening on a channel. Returns
@@ -901,6 +903,8 @@ struct dma_device {
struct dma_chan *chan, dma_addr_t dst, u64 data,
unsigned long flags);
+ void (*device_caps)(struct dma_chan *chan,
+ struct dma_slave_caps *caps);
int (*device_config)(struct dma_chan *chan,
struct dma_slave_config *config);
int (*device_pause)(struct dma_chan *chan);