bus: mhi: Add mhi_queue_is_full function

This function can be used by client driver to determine whether it's
possible to queue new elements in a channel ring.

Signed-off-by: Loic Poulain <loic.poulain@linaro.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/1604424234-24446-1-git-send-email-loic.poulain@linaro.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/bus/mhi/core/main.c b/drivers/bus/mhi/core/main.c
index 2cff5dd..ba9e721 100644 (file)
--- a/drivers/bus/mhi/core/main.c
+++ b/drivers/bus/mhi/core/main.c
@@ -1165,6 +1165,17 @@ int mhi_queue_buf(struct mhi_device *mhi_dev, enum dma_data_direction dir,
 }
 EXPORT_SYMBOL_GPL(mhi_queue_buf);
 
+bool mhi_queue_is_full(struct mhi_device *mhi_dev, enum dma_data_direction dir)
+{
+       struct mhi_controller *mhi_cntrl = mhi_dev->mhi_cntrl;
+       struct mhi_chan *mhi_chan = (dir == DMA_TO_DEVICE) ?
+                                       mhi_dev->ul_chan : mhi_dev->dl_chan;
+       struct mhi_ring *tre_ring = &mhi_chan->tre_ring;
+
+       return mhi_is_ring_full(mhi_cntrl, tre_ring);
+}
+EXPORT_SYMBOL_GPL(mhi_queue_is_full);
+
 int mhi_send_cmd(struct mhi_controller *mhi_cntrl,
                 struct mhi_chan *mhi_chan,
                 enum mhi_cmd_type cmd)

diff --git a/include/linux/mhi.h b/include/linux/mhi.h
index d4841e5..b9bb7df 100644 (file)
--- a/include/linux/mhi.h
+++ b/include/linux/mhi.h
@@ -737,4 +737,11 @@ int mhi_queue_buf(struct mhi_device *mhi_dev, enum dma_data_direction dir,
 int mhi_queue_skb(struct mhi_device *mhi_dev, enum dma_data_direction dir,
                  struct sk_buff *skb, size_t len, enum mhi_flags mflags);
 
+/**
+ * mhi_queue_is_full - Determine whether queueing new elements is possible
+ * @mhi_dev: Device associated with the channels
+ * @dir: DMA direction for the channel
+ */
+bool mhi_queue_is_full(struct mhi_device *mhi_dev, enum dma_data_direction dir);
+
 #endif /* _MHI_H_ */