diff options
| author | Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> | 2022-04-05 19:27:50 +0530 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-04-26 13:17:41 +0200 |
| commit | 530125889977365cb6db32d7d0bd84c9f54c8aab (patch) | |
| tree | 978f98404e39b0dba3131f960344ca52aa01a7e9 /include/linux/mhi_ep.h | |
| parent | e827569062a804c67b51930ce83a4cb886113cb7 (diff) | |
bus: mhi: ep: Add support for reading from the host
Data transfer between host and the ep device happens over the transfer
ring associated with each bi-directional channel pair. Host defines the
transfer ring by allocating memory for it. The read and write pointer
addresses of the transfer ring are stored in the channel context.
Once host places the elements in the transfer ring, it increments the
write pointer and rings the channel doorbell. Device will receive the
doorbell interrupt and will process the transfer ring elements.
This commit adds support for reading the transfer ring elements from
the transfer ring till write pointer, incrementing the read pointer and
finally sending the completion event to the host through corresponding
event ring.
Reviewed-by: Alex Elder <elder@linaro.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/20220405135754.6622-15-manivannan.sadhasivam@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'include/linux/mhi_ep.h')
| -rw-r--r-- | include/linux/mhi_ep.h | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/include/linux/mhi_ep.h b/include/linux/mhi_ep.h index 8c6406d9c51f..fc7d197413eb 100644 --- a/include/linux/mhi_ep.h +++ b/include/linux/mhi_ep.h @@ -254,4 +254,13 @@ int mhi_ep_power_up(struct mhi_ep_cntrl *mhi_cntrl); */ void mhi_ep_power_down(struct mhi_ep_cntrl *mhi_cntrl); +/** + * mhi_ep_queue_is_empty - Determine whether the transfer queue is empty + * @mhi_dev: Device associated with the channels + * @dir: DMA direction for the channel + * + * Return: true if the queue is empty, false otherwise. + */ +bool mhi_ep_queue_is_empty(struct mhi_ep_device *mhi_dev, enum dma_data_direction dir); + #endif |