From 87baa23e0236bc1c41ce744f524bf12dbe7fde66 Mon Sep 17 00:00:00 2001 From: Hemant Kumar Date: Mon, 11 Jan 2021 19:07:40 +0100 Subject: bus: mhi: core: Add helper API to return number of free TREs Introduce mhi_get_free_desc_count() API to return number of TREs available to queue buffer. MHI clients can use this API to know before hand if ring is full without calling queue API. Signed-off-by: Hemant Kumar Reviewed-by: Jeffrey Hugo Reviewed-by: Manivannan Sadhasivam Link: https://lore.kernel.org/r/1610388462-16322-1-git-send-email-loic.poulain@linaro.org Signed-off-by: Manivannan Sadhasivam --- include/linux/mhi.h | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'include/linux/mhi.h') diff --git a/include/linux/mhi.h b/include/linux/mhi.h index 562862ff819c..ece53a252217 100644 --- a/include/linux/mhi.h +++ b/include/linux/mhi.h @@ -598,6 +598,15 @@ void mhi_set_mhi_state(struct mhi_controller *mhi_cntrl, */ void mhi_notify(struct mhi_device *mhi_dev, enum mhi_callback cb_reason); +/** + * mhi_get_free_desc_count - Get transfer ring length + * Get # of TD available to queue buffers + * @mhi_dev: Device associated with the channels + * @dir: Direction of the channel + */ +int mhi_get_free_desc_count(struct mhi_device *mhi_dev, + enum dma_data_direction dir); + /** * mhi_prepare_for_power_up - Do pre-initialization before power up. * This is optional, call this before power up if -- cgit v1.2.3