From: Hemant Kumar <hemantk@codeaurora.org>
To: manivannan.sadhasivam@linaro.org, gregkh@linuxfoundation.org
Cc: linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org,
jhugo@codeaurora.org, bbhatt@codeaurora.org,
loic.poulain@linaro.org, netdev@vger.kernel.org,
Hemant Kumar <hemantk@codeaurora.org>
Subject: [PATCH v15 1/4] bus: mhi: core: Add helper API to return number of free TREs
Date: Thu, 3 Dec 2020 14:45:13 -0800 [thread overview]
Message-ID: <1607035516-3093-2-git-send-email-hemantk@codeaurora.org> (raw)
In-Reply-To: <1607035516-3093-1-git-send-email-hemantk@codeaurora.org>
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 <hemantk@codeaurora.org>
Reviewed-by: Jeffrey Hugo <jhugo@codeaurora.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
---
drivers/bus/mhi/core/main.c | 12 ++++++++++++
include/linux/mhi.h | 9 +++++++++
2 files changed, 21 insertions(+)
diff --git a/drivers/bus/mhi/core/main.c b/drivers/bus/mhi/core/main.c
index 702c31b..74a25e7 100644
--- a/drivers/bus/mhi/core/main.c
+++ b/drivers/bus/mhi/core/main.c
@@ -260,6 +260,18 @@ int mhi_destroy_device(struct device *dev, void *data)
return 0;
}
+int mhi_get_free_desc_count(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 get_nr_avail_ring_elements(mhi_cntrl, tre_ring);
+}
+EXPORT_SYMBOL_GPL(mhi_get_free_desc_count);
+
void mhi_notify(struct mhi_device *mhi_dev, enum mhi_callback cb_reason)
{
struct mhi_driver *mhi_drv;
diff --git a/include/linux/mhi.h b/include/linux/mhi.h
index aa9757e..e36d575 100644
--- a/include/linux/mhi.h
+++ b/include/linux/mhi.h
@@ -599,6 +599,15 @@ 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
* the controller does not want bus framework to
--
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project
next prev parent reply other threads:[~2020-12-03 22:46 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-03 22:45 [PATCH v15 0/4] userspace MHI client interface driver Hemant Kumar
2020-12-03 22:45 ` Hemant Kumar [this message]
2020-12-03 22:45 ` [PATCH v15 2/4] bus: mhi: core: Move MHI_MAX_MTU to external header file Hemant Kumar
2020-12-03 22:45 ` [PATCH v15 3/4] docs: Add documentation for userspace client interface Hemant Kumar
2020-12-03 22:45 ` [PATCH v15 4/4] bus: mhi: Add userspace client interface driver Hemant Kumar
2020-12-03 23:45 ` Jeffrey Hugo
2020-12-04 2:31 ` Hemant Kumar
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