linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
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: [RESEND v15 1/4] bus: mhi: core: Add helper API to return number of free TREs
Date: Thu,  3 Dec 2020 18:41:48 -0800	[thread overview]
Message-ID: <1607049711-31776-2-git-send-email-hemantk@codeaurora.org> (raw)
In-Reply-To: <1607049711-31776-1-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


  reply	other threads:[~2020-12-04  2:42 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-12-04  2:41 [RESEND v15 0/4] userspace MHI client interface driver Hemant Kumar
2020-12-04  2:41 ` Hemant Kumar [this message]
2020-12-04  2:41 ` [RESEND v15 2/4] bus: mhi: core: Move MHI_MAX_MTU to external header file Hemant Kumar
2020-12-04  2:41 ` [RESEND v15 3/4] docs: Add documentation for userspace client interface Hemant Kumar
2020-12-04  2:41 ` [RESEND v15 4/4] bus: mhi: Add userspace client interface driver Hemant Kumar

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1607049711-31776-2-git-send-email-hemantk@codeaurora.org \
    --to=hemantk@codeaurora.org \
    --cc=bbhatt@codeaurora.org \
    --cc=gregkh@linuxfoundation.org \
    --cc=jhugo@codeaurora.org \
    --cc=linux-arm-msm@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=loic.poulain@linaro.org \
    --cc=manivannan.sadhasivam@linaro.org \
    --cc=netdev@vger.kernel.org \
    --subject='Re: [RESEND v15 1/4] bus: mhi: core: Add helper API to return number of free TREs' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).