From: Hemant Kumar <hemantk@codeaurora.org>
To: manivannan.sadhasivam@linaro.org, gregkh@linuxfoundation.org
Cc: linux-arm-msm@vger.kernel.org, hemantk@codeaurora.org,
jhugo@codeaurora.org, linux-kernel@vger.kernel.org
Subject: [PATCH v4 1/4] bus: mhi: core: Add helper API to return number of free TREs
Date: Tue, 28 Jul 2020 20:46:32 -0700 [thread overview]
Message-ID: <1595994395-20143-2-git-send-email-hemantk@codeaurora.org> (raw)
In-Reply-To: <1595994395-20143-1-git-send-email-hemantk@codeaurora.org>
Introduce mhi_get_no_free_descriptors() 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>
---
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 2cff5dd..0599e7d 100644
--- a/drivers/bus/mhi/core/main.c
+++ b/drivers/bus/mhi/core/main.c
@@ -258,6 +258,18 @@ int mhi_destroy_device(struct device *dev, void *data)
return 0;
}
+int mhi_get_no_free_descriptors(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_no_free_descriptors);
+
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 a35d876..6565528 100644
--- a/include/linux/mhi.h
+++ b/include/linux/mhi.h
@@ -600,6 +600,15 @@ 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_no_free_descriptors - 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_no_free_descriptors(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:[~2020-07-29 3:47 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-29 3:46 [PATCH v4 0/4] user space client interface driver Hemant Kumar
2020-07-29 3:46 ` Hemant Kumar [this message]
2020-07-29 3:46 ` [PATCH v4 2/4] bus: mhi: core: Move MHI_MAX_MTU to external header file Hemant Kumar
2020-07-29 3:46 ` [PATCH v4 3/4] docs: Add documentation for userspace client interface Hemant Kumar
2020-07-29 3:46 ` [PATCH v4 4/4] bus: mhi: clients: Add userspace client interface driver Hemant Kumar
2020-07-29 6:17 ` Greg KH
2020-07-30 3:06 ` 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=1595994395-20143-2-git-send-email-hemantk@codeaurora.org \
--to=hemantk@codeaurora.org \
--cc=gregkh@linuxfoundation.org \
--cc=jhugo@codeaurora.org \
--cc=linux-arm-msm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=manivannan.sadhasivam@linaro.org \
/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
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
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).