diff mbox series

[v6,1/4] bus: mhi: core: Add helper API to return number of free TREs

Message ID 1600286167-4432-2-git-send-email-hemantk@codeaurora.org
State Superseded
Headers show
Series user space client interface driver | expand

Commit Message

Hemant Kumar Sept. 16, 2020, 7:56 p.m. UTC
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(+)

Comments

Manivannan Sadhasivam Sept. 27, 2020, 3:12 a.m. UTC | #1
On Wed, Sep 16, 2020 at 12:56:04PM -0700, Hemant Kumar wrote:
> 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);


Hmm, so this is essentially a wrapper for get_nr_avail_ring_elements().
Why can't you call this API directly?

> +}

> +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


mhi_get_nr_free_descriptors?

> + * 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);


Align enum with start of "("

Thanks,
Mani

> +

> +/**

>   * 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

>
diff mbox series

Patch

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