[Sound-open-firmware] [RFC PATCH 2/6] dma: ops: introduce channel_status() op to retrieve number of channels in use

[Keyon Jie]

On 2018年06月05日 12:23, Ranjani Sridharan wrote:
> This patch adds a new dma op for retreiving the number of channels
> in use in a given DMAC. This will be useful in providing basic
> and primitive QoS while allocating DMAC for various users.
> 
> Signed-off-by: Ranjani Sridharan <ranjani.sridharan at linux.intel.com>
> ---
>   src/drivers/dw-dma.c  | 19 +++++++++++++++++++
>   src/drivers/hda-dma.c | 20 ++++++++++++++++++++
>   src/include/sof/dma.h |  7 +++++++
>   3 files changed, 46 insertions(+)
> 
> diff --git a/src/drivers/dw-dma.c b/src/drivers/dw-dma.c
> index c064330..0ed742f 100644
> --- a/src/drivers/dw-dma.c
> +++ b/src/drivers/dw-dma.c
> @@ -289,6 +289,24 @@ static inline void dw_update_bits(struct dma *dma, uint32_t reg, uint32_t mask,
>   	io_reg_update_bits(dma_base(dma) + reg, mask, value);
>   }
>   
> +/* get the number of DMA channels in use */
> +static int dw_dma_channel_status(struct dma *dma)
> +{
> +	struct dma_pdata *p = dma_get_drvdata(dma);
> +	int i, count = 0;
> +
> +	trace_dma("Dct");
> +
> +	for (i = 0; i < DW_MAX_CHAN; i++) {
> +
> +		/* find channels in use */
> +		if (p->chan[i].status != COMP_STATE_INIT)
> +			count++;
> +	}
> +
> +	return count;
> +}
> +
>   /* allocate next free DMA channel */
>   static int dw_dma_channel_get(struct dma *dma, int req_chan)
>   {
> @@ -1177,6 +1195,7 @@ static int dw_dma_probe(struct dma *dma)
>   const struct dma_ops dw_dma_ops = {
>   	.channel_get	= dw_dma_channel_get,
>   	.channel_put	= dw_dma_channel_put,
> +	.channel_status = dw_dma_channel_status,
>   	.start		= dw_dma_start,
>   	.stop		= dw_dma_stop,
>   	.pause		= dw_dma_pause,
> diff --git a/src/drivers/hda-dma.c b/src/drivers/hda-dma.c
> index 97ea0ef..0e88a35 100644
> --- a/src/drivers/hda-dma.c
> +++ b/src/drivers/hda-dma.c
> @@ -131,6 +131,24 @@ static int hda_dma_copy(struct dma *dma, int channel, int bytes)
>   	return 0;
>   }
>   
> +/* get the number of DMA channels in use */
> +static int hda_dma_channel_status(struct dma *dma)
> +{
> +	struct dma_pdata *p = dma_get_drvdata(dma);
> +	int i, count = 0;
> +
> +	trace_host("Dct");
> +
> +	for (i = 0; i < HDA_DMA_MAX_CHANS; i++) {
> +
> +		/* find channels in use */
> +		if (p->chan[i].status != COMP_STATE_INIT)
> +			count++;
> +	}
> +
> +	return count;
> +}
> +
>   /* acquire the specific DMA channel */
>   static int hda_dma_channel_get(struct dma *dma, int channel)
>   {
> @@ -406,6 +424,7 @@ static int hda_dma_probe(struct dma *dma)
>   const struct dma_ops hda_host_dma_ops = {
>   	.channel_get	= hda_dma_channel_get,
>   	.channel_put	= hda_dma_channel_put,
> +	.channel_status = hda_dma_channel_status,
>   	.start		= hda_dma_start,
>   	.stop		= hda_dma_stop,
>   	.copy		= hda_dma_copy,
> @@ -422,6 +441,7 @@ const struct dma_ops hda_host_dma_ops = {
>   const struct dma_ops hda_link_dma_ops = {
>   	.channel_get	= hda_dma_channel_get,
>   	.channel_put	= hda_dma_channel_put,
> +	.channel_status = hda_dma_channel_status,
>   	.start		= hda_dma_start,
>   	.stop		= hda_dma_stop,
>   	.copy		= hda_dma_copy,
> diff --git a/src/include/sof/dma.h b/src/include/sof/dma.h
> index 80ca880..1de9efc 100644
> --- a/src/include/sof/dma.h
> +++ b/src/include/sof/dma.h
> @@ -93,6 +93,7 @@ struct dma_ops {
>   
>   	int (*channel_get)(struct dma *dma, int req_channel);
>   	void (*channel_put)(struct dma *dma, int channel);
> +	int (*channel_status)(struct dma *dma);

get_free_channels()? channel_status() is  not explicit enough.

Thanks,
~Keyon

>   
>   	int (*start)(struct dma *dma, int channel);
>   	int (*stop)(struct dma *dma, int channel);
> @@ -178,6 +179,12 @@ static inline void dma_channel_put(struct dma *dma, int channel)
>   	dma->ops->channel_put(dma, channel);
>   }
>   
> +/* get the number of DMA channels in use */
> +static inline int dma_channel_status(struct dma *dma)
> +{
> +	return dma->ops->channel_status(dma);
> +}
> +
>   static inline int dma_set_cb(struct dma *dma, int channel, int type,
>   	void (*cb)(void *data, uint32_t type, struct dma_sg_elem *next), void *data)
>   {
>