diff mbox series

[5/5] dmaengine: sprd: Add 'device_config' and 'device_prep_slave_sg' interfaces

Message ID 0a9fa618bd74e74c135ebee2e40b30d361c1d905.1523346135.git.baolin.wang@linaro.org
State New
Headers show
Series [1/5] dmaengine: sprd: Define the DMA transfer step type | expand

Commit Message

(Exiting) Baolin Wang April 10, 2018, 7:46 a.m. UTC 
This patch adds the 'device_config' and 'device_prep_slave_sg' interfaces
for users to configure DMA.

Signed-off-by: Baolin Wang <baolin.wang@linaro.org>

---
 drivers/dma/sprd-dma.c |   48 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 48 insertions(+)

-- 
1.7.9.5

Comments

Vinod Koul April 11, 2018, 9:40 a.m. UTC | #1 
On Tue, Apr 10, 2018 at 03:46:07PM +0800, Baolin Wang wrote:
> This patch adds the 'device_config' and 'device_prep_slave_sg' interfaces

> for users to configure DMA.

> 

> Signed-off-by: Baolin Wang <baolin.wang@linaro.org>

> ---

>  drivers/dma/sprd-dma.c |   48 ++++++++++++++++++++++++++++++++++++++++++++++++

>  1 file changed, 48 insertions(+)

> 

> diff --git a/drivers/dma/sprd-dma.c b/drivers/dma/sprd-dma.c

> index f8038de..c923fb0 100644

> --- a/drivers/dma/sprd-dma.c

> +++ b/drivers/dma/sprd-dma.c

> @@ -869,6 +869,52 @@ static int sprd_dma_config(struct dma_chan *chan, struct sprd_dma_desc *sdesc,

>  	return vchan_tx_prep(&schan->vc, &sdesc->vd, flags);

>  }

>  

> +static struct dma_async_tx_descriptor *

> +sprd_dma_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,

> +		       unsigned int sglen, enum dma_transfer_direction dir,

> +		       unsigned long flags, void *context)

> +{

> +	struct sprd_dma_chn *schan = to_sprd_dma_chan(chan);

> +	struct sprd_dma_config *slave_cfg = &schan->slave_cfg;

> +	struct sprd_dma_desc *sdesc;

> +	struct scatterlist *sg;

> +	int ret, i;

> +

> +	/* TODO: now we only support one sg for each DMA configuration. */

> +	if (!is_slave_direction(slave_cfg->config.direction) || sglen > 1)


the slave direction check seems wrong to me. .device_config shall give you
dma_slave_config. You should check here if dir passed is slave or not. If
you want to check parameters in slave_config then please use .device_config

> +		return NULL;

> +

> +	sdesc = kzalloc(sizeof(*sdesc), GFP_NOWAIT);

> +	if (!sdesc)

> +		return NULL;

> +

> +	for_each_sg(sgl, sg, sglen, i) {

> +		if (slave_cfg->config.direction == DMA_MEM_TO_DEV)

> +			slave_cfg->config.src_addr = sg_dma_address(sg);


Nope slave_config specifies peripheral address and not memory one passed here

-- 
~Vinod
(Exiting) Baolin Wang April 11, 2018, 10:51 a.m. UTC | #2 
Hi Vinod,

On 11 April 2018 at 17:40, Vinod Koul <vinod.koul@intel.com> wrote:
> On Tue, Apr 10, 2018 at 03:46:07PM +0800, Baolin Wang wrote:

>> This patch adds the 'device_config' and 'device_prep_slave_sg' interfaces

>> for users to configure DMA.

>>

>> Signed-off-by: Baolin Wang <baolin.wang@linaro.org>

>> ---

>>  drivers/dma/sprd-dma.c |   48 ++++++++++++++++++++++++++++++++++++++++++++++++

>>  1 file changed, 48 insertions(+)

>>

>> diff --git a/drivers/dma/sprd-dma.c b/drivers/dma/sprd-dma.c

>> index f8038de..c923fb0 100644

>> --- a/drivers/dma/sprd-dma.c

>> +++ b/drivers/dma/sprd-dma.c

>> @@ -869,6 +869,52 @@ static int sprd_dma_config(struct dma_chan *chan, struct sprd_dma_desc *sdesc,

>>       return vchan_tx_prep(&schan->vc, &sdesc->vd, flags);

>>  }

>>

>> +static struct dma_async_tx_descriptor *

>> +sprd_dma_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,

>> +                    unsigned int sglen, enum dma_transfer_direction dir,

>> +                    unsigned long flags, void *context)

>> +{

>> +     struct sprd_dma_chn *schan = to_sprd_dma_chan(chan);

>> +     struct sprd_dma_config *slave_cfg = &schan->slave_cfg;

>> +     struct sprd_dma_desc *sdesc;

>> +     struct scatterlist *sg;

>> +     int ret, i;

>> +

>> +     /* TODO: now we only support one sg for each DMA configuration. */

>> +     if (!is_slave_direction(slave_cfg->config.direction) || sglen > 1)

>

> the slave direction check seems wrong to me. .device_config shall give you

> dma_slave_config. You should check here if dir passed is slave or not. If

> you want to check parameters in slave_config then please use .device_config


Correct. Sorry I missed this and I will fix it in next version.

>

>> +             return NULL;

>> +

>> +     sdesc = kzalloc(sizeof(*sdesc), GFP_NOWAIT);

>> +     if (!sdesc)

>> +             return NULL;

>> +

>> +     for_each_sg(sgl, sg, sglen, i) {

>> +             if (slave_cfg->config.direction == DMA_MEM_TO_DEV)

>> +                     slave_cfg->config.src_addr = sg_dma_address(sg);

>

> Nope slave_config specifies peripheral address and not memory one passed here


OK. Thanks for your comments.

-- 
Baolin.wang
Best Regards
Lars-Peter Clausen April 17, 2018, 10:45 a.m. UTC | #3 
On 04/10/2018 09:46 AM, Baolin Wang wrote:
[...]
> +static int sprd_dma_slave_config(struct dma_chan *chan,

> +				 struct dma_slave_config *config)

> +{

> +	struct sprd_dma_chn *schan = to_sprd_dma_chan(chan);

> +	struct sprd_dma_config *slave_cfg =

> +		container_of(config, struct sprd_dma_config, config);

> +


Please do not overload standard API with custom semantics. This makes the
driver incompatible to the API and negates the whole idea of having a common
API. E.g. this will crash when somebody passes a normal dma_slave_config
struct to this function.

> +	memcpy(&schan->slave_cfg, slave_cfg, sizeof(*slave_cfg));

> +	return 0;

> +}
(Exiting) Baolin Wang April 18, 2018, 5:40 a.m. UTC | #4 
On 17 April 2018 at 18:45, Lars-Peter Clausen <lars@metafoo.de> wrote:
> On 04/10/2018 09:46 AM, Baolin Wang wrote:

> [...]

>> +static int sprd_dma_slave_config(struct dma_chan *chan,

>> +                              struct dma_slave_config *config)

>> +{

>> +     struct sprd_dma_chn *schan = to_sprd_dma_chan(chan);

>> +     struct sprd_dma_config *slave_cfg =

>> +             container_of(config, struct sprd_dma_config, config);

>> +

>

> Please do not overload standard API with custom semantics. This makes the

> driver incompatible to the API and negates the whole idea of having a common

> API. E.g. this will crash when somebody passes a normal dma_slave_config

> struct to this function.

>


Yes, we have discussed with Vinod how to use 'dma_slave_config' to
reach our requirements. Thanks for your comments.

-- 
Baolin.wang
Best Regards
diff mbox series

Patch

diff --git a/drivers/dma/sprd-dma.c b/drivers/dma/sprd-dma.c
index f8038de..c923fb0 100644
--- a/drivers/dma/sprd-dma.c
+++ b/drivers/dma/sprd-dma.c
@@ -869,6 +869,52 @@  static int sprd_dma_config(struct dma_chan *chan, struct sprd_dma_desc *sdesc,
 	return vchan_tx_prep(&schan->vc, &sdesc->vd, flags);
 }
 
+static struct dma_async_tx_descriptor *
+sprd_dma_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
+		       unsigned int sglen, enum dma_transfer_direction dir,
+		       unsigned long flags, void *context)
+{
+	struct sprd_dma_chn *schan = to_sprd_dma_chan(chan);
+	struct sprd_dma_config *slave_cfg = &schan->slave_cfg;
+	struct sprd_dma_desc *sdesc;
+	struct scatterlist *sg;
+	int ret, i;
+
+	/* TODO: now we only support one sg for each DMA configuration. */
+	if (!is_slave_direction(slave_cfg->config.direction) || sglen > 1)
+		return NULL;
+
+	sdesc = kzalloc(sizeof(*sdesc), GFP_NOWAIT);
+	if (!sdesc)
+		return NULL;
+
+	for_each_sg(sgl, sg, sglen, i) {
+		if (slave_cfg->config.direction == DMA_MEM_TO_DEV)
+			slave_cfg->config.src_addr = sg_dma_address(sg);
+		else
+			slave_cfg->config.dst_addr = sg_dma_address(sg);
+	}
+
+	ret = sprd_dma_config(chan, sdesc, slave_cfg);
+	if (ret) {
+		kfree(sdesc);
+		return NULL;
+	}
+
+	return vchan_tx_prep(&schan->vc, &sdesc->vd, flags);
+}
+
+static int sprd_dma_slave_config(struct dma_chan *chan,
+				 struct dma_slave_config *config)
+{
+	struct sprd_dma_chn *schan = to_sprd_dma_chan(chan);
+	struct sprd_dma_config *slave_cfg =
+		container_of(config, struct sprd_dma_config, config);
+
+	memcpy(&schan->slave_cfg, slave_cfg, sizeof(*slave_cfg));
+	return 0;
+}
+
 static int sprd_dma_pause(struct dma_chan *chan)
 {
 	struct sprd_dma_chn *schan = to_sprd_dma_chan(chan);
@@ -996,6 +1042,8 @@  static int sprd_dma_probe(struct platform_device *pdev)
 	sdev->dma_dev.device_tx_status = sprd_dma_tx_status;
 	sdev->dma_dev.device_issue_pending = sprd_dma_issue_pending;
 	sdev->dma_dev.device_prep_dma_memcpy = sprd_dma_prep_dma_memcpy;
+	sdev->dma_dev.device_prep_slave_sg = sprd_dma_prep_slave_sg;
+	sdev->dma_dev.device_config = sprd_dma_slave_config;
 	sdev->dma_dev.device_pause = sprd_dma_pause;
 	sdev->dma_dev.device_resume = sprd_dma_resume;
 	sdev->dma_dev.device_terminate_all = sprd_dma_terminate_all;