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[v4,07/11] dmaengine: sun6i: Retrieve channel count/max request from devicetree

Message ID 6277478a-601a-48b0-8e1f-1d309049d4f4@rwthex-w2-a.rwth-ad.de
State New
Headers show
Series [v4,01/11] dmaengine: sun6i: Correct setting of clock autogating register for A83T/H3 | expand

Commit Message

Stefan Brüns Sept. 28, 2017, 1:49 a.m. UTC 
To avoid introduction of a new compatible for each small SoC/DMA controller
variation, move the definition of the channel count to the devicetree.

The number of vchans is no longer explicit, but limited by the highest
port/DMA request number. The result is a slight overallocation for SoCs
with a sparse port mapping.

Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>

---

Changes in v4:
- remove range checks for dma-channels/dma-requests DT properties

Changes in v3: None
Changes in v2:
- Set default number of dma-request if not provided in config or devicetree

 drivers/dma/sun6i-dma.c | 27 ++++++++++++++++++++++++++-
 1 file changed, 26 insertions(+), 1 deletion(-)

Comments

Vinod Koul Oct. 16, 2017, 7:02 a.m. UTC | #1 
On Thu, Sep 28, 2017 at 03:49:24AM +0200, Stefan Brüns wrote:
> To avoid introduction of a new compatible for each small SoC/DMA controller
> variation, move the definition of the channel count to the devicetree.
> 
> The number of vchans is no longer explicit, but limited by the highest
> port/DMA request number. The result is a slight overallocation for SoCs
> with a sparse port mapping.

This doesnt apply for me, please check
Stefan Brüns Oct. 16, 2017, 2:21 p.m. UTC | #2 
On Montag, 16. Oktober 2017 09:02:17 CEST Vinod Koul wrote:
> On Thu, Sep 28, 2017 at 03:49:24AM +0200, Stefan Brüns wrote:
> > To avoid introduction of a new compatible for each small SoC/DMA
> > controller
> > variation, move the definition of the channel count to the devicetree.
> > 
> > The number of vchans is no longer explicit, but limited by the highest
> > port/DMA request number. The result is a slight overallocation for SoCs
> > with a sparse port mapping.
> 
> This doesnt apply for me, please check

The hunk below fails after https://git.kernel.org/pub/scm/linux/kernel/git/
vkoul/slave-dma.git/commit/?h=topic/
sun&id=8f3b00347bf075fb457f90ce76573615f567e7bc
, which removed the "const struct of_device_id *device;" declaration.


> diff --git a/drivers/dma/sun6i-dma.c b/drivers/dma/sun6i-dma.c
> index 7fce976a13d8..b5906da2a975 100644
> --- a/drivers/dma/sun6i-dma.c
> +++ b/drivers/dma/sun6i-dma.c
> @@ -42,6 +42,9 @@
...
> @@ -1155,6 +1159,7 @@ MODULE_DEVICE_TABLE(of, sun6i_dma_match);
>  static int sun6i_dma_probe(struct platform_device *pdev)
>  {
>  	const struct of_device_id *device;
> +	struct device_node *np = pdev->dev.of_node;
>  	struct sun6i_dma_dev *sdc;
>  	struct resource *res;
>  	int ret, i;

Can you fix this up, or should I send a new version of this patch?

Kind regards,

Stefan
Vinod Koul Oct. 16, 2017, 5:15 p.m. UTC | #3 
On Mon, Oct 16, 2017 at 02:21:02PM +0000, Brüns, Stefan wrote:
> On Montag, 16. Oktober 2017 09:02:17 CEST Vinod Koul wrote:
> > On Thu, Sep 28, 2017 at 03:49:24AM +0200, Stefan Brüns wrote:
> > > To avoid introduction of a new compatible for each small SoC/DMA
> > > controller
> > > variation, move the definition of the channel count to the devicetree.
> > > 
> > > The number of vchans is no longer explicit, but limited by the highest
> > > port/DMA request number. The result is a slight overallocation for SoCs
> > > with a sparse port mapping.
> > 
> > This doesnt apply for me, please check
> 
> The hunk below fails after https://git.kernel.org/pub/scm/linux/kernel/git/
> vkoul/slave-dma.git/commit/?h=topic/
> sun&id=8f3b00347bf075fb457f90ce76573615f567e7bc
> , which removed the "const struct of_device_id *device;" declaration.
> 
> 
> > diff --git a/drivers/dma/sun6i-dma.c b/drivers/dma/sun6i-dma.c
> > index 7fce976a13d8..b5906da2a975 100644
> > --- a/drivers/dma/sun6i-dma.c
> > +++ b/drivers/dma/sun6i-dma.c
> > @@ -42,6 +42,9 @@
> ..
> > @@ -1155,6 +1159,7 @@ MODULE_DEVICE_TABLE(of, sun6i_dma_match);
> >  static int sun6i_dma_probe(struct platform_device *pdev)
> >  {
> >  	const struct of_device_id *device;
> > +	struct device_node *np = pdev->dev.of_node;
> >  	struct sun6i_dma_dev *sdc;
> >  	struct resource *res;
> >  	int ret, i;
> 
> Can you fix this up, or should I send a new version of this patch?

rebased one please
diff mbox series

Patch

diff --git a/drivers/dma/sun6i-dma.c b/drivers/dma/sun6i-dma.c
index 7fce976a13d8..b5906da2a975 100644
--- a/drivers/dma/sun6i-dma.c
+++ b/drivers/dma/sun6i-dma.c
@@ -42,6 +42,9 @@ 
 
 #define DMA_STAT		0x30
 
+/* Offset between DMA_IRQ_EN and DMA_IRQ_STAT limits number of channels */
+#define DMA_MAX_CHANNELS	(DMA_IRQ_CHAN_NR * 0x10 / 4)
+
 /*
  * sun8i specific registers
  */
@@ -65,7 +68,8 @@ 
 #define DMA_CHAN_LLI_ADDR	0x08
 
 #define DMA_CHAN_CUR_CFG	0x0c
-#define DMA_CHAN_CFG_SRC_DRQ(x)		((x) & 0x1f)
+#define DMA_CHAN_MAX_DRQ		0x1f
+#define DMA_CHAN_CFG_SRC_DRQ(x)		((x) & DMA_CHAN_MAX_DRQ)
 #define DMA_CHAN_CFG_SRC_IO_MODE	BIT(5)
 #define DMA_CHAN_CFG_SRC_LINEAR_MODE	(0 << 5)
 #define DMA_CHAN_CFG_SRC_BURST_A31(x)	(((x) & 0x3) << 7)
@@ -1155,6 +1159,7 @@  MODULE_DEVICE_TABLE(of, sun6i_dma_match);
 static int sun6i_dma_probe(struct platform_device *pdev)
 {
 	const struct of_device_id *device;
+	struct device_node *np = pdev->dev.of_node;
 	struct sun6i_dma_dev *sdc;
 	struct resource *res;
 	int ret, i;
@@ -1230,6 +1235,26 @@  static int sun6i_dma_probe(struct platform_device *pdev)
 	sdc->num_vchans = sdc->cfg->nr_max_vchans;
 	sdc->max_request = sdc->cfg->nr_max_requests;
 
+	ret = of_property_read_u32(np, "dma-channels", &sdc->num_pchans);
+	if (ret && !sdc->num_pchans) {
+		dev_err(&pdev->dev, "Can't get dma-channels.\n");
+		return ret;
+	}
+
+	ret = of_property_read_u32(np, "dma-requests", &sdc->max_request);
+	if (ret && !sdc->max_request) {
+		dev_info(&pdev->dev, "Missing dma-requests, using %u.\n",
+			 DMA_CHAN_MAX_DRQ);
+		sdc->max_request = DMA_CHAN_MAX_DRQ;
+	}
+
+	/*
+	 * If the number of vchans is not specified, derive it from the
+	 * highest port number, at most one channel per port and direction.
+	 */
+	if (!sdc->num_vchans)
+		sdc->num_vchans = 2 * (sdc->max_request + 1);
+
 	sdc->pchans = devm_kcalloc(&pdev->dev, sdc->num_pchans,
 				   sizeof(struct sun6i_pchan), GFP_KERNEL);
 	if (!sdc->pchans)