| Message ID | 20170903224100.17893-8-stefan.bruens@rwth-aachen.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi, On 03/09/17 23:40, 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. > > Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de> > --- > drivers/dma/sun6i-dma.c | 35 ++++++++++++++++++++++++++++++++++- > 1 file changed, 34 insertions(+), 1 deletion(-) > > diff --git a/drivers/dma/sun6i-dma.c b/drivers/dma/sun6i-dma.c > index c69dadb853d2..bd4c2e4a759b 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) > @@ -1173,6 +1177,35 @@ 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; > + } > + > + if (sdc->num_pchans > DMA_MAX_CHANNELS) { > + dev_err(&pdev->dev, "Number of dma-channels out of range.\n"); > + return -EINVAL; > + } > + > + 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); Mmmh, is this mapping of "!sdc->max_request" -> DMA_CHAN_MAX_DRQ implemented somewhere else? Or is it just missing here: sdc->max_request = DMA_CHAN_MAX_DRQ; Otherwise this is looking good, thanks for picking up the DT property approach! Cheers, Andre. > + } > + > + if (sdc->max_request > DMA_CHAN_MAX_DRQ) { > + dev_err(&pdev->dev, "Value of dma-requests out of range.\n"); > + return -EINVAL; > + } > + > + /* > + * 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) >
On Montag, 4. September 2017 01:44:54 CEST André Przywara wrote: > Hi, > > On 03/09/17 23:40, 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. > > > > Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de> > > --- > > > > drivers/dma/sun6i-dma.c | 35 ++++++++++++++++++++++++++++++++++- > > 1 file changed, 34 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/dma/sun6i-dma.c b/drivers/dma/sun6i-dma.c > > index c69dadb853d2..bd4c2e4a759b 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) > > > > @@ -1173,6 +1177,35 @@ 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; > > + } > > + > > + if (sdc->num_pchans > DMA_MAX_CHANNELS) { > > + dev_err(&pdev->dev, "Number of dma-channels out of range.\n"); > > + return -EINVAL; > > + } > > + > > + 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); > > Mmmh, is this mapping of "!sdc->max_request" -> DMA_CHAN_MAX_DRQ > implemented somewhere else? Or is it just missing here: > sdc->max_request = DMA_CHAN_MAX_DRQ; Well spotted, that assignment is actually missing. With this line added, your comment for patch 8/10 should also be addressed (regarding the default value). > Otherwise this is looking good, thanks for picking up the DT property > approach! > > Cheers, > Andre. > Kind regards, Stefan
diff --git a/drivers/dma/sun6i-dma.c b/drivers/dma/sun6i-dma.c index c69dadb853d2..bd4c2e4a759b 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) @@ -1173,6 +1177,35 @@ 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; + } + + if (sdc->num_pchans > DMA_MAX_CHANNELS) { + dev_err(&pdev->dev, "Number of dma-channels out of range.\n"); + return -EINVAL; + } + + 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); + } + + if (sdc->max_request > DMA_CHAN_MAX_DRQ) { + dev_err(&pdev->dev, "Value of dma-requests out of range.\n"); + return -EINVAL; + } + + /* + * 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)
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> --- drivers/dma/sun6i-dma.c | 35 ++++++++++++++++++++++++++++++++++- 1 file changed, 34 insertions(+), 1 deletion(-)