[PATCH] dw_dmac: absence of pdata isn't critical when autocfg is set

[PATCH] dw_dmac: absence of pdata isn't critical when autocfg is set

[Andy Shevchenko]

The patch allows to probe the device when platform data is absent and hardware
auto configuration is enabled. In that case the default platform data is used
where the channel allocation order is set to ascending, channel priority is set
to ascending, and private property is set to true.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
 drivers/dma/dw_dmac.c |   15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/drivers/dma/dw_dmac.c b/drivers/dma/dw_dmac.c
index 2c8096d..0ec5c84 100644
--- a/drivers/dma/dw_dmac.c
+++ b/drivers/dma/dw_dmac.c
@@ -1585,6 +1585,12 @@ dw_dma_parse_dt(struct platform_device *pdev)
 }
 #endif
 
+static struct dw_dma_platform_data dw_dma_pdata = {
+	.is_private = true,
+	.chan_allocation_order = CHAN_ALLOCATION_ASCENDING,
+	.chan_priority = CHAN_PRIORITY_ASCENDING,
+};
+
 static int __devinit dw_probe(struct platform_device *pdev)
 {
 	struct dw_dma_platform_data *pdata;
@@ -1604,9 +1610,6 @@ static int __devinit dw_probe(struct platform_device *pdev)
 	if (!pdata)
 		pdata = dw_dma_parse_dt(pdev);
 
-	if (!pdata || pdata->nr_channels > DW_DMA_MAX_NR_CHANNELS)
-		return -EINVAL;
-
 	io = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	if (!io)
 		return -EINVAL;
@@ -1622,6 +1625,12 @@ static int __devinit dw_probe(struct platform_device *pdev)
 	dw_params = dma_read_byaddr(regs, DW_PARAMS);
 	autocfg = dw_params >> DW_PARAMS_EN & 0x1;
 
+	if (!pdata && autocfg)
+		pdata = &dw_dma_pdata;
+
+	if (!pdata || pdata->nr_channels > DW_DMA_MAX_NR_CHANNELS)
+		return -EINVAL;
+
 	if (autocfg)
 		nr_channels = (dw_params >> DW_PARAMS_NR_CHAN & 0x7) + 1;
 	else
-- 
1.7.10.4

Re: [PATCH] dw_dmac: absence of pdata isn't critical when autocfg is set

[viresh kumar]

On Mon, Nov 12, 2012 at 4:53 PM, Andy Shevchenko
<andriy.shevchenko@linux.intel.com> wrote:
> diff --git a/drivers/dma/dw_dmac.c b/drivers/dma/dw_dmac.c

>  static int __devinit dw_probe(struct platform_device *pdev)
>  {
>         struct dw_dma_platform_data *pdata;
> @@ -1604,9 +1610,6 @@ static int __devinit dw_probe(struct platform_device *pdev)
>         if (!pdata)
>                 pdata = dw_dma_parse_dt(pdev);
>
> -       if (!pdata || pdata->nr_channels > DW_DMA_MAX_NR_CHANNELS)
> -               return -EINVAL;
> -
>         io = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>         if (!io)
>                 return -EINVAL;
> @@ -1622,6 +1625,12 @@ static int __devinit dw_probe(struct platform_device *pdev)
>         dw_params = dma_read_byaddr(regs, DW_PARAMS);
>         autocfg = dw_params >> DW_PARAMS_EN & 0x1;
>
> +       if (!pdata && autocfg)
> +               pdata = &dw_dma_pdata;

Allocate it dynamically to support multiple controllers with different
configuration
in a SoC.

Re: [PATCH] dw_dmac: absence of pdata isn't critical when autocfg is set

[Andy Shevchenko]

On Mon, 2012-11-12 at 19:24 +0530, viresh kumar wrote: 
> On Mon, Nov 12, 2012 at 4:53 PM, Andy Shevchenko
> <andriy.shevchenko@linux.intel.com> wrote:
> > diff --git a/drivers/dma/dw_dmac.c b/drivers/dma/dw_dmac.c
> 
> >  static int __devinit dw_probe(struct platform_device *pdev)
> >  {
> >         struct dw_dma_platform_data *pdata;
> > @@ -1604,9 +1610,6 @@ static int __devinit dw_probe(struct platform_device *pdev)
> >         if (!pdata)
> >                 pdata = dw_dma_parse_dt(pdev);
> >
> > -       if (!pdata || pdata->nr_channels > DW_DMA_MAX_NR_CHANNELS)
> > -               return -EINVAL;
> > -
> >         io = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> >         if (!io)
> >                 return -EINVAL;
> > @@ -1622,6 +1625,12 @@ static int __devinit dw_probe(struct platform_device *pdev)
> >         dw_params = dma_read_byaddr(regs, DW_PARAMS);
> >         autocfg = dw_params >> DW_PARAMS_EN & 0x1;
> >
> > +       if (!pdata && autocfg)
> > +               pdata = &dw_dma_pdata;
> 
> Allocate it dynamically to support multiple controllers with different
> configuration
> in a SoC.

Like you did for device tree? No problem, but here is the question: what
the default values should be and where we can get them?


-- 
Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Intel Finland Oy

Re: [PATCH] dw_dmac: absence of pdata isn't critical when autocfg is set

[Viresh Kumar]

On 12 November 2012 19:28, Andy Shevchenko
<andriy.shevchenko@linux.intel.com> wrote:
> On Mon, 2012-11-12 at 19:24 +0530, viresh kumar wrote:

>> Allocate it dynamically to support multiple controllers with different
>> configuration
>> in a SoC.
>
> Like you did for device tree? No problem, but here is the question: what
> the default values should be and where we can get them?

Yes. Fill with the values you mentioned in your static definition :)

--
viresh

Re: [PATCH] dw_dmac: absence of pdata isn't critical when autocfg is set

[viresh kumar]

On Mon, Nov 12, 2012 at 4:53 PM, Andy Shevchenko
<andriy.shevchenko@linux.intel.com> wrote:
> +       if (!pdata && autocfg)
> +               pdata = &dw_dma_pdata;
> +
> +       if (!pdata || pdata->nr_channels > DW_DMA_MAX_NR_CHANNELS)
> +               return -EINVAL;
> +

Another thing: replace the  second if with else if :)