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

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>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

1 files changed, 16 insertions, 7 deletions

diff --git a/drivers/dma/dw_dmac.c b/drivers/dma/dw_dmac.c
index 476e9c8fb6ca..c0c9370ddd3f 100644
--- a/drivers/dma/dw_dmac.c
+++ b/drivers/dma/dw_dmac.c
@@ -1600,13 +1600,6 @@ static int dw_probe(struct platform_device *pdev)
         int                     err;
         int                     i;
 
-        pdata = dev_get_platdata(&pdev->dev);
-        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 +1615,22 @@ static int dw_probe(struct platform_device *pdev)
         dw_params = dma_read_byaddr(regs, DW_PARAMS);
         autocfg = dw_params >> DW_PARAMS_EN & 0x1;
 
+        pdata = dev_get_platdata(&pdev->dev);
+        if (!pdata)
+                pdata = dw_dma_parse_dt(pdev);
+
+        if (!pdata && autocfg) {
+                pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
+                if (!pdata)
+                        return -ENOMEM;
+
+                /* Fill platform data with the default values */
+                pdata->is_private = true;
+                pdata->chan_allocation_order = CHAN_ALLOCATION_ASCENDING;
+                pdata->chan_priority = CHAN_PRIORITY_ASCENDING;
+        } else 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