The current code mixes three distinct operations when transforming
the slave config to register settings:

  1. special handling of DMA_SLAVE_BUSWIDTH_UNDEFINED, maxburst == 0
  2. range checking
  3. conversion of raw to register values

As the range checks depend on the specific SoC, move these out of the
conversion to distinct operations.

Signed-off-by: Stefan Brüns <stefan.bru...@rwth-aachen.de>
---
 drivers/dma/sun6i-dma.c | 58 +++++++++++++++++++++++++------------------------
 1 file changed, 30 insertions(+), 28 deletions(-)

diff --git a/drivers/dma/sun6i-dma.c b/drivers/dma/sun6i-dma.c
index f1a139f0102f..c5644bd0f91a 100644
--- a/drivers/dma/sun6i-dma.c
+++ b/drivers/dma/sun6i-dma.c
@@ -185,6 +185,8 @@ struct sun6i_dma_dev {
        struct sun6i_pchan      *pchans;
        struct sun6i_vchan      *vchans;
        const struct sun6i_dma_config *cfg;
+       u32                     src_burst_lengths;
+       u32                     dst_burst_lengths;
 };
 
 static struct device *chan2dev(struct dma_chan *chan)
@@ -270,10 +272,6 @@ static inline s8 convert_burst(u32 maxburst)
 
 static inline s8 convert_buswidth(enum dma_slave_buswidth addr_width)
 {
-       if ((addr_width < DMA_SLAVE_BUSWIDTH_1_BYTE) ||
-           (addr_width > DMA_SLAVE_BUSWIDTH_4_BYTES))
-               return -EINVAL;
-
        return addr_width >> 1;
 }
 
@@ -520,41 +518,43 @@ static int set_config(struct sun6i_dma_dev *sdev,
                        enum dma_transfer_direction direction,
                        u32 *p_cfg)
 {
+       enum dma_slave_buswidth src_addr_width, dst_addr_width;
+       u32 src_maxburst, dst_maxburst;
        s8 src_width, dst_width, src_burst, dst_burst;
 
+       src_addr_width = sconfig->src_addr_width;
+       dst_addr_width = sconfig->dst_addr_width;
+       src_maxburst = sconfig->src_maxburst;
+       dst_maxburst = sconfig->dst_maxburst;
+
        switch (direction) {
        case DMA_MEM_TO_DEV:
-               src_burst = convert_burst(sconfig->src_maxburst ?
-                                       sconfig->src_maxburst : 8);
-               src_width = convert_buswidth(sconfig->src_addr_width !=
-                                               DMA_SLAVE_BUSWIDTH_UNDEFINED ?
-                               sconfig->src_addr_width :
-                               DMA_SLAVE_BUSWIDTH_4_BYTES);
-               dst_burst = convert_burst(sconfig->dst_maxburst);
-               dst_width = convert_buswidth(sconfig->dst_addr_width);
+               if (src_addr_width == DMA_SLAVE_BUSWIDTH_UNDEFINED)
+                       src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
+               src_maxburst = src_maxburst ? src_maxburst : 8;
                break;
        case DMA_DEV_TO_MEM:
-               src_burst = convert_burst(sconfig->src_maxburst);
-               src_width = convert_buswidth(sconfig->src_addr_width);
-               dst_burst = convert_burst(sconfig->dst_maxburst ?
-                                       sconfig->dst_maxburst : 8);
-               dst_width = convert_buswidth(sconfig->dst_addr_width !=
-                                               DMA_SLAVE_BUSWIDTH_UNDEFINED ?
-                               sconfig->dst_addr_width :
-                               DMA_SLAVE_BUSWIDTH_4_BYTES);
+               if (dst_addr_width == DMA_SLAVE_BUSWIDTH_UNDEFINED)
+                       dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
+               dst_maxburst = dst_maxburst ? dst_maxburst : 8;
                break;
        default:
                return -EINVAL;
        }
 
-       if (src_burst < 0)
-               return src_burst;
-       if (src_width < 0)
-               return src_width;
-       if (dst_burst < 0)
-               return dst_burst;
-       if (dst_width < 0)
-               return dst_width;
+       if (!(BIT(src_addr_width) & sdev->slave.src_addr_widths))
+               return -EINVAL;
+       if (!(BIT(dst_addr_width) & sdev->slave.dst_addr_widths))
+               return -EINVAL;
+       if (!(BIT(src_maxburst) & sdev->src_burst_lengths))
+               return -EINVAL;
+       if (!(BIT(dst_maxburst) & sdev->dst_burst_lengths))
+               return -EINVAL;
+
+       src_width = convert_buswidth(src_addr_width);
+       dst_width = convert_buswidth(dst_addr_width);
+       dst_burst = convert_burst(dst_maxburst);
+       src_burst = convert_burst(src_maxburst);
 
        *p_cfg = DMA_CHAN_CFG_SRC_WIDTH(src_width) |
                DMA_CHAN_CFG_DST_WIDTH(dst_width);
@@ -1150,6 +1150,8 @@ static int sun6i_dma_probe(struct platform_device *pdev)
        sdc->slave.dst_addr_widths              = 
BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |
                                                  
BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |
                                                  
BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
+       sdc->src_burst_lengths                  = BIT(1) | BIT(8);
+       sdc->dst_burst_lengths                  = BIT(1) | BIT(8);
        sdc->slave.directions                   = BIT(DMA_DEV_TO_MEM) |
                                                  BIT(DMA_MEM_TO_DEV);
        sdc->slave.residue_granularity          = DMA_RESIDUE_GRANULARITY_BURST;
-- 
2.14.1

-- 
You received this message because you are subscribed to the Google Groups 
"linux-sunxi" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to linux-sunxi+unsubscr...@googlegroups.com.
For more options, visit https://groups.google.com/d/optout.

Reply via email to