dmaengine: PL08x: extract function to to generate cctl values

Extract the functionality from dma_slave_config to generate the cctl
values for a given bus width and burst size.  This allows us to use
this elsewhere in the driver, namely the prepare functions.

Acked-by: Linus Walleij <linus.walleij@linaro.org>
Tested-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 32 insertions, 21 deletions

diff --git a/drivers/dma/amba-pl08x.c b/drivers/dma/amba-pl08x.c
index bd51a44746b..fde801f787c 100644
--- a/drivers/dma/amba-pl08x.c
+++ b/drivers/dma/amba-pl08x.c
@@ -1207,14 +1207,40 @@ static u32 pl08x_burst(u32 maxburst)
         return burst_sizes[i].reg;
 }
 
+static u32 pl08x_get_cctl(struct pl08x_dma_chan *plchan,
+        enum dma_slave_buswidth addr_width, u32 maxburst)
+{
+        u32 width, burst, cctl = 0;
+
+        width = pl08x_width(addr_width);
+        if (width == ~0)
+                return ~0;
+
+        cctl |= width << PL080_CONTROL_SWIDTH_SHIFT;
+        cctl |= width << PL080_CONTROL_DWIDTH_SHIFT;
+
+        /*
+         * If this channel will only request single transfers, set this
+         * down to ONE element.  Also select one element if no maxburst
+         * is specified.
+         */
+        if (plchan->cd->single)
+                maxburst = 1;
+
+        burst = pl08x_burst(maxburst);
+        cctl |= burst << PL080_CONTROL_SB_SIZE_SHIFT;
+        cctl |= burst << PL080_CONTROL_DB_SIZE_SHIFT;
+
+        return pl08x_cctl(cctl);
+}
+
 static int dma_set_runtime_config(struct dma_chan *chan,
                                   struct dma_slave_config *config)
 {
         struct pl08x_dma_chan *plchan = to_pl08x_chan(chan);
         struct pl08x_driver_data *pl08x = plchan->host;
         enum dma_slave_buswidth addr_width;
-        u32 width, burst, maxburst;
-        u32 cctl = 0;
+        u32 maxburst, cctl = 0;
 
         if (!plchan->slave)
                 return -EINVAL;
@@ -1233,8 +1259,8 @@ static int dma_set_runtime_config(struct dma_chan *chan,
                 return -EINVAL;
         }
 
-        width = pl08x_width(addr_width);
-        if (width == ~0) {
+        cctl = pl08x_get_cctl(plchan, addr_width, maxburst);
+        if (cctl == ~0) {
                 dev_err(&pl08x->adev->dev,
                         "bad runtime_config: alien address width\n");
                 return -EINVAL;
@@ -1242,25 +1268,10 @@ static int dma_set_runtime_config(struct dma_chan *chan,
 
         plchan->cfg = *config;
 
-        cctl |= width << PL080_CONTROL_SWIDTH_SHIFT;
-        cctl |= width << PL080_CONTROL_DWIDTH_SHIFT;
-
-        /*
-         * If this channel will only request single transfers, set this
-         * down to ONE element.  Also select one element if no maxburst
-         * is specified.
-         */
-        if (plchan->cd->single)
-                maxburst = 1;
-
-        burst = pl08x_burst(maxburst);
-        cctl |= burst << PL080_CONTROL_SB_SIZE_SHIFT;
-        cctl |= burst << PL080_CONTROL_DB_SIZE_SHIFT;
-
         if (plchan->runtime_direction == DMA_DEV_TO_MEM) {
-                plchan->src_cctl = pl08x_cctl(cctl);
+                plchan->src_cctl = cctl;
         } else {
-                plchan->dst_cctl = pl08x_cctl(cctl);
+                plchan->dst_cctl = cctl;
         }
 
         dev_dbg(&pl08x->adev->dev,