DMA: PL08x: avoid recalculating cctl at each prepare
[pandora-kernel.git] / drivers / dma / amba-pl08x.c
index 1c641bf..a84db8b 100644 (file)
@@ -1095,15 +1095,53 @@ static const struct burst_table burst_sizes[] = {
        },
 };
 
+/*
+ * Given the source and destination available bus masks, select which
+ * will be routed to each port.  We try to have source and destination
+ * on separate ports, but always respect the allowable settings.
+ */
+static u32 pl08x_select_bus(u8 src, u8 dst)
+{
+       u32 cctl = 0;
+
+       if (!(dst & PL08X_AHB1) || ((dst & PL08X_AHB2) && (src & PL08X_AHB1)))
+               cctl |= PL080_CONTROL_DST_AHB2;
+       if (!(src & PL08X_AHB1) || ((src & PL08X_AHB2) && !(dst & PL08X_AHB2)))
+               cctl |= PL080_CONTROL_SRC_AHB2;
+
+       return cctl;
+}
+
+static u32 pl08x_cctl(u32 cctl)
+{
+       cctl &= ~(PL080_CONTROL_SRC_AHB2 | PL080_CONTROL_DST_AHB2 |
+                 PL080_CONTROL_SRC_INCR | PL080_CONTROL_DST_INCR |
+                 PL080_CONTROL_PROT_MASK);
+
+       /* Access the cell in privileged mode, non-bufferable, non-cacheable */
+       return cctl | PL080_CONTROL_PROT_SYS;
+}
+
+static u32 pl08x_width(enum dma_slave_buswidth width)
+{
+       switch (width) {
+       case DMA_SLAVE_BUSWIDTH_1_BYTE:
+               return PL080_WIDTH_8BIT;
+       case DMA_SLAVE_BUSWIDTH_2_BYTES:
+               return PL080_WIDTH_16BIT;
+       case DMA_SLAVE_BUSWIDTH_4_BYTES:
+               return PL080_WIDTH_32BIT;
+       }
+       return ~0;
+}
+
 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;
-       struct pl08x_channel_data *cd = plchan->cd;
        enum dma_slave_buswidth addr_width;
-       dma_addr_t addr;
-       u32 maxburst;
+       u32 width, maxburst;
        u32 cctl = 0;
        int i;
 
@@ -1113,11 +1151,9 @@ static int dma_set_runtime_config(struct dma_chan *chan,
        /* Transfer direction */
        plchan->runtime_direction = config->direction;
        if (config->direction == DMA_TO_DEVICE) {
-               addr = config->dst_addr;
                addr_width = config->dst_addr_width;
                maxburst = config->dst_maxburst;
        } else if (config->direction == DMA_FROM_DEVICE) {
-               addr = config->src_addr;
                addr_width = config->src_addr_width;
                maxburst = config->src_maxburst;
        } else {
@@ -1126,25 +1162,16 @@ static int dma_set_runtime_config(struct dma_chan *chan,
                return -EINVAL;
        }
 
-       switch (addr_width) {
-       case DMA_SLAVE_BUSWIDTH_1_BYTE:
-               cctl |= (PL080_WIDTH_8BIT << PL080_CONTROL_SWIDTH_SHIFT) |
-                       (PL080_WIDTH_8BIT << PL080_CONTROL_DWIDTH_SHIFT);
-               break;
-       case DMA_SLAVE_BUSWIDTH_2_BYTES:
-               cctl |= (PL080_WIDTH_16BIT << PL080_CONTROL_SWIDTH_SHIFT) |
-                       (PL080_WIDTH_16BIT << PL080_CONTROL_DWIDTH_SHIFT);
-               break;
-       case DMA_SLAVE_BUSWIDTH_4_BYTES:
-               cctl |= (PL080_WIDTH_32BIT << PL080_CONTROL_SWIDTH_SHIFT) |
-                       (PL080_WIDTH_32BIT << PL080_CONTROL_DWIDTH_SHIFT);
-               break;
-       default:
+       width = pl08x_width(addr_width);
+       if (width == ~0) {
                dev_err(&pl08x->adev->dev,
                        "bad runtime_config: alien address width\n");
                return -EINVAL;
        }
 
+       cctl |= width << PL080_CONTROL_SWIDTH_SHIFT;
+       cctl |= width << PL080_CONTROL_DWIDTH_SHIFT;
+
        /*
         * Now decide on a maxburst:
         * If this channel will only request single transfers, set this
@@ -1161,10 +1188,17 @@ static int dma_set_runtime_config(struct dma_chan *chan,
                cctl |= burst_sizes[i].reg;
        }
 
-       plchan->runtime_addr = addr;
-
-       /* Modify the default channel data to fit PrimeCell request */
-       cd->cctl = cctl;
+       if (plchan->runtime_direction == DMA_FROM_DEVICE) {
+               plchan->src_addr = config->src_addr;
+               plchan->src_cctl = pl08x_cctl(cctl) | PL080_CONTROL_DST_INCR |
+                       pl08x_select_bus(plchan->cd->periph_buses,
+                                        pl08x->mem_buses);
+       } else {
+               plchan->dst_addr = config->dst_addr;
+               plchan->dst_cctl = pl08x_cctl(cctl) | PL080_CONTROL_SRC_INCR |
+                       pl08x_select_bus(pl08x->mem_buses,
+                                        plchan->cd->periph_buses);
+       }
 
        dev_dbg(&pl08x->adev->dev,
                "configured channel %s (%s) for %s, data width %d, "
@@ -1264,23 +1298,6 @@ static int pl08x_prep_channel_resources(struct pl08x_dma_chan *plchan,
        return 0;
 }
 
-/*
- * Given the source and destination available bus masks, select which
- * will be routed to each port.  We try to have source and destination
- * on separate ports, but always respect the allowable settings.
- */
-static u32 pl08x_select_bus(struct pl08x_driver_data *pl08x, u8 src, u8 dst)
-{
-       u32 cctl = 0;
-
-       if (!(dst & PL08X_AHB1) || ((dst & PL08X_AHB2) && (src & PL08X_AHB1)))
-               cctl |= PL080_CONTROL_DST_AHB2;
-       if (!(src & PL08X_AHB1) || ((src & PL08X_AHB2) && !(dst & PL08X_AHB2)))
-               cctl |= PL080_CONTROL_SRC_AHB2;
-
-       return cctl;
-}
-
 static struct pl08x_txd *pl08x_get_txd(struct pl08x_dma_chan *plchan,
        unsigned long flags)
 {
@@ -1332,8 +1349,8 @@ static struct dma_async_tx_descriptor *pl08x_prep_dma_memcpy(
        txd->cctl |= PL080_CONTROL_SRC_INCR | PL080_CONTROL_DST_INCR;
 
        if (pl08x->vd->dualmaster)
-               txd->cctl |= pl08x_select_bus(pl08x,
-                                       pl08x->mem_buses, pl08x->mem_buses);
+               txd->cctl |= pl08x_select_bus(pl08x->mem_buses,
+                                             pl08x->mem_buses);
 
        ret = pl08x_prep_channel_resources(plchan, txd);
        if (ret)
@@ -1350,7 +1367,6 @@ static struct dma_async_tx_descriptor *pl08x_prep_slave_sg(
        struct pl08x_dma_chan *plchan = to_pl08x_chan(chan);
        struct pl08x_driver_data *pl08x = plchan->host;
        struct pl08x_txd *txd;
-       u8 src_buses, dst_buses;
        int ret;
 
        /*
@@ -1384,42 +1400,22 @@ static struct dma_async_tx_descriptor *pl08x_prep_slave_sg(
        txd->direction = direction;
        txd->len = sgl->length;
 
-       txd->cctl = plchan->cd->cctl &
-                       ~(PL080_CONTROL_SRC_AHB2 | PL080_CONTROL_DST_AHB2 |
-                         PL080_CONTROL_SRC_INCR | PL080_CONTROL_DST_INCR |
-                         PL080_CONTROL_PROT_MASK);
-
-       /* Access the cell in privileged mode, non-bufferable, non-cacheable */
-       txd->cctl |= PL080_CONTROL_PROT_SYS;
-
        if (direction == DMA_TO_DEVICE) {
                txd->ccfg |= PL080_FLOW_MEM2PER << PL080_CONFIG_FLOW_CONTROL_SHIFT;
-               txd->cctl |= PL080_CONTROL_SRC_INCR;
+               txd->cctl = plchan->dst_cctl;
                txd->src_addr = sgl->dma_address;
-               if (plchan->runtime_addr)
-                       txd->dst_addr = plchan->runtime_addr;
-               else
-                       txd->dst_addr = plchan->cd->addr;
-               src_buses = pl08x->mem_buses;
-               dst_buses = plchan->cd->periph_buses;
+               txd->dst_addr = plchan->dst_addr;
        } else if (direction == DMA_FROM_DEVICE) {
                txd->ccfg |= PL080_FLOW_PER2MEM << PL080_CONFIG_FLOW_CONTROL_SHIFT;
-               txd->cctl |= PL080_CONTROL_DST_INCR;
-               if (plchan->runtime_addr)
-                       txd->src_addr = plchan->runtime_addr;
-               else
-                       txd->src_addr = plchan->cd->addr;
+               txd->cctl = plchan->src_cctl;
+               txd->src_addr = plchan->src_addr;
                txd->dst_addr = sgl->dma_address;
-               src_buses = plchan->cd->periph_buses;
-               dst_buses = pl08x->mem_buses;
        } else {
                dev_err(&pl08x->adev->dev,
                        "%s direction unsupported\n", __func__);
                return NULL;
        }
 
-       txd->cctl |= pl08x_select_bus(pl08x, src_buses, dst_buses);
-
        ret = pl08x_prep_channel_resources(plchan, txd);
        if (ret)
                return NULL;
@@ -1670,6 +1666,20 @@ static irqreturn_t pl08x_irq(int irq, void *dev)
        return mask ? IRQ_HANDLED : IRQ_NONE;
 }
 
+static void pl08x_dma_slave_init(struct pl08x_dma_chan *chan)
+{
+       u32 cctl = pl08x_cctl(chan->cd->cctl);
+
+       chan->slave = true;
+       chan->name = chan->cd->bus_id;
+       chan->src_addr = chan->cd->addr;
+       chan->dst_addr = chan->cd->addr;
+       chan->src_cctl = cctl | PL080_CONTROL_DST_INCR |
+               pl08x_select_bus(chan->cd->periph_buses, chan->host->mem_buses);
+       chan->dst_cctl = cctl | PL080_CONTROL_SRC_INCR |
+               pl08x_select_bus(chan->host->mem_buses, chan->cd->periph_buses);
+}
+
 /*
  * Initialise the DMAC memcpy/slave channels.
  * Make a local wrapper to hold required data
@@ -1701,9 +1711,8 @@ static int pl08x_dma_init_virtual_channels(struct pl08x_driver_data *pl08x,
                chan->state = PL08X_CHAN_IDLE;
 
                if (slave) {
-                       chan->slave = true;
-                       chan->name = pl08x->pd->slave_channels[i].bus_id;
                        chan->cd = &pl08x->pd->slave_channels[i];
+                       pl08x_dma_slave_init(chan);
                } else {
                        chan->cd = &pl08x->pd->memcpy_channel;
                        chan->name = kasprintf(GFP_KERNEL, "memcpy%d", i);