atmel-mci: convert to dma_request_channel and down-level dma_slave

dma_request_channel provides an exclusive channel, so we no longer need to
pass slave data through dmaengine.

Cc: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

2 files changed, 6 insertions, 27 deletions

diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c
index 7a0594f24a3f..90aca505a1df 100644
--- a/drivers/dma/dmaengine.c
+++ b/drivers/dma/dmaengine.c
@@ -234,10 +234,6 @@ static void dma_client_chan_alloc(struct dma_client *client)
         list_for_each_entry(device, &dma_device_list, global_node) {
                 if (dma_has_cap(DMA_PRIVATE, device->cap_mask))
                         continue;
-                /* Does the client require a specific DMA controller? */
-                if (client->slave && client->slave->dma_dev
-                                && client->slave->dma_dev != device->dev)
-                        continue;
                 if (!dma_device_satisfies_mask(device, client->cap_mask))
                         continue;
 
@@ -613,10 +609,6 @@ void dma_async_client_register(struct dma_client *client)
         struct dma_chan *chan;
         int err;
 
-        /* validate client data */
-        BUG_ON(dma_has_cap(DMA_SLAVE, client->cap_mask) &&
-                !client->slave);
-
         mutex_lock(&dma_list_mutex);
         dmaengine_ref_count++;
 
diff --git a/drivers/dma/dw_dmac.c b/drivers/dma/dw_dmac.c
index 377dafa37a20..dbd50804e5d2 100644
--- a/drivers/dma/dw_dmac.c
+++ b/drivers/dma/dw_dmac.c
@@ -567,7 +567,7 @@ dwc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
         if (unlikely(!dws || !sg_len))
                 return NULL;
 
-        reg_width = dws->slave.reg_width;
+        reg_width = dws->reg_width;
         prev = first = NULL;
 
         sg_len = dma_map_sg(chan->dev.parent, sgl, sg_len, direction);
@@ -579,7 +579,7 @@ dwc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
                                 | DWC_CTLL_DST_FIX
                                 | DWC_CTLL_SRC_INC
                                 | DWC_CTLL_FC_M2P);
-                reg = dws->slave.tx_reg;
+                reg = dws->tx_reg;
                 for_each_sg(sgl, sg, sg_len, i) {
                         struct dw_desc  *desc;
                         u32             len;
@@ -625,7 +625,7 @@ dwc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
                                 | DWC_CTLL_SRC_FIX
                                 | DWC_CTLL_FC_P2M);
 
-                reg = dws->slave.rx_reg;
+                reg = dws->rx_reg;
                 for_each_sg(sgl, sg, sg_len, i) {
                         struct dw_desc  *desc;
                         u32             len;
@@ -764,7 +764,6 @@ static int dwc_alloc_chan_resources(struct dma_chan *chan,
         struct dw_dma_chan      *dwc = to_dw_dma_chan(chan);
         struct dw_dma           *dw = to_dw_dma(chan->device);
         struct dw_desc          *desc;
-        struct dma_slave        *slave;
         struct dw_dma_slave     *dws;
         int                     i;
         u32                     cfghi;
@@ -772,12 +771,6 @@ static int dwc_alloc_chan_resources(struct dma_chan *chan,
 
         dev_vdbg(&chan->dev, "alloc_chan_resources\n");
 
-        /* Channels doing slave DMA can only handle one client. */
-        if (dwc->dws || (client && client->slave)) {
-                if (chan->client_count)
-                        return -EBUSY;
-        }
-
         /* ASSERT:  channel is idle */
         if (dma_readl(dw, CH_EN) & dwc->mask) {
                 dev_dbg(&chan->dev, "DMA channel not idle?\n");
@@ -789,23 +782,17 @@ static int dwc_alloc_chan_resources(struct dma_chan *chan,
         cfghi = DWC_CFGH_FIFO_MODE;
         cfglo = 0;
 
-        slave = client->slave;
-        if (slave) {
+        dws = dwc->dws;
+        if (dws) {
                 /*
                  * We need controller-specific data to set up slave
                  * transfers.
                  */
-                BUG_ON(!slave->dma_dev || slave->dma_dev != dw->dma.dev);
-
-                dws = container_of(slave, struct dw_dma_slave, slave);
+                BUG_ON(!dws->dma_dev || dws->dma_dev != dw->dma.dev);
 
-                dwc->dws = dws;
                 cfghi = dws->cfg_hi;
                 cfglo = dws->cfg_lo;
-        } else {
-                dwc->dws = NULL;
         }
-
         channel_writel(dwc, CFG_LO, cfglo);
         channel_writel(dwc, CFG_HI, cfghi);