mmc: sh_mmcif: Factorize DMA channel request and configuration code

The channel request and configuration code is duplicated for the rx and
tx channels. Create a function that requests a single channel and call
it twice instead.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Chris Ball <cjb@laptop.org>

diff --git a/drivers/mmc/host/sh_mmcif.c b/drivers/mmc/host/sh_mmcif.c
index d032b080ac4de66311e390458629204332a6ca57..bebf2fe38ea034419ff6b63f08d95c2fe9648fff 100644 (file)
--- a/drivers/mmc/host/sh_mmcif.c
+++ b/drivers/mmc/host/sh_mmcif.c
@@ -381,73 +381,75 @@ static void sh_mmcif_start_dma_tx(struct sh_mmcif_host *host)
                desc, cookie);
 }
 
-static void sh_mmcif_request_dma(struct sh_mmcif_host *host,
-                                struct sh_mmcif_plat_data *pdata)
+static struct dma_chan *
+sh_mmcif_request_dma_one(struct sh_mmcif_host *host,
+                        struct sh_mmcif_plat_data *pdata,
+                        enum dma_transfer_direction direction)
 {
-       struct resource *res = platform_get_resource(host->pd, IORESOURCE_MEM, 0);
        struct dma_slave_config cfg;
+       struct dma_chan *chan;
+       unsigned int slave_id;
+       struct resource *res;
        dma_cap_mask_t mask;
        int ret;
 
-       host->dma_active = false;
-
-       if (pdata) {
-               if (pdata->slave_id_tx <= 0 || pdata->slave_id_rx <= 0)
-                       return;
-       } else if (!host->pd->dev.of_node) {
-               return;
-       }
-
-       /* We can only either use DMA for both Tx and Rx or not use it at all */
        dma_cap_zero(mask);
        dma_cap_set(DMA_SLAVE, mask);
 
-       host->chan_tx = dma_request_slave_channel_compat(mask, shdma_chan_filter,
-                               pdata ? (void *)pdata->slave_id_tx : NULL,
-                               &host->pd->dev, "tx");
-       dev_dbg(&host->pd->dev, "%s: TX: got channel %p\n", __func__,
-               host->chan_tx);
+       if (pdata)
+               slave_id = direction == DMA_MEM_TO_DEV
+                        ? pdata->slave_id_tx : pdata->slave_id_rx;
+       else
+               slave_id = 0;
 
-       if (!host->chan_tx)
-               return;
+       chan = dma_request_slave_channel_compat(mask, shdma_chan_filter,
+                               (void *)slave_id, &host->pd->dev,
+                               direction == DMA_MEM_TO_DEV ? "tx" : "rx");
+
+       dev_dbg(&host->pd->dev, "%s: %s: got channel %p\n", __func__,
+               direction == DMA_MEM_TO_DEV ? "TX" : "RX", chan);
+
+       if (!chan)
+               return NULL;
+
+       res = platform_get_resource(host->pd, IORESOURCE_MEM, 0);
 
        /* In the OF case the driver will get the slave ID from the DT */
-       if (pdata)
-               cfg.slave_id = pdata->slave_id_tx;
-       cfg.direction = DMA_MEM_TO_DEV;
+       cfg.slave_id = slave_id;
+       cfg.direction = direction;
        cfg.dst_addr = res->start + MMCIF_CE_DATA;
        cfg.src_addr = 0;
-       ret = dmaengine_slave_config(host->chan_tx, &cfg);
-       if (ret < 0)
-               goto ecfgtx;
+       ret = dmaengine_slave_config(chan, &cfg);
+       if (ret < 0) {
+               dma_release_channel(chan);
+               return NULL;
+       }
 
-       host->chan_rx = dma_request_slave_channel_compat(mask, shdma_chan_filter,
-                               pdata ? (void *)pdata->slave_id_rx : NULL,
-                               &host->pd->dev, "rx");
-       dev_dbg(&host->pd->dev, "%s: RX: got channel %p\n", __func__,
-               host->chan_rx);
+       return chan;
+}
 
-       if (!host->chan_rx)
-               goto erqrx;
+static void sh_mmcif_request_dma(struct sh_mmcif_host *host,
+                                struct sh_mmcif_plat_data *pdata)
+{
+       host->dma_active = false;
 
-       if (pdata)
-               cfg.slave_id = pdata->slave_id_rx;
-       cfg.direction = DMA_DEV_TO_MEM;
-       cfg.dst_addr = 0;
-       cfg.src_addr = res->start + MMCIF_CE_DATA;
-       ret = dmaengine_slave_config(host->chan_rx, &cfg);
-       if (ret < 0)
-               goto ecfgrx;
+       if (pdata) {
+               if (pdata->slave_id_tx <= 0 || pdata->slave_id_rx <= 0)
+                       return;
+       } else if (!host->pd->dev.of_node) {
+               return;
+       }
 
-       return;
+       /* We can only either use DMA for both Tx and Rx or not use it at all */
+       host->chan_tx = sh_mmcif_request_dma_one(host, pdata, DMA_MEM_TO_DEV);
+       if (!host->chan_tx)
+               return;
 
-ecfgrx:
-       dma_release_channel(host->chan_rx);
-       host->chan_rx = NULL;
-erqrx:
-ecfgtx:
-       dma_release_channel(host->chan_tx);
-       host->chan_tx = NULL;
+       host->chan_rx = sh_mmcif_request_dma_one(host, pdata, DMA_DEV_TO_MEM);
+       if (!host->chan_rx) {
+               dma_release_channel(host->chan_tx);
+               host->chan_tx = NULL;
+       }
 }
 
 static void sh_mmcif_release_dma(struct sh_mmcif_host *host)