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>

1 files changed, 51 insertions, 49 deletions

diff --git a/drivers/mmc/host/sh_mmcif.c b/drivers/mmc/host/sh_mmcif.c
index d032b080ac4d..bebf2fe38ea0 100644
--- 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)