mmc: atmel-mci: convert to dma_request_slave_channel_compat()

Use generic DMA DT helper. Platforms booting with or without DT populated
are both supported.

Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Acked-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Chris Ball <cjb@laptop.org>

drivers/mmc/host/atmel-mci.c

@@ -2230,10 +2230,15 @@ static void __exit atmci_cleanup_slot(struct atmel_mci_slot *slot,
 	mmc_free_host(slot->mmc);
 }
 
-static bool atmci_filter(struct dma_chan *chan, void *slave)
+static bool atmci_filter(struct dma_chan *chan, void *pdata)
 {
-	struct mci_dma_data	*sl = slave;
+	struct mci_platform_data *sl_pdata = pdata;
+	struct mci_dma_data *sl;
 
+	if (!sl_pdata)
+		return false;
+
+	sl = sl_pdata->dma_slave;
 	if (sl && find_slave_dev(sl) == chan->device->dev) {
 		chan->private = slave_data_ptr(sl);
 		return true;
@@ -2245,24 +2250,18 @@ static bool atmci_filter(struct dma_chan *chan, void *slave)
 static bool atmci_configure_dma(struct atmel_mci *host)
 {
 	struct mci_platform_data	*pdata;
+	dma_cap_mask_t mask;
 
 	if (host == NULL)
 		return false;
 
 	pdata = host->pdev->dev.platform_data;
 
-	if (!pdata)
-		return false;
+	dma_cap_zero(mask);
+	dma_cap_set(DMA_SLAVE, mask);
 
-	if (pdata->dma_slave && find_slave_dev(pdata->dma_slave)) {
-		dma_cap_mask_t mask;
-
-		/* Try to grab a DMA channel */
-		dma_cap_zero(mask);
-		dma_cap_set(DMA_SLAVE, mask);
-		host->dma.chan =
-			dma_request_channel(mask, atmci_filter, pdata->dma_slave);
-	}
+	host->dma.chan = dma_request_slave_channel_compat(mask, atmci_filter, pdata,
+							  &host->pdev->dev, "rxtx");
 	if (!host->dma.chan) {
 		dev_warn(&host->pdev->dev, "no DMA channel available\n");
 		return false;