mmc: sdhi/tmio: add DT DMA support

Add support for initialising DMA from the Device Tree.
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski+renesas@gmail.com>
Signed-off-by: Chris Ball <cjb@laptop.org>

drivers/mmc/host/sh_mobile_sdhi.c

@@ -144,6 +144,7 @@ static int sh_mobile_sdhi_probe(struct platform_device *pdev)
 	struct tmio_mmc_host *host;
 	int irq, ret, i = 0;
 	bool multiplexed_isr = true;
+	struct tmio_mmc_dma *dma_priv;
 
 	priv = devm_kzalloc(&pdev->dev, sizeof(struct sh_mobile_sdhi), GFP_KERNEL);
 	if (priv == NULL) {
@@ -152,6 +153,7 @@ static int sh_mobile_sdhi_probe(struct platform_device *pdev)
 	}
 
 	mmc_data = &priv->mmc_data;
+	dma_priv = &priv->dma_priv;
 
 	if (p) {
 		if (p->init) {
@@ -184,8 +186,6 @@ static int sh_mobile_sdhi_probe(struct platform_device *pdev)
 			mmc_data->get_cd = sh_mobile_sdhi_get_cd;
 
 		if (p->dma_slave_tx > 0 && p->dma_slave_rx > 0) {
-			struct tmio_mmc_dma *dma_priv = &priv->dma_priv;
-
 			/*
 			 * Yes, we have to provide slave IDs twice to TMIO:
 			 * once as a filter parameter and once for channel
@@ -195,14 +195,14 @@ static int sh_mobile_sdhi_probe(struct platform_device *pdev)
 			dma_priv->chan_priv_rx = (void *)p->dma_slave_rx;
 			dma_priv->slave_id_tx = p->dma_slave_tx;
 			dma_priv->slave_id_rx = p->dma_slave_rx;
-
-			dma_priv->alignment_shift = 1; /* 2-byte alignment */
-			dma_priv->filter = shdma_chan_filter;
-
-			mmc_data->dma = dma_priv;
 		}
 	}
 
+	dma_priv->alignment_shift = 1; /* 2-byte alignment */
+	dma_priv->filter = shdma_chan_filter;
+
+	mmc_data->dma = dma_priv;
+
 	/*
 	 * All SDHI blocks support 2-byte and larger block sizes in 4-bit
 	 * bus width mode.

drivers/mmc/host/tmio_mmc_dma.c

@@ -264,7 +264,8 @@ static void tmio_mmc_tasklet_fn(unsigned long arg)
 void tmio_mmc_request_dma(struct tmio_mmc_host *host, struct tmio_mmc_data *pdata)
 {
 	/* We can only either use DMA for both Tx and Rx or not use it at all */
-	if (!pdata->dma)
+	if (!pdata->dma || (!host->pdev->dev.of_node &&
+		(!pdata->dma->chan_priv_tx || !pdata->dma->chan_priv_rx)))
 		return;
 
 	if (!host->chan_tx && !host->chan_rx) {
@@ -280,15 +281,17 @@ void tmio_mmc_request_dma(struct tmio_mmc_host *host, struct tmio_mmc_data *pdat
 		dma_cap_zero(mask);
 		dma_cap_set(DMA_SLAVE, mask);
 
-		host->chan_tx = dma_request_channel(mask, pdata->dma->filter,
-						    pdata->dma->chan_priv_tx);
+		host->chan_tx = dma_request_slave_channel_compat(mask,
+					pdata->dma->filter, pdata->dma->chan_priv_tx,
+					&host->pdev->dev, "tx");
 		dev_dbg(&host->pdev->dev, "%s: TX: got channel %p\n", __func__,
 			host->chan_tx);
 
 		if (!host->chan_tx)
 			return;
 
-		cfg.slave_id = pdata->dma->slave_id_tx;
+		if (pdata->dma->chan_priv_tx)
+			cfg.slave_id = pdata->dma->slave_id_tx;
 		cfg.direction = DMA_MEM_TO_DEV;
 		cfg.dst_addr = res->start + (CTL_SD_DATA_PORT << host->bus_shift);
 		cfg.src_addr = 0;
@@ -296,15 +299,17 @@ void tmio_mmc_request_dma(struct tmio_mmc_host *host, struct tmio_mmc_data *pdat
 		if (ret < 0)
 			goto ecfgtx;
 
-		host->chan_rx = dma_request_channel(mask, pdata->dma->filter,
-						    pdata->dma->chan_priv_rx);
+		host->chan_rx = dma_request_slave_channel_compat(mask,
+					pdata->dma->filter, pdata->dma->chan_priv_rx,
+					&host->pdev->dev, "rx");
 		dev_dbg(&host->pdev->dev, "%s: RX: got channel %p\n", __func__,
 			host->chan_rx);
 
 		if (!host->chan_rx)
 			goto ereqrx;
 
-		cfg.slave_id = pdata->dma->slave_id_rx;
+		if (pdata->dma->chan_priv_rx)
+			cfg.slave_id = pdata->dma->slave_id_rx;
 		cfg.direction = DMA_DEV_TO_MEM;
 		cfg.src_addr = cfg.dst_addr;
 		cfg.dst_addr = 0;