[PATCH] mmc: mmci: Allow MMCI to request channels with information acquired from DT

[Lee Jones]

Currently, if DMA information isn't passed from platform data, then DMA
will not be used. This patch allows DMA information obtained though Device
Tree to be used as well.

Cc: Russell King <linux at arm.linux.org.uk>
Cc: Chris Ball <cjb at laptop.org>
Cc: linux-mmc at vger.kernel.org
Signed-off-by: Lee Jones <lee.jones at linaro.org>
---
 drivers/mmc/host/mmci.c |   43 +++++++++++++++++++++++++++++++------------
 1 file changed, 31 insertions(+), 12 deletions(-)

diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
index 372e921..42e8fec 100644
--- a/drivers/mmc/host/mmci.c
+++ b/drivers/mmc/host/mmci.c
@@ -298,15 +298,32 @@ static void mmci_init_sg(struct mmci_host *host, struct mmc_data *data)
  * no custom DMA interfaces are supported.
  */
 #ifdef CONFIG_DMA_ENGINE
-static void mmci_dma_setup(struct mmci_host *host)
+static void mmci_dma_setup(struct amba_device *dev,
+			   struct mmci_host *host)
 {
+	struct device_node *np = dev->dev.of_node;
 	struct mmci_platform_data *plat = host->plat;
 	const char *rxname, *txname;
 	dma_cap_mask_t mask;
+	const char *chan_name;
+	int count, i;
+	bool do_tx = false, do_rx = false;
 
 	if (!plat || !plat->dma_filter) {
-		dev_info(mmc_dev(host->mmc), "no DMA platform data\n");
-		return;
+		if (np) {
+			count = of_property_count_strings(np, "dma-names");
+			for (i = 0; i < count; i++) {
+				of_property_read_string_index(np, "dma-names",
+							      i, &chan_name);
+				if (strcmp(chan_name, "tx"))
+					do_tx = true;
+				else if (strcmp(chan_name, "rx"))
+					do_rx = true;
+			}
+		} else {
+			dev_info(mmc_dev(host->mmc), "no DMA platform data\n");
+			return;
+		}
 	}
 
 	/* initialize pre request cookie */
@@ -321,19 +338,21 @@ static void mmci_dma_setup(struct mmci_host *host)
 	 * attempt to use it bidirectionally, however if it is
 	 * is specified but cannot be located, DMA will be disabled.
 	 */
-	if (plat->dma_rx_param) {
-		host->dma_rx_channel = dma_request_channel(mask,
-							   plat->dma_filter,
-							   plat->dma_rx_param);
+	if (plat->dma_rx_param || do_rx) {
+		host->dma_rx_channel = dma_request_slave_channel_compat(mask,
+					(plat) ? plat->dma_filter : NULL,
+					(plat) ? plat->dma_rx_param : NULL,
+					&dev->dev, "rx");
 		/* E.g if no DMA hardware is present */
 		if (!host->dma_rx_channel)
 			dev_err(mmc_dev(host->mmc), "no RX DMA channel\n");
 	}
 
-	if (plat->dma_tx_param) {
-		host->dma_tx_channel = dma_request_channel(mask,
-							   plat->dma_filter,
-							   plat->dma_tx_param);
+	if (plat->dma_tx_param || do_tx) {
+		host->dma_tx_channel = dma_request_slave_channel_compat(mask,
+					(plat) ? plat->dma_filter : NULL,
+					(plat) ? plat->dma_tx_param : NULL,
+					&dev->dev, "tx");
 		if (!host->dma_tx_channel)
 			dev_warn(mmc_dev(host->mmc), "no TX DMA channel\n");
 	} else {
@@ -1538,7 +1557,7 @@ static int mmci_probe(struct amba_device *dev,
 		 amba_rev(dev), (unsigned long long)dev->res.start,
 		 dev->irq[0], dev->irq[1]);
 
-	mmci_dma_setup(host);
+	mmci_dma_setup(dev, host);
 
 	pm_runtime_set_autosuspend_delay(&dev->dev, 50);
 	pm_runtime_use_autosuspend(&dev->dev);
-- 
1.7.10.4