[v2] mmc: mmci: Allow MMCI to request channels with information acquired from DT

Commit Message

Lee Jones April 24, 2013, 3:55 p.m. UTC

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 <[e-mail]>
Cc: Chris Ball <[e-mail]>
Cc: [e-mail]
Signed-off-by: Lee Jones <[e-mail]>

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Comments

Linus Walleij May 23, 2013, 7 p.m. UTC | #1

On Wed, Apr 24, 2013 at 5:55 PM, Lee Jones <[e-mail]> wrote:

> 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 <[e-mail]>
> Cc: Chris Ball <[e-mail]>
> Cc: [e-mail]
> Signed-off-by: Lee Jones <[e-mail]>

I've now tested this v2 version with device tree on Nomadik and
U300 and it works like a charm.
Tested-by: Linus Walleij <[e-mail]>

Yours,
Linus Walleij
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Patch

diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
index 372e921..45dda46 100644
--- a/drivers/mmc/host/mmci.c
+++ b/drivers/mmc/host/mmci.c
@@ -304,10 +304,8 @@  static void mmci_dma_setup(struct mmci_host *host)
 	const char *rxname, *txname;
 	dma_cap_mask_t mask;
 
-	if (!plat || !plat->dma_filter) {
-		dev_info(mmc_dev(host->mmc), "no DMA platform data\n");
-		return;
-	}
+	host->dma_rx_channel = dma_request_slave_channel(mmc_dev(host->mmc), "rx");
+	host->dma_tx_channel = dma_request_slave_channel(mmc_dev(host->mmc), "tx");
 
 	/* initialize pre request cookie */
 	host->next_data.cookie = 1;
@@ -316,30 +314,33 @@  static void mmci_dma_setup(struct mmci_host *host)
 	dma_cap_zero(mask);
 	dma_cap_set(DMA_SLAVE, mask);
 
-	/*
-	 * If only an RX channel is specified, the driver will
-	 * 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,
+	if (plat && plat->dma_filter) {
+		if (!host->dma_rx_channel && plat->dma_rx_param) {
+			host->dma_rx_channel = dma_request_channel(mask,
 							   plat->dma_filter,
 							   plat->dma_rx_param);
-		/* E.g if no DMA hardware is present */
-		if (!host->dma_rx_channel)
-			dev_err(mmc_dev(host->mmc), "no RX DMA channel\n");
-	}
+			/* 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,
+		if (!host->dma_tx_channel && plat->dma_tx_param) {
+			host->dma_tx_channel = dma_request_channel(mask,
 							   plat->dma_filter,
 							   plat->dma_tx_param);
-		if (!host->dma_tx_channel)
-			dev_warn(mmc_dev(host->mmc), "no TX DMA channel\n");
-	} else {
-		host->dma_tx_channel = host->dma_rx_channel;
+			if (!host->dma_tx_channel)
+				dev_warn(mmc_dev(host->mmc), "no TX DMA channel\n");
+		}
 	}
 
+	/*
+	 * If only an RX channel is specified, the driver will
+	 * attempt to use it bidirectionally, however if it is
+	 * is specified but cannot be located, DMA will be disabled.
+	 */
+	if (host->dma_rx_channel && !host->dma_tx_channel)
+		host->dma_tx_channel = host->dma_rx_channel;
+
 	if (host->dma_rx_channel)
 		rxname = dma_chan_name(host->dma_rx_channel);
 	else