mmc: sdhci: Auto-CMD23 support.

Enables Auto-CMD23 support where available (SDHCI 3.0 controllers)
Signed-off-by: Andrei Warkentin <andreiw@motorola.com>
Tested-by: Arindam Nath <arindam.nath@amd.com>
Signed-off-by: Chris Ball <cjb@laptop.org>

drivers/mmc/host/sdhci.c

@@ -857,7 +857,12 @@ static void sdhci_set_transfer_mode(struct sdhci_host *host,
 		 */
 		if (!host->mrq->sbc && (host->flags & SDHCI_AUTO_CMD12))
 			mode |= SDHCI_TRNS_AUTO_CMD12;
+		else if (host->mrq->sbc && (host->flags & SDHCI_AUTO_CMD23)) {
+			mode |= SDHCI_TRNS_AUTO_CMD23;
+			sdhci_writel(host, host->mrq->sbc->arg, SDHCI_ARGUMENT2);
+		}
 	}
+
 	if (data->flags & MMC_DATA_READ)
 		mode |= SDHCI_TRNS_READ;
 	if (host->flags & SDHCI_REQ_USE_DMA)
@@ -1252,7 +1257,7 @@ static void sdhci_request(struct mmc_host *mmc, struct mmc_request *mrq)
 			host->mrq = mrq;
 		}
 
-		if (mrq->sbc)
+		if (mrq->sbc && !(host->flags & SDHCI_AUTO_CMD23))
 			sdhci_send_command(host, mrq->sbc);
 		else
 			sdhci_send_command(host, mrq->cmd);
@@ -2488,6 +2493,16 @@ int sdhci_add_host(struct sdhci_host *host)
 	if (host->quirks & SDHCI_QUIRK_MULTIBLOCK_READ_ACMD12)
 		host->flags |= SDHCI_AUTO_CMD12;
 
+	/* Auto-CMD23 stuff only works in ADMA or PIO. */
+	if ((host->version == SDHCI_SPEC_300) &&
+	    ((host->flags & SDHCI_USE_ADMA) ||
+	     !(host->flags & SDHCI_REQ_USE_DMA))) {
+		host->flags |= SDHCI_AUTO_CMD23;
+		DBG("%s: Auto-CMD23 available\n", mmc_hostname(mmc));
+	} else {
+		DBG("%s: Auto-CMD23 unavailable\n", mmc_hostname(mmc));
+	}
+
 	/*
 	 * A controller may support 8-bit width, but the board itself
 	 * might not have the pins brought out.  Boards that support

drivers/mmc/host/sdhci.h

@@ -25,6 +25,7 @@
  */
 
 #define SDHCI_DMA_ADDRESS	0x00
+#define SDHCI_ARGUMENT2		SDHCI_DMA_ADDRESS
 
 #define SDHCI_BLOCK_SIZE	0x04
 #define  SDHCI_MAKE_BLKSZ(dma, blksz) (((dma & 0x7) << 12) | (blksz & 0xFFF))
@@ -37,6 +38,7 @@
 #define  SDHCI_TRNS_DMA		0x01
 #define  SDHCI_TRNS_BLK_CNT_EN	0x02
 #define  SDHCI_TRNS_AUTO_CMD12	0x04
+#define  SDHCI_TRNS_AUTO_CMD23	0x08
 #define  SDHCI_TRNS_READ	0x10
 #define  SDHCI_TRNS_MULTI	0x20
 

include/linux/mmc/sdhci.h

@@ -114,6 +114,7 @@ struct sdhci_host {
 #define SDHCI_SDR50_NEEDS_TUNING (1<<4)	/* SDR50 needs tuning */
 #define SDHCI_NEEDS_RETUNING	(1<<5)	/* Host needs retuning */
 #define SDHCI_AUTO_CMD12	(1<<6)	/* Auto CMD12 support */
+#define SDHCI_AUTO_CMD23	(1<<7)	/* Auto CMD23 support */
 
 	unsigned int version;	/* SDHCI spec. version */