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>

2 files changed, 18 insertions, 1 deletions

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index b9ed66307ac..f845fd6a64a 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/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
diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
index 2c3fbc5a4c0..745c42fa41e 100644
--- a/drivers/mmc/host/sdhci.h
+++ b/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