mmc: sdhci-esdhc-imx: add SDHCI_TRANSFER_MODE read function

Used to read out the correct value of SDHCI_TRANSFER_MODE register
for upper layer.

Signed-off-by: Dong Aisheng <b29396@freescale.com>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Chris Ball <cjb@laptop.org>

1 files changed, 16 insertions, 0 deletions

diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c b/drivers/mmc/host/sdhci-esdhc-imx.c
index 461a4c3f4ef7..2be77e0dcc4e 100644
--- a/drivers/mmc/host/sdhci-esdhc-imx.c
+++ b/drivers/mmc/host/sdhci-esdhc-imx.c
@@ -385,6 +385,22 @@ static u16 esdhc_readw_le(struct sdhci_host *host, int reg)
                 return ret;
         }
 
+        if (unlikely(reg == SDHCI_TRANSFER_MODE)) {
+                if (esdhc_is_usdhc(imx_data)) {
+                        u32 m = readl(host->ioaddr + ESDHC_MIX_CTRL);
+                        ret = m & ESDHC_MIX_CTRL_SDHCI_MASK;
+                        /* Swap AC23 bit */
+                        if (m & ESDHC_MIX_CTRL_AC23EN) {
+                                ret &= ~ESDHC_MIX_CTRL_AC23EN;
+                                ret |= SDHCI_TRNS_AUTO_CMD23;
+                        }
+                } else {
+                        ret = readw(host->ioaddr + SDHCI_TRANSFER_MODE);
+                }
+
+                return ret;
+        }
+
         return readw(host->ioaddr + reg);
 }