mmc: wmt-sdmmc: Fix settting BM_EIGHTBIT_MODE bit in wmt_mci_set_ios()

For MMC_BUS_WIDTH_8 case, current code missed setting BM_EIGHTBIT_MODE bit. Also has a small refactor to make the code looks better in readability.

So the bit settings witch below logic:

SDMMC_BUSMODE register:
Set EIGHTBIT_MODE bit for 8 bit mode, Set FOURBIT_MODE bit for 4 bit mode. Clear both EIGHTBIT_MODE and FOURBIT_MODE bits for 1 bit mode.

SDMMC_EXTCTRL register:
Set EXT_EIGHTBIT bit for 8 bit mode, Clear EXT_EIGHTBIT bit for 1/4 bit mode.

Add define for EXT_EIGHTBIT to avoid using magic number. BM_ONEBIT_MASK is no longer used, thus remove it.

This patch is untested due to lack of platform with 8-bit hardware. However since the code is there, it's good to make the code match the document.

Signed-off-by Axel Lin <[email protected]>

---
This patch was sent on:
http://www.spinics.net/lists/linux-mmc/msg22926.html
The document (wm8505 sdmmc controller suppliment.pdf) is available at:
https://groups.google.com/group/vt8500-wm8505-linux-kernel/attach/ac3d5037e860a34/wm8505%20sdmmc%20controller%20suppliment.pdf?part=4&authuser=1

Regards,
Axel

 drivers/mmc/host/wmt-sdmmc.c | 31 +++++++++++++++----------------
 1 file changed, 15 insertions(+), 16 deletions(-)

drivers/mmc/host/wmt-sdmmc.c +15 -17

index 8a48a50..6ed18f8 100644
@@ -72,7 +72,6 @@
 #define BM_SPI_CS                      0x20
 #define BM_SD_POWER                    0x40
 #define BM_SOFT_RESET                  0x80
-#define BM_ONEBIT_MASK                 0xFD
 
 /* SDMMC_BLKLEN bit fields */
 #define BLKL_CRCERR_ABORT              0x0800

@@ -120,6 +119,8 @@
 #define STS2_DATARSP_BUSY              0x20
 #define STS2_DIS_FORCECLK              0x80
 
+/* SDMMC_EXTCTRL bit fields */
+#define EXT_EIGHTBIT                   0x04
 
 /* MMC/SD DMA Controller Registers */
 #define SDDMA_GCR                      0x100

@@ -672,7 +673,7 @@ static void wmt_mci_request(struct mmc_host *mmc, struct mmc_request *req)
 static void wmt_mci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
 {
        struct wmt_mci_priv *priv;
-       u32 reg_tmp;
+       u32 busmode, extctrl;
 
        priv = mmc_priv(mmc);
 

@@ -687,28 +688,26 @@ static void wmt_mci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
        if (ios->clock != 0)
                clk_set_rate(priv->clk_sdmmc, ios->clock);
 
+       busmode = readb(priv->sdmmc_base + SDMMC_BUSMODE);
+       extctrl = readb(priv->sdmmc_base + SDMMC_EXTCTRL);
+
+       busmode &= ~(BM_EIGHTBIT_MODE | BM_FOURBIT_MODE);
+       extctrl &= ~EXT_EIGHTBIT;
+
        switch (ios->bus_width) {
        case MMC_BUS_WIDTH_8:
-               reg_tmp = readb(priv->sdmmc_base + SDMMC_EXTCTRL);
-               writeb(reg_tmp | 0x04, priv->sdmmc_base + SDMMC_EXTCTRL);
+               busmode |= BM_EIGHTBIT_MODE;
+               extctrl |= EXT_EIGHTBIT;
                break;
        case MMC_BUS_WIDTH_4:
-               reg_tmp = readb(priv->sdmmc_base + SDMMC_BUSMODE);
-               writeb(reg_tmp | BM_FOURBIT_MODE, priv->sdmmc_base +
-                      SDMMC_BUSMODE);
-
-               reg_tmp = readb(priv->sdmmc_base + SDMMC_EXTCTRL);
-               writeb(reg_tmp & 0xFB, priv->sdmmc_base + SDMMC_EXTCTRL);
+               busmode |= BM_FOURBIT_MODE;
                break;
        case MMC_BUS_WIDTH_1:
-               reg_tmp = readb(priv->sdmmc_base + SDMMC_BUSMODE);
-               writeb(reg_tmp & BM_ONEBIT_MASK, priv->sdmmc_base +
-                      SDMMC_BUSMODE);
-
-               reg_tmp = readb(priv->sdmmc_base + SDMMC_EXTCTRL);
-               writeb(reg_tmp & 0xFB, priv->sdmmc_base + SDMMC_EXTCTRL);
                break;
        }
+
+       writeb(busmode, priv->sdmmc_base + SDMMC_BUSMODE);
+       writeb(extctrl, priv->sdmmc_base + SDMMC_EXTCTRL);
 }
 
 static int wmt_mci_get_ro(struct mmc_host *mmc)
--

1.8.1.2