mmc: sdhci: 8-bit bus width changes

We now:
 * check for a v3 controller before setting 8-bit bus width
 * offer a callback for platform code to switch to 8-bit mode, which
   allows non-v3 controllers to support it
 * rely on mmc->caps |= MMC_CAP_8_BIT_DATA; in platform code to specify
   that the board designers have indeed brought out all the pins for
   8-bit to the slot.

We were previously relying only on whether the *controller* supported
8-bit, which doesn't tell us anything about the pin configuration in
the board design.

This fixes the MMC card regression reported by Maxim Levitsky here:
   http://thread.gmane.org/gmane.linux.kernel.mmc/4336
by no longer assuming that 8-bit works by default.

Signed-off-by: Philip Rakity <prakity@marvell.com>
Tested-by: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
index d52a716..e42d7f0 100644
--- a/drivers/mmc/host/sdhci.h
+++ b/drivers/mmc/host/sdhci.h
@@ -76,7 +76,7 @@
 #define   SDHCI_CTRL_ADMA1	0x08
 #define   SDHCI_CTRL_ADMA32	0x10
 #define   SDHCI_CTRL_ADMA64	0x18
-#define  SDHCI_CTRL_8BITBUS	0x20
+#define   SDHCI_CTRL_8BITBUS	0x20
 
 #define SDHCI_POWER_CONTROL	0x29
 #define  SDHCI_POWER_ON		0x01
@@ -155,6 +155,7 @@
 #define  SDHCI_CLOCK_BASE_SHIFT	8
 #define  SDHCI_MAX_BLOCK_MASK	0x00030000
 #define  SDHCI_MAX_BLOCK_SHIFT  16
+#define  SDHCI_CAN_DO_8BIT	0x00040000
 #define  SDHCI_CAN_DO_ADMA2	0x00080000
 #define  SDHCI_CAN_DO_ADMA1	0x00100000
 #define  SDHCI_CAN_DO_HISPD	0x00200000
@@ -215,6 +216,8 @@
 	unsigned int	(*get_max_clock)(struct sdhci_host *host);
 	unsigned int	(*get_min_clock)(struct sdhci_host *host);
 	unsigned int	(*get_timeout_clock)(struct sdhci_host *host);
+	int		(*platform_8bit_width)(struct sdhci_host *host,
+					       int width);
 	void (*platform_send_init_74_clocks)(struct sdhci_host *host,
 					     u8 power_mode);
 	unsigned int    (*get_ro)(struct sdhci_host *host);