sdhci-of: reorganize driver to support additional hardware

This patch breaks down sdhci-of into a core portion and a eSDHC portion,
clearing the path to easily support additional hardware using the same OF
driver.

Signed-off-by: Albert Herranz <albert_herranz@yahoo.es>
Cc: <linux-mmc@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 23 insertions, 3 deletions

diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
index 9d405b181781..d9234648199a 100644
--- a/drivers/mmc/host/Kconfig
+++ b/drivers/mmc/host/Kconfig
@@ -44,6 +44,19 @@ config MMC_SDHCI_IO_ACCESSORS
           This is silent Kconfig symbol that is selected by the drivers that
           need to overwrite SDHCI IO memory accessors.
 
+config MMC_SDHCI_BIG_ENDIAN_32BIT_BYTE_SWAPPER
+        bool
+        select MMC_SDHCI_IO_ACCESSORS
+        help
+          This option is selected by drivers running on big endian hosts
+          and performing I/O to a SDHCI controller through a bus that
+          implements a hardware byte swapper using a 32-bit datum.
+          This endian mapping mode is called "data invariance" and
+          has the effect of scrambling the addresses and formats of data
+          accessed in sizes other than the datum size.
+
+          This is the case for the Freescale eSDHC.
+
 config MMC_SDHCI_PCI
         tristate "SDHCI support on PCI bus"
         depends on MMC_SDHCI && PCI
@@ -75,11 +88,18 @@ config MMC_RICOH_MMC
 config MMC_SDHCI_OF
         tristate "SDHCI support on OpenFirmware platforms"
         depends on MMC_SDHCI && PPC_OF
-        select MMC_SDHCI_IO_ACCESSORS
         help
           This selects the OF support for Secure Digital Host Controller
-          Interfaces. So far, only the Freescale eSDHC controller is known
-          to exist on OF platforms.
+          Interfaces.
+
+          If unsure, say N.
+
+config MMC_SDHCI_OF_ESDHC
+        bool "SDHCI OF support for the Freescale eSDHC controller"
+        depends on MMC_SDHCI_OF
+        select MMC_SDHCI_BIG_ENDIAN_32BIT_BYTE_SWAPPER
+        help
+          This selects the Freescale eSDHC controller support.
 
           If unsure, say N.