Kconfig: Migrate BOUNCE_BUFFER

The bounce buffer is used by a few drivers (most of the MMC drivers)
to overcome limitations in their respective DMA implementation.

This moves the configuration to Kconfig and makes it user-selectable
(even though it will be a required feature to make those drivers
work): the expected usage is for drivers depending on this to 'select'
it unconditionally from their respective Kconfig (see follow-up
patches).

This commit includes a full migration using moveconfig.py to ensure
that each commit compiles.  To ensure bisectability we update
dependencies of various drivers to now select BOUNCE_BUFFER when needed.

[trini: Squash all patches to ensure bisectability]
Signed-off-by: Tom Rini <trini@konsulko.com>
Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Reviewed-by: Otavio Salvador <otavio@ossystems.com.br> [dw_mmc portion]
Reviewed-by: Fabio Estevam <festevam@gmail.com> [mxsmmc portion]
Reviewed-by: Simon Glass <sjg@chromium.org> [tegra portion]

1 files changed, 11 insertions, 0 deletions

diff --git a/common/Kconfig b/common/Kconfig
index 2c017df4087..8f9d2959ba5 100644
--- a/common/Kconfig
+++ b/common/Kconfig
@@ -645,6 +645,17 @@ config DISPLAY_BOARDINFO_LATE
 	  the relocation phase. The board function checkboard() is called to do
 	  this.
 
+config BOUNCE_BUFFER
+	bool "Include bounce buffer API"
+	help
+	  Some peripherals support DMA from a subset of physically
+	  addressable memory only.  To support such peripherals, the
+	  bounce buffer API uses a temporary buffer: it copies data
+	  to/from DMA regions while managing cache operations.
+
+	  A second possible use of bounce buffers is their ability to
+	  provide aligned buffers for DMA operations.
+
 menu "Start-up hooks"
 
 config ARCH_EARLY_INIT_R