[U-Boot] [PATCH 1/6] Kconfig: Migrate BOUNCE_BUFFER

[Philipp Tomsich]

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.

Signed-off-by: Philipp Tomsich <philipp.tomsich at theobroma-systems.com>

---

 common/Kconfig               | 8 ++++++++
 scripts/config_whitelist.txt | 1 -
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/common/Kconfig b/common/Kconfig
index 57bd16d..f45e066 100644
--- a/common/Kconfig
+++ b/common/Kconfig
@@ -645,6 +645,14 @@ 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.
+
 menu "Start-up hooks"
 
 config ARCH_EARLY_INIT_R
diff --git a/scripts/config_whitelist.txt b/scripts/config_whitelist.txt
index b3f525f..2151d65 100644
--- a/scripts/config_whitelist.txt
+++ b/scripts/config_whitelist.txt
@@ -169,7 +169,6 @@ CONFIG_BOOT_OS_NET
 CONFIG_BOOT_PARAMS_ADDR
 CONFIG_BOOT_RETRY_MIN
 CONFIG_BOOT_RETRY_TIME
-CONFIG_BOUNCE_BUFFER
 CONFIG_BPTR_VIRT_ADDR
 CONFIG_BS_ADDR_DEVICE
 CONFIG_BS_ADDR_RAM
-- 
2.1.4