ARM: 9480/1: entry: expand comment in __switch_tografted

As per discussion between the developers in the mail thread
linked, expand the comment in __switch_to so that readers
of the code understand what is going on.

Suggested-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Linus Walleij <linusw@kernel.org>>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

1 files changed, 29 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/regmap/regmap.txt b/Documentation/devicetree/bindings/regmap/regmap.txt
new file mode 100644
index 000000000..873096be0
--- /dev/null
+++ b/Documentation/devicetree/bindings/regmap/regmap.txt
@@ -0,0 +1,29 @@
+Devicetree binding for regmap
+
+Optional properties:
+
+   little-endian,
+   big-endian,
+   native-endian:	See common-properties.txt for a definition
+
+Note:
+Regmap defaults to little-endian register access on MMIO based
+devices, this is by far the most common setting. On CPU
+architectures that typically run big-endian operating systems
+(e.g. PowerPC), registers can be defined as big-endian and must
+be marked that way in the devicetree.
+
+On SoCs that can be operated in both big-endian and little-endian
+modes, with a single hardware switch controlling both the endianness
+of the CPU and a byteswap for MMIO registers (e.g. many Broadcom MIPS
+chips), "native-endian" is used to allow using the same device tree
+blob in both cases.
+
+Examples:
+Scenario 1 : a register set in big-endian mode.
+dev: dev@40031000 {
+	      compatible = "syscon";
+	      reg = <0x40031000 0x1000>;
+	      big-endian;
+	      ...
+};