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authorTakashi Iwai <tiwai@suse.de>2016-05-27 17:16:53 +0200
committerTakashi Iwai <tiwai@suse.de>2016-05-27 17:16:53 +0200
commiteb4606e64a7d548f5d60a9583baa8104890b2c6e (patch)
tree2dc8e587fc79c207dab2fb74830963cc84dcf801 /Documentation/devicetree/bindings/regmap/regmap.txt
parentALSA: hda - Fix headset mic detection problem for one Dell machine (diff)
parentMerge remote-tracking branch 'asoc/topic/wm8962' into asoc-next (diff)
downloadwireguard-linux-eb4606e64a7d548f5d60a9583baa8104890b2c6e.tar.xz
wireguard-linux-eb4606e64a7d548f5d60a9583baa8104890b2c6e.zip
Merge tag 'asoc-v4.7-2' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound into for-linus
ASoC: Updates for v4.7 part 2 Really sorry about this late pull request. It looks like at the time I sent my pull request for v4.7 there was some conflict or other issue which caused my script to stop merging the ASoC branches at some point after the HDMI changes. It's all specific driver updates, including: - New drivers for MAX98371 and TAS5720. - SPI support for TLV320AIC32x4. - TDM support for STI Uniperf IPs. This code should all have been in -next prior to the merge window apart from some fixes, it dropped out on the 18th.
Diffstat (limited to 'Documentation/devicetree/bindings/regmap/regmap.txt')
-rw-r--r--Documentation/devicetree/bindings/regmap/regmap.txt59
1 files changed, 19 insertions, 40 deletions
diff --git a/Documentation/devicetree/bindings/regmap/regmap.txt b/Documentation/devicetree/bindings/regmap/regmap.txt
index e98a9652ccc8..0127be360fe8 100644
--- a/Documentation/devicetree/bindings/regmap/regmap.txt
+++ b/Documentation/devicetree/bindings/regmap/regmap.txt
@@ -1,50 +1,29 @@
-Device-Tree binding for regmap
-
-The endianness mode of CPU & Device scenarios:
-Index Device Endianness properties
----------------------------------------------------
-1 BE 'big-endian'
-2 LE 'little-endian'
-3 Native 'native-endian'
-
-For one device driver, which will run in different scenarios above
-on different SoCs using the devicetree, we need one way to simplify
-this.
+Devicetree binding for regmap
Optional properties:
-- {big,little,native}-endian: these are boolean properties, if absent
- then the implementation will choose a default based on the device
- being controlled. These properties are for register values and all
- the buffers only. Native endian means that the CPU and device have
- the same endianness.
-Examples:
-Scenario 1 : CPU in LE mode & device in LE mode.
-dev: dev@40031000 {
- compatible = "name";
- reg = <0x40031000 0x1000>;
- ...
-};
+ little-endian,
+ big-endian,
+ native-endian: See common-properties.txt for a definition
-Scenario 2 : CPU in LE mode & device in BE mode.
-dev: dev@40031000 {
- compatible = "name";
- reg = <0x40031000 0x1000>;
- ...
- big-endian;
-};
+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.
-Scenario 3 : CPU in BE mode & device in BE mode.
-dev: dev@40031000 {
- compatible = "name";
- reg = <0x40031000 0x1000>;
- ...
-};
+On SoCs that can be operated in both big-endian and little-endian
+modes, with a single hardware switch controlling both the endianess
+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.
-Scenario 4 : CPU in BE mode & device in LE mode.
+Examples:
+Scenario 1 : a register set in big-endian mode.
dev: dev@40031000 {
- compatible = "name";
+ compatible = "syscon";
reg = <0x40031000 0x1000>;
+ big-endian;
...
- little-endian;
};