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authorHeiko Stübner <heiko@sntech.de>2013-06-25 14:55:42 +0200
committerLinus Walleij <linus.walleij@linaro.org>2013-06-25 15:33:57 +0200
commit70637a6dcaa6e4cb707d0d50a7ea448f13438786 (patch)
tree744b8bbb08ada890c1befa1d4c483282391d9291
parentad42fc6c84795d19972e7f7dee70fe74bec4c2d8 (diff)
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op-kernel-dev-70637a6dcaa6e4cb707d0d50a7ea448f13438786.tar.gz
pinctrl: more clarifications for generic pull configs
PULL_PIN_DEFAULT is meant for hardware completely hiding any pull settings from the driver, so that it's really only possible to turn the pull on or off, but it not being possible to determine any pull settings from software. Also the binding-documentation for the pull arguments did not match the changes to the expected values. Signed-off-by: Heiko Stuebner <heiko@sntech.de> Reviewed-by: James Hogan <james.hogan@imgtec.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
-rw-r--r--Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt5
-rw-r--r--include/linux/pinctrl/pinconf-generic.h5
2 files changed, 6 insertions, 4 deletions
diff --git a/Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt b/Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt
index 2d730e3..7498bdc 100644
--- a/Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt
+++ b/Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt
@@ -165,9 +165,8 @@ output-high - set the pin to output mode with high level
Arguments for parameters:
-- bias-pull-up, -down and -pin-default take as optional argument 0 to disable
- the pull, on hardware supporting it the pull strength in Ohm. bias-disable
- will also disable any active pull.
+- bias-pull-up, -down and -pin-default take as optional argument on hardware
+ supporting it the pull strength in Ohm. bias-disable will disable the pull.
- drive-strength takes as argument the target strength in mA.
diff --git a/include/linux/pinctrl/pinconf-generic.h b/include/linux/pinctrl/pinconf-generic.h
index 10ad996..48aa4ba 100644
--- a/include/linux/pinctrl/pinconf-generic.h
+++ b/include/linux/pinctrl/pinconf-generic.h
@@ -41,7 +41,10 @@
* impedance to GROUND). If the argument is != 0 pull-down is enabled,
* if it is 0, pull-down is total, i.e. the pin is connected to GROUND.
* @PIN_CONFIG_BIAS_PULL_PIN_DEFAULT: the pin will be pulled up or down based
- * on embedded knowledge of the controller, like current mux function.
+ * on embedded knowledge of the controller hardware, like current mux
+ * function. The pull direction and possibly strength too will normally
+ * be decided completely inside the hardware block and not be readable
+ * from the kernel side.
* If the argument is != 0 pull up/down is enabled, if it is 0, the
* configuration is ignored. The proper way to disable it is to use
* @PIN_CONFIG_BIAS_DISABLE.
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