Skip to content

Commit

Permalink
document: devicetree: bind pinconf with pin single
Browse files Browse the repository at this point in the history
Add comments with pinconf & gpio range in the document of
pinctrl-single.

Signed-off-by: Haojian Zhuang <haojian.zhuang@gmail.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
  • Loading branch information
Haojian Zhuang authored and Linus Walleij committed Mar 7, 2013
1 parent 9dddb4d commit 32378ab
Showing 1 changed file with 106 additions and 1 deletion.
107 changes: 106 additions & 1 deletion Documentation/devicetree/bindings/pinctrl/pinctrl-single.txt
Original file line number Diff line number Diff line change
@@ -1,7 +1,9 @@
One-register-per-pin type device tree based pinctrl driver

Required properties:
- compatible : "pinctrl-single"
- compatible : "pinctrl-single" or "pinconf-single".
"pinctrl-single" means that pinconf isn't supported.
"pinconf-single" means that generic pinconf is supported.

- reg : offset and length of the register set for the mux registers

Expand All @@ -14,9 +16,61 @@ Optional properties:
- pinctrl-single,function-off : function off mode for disabled state if
available and same for all registers; if not specified, disabling of
pin functions is ignored

- pinctrl-single,bit-per-mux : boolean to indicate that one register controls
more than one pin

- pinctrl-single,drive-strength : array of value that are used to configure
drive strength in the pinmux register. They're value of drive strength
current and drive strength mask.

/* drive strength current, mask */
pinctrl-single,power-source = <0x30 0xf0>;

- pinctrl-single,bias-pullup : array of value that are used to configure the
input bias pullup in the pinmux register.

/* input, enabled pullup bits, disabled pullup bits, mask */
pinctrl-single,bias-pullup = <0 1 0 1>;

- pinctrl-single,bias-pulldown : array of value that are used to configure the
input bias pulldown in the pinmux register.

/* input, enabled pulldown bits, disabled pulldown bits, mask */
pinctrl-single,bias-pulldown = <2 2 0 2>;

* Two bits to control input bias pullup and pulldown: User should use
pinctrl-single,bias-pullup & pinctrl-single,bias-pulldown. One bit means
pullup, and the other one bit means pulldown.
* Three bits to control input bias enable, pullup and pulldown. User should
use pinctrl-single,bias-pullup & pinctrl-single,bias-pulldown. Input bias
enable bit should be included in pullup or pulldown bits.
* Although driver could set PIN_CONFIG_BIAS_DISABLE, there's no property as
pinctrl-single,bias-disable. Because pinctrl single driver could implement
it by calling pulldown, pullup disabled.

- pinctrl-single,input-schmitt : array of value that are used to configure
input schmitt in the pinmux register. In some silicons, there're two input
schmitt value (rising-edge & falling-edge) in the pinmux register.

/* input schmitt value, mask */
pinctrl-single,input-schmitt = <0x30 0x70>;

- pinctrl-single,input-schmitt-enable : array of value that are used to
configure input schmitt enable or disable in the pinmux register.

/* input, enable bits, disable bits, mask */
pinctrl-single,input-schmitt-enable = <0x30 0x40 0 0x70>;

- pinctrl-single,gpio-range : list of value that are used to configure a GPIO
range. They're value of subnode phandle, pin base in pinctrl device, pin
number in this range, GPIO function value of this GPIO range.
The number of parameters is depend on #pinctrl-single,gpio-range-cells
property.

/* pin base, nr pins & gpio function */
pinctrl-single,gpio-range = <&range 0 3 0 &range 3 9 1>;

This driver assumes that there is only one register for each pin (unless the
pinctrl-single,bit-per-mux is set), and uses the common pinctrl bindings as
specified in the pinctrl-bindings.txt document in this directory.
Expand All @@ -42,6 +96,20 @@ Where 0xdc is the offset from the pinctrl register base address for the
device pinctrl register, 0x18 is the desired value, and 0xff is the sub mask to
be used when applying this change to the register.


Optional sub-node: In case some pins could be configured as GPIO in the pinmux
register, those pins could be defined as a GPIO range. This sub-node is required
by pinctrl-single,gpio-range property.

Required properties in sub-node:
- #pinctrl-single,gpio-range-cells : the number of parameters after phandle in
pinctrl-single,gpio-range property.

range: gpio-range {
#pinctrl-single,gpio-range-cells = <3>;
};


Example:

/* SoC common file */
Expand Down Expand Up @@ -76,6 +144,29 @@ control_devconf0: pinmux@48002274 {
pinctrl-single,function-mask = <0x5F>;
};

/* third controller instance for pins in gpio domain */
pmx_gpio: pinmux@d401e000 {
compatible = "pinconf-single";
reg = <0xd401e000 0x0330>;
#address-cells = <1>;
#size-cells = <1>;
ranges;

pinctrl-single,register-width = <32>;
pinctrl-single,function-mask = <7>;

/* sparse GPIO range could be supported */
pinctrl-single,gpio-range = <&range 0 3 0 &range 3 9 1
&range 12 1 0 &range 13 29 1
&range 43 1 0 &range 44 49 1
&range 94 1 1 &range 96 2 1>;

range: gpio-range {
#pinctrl-single,gpio-range-cells = <3>;
};
};


/* board specific .dts file */

&pmx_core {
Expand All @@ -96,6 +187,15 @@ control_devconf0: pinmux@48002274 {
>;
};

uart0_pins: pinmux_uart0_pins {
pinctrl-single,pins = <
0x208 0 /* UART0_RXD (IOCFG138) */
0x20c 0 /* UART0_TXD (IOCFG139) */
>;
pinctrl-single,bias-pulldown = <0 2 2>;
pinctrl-single,bias-pullup = <0 1 1>;
};

/* map uart2 pins */
uart2_pins: pinmux_uart2_pins {
pinctrl-single,pins = <
Expand All @@ -122,6 +222,11 @@ control_devconf0: pinmux@48002274 {

};

&uart1 {
pinctrl-names = "default";
pinctrl-0 = <&uart0_pins>;
};

&uart2 {
pinctrl-names = "default";
pinctrl-0 = <&uart2_pins>;
Expand Down

0 comments on commit 32378ab

Please sign in to comment.