[PATCH v3 4/4] Documentation: add LP3943 DT bindings and document

Milo Kim
2013-09-12T01:35:16Z

Bindings for LP3943 MFD, GPIO and PWM controller are added.
And LP3943 driver document is added also.

Cc: devicetree@vger.kernel.org
Cc: Lee Jones <lee.jones@linaro.org>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Samuel Ortiz <sameo@linux.intel.com>
Cc: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Milo Kim <milo.kim@ti.com>
---
Documentation/00-INDEX | 2 +
.../devicetree/bindings/gpio/gpio-lp3943.txt | 37 ++++++++++++
Documentation/devicetree/bindings/mfd/lp3943.txt | 33 +++++++++++
.../devicetree/bindings/pwm/pwm-lp3943.txt | 58 ++++++++++++++++++
Documentation/lp3943.txt | 62 ++++++++++++++++++++
5 files changed, 192 insertions(+)
create mode 100644 Documentation/devicetree/bindings/gpio/gpio-lp3943.txt
create mode 100644 Documentation/devicetree/bindings/mfd/lp3943.txt
create mode 100644 Documentation/devicetree/bindings/pwm/pwm-lp3943.txt
create mode 100644 Documentation/lp3943.txt

diff --git a/Documentation/00-INDEX b/Documentation/00-INDEX
index 0c4cc68..5dd921f 100644
--- a/Documentation/00-INDEX
+++ b/Documentation/00-INDEX
@@ -285,6 +285,8 @@ logo.gif
- full colour GIF image of Linux logo (penguin - Tux).
logo.txt
- info on creator of above logo & site to get additional images from.
+lp3943.txt
+ - info on LP3943 MFD driver structure.
m68k/
- directory with info about Linux on Motorola 68k architecture.
magic-number.txt
diff --git a/Documentation/devicetree/bindings/gpio/gpio-lp3943.txt b/Documentation/devicetree/bindings/gpio/gpio-lp3943.txt
new file mode 100644
index 0000000..80fcb7d
--- /dev/null
+++ b/Documentation/devicetree/bindings/gpio/gpio-lp3943.txt
@@ -0,0 +1,37 @@
+TI/National Semiconductor LP3943 GPIO controller
+
+Required properties:
+ - compatible: "ti,lp3943-gpio"
+ - gpio-controller: Marks the device node as a GPIO controller.
+ - #gpio-cells: Should be 2. See gpio.txt in this directory for a
+ description of the cells format.
+
+Example:
+Simple LED controls with LP3943 GPIO controller
+
+&i2c4 {
+ lp3943@60 {
+ compatible = "ti,lp3943";
+ reg = <0x60>;
+
+ gpioex: gpio {
+ compatible = "ti,lp3943-gpio";
+ gpio-controller;
+ #gpio-cells = <2>;
+ };
+ };
+};
+
+leds {
+ compatible = "gpio-leds";
+ indicator1 {
+ label = "indi1";
+ gpios = <&gpioex 9 GPIO_ACTIVE_LOW>;
+ };
+
+ indicator2 {
+ label = "indi2";
+ gpios = <&gpioex 10 GPIO_ACTIVE_LOW>;
+ default-state = "off";
+ };
+};
diff --git a/Documentation/devicetree/bindings/mfd/lp3943.txt b/Documentation/devicetree/bindings/mfd/lp3943.txt
new file mode 100644
index 0000000..e8591d6
--- /dev/null
+++ b/Documentation/devicetree/bindings/mfd/lp3943.txt
@@ -0,0 +1,33 @@
+TI/National Semiconductor LP3943 MFD driver
+
+Required properties:
+ - compatible: "ti,lp3943"
+ - reg: I2C slave address. From 0x60 to 0x67.
+
+LP3943 consists of two sub-devices, lp3943-gpio and lp3943-pwm.
+
+For the LP3943 GPIO properties please refer to:
+Documentation/devicetree/bindings/gpio/gpio-lp3943.txt
+
+For the LP3943 PWM properties please refer to:
+Documentation/devicetree/bindings/pwm/pwm-lp3943.txt
+
+Example:
+
+lp3943@60 {
+ compatible = "ti,lp3943";
+ reg = <0x60>;
+
+ gpioex: gpio {
+ compatible = "ti,lp3943-gpio";
+ gpio-controller;
+ #gpio-cells = <2>;
+ };
+
+ pwm3943: pwm {
+ compatible = "ti,lp3943-pwm";
+ #pwm-cells = <2>;
+ ti,pwm0 = <8 9 10>;
+ ti,pwm1 = <15>;
+ };
+};
diff --git a/Documentation/devicetree/bindings/pwm/pwm-lp3943.txt b/Documentation/devicetree/bindings/pwm/pwm-lp3943.txt
new file mode 100644
index 0000000..7bd9d3b
--- /dev/null
+++ b/Documentation/devicetree/bindings/pwm/pwm-lp3943.txt
@@ -0,0 +1,58 @@
+TI/National Semiconductor LP3943 PWM controller
+
+Required properties:
+ - compatible: "ti,lp3943-pwm"
+ - #pwm-cells: Should be 2. See pwm.txt in this directory for a
+ description of the cells format.
+ Note that this hardware limits the period length to the
+ range 6250~1600000.
+ - ti,pwm0 or ti,pwm1: Output pin number(s) for PWM channel 0 or 1.
+ 0 = output 0
+ 1 = output 1
+ .
+ .
+ 15 = output 15
+
+Example:
+PWM 0 is for RGB LED brightness control
+PWM 1 is for brightness control of LP8557 backlight device
+
+&i2c3 {
+ lp3943@60 {
+ compatible = "ti,lp3943";
+ reg = <0x60>;
+
+ /*
+ * PWM 0 : output 8, 9 and 10
+ * PWM 1 : output 15
+ */
+ pwm3943: pwm {
+ compatible = "ti,lp3943-pwm";
+ #pwm-cells = <2>;
+ ti,pwm0 = <8 9 10>;
+ ti,pwm1 = <15>;
+ };
+ };
+
+};
+
+/* LEDs control with PWM 0 of LP3943 */
+pwmleds {
+ compatible = "pwm-leds";
+ rgb {
+ label = "indi::rgb";
+ pwms = <&pwm3943 0 10000>;
+ max-brightness = <255>;
+ };
+};
+
+&i2c4 {
+ /* Backlight control with PWM 1 of LP3943 */
+ backlight@2c {
+ compatible = "ti,lp8557";
+ reg = <0x2c>;
+
+ pwms = <&pwm3943 1 10000>;
+ pwm-names = "lp8557";
+ };
+};
diff --git a/Documentation/lp3943.txt b/Documentation/lp3943.txt
new file mode 100644
index 0000000..576ebd0
--- /dev/null
+++ b/Documentation/lp3943.txt
@@ -0,0 +1,62 @@
+TI/National Semiconductor LP3943 MFD driver
+===========================================
+
+LP3943 is an integrated device capable of driving 16 output channels.
+It can be used for GPIO expander and PWM generators.
+LP3493 registers are controlled via the I2C interface.
+
+Driver structure
+----------------
+ LED control General usage for a device
+ ___________ ____________________________
+
+ LP3943 MFD ---- GPIO expander leds-gpio eg) HW enable pin
+ |
+ --- PWM generator leds-pwm eg) PWM input
+
+
+Why do we need GPIO and PWM drivers instead of LED driver?
+To support LED control and general usage, GPIO and PWM drivers are necessary.
+
+According to the datasheet(1), it's just a LED driver which has 16 channels.
+But here is another application, a GPIO expander.(2)
+
+ (1) http://www.ti.com/lit/ds/snvs256b/snvs256b.pdf
+ (2) http://www.ti.com/lit/an/snva287a/snva287a.pdf
+
+Internal two PWM channels are used for LED dimming effect.
+And each output pin can be used as a GPIO as well.
+LED functionality can work with GPIOs or PWMs.
+LEDs can be controlled with legacy leds-gpio(static brightness) or
+leds-pwm drivers(dynamic brightness control).
+Additionally, it can be used for generic GPIO and PWM controller.
+For example, a GPIO is HW enable pin of a device.
+PWM is input pin of a backlight device.
+
+
+LP3943 PWM port map
+-------------------
+Each PWM channel can be mapped to one or multiple output pins.
+
+For example, PWM 0 is used for a backlight device.
+PWM 1 is for RGB LEDs.
+
+ PWM channel Output pins PWM consumer
+ ___________ ___________ ____________
+ PWM 0 pin 1 backlight
+ PWM 1 pin 7, 8, 9 RGB LEDs
+
+Then, PWM port map is as below.
+PWM 0: num_outputs = 1, output = pin 1
+PWM 1: num_outputs = 3, output = pin 7, 8, 9
+
+The 'lp3943_pwm_map' structure is used for this feature.
+
+
+Device tree supported
+---------------------
+Please refer to the documents below.
+
+Documentation/devicetree/bindings/mfd/lp3943.txt
+Documentation/devicetree/bindings/gpio/gpio-lp3943.txt
+Documentation/devicetree/bindings/pwm/pwm-lp3943.txt
--
1.7.9.5