ist3602 lcd driver
==================

Required properties:
- compatible              : Specify "sony, ist3602"
- sclk-gpios              : SPI-SCLK pin GPIO (Active level=Low)
- mosi-gpios              : SPI-MOSI pin GPIO (Active level=High)
- ss-gpios                : SPI-SS pin GPIO (Active level=Low)
- lcd_en-gpios            : LCD_EN pin GPIO (Optional)
- lcd_rst-gpios           : LCD_RST pin GPIO (Optional)
- dimmer-gpios            : Dimmer control pin GPIO (Optional)
- lcd_bright-gpios        : LCD brightness control pin GPIO (Optional)
- width                   : Number of columns in the LCD module
- height                  : Number of lines in the LCD module
- font_size               : Vertical font size (1-4)
- contrast                : Contrast (0-255)
- ragulation-ratio        : Regulation Ratio (0-15)
- contrast-dimmer         : Contrast when dimmer on (0-255)
- ragulation-ratio-dimmer : Regulation Ratio when dimmer on (0-15l)
- column-offset           : Column address offset (Optional)
- frame-rate              : Frame rate(15-300[Hz])
- bias                    : Set Voltage follow Bias(0:1/4, 1:1/5, 2:1/6, 3:1/7)
- booster                 : Set booster(0:5X, 1:6X, 2:7X, 3:8X)
- boot_message            : Message to be displayed at startup
- dimmer-on-boot          : Whether to enable Dimmer at startup
- enable_dimmer_gpio      : Enable to control Dimmer gpio

Example:
	ist3602 {
		compatible = "sony,ist3602";
		sclk-gpios = <&gpio5 10 GPIO_ACTIVE_LOW>;
		mosi-gpios = <&gpio5 11 GPIO_ACTIVE_HIGH>;
		ss-gpios = <&gpio5 13 GPIO_ACTIVE_LOW>;
		lcd_en-gpios = <&ioexp 18 GPIO_ACTIVE_HIGH>;
		lcd_rst-gpios = <&ioexp 19 GPIO_ACTIVE_LOW>;
		dimmer-gpios = <&ioexp 1 GPIO_ACTIVE_HIGH>;
		lcd_bright-gpios = <&ioexp 22 GPIO_ACTIVE_HIGH>;
		width = <16>;
		height = <2>;
		contrast = <170>;
		regulation-ratio = <8>;
		contrast-dimmer = <90>;
		regulation-ratio-dimmer = <8>;
		column-offset = <8>;
		frame-rate = <70>;
		bias = <0>;
		booster = <0>;
		boot_message = "\f\x1bC\x1bBHELLO";
		dimmer_on_boot;
	};
