drivers/video/backlight/ams369fg06.c - arm/linux-arm64-legacy - Git at Google

 /*
  * ams369fg06 AMOLED LCD panel driver.
  *
  * Copyright (c) 2011 Samsung Electronics Co., Ltd.
  * Author: Jingoo Han  <jg1.han@samsung.com>
  *
  * Derived from drivers/video/s6e63m0.c
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License as published by the
  * Free Software Foundation; either version 2 of the License, or (at your
  * option) any later version.
  */

 #include <linux/backlight.h>
 #include <linux/delay.h>
 #include <linux/fb.h>
 #include <linux/gpio.h>
 #include <linux/lcd.h>
 #include <linux/module.h>
 #include <linux/spi/spi.h>
 #include <linux/wait.h>

 #define SLEEPMSEC		0x1000
 #define ENDDEF			0x2000
 #define	DEFMASK			0xFF00
 #define COMMAND_ONLY		0xFE
 #define DATA_ONLY		0xFF

 #define MAX_GAMMA_LEVEL		5
 #define GAMMA_TABLE_COUNT	21

 #define MIN_BRIGHTNESS		0
 #define MAX_BRIGHTNESS		255
 #define DEFAULT_BRIGHTNESS	150

 struct ams369fg06 {
 	struct device			*dev;
 	struct spi_device		*spi;
 	unsigned int			power;
 	struct lcd_device		*ld;
 	struct backlight_device		*bd;
 	struct lcd_platform_data	*lcd_pd;
 };

 static const unsigned short seq_display_on[] = {
 	0x14, 0x03,
 	ENDDEF, 0x0000
 };

 static const unsigned short seq_display_off[] = {
 	0x14, 0x00,
 	ENDDEF, 0x0000
 };

 static const unsigned short seq_stand_by_on[] = {
 	0x1D, 0xA1,
 	SLEEPMSEC, 200,
 	ENDDEF, 0x0000
 };

 static const unsigned short seq_stand_by_off[] = {
 	0x1D, 0xA0,
 	SLEEPMSEC, 250,
 	ENDDEF, 0x0000
 };

 static const unsigned short seq_setting[] = {
 	0x31, 0x08,
 	0x32, 0x14,
 	0x30, 0x02,
 	0x27, 0x01,
 	0x12, 0x08,
 	0x13, 0x08,
 	0x15, 0x00,
 	0x16, 0x00,

 	0xef, 0xd0,
 	DATA_ONLY, 0xe8,

 	0x39, 0x44,
 	0x40, 0x00,
 	0x41, 0x3f,
 	0x42, 0x2a,
 	0x43, 0x27,
 	0x44, 0x27,
 	0x45, 0x1f,
 	0x46, 0x44,
 	0x50, 0x00,
 	0x51, 0x00,
 	0x52, 0x17,
 	0x53, 0x24,
 	0x54, 0x26,
 	0x55, 0x1f,
 	0x56, 0x43,
 	0x60, 0x00,
 	0x61, 0x3f,
 	0x62, 0x2a,
 	0x63, 0x25,
 	0x64, 0x24,
 	0x65, 0x1b,
 	0x66, 0x5c,

 	0x17, 0x22,
 	0x18, 0x33,
 	0x19, 0x03,
 	0x1a, 0x01,
 	0x22, 0xa4,
 	0x23, 0x00,
 	0x26, 0xa0,

 	0x1d, 0xa0,
 	SLEEPMSEC, 300,

 	0x14, 0x03,

 	ENDDEF, 0x0000
 };

 /* gamma value: 2.2 */
 static const unsigned int ams369fg06_22_250[] = {
 	0x00, 0x3f, 0x2a, 0x27, 0x27, 0x1f, 0x44,
 	0x00, 0x00, 0x17, 0x24, 0x26, 0x1f, 0x43,
 	0x00, 0x3f, 0x2a, 0x25, 0x24, 0x1b, 0x5c,
 };

 static const unsigned int ams369fg06_22_200[] = {
 	0x00, 0x3f, 0x28, 0x29, 0x27, 0x21, 0x3e,
 	0x00, 0x00, 0x10, 0x25, 0x27, 0x20, 0x3d,
 	0x00, 0x3f, 0x28, 0x27, 0x25, 0x1d, 0x53,
 };

 static const unsigned int ams369fg06_22_150[] = {
 	0x00, 0x3f, 0x2d, 0x29, 0x28, 0x23, 0x37,
 	0x00, 0x00, 0x0b, 0x25, 0x28, 0x22, 0x36,
 	0x00, 0x3f, 0x2b, 0x28, 0x26, 0x1f, 0x4a,
 };

 static const unsigned int ams369fg06_22_100[] = {
 	0x00, 0x3f, 0x30, 0x2a, 0x2b, 0x24, 0x2f,
 	0x00, 0x00, 0x00, 0x25, 0x29, 0x24, 0x2e,
 	0x00, 0x3f, 0x2f, 0x29, 0x29, 0x21, 0x3f,
 };

 static const unsigned int ams369fg06_22_50[] = {
 	0x00, 0x3f, 0x3c, 0x2c, 0x2d, 0x27, 0x24,
 	0x00, 0x00, 0x00, 0x22, 0x2a, 0x27, 0x23,
 	0x00, 0x3f, 0x3b, 0x2c, 0x2b, 0x24, 0x31,
 };

 struct ams369fg06_gamma {
 	unsigned int *gamma_22_table[MAX_GAMMA_LEVEL];
 };

 static struct ams369fg06_gamma gamma_table = {
 	.gamma_22_table[0] = (unsigned int *)&ams369fg06_22_50,
 	.gamma_22_table[1] = (unsigned int *)&ams369fg06_22_100,
 	.gamma_22_table[2] = (unsigned int *)&ams369fg06_22_150,
 	.gamma_22_table[3] = (unsigned int *)&ams369fg06_22_200,
 	.gamma_22_table[4] = (unsigned int *)&ams369fg06_22_250,
 };

 static int ams369fg06_spi_write_byte(struct ams369fg06 *lcd, int addr, int data)
 {
 	u16 buf[1];
 	struct spi_message msg;

 	struct spi_transfer xfer = {
 		.len		= 2,
 		.tx_buf		= buf,
 	};

 	buf[0] = (addr << 8) | data;

 	spi_message_init(&msg);
 	spi_message_add_tail(&xfer, &msg);

 	return spi_sync(lcd->spi, &msg);
 }

 static int ams369fg06_spi_write(struct ams369fg06 *lcd, unsigned char address,
 	unsigned char command)
 {
 	int ret = 0;

 	if (address != DATA_ONLY)
 		ret = ams369fg06_spi_write_byte(lcd, 0x70, address);
 	if (command != COMMAND_ONLY)
 		ret = ams369fg06_spi_write_byte(lcd, 0x72, command);

 	return ret;
 }

 static int ams369fg06_panel_send_sequence(struct ams369fg06 *lcd,
 	const unsigned short *wbuf)
 {
 	int ret = 0, i = 0;

 	while ((wbuf[i] & DEFMASK) != ENDDEF) {
 		if ((wbuf[i] & DEFMASK) != SLEEPMSEC) {
 			ret = ams369fg06_spi_write(lcd, wbuf[i], wbuf[i+1]);
 			if (ret)
 				break;
 		} else {
 			msleep(wbuf[i+1]);
 		}
 		i += 2;
 	}

 	return ret;
 }

 static int _ams369fg06_gamma_ctl(struct ams369fg06 *lcd,
 	const unsigned int *gamma)
 {
 	unsigned int i = 0;
 	int ret = 0;

 	for (i = 0 ; i < GAMMA_TABLE_COUNT / 3; i++) {
 		ret = ams369fg06_spi_write(lcd, 0x40 + i, gamma[i]);
 		ret = ams369fg06_spi_write(lcd, 0x50 + i, gamma[i+7*1]);
 		ret = ams369fg06_spi_write(lcd, 0x60 + i, gamma[i+7*2]);
 		if (ret) {
 			dev_err(lcd->dev, "failed to set gamma table.\n");
 			goto gamma_err;
 		}
 	}

 gamma_err:
 	return ret;
 }

 static int ams369fg06_gamma_ctl(struct ams369fg06 *lcd, int brightness)
 {
 	int ret = 0;
 	int gamma = 0;

 	if ((brightness >= 0) && (brightness <= 50))
 		gamma = 0;
 	else if ((brightness > 50) && (brightness <= 100))
 		gamma = 1;
 	else if ((brightness > 100) && (brightness <= 150))
 		gamma = 2;
 	else if ((brightness > 150) && (brightness <= 200))
 		gamma = 3;
 	else if ((brightness > 200) && (brightness <= 255))
 		gamma = 4;

 	ret = _ams369fg06_gamma_ctl(lcd, gamma_table.gamma_22_table[gamma]);

 	return ret;
 }

 static int ams369fg06_ldi_init(struct ams369fg06 *lcd)
 {
 	int ret, i;
 	static const unsigned short *init_seq[] = {
 		seq_setting,
 		seq_stand_by_off,
 	};

 	for (i = 0; i < ARRAY_SIZE(init_seq); i++) {
 		ret = ams369fg06_panel_send_sequence(lcd, init_seq[i]);
 		if (ret)
 			break;
 	}

 	return ret;
 }

 static int ams369fg06_ldi_enable(struct ams369fg06 *lcd)
 {
 	int ret, i;
 	static const unsigned short *init_seq[] = {
 		seq_stand_by_off,
 		seq_display_on,
 	};

 	for (i = 0; i < ARRAY_SIZE(init_seq); i++) {
 		ret = ams369fg06_panel_send_sequence(lcd, init_seq[i]);
 		if (ret)
 			break;
 	}

 	return ret;
 }

 static int ams369fg06_ldi_disable(struct ams369fg06 *lcd)
 {
 	int ret, i;

 	static const unsigned short *init_seq[] = {
 		seq_display_off,
 		seq_stand_by_on,
 	};

 	for (i = 0; i < ARRAY_SIZE(init_seq); i++) {
 		ret = ams369fg06_panel_send_sequence(lcd, init_seq[i]);
 		if (ret)
 			break;
 	}

 	return ret;
 }

 static int ams369fg06_power_is_on(int power)
 {
 	return power <= FB_BLANK_NORMAL;
 }

 static int ams369fg06_power_on(struct ams369fg06 *lcd)
 {
 	int ret = 0;
 	struct lcd_platform_data *pd;
 	struct backlight_device *bd;

 	pd = lcd->lcd_pd;
 	bd = lcd->bd;

 	if (pd->power_on) {
 		pd->power_on(lcd->ld, 1);
 		msleep(pd->power_on_delay);
 	}

 	if (!pd->reset) {
 		dev_err(lcd->dev, "reset is NULL.\n");
 		return -EINVAL;
 	} else {
 		pd->reset(lcd->ld);
 		msleep(pd->reset_delay);
 	}

 	ret = ams369fg06_ldi_init(lcd);
 	if (ret) {
 		dev_err(lcd->dev, "failed to initialize ldi.\n");
 		return ret;
 	}

 	ret = ams369fg06_ldi_enable(lcd);
 	if (ret) {
 		dev_err(lcd->dev, "failed to enable ldi.\n");
 		return ret;
 	}

 	/* set brightness to current value after power on or resume. */
 	ret = ams369fg06_gamma_ctl(lcd, bd->props.brightness);
 	if (ret) {
 		dev_err(lcd->dev, "lcd gamma setting failed.\n");
 		return ret;
 	}

 	return 0;
 }

 static int ams369fg06_power_off(struct ams369fg06 *lcd)
 {
 	int ret;
 	struct lcd_platform_data *pd;

 	pd = lcd->lcd_pd;

 	ret = ams369fg06_ldi_disable(lcd);
 	if (ret) {
 		dev_err(lcd->dev, "lcd setting failed.\n");
 		return -EIO;
 	}

 	msleep(pd->power_off_delay);

 	if (pd->power_on)
 		pd->power_on(lcd->ld, 0);

 	return 0;
 }

 static int ams369fg06_power(struct ams369fg06 *lcd, int power)
 {
 	int ret = 0;

 	if (ams369fg06_power_is_on(power) &&
 		!ams369fg06_power_is_on(lcd->power))
 		ret = ams369fg06_power_on(lcd);
 	else if (!ams369fg06_power_is_on(power) &&
 		ams369fg06_power_is_on(lcd->power))
 		ret = ams369fg06_power_off(lcd);

 	if (!ret)
 		lcd->power = power;

 	return ret;
 }

 static int ams369fg06_get_power(struct lcd_device *ld)
 {
 	struct ams369fg06 *lcd = lcd_get_data(ld);

 	return lcd->power;
 }

 static int ams369fg06_set_power(struct lcd_device *ld, int power)
 {
 	struct ams369fg06 *lcd = lcd_get_data(ld);

 	if (power != FB_BLANK_UNBLANK && power != FB_BLANK_POWERDOWN &&
 		power != FB_BLANK_NORMAL) {
 		dev_err(lcd->dev, "power value should be 0, 1 or 4.\n");
 		return -EINVAL;
 	}

 	return ams369fg06_power(lcd, power);
 }

 static int ams369fg06_get_brightness(struct backlight_device *bd)
 {
 	return bd->props.brightness;
 }

 static int ams369fg06_set_brightness(struct backlight_device *bd)
 {
 	int ret = 0;
 	int brightness = bd->props.brightness;
 	struct ams369fg06 *lcd = bl_get_data(bd);

 	if (brightness < MIN_BRIGHTNESS ||
 		brightness > bd->props.max_brightness) {
 		dev_err(&bd->dev, "lcd brightness should be %d to %d.\n",
 			MIN_BRIGHTNESS, MAX_BRIGHTNESS);
 		return -EINVAL;
 	}

 	ret = ams369fg06_gamma_ctl(lcd, bd->props.brightness);
 	if (ret) {
 		dev_err(&bd->dev, "lcd brightness setting failed.\n");
 		return -EIO;
 	}

 	return ret;
 }

 static struct lcd_ops ams369fg06_lcd_ops = {
 	.get_power = ams369fg06_get_power,
 	.set_power = ams369fg06_set_power,
 };

 static const struct backlight_ops ams369fg06_backlight_ops = {
 	.get_brightness = ams369fg06_get_brightness,
 	.update_status = ams369fg06_set_brightness,
 };

 static int ams369fg06_probe(struct spi_device *spi)
 {
 	int ret = 0;
 	struct ams369fg06 *lcd = NULL;
 	struct lcd_device *ld = NULL;
 	struct backlight_device *bd = NULL;
 	struct backlight_properties props;

 	lcd = devm_kzalloc(&spi->dev, sizeof(struct ams369fg06), GFP_KERNEL);
 	if (!lcd)
 		return -ENOMEM;

 	/* ams369fg06 lcd panel uses 3-wire 16bits SPI Mode. */
 	spi->bits_per_word = 16;

 	ret = spi_setup(spi);
 	if (ret < 0) {
 		dev_err(&spi->dev, "spi setup failed.\n");
 		return ret;
 	}

 	lcd->spi = spi;
 	lcd->dev = &spi->dev;

 	lcd->lcd_pd = dev_get_platdata(&spi->dev);
 	if (!lcd->lcd_pd) {
 		dev_err(&spi->dev, "platform data is NULL\n");
 		return -EINVAL;
 	}

 	ld = devm_lcd_device_register(&spi->dev, "ams369fg06", &spi->dev, lcd,
 					&ams369fg06_lcd_ops);
 	if (IS_ERR(ld))
 		return PTR_ERR(ld);

 	lcd->ld = ld;

 	memset(&props, 0, sizeof(struct backlight_properties));
 	props.type = BACKLIGHT_RAW;
 	props.max_brightness = MAX_BRIGHTNESS;

 	bd = devm_backlight_device_register(&spi->dev, "ams369fg06-bl",
 					&spi->dev, lcd,
 					&ams369fg06_backlight_ops, &props);
 	if (IS_ERR(bd))
 		return PTR_ERR(bd);

 	bd->props.brightness = DEFAULT_BRIGHTNESS;
 	lcd->bd = bd;

 	if (!lcd->lcd_pd->lcd_enabled) {
 		/*
 		 * if lcd panel was off from bootloader then
 		 * current lcd status is powerdown and then
 		 * it enables lcd panel.
 		 */
 		lcd->power = FB_BLANK_POWERDOWN;

 		ams369fg06_power(lcd, FB_BLANK_UNBLANK);
 	} else {
 		lcd->power = FB_BLANK_UNBLANK;
 	}

 	spi_set_drvdata(spi, lcd);

 	dev_info(&spi->dev, "ams369fg06 panel driver has been probed.\n");

 	return 0;
 }

 static int ams369fg06_remove(struct spi_device *spi)
 {
 	struct ams369fg06 *lcd = spi_get_drvdata(spi);

 	ams369fg06_power(lcd, FB_BLANK_POWERDOWN);
 	return 0;
 }

 #ifdef CONFIG_PM_SLEEP
 static int ams369fg06_suspend(struct device *dev)
 {
 	struct ams369fg06 *lcd = dev_get_drvdata(dev);

 	dev_dbg(dev, "lcd->power = %d\n", lcd->power);

 	/*
 	 * when lcd panel is suspend, lcd panel becomes off
 	 * regardless of status.
 	 */
 	return ams369fg06_power(lcd, FB_BLANK_POWERDOWN);
 }

 static int ams369fg06_resume(struct device *dev)
 {
 	struct ams369fg06 *lcd = dev_get_drvdata(dev);

 	lcd->power = FB_BLANK_POWERDOWN;

 	return ams369fg06_power(lcd, FB_BLANK_UNBLANK);
 }
 #endif

 static SIMPLE_DEV_PM_OPS(ams369fg06_pm_ops, ams369fg06_suspend,
 			ams369fg06_resume);

 static void ams369fg06_shutdown(struct spi_device *spi)
 {
 	struct ams369fg06 *lcd = spi_get_drvdata(spi);

 	ams369fg06_power(lcd, FB_BLANK_POWERDOWN);
 }

 static struct spi_driver ams369fg06_driver = {
 	.driver = {
 		.name	= "ams369fg06",
 		.owner	= THIS_MODULE,
 		.pm	= &ams369fg06_pm_ops,
 	},
 	.probe		= ams369fg06_probe,
 	.remove		= ams369fg06_remove,
 	.shutdown	= ams369fg06_shutdown,
 };

 module_spi_driver(ams369fg06_driver);

 MODULE_AUTHOR("Jingoo Han <jg1.han@samsung.com>");
 MODULE_DESCRIPTION("ams369fg06 LCD Driver");
 MODULE_LICENSE("GPL");
	/*
	* ams369fg06 AMOLED LCD panel driver.
	*
	* Copyright (c) 2011 Samsung Electronics Co., Ltd.
	* Author: Jingoo Han <jg1.han@samsung.com>
	*
	* Derived from drivers/video/s6e63m0.c
	*
	* This program is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License as published by the
	* Free Software Foundation; either version 2 of the License, or (at your
	* option) any later version.
	*/

	#include <linux/backlight.h>
	#include <linux/delay.h>
	#include <linux/fb.h>
	#include <linux/gpio.h>
	#include <linux/lcd.h>
	#include <linux/module.h>
	#include <linux/spi/spi.h>
	#include <linux/wait.h>

	#define SLEEPMSEC 0x1000
	#define ENDDEF 0x2000
	#define DEFMASK 0xFF00
	#define COMMAND_ONLY 0xFE
	#define DATA_ONLY 0xFF

	#define MAX_GAMMA_LEVEL 5
	#define GAMMA_TABLE_COUNT 21

	#define MIN_BRIGHTNESS 0
	#define MAX_BRIGHTNESS 255
	#define DEFAULT_BRIGHTNESS 150

	struct ams369fg06 {
	struct device *dev;
	struct spi_device *spi;
	unsigned int power;
	struct lcd_device *ld;
	struct backlight_device *bd;
	struct lcd_platform_data *lcd_pd;
	};

	static const unsigned short seq_display_on[] = {
	0x14, 0x03,
	ENDDEF, 0x0000
	};

	static const unsigned short seq_display_off[] = {
	0x14, 0x00,
	ENDDEF, 0x0000
	};

	static const unsigned short seq_stand_by_on[] = {
	0x1D, 0xA1,
	SLEEPMSEC, 200,
	ENDDEF, 0x0000
	};

	static const unsigned short seq_stand_by_off[] = {
	0x1D, 0xA0,
	SLEEPMSEC, 250,
	ENDDEF, 0x0000
	};

	static const unsigned short seq_setting[] = {
	0x31, 0x08,
	0x32, 0x14,
	0x30, 0x02,
	0x27, 0x01,
	0x12, 0x08,
	0x13, 0x08,
	0x15, 0x00,
	0x16, 0x00,

	0xef, 0xd0,
	DATA_ONLY, 0xe8,

	0x39, 0x44,
	0x40, 0x00,
	0x41, 0x3f,
	0x42, 0x2a,
	0x43, 0x27,
	0x44, 0x27,
	0x45, 0x1f,
	0x46, 0x44,
	0x50, 0x00,
	0x51, 0x00,
	0x52, 0x17,
	0x53, 0x24,
	0x54, 0x26,
	0x55, 0x1f,
	0x56, 0x43,
	0x60, 0x00,
	0x61, 0x3f,
	0x62, 0x2a,
	0x63, 0x25,
	0x64, 0x24,
	0x65, 0x1b,
	0x66, 0x5c,

	0x17, 0x22,
	0x18, 0x33,
	0x19, 0x03,
	0x1a, 0x01,
	0x22, 0xa4,
	0x23, 0x00,
	0x26, 0xa0,

	0x1d, 0xa0,
	SLEEPMSEC, 300,

	0x14, 0x03,

	ENDDEF, 0x0000
	};

	/* gamma value: 2.2 */
	static const unsigned int ams369fg06_22_250[] = {
	0x00, 0x3f, 0x2a, 0x27, 0x27, 0x1f, 0x44,
	0x00, 0x00, 0x17, 0x24, 0x26, 0x1f, 0x43,
	0x00, 0x3f, 0x2a, 0x25, 0x24, 0x1b, 0x5c,
	};

	static const unsigned int ams369fg06_22_200[] = {
	0x00, 0x3f, 0x28, 0x29, 0x27, 0x21, 0x3e,
	0x00, 0x00, 0x10, 0x25, 0x27, 0x20, 0x3d,
	0x00, 0x3f, 0x28, 0x27, 0x25, 0x1d, 0x53,
	};

	static const unsigned int ams369fg06_22_150[] = {
	0x00, 0x3f, 0x2d, 0x29, 0x28, 0x23, 0x37,
	0x00, 0x00, 0x0b, 0x25, 0x28, 0x22, 0x36,
	0x00, 0x3f, 0x2b, 0x28, 0x26, 0x1f, 0x4a,
	};

	static const unsigned int ams369fg06_22_100[] = {
	0x00, 0x3f, 0x30, 0x2a, 0x2b, 0x24, 0x2f,
	0x00, 0x00, 0x00, 0x25, 0x29, 0x24, 0x2e,
	0x00, 0x3f, 0x2f, 0x29, 0x29, 0x21, 0x3f,
	};

	static const unsigned int ams369fg06_22_50[] = {
	0x00, 0x3f, 0x3c, 0x2c, 0x2d, 0x27, 0x24,
	0x00, 0x00, 0x00, 0x22, 0x2a, 0x27, 0x23,
	0x00, 0x3f, 0x3b, 0x2c, 0x2b, 0x24, 0x31,
	};

	struct ams369fg06_gamma {
	unsigned int *gamma_22_table[MAX_GAMMA_LEVEL];
	};

	static struct ams369fg06_gamma gamma_table = {
	.gamma_22_table[0] = (unsigned int *)&ams369fg06_22_50,
	.gamma_22_table[1] = (unsigned int *)&ams369fg06_22_100,
	.gamma_22_table[2] = (unsigned int *)&ams369fg06_22_150,
	.gamma_22_table[3] = (unsigned int *)&ams369fg06_22_200,
	.gamma_22_table[4] = (unsigned int *)&ams369fg06_22_250,
	};

	static int ams369fg06_spi_write_byte(struct ams369fg06 *lcd, int addr, int data)
	{
	u16 buf[1];
	struct spi_message msg;

	struct spi_transfer xfer = {
	.len = 2,
	.tx_buf = buf,
	};

	buf[0] = (addr << 8) \| data;

	spi_message_init(&msg);
	spi_message_add_tail(&xfer, &msg);

	return spi_sync(lcd->spi, &msg);
	}

	static int ams369fg06_spi_write(struct ams369fg06 *lcd, unsigned char address,
	unsigned char command)
	{
	int ret = 0;

	if (address != DATA_ONLY)
	ret = ams369fg06_spi_write_byte(lcd, 0x70, address);
	if (command != COMMAND_ONLY)
	ret = ams369fg06_spi_write_byte(lcd, 0x72, command);

	return ret;
	}

	static int ams369fg06_panel_send_sequence(struct ams369fg06 *lcd,
	const unsigned short *wbuf)
	{
	int ret = 0, i = 0;

	while ((wbuf[i] & DEFMASK) != ENDDEF) {
	if ((wbuf[i] & DEFMASK) != SLEEPMSEC) {
	ret = ams369fg06_spi_write(lcd, wbuf[i], wbuf[i+1]);
	if (ret)
	break;
	} else {
	msleep(wbuf[i+1]);
	}
	i += 2;
	}

	return ret;
	}

	static int _ams369fg06_gamma_ctl(struct ams369fg06 *lcd,
	const unsigned int *gamma)
	{
	unsigned int i = 0;
	int ret = 0;

	for (i = 0 ; i < GAMMA_TABLE_COUNT / 3; i++) {
	ret = ams369fg06_spi_write(lcd, 0x40 + i, gamma[i]);
	ret = ams369fg06_spi_write(lcd, 0x50 + i, gamma[i+7*1]);
	ret = ams369fg06_spi_write(lcd, 0x60 + i, gamma[i+7*2]);
	if (ret) {
	dev_err(lcd->dev, "failed to set gamma table.\n");
	goto gamma_err;
	}
	}

	gamma_err:
	return ret;
	}

	static int ams369fg06_gamma_ctl(struct ams369fg06 *lcd, int brightness)
	{
	int ret = 0;
	int gamma = 0;

	if ((brightness >= 0) && (brightness <= 50))
	gamma = 0;
	else if ((brightness > 50) && (brightness <= 100))
	gamma = 1;
	else if ((brightness > 100) && (brightness <= 150))
	gamma = 2;
	else if ((brightness > 150) && (brightness <= 200))
	gamma = 3;
	else if ((brightness > 200) && (brightness <= 255))
	gamma = 4;

	ret = _ams369fg06_gamma_ctl(lcd, gamma_table.gamma_22_table[gamma]);

	return ret;
	}

	static int ams369fg06_ldi_init(struct ams369fg06 *lcd)
	{
	int ret, i;
	static const unsigned short *init_seq[] = {
	seq_setting,
	seq_stand_by_off,
	};

	for (i = 0; i < ARRAY_SIZE(init_seq); i++) {
	ret = ams369fg06_panel_send_sequence(lcd, init_seq[i]);
	if (ret)
	break;
	}

	return ret;
	}

	static int ams369fg06_ldi_enable(struct ams369fg06 *lcd)
	{
	int ret, i;
	static const unsigned short *init_seq[] = {
	seq_stand_by_off,
	seq_display_on,
	};

	for (i = 0; i < ARRAY_SIZE(init_seq); i++) {
	ret = ams369fg06_panel_send_sequence(lcd, init_seq[i]);
	if (ret)
	break;
	}

	return ret;
	}

	static int ams369fg06_ldi_disable(struct ams369fg06 *lcd)
	{
	int ret, i;

	static const unsigned short *init_seq[] = {
	seq_display_off,
	seq_stand_by_on,
	};

	for (i = 0; i < ARRAY_SIZE(init_seq); i++) {
	ret = ams369fg06_panel_send_sequence(lcd, init_seq[i]);
	if (ret)
	break;
	}

	return ret;
	}

	static int ams369fg06_power_is_on(int power)
	{
	return power <= FB_BLANK_NORMAL;
	}

	static int ams369fg06_power_on(struct ams369fg06 *lcd)
	{
	int ret = 0;
	struct lcd_platform_data *pd;
	struct backlight_device *bd;

	pd = lcd->lcd_pd;
	bd = lcd->bd;

	if (pd->power_on) {
	pd->power_on(lcd->ld, 1);
	msleep(pd->power_on_delay);
	}

	if (!pd->reset) {
	dev_err(lcd->dev, "reset is NULL.\n");
	return -EINVAL;
	} else {
	pd->reset(lcd->ld);
	msleep(pd->reset_delay);
	}

	ret = ams369fg06_ldi_init(lcd);
	if (ret) {
	dev_err(lcd->dev, "failed to initialize ldi.\n");
	return ret;
	}

	ret = ams369fg06_ldi_enable(lcd);
	if (ret) {
	dev_err(lcd->dev, "failed to enable ldi.\n");
	return ret;
	}

	/* set brightness to current value after power on or resume. */
	ret = ams369fg06_gamma_ctl(lcd, bd->props.brightness);
	if (ret) {
	dev_err(lcd->dev, "lcd gamma setting failed.\n");
	return ret;
	}

	return 0;
	}

	static int ams369fg06_power_off(struct ams369fg06 *lcd)
	{
	int ret;
	struct lcd_platform_data *pd;

	pd = lcd->lcd_pd;

	ret = ams369fg06_ldi_disable(lcd);
	if (ret) {
	dev_err(lcd->dev, "lcd setting failed.\n");
	return -EIO;
	}

	msleep(pd->power_off_delay);

	if (pd->power_on)
	pd->power_on(lcd->ld, 0);

	return 0;
	}

	static int ams369fg06_power(struct ams369fg06 *lcd, int power)
	{
	int ret = 0;

	if (ams369fg06_power_is_on(power) &&
	!ams369fg06_power_is_on(lcd->power))
	ret = ams369fg06_power_on(lcd);
	else if (!ams369fg06_power_is_on(power) &&
	ams369fg06_power_is_on(lcd->power))
	ret = ams369fg06_power_off(lcd);

	if (!ret)
	lcd->power = power;

	return ret;
	}

	static int ams369fg06_get_power(struct lcd_device *ld)
	{
	struct ams369fg06 *lcd = lcd_get_data(ld);

	return lcd->power;
	}

	static int ams369fg06_set_power(struct lcd_device *ld, int power)
	{
	struct ams369fg06 *lcd = lcd_get_data(ld);

	if (power != FB_BLANK_UNBLANK && power != FB_BLANK_POWERDOWN &&
	power != FB_BLANK_NORMAL) {
	dev_err(lcd->dev, "power value should be 0, 1 or 4.\n");
	return -EINVAL;
	}

	return ams369fg06_power(lcd, power);
	}

	static int ams369fg06_get_brightness(struct backlight_device *bd)
	{
	return bd->props.brightness;
	}

	static int ams369fg06_set_brightness(struct backlight_device *bd)
	{
	int ret = 0;
	int brightness = bd->props.brightness;
	struct ams369fg06 *lcd = bl_get_data(bd);

	if (brightness < MIN_BRIGHTNESS \|\|
	brightness > bd->props.max_brightness) {
	dev_err(&bd->dev, "lcd brightness should be %d to %d.\n",
	MIN_BRIGHTNESS, MAX_BRIGHTNESS);
	return -EINVAL;
	}

	ret = ams369fg06_gamma_ctl(lcd, bd->props.brightness);
	if (ret) {
	dev_err(&bd->dev, "lcd brightness setting failed.\n");
	return -EIO;
	}

	return ret;
	}

	static struct lcd_ops ams369fg06_lcd_ops = {
	.get_power = ams369fg06_get_power,
	.set_power = ams369fg06_set_power,
	};

	static const struct backlight_ops ams369fg06_backlight_ops = {
	.get_brightness = ams369fg06_get_brightness,
	.update_status = ams369fg06_set_brightness,
	};

	static int ams369fg06_probe(struct spi_device *spi)
	{
	int ret = 0;
	struct ams369fg06 *lcd = NULL;
	struct lcd_device *ld = NULL;
	struct backlight_device *bd = NULL;
	struct backlight_properties props;

	lcd = devm_kzalloc(&spi->dev, sizeof(struct ams369fg06), GFP_KERNEL);
	if (!lcd)
	return -ENOMEM;

	/* ams369fg06 lcd panel uses 3-wire 16bits SPI Mode. */
	spi->bits_per_word = 16;

	ret = spi_setup(spi);
	if (ret < 0) {
	dev_err(&spi->dev, "spi setup failed.\n");
	return ret;
	}

	lcd->spi = spi;
	lcd->dev = &spi->dev;

	lcd->lcd_pd = dev_get_platdata(&spi->dev);
	if (!lcd->lcd_pd) {
	dev_err(&spi->dev, "platform data is NULL\n");
	return -EINVAL;
	}

	ld = devm_lcd_device_register(&spi->dev, "ams369fg06", &spi->dev, lcd,
	&ams369fg06_lcd_ops);
	if (IS_ERR(ld))
	return PTR_ERR(ld);

	lcd->ld = ld;

	memset(&props, 0, sizeof(struct backlight_properties));
	props.type = BACKLIGHT_RAW;
	props.max_brightness = MAX_BRIGHTNESS;

	bd = devm_backlight_device_register(&spi->dev, "ams369fg06-bl",
	&spi->dev, lcd,
	&ams369fg06_backlight_ops, &props);
	if (IS_ERR(bd))
	return PTR_ERR(bd);

	bd->props.brightness = DEFAULT_BRIGHTNESS;
	lcd->bd = bd;

	if (!lcd->lcd_pd->lcd_enabled) {
	/*
	* if lcd panel was off from bootloader then
	* current lcd status is powerdown and then
	* it enables lcd panel.
	*/
	lcd->power = FB_BLANK_POWERDOWN;

	ams369fg06_power(lcd, FB_BLANK_UNBLANK);
	} else {
	lcd->power = FB_BLANK_UNBLANK;
	}

	spi_set_drvdata(spi, lcd);

	dev_info(&spi->dev, "ams369fg06 panel driver has been probed.\n");

	return 0;
	}

	static int ams369fg06_remove(struct spi_device *spi)
	{
	struct ams369fg06 *lcd = spi_get_drvdata(spi);

	ams369fg06_power(lcd, FB_BLANK_POWERDOWN);
	return 0;
	}

	#ifdef CONFIG_PM_SLEEP
	static int ams369fg06_suspend(struct device *dev)
	{
	struct ams369fg06 *lcd = dev_get_drvdata(dev);

	dev_dbg(dev, "lcd->power = %d\n", lcd->power);

	/*
	* when lcd panel is suspend, lcd panel becomes off
	* regardless of status.
	*/
	return ams369fg06_power(lcd, FB_BLANK_POWERDOWN);
	}

	static int ams369fg06_resume(struct device *dev)
	{
	struct ams369fg06 *lcd = dev_get_drvdata(dev);

	lcd->power = FB_BLANK_POWERDOWN;

	return ams369fg06_power(lcd, FB_BLANK_UNBLANK);
	}
	#endif

	static SIMPLE_DEV_PM_OPS(ams369fg06_pm_ops, ams369fg06_suspend,
	ams369fg06_resume);

	static void ams369fg06_shutdown(struct spi_device *spi)
	{
	struct ams369fg06 *lcd = spi_get_drvdata(spi);

	ams369fg06_power(lcd, FB_BLANK_POWERDOWN);
	}

	static struct spi_driver ams369fg06_driver = {
	.driver = {
	.name = "ams369fg06",
	.owner = THIS_MODULE,
	.pm = &ams369fg06_pm_ops,
	},
	.probe = ams369fg06_probe,
	.remove = ams369fg06_remove,
	.shutdown = ams369fg06_shutdown,
	};

	module_spi_driver(ams369fg06_driver);

	MODULE_AUTHOR("Jingoo Han <jg1.han@samsung.com>");
	MODULE_DESCRIPTION("ams369fg06 LCD Driver");
	MODULE_LICENSE("GPL");