drivers/video/backlight/hx8357.c - kernel/msm-4.9 - Gitiles

 /*
  * Driver for the Himax HX-8357 LCD Controller
  *
  * Copyright 2012 Free Electrons
  *
  * Licensed under the GPLv2 or later.
  */

 #include <linux/delay.h>
 #include <linux/lcd.h>
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/of_device.h>
 #include <linux/of_gpio.h>
 #include <linux/spi/spi.h>

 #define HX8357_NUM_IM_PINS	3

 #define HX8357_SWRESET			0x01
 #define HX8357_GET_RED_CHANNEL		0x06
 #define HX8357_GET_GREEN_CHANNEL	0x07
 #define HX8357_GET_BLUE_CHANNEL		0x08
 #define HX8357_GET_POWER_MODE		0x0a
 #define HX8357_GET_MADCTL		0x0b
 #define HX8357_GET_PIXEL_FORMAT		0x0c
 #define HX8357_GET_DISPLAY_MODE		0x0d
 #define HX8357_GET_SIGNAL_MODE		0x0e
 #define HX8357_GET_DIAGNOSTIC_RESULT	0x0f
 #define HX8357_ENTER_SLEEP_MODE		0x10
 #define HX8357_EXIT_SLEEP_MODE		0x11
 #define HX8357_ENTER_PARTIAL_MODE	0x12
 #define HX8357_ENTER_NORMAL_MODE	0x13
 #define HX8357_EXIT_INVERSION_MODE	0x20
 #define HX8357_ENTER_INVERSION_MODE	0x21
 #define HX8357_SET_DISPLAY_OFF		0x28
 #define HX8357_SET_DISPLAY_ON		0x29
 #define HX8357_SET_COLUMN_ADDRESS	0x2a
 #define HX8357_SET_PAGE_ADDRESS		0x2b
 #define HX8357_WRITE_MEMORY_START	0x2c
 #define HX8357_READ_MEMORY_START	0x2e
 #define HX8357_SET_PARTIAL_AREA		0x30
 #define HX8357_SET_SCROLL_AREA		0x33
 #define HX8357_SET_TEAR_OFF		0x34
 #define HX8357_SET_TEAR_ON		0x35
 #define HX8357_SET_ADDRESS_MODE		0x36
 #define HX8357_SET_SCROLL_START		0x37
 #define HX8357_EXIT_IDLE_MODE		0x38
 #define HX8357_ENTER_IDLE_MODE		0x39
 #define HX8357_SET_PIXEL_FORMAT		0x3a
 #define HX8357_SET_PIXEL_FORMAT_DBI_3BIT	(0x1)
 #define HX8357_SET_PIXEL_FORMAT_DBI_16BIT	(0x5)
 #define HX8357_SET_PIXEL_FORMAT_DBI_18BIT	(0x6)
 #define HX8357_SET_PIXEL_FORMAT_DPI_3BIT	(0x1 << 4)
 #define HX8357_SET_PIXEL_FORMAT_DPI_16BIT	(0x5 << 4)
 #define HX8357_SET_PIXEL_FORMAT_DPI_18BIT	(0x6 << 4)
 #define HX8357_WRITE_MEMORY_CONTINUE	0x3c
 #define HX8357_READ_MEMORY_CONTINUE	0x3e
 #define HX8357_SET_TEAR_SCAN_LINES	0x44
 #define HX8357_GET_SCAN_LINES		0x45
 #define HX8357_READ_DDB_START		0xa1
 #define HX8357_SET_DISPLAY_MODE		0xb4
 #define HX8357_SET_DISPLAY_MODE_RGB_THROUGH	(0x3)
 #define HX8357_SET_DISPLAY_MODE_RGB_INTERFACE	(1 << 4)
 #define HX8357_SET_PANEL_DRIVING	0xc0
 #define HX8357_SET_DISPLAY_FRAME	0xc5
 #define HX8357_SET_RGB			0xc6
 #define HX8357_SET_RGB_ENABLE_HIGH		(1 << 1)
 #define HX8357_SET_GAMMA		0xc8
 #define HX8357_SET_POWER		0xd0
 #define HX8357_SET_VCOM			0xd1
 #define HX8357_SET_POWER_NORMAL		0xd2
 #define HX8357_SET_PANEL_RELATED	0xe9

 struct hx8357_data {
 	unsigned		im_pins[HX8357_NUM_IM_PINS];
 	unsigned		reset;
 	struct spi_device	*spi;
 	int			state;
 };

 static u8 hx8357_seq_power[] = {
 	HX8357_SET_POWER, 0x44, 0x41, 0x06,
 };

 static u8 hx8357_seq_vcom[] = {
 	HX8357_SET_VCOM, 0x40, 0x10,
 };

 static u8 hx8357_seq_power_normal[] = {
 	HX8357_SET_POWER_NORMAL, 0x05, 0x12,
 };

 static u8 hx8357_seq_panel_driving[] = {
 	HX8357_SET_PANEL_DRIVING, 0x14, 0x3b, 0x00, 0x02, 0x11,
 };

 static u8 hx8357_seq_display_frame[] = {
 	HX8357_SET_DISPLAY_FRAME, 0x0c,
 };

 static u8 hx8357_seq_panel_related[] = {
 	HX8357_SET_PANEL_RELATED, 0x01,
 };

 static u8 hx8357_seq_undefined1[] = {
 	0xea, 0x03, 0x00, 0x00,
 };

 static u8 hx8357_seq_undefined2[] = {
 	0xeb, 0x40, 0x54, 0x26, 0xdb,
 };

 static u8 hx8357_seq_gamma[] = {
 	HX8357_SET_GAMMA, 0x00, 0x15, 0x00, 0x22, 0x00,
 	0x08, 0x77, 0x26, 0x77, 0x22, 0x04, 0x00,
 };

 static u8 hx8357_seq_address_mode[] = {
 	HX8357_SET_ADDRESS_MODE, 0xc0,
 };

 static u8 hx8357_seq_pixel_format[] = {
 	HX8357_SET_PIXEL_FORMAT,
 	HX8357_SET_PIXEL_FORMAT_DPI_18BIT |
 	HX8357_SET_PIXEL_FORMAT_DBI_18BIT,
 };

 static u8 hx8357_seq_column_address[] = {
 	HX8357_SET_COLUMN_ADDRESS, 0x00, 0x00, 0x01, 0x3f,
 };

 static u8 hx8357_seq_page_address[] = {
 	HX8357_SET_PAGE_ADDRESS, 0x00, 0x00, 0x01, 0xdf,
 };

 static u8 hx8357_seq_rgb[] = {
 	HX8357_SET_RGB, 0x02,
 };

 static u8 hx8357_seq_display_mode[] = {
 	HX8357_SET_DISPLAY_MODE,
 	HX8357_SET_DISPLAY_MODE_RGB_THROUGH |
 	HX8357_SET_DISPLAY_MODE_RGB_INTERFACE,
 };

 static int hx8357_spi_write_then_read(struct lcd_device *lcdev,
 				u8 *txbuf, u16 txlen,
 				u8 *rxbuf, u16 rxlen)
 {
 	struct hx8357_data *lcd = lcd_get_data(lcdev);
 	struct spi_message msg;
 	struct spi_transfer xfer[2];
 	u16 *local_txbuf = NULL;
 	int ret = 0;

 	memset(xfer, 0, sizeof(xfer));
 	spi_message_init(&msg);

 	if (txlen) {
 		int i;

 		local_txbuf = kcalloc(txlen, sizeof(*local_txbuf), GFP_KERNEL);

 		if (!local_txbuf)
 			return -ENOMEM;

 		for (i = 0; i < txlen; i++) {
 			local_txbuf[i] = txbuf[i];
 			if (i > 0)
 				local_txbuf[i] |= 1 << 8;
 		}

 		xfer[0].len = 2 * txlen;
 		xfer[0].bits_per_word = 9;
 		xfer[0].tx_buf = local_txbuf;
 		spi_message_add_tail(&xfer[0], &msg);
 	}

 	if (rxlen) {
 		xfer[1].len = rxlen;
 		xfer[1].bits_per_word = 8;
 		xfer[1].rx_buf = rxbuf;
 		spi_message_add_tail(&xfer[1], &msg);
 	}

 	ret = spi_sync(lcd->spi, &msg);
 	if (ret < 0)
 		dev_err(&lcdev->dev, "Couldn't send SPI data\n");

 	if (txlen)
 		kfree(local_txbuf);

 	return ret;
 }

 static inline int hx8357_spi_write_array(struct lcd_device *lcdev,
 					u8 *value, u8 len)
 {
 	return hx8357_spi_write_then_read(lcdev, value, len, NULL, 0);
 }

 static inline int hx8357_spi_write_byte(struct lcd_device *lcdev,
 					u8 value)
 {
 	return hx8357_spi_write_then_read(lcdev, &value, 1, NULL, 0);
 }

 static int hx8357_enter_standby(struct lcd_device *lcdev)
 {
 	int ret;

 	ret = hx8357_spi_write_byte(lcdev, HX8357_SET_DISPLAY_OFF);
 	if (ret < 0)
 		return ret;

 	usleep_range(10000, 12000);

 	ret = hx8357_spi_write_byte(lcdev, HX8357_ENTER_SLEEP_MODE);
 	if (ret < 0)
 		return ret;

 	msleep(120);

 	return 0;
 }

 static int hx8357_exit_standby(struct lcd_device *lcdev)
 {
 	int ret;

 	ret = hx8357_spi_write_byte(lcdev, HX8357_EXIT_SLEEP_MODE);
 	if (ret < 0)
 		return ret;

 	msleep(120);

 	ret = hx8357_spi_write_byte(lcdev, HX8357_SET_DISPLAY_ON);
 	if (ret < 0)
 		return ret;

 	return 0;
 }

 static int hx8357_lcd_init(struct lcd_device *lcdev)
 {
 	struct hx8357_data *lcd = lcd_get_data(lcdev);
 	int ret;

 	/*
 	 * Set the interface selection pins to SPI mode, with three
 	 * wires
 	 */
 	gpio_set_value_cansleep(lcd->im_pins[0], 1);
 	gpio_set_value_cansleep(lcd->im_pins[1], 0);
 	gpio_set_value_cansleep(lcd->im_pins[2], 1);

 	/* Reset the screen */
 	gpio_set_value(lcd->reset, 1);
 	usleep_range(10000, 12000);
 	gpio_set_value(lcd->reset, 0);
 	usleep_range(10000, 12000);
 	gpio_set_value(lcd->reset, 1);
 	msleep(120);

 	ret = hx8357_spi_write_array(lcdev, hx8357_seq_power,
 				ARRAY_SIZE(hx8357_seq_power));
 	if (ret < 0)
 		return ret;

 	ret = hx8357_spi_write_array(lcdev, hx8357_seq_vcom,
 				ARRAY_SIZE(hx8357_seq_vcom));
 	if (ret < 0)
 		return ret;

 	ret = hx8357_spi_write_array(lcdev, hx8357_seq_power_normal,
 				ARRAY_SIZE(hx8357_seq_power_normal));
 	if (ret < 0)
 		return ret;

 	ret = hx8357_spi_write_array(lcdev, hx8357_seq_panel_driving,
 				ARRAY_SIZE(hx8357_seq_panel_driving));
 	if (ret < 0)
 		return ret;

 	ret = hx8357_spi_write_array(lcdev, hx8357_seq_display_frame,
 				ARRAY_SIZE(hx8357_seq_display_frame));
 	if (ret < 0)
 		return ret;

 	ret = hx8357_spi_write_array(lcdev, hx8357_seq_panel_related,
 				ARRAY_SIZE(hx8357_seq_panel_related));
 	if (ret < 0)
 		return ret;

 	ret = hx8357_spi_write_array(lcdev, hx8357_seq_undefined1,
 				ARRAY_SIZE(hx8357_seq_undefined1));
 	if (ret < 0)
 		return ret;

 	ret = hx8357_spi_write_array(lcdev, hx8357_seq_undefined2,
 				ARRAY_SIZE(hx8357_seq_undefined2));
 	if (ret < 0)
 		return ret;

 	ret = hx8357_spi_write_array(lcdev, hx8357_seq_gamma,
 				ARRAY_SIZE(hx8357_seq_gamma));
 	if (ret < 0)
 		return ret;

 	ret = hx8357_spi_write_array(lcdev, hx8357_seq_address_mode,
 				ARRAY_SIZE(hx8357_seq_address_mode));
 	if (ret < 0)
 		return ret;

 	ret = hx8357_spi_write_array(lcdev, hx8357_seq_pixel_format,
 				ARRAY_SIZE(hx8357_seq_pixel_format));
 	if (ret < 0)
 		return ret;

 	ret = hx8357_spi_write_array(lcdev, hx8357_seq_column_address,
 				ARRAY_SIZE(hx8357_seq_column_address));
 	if (ret < 0)
 		return ret;

 	ret = hx8357_spi_write_array(lcdev, hx8357_seq_page_address,
 				ARRAY_SIZE(hx8357_seq_page_address));
 	if (ret < 0)
 		return ret;

 	ret = hx8357_spi_write_array(lcdev, hx8357_seq_rgb,
 				ARRAY_SIZE(hx8357_seq_rgb));
 	if (ret < 0)
 		return ret;

 	ret = hx8357_spi_write_array(lcdev, hx8357_seq_display_mode,
 				ARRAY_SIZE(hx8357_seq_display_mode));
 	if (ret < 0)
 		return ret;

 	ret = hx8357_spi_write_byte(lcdev, HX8357_EXIT_SLEEP_MODE);
 	if (ret < 0)
 		return ret;

 	msleep(120);

 	ret = hx8357_spi_write_byte(lcdev, HX8357_SET_DISPLAY_ON);
 	if (ret < 0)
 		return ret;

 	usleep_range(5000, 7000);

 	ret = hx8357_spi_write_byte(lcdev, HX8357_WRITE_MEMORY_START);
 	if (ret < 0)
 		return ret;

 	return 0;
 }

 #define POWER_IS_ON(pwr)	((pwr) <= FB_BLANK_NORMAL)

 static int hx8357_set_power(struct lcd_device *lcdev, int power)
 {
 	struct hx8357_data *lcd = lcd_get_data(lcdev);
 	int ret = 0;

 	if (POWER_IS_ON(power) && !POWER_IS_ON(lcd->state))
 		ret = hx8357_exit_standby(lcdev);
 	else if (!POWER_IS_ON(power) && POWER_IS_ON(lcd->state))
 		ret = hx8357_enter_standby(lcdev);

 	if (ret == 0)
 		lcd->state = power;
 	else
 		dev_warn(&lcdev->dev, "failed to set power mode %d\n", power);

 	return ret;
 }

 static int hx8357_get_power(struct lcd_device *lcdev)
 {
 	struct hx8357_data *lcd = lcd_get_data(lcdev);

 	return lcd->state;
 }

 static struct lcd_ops hx8357_ops = {
 	.set_power	= hx8357_set_power,
 	.get_power	= hx8357_get_power,
 };

 static int hx8357_probe(struct spi_device *spi)
 {
 	struct lcd_device *lcdev;
 	struct hx8357_data *lcd;
 	int i, ret;

 	lcd = devm_kzalloc(&spi->dev, sizeof(*lcd), GFP_KERNEL);
 	if (!lcd) {
 		dev_err(&spi->dev, "Couldn't allocate lcd internal structure!\n");
 		return -ENOMEM;
 	}

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

 	lcd->spi = spi;

 	lcd->reset = of_get_named_gpio(spi->dev.of_node, "gpios-reset", 0);
 	if (!gpio_is_valid(lcd->reset)) {
 		dev_err(&spi->dev, "Missing dt property: gpios-reset\n");
 		return -EINVAL;
 	}

 	ret = devm_gpio_request_one(&spi->dev, lcd->reset,
 				    GPIOF_OUT_INIT_HIGH,
 				    "hx8357-reset");
 	if (ret) {
 		dev_err(&spi->dev,
 			"failed to request gpio %d: %d\n",
 			lcd->reset, ret);
 		return -EINVAL;
 	}

 	for (i = 0; i < HX8357_NUM_IM_PINS; i++) {
 		lcd->im_pins[i] = of_get_named_gpio(spi->dev.of_node,
 						"im-gpios", i);
 		if (lcd->im_pins[i] == -EPROBE_DEFER) {
 			dev_info(&spi->dev, "GPIO requested is not here yet, deferring the probe\n");
 			return -EPROBE_DEFER;
 		}
 		if (!gpio_is_valid(lcd->im_pins[i])) {
 			dev_err(&spi->dev, "Missing dt property: im-gpios\n");
 			return -EINVAL;
 		}

 		ret = devm_gpio_request_one(&spi->dev, lcd->im_pins[i],
 					GPIOF_OUT_INIT_LOW, "im_pins");
 		if (ret) {
 			dev_err(&spi->dev, "failed to request gpio %d: %d\n",
 				lcd->im_pins[i], ret);
 			return -EINVAL;
 		}
 	}

 	lcdev = lcd_device_register("mxsfb", &spi->dev, lcd, &hx8357_ops);
 	if (IS_ERR(lcdev)) {
 		ret = PTR_ERR(lcdev);
 		return ret;
 	}
 	spi_set_drvdata(spi, lcdev);

 	ret = hx8357_lcd_init(lcdev);
 	if (ret) {
 		dev_err(&spi->dev, "Couldn't initialize panel\n");
 		goto init_error;
 	}

 	dev_info(&spi->dev, "Panel probed\n");

 	return 0;

 init_error:
 	lcd_device_unregister(lcdev);
 	return ret;
 }

 static int hx8357_remove(struct spi_device *spi)
 {
 	struct lcd_device *lcdev = spi_get_drvdata(spi);

 	lcd_device_unregister(lcdev);
 	return 0;
 }

 static const struct of_device_id hx8357_dt_ids[] = {
 	{ .compatible = "himax,hx8357" },
 	{},
 };
 MODULE_DEVICE_TABLE(of, hx8357_dt_ids);

 static struct spi_driver hx8357_driver = {
 	.probe  = hx8357_probe,
 	.remove = hx8357_remove,
 	.driver = {
 		.name = "hx8357",
 		.of_match_table = of_match_ptr(hx8357_dt_ids),
 	},
 };

 module_spi_driver(hx8357_driver);

 MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
 MODULE_DESCRIPTION("Himax HX-8357 LCD Driver");
 MODULE_LICENSE("GPL");
	/*
	* Driver for the Himax HX-8357 LCD Controller
	*
	* Copyright 2012 Free Electrons
	*
	* Licensed under the GPLv2 or later.
	*/

	#include <linux/delay.h>
	#include <linux/lcd.h>
	#include <linux/module.h>
	#include <linux/of.h>
	#include <linux/of_device.h>
	#include <linux/of_gpio.h>
	#include <linux/spi/spi.h>

	#define HX8357_NUM_IM_PINS 3

	#define HX8357_SWRESET 0x01
	#define HX8357_GET_RED_CHANNEL 0x06
	#define HX8357_GET_GREEN_CHANNEL 0x07
	#define HX8357_GET_BLUE_CHANNEL 0x08
	#define HX8357_GET_POWER_MODE 0x0a
	#define HX8357_GET_MADCTL 0x0b
	#define HX8357_GET_PIXEL_FORMAT 0x0c
	#define HX8357_GET_DISPLAY_MODE 0x0d
	#define HX8357_GET_SIGNAL_MODE 0x0e
	#define HX8357_GET_DIAGNOSTIC_RESULT 0x0f
	#define HX8357_ENTER_SLEEP_MODE 0x10
	#define HX8357_EXIT_SLEEP_MODE 0x11
	#define HX8357_ENTER_PARTIAL_MODE 0x12
	#define HX8357_ENTER_NORMAL_MODE 0x13
	#define HX8357_EXIT_INVERSION_MODE 0x20
	#define HX8357_ENTER_INVERSION_MODE 0x21
	#define HX8357_SET_DISPLAY_OFF 0x28
	#define HX8357_SET_DISPLAY_ON 0x29
	#define HX8357_SET_COLUMN_ADDRESS 0x2a
	#define HX8357_SET_PAGE_ADDRESS 0x2b
	#define HX8357_WRITE_MEMORY_START 0x2c
	#define HX8357_READ_MEMORY_START 0x2e
	#define HX8357_SET_PARTIAL_AREA 0x30
	#define HX8357_SET_SCROLL_AREA 0x33
	#define HX8357_SET_TEAR_OFF 0x34
	#define HX8357_SET_TEAR_ON 0x35
	#define HX8357_SET_ADDRESS_MODE 0x36
	#define HX8357_SET_SCROLL_START 0x37
	#define HX8357_EXIT_IDLE_MODE 0x38
	#define HX8357_ENTER_IDLE_MODE 0x39
	#define HX8357_SET_PIXEL_FORMAT 0x3a
	#define HX8357_SET_PIXEL_FORMAT_DBI_3BIT (0x1)
	#define HX8357_SET_PIXEL_FORMAT_DBI_16BIT (0x5)
	#define HX8357_SET_PIXEL_FORMAT_DBI_18BIT (0x6)
	#define HX8357_SET_PIXEL_FORMAT_DPI_3BIT (0x1 << 4)
	#define HX8357_SET_PIXEL_FORMAT_DPI_16BIT (0x5 << 4)
	#define HX8357_SET_PIXEL_FORMAT_DPI_18BIT (0x6 << 4)
	#define HX8357_WRITE_MEMORY_CONTINUE 0x3c
	#define HX8357_READ_MEMORY_CONTINUE 0x3e
	#define HX8357_SET_TEAR_SCAN_LINES 0x44
	#define HX8357_GET_SCAN_LINES 0x45
	#define HX8357_READ_DDB_START 0xa1
	#define HX8357_SET_DISPLAY_MODE 0xb4
	#define HX8357_SET_DISPLAY_MODE_RGB_THROUGH (0x3)
	#define HX8357_SET_DISPLAY_MODE_RGB_INTERFACE (1 << 4)
	#define HX8357_SET_PANEL_DRIVING 0xc0
	#define HX8357_SET_DISPLAY_FRAME 0xc5
	#define HX8357_SET_RGB 0xc6
	#define HX8357_SET_RGB_ENABLE_HIGH (1 << 1)
	#define HX8357_SET_GAMMA 0xc8
	#define HX8357_SET_POWER 0xd0
	#define HX8357_SET_VCOM 0xd1
	#define HX8357_SET_POWER_NORMAL 0xd2
	#define HX8357_SET_PANEL_RELATED 0xe9

	struct hx8357_data {
	unsigned im_pins[HX8357_NUM_IM_PINS];
	unsigned reset;
	struct spi_device *spi;
	int state;
	};

	static u8 hx8357_seq_power[] = {
	HX8357_SET_POWER, 0x44, 0x41, 0x06,
	};

	static u8 hx8357_seq_vcom[] = {
	HX8357_SET_VCOM, 0x40, 0x10,
	};

	static u8 hx8357_seq_power_normal[] = {
	HX8357_SET_POWER_NORMAL, 0x05, 0x12,
	};

	static u8 hx8357_seq_panel_driving[] = {
	HX8357_SET_PANEL_DRIVING, 0x14, 0x3b, 0x00, 0x02, 0x11,
	};

	static u8 hx8357_seq_display_frame[] = {
	HX8357_SET_DISPLAY_FRAME, 0x0c,
	};

	static u8 hx8357_seq_panel_related[] = {
	HX8357_SET_PANEL_RELATED, 0x01,
	};

	static u8 hx8357_seq_undefined1[] = {
	0xea, 0x03, 0x00, 0x00,
	};

	static u8 hx8357_seq_undefined2[] = {
	0xeb, 0x40, 0x54, 0x26, 0xdb,
	};

	static u8 hx8357_seq_gamma[] = {
	HX8357_SET_GAMMA, 0x00, 0x15, 0x00, 0x22, 0x00,
	0x08, 0x77, 0x26, 0x77, 0x22, 0x04, 0x00,
	};

	static u8 hx8357_seq_address_mode[] = {
	HX8357_SET_ADDRESS_MODE, 0xc0,
	};

	static u8 hx8357_seq_pixel_format[] = {
	HX8357_SET_PIXEL_FORMAT,
	HX8357_SET_PIXEL_FORMAT_DPI_18BIT \|
	HX8357_SET_PIXEL_FORMAT_DBI_18BIT,
	};

	static u8 hx8357_seq_column_address[] = {
	HX8357_SET_COLUMN_ADDRESS, 0x00, 0x00, 0x01, 0x3f,
	};

	static u8 hx8357_seq_page_address[] = {
	HX8357_SET_PAGE_ADDRESS, 0x00, 0x00, 0x01, 0xdf,
	};

	static u8 hx8357_seq_rgb[] = {
	HX8357_SET_RGB, 0x02,
	};

	static u8 hx8357_seq_display_mode[] = {
	HX8357_SET_DISPLAY_MODE,
	HX8357_SET_DISPLAY_MODE_RGB_THROUGH \|
	HX8357_SET_DISPLAY_MODE_RGB_INTERFACE,
	};

	static int hx8357_spi_write_then_read(struct lcd_device *lcdev,
	u8 *txbuf, u16 txlen,
	u8 *rxbuf, u16 rxlen)
	{
	struct hx8357_data *lcd = lcd_get_data(lcdev);
	struct spi_message msg;
	struct spi_transfer xfer[2];
	u16 *local_txbuf = NULL;
	int ret = 0;

	memset(xfer, 0, sizeof(xfer));
	spi_message_init(&msg);

	if (txlen) {
	int i;

	local_txbuf = kcalloc(txlen, sizeof(*local_txbuf), GFP_KERNEL);

	if (!local_txbuf)
	return -ENOMEM;

	for (i = 0; i < txlen; i++) {
	local_txbuf[i] = txbuf[i];
	if (i > 0)
	local_txbuf[i] \|= 1 << 8;
	}

	xfer[0].len = 2 * txlen;
	xfer[0].bits_per_word = 9;
	xfer[0].tx_buf = local_txbuf;
	spi_message_add_tail(&xfer[0], &msg);
	}

	if (rxlen) {
	xfer[1].len = rxlen;
	xfer[1].bits_per_word = 8;
	xfer[1].rx_buf = rxbuf;
	spi_message_add_tail(&xfer[1], &msg);
	}

	ret = spi_sync(lcd->spi, &msg);
	if (ret < 0)
	dev_err(&lcdev->dev, "Couldn't send SPI data\n");

	if (txlen)
	kfree(local_txbuf);

	return ret;
	}

	static inline int hx8357_spi_write_array(struct lcd_device *lcdev,
	u8 *value, u8 len)
	{
	return hx8357_spi_write_then_read(lcdev, value, len, NULL, 0);
	}

	static inline int hx8357_spi_write_byte(struct lcd_device *lcdev,
	u8 value)
	{
	return hx8357_spi_write_then_read(lcdev, &value, 1, NULL, 0);
	}

	static int hx8357_enter_standby(struct lcd_device *lcdev)
	{
	int ret;

	ret = hx8357_spi_write_byte(lcdev, HX8357_SET_DISPLAY_OFF);
	if (ret < 0)
	return ret;

	usleep_range(10000, 12000);

	ret = hx8357_spi_write_byte(lcdev, HX8357_ENTER_SLEEP_MODE);
	if (ret < 0)
	return ret;

	msleep(120);

	return 0;
	}

	static int hx8357_exit_standby(struct lcd_device *lcdev)
	{
	int ret;

	ret = hx8357_spi_write_byte(lcdev, HX8357_EXIT_SLEEP_MODE);
	if (ret < 0)
	return ret;

	msleep(120);

	ret = hx8357_spi_write_byte(lcdev, HX8357_SET_DISPLAY_ON);
	if (ret < 0)
	return ret;

	return 0;
	}

	static int hx8357_lcd_init(struct lcd_device *lcdev)
	{
	struct hx8357_data *lcd = lcd_get_data(lcdev);
	int ret;

	/*
	* Set the interface selection pins to SPI mode, with three
	* wires
	*/
	gpio_set_value_cansleep(lcd->im_pins[0], 1);
	gpio_set_value_cansleep(lcd->im_pins[1], 0);
	gpio_set_value_cansleep(lcd->im_pins[2], 1);

	/* Reset the screen */
	gpio_set_value(lcd->reset, 1);
	usleep_range(10000, 12000);
	gpio_set_value(lcd->reset, 0);
	usleep_range(10000, 12000);
	gpio_set_value(lcd->reset, 1);
	msleep(120);

	ret = hx8357_spi_write_array(lcdev, hx8357_seq_power,
	ARRAY_SIZE(hx8357_seq_power));
	if (ret < 0)
	return ret;

	ret = hx8357_spi_write_array(lcdev, hx8357_seq_vcom,
	ARRAY_SIZE(hx8357_seq_vcom));
	if (ret < 0)
	return ret;

	ret = hx8357_spi_write_array(lcdev, hx8357_seq_power_normal,
	ARRAY_SIZE(hx8357_seq_power_normal));
	if (ret < 0)
	return ret;

	ret = hx8357_spi_write_array(lcdev, hx8357_seq_panel_driving,
	ARRAY_SIZE(hx8357_seq_panel_driving));
	if (ret < 0)
	return ret;

	ret = hx8357_spi_write_array(lcdev, hx8357_seq_display_frame,
	ARRAY_SIZE(hx8357_seq_display_frame));
	if (ret < 0)
	return ret;

	ret = hx8357_spi_write_array(lcdev, hx8357_seq_panel_related,
	ARRAY_SIZE(hx8357_seq_panel_related));
	if (ret < 0)
	return ret;

	ret = hx8357_spi_write_array(lcdev, hx8357_seq_undefined1,
	ARRAY_SIZE(hx8357_seq_undefined1));
	if (ret < 0)
	return ret;

	ret = hx8357_spi_write_array(lcdev, hx8357_seq_undefined2,
	ARRAY_SIZE(hx8357_seq_undefined2));
	if (ret < 0)
	return ret;

	ret = hx8357_spi_write_array(lcdev, hx8357_seq_gamma,
	ARRAY_SIZE(hx8357_seq_gamma));
	if (ret < 0)
	return ret;

	ret = hx8357_spi_write_array(lcdev, hx8357_seq_address_mode,
	ARRAY_SIZE(hx8357_seq_address_mode));
	if (ret < 0)
	return ret;

	ret = hx8357_spi_write_array(lcdev, hx8357_seq_pixel_format,
	ARRAY_SIZE(hx8357_seq_pixel_format));
	if (ret < 0)
	return ret;

	ret = hx8357_spi_write_array(lcdev, hx8357_seq_column_address,
	ARRAY_SIZE(hx8357_seq_column_address));
	if (ret < 0)
	return ret;

	ret = hx8357_spi_write_array(lcdev, hx8357_seq_page_address,
	ARRAY_SIZE(hx8357_seq_page_address));
	if (ret < 0)
	return ret;

	ret = hx8357_spi_write_array(lcdev, hx8357_seq_rgb,
	ARRAY_SIZE(hx8357_seq_rgb));
	if (ret < 0)
	return ret;

	ret = hx8357_spi_write_array(lcdev, hx8357_seq_display_mode,
	ARRAY_SIZE(hx8357_seq_display_mode));
	if (ret < 0)
	return ret;

	ret = hx8357_spi_write_byte(lcdev, HX8357_EXIT_SLEEP_MODE);
	if (ret < 0)
	return ret;

	msleep(120);

	ret = hx8357_spi_write_byte(lcdev, HX8357_SET_DISPLAY_ON);
	if (ret < 0)
	return ret;

	usleep_range(5000, 7000);

	ret = hx8357_spi_write_byte(lcdev, HX8357_WRITE_MEMORY_START);
	if (ret < 0)
	return ret;

	return 0;
	}

	#define POWER_IS_ON(pwr) ((pwr) <= FB_BLANK_NORMAL)

	static int hx8357_set_power(struct lcd_device *lcdev, int power)
	{
	struct hx8357_data *lcd = lcd_get_data(lcdev);
	int ret = 0;

	if (POWER_IS_ON(power) && !POWER_IS_ON(lcd->state))
	ret = hx8357_exit_standby(lcdev);
	else if (!POWER_IS_ON(power) && POWER_IS_ON(lcd->state))
	ret = hx8357_enter_standby(lcdev);

	if (ret == 0)
	lcd->state = power;
	else
	dev_warn(&lcdev->dev, "failed to set power mode %d\n", power);

	return ret;
	}

	static int hx8357_get_power(struct lcd_device *lcdev)
	{
	struct hx8357_data *lcd = lcd_get_data(lcdev);

	return lcd->state;
	}

	static struct lcd_ops hx8357_ops = {
	.set_power = hx8357_set_power,
	.get_power = hx8357_get_power,
	};

	static int hx8357_probe(struct spi_device *spi)
	{
	struct lcd_device *lcdev;
	struct hx8357_data *lcd;
	int i, ret;

	lcd = devm_kzalloc(&spi->dev, sizeof(*lcd), GFP_KERNEL);
	if (!lcd) {
	dev_err(&spi->dev, "Couldn't allocate lcd internal structure!\n");
	return -ENOMEM;
	}

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

	lcd->spi = spi;

	lcd->reset = of_get_named_gpio(spi->dev.of_node, "gpios-reset", 0);
	if (!gpio_is_valid(lcd->reset)) {
	dev_err(&spi->dev, "Missing dt property: gpios-reset\n");
	return -EINVAL;
	}

	ret = devm_gpio_request_one(&spi->dev, lcd->reset,
	GPIOF_OUT_INIT_HIGH,
	"hx8357-reset");
	if (ret) {
	dev_err(&spi->dev,
	"failed to request gpio %d: %d\n",
	lcd->reset, ret);
	return -EINVAL;
	}

	for (i = 0; i < HX8357_NUM_IM_PINS; i++) {
	lcd->im_pins[i] = of_get_named_gpio(spi->dev.of_node,
	"im-gpios", i);
	if (lcd->im_pins[i] == -EPROBE_DEFER) {
	dev_info(&spi->dev, "GPIO requested is not here yet, deferring the probe\n");
	return -EPROBE_DEFER;
	}
	if (!gpio_is_valid(lcd->im_pins[i])) {
	dev_err(&spi->dev, "Missing dt property: im-gpios\n");
	return -EINVAL;
	}

	ret = devm_gpio_request_one(&spi->dev, lcd->im_pins[i],
	GPIOF_OUT_INIT_LOW, "im_pins");
	if (ret) {
	dev_err(&spi->dev, "failed to request gpio %d: %d\n",
	lcd->im_pins[i], ret);
	return -EINVAL;
	}
	}

	lcdev = lcd_device_register("mxsfb", &spi->dev, lcd, &hx8357_ops);
	if (IS_ERR(lcdev)) {
	ret = PTR_ERR(lcdev);
	return ret;
	}
	spi_set_drvdata(spi, lcdev);

	ret = hx8357_lcd_init(lcdev);
	if (ret) {
	dev_err(&spi->dev, "Couldn't initialize panel\n");
	goto init_error;
	}

	dev_info(&spi->dev, "Panel probed\n");

	return 0;

	init_error:
	lcd_device_unregister(lcdev);
	return ret;
	}

	static int hx8357_remove(struct spi_device *spi)
	{
	struct lcd_device *lcdev = spi_get_drvdata(spi);

	lcd_device_unregister(lcdev);
	return 0;
	}

	static const struct of_device_id hx8357_dt_ids[] = {
	{ .compatible = "himax,hx8357" },
	{},
	};
	MODULE_DEVICE_TABLE(of, hx8357_dt_ids);

	static struct spi_driver hx8357_driver = {
	.probe = hx8357_probe,
	.remove = hx8357_remove,
	.driver = {
	.name = "hx8357",
	.of_match_table = of_match_ptr(hx8357_dt_ids),
	},
	};

	module_spi_driver(hx8357_driver);

	MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
	MODULE_DESCRIPTION("Himax HX-8357 LCD Driver");
	MODULE_LICENSE("GPL");