drivers/video/backlight/ltv350qv.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * Power control for Samsung LTV350QV Quarter VGA LCD Panel
  *
  * Copyright (C) 2006, 2007 Atmel Corporation
  */
 #include <linux/delay.h>
 #include <linux/err.h>
 #include <linux/fb.h>
 #include <linux/init.h>
 #include <linux/lcd.h>
 #include <linux/module.h>
 #include <linux/slab.h>
 #include <linux/spi/spi.h>

 #include "ltv350qv.h"

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

 struct ltv350qv {
 	struct spi_device	*spi;
 	u8			*buffer;
 	int			power;
 	struct lcd_device	*ld;
 };

 /*
  * The power-on and power-off sequences are taken from the
  * LTV350QV-F04 data sheet from Samsung. The register definitions are
  * taken from the S6F2002 command list also from Samsung.
  *
  * There's still some voodoo going on here, but it's a lot better than
  * in the first incarnation of the driver where all we had was the raw
  * numbers from the initialization sequence.
  */
 static int ltv350qv_write_reg(struct ltv350qv *lcd, u8 reg, u16 val)
 {
 	struct spi_message msg;
 	struct spi_transfer index_xfer = {
 		.len		= 3,
 		.cs_change	= 1,
 	};
 	struct spi_transfer value_xfer = {
 		.len		= 3,
 	};

 	spi_message_init(&msg);

 	/* register index */
 	lcd->buffer[0] = LTV_OPC_INDEX;
 	lcd->buffer[1] = 0x00;
 	lcd->buffer[2] = reg & 0x7f;
 	index_xfer.tx_buf = lcd->buffer;
 	spi_message_add_tail(&index_xfer, &msg);

 	/* register value */
 	lcd->buffer[4] = LTV_OPC_DATA;
 	lcd->buffer[5] = val >> 8;
 	lcd->buffer[6] = val;
 	value_xfer.tx_buf = lcd->buffer + 4;
 	spi_message_add_tail(&value_xfer, &msg);

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

 /* The comments are taken straight from the data sheet */
 static int ltv350qv_power_on(struct ltv350qv *lcd)
 {
 	int ret;

 	/* Power On Reset Display off State */
 	if (ltv350qv_write_reg(lcd, LTV_PWRCTL1, 0x0000))
 		goto err;
 	usleep_range(15000, 16000);

 	/* Power Setting Function 1 */
 	if (ltv350qv_write_reg(lcd, LTV_PWRCTL1, LTV_VCOM_DISABLE))
 		goto err;
 	if (ltv350qv_write_reg(lcd, LTV_PWRCTL2, LTV_VCOML_ENABLE))
 		goto err_power1;

 	/* Power Setting Function 2 */
 	if (ltv350qv_write_reg(lcd, LTV_PWRCTL1,
 			       LTV_VCOM_DISABLE | LTV_DRIVE_CURRENT(5)
 			       | LTV_SUPPLY_CURRENT(5)))
 		goto err_power2;

 	msleep(55);

 	/* Instruction Setting */
 	ret = ltv350qv_write_reg(lcd, LTV_IFCTL,
 				 LTV_NMD | LTV_REV | LTV_NL(0x1d));
 	ret |= ltv350qv_write_reg(lcd, LTV_DATACTL,
 				  LTV_DS_SAME | LTV_CHS_480
 				  | LTV_DF_RGB | LTV_RGB_BGR);
 	ret |= ltv350qv_write_reg(lcd, LTV_ENTRY_MODE,
 				  LTV_VSPL_ACTIVE_LOW
 				  | LTV_HSPL_ACTIVE_LOW
 				  | LTV_DPL_SAMPLE_RISING
 				  | LTV_EPL_ACTIVE_LOW
 				  | LTV_SS_RIGHT_TO_LEFT);
 	ret |= ltv350qv_write_reg(lcd, LTV_GATECTL1, LTV_CLW(3));
 	ret |= ltv350qv_write_reg(lcd, LTV_GATECTL2,
 				  LTV_NW_INV_1LINE | LTV_FWI(3));
 	ret |= ltv350qv_write_reg(lcd, LTV_VBP, 0x000a);
 	ret |= ltv350qv_write_reg(lcd, LTV_HBP, 0x0021);
 	ret |= ltv350qv_write_reg(lcd, LTV_SOTCTL, LTV_SDT(3) | LTV_EQ(0));
 	ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(0), 0x0103);
 	ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(1), 0x0301);
 	ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(2), 0x1f0f);
 	ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(3), 0x1f0f);
 	ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(4), 0x0707);
 	ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(5), 0x0307);
 	ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(6), 0x0707);
 	ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(7), 0x0000);
 	ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(8), 0x0004);
 	ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(9), 0x0000);
 	if (ret)
 		goto err_settings;

 	/* Wait more than 2 frames */
 	msleep(20);

 	/* Display On Sequence */
 	ret = ltv350qv_write_reg(lcd, LTV_PWRCTL1,
 				 LTV_VCOM_DISABLE | LTV_VCOMOUT_ENABLE
 				 | LTV_POWER_ON | LTV_DRIVE_CURRENT(5)
 				 | LTV_SUPPLY_CURRENT(5));
 	ret |= ltv350qv_write_reg(lcd, LTV_GATECTL2,
 				  LTV_NW_INV_1LINE | LTV_DSC | LTV_FWI(3));
 	if (ret)
 		goto err_disp_on;

 	/* Display should now be ON. Phew. */
 	return 0;

 err_disp_on:
 	/*
 	 * Try to recover. Error handling probably isn't very useful
 	 * at this point, just make a best effort to switch the panel
 	 * off.
 	 */
 	ltv350qv_write_reg(lcd, LTV_PWRCTL1,
 			   LTV_VCOM_DISABLE | LTV_DRIVE_CURRENT(5)
 			   | LTV_SUPPLY_CURRENT(5));
 	ltv350qv_write_reg(lcd, LTV_GATECTL2,
 			   LTV_NW_INV_1LINE | LTV_FWI(3));
 err_settings:
 err_power2:
 err_power1:
 	ltv350qv_write_reg(lcd, LTV_PWRCTL2, 0x0000);
 	usleep_range(1000, 1100);
 err:
 	ltv350qv_write_reg(lcd, LTV_PWRCTL1, LTV_VCOM_DISABLE);
 	return -EIO;
 }

 static int ltv350qv_power_off(struct ltv350qv *lcd)
 {
 	int ret;

 	/* Display Off Sequence */
 	ret = ltv350qv_write_reg(lcd, LTV_PWRCTL1,
 				 LTV_VCOM_DISABLE
 				 | LTV_DRIVE_CURRENT(5)
 				 | LTV_SUPPLY_CURRENT(5));
 	ret |= ltv350qv_write_reg(lcd, LTV_GATECTL2,
 				  LTV_NW_INV_1LINE | LTV_FWI(3));

 	/* Power down setting 1 */
 	ret |= ltv350qv_write_reg(lcd, LTV_PWRCTL2, 0x0000);

 	/* Wait at least 1 ms */
 	usleep_range(1000, 1100);

 	/* Power down setting 2 */
 	ret |= ltv350qv_write_reg(lcd, LTV_PWRCTL1, LTV_VCOM_DISABLE);

 	/*
 	 * No point in trying to recover here. If we can't switch the
 	 * panel off, what are we supposed to do other than inform the
 	 * user about the failure?
 	 */
 	if (ret)
 		return -EIO;

 	/* Display power should now be OFF */
 	return 0;
 }

 static int ltv350qv_power(struct ltv350qv *lcd, int power)
 {
 	int ret = 0;

 	if (POWER_IS_ON(power) && !POWER_IS_ON(lcd->power))
 		ret = ltv350qv_power_on(lcd);
 	else if (!POWER_IS_ON(power) && POWER_IS_ON(lcd->power))
 		ret = ltv350qv_power_off(lcd);

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

 	return ret;
 }

 static int ltv350qv_set_power(struct lcd_device *ld, int power)
 {
 	struct ltv350qv *lcd = lcd_get_data(ld);

 	return ltv350qv_power(lcd, power);
 }

 static int ltv350qv_get_power(struct lcd_device *ld)
 {
 	struct ltv350qv *lcd = lcd_get_data(ld);

 	return lcd->power;
 }

 static const struct lcd_ops ltv_ops = {
 	.get_power	= ltv350qv_get_power,
 	.set_power	= ltv350qv_set_power,
 };

 static int ltv350qv_probe(struct spi_device *spi)
 {
 	struct ltv350qv *lcd;
 	struct lcd_device *ld;
 	int ret;

 	lcd = devm_kzalloc(&spi->dev, sizeof(struct ltv350qv), GFP_KERNEL);
 	if (!lcd)
 		return -ENOMEM;

 	lcd->spi = spi;
 	lcd->power = FB_BLANK_POWERDOWN;
 	lcd->buffer = devm_kzalloc(&spi->dev, 8, GFP_KERNEL);
 	if (!lcd->buffer)
 		return -ENOMEM;

 	ld = devm_lcd_device_register(&spi->dev, "ltv350qv", &spi->dev, lcd,
 					&ltv_ops);
 	if (IS_ERR(ld))
 		return PTR_ERR(ld);

 	lcd->ld = ld;

 	ret = ltv350qv_power(lcd, FB_BLANK_UNBLANK);
 	if (ret)
 		return ret;

 	spi_set_drvdata(spi, lcd);

 	return 0;
 }

 static void ltv350qv_remove(struct spi_device *spi)
 {
 	struct ltv350qv *lcd = spi_get_drvdata(spi);

 	ltv350qv_power(lcd, FB_BLANK_POWERDOWN);
 }

 #ifdef CONFIG_PM_SLEEP
 static int ltv350qv_suspend(struct device *dev)
 {
 	struct ltv350qv *lcd = dev_get_drvdata(dev);

 	return ltv350qv_power(lcd, FB_BLANK_POWERDOWN);
 }

 static int ltv350qv_resume(struct device *dev)
 {
 	struct ltv350qv *lcd = dev_get_drvdata(dev);

 	return ltv350qv_power(lcd, FB_BLANK_UNBLANK);
 }
 #endif

 static SIMPLE_DEV_PM_OPS(ltv350qv_pm_ops, ltv350qv_suspend, ltv350qv_resume);

 /* Power down all displays on reboot, poweroff or halt */
 static void ltv350qv_shutdown(struct spi_device *spi)
 {
 	struct ltv350qv *lcd = spi_get_drvdata(spi);

 	ltv350qv_power(lcd, FB_BLANK_POWERDOWN);
 }

 static struct spi_driver ltv350qv_driver = {
 	.driver = {
 		.name		= "ltv350qv",
 		.pm		= &ltv350qv_pm_ops,
 	},

 	.probe		= ltv350qv_probe,
 	.remove		= ltv350qv_remove,
 	.shutdown	= ltv350qv_shutdown,
 };

 module_spi_driver(ltv350qv_driver);

 MODULE_AUTHOR("Haavard Skinnemoen (Atmel)");
 MODULE_DESCRIPTION("Samsung LTV350QV LCD Driver");
 MODULE_LICENSE("GPL");
 MODULE_ALIAS("spi:ltv350qv");
	// SPDX-License-Identifier: GPL-2.0-only
	/*
	* Power control for Samsung LTV350QV Quarter VGA LCD Panel
	*
	* Copyright (C) 2006, 2007 Atmel Corporation
	*/
	#include <linux/delay.h>
	#include <linux/err.h>
	#include <linux/fb.h>
	#include <linux/init.h>
	#include <linux/lcd.h>
	#include <linux/module.h>
	#include <linux/slab.h>
	#include <linux/spi/spi.h>

	#include "ltv350qv.h"

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

	struct ltv350qv {
	struct spi_device *spi;
	u8 *buffer;
	int power;
	struct lcd_device *ld;
	};

	/*
	* The power-on and power-off sequences are taken from the
	* LTV350QV-F04 data sheet from Samsung. The register definitions are
	* taken from the S6F2002 command list also from Samsung.
	*
	* There's still some voodoo going on here, but it's a lot better than
	* in the first incarnation of the driver where all we had was the raw
	* numbers from the initialization sequence.
	*/
	static int ltv350qv_write_reg(struct ltv350qv *lcd, u8 reg, u16 val)
	{
	struct spi_message msg;
	struct spi_transfer index_xfer = {
	.len = 3,
	.cs_change = 1,
	};
	struct spi_transfer value_xfer = {
	.len = 3,
	};

	spi_message_init(&msg);

	/* register index */
	lcd->buffer[0] = LTV_OPC_INDEX;
	lcd->buffer[1] = 0x00;
	lcd->buffer[2] = reg & 0x7f;
	index_xfer.tx_buf = lcd->buffer;
	spi_message_add_tail(&index_xfer, &msg);

	/* register value */
	lcd->buffer[4] = LTV_OPC_DATA;
	lcd->buffer[5] = val >> 8;
	lcd->buffer[6] = val;
	value_xfer.tx_buf = lcd->buffer + 4;
	spi_message_add_tail(&value_xfer, &msg);

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

	/* The comments are taken straight from the data sheet */
	static int ltv350qv_power_on(struct ltv350qv *lcd)
	{
	int ret;

	/* Power On Reset Display off State */
	if (ltv350qv_write_reg(lcd, LTV_PWRCTL1, 0x0000))
	goto err;
	usleep_range(15000, 16000);

	/* Power Setting Function 1 */
	if (ltv350qv_write_reg(lcd, LTV_PWRCTL1, LTV_VCOM_DISABLE))
	goto err;
	if (ltv350qv_write_reg(lcd, LTV_PWRCTL2, LTV_VCOML_ENABLE))
	goto err_power1;

	/* Power Setting Function 2 */
	if (ltv350qv_write_reg(lcd, LTV_PWRCTL1,
	LTV_VCOM_DISABLE \| LTV_DRIVE_CURRENT(5)
	\| LTV_SUPPLY_CURRENT(5)))
	goto err_power2;

	msleep(55);

	/* Instruction Setting */
	ret = ltv350qv_write_reg(lcd, LTV_IFCTL,
	LTV_NMD \| LTV_REV \| LTV_NL(0x1d));
	ret \|= ltv350qv_write_reg(lcd, LTV_DATACTL,
	LTV_DS_SAME \| LTV_CHS_480
	\| LTV_DF_RGB \| LTV_RGB_BGR);
	ret \|= ltv350qv_write_reg(lcd, LTV_ENTRY_MODE,
	LTV_VSPL_ACTIVE_LOW
	\| LTV_HSPL_ACTIVE_LOW
	\| LTV_DPL_SAMPLE_RISING
	\| LTV_EPL_ACTIVE_LOW
	\| LTV_SS_RIGHT_TO_LEFT);
	ret \|= ltv350qv_write_reg(lcd, LTV_GATECTL1, LTV_CLW(3));
	ret \|= ltv350qv_write_reg(lcd, LTV_GATECTL2,
	LTV_NW_INV_1LINE \| LTV_FWI(3));
	ret \|= ltv350qv_write_reg(lcd, LTV_VBP, 0x000a);
	ret \|= ltv350qv_write_reg(lcd, LTV_HBP, 0x0021);
	ret \|= ltv350qv_write_reg(lcd, LTV_SOTCTL, LTV_SDT(3) \| LTV_EQ(0));
	ret \|= ltv350qv_write_reg(lcd, LTV_GAMMA(0), 0x0103);
	ret \|= ltv350qv_write_reg(lcd, LTV_GAMMA(1), 0x0301);
	ret \|= ltv350qv_write_reg(lcd, LTV_GAMMA(2), 0x1f0f);
	ret \|= ltv350qv_write_reg(lcd, LTV_GAMMA(3), 0x1f0f);
	ret \|= ltv350qv_write_reg(lcd, LTV_GAMMA(4), 0x0707);
	ret \|= ltv350qv_write_reg(lcd, LTV_GAMMA(5), 0x0307);
	ret \|= ltv350qv_write_reg(lcd, LTV_GAMMA(6), 0x0707);
	ret \|= ltv350qv_write_reg(lcd, LTV_GAMMA(7), 0x0000);
	ret \|= ltv350qv_write_reg(lcd, LTV_GAMMA(8), 0x0004);
	ret \|= ltv350qv_write_reg(lcd, LTV_GAMMA(9), 0x0000);
	if (ret)
	goto err_settings;

	/* Wait more than 2 frames */
	msleep(20);

	/* Display On Sequence */
	ret = ltv350qv_write_reg(lcd, LTV_PWRCTL1,
	LTV_VCOM_DISABLE \| LTV_VCOMOUT_ENABLE
	\| LTV_POWER_ON \| LTV_DRIVE_CURRENT(5)
	\| LTV_SUPPLY_CURRENT(5));
	ret \|= ltv350qv_write_reg(lcd, LTV_GATECTL2,
	LTV_NW_INV_1LINE \| LTV_DSC \| LTV_FWI(3));
	if (ret)
	goto err_disp_on;

	/* Display should now be ON. Phew. */
	return 0;

	err_disp_on:
	/*
	* Try to recover. Error handling probably isn't very useful
	* at this point, just make a best effort to switch the panel
	* off.
	*/
	ltv350qv_write_reg(lcd, LTV_PWRCTL1,
	LTV_VCOM_DISABLE \| LTV_DRIVE_CURRENT(5)
	\| LTV_SUPPLY_CURRENT(5));
	ltv350qv_write_reg(lcd, LTV_GATECTL2,
	LTV_NW_INV_1LINE \| LTV_FWI(3));
	err_settings:
	err_power2:
	err_power1:
	ltv350qv_write_reg(lcd, LTV_PWRCTL2, 0x0000);
	usleep_range(1000, 1100);
	err:
	ltv350qv_write_reg(lcd, LTV_PWRCTL1, LTV_VCOM_DISABLE);
	return -EIO;
	}

	static int ltv350qv_power_off(struct ltv350qv *lcd)
	{
	int ret;

	/* Display Off Sequence */
	ret = ltv350qv_write_reg(lcd, LTV_PWRCTL1,
	LTV_VCOM_DISABLE
	\| LTV_DRIVE_CURRENT(5)
	\| LTV_SUPPLY_CURRENT(5));
	ret \|= ltv350qv_write_reg(lcd, LTV_GATECTL2,
	LTV_NW_INV_1LINE \| LTV_FWI(3));

	/* Power down setting 1 */
	ret \|= ltv350qv_write_reg(lcd, LTV_PWRCTL2, 0x0000);

	/* Wait at least 1 ms */
	usleep_range(1000, 1100);

	/* Power down setting 2 */
	ret \|= ltv350qv_write_reg(lcd, LTV_PWRCTL1, LTV_VCOM_DISABLE);

	/*
	* No point in trying to recover here. If we can't switch the
	* panel off, what are we supposed to do other than inform the
	* user about the failure?
	*/
	if (ret)
	return -EIO;

	/* Display power should now be OFF */
	return 0;
	}

	static int ltv350qv_power(struct ltv350qv *lcd, int power)
	{
	int ret = 0;

	if (POWER_IS_ON(power) && !POWER_IS_ON(lcd->power))
	ret = ltv350qv_power_on(lcd);
	else if (!POWER_IS_ON(power) && POWER_IS_ON(lcd->power))
	ret = ltv350qv_power_off(lcd);

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

	return ret;
	}

	static int ltv350qv_set_power(struct lcd_device *ld, int power)
	{
	struct ltv350qv *lcd = lcd_get_data(ld);

	return ltv350qv_power(lcd, power);
	}

	static int ltv350qv_get_power(struct lcd_device *ld)
	{
	struct ltv350qv *lcd = lcd_get_data(ld);

	return lcd->power;
	}

	static const struct lcd_ops ltv_ops = {
	.get_power = ltv350qv_get_power,
	.set_power = ltv350qv_set_power,
	};

	static int ltv350qv_probe(struct spi_device *spi)
	{
	struct ltv350qv *lcd;
	struct lcd_device *ld;
	int ret;

	lcd = devm_kzalloc(&spi->dev, sizeof(struct ltv350qv), GFP_KERNEL);
	if (!lcd)
	return -ENOMEM;

	lcd->spi = spi;
	lcd->power = FB_BLANK_POWERDOWN;
	lcd->buffer = devm_kzalloc(&spi->dev, 8, GFP_KERNEL);
	if (!lcd->buffer)
	return -ENOMEM;

	ld = devm_lcd_device_register(&spi->dev, "ltv350qv", &spi->dev, lcd,
	&ltv_ops);
	if (IS_ERR(ld))
	return PTR_ERR(ld);

	lcd->ld = ld;

	ret = ltv350qv_power(lcd, FB_BLANK_UNBLANK);
	if (ret)
	return ret;

	spi_set_drvdata(spi, lcd);

	return 0;
	}

	static void ltv350qv_remove(struct spi_device *spi)
	{
	struct ltv350qv *lcd = spi_get_drvdata(spi);

	ltv350qv_power(lcd, FB_BLANK_POWERDOWN);
	}

	#ifdef CONFIG_PM_SLEEP
	static int ltv350qv_suspend(struct device *dev)
	{
	struct ltv350qv *lcd = dev_get_drvdata(dev);

	return ltv350qv_power(lcd, FB_BLANK_POWERDOWN);
	}

	static int ltv350qv_resume(struct device *dev)
	{
	struct ltv350qv *lcd = dev_get_drvdata(dev);

	return ltv350qv_power(lcd, FB_BLANK_UNBLANK);
	}
	#endif

	static SIMPLE_DEV_PM_OPS(ltv350qv_pm_ops, ltv350qv_suspend, ltv350qv_resume);

	/* Power down all displays on reboot, poweroff or halt */
	static void ltv350qv_shutdown(struct spi_device *spi)
	{
	struct ltv350qv *lcd = spi_get_drvdata(spi);

	ltv350qv_power(lcd, FB_BLANK_POWERDOWN);
	}

	static struct spi_driver ltv350qv_driver = {
	.driver = {
	.name = "ltv350qv",
	.pm = &ltv350qv_pm_ops,
	},

	.probe = ltv350qv_probe,
	.remove = ltv350qv_remove,
	.shutdown = ltv350qv_shutdown,
	};

	module_spi_driver(ltv350qv_driver);

	MODULE_AUTHOR("Haavard Skinnemoen (Atmel)");
	MODULE_DESCRIPTION("Samsung LTV350QV LCD Driver");
	MODULE_LICENSE("GPL");
	MODULE_ALIAS("spi:ltv350qv");