drivers/video/backlight/tps65217_bl.c - linux - Git at Google

 /*
  * tps65217_bl.c
  *
  * TPS65217 backlight driver
  *
  * Copyright (C) 2012 Matthias Kaehlcke
  * Author: Matthias Kaehlcke <matthias@kaehlcke.net>
  *
  * 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 version 2.
  *
  * This program is distributed "as is" WITHOUT ANY WARRANTY of any
  * kind, whether express or implied; without even the implied warranty
  * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  */

 #include <linux/kernel.h>
 #include <linux/backlight.h>
 #include <linux/err.h>
 #include <linux/fb.h>
 #include <linux/mfd/tps65217.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>
 #include <linux/slab.h>

 struct tps65217_bl {
 	struct tps65217 *tps;
 	struct device *dev;
 	struct backlight_device *bl;
 	bool is_enabled;
 };

 static int tps65217_bl_enable(struct tps65217_bl *tps65217_bl)
 {
 	int rc;

 	rc = tps65217_set_bits(tps65217_bl->tps, TPS65217_REG_WLEDCTRL1,
 			TPS65217_WLEDCTRL1_ISINK_ENABLE,
 			TPS65217_WLEDCTRL1_ISINK_ENABLE, TPS65217_PROTECT_NONE);
 	if (rc) {
 		dev_err(tps65217_bl->dev,
 			"failed to enable backlight: %d\n", rc);
 		return rc;
 	}

 	tps65217_bl->is_enabled = true;

 	dev_dbg(tps65217_bl->dev, "backlight enabled\n");

 	return 0;
 }

 static int tps65217_bl_disable(struct tps65217_bl *tps65217_bl)
 {
 	int rc;

 	rc = tps65217_clear_bits(tps65217_bl->tps,
 				TPS65217_REG_WLEDCTRL1,
 				TPS65217_WLEDCTRL1_ISINK_ENABLE,
 				TPS65217_PROTECT_NONE);
 	if (rc) {
 		dev_err(tps65217_bl->dev,
 			"failed to disable backlight: %d\n", rc);
 		return rc;
 	}

 	tps65217_bl->is_enabled = false;

 	dev_dbg(tps65217_bl->dev, "backlight disabled\n");

 	return 0;
 }

 static int tps65217_bl_update_status(struct backlight_device *bl)
 {
 	struct tps65217_bl *tps65217_bl = bl_get_data(bl);
 	int rc;
 	int brightness = bl->props.brightness;

 	if (bl->props.state & BL_CORE_SUSPENDED)
 		brightness = 0;

 	if ((bl->props.power != FB_BLANK_UNBLANK) ||
 		(bl->props.fb_blank != FB_BLANK_UNBLANK))
 		/* framebuffer in low power mode or blanking active */
 		brightness = 0;

 	if (brightness > 0) {
 		rc = tps65217_reg_write(tps65217_bl->tps,
 					TPS65217_REG_WLEDCTRL2,
 					brightness - 1,
 					TPS65217_PROTECT_NONE);
 		if (rc) {
 			dev_err(tps65217_bl->dev,
 				"failed to set brightness level: %d\n", rc);
 			return rc;
 		}

 		dev_dbg(tps65217_bl->dev, "brightness set to %d\n", brightness);

 		if (!tps65217_bl->is_enabled)
 			rc = tps65217_bl_enable(tps65217_bl);
 	} else {
 		rc = tps65217_bl_disable(tps65217_bl);
 	}

 	return rc;
 }

 static const struct backlight_ops tps65217_bl_ops = {
 	.options	= BL_CORE_SUSPENDRESUME,
 	.update_status	= tps65217_bl_update_status,
 };

 static int tps65217_bl_hw_init(struct tps65217_bl *tps65217_bl,
 			struct tps65217_bl_pdata *pdata)
 {
 	int rc;

 	rc = tps65217_bl_disable(tps65217_bl);
 	if (rc)
 		return rc;

 	switch (pdata->isel) {
 	case TPS65217_BL_ISET1:
 		/* select ISET_1 current level */
 		rc = tps65217_clear_bits(tps65217_bl->tps,
 					TPS65217_REG_WLEDCTRL1,
 					TPS65217_WLEDCTRL1_ISEL,
 					TPS65217_PROTECT_NONE);
 		if (rc) {
 			dev_err(tps65217_bl->dev,
 				"failed to select ISET1 current level: %d)\n",
 				rc);
 			return rc;
 		}

 		dev_dbg(tps65217_bl->dev, "selected ISET1 current level\n");

 		break;

 	case TPS65217_BL_ISET2:
 		/* select ISET2 current level */
 		rc = tps65217_set_bits(tps65217_bl->tps, TPS65217_REG_WLEDCTRL1,
 				TPS65217_WLEDCTRL1_ISEL,
 				TPS65217_WLEDCTRL1_ISEL, TPS65217_PROTECT_NONE);
 		if (rc) {
 			dev_err(tps65217_bl->dev,
 				"failed to select ISET2 current level: %d\n",
 				rc);
 			return rc;
 		}

 		dev_dbg(tps65217_bl->dev, "selected ISET2 current level\n");

 		break;

 	default:
 		dev_err(tps65217_bl->dev,
 			"invalid value for current level: %d\n", pdata->isel);
 		return -EINVAL;
 	}

 	/* set PWM frequency */
 	rc = tps65217_set_bits(tps65217_bl->tps,
 			TPS65217_REG_WLEDCTRL1,
 			TPS65217_WLEDCTRL1_FDIM_MASK,
 			pdata->fdim,
 			TPS65217_PROTECT_NONE);
 	if (rc) {
 		dev_err(tps65217_bl->dev,
 			"failed to select PWM dimming frequency: %d\n",
 			rc);
 		return rc;
 	}

 	return 0;
 }

 #ifdef CONFIG_OF
 static struct tps65217_bl_pdata *
 tps65217_bl_parse_dt(struct platform_device *pdev)
 {
 	struct tps65217 *tps = dev_get_drvdata(pdev->dev.parent);
 	struct device_node *node;
 	struct tps65217_bl_pdata *pdata, *err;
 	u32 val;

 	node = of_get_child_by_name(tps->dev->of_node, "backlight");
 	if (!node)
 		return ERR_PTR(-ENODEV);

 	pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
 	if (!pdata) {
 		err = ERR_PTR(-ENOMEM);
 		goto err;
 	}

 	pdata->isel = TPS65217_BL_ISET1;
 	if (!of_property_read_u32(node, "isel", &val)) {
 		if (val < TPS65217_BL_ISET1 ||
 			val > TPS65217_BL_ISET2) {
 			dev_err(&pdev->dev,
 				"invalid 'isel' value in the device tree\n");
 			err = ERR_PTR(-EINVAL);
 			goto err;
 		}

 		pdata->isel = val;
 	}

 	pdata->fdim = TPS65217_BL_FDIM_200HZ;
 	if (!of_property_read_u32(node, "fdim", &val)) {
 		switch (val) {
 		case 100:
 			pdata->fdim = TPS65217_BL_FDIM_100HZ;
 			break;

 		case 200:
 			pdata->fdim = TPS65217_BL_FDIM_200HZ;
 			break;

 		case 500:
 			pdata->fdim = TPS65217_BL_FDIM_500HZ;
 			break;

 		case 1000:
 			pdata->fdim = TPS65217_BL_FDIM_1000HZ;
 			break;

 		default:
 			dev_err(&pdev->dev,
 				"invalid 'fdim' value in the device tree\n");
 			err = ERR_PTR(-EINVAL);
 			goto err;
 		}
 	}

 	if (!of_property_read_u32(node, "default-brightness", &val)) {
 		if (val > 100) {
 			dev_err(&pdev->dev,
 				"invalid 'default-brightness' value in the device tree\n");
 			err = ERR_PTR(-EINVAL);
 			goto err;
 		}

 		pdata->dft_brightness = val;
 	}

 	of_node_put(node);

 	return pdata;

 err:
 	of_node_put(node);

 	return err;
 }
 #else
 static struct tps65217_bl_pdata *
 tps65217_bl_parse_dt(struct platform_device *pdev)
 {
 	return NULL;
 }
 #endif

 static int tps65217_bl_probe(struct platform_device *pdev)
 {
 	int rc;
 	struct tps65217 *tps = dev_get_drvdata(pdev->dev.parent);
 	struct tps65217_bl *tps65217_bl;
 	struct tps65217_bl_pdata *pdata;
 	struct backlight_properties bl_props;

 	pdata = tps65217_bl_parse_dt(pdev);
 	if (IS_ERR(pdata))
 		return PTR_ERR(pdata);

 	tps65217_bl = devm_kzalloc(&pdev->dev, sizeof(*tps65217_bl),
 				GFP_KERNEL);
 	if (tps65217_bl == NULL)
 		return -ENOMEM;

 	tps65217_bl->tps = tps;
 	tps65217_bl->dev = &pdev->dev;
 	tps65217_bl->is_enabled = false;

 	rc = tps65217_bl_hw_init(tps65217_bl, pdata);
 	if (rc)
 		return rc;

 	memset(&bl_props, 0, sizeof(struct backlight_properties));
 	bl_props.type = BACKLIGHT_RAW;
 	bl_props.max_brightness = 100;

 	tps65217_bl->bl = devm_backlight_device_register(&pdev->dev, pdev->name,
 						tps65217_bl->dev, tps65217_bl,
 						&tps65217_bl_ops, &bl_props);
 	if (IS_ERR(tps65217_bl->bl)) {
 		dev_err(tps65217_bl->dev,
 			"registration of backlight device failed: %d\n", rc);
 		return PTR_ERR(tps65217_bl->bl);
 	}

 	tps65217_bl->bl->props.brightness = pdata->dft_brightness;
 	backlight_update_status(tps65217_bl->bl);
 	platform_set_drvdata(pdev, tps65217_bl);

 	return 0;
 }

 #ifdef CONFIG_OF
 static const struct of_device_id tps65217_bl_of_match[] = {
 	{ .compatible = "ti,tps65217-bl", },
 	{ /* sentinel */ },
 };
 MODULE_DEVICE_TABLE(of, tps65217_bl_of_match);
 #endif

 static struct platform_driver tps65217_bl_driver = {
 	.probe		= tps65217_bl_probe,
 	.driver		= {
 		.name	= "tps65217-bl",
 		.of_match_table = of_match_ptr(tps65217_bl_of_match),
 	},
 };

 module_platform_driver(tps65217_bl_driver);

 MODULE_DESCRIPTION("TPS65217 Backlight driver");
 MODULE_LICENSE("GPL v2");
 MODULE_AUTHOR("Matthias Kaehlcke <matthias@kaehlcke.net>");
	/*
	* tps65217_bl.c
	*
	* TPS65217 backlight driver
	*
	* Copyright (C) 2012 Matthias Kaehlcke
	* Author: Matthias Kaehlcke <matthias@kaehlcke.net>
	*
	* 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 version 2.
	*
	* This program is distributed "as is" WITHOUT ANY WARRANTY of any
	* kind, whether express or implied; without even the implied warranty
	* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*/

	#include <linux/kernel.h>
	#include <linux/backlight.h>
	#include <linux/err.h>
	#include <linux/fb.h>
	#include <linux/mfd/tps65217.h>
	#include <linux/module.h>
	#include <linux/platform_device.h>
	#include <linux/slab.h>

	struct tps65217_bl {
	struct tps65217 *tps;
	struct device *dev;
	struct backlight_device *bl;
	bool is_enabled;
	};

	static int tps65217_bl_enable(struct tps65217_bl *tps65217_bl)
	{
	int rc;

	rc = tps65217_set_bits(tps65217_bl->tps, TPS65217_REG_WLEDCTRL1,
	TPS65217_WLEDCTRL1_ISINK_ENABLE,
	TPS65217_WLEDCTRL1_ISINK_ENABLE, TPS65217_PROTECT_NONE);
	if (rc) {
	dev_err(tps65217_bl->dev,
	"failed to enable backlight: %d\n", rc);
	return rc;
	}

	tps65217_bl->is_enabled = true;

	dev_dbg(tps65217_bl->dev, "backlight enabled\n");

	return 0;
	}

	static int tps65217_bl_disable(struct tps65217_bl *tps65217_bl)
	{
	int rc;

	rc = tps65217_clear_bits(tps65217_bl->tps,
	TPS65217_REG_WLEDCTRL1,
	TPS65217_WLEDCTRL1_ISINK_ENABLE,
	TPS65217_PROTECT_NONE);
	if (rc) {
	dev_err(tps65217_bl->dev,
	"failed to disable backlight: %d\n", rc);
	return rc;
	}

	tps65217_bl->is_enabled = false;

	dev_dbg(tps65217_bl->dev, "backlight disabled\n");

	return 0;
	}

	static int tps65217_bl_update_status(struct backlight_device *bl)
	{
	struct tps65217_bl *tps65217_bl = bl_get_data(bl);
	int rc;
	int brightness = bl->props.brightness;

	if (bl->props.state & BL_CORE_SUSPENDED)
	brightness = 0;

	if ((bl->props.power != FB_BLANK_UNBLANK) \|\|
	(bl->props.fb_blank != FB_BLANK_UNBLANK))
	/* framebuffer in low power mode or blanking active */
	brightness = 0;

	if (brightness > 0) {
	rc = tps65217_reg_write(tps65217_bl->tps,
	TPS65217_REG_WLEDCTRL2,
	brightness - 1,
	TPS65217_PROTECT_NONE);
	if (rc) {
	dev_err(tps65217_bl->dev,
	"failed to set brightness level: %d\n", rc);
	return rc;
	}

	dev_dbg(tps65217_bl->dev, "brightness set to %d\n", brightness);

	if (!tps65217_bl->is_enabled)
	rc = tps65217_bl_enable(tps65217_bl);
	} else {
	rc = tps65217_bl_disable(tps65217_bl);
	}

	return rc;
	}

	static const struct backlight_ops tps65217_bl_ops = {
	.options = BL_CORE_SUSPENDRESUME,
	.update_status = tps65217_bl_update_status,
	};

	static int tps65217_bl_hw_init(struct tps65217_bl *tps65217_bl,
	struct tps65217_bl_pdata *pdata)
	{
	int rc;

	rc = tps65217_bl_disable(tps65217_bl);
	if (rc)
	return rc;

	switch (pdata->isel) {
	case TPS65217_BL_ISET1:
	/* select ISET_1 current level */
	rc = tps65217_clear_bits(tps65217_bl->tps,
	TPS65217_REG_WLEDCTRL1,
	TPS65217_WLEDCTRL1_ISEL,
	TPS65217_PROTECT_NONE);
	if (rc) {
	dev_err(tps65217_bl->dev,
	"failed to select ISET1 current level: %d)\n",
	rc);
	return rc;
	}

	dev_dbg(tps65217_bl->dev, "selected ISET1 current level\n");

	break;

	case TPS65217_BL_ISET2:
	/* select ISET2 current level */
	rc = tps65217_set_bits(tps65217_bl->tps, TPS65217_REG_WLEDCTRL1,
	TPS65217_WLEDCTRL1_ISEL,
	TPS65217_WLEDCTRL1_ISEL, TPS65217_PROTECT_NONE);
	if (rc) {
	dev_err(tps65217_bl->dev,
	"failed to select ISET2 current level: %d\n",
	rc);
	return rc;
	}

	dev_dbg(tps65217_bl->dev, "selected ISET2 current level\n");

	break;

	default:
	dev_err(tps65217_bl->dev,
	"invalid value for current level: %d\n", pdata->isel);
	return -EINVAL;
	}

	/* set PWM frequency */
	rc = tps65217_set_bits(tps65217_bl->tps,
	TPS65217_REG_WLEDCTRL1,
	TPS65217_WLEDCTRL1_FDIM_MASK,
	pdata->fdim,
	TPS65217_PROTECT_NONE);
	if (rc) {
	dev_err(tps65217_bl->dev,
	"failed to select PWM dimming frequency: %d\n",
	rc);
	return rc;
	}

	return 0;
	}

	#ifdef CONFIG_OF
	static struct tps65217_bl_pdata *
	tps65217_bl_parse_dt(struct platform_device *pdev)
	{
	struct tps65217 *tps = dev_get_drvdata(pdev->dev.parent);
	struct device_node *node;
	struct tps65217_bl_pdata pdata, err;
	u32 val;

	node = of_get_child_by_name(tps->dev->of_node, "backlight");
	if (!node)
	return ERR_PTR(-ENODEV);

	pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
	if (!pdata) {
	err = ERR_PTR(-ENOMEM);
	goto err;
	}

	pdata->isel = TPS65217_BL_ISET1;
	if (!of_property_read_u32(node, "isel", &val)) {
	if (val < TPS65217_BL_ISET1 \|\|
	val > TPS65217_BL_ISET2) {
	dev_err(&pdev->dev,
	"invalid 'isel' value in the device tree\n");
	err = ERR_PTR(-EINVAL);
	goto err;
	}

	pdata->isel = val;
	}

	pdata->fdim = TPS65217_BL_FDIM_200HZ;
	if (!of_property_read_u32(node, "fdim", &val)) {
	switch (val) {
	case 100:
	pdata->fdim = TPS65217_BL_FDIM_100HZ;
	break;

	case 200:
	pdata->fdim = TPS65217_BL_FDIM_200HZ;
	break;

	case 500:
	pdata->fdim = TPS65217_BL_FDIM_500HZ;
	break;

	case 1000:
	pdata->fdim = TPS65217_BL_FDIM_1000HZ;
	break;

	default:
	dev_err(&pdev->dev,
	"invalid 'fdim' value in the device tree\n");
	err = ERR_PTR(-EINVAL);
	goto err;
	}
	}

	if (!of_property_read_u32(node, "default-brightness", &val)) {
	if (val > 100) {
	dev_err(&pdev->dev,
	"invalid 'default-brightness' value in the device tree\n");
	err = ERR_PTR(-EINVAL);
	goto err;
	}

	pdata->dft_brightness = val;
	}

	of_node_put(node);

	return pdata;

	err:
	of_node_put(node);

	return err;
	}
	#else
	static struct tps65217_bl_pdata *
	tps65217_bl_parse_dt(struct platform_device *pdev)
	{
	return NULL;
	}
	#endif

	static int tps65217_bl_probe(struct platform_device *pdev)
	{
	int rc;
	struct tps65217 *tps = dev_get_drvdata(pdev->dev.parent);
	struct tps65217_bl *tps65217_bl;
	struct tps65217_bl_pdata *pdata;
	struct backlight_properties bl_props;

	pdata = tps65217_bl_parse_dt(pdev);
	if (IS_ERR(pdata))
	return PTR_ERR(pdata);

	tps65217_bl = devm_kzalloc(&pdev->dev, sizeof(*tps65217_bl),
	GFP_KERNEL);
	if (tps65217_bl == NULL)
	return -ENOMEM;

	tps65217_bl->tps = tps;
	tps65217_bl->dev = &pdev->dev;
	tps65217_bl->is_enabled = false;

	rc = tps65217_bl_hw_init(tps65217_bl, pdata);
	if (rc)
	return rc;

	memset(&bl_props, 0, sizeof(struct backlight_properties));
	bl_props.type = BACKLIGHT_RAW;
	bl_props.max_brightness = 100;

	tps65217_bl->bl = devm_backlight_device_register(&pdev->dev, pdev->name,
	tps65217_bl->dev, tps65217_bl,
	&tps65217_bl_ops, &bl_props);
	if (IS_ERR(tps65217_bl->bl)) {
	dev_err(tps65217_bl->dev,
	"registration of backlight device failed: %d\n", rc);
	return PTR_ERR(tps65217_bl->bl);
	}

	tps65217_bl->bl->props.brightness = pdata->dft_brightness;
	backlight_update_status(tps65217_bl->bl);
	platform_set_drvdata(pdev, tps65217_bl);

	return 0;
	}

	#ifdef CONFIG_OF
	static const struct of_device_id tps65217_bl_of_match[] = {
	{ .compatible = "ti,tps65217-bl", },
	{ /* sentinel */ },
	};
	MODULE_DEVICE_TABLE(of, tps65217_bl_of_match);
	#endif

	static struct platform_driver tps65217_bl_driver = {
	.probe = tps65217_bl_probe,
	.driver = {
	.name = "tps65217-bl",
	.of_match_table = of_match_ptr(tps65217_bl_of_match),
	},
	};

	module_platform_driver(tps65217_bl_driver);

	MODULE_DESCRIPTION("TPS65217 Backlight driver");
	MODULE_LICENSE("GPL v2");
	MODULE_AUTHOR("Matthias Kaehlcke <matthias@kaehlcke.net>");