backlight: Add AAT2870 backlight driver (4b0d711b) · Commits · e / devices / android_kernel_fairphone_FP4

drivers/video/backlight/Kconfig

+7 −0

Original line number	Diff line number	Diff line
		@@ -335,6 +335,13 @@ config BACKLIGHT_PCF50633
		If you have a backlight driven by a NXP PCF50633 MFD, say Y here to
		enable its driver.

		config BACKLIGHT_AAT2870
		bool "AnalogicTech AAT2870 Backlight"
		depends on BACKLIGHT_CLASS_DEVICE && MFD_AAT2870_CORE
		help
		If you have a AnalogicTech AAT2870 say Y to enable the
		backlight driver.

		endif # BACKLIGHT_CLASS_DEVICE

		endif # BACKLIGHT_LCD_SUPPORT

drivers/video/backlight/Makefile

+1 −0

Original line number	Diff line number	Diff line
		@@ -38,4 +38,5 @@ obj-$(CONFIG_BACKLIGHT_ADP8860) += adp8860_bl.o
		obj-$(CONFIG_BACKLIGHT_ADP8870) += adp8870_bl.o
		obj-$(CONFIG_BACKLIGHT_88PM860X) += 88pm860x_bl.o
		obj-$(CONFIG_BACKLIGHT_PCF50633) += pcf50633-backlight.o
		obj-$(CONFIG_BACKLIGHT_AAT2870) += aat2870_bl.o

drivers/video/backlight/aat2870_bl.c

0 → 100644

+246 −0

Original line number	Diff line number	Diff line
		/*
		* linux/drivers/video/backlight/aat2870_bl.c
		*
		* Copyright (c) 2011, NVIDIA Corporation.
		* Author: Jin Park <jinyoungp@nvidia.com>
		*
		* This program is free software; you can redistribute it and/or
		* modify it under the terms of the GNU General Public License
		* version 2 as published by the Free Software Foundation.
		*
		* This program is distributed in the hope that it will be useful, but
		* WITHOUT ANY WARRANTY; without even the implied warranty of
		* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
		* General Public License for more details.
		*
		* You should have received a copy of the GNU General Public License
		* along with this program; if not, write to the Free Software
		* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
		* 02110-1301 USA
		*/

		#include <linux/module.h>
		#include <linux/kernel.h>
		#include <linux/init.h>
		#include <linux/platform_device.h>
		#include <linux/mutex.h>
		#include <linux/delay.h>
		#include <linux/fb.h>
		#include <linux/backlight.h>
		#include <linux/mfd/aat2870.h>

		struct aat2870_bl_driver_data {
		struct platform_device *pdev;
		struct backlight_device *bd;

		int channels;
		int max_current;
		int brightness; /* current brightness */
		};

		static inline int aat2870_brightness(struct aat2870_bl_driver_data *aat2870_bl,
		int brightness)
		{
		struct backlight_device *bd = aat2870_bl->bd;
		int val;

		val = brightness * aat2870_bl->max_current;
		val /= bd->props.max_brightness;

		return val;
		}

		static inline int aat2870_bl_enable(struct aat2870_bl_driver_data *aat2870_bl)
		{
		struct aat2870_data *aat2870
		= dev_get_drvdata(aat2870_bl->pdev->dev.parent);

		return aat2870->write(aat2870, AAT2870_BL_CH_EN,
		(u8)aat2870_bl->channels);
		}

		static inline int aat2870_bl_disable(struct aat2870_bl_driver_data *aat2870_bl)
		{
		struct aat2870_data *aat2870
		= dev_get_drvdata(aat2870_bl->pdev->dev.parent);

		return aat2870->write(aat2870, AAT2870_BL_CH_EN, 0x0);
		}

		static int aat2870_bl_get_brightness(struct backlight_device *bd)
		{
		return bd->props.brightness;
		}

		static int aat2870_bl_update_status(struct backlight_device *bd)
		{
		struct aat2870_bl_driver_data *aat2870_bl = dev_get_drvdata(&bd->dev);
		struct aat2870_data *aat2870 =
		dev_get_drvdata(aat2870_bl->pdev->dev.parent);
		int brightness = bd->props.brightness;
		int ret;

		if ((brightness < 0) \|\| (bd->props.max_brightness < brightness)) {
		dev_err(&bd->dev, "invalid brightness, %d\n", brightness);
		return -EINVAL;
		}

		dev_dbg(&bd->dev, "brightness=%d, power=%d, state=%d\n",
		bd->props.brightness, bd->props.power, bd->props.state);

		if ((bd->props.power != FB_BLANK_UNBLANK) \|\|
		(bd->props.state & BL_CORE_FBBLANK) \|\|
		(bd->props.state & BL_CORE_SUSPENDED))
		brightness = 0;

		ret = aat2870->write(aat2870, AAT2870_BLM,
		(u8)aat2870_brightness(aat2870_bl, brightness));
		if (ret < 0)
		return ret;

		if (brightness == 0) {
		ret = aat2870_bl_disable(aat2870_bl);
		if (ret < 0)
		return ret;
		} else if (aat2870_bl->brightness == 0) {
		ret = aat2870_bl_enable(aat2870_bl);
		if (ret < 0)
		return ret;
		}

		aat2870_bl->brightness = brightness;

		return 0;
		}

		static int aat2870_bl_check_fb(struct backlight_device bd, struct fb_info fi)
		{
		return 1;
		}

		static const struct backlight_ops aat2870_bl_ops = {
		.options = BL_CORE_SUSPENDRESUME,
		.get_brightness = aat2870_bl_get_brightness,
		.update_status = aat2870_bl_update_status,
		.check_fb = aat2870_bl_check_fb,
		};

		static int aat2870_bl_probe(struct platform_device *pdev)
		{
		struct aat2870_bl_platform_data *pdata = pdev->dev.platform_data;
		struct aat2870_bl_driver_data *aat2870_bl;
		struct backlight_device *bd;
		struct backlight_properties props;
		int ret = 0;

		if (!pdata) {
		dev_err(&pdev->dev, "No platform data\n");
		ret = -ENXIO;
		goto out;
		}

		if (pdev->id != AAT2870_ID_BL) {
		dev_err(&pdev->dev, "Invalid device ID, %d\n", pdev->id);
		ret = -EINVAL;
		goto out;
		}

		aat2870_bl = kzalloc(sizeof(struct aat2870_bl_driver_data), GFP_KERNEL);
		if (!aat2870_bl) {
		dev_err(&pdev->dev,
		"Failed to allocate memory for aat2870 backlight\n");
		ret = -ENOMEM;
		goto out;
		}

		memset(&props, 0, sizeof(struct backlight_properties));

		props.type = BACKLIGHT_RAW;
		bd = backlight_device_register("aat2870-backlight", &pdev->dev,
		aat2870_bl, &aat2870_bl_ops, &props);
		if (!bd) {
		dev_err(&pdev->dev,
		"Failed allocate memory for backlight device\n");
		ret = -ENOMEM;
		goto out_kfree;
		}

		aat2870_bl->pdev = pdev;
		platform_set_drvdata(pdev, aat2870_bl);

		aat2870_bl->bd = bd;

		if (pdata->channels > 0)
		aat2870_bl->channels = pdata->channels;
		else
		aat2870_bl->channels = AAT2870_BL_CH_ALL;

		if (pdata->max_brightness > 0)
		aat2870_bl->max_current = pdata->max_current;
		else
		aat2870_bl->max_current = AAT2870_CURRENT_27_9;

		if (pdata->max_brightness > 0)
		bd->props.max_brightness = pdata->max_brightness;
		else
		bd->props.max_brightness = 255;

		aat2870_bl->brightness = 0;
		bd->props.power = FB_BLANK_UNBLANK;
		bd->props.brightness = bd->props.max_brightness;

		ret = aat2870_bl_update_status(bd);
		if (ret < 0) {
		dev_err(&pdev->dev, "Failed to initialize\n");
		goto out_bl_dev_unregister;
		}

		return 0;

		out_bl_dev_unregister:
		backlight_device_unregister(bd);
		out_kfree:
		kfree(aat2870_bl);
		out:
		return ret;
		}

		static int aat2870_bl_remove(struct platform_device *pdev)
		{
		struct aat2870_bl_driver_data *aat2870_bl = platform_get_drvdata(pdev);
		struct backlight_device *bd = aat2870_bl->bd;

		bd->props.power = FB_BLANK_POWERDOWN;
		bd->props.brightness = 0;
		backlight_update_status(bd);

		backlight_device_unregister(bd);
		kfree(aat2870_bl);

		return 0;
		}

		static struct platform_driver aat2870_bl_driver = {
		.driver = {
		.name = "aat2870-backlight",
		.owner = THIS_MODULE,
		},
		.probe = aat2870_bl_probe,
		.remove = aat2870_bl_remove,
		};

		static int __init aat2870_bl_init(void)
		{
		return platform_driver_register(&aat2870_bl_driver);
		}
		subsys_initcall(aat2870_bl_init);

		static void __exit aat2870_bl_exit(void)
		{
		platform_driver_unregister(&aat2870_bl_driver);
		}
		module_exit(aat2870_bl_exit);

		MODULE_DESCRIPTION("AnalogicTech AAT2870 Backlight");
		MODULE_LICENSE("GPL");
		MODULE_AUTHOR("Jin Park <jinyoungp@nvidia.com>");