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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * linux/drivers/video/backlight/aat2870_bl.c4 *5 * Copyright (c) 2011, NVIDIA Corporation.6 * Author: Jin Park <jinyoungp@nvidia.com>7 */8 9#include <linux/module.h>10#include <linux/kernel.h>11#include <linux/init.h>12#include <linux/platform_device.h>13#include <linux/mutex.h>14#include <linux/delay.h>15#include <linux/backlight.h>16#include <linux/mfd/aat2870.h>17 18struct aat2870_bl_driver_data {19 struct platform_device *pdev;20 struct backlight_device *bd;21 22 int channels;23 int max_current;24 int brightness; /* current brightness */25};26 27static inline int aat2870_brightness(struct aat2870_bl_driver_data *aat2870_bl,28 int brightness)29{30 struct backlight_device *bd = aat2870_bl->bd;31 int val;32 33 val = brightness * (aat2870_bl->max_current - 1);34 val /= bd->props.max_brightness;35 36 return val;37}38 39static inline int aat2870_bl_enable(struct aat2870_bl_driver_data *aat2870_bl)40{41 struct aat2870_data *aat287042 = dev_get_drvdata(aat2870_bl->pdev->dev.parent);43 44 return aat2870->write(aat2870, AAT2870_BL_CH_EN,45 (u8)aat2870_bl->channels);46}47 48static inline int aat2870_bl_disable(struct aat2870_bl_driver_data *aat2870_bl)49{50 struct aat2870_data *aat287051 = dev_get_drvdata(aat2870_bl->pdev->dev.parent);52 53 return aat2870->write(aat2870, AAT2870_BL_CH_EN, 0x0);54}55 56static int aat2870_bl_update_status(struct backlight_device *bd)57{58 struct aat2870_bl_driver_data *aat2870_bl = bl_get_data(bd);59 struct aat2870_data *aat2870 =60 dev_get_drvdata(aat2870_bl->pdev->dev.parent);61 int brightness = backlight_get_brightness(bd);62 int ret;63 64 if ((brightness < 0) || (bd->props.max_brightness < brightness)) {65 dev_err(&bd->dev, "invalid brightness, %d\n", brightness);66 return -EINVAL;67 }68 69 dev_dbg(&bd->dev, "brightness=%d, power=%d, state=%d\n",70 bd->props.brightness, bd->props.power, bd->props.state);71 72 ret = aat2870->write(aat2870, AAT2870_BLM,73 (u8)aat2870_brightness(aat2870_bl, brightness));74 if (ret < 0)75 return ret;76 77 if (brightness == 0) {78 ret = aat2870_bl_disable(aat2870_bl);79 if (ret < 0)80 return ret;81 } else if (aat2870_bl->brightness == 0) {82 ret = aat2870_bl_enable(aat2870_bl);83 if (ret < 0)84 return ret;85 }86 87 aat2870_bl->brightness = brightness;88 89 return 0;90}91 92static const struct backlight_ops aat2870_bl_ops = {93 .options = BL_CORE_SUSPENDRESUME,94 .update_status = aat2870_bl_update_status,95};96 97static int aat2870_bl_probe(struct platform_device *pdev)98{99 struct aat2870_bl_platform_data *pdata = dev_get_platdata(&pdev->dev);100 struct aat2870_bl_driver_data *aat2870_bl;101 struct backlight_device *bd;102 struct backlight_properties props;103 int ret = 0;104 105 if (!pdata) {106 dev_err(&pdev->dev, "No platform data\n");107 ret = -ENXIO;108 goto out;109 }110 111 if (pdev->id != AAT2870_ID_BL) {112 dev_err(&pdev->dev, "Invalid device ID, %d\n", pdev->id);113 ret = -EINVAL;114 goto out;115 }116 117 aat2870_bl = devm_kzalloc(&pdev->dev,118 sizeof(struct aat2870_bl_driver_data),119 GFP_KERNEL);120 if (!aat2870_bl) {121 ret = -ENOMEM;122 goto out;123 }124 125 memset(&props, 0, sizeof(struct backlight_properties));126 127 props.type = BACKLIGHT_RAW;128 bd = devm_backlight_device_register(&pdev->dev, "aat2870-backlight",129 &pdev->dev, aat2870_bl, &aat2870_bl_ops,130 &props);131 if (IS_ERR(bd)) {132 dev_err(&pdev->dev,133 "Failed allocate memory for backlight device\n");134 ret = PTR_ERR(bd);135 goto out;136 }137 138 aat2870_bl->pdev = pdev;139 platform_set_drvdata(pdev, aat2870_bl);140 141 aat2870_bl->bd = bd;142 143 if (pdata->channels > 0)144 aat2870_bl->channels = pdata->channels;145 else146 aat2870_bl->channels = AAT2870_BL_CH_ALL;147 148 if (pdata->max_current > 0)149 aat2870_bl->max_current = pdata->max_current;150 else151 aat2870_bl->max_current = AAT2870_CURRENT_27_9;152 153 if (pdata->max_brightness > 0)154 bd->props.max_brightness = pdata->max_brightness;155 else156 bd->props.max_brightness = 255;157 158 aat2870_bl->brightness = 0;159 bd->props.power = BACKLIGHT_POWER_ON;160 bd->props.brightness = bd->props.max_brightness;161 162 ret = aat2870_bl_update_status(bd);163 if (ret < 0) {164 dev_err(&pdev->dev, "Failed to initialize\n");165 return ret;166 }167 168 return 0;169 170out:171 return ret;172}173 174static void aat2870_bl_remove(struct platform_device *pdev)175{176 struct aat2870_bl_driver_data *aat2870_bl = platform_get_drvdata(pdev);177 struct backlight_device *bd = aat2870_bl->bd;178 179 bd->props.power = BACKLIGHT_POWER_OFF;180 bd->props.brightness = 0;181 backlight_update_status(bd);182}183 184static struct platform_driver aat2870_bl_driver = {185 .driver = {186 .name = "aat2870-backlight",187 },188 .probe = aat2870_bl_probe,189 .remove_new = aat2870_bl_remove,190};191 192static int __init aat2870_bl_init(void)193{194 return platform_driver_register(&aat2870_bl_driver);195}196subsys_initcall(aat2870_bl_init);197 198static void __exit aat2870_bl_exit(void)199{200 platform_driver_unregister(&aat2870_bl_driver);201}202module_exit(aat2870_bl_exit);203 204MODULE_DESCRIPTION("AnalogicTech AAT2870 Backlight");205MODULE_LICENSE("GPL");206MODULE_AUTHOR("Jin Park <jinyoungp@nvidia.com>");207