| // SPDX-License-Identifier: GPL-2.0-only |
| /* |
| * linux/drivers/video/backlight/aat2870_bl.c |
| * |
| * Copyright (c) 2011, NVIDIA Corporation. |
| * Author: Jin Park <jinyoungp@nvidia.com> |
| */ |
| |
| #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/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 - 1); |
| 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_update_status(struct backlight_device *bd) |
| { |
| struct aat2870_bl_driver_data *aat2870_bl = bl_get_data(bd); |
| struct aat2870_data *aat2870 = |
| dev_get_drvdata(aat2870_bl->pdev->dev.parent); |
| int brightness = backlight_get_brightness(bd); |
| 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); |
| |
| 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 const struct backlight_ops aat2870_bl_ops = { |
| .options = BL_CORE_SUSPENDRESUME, |
| .update_status = aat2870_bl_update_status, |
| }; |
| |
| static int aat2870_bl_probe(struct platform_device *pdev) |
| { |
| struct aat2870_bl_platform_data *pdata = dev_get_platdata(&pdev->dev); |
| 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 = devm_kzalloc(&pdev->dev, |
| sizeof(struct aat2870_bl_driver_data), |
| GFP_KERNEL); |
| if (!aat2870_bl) { |
| ret = -ENOMEM; |
| goto out; |
| } |
| |
| memset(&props, 0, sizeof(struct backlight_properties)); |
| |
| props.type = BACKLIGHT_RAW; |
| bd = devm_backlight_device_register(&pdev->dev, "aat2870-backlight", |
| &pdev->dev, aat2870_bl, &aat2870_bl_ops, |
| &props); |
| if (IS_ERR(bd)) { |
| dev_err(&pdev->dev, |
| "Failed allocate memory for backlight device\n"); |
| ret = PTR_ERR(bd); |
| goto out; |
| } |
| |
| 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_current > 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"); |
| return ret; |
| } |
| |
| return 0; |
| |
| out: |
| return ret; |
| } |
| |
| static void 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); |
| } |
| |
| static struct platform_driver aat2870_bl_driver = { |
| .driver = { |
| .name = "aat2870-backlight", |
| }, |
| .probe = aat2870_bl_probe, |
| .remove_new = 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>"); |