diff options
Diffstat (limited to 'drivers/video/backlight/aat2870_bl.c')
| -rw-r--r-- | drivers/video/backlight/aat2870_bl.c | 233 |
1 files changed, 233 insertions, 0 deletions
diff --git a/drivers/video/backlight/aat2870_bl.c b/drivers/video/backlight/aat2870_bl.c new file mode 100644 index 000000000..50774e657 --- /dev/null +++ b/drivers/video/backlight/aat2870_bl.c @@ -0,0 +1,233 @@ +/* + * 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 - 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 = 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, + .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 = 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 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); + + return 0; +} + +static struct platform_driver aat2870_bl_driver = { + .driver = { + .name = "aat2870-backlight", + }, + .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>"); |