/* * linux/drivers/video/backlight/adx.c * * Copyright (C) 2009 Avionic Design GmbH * * 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. * * Written by Thierry Reding <thierry.reding@avionic-design.de> */ #include <linux/backlight.h> #include <linux/fb.h> #include <linux/gfp.h> #include <linux/io.h> #include <linux/module.h> #include <linux/platform_device.h> /* register definitions */ #define ADX_BACKLIGHT_CONTROL 0x00 #define ADX_BACKLIGHT_CONTROL_ENABLE (1 << 0) #define ADX_BACKLIGHT_BRIGHTNESS 0x08 #define ADX_BACKLIGHT_STATUS 0x10 #define ADX_BACKLIGHT_ERROR 0x18 struct adxbl { void __iomem *base; }; static int adx_backlight_update_status(struct backlight_device *bldev) { struct adxbl *bl = bl_get_data(bldev); u32 value; value = bldev->props.brightness; writel(value, bl->base + ADX_BACKLIGHT_BRIGHTNESS); value = readl(bl->base + ADX_BACKLIGHT_CONTROL); if (bldev->props.state & BL_CORE_FBBLANK) value &= ~ADX_BACKLIGHT_CONTROL_ENABLE; else value |= ADX_BACKLIGHT_CONTROL_ENABLE; writel(value, bl->base + ADX_BACKLIGHT_CONTROL); return 0; } static int adx_backlight_get_brightness(struct backlight_device *bldev) { struct adxbl *bl = bl_get_data(bldev); u32 brightness; brightness = readl(bl->base + ADX_BACKLIGHT_BRIGHTNESS); return brightness & 0xff; } static int adx_backlight_check_fb(struct backlight_device *bldev, struct fb_info *fb) { return 1; } static const struct backlight_ops adx_backlight_ops = { .options = 0, .update_status = adx_backlight_update_status, .get_brightness = adx_backlight_get_brightness, .check_fb = adx_backlight_check_fb, }; static int __devinit adx_backlight_probe(struct platform_device *pdev) { struct backlight_properties props; struct backlight_device *bldev; struct resource *res; struct adxbl *bl; int ret = 0; res = platform_get_resource(pdev, IORESOURCE_MEM, 0); if (!res) { ret = -ENXIO; goto out; } res = devm_request_mem_region(&pdev->dev, res->start, resource_size(res), res->name); if (!res) { ret = -ENXIO; goto out; } bl = devm_kzalloc(&pdev->dev, sizeof(*bl), GFP_KERNEL); if (!bl) { ret = -ENOMEM; goto out; } bl->base = devm_ioremap_nocache(&pdev->dev, res->start, resource_size(res)); if (!bl->base) { ret = -ENXIO; goto out; } memset(&props, 0, sizeof(struct backlight_properties)); props.max_brightness = 0xff; bldev = backlight_device_register(dev_name(&pdev->dev), &pdev->dev, bl, &adx_backlight_ops, &props); if (!bldev) { ret = -ENOMEM; goto out; } bldev->props.brightness = 0xff; bldev->props.power = FB_BLANK_UNBLANK; platform_set_drvdata(pdev, bldev); out: return ret; } static int __devexit adx_backlight_remove(struct platform_device *pdev) { struct backlight_device *bldev; int ret = 0; bldev = platform_get_drvdata(pdev); bldev->props.power = FB_BLANK_UNBLANK; bldev->props.brightness = 0xff; backlight_update_status(bldev); backlight_device_unregister(bldev); platform_set_drvdata(pdev, NULL); return ret; } #ifdef CONFIG_PM static int adx_backlight_suspend(struct platform_device *pdev, pm_message_t state) { return 0; } static int adx_backlight_resume(struct platform_device *pdev) { return 0; } #else #define adx_backlight_suspend NULL #define adx_backlight_resume NULL #endif static struct platform_driver adx_backlight_driver = { .probe = adx_backlight_probe, .remove = __devexit_p(adx_backlight_remove), .suspend = adx_backlight_suspend, .resume = adx_backlight_resume, .driver = { .name = "adx-backlight", .owner = THIS_MODULE, }, }; static int __init adx_backlight_init(void) { return platform_driver_register(&adx_backlight_driver); } static void __exit adx_backlight_exit(void) { platform_driver_unregister(&adx_backlight_driver); } module_init(adx_backlight_init); module_exit(adx_backlight_exit); MODULE_AUTHOR("Thierry Reding <thierry.reding@avionic-design.de>"); MODULE_DESCRIPTION("Avionic Design Xanthos Backlight Driver"); MODULE_LICENSE("GPL v2");