diff options
Diffstat (limited to 'drivers/video/backlight/mxc_lcdc_bl.c')
| -rw-r--r-- | drivers/video/backlight/mxc_lcdc_bl.c | 164 |
1 files changed, 164 insertions, 0 deletions
diff --git a/drivers/video/backlight/mxc_lcdc_bl.c b/drivers/video/backlight/mxc_lcdc_bl.c new file mode 100644 index 000000000000..e49d72632290 --- /dev/null +++ b/drivers/video/backlight/mxc_lcdc_bl.c @@ -0,0 +1,164 @@ +/* + * Copyright 2007-2010 Freescale Semiconductor, Inc. All Rights Reserved. + */ + +/* + * The code contained herein is licensed under the GNU General Public + * License. You may obtain a copy of the GNU General Public License + * Version 2 or later at the following locations: + * + * http://www.opensource.org/licenses/gpl-license.html + * http://www.gnu.org/copyleft/gpl.html + */ +/*! + * @defgroup LCDC_BL MXC LCDC Backlight Driver + */ +/*! + * @file mxc_lcdc_bl.c + * + * @brief Backlight Driver for LCDC PWM on Freescale MXC/i.MX platforms. + * + * This file contains API defined in include/linux/clk.h for setting up and + * retrieving clocks. + * + * Based on Sharp's Corgi Backlight Driver + * + * @ingroup LCDC_BL + */ + +#include <linux/slab.h> +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/platform_device.h> +#include <linux/spinlock.h> +#include <linux/fb.h> +#include <linux/backlight.h> +#include <linux/clk.h> + +#define MXC_MAX_INTENSITY 255 +#define MXC_DEFAULT_INTENSITY 127 +#define MXC_INTENSITY_OFF 0 + +extern void mx2fb_set_brightness(uint8_t); + +struct mxcbl_dev_data { + struct clk *clk; + int intensity; +}; + +static int mxcbl_send_intensity(struct backlight_device *bd) +{ + int intensity = bd->props.brightness; + struct mxcbl_dev_data *devdata = dev_get_drvdata(&bd->dev); + + if (bd->props.power != FB_BLANK_UNBLANK) + intensity = 0; + if (bd->props.fb_blank != FB_BLANK_UNBLANK) + intensity = 0; + + if ((devdata->intensity == 0) && (intensity != 0)) + clk_enable(devdata->clk); + + /* PWM contrast control register */ + mx2fb_set_brightness(intensity); + + if ((devdata->intensity != 0) && (intensity == 0)) + clk_disable(devdata->clk); + + devdata->intensity = intensity; + return 0; +} + +static int mxcbl_get_intensity(struct backlight_device *bd) +{ + struct mxcbl_dev_data *devdata = dev_get_drvdata(&bd->dev); + return devdata->intensity; +} + +static int mxcbl_check_fb(struct backlight_device *bd, struct fb_info *info) +{ + if (strcmp(info->fix.id, "DISP0 BG") == 0) { + return 1; + } + return 0; +} + +static struct backlight_ops mxcbl_ops = { + .get_brightness = mxcbl_get_intensity, + .update_status = mxcbl_send_intensity, + .check_fb = mxcbl_check_fb, +}; + +static int __init mxcbl_probe(struct platform_device *pdev) +{ + struct backlight_device *bd; + struct mxcbl_dev_data *devdata; + struct backlight_properties props; + int ret = 0; + + devdata = kzalloc(sizeof(struct mxcbl_dev_data), GFP_KERNEL); + if (!devdata) + return -ENOMEM; + + devdata->clk = clk_get(NULL, "lcdc_clk"); + + memset(&props, 0, sizeof(struct backlight_properties)); + props.max_brightness = MXC_MAX_INTENSITY; + + bd = backlight_device_register(dev_name(&pdev->dev), &pdev->dev, devdata, + &mxcbl_ops, &props); + if (IS_ERR(bd)) { + ret = PTR_ERR(bd); + goto err0; + } + platform_set_drvdata(pdev, bd); + + bd->props.brightness = MXC_DEFAULT_INTENSITY; + bd->props.power = FB_BLANK_UNBLANK; + bd->props.fb_blank = FB_BLANK_UNBLANK; + mx2fb_set_brightness(MXC_DEFAULT_INTENSITY); + + printk("MXC Backlight Device %s Initialized.\n", dev_name(&pdev->dev)); + return 0; + err0: + kfree(devdata); + return ret; +} + +static int mxcbl_remove(struct platform_device *pdev) +{ + struct backlight_device *bd = platform_get_drvdata(pdev); + + bd->props.brightness = MXC_INTENSITY_OFF; + backlight_update_status(bd); + + backlight_device_unregister(bd); + + return 0; +} + +static struct platform_driver mxcbl_driver = { + .probe = mxcbl_probe, + .remove = mxcbl_remove, + .driver = { + .name = "mxc_lcdc_bl", + }, +}; + +static int __init mxcbl_init(void) +{ + return platform_driver_register(&mxcbl_driver); +} + +static void __exit mxcbl_exit(void) +{ + platform_driver_unregister(&mxcbl_driver); +} + +module_init(mxcbl_init); +module_exit(mxcbl_exit); + +MODULE_DESCRIPTION("Freescale MXC/i.MX LCDC PWM Backlight Driver"); +MODULE_AUTHOR("Freescale Semiconductor, Inc."); +MODULE_LICENSE("GPL"); |