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kernel/linux-rt-4.4.41/drivers/video/backlight/ipaq_micro_bl.c 2.12 KB
5113f6f70   김현기   kernel add
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  /*
   * 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.
   *
   * iPAQ microcontroller backlight support
   * Author : Linus Walleij <linus.walleij@linaro.org>
   */
  
  #include <linux/backlight.h>
  #include <linux/err.h>
  #include <linux/fb.h>
  #include <linux/init.h>
  #include <linux/mfd/ipaq-micro.h>
  #include <linux/module.h>
  #include <linux/platform_device.h>
  
  static int micro_bl_update_status(struct backlight_device *bd)
  {
  	struct ipaq_micro *micro = dev_get_drvdata(&bd->dev);
  	int intensity = bd->props.brightness;
  	struct ipaq_micro_msg msg = {
  		.id = MSG_BACKLIGHT,
  		.tx_len = 3,
  	};
  
  	if (bd->props.power != FB_BLANK_UNBLANK)
  		intensity = 0;
  	if (bd->props.state & (BL_CORE_FBBLANK | BL_CORE_SUSPENDED))
  		intensity = 0;
  
  	/*
  	 * Message format:
  	 * Byte 0: backlight instance (usually 1)
  	 * Byte 1: on/off
  	 * Byte 2: intensity, 0-255
  	 */
  	msg.tx_data[0] = 0x01;
  	msg.tx_data[1] = intensity > 0 ? 1 : 0;
  	msg.tx_data[2] = intensity;
  	return ipaq_micro_tx_msg_sync(micro, &msg);
  }
  
  static const struct backlight_ops micro_bl_ops = {
  	.options = BL_CORE_SUSPENDRESUME,
  	.update_status  = micro_bl_update_status,
  };
  
  static struct backlight_properties micro_bl_props = {
  	.type = BACKLIGHT_RAW,
  	.max_brightness = 255,
  	.power = FB_BLANK_UNBLANK,
  	.brightness = 64,
  };
  
  static int micro_backlight_probe(struct platform_device *pdev)
  {
  	struct backlight_device *bd;
  	struct ipaq_micro *micro = dev_get_drvdata(pdev->dev.parent);
  
  	bd = devm_backlight_device_register(&pdev->dev, "ipaq-micro-backlight",
  					    &pdev->dev, micro, &micro_bl_ops,
  					    &micro_bl_props);
  	if (IS_ERR(bd))
  		return PTR_ERR(bd);
  
  	platform_set_drvdata(pdev, bd);
  	backlight_update_status(bd);
  
  	return 0;
  }
  
  static struct platform_driver micro_backlight_device_driver = {
  	.driver = {
  		.name    = "ipaq-micro-backlight",
  	},
  	.probe   = micro_backlight_probe,
  };
  module_platform_driver(micro_backlight_device_driver);
  
  MODULE_LICENSE("GPL v2");
  MODULE_DESCRIPTION("driver for iPAQ Atmel micro backlight");
  MODULE_ALIAS("platform:ipaq-micro-backlight");