LXR linux/drivers/video/backlight/ipaq_micro

   1/*
   2 * This program is free software; you can redistribute it and/or modify
   3 * it under the terms of the GNU General Public License version 2 as
   4 * published by the Free Software Foundation.
   5 *
   6 * iPAQ microcontroller backlight support
   7 * Author : Linus Walleij <linus.walleij@linaro.org>
   8 */
   9
  10#include <linux/backlight.h>
  11#include <linux/err.h>
  12#include <linux/fb.h>
  13#include <linux/init.h>
  14#include <linux/mfd/ipaq-micro.h>
  15#include <linux/module.h>
  16#include <linux/platform_device.h>
  17
  18static int micro_bl_update_status(struct backlight_device *bd)
  19{
  20        struct ipaq_micro *micro = dev_get_drvdata(&bd->dev);
  21        int intensity = bd->props.brightness;
  22        struct ipaq_micro_msg msg = {
  23                .id = MSG_BACKLIGHT,
  24                .tx_len = 3,
  25        };
  26
  27        if (bd->props.power != FB_BLANK_UNBLANK)
  28                intensity = 0;
  29        if (bd->props.state & (BL_CORE_FBBLANK | BL_CORE_SUSPENDED))
  30                intensity = 0;
  31
  32        /*
  33         * Message format:
  34         * Byte 0: backlight instance (usually 1)
  35         * Byte 1: on/off
  36         * Byte 2: intensity, 0-255
  37         */
  38        msg.tx_data[0] = 0x01;
  39        msg.tx_data[1] = intensity > 0 ? 1 : 0;
  40        msg.tx_data[2] = intensity;
  41        return ipaq_micro_tx_msg_sync(micro, &msg);
  42}
  43
  44static const struct backlight_ops micro_bl_ops = {
  45        .options = BL_CORE_SUSPENDRESUME,
  46        .update_status  = micro_bl_update_status,
  47};
  48
  49static struct backlight_properties micro_bl_props = {
  50        .type = BACKLIGHT_RAW,
  51        .max_brightness = 255,
  52        .power = FB_BLANK_UNBLANK,
  53        .brightness = 64,
  54};
  55
  56static int micro_backlight_probe(struct platform_device *pdev)
  57{
  58        struct backlight_device *bd;
  59        struct ipaq_micro *micro = dev_get_drvdata(pdev->dev.parent);
  60
  61        bd = devm_backlight_device_register(&pdev->dev, "ipaq-micro-backlight",
  62                                            &pdev->dev, micro, &micro_bl_ops,
  63                                            &micro_bl_props);
  64        if (IS_ERR(bd))
  65                return PTR_ERR(bd);
  66
  67        platform_set_drvdata(pdev, bd);
  68        backlight_update_status(bd);
  69
  70        return 0;
  71}
  72
  73static struct platform_driver micro_backlight_device_driver = {
  74        .driver = {
  75                .name    = "ipaq-micro-backlight",
  76        },
  77        .probe   = micro_backlight_probe,
  78};
  79module_platform_driver(micro_backlight_device_driver);
  80
  81MODULE_LICENSE("GPL v2");
  82MODULE_DESCRIPTION("driver for iPAQ Atmel micro backlight");
  83MODULE_ALIAS("platform:ipaq-micro-backlight");
  84