LXR linux/drivers/video/backlight/ipaq_micro

   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 *
   4 * iPAQ microcontroller backlight support
   5 * Author : Linus Walleij <linus.walleij@linaro.org>
   6 */
   7
   8#include <linux/backlight.h>
   9#include <linux/err.h>
  10#include <linux/fb.h>
  11#include <linux/init.h>
  12#include <linux/mfd/ipaq-micro.h>
  13#include <linux/module.h>
  14#include <linux/platform_device.h>
  15
  16static int micro_bl_update_status(struct backlight_device *bd)
  17{
  18        struct ipaq_micro *micro = dev_get_drvdata(&bd->dev);
  19        int intensity = bd->props.brightness;
  20        struct ipaq_micro_msg msg = {
  21                .id = MSG_BACKLIGHT,
  22                .tx_len = 3,
  23        };
  24
  25        if (bd->props.power != FB_BLANK_UNBLANK)
  26                intensity = 0;
  27        if (bd->props.state & (BL_CORE_FBBLANK | BL_CORE_SUSPENDED))
  28                intensity = 0;
  29
  30        /*
  31         * Message format:
  32         * Byte 0: backlight instance (usually 1)
  33         * Byte 1: on/off
  34         * Byte 2: intensity, 0-255
  35         */
  36        msg.tx_data[0] = 0x01;
  37        msg.tx_data[1] = intensity > 0 ? 1 : 0;
  38        msg.tx_data[2] = intensity;
  39        return ipaq_micro_tx_msg_sync(micro, &msg);
  40}
  41
  42static const struct backlight_ops micro_bl_ops = {
  43        .options = BL_CORE_SUSPENDRESUME,
  44        .update_status  = micro_bl_update_status,
  45};
  46
  47static const struct backlight_properties micro_bl_props = {
  48        .type = BACKLIGHT_RAW,
  49        .max_brightness = 255,
  50        .power = FB_BLANK_UNBLANK,
  51        .brightness = 64,
  52};
  53
  54static int micro_backlight_probe(struct platform_device *pdev)
  55{
  56        struct backlight_device *bd;
  57        struct ipaq_micro *micro = dev_get_drvdata(pdev->dev.parent);
  58
  59        bd = devm_backlight_device_register(&pdev->dev, "ipaq-micro-backlight",
  60                                            &pdev->dev, micro, &micro_bl_ops,
  61                                            &micro_bl_props);
  62        if (IS_ERR(bd))
  63                return PTR_ERR(bd);
  64
  65        platform_set_drvdata(pdev, bd);
  66        backlight_update_status(bd);
  67
  68        return 0;
  69}
  70
  71static struct platform_driver micro_backlight_device_driver = {
  72        .driver = {
  73                .name    = "ipaq-micro-backlight",
  74        },
  75        .probe   = micro_backlight_probe,
  76};
  77module_platform_driver(micro_backlight_device_driver);
  78
  79MODULE_LICENSE("GPL v2");
  80MODULE_DESCRIPTION("driver for iPAQ Atmel micro backlight");
  81MODULE_ALIAS("platform:ipaq-micro-backlight");
  82