linux/drivers/video/backlight/ipaq_micro_bl.c

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// SPDX-License-Identifier: GPL-2.0-only
/*
*
* 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");