mirror of
https://github.com/Qortal/Brooklyn.git
synced 2025-01-31 15:22:18 +00:00
120 lines
2.9 KiB
C
120 lines
2.9 KiB
C
/*
|
|
* rpi_bl.c - Backlight controller through VPU
|
|
*
|
|
* 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.
|
|
*/
|
|
|
|
#include <linux/backlight.h>
|
|
#include <linux/err.h>
|
|
#include <linux/fb.h>
|
|
#include <linux/gpio.h>
|
|
#include <linux/init.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/module.h>
|
|
#include <linux/of.h>
|
|
#include <linux/of_gpio.h>
|
|
#include <linux/platform_device.h>
|
|
#include <linux/slab.h>
|
|
#include <soc/bcm2835/raspberrypi-firmware.h>
|
|
|
|
struct rpi_backlight {
|
|
struct device *dev;
|
|
struct device *fbdev;
|
|
struct rpi_firmware *fw;
|
|
};
|
|
|
|
static int rpi_backlight_update_status(struct backlight_device *bl)
|
|
{
|
|
struct rpi_backlight *gbl = bl_get_data(bl);
|
|
int brightness = bl->props.brightness;
|
|
int ret;
|
|
|
|
if (bl->props.power != FB_BLANK_UNBLANK ||
|
|
bl->props.fb_blank != FB_BLANK_UNBLANK ||
|
|
bl->props.state & (BL_CORE_SUSPENDED | BL_CORE_FBBLANK))
|
|
brightness = 0;
|
|
|
|
ret = rpi_firmware_property(gbl->fw,
|
|
RPI_FIRMWARE_FRAMEBUFFER_SET_BACKLIGHT,
|
|
&brightness, sizeof(brightness));
|
|
if (ret) {
|
|
dev_err(gbl->dev, "Failed to set brightness\n");
|
|
return ret;
|
|
}
|
|
|
|
if (brightness < 0) {
|
|
dev_err(gbl->dev, "Backlight change failed\n");
|
|
return -EAGAIN;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct backlight_ops rpi_backlight_ops = {
|
|
.options = BL_CORE_SUSPENDRESUME,
|
|
.update_status = rpi_backlight_update_status,
|
|
};
|
|
|
|
static int rpi_backlight_probe(struct platform_device *pdev)
|
|
{
|
|
struct backlight_properties props;
|
|
struct backlight_device *bl;
|
|
struct rpi_backlight *gbl;
|
|
struct device_node *fw_node;
|
|
|
|
gbl = devm_kzalloc(&pdev->dev, sizeof(*gbl), GFP_KERNEL);
|
|
if (gbl == NULL)
|
|
return -ENOMEM;
|
|
|
|
gbl->dev = &pdev->dev;
|
|
|
|
fw_node = of_parse_phandle(pdev->dev.of_node, "firmware", 0);
|
|
if (!fw_node) {
|
|
dev_err(&pdev->dev, "Missing firmware node\n");
|
|
return -ENOENT;
|
|
}
|
|
|
|
gbl->fw = rpi_firmware_get(fw_node);
|
|
if (!gbl->fw)
|
|
return -EPROBE_DEFER;
|
|
|
|
memset(&props, 0, sizeof(props));
|
|
props.type = BACKLIGHT_RAW;
|
|
props.max_brightness = 255;
|
|
bl = devm_backlight_device_register(&pdev->dev, dev_name(&pdev->dev),
|
|
&pdev->dev, gbl, &rpi_backlight_ops,
|
|
&props);
|
|
if (IS_ERR(bl)) {
|
|
dev_err(&pdev->dev, "failed to register backlight\n");
|
|
return PTR_ERR(bl);
|
|
}
|
|
|
|
bl->props.brightness = 255;
|
|
backlight_update_status(bl);
|
|
|
|
platform_set_drvdata(pdev, bl);
|
|
return 0;
|
|
}
|
|
|
|
static const struct of_device_id rpi_backlight_of_match[] = {
|
|
{ .compatible = "raspberrypi,rpi-backlight" },
|
|
{ /* sentinel */ }
|
|
};
|
|
MODULE_DEVICE_TABLE(of, rpi_backlight_of_match);
|
|
|
|
static struct platform_driver rpi_backlight_driver = {
|
|
.driver = {
|
|
.name = "rpi-backlight",
|
|
.of_match_table = of_match_ptr(rpi_backlight_of_match),
|
|
},
|
|
.probe = rpi_backlight_probe,
|
|
};
|
|
|
|
module_platform_driver(rpi_backlight_driver);
|
|
|
|
MODULE_AUTHOR("Gordon Hollingworth <gordon@raspberrypi.org>");
|
|
MODULE_DESCRIPTION("Raspberry Pi mailbox based Backlight Driver");
|
|
MODULE_LICENSE("GPL");
|