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platform/x86: apple-gmux: Add acpi_video_get_backlight_type() check

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Make apple-gmux backlight registration honor the acpi_backlight=...
kernel commandline option which is used to select the backlight
control method on x86/ACPI devices.

Reported-and-tested-by: Aditya Garg <gargaditya08@live.com>
Link: https://lore.kernel.org/platform-driver-x86/BM1PR01MB0931B467250831916F7C55B3B8A59@BM1PR01MB0931.INDPRD01.PROD.OUTLOOK.COM/
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20230307113813.359743-1-hdegoede@redhat.com
This commit is contained in:
Hans de Goede 2023-03-07 12:38:13 +01:00
parent f863fac1b1
commit d2e6832147
1 changed files with 33 additions and 26 deletions
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59
drivers/platform/x86/apple-gmux.c
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@ -23,6 +23,7 @@
#include <linux/pci.h>
#include <linux/vga_switcheroo.h>
#include <linux/debugfs.h>
#include <acpi/video.h>
#include <asm/io.h>
/**
@ -781,8 +782,9 @@ static int gmux_probe(struct pnp_dev *pnp, const struct pnp_device_id *id)
struct apple_gmux_data *gmux_data;
struct resource *res;
struct backlight_properties props;
struct backlight_device *bdev;
struct backlight_device *bdev = NULL;
u8 ver_major, ver_minor, ver_release;
bool register_bdev = true;
int ret = -ENXIO;
acpi_status status;
unsigned long long gpe;
@ -859,34 +861,39 @@ get_version:
props.type = BACKLIGHT_PLATFORM;
props.max_brightness = gmux_read32(gmux_data, GMUX_PORT_MAX_BRIGHTNESS);
/*
* Currently it's assumed that the maximum brightness is less than
* 2^24 for compatibility with old gmux versions. Cap the max
* brightness at this value, but print a warning if the hardware
* reports something higher so that it can be fixed.
*/
if (WARN_ON(props.max_brightness > GMUX_MAX_BRIGHTNESS))
props.max_brightness = GMUX_MAX_BRIGHTNESS;
#if IS_REACHABLE(CONFIG_ACPI_VIDEO)
register_bdev = acpi_video_get_backlight_type() == acpi_backlight_apple_gmux;
#endif
if (register_bdev) {
/*
* Currently it's assumed that the maximum brightness is less than
* 2^24 for compatibility with old gmux versions. Cap the max
* brightness at this value, but print a warning if the hardware
* reports something higher so that it can be fixed.
*/
if (WARN_ON(props.max_brightness > GMUX_MAX_BRIGHTNESS))
props.max_brightness = GMUX_MAX_BRIGHTNESS;
bdev = backlight_device_register("gmux_backlight", &pnp->dev,
gmux_data, &gmux_bl_ops, &props);
if (IS_ERR(bdev)) {
ret = PTR_ERR(bdev);
goto err_unmap;
bdev = backlight_device_register("gmux_backlight", &pnp->dev,
gmux_data, &gmux_bl_ops, &props);
if (IS_ERR(bdev)) {
ret = PTR_ERR(bdev);
goto err_unmap;
}
gmux_data->bdev = bdev;
bdev->props.brightness = gmux_get_brightness(bdev);
backlight_update_status(bdev);
/*
* The backlight situation on Macs is complicated. If the gmux is
* present it's the best choice, because it always works for
* backlight control and supports more levels than other options.
* Disable the other backlight choices.
*/
apple_bl_unregister();
}
gmux_data->bdev = bdev;
bdev->props.brightness = gmux_get_brightness(bdev);
backlight_update_status(bdev);
/*
* The backlight situation on Macs is complicated. If the gmux is
* present it's the best choice, because it always works for
* backlight control and supports more levels than other options.
* Disable the other backlight choices.
*/
apple_bl_unregister();
gmux_data->power_state = VGA_SWITCHEROO_ON;
gmux_data->dhandle = ACPI_HANDLE(&pnp->dev);