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backlight: lcd: Add LCD_POWER_ constants for power states 

Duplicate FB_BLANK_ constants as LCD_POWER_ constants in the lcd
header file. Allows lcd drivers to avoid including the fbdev header
file and removes a compile-time dependency between the two subsystems.

The new LCD_POWER_ constants have the same values as their
FB_BLANK_ counterparts. Hence semantics does not change and the lcd
drivers can be converted one by one. Each instance of FB_BLANK_UNBLANK
becomes LCD_POWER_ON, each of FB_BLANK_POWERDOWN becomes LCD_POWER_OFF,
FB_BLANK_NORMAL becomes LCD_POWER_REDUCED and FB_BLANK_VSYNC_SUSPEND
becomes LCD_POWER_REDUCED_VSYNC_SUSPEND.

Lcd code or drivers do not use FB_BLANK_HSYNC_SUSPEND, so no
new constants for this is being added. The tokens LCD_POWER_REDUCED
and LCD_POWER_REDUCED_VSYNC_SUSPEND are deprecated and drivers should
replace them with LCD_POWER_ON and LCD_POWER_OFF.

See also commit a1cacb8a8e ("backlight: Add BACKLIGHT_POWER_ constants
for power states"), which added similar constants for backlight drivers.

v2:
- fix typo in commit description

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Link: https://lore.kernel.org/r/20240906075439.98476-4-tzimmermann@suse.de
Signed-off-by: Lee Jones <lee@kernel.org>
pull/1085/head
Thomas Zimmermann 2024-09-06 09:52:17 +02:00 committed by Lee Jones
parent 26228256b7
commit 48ffe2074c
2 changed files with 26 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

22
drivers/video/backlight/lcd.c
View File

@ -20,6 +20,24 @@
#if defined(CONFIG_FB) || (defined(CONFIG_FB_MODULE) && \
defined(CONFIG_LCD_CLASS_DEVICE_MODULE))
static int to_lcd_power(int fb_blank)
{
switch (fb_blank) {
case FB_BLANK_UNBLANK:
return LCD_POWER_ON;
/* deprecated; TODO: should become 'off' */
case FB_BLANK_NORMAL:
return LCD_POWER_REDUCED;
case FB_BLANK_VSYNC_SUSPEND:
return LCD_POWER_REDUCED_VSYNC_SUSPEND;
/* 'off' */
case FB_BLANK_HSYNC_SUSPEND:
case FB_BLANK_POWERDOWN:
default:
return LCD_POWER_OFF;
}
}
/* This callback gets called when something important happens inside a
* framebuffer driver. We're looking if that important event is blanking,
* and if it is, we're switching lcd power as well ...
@ -42,8 +60,10 @@ static int fb_notifier_callback(struct notifier_block *self,
return 0;
if (event == FB_EVENT_BLANK) {
int power = to_lcd_power(*(int *)evdata->data);
if (ld->ops->set_power)
ld->ops->set_power(ld, *(int *)evdata->data);
ld->ops->set_power(ld, power);
} else {
if (ld->ops->set_mode)
ld->ops->set_mode(ld, evdata->data);

5
include/linux/lcd.h
View File

@ -14,6 +14,11 @@
#include <linux/notifier.h>
#include <linux/fb.h>
#define LCD_POWER_ON (0)
#define LCD_POWER_REDUCED (1) // deprecated; don't use in new code
#define LCD_POWER_REDUCED_VSYNC_SUSPEND (2) // deprecated; don't use in new code
#define LCD_POWER_OFF (4)
/* Notes on locking:
*
* lcd_device->ops_lock is an internal backlight lock protecting the ops