cab267c65f
Fix a erroneous calculation of the legacy brightness values as reported by Paul Collins. Additionally, it moves the calculation of the negative value in the radeonfb driver after the value check. Signed-off-by: Michael Hanselmann <linux-kernel@hansmi.ch> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Acked-by: Paul Collins <paul@briny.ondioline.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
161 lines
3.4 KiB
C
161 lines
3.4 KiB
C
/*
|
|
* Miscellaneous procedures for dealing with the PowerMac hardware.
|
|
* Contains support for the backlight.
|
|
*
|
|
* Copyright (C) 2000 Benjamin Herrenschmidt
|
|
* Copyright (C) 2006 Michael Hanselmann <linux-kernel@hansmi.ch>
|
|
*
|
|
*/
|
|
|
|
#include <linux/config.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/fb.h>
|
|
#include <linux/backlight.h>
|
|
#include <asm/prom.h>
|
|
#include <asm/backlight.h>
|
|
|
|
#define OLD_BACKLIGHT_MAX 15
|
|
|
|
/* Protect the pmac_backlight variable */
|
|
DEFINE_MUTEX(pmac_backlight_mutex);
|
|
|
|
/* Main backlight storage
|
|
*
|
|
* Backlight drivers in this variable are required to have the "props"
|
|
* attribute set and to have an update_status function.
|
|
*
|
|
* We can only store one backlight here, but since Apple laptops have only one
|
|
* internal display, it doesn't matter. Other backlight drivers can be used
|
|
* independently.
|
|
*
|
|
* Lock ordering:
|
|
* pmac_backlight_mutex (global, main backlight)
|
|
* pmac_backlight->sem (backlight class)
|
|
*/
|
|
struct backlight_device *pmac_backlight;
|
|
|
|
int pmac_has_backlight_type(const char *type)
|
|
{
|
|
struct device_node* bk_node = find_devices("backlight");
|
|
|
|
if (bk_node) {
|
|
char *prop = get_property(bk_node, "backlight-control", NULL);
|
|
if (prop && strncmp(prop, type, strlen(type)) == 0)
|
|
return 1;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
int pmac_backlight_curve_lookup(struct fb_info *info, int value)
|
|
{
|
|
int level = (FB_BACKLIGHT_LEVELS - 1);
|
|
|
|
if (info && info->bl_dev) {
|
|
int i, max = 0;
|
|
|
|
/* Look for biggest value */
|
|
for (i = 0; i < FB_BACKLIGHT_LEVELS; i++)
|
|
max = max((int)info->bl_curve[i], max);
|
|
|
|
/* Look for nearest value */
|
|
for (i = 0; i < FB_BACKLIGHT_LEVELS; i++) {
|
|
int diff = abs(info->bl_curve[i] - value);
|
|
if (diff < max) {
|
|
max = diff;
|
|
level = i;
|
|
}
|
|
}
|
|
|
|
}
|
|
|
|
return level;
|
|
}
|
|
|
|
static void pmac_backlight_key(int direction)
|
|
{
|
|
mutex_lock(&pmac_backlight_mutex);
|
|
if (pmac_backlight) {
|
|
struct backlight_properties *props;
|
|
int brightness;
|
|
|
|
down(&pmac_backlight->sem);
|
|
props = pmac_backlight->props;
|
|
|
|
brightness = props->brightness +
|
|
((direction?-1:1) * (props->max_brightness / 15));
|
|
|
|
if (brightness < 0)
|
|
brightness = 0;
|
|
else if (brightness > props->max_brightness)
|
|
brightness = props->max_brightness;
|
|
|
|
props->brightness = brightness;
|
|
props->update_status(pmac_backlight);
|
|
|
|
up(&pmac_backlight->sem);
|
|
}
|
|
mutex_unlock(&pmac_backlight_mutex);
|
|
}
|
|
|
|
void pmac_backlight_key_up()
|
|
{
|
|
pmac_backlight_key(0);
|
|
}
|
|
|
|
void pmac_backlight_key_down()
|
|
{
|
|
pmac_backlight_key(1);
|
|
}
|
|
|
|
int pmac_backlight_set_legacy_brightness(int brightness)
|
|
{
|
|
int error = -ENXIO;
|
|
|
|
mutex_lock(&pmac_backlight_mutex);
|
|
if (pmac_backlight) {
|
|
struct backlight_properties *props;
|
|
|
|
down(&pmac_backlight->sem);
|
|
props = pmac_backlight->props;
|
|
props->brightness = brightness *
|
|
(props->max_brightness + 1) /
|
|
(OLD_BACKLIGHT_MAX + 1);
|
|
|
|
if (props->brightness > props->max_brightness)
|
|
props->brightness = props->max_brightness;
|
|
else if (props->brightness < 0)
|
|
props->brightness = 0;
|
|
|
|
props->update_status(pmac_backlight);
|
|
up(&pmac_backlight->sem);
|
|
|
|
error = 0;
|
|
}
|
|
mutex_unlock(&pmac_backlight_mutex);
|
|
|
|
return error;
|
|
}
|
|
|
|
int pmac_backlight_get_legacy_brightness()
|
|
{
|
|
int result = -ENXIO;
|
|
|
|
mutex_lock(&pmac_backlight_mutex);
|
|
if (pmac_backlight) {
|
|
struct backlight_properties *props;
|
|
|
|
down(&pmac_backlight->sem);
|
|
props = pmac_backlight->props;
|
|
|
|
result = props->brightness *
|
|
(OLD_BACKLIGHT_MAX + 1) /
|
|
(props->max_brightness + 1);
|
|
|
|
up(&pmac_backlight->sem);
|
|
}
|
|
mutex_unlock(&pmac_backlight_mutex);
|
|
|
|
return result;
|
|
}
|