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linux-next/drivers/macintosh/via-pmu-backlight.c
Richard Purdie 599a52d126 backlight: Separate backlight properties from backlight ops pointers
Per device data such as brightness belongs to the indivdual device
and should therefore be separate from the the backlight operation
function pointers. This patch splits the two types of data and
allows simplifcation of some code.

Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
2007-02-20 09:26:53 +00:00

181 lines
4.0 KiB
C

/*
* Backlight code for via-pmu
*
* Copyright (C) 1998 Paul Mackerras and Fabio Riccardi.
* Copyright (C) 2001-2002 Benjamin Herrenschmidt
* Copyright (C) 2006 Michael Hanselmann <linux-kernel@hansmi.ch>
*
*/
#include <asm/ptrace.h>
#include <linux/adb.h>
#include <linux/pmu.h>
#include <asm/backlight.h>
#include <asm/prom.h>
#define MAX_PMU_LEVEL 0xFF
static struct backlight_ops pmu_backlight_data;
static DEFINE_SPINLOCK(pmu_backlight_lock);
static int sleeping;
static u8 bl_curve[FB_BACKLIGHT_LEVELS];
static void pmu_backlight_init_curve(u8 off, u8 min, u8 max)
{
unsigned int i, flat, count, range = (max - min);
bl_curve[0] = off;
for (flat = 1; flat < (FB_BACKLIGHT_LEVELS / 16); ++flat)
bl_curve[flat] = min;
count = FB_BACKLIGHT_LEVELS * 15 / 16;
for (i = 0; i < count; ++i)
bl_curve[flat + i] = min + (range * (i + 1) / count);
}
static int pmu_backlight_curve_lookup(int value)
{
int level = (FB_BACKLIGHT_LEVELS - 1);
int i, max = 0;
/* Look for biggest value */
for (i = 0; i < FB_BACKLIGHT_LEVELS; i++)
max = max((int)bl_curve[i], max);
/* Look for nearest value */
for (i = 0; i < FB_BACKLIGHT_LEVELS; i++) {
int diff = abs(bl_curve[i] - value);
if (diff < max) {
max = diff;
level = i;
}
}
return level;
}
static int pmu_backlight_get_level_brightness(int level)
{
int pmulevel;
/* Get and convert the value */
pmulevel = bl_curve[level] * FB_BACKLIGHT_MAX / MAX_PMU_LEVEL;
if (pmulevel < 0)
pmulevel = 0;
else if (pmulevel > MAX_PMU_LEVEL)
pmulevel = MAX_PMU_LEVEL;
return pmulevel;
}
static int pmu_backlight_update_status(struct backlight_device *bd)
{
struct adb_request req;
unsigned long flags;
int level = bd->props.brightness;
spin_lock_irqsave(&pmu_backlight_lock, flags);
/* Don't update brightness when sleeping */
if (sleeping)
goto out;
if (bd->props.power != FB_BLANK_UNBLANK ||
bd->props.fb_blank != FB_BLANK_UNBLANK)
level = 0;
if (level > 0) {
int pmulevel = pmu_backlight_get_level_brightness(level);
pmu_request(&req, NULL, 2, PMU_BACKLIGHT_BRIGHT, pmulevel);
pmu_wait_complete(&req);
pmu_request(&req, NULL, 2, PMU_POWER_CTRL,
PMU_POW_BACKLIGHT | PMU_POW_ON);
pmu_wait_complete(&req);
} else {
pmu_request(&req, NULL, 2, PMU_POWER_CTRL,
PMU_POW_BACKLIGHT | PMU_POW_OFF);
pmu_wait_complete(&req);
}
out:
spin_unlock_irqrestore(&pmu_backlight_lock, flags);
return 0;
}
static int pmu_backlight_get_brightness(struct backlight_device *bd)
{
return bd->props.brightness;
}
static struct backlight_ops pmu_backlight_data = {
.get_brightness = pmu_backlight_get_brightness,
.update_status = pmu_backlight_update_status,
};
#ifdef CONFIG_PM
void pmu_backlight_set_sleep(int sleep)
{
unsigned long flags;
spin_lock_irqsave(&pmu_backlight_lock, flags);
sleeping = sleep;
spin_unlock_irqrestore(&pmu_backlight_lock, flags);
}
#endif /* CONFIG_PM */
void __init pmu_backlight_init()
{
struct backlight_device *bd;
char name[10];
int level, autosave;
/* Special case for the old PowerBook since I can't test on it */
autosave =
machine_is_compatible("AAPL,3400/2400") ||
machine_is_compatible("AAPL,3500");
if (!autosave &&
!pmac_has_backlight_type("pmu") &&
!machine_is_compatible("AAPL,PowerBook1998") &&
!machine_is_compatible("PowerBook1,1"))
return;
snprintf(name, sizeof(name), "pmubl");
bd = backlight_device_register(name, NULL, NULL, &pmu_backlight_data);
if (IS_ERR(bd)) {
printk("pmubl: Backlight registration failed\n");
goto error;
}
bd->props.max_brightness = FB_BACKLIGHT_LEVELS - 1;
pmu_backlight_init_curve(0x7F, 0x46, 0x0E);
level = bd->props.max_brightness;
if (autosave) {
/* read autosaved value if available */
struct adb_request req;
pmu_request(&req, NULL, 2, 0xd9, 0);
pmu_wait_complete(&req);
level = pmu_backlight_curve_lookup(
(req.reply[0] >> 4) *
bd->props.max_brightness / 15);
}
bd->props.brightness = level;
bd->props.power = FB_BLANK_UNBLANK;
backlight_update_status(bd);
printk("pmubl: Backlight initialized (%s)\n", name);
return;
error:
return;
}