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linux-next/drivers/macintosh/via-pmu-backlight.c
Michael Hanselmann 5474c120aa [PATCH] Rewritten backlight infrastructure for portable Apple computers
This patch contains a total rewrite of the backlight infrastructure for
portable Apple computers.  Backward compatibility is retained.  A sysfs
interface allows userland to control the brightness with more steps than
before.  Userland is allowed to upload a brightness curve for different
monitors, similar to Mac OS X.

[akpm@osdl.org: add needed exports]
Signed-off-by: Michael Hanselmann <linux-kernel@hansmi.ch>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-25 10:00:59 -07:00

151 lines
3.5 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 device_node *vias;
static struct backlight_properties pmu_backlight_data;
static int pmu_backlight_get_level_brightness(struct fb_info *info,
int level)
{
int pmulevel;
/* Get and convert the value */
mutex_lock(&info->bl_mutex);
pmulevel = info->bl_curve[level] * FB_BACKLIGHT_MAX / MAX_PMU_LEVEL;
mutex_unlock(&info->bl_mutex);
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 fb_info *info = class_get_devdata(&bd->class_dev);
struct adb_request req;
int pmulevel, level = bd->props->brightness;
if (vias == NULL)
return -ENODEV;
if (bd->props->power != FB_BLANK_UNBLANK ||
bd->props->fb_blank != FB_BLANK_UNBLANK)
level = 0;
pmulevel = pmu_backlight_get_level_brightness(info, 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 | (level > 0 ? PMU_POW_ON : PMU_POW_OFF));
pmu_wait_complete(&req);
return 0;
}
static int pmu_backlight_get_brightness(struct backlight_device *bd)
{
return bd->props->brightness;
}
static struct backlight_properties pmu_backlight_data = {
.owner = THIS_MODULE,
.get_brightness = pmu_backlight_get_brightness,
.update_status = pmu_backlight_update_status,
.max_brightness = (FB_BACKLIGHT_LEVELS - 1),
};
void __init pmu_backlight_init(struct device_node *in_vias)
{
struct backlight_device *bd;
struct fb_info *info;
char name[10];
int level, autosave;
vias = in_vias;
/* 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;
/* Actually, this is a hack, but I don't know of a better way
* to get the first framebuffer device.
*/
info = registered_fb[0];
if (!info) {
printk("pmubl: No framebuffer found\n");
goto error;
}
snprintf(name, sizeof(name), "pmubl%d", info->node);
bd = backlight_device_register(name, info, &pmu_backlight_data);
if (IS_ERR(bd)) {
printk("pmubl: Backlight registration failed\n");
goto error;
}
mutex_lock(&info->bl_mutex);
info->bl_dev = bd;
fb_bl_default_curve(info, 0x7F, 0x46, 0x0E);
mutex_unlock(&info->bl_mutex);
level = pmu_backlight_data.max_brightness;
if (autosave) {
/* read autosaved value if available */
struct adb_request req;
pmu_request(&req, NULL, 2, 0xd9, 0);
pmu_wait_complete(&req);
mutex_lock(&info->bl_mutex);
level = pmac_backlight_curve_lookup(info,
(req.reply[0] >> 4) *
pmu_backlight_data.max_brightness / 15);
mutex_unlock(&info->bl_mutex);
}
up(&bd->sem);
bd->props->brightness = level;
bd->props->power = FB_BLANK_UNBLANK;
bd->props->update_status(bd);
down(&bd->sem);
mutex_lock(&pmac_backlight_mutex);
if (!pmac_backlight)
pmac_backlight = bd;
mutex_unlock(&pmac_backlight_mutex);
printk("pmubl: Backlight initialized (%s)\n", name);
return;
error:
return;
}