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![Benjamin Herrenschmidt](/assets/img/avatar_default.png)
The PMU backlight code would kick in during sleep/resume even on machines that use a different backlight method. This breaks sleep on some PowerBooks. This fixes it by adding a flag to indicate whether the backlight is controlled by the PMU, and testing that before trying to use the PMU to turn off the backlight during sleep. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
191 lines
4.4 KiB
C
191 lines
4.4 KiB
C
/*
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* Backlight code for via-pmu
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*
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* Copyright (C) 1998 Paul Mackerras and Fabio Riccardi.
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* Copyright (C) 2001-2002 Benjamin Herrenschmidt
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* Copyright (C) 2006 Michael Hanselmann <linux-kernel@hansmi.ch>
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*
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*/
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#include <asm/ptrace.h>
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#include <linux/adb.h>
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#include <linux/pmu.h>
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#include <asm/backlight.h>
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#include <asm/prom.h>
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#define MAX_PMU_LEVEL 0xFF
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static struct backlight_ops pmu_backlight_data;
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static DEFINE_SPINLOCK(pmu_backlight_lock);
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static int sleeping, uses_pmu_bl;
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static u8 bl_curve[FB_BACKLIGHT_LEVELS];
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static void pmu_backlight_init_curve(u8 off, u8 min, u8 max)
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{
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int i, flat, count, range = (max - min);
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bl_curve[0] = off;
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for (flat = 1; flat < (FB_BACKLIGHT_LEVELS / 16); ++flat)
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bl_curve[flat] = min;
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count = FB_BACKLIGHT_LEVELS * 15 / 16;
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for (i = 0; i < count; ++i)
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bl_curve[flat + i] = min + (range * (i + 1) / count);
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}
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static int pmu_backlight_curve_lookup(int value)
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{
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int level = (FB_BACKLIGHT_LEVELS - 1);
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int i, max = 0;
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/* Look for biggest value */
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for (i = 0; i < FB_BACKLIGHT_LEVELS; i++)
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max = max((int)bl_curve[i], max);
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/* Look for nearest value */
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for (i = 0; i < FB_BACKLIGHT_LEVELS; i++) {
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int diff = abs(bl_curve[i] - value);
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if (diff < max) {
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max = diff;
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level = i;
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}
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}
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return level;
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}
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static int pmu_backlight_get_level_brightness(int level)
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{
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int pmulevel;
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/* Get and convert the value */
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pmulevel = bl_curve[level] * FB_BACKLIGHT_MAX / MAX_PMU_LEVEL;
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if (pmulevel < 0)
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pmulevel = 0;
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else if (pmulevel > MAX_PMU_LEVEL)
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pmulevel = MAX_PMU_LEVEL;
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return pmulevel;
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}
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static int __pmu_backlight_update_status(struct backlight_device *bd)
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{
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struct adb_request req;
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int level = bd->props.brightness;
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if (bd->props.power != FB_BLANK_UNBLANK ||
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bd->props.fb_blank != FB_BLANK_UNBLANK)
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level = 0;
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if (level > 0) {
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int pmulevel = pmu_backlight_get_level_brightness(level);
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pmu_request(&req, NULL, 2, PMU_BACKLIGHT_BRIGHT, pmulevel);
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pmu_wait_complete(&req);
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pmu_request(&req, NULL, 2, PMU_POWER_CTRL,
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PMU_POW_BACKLIGHT | PMU_POW_ON);
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pmu_wait_complete(&req);
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} else {
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pmu_request(&req, NULL, 2, PMU_POWER_CTRL,
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PMU_POW_BACKLIGHT | PMU_POW_OFF);
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pmu_wait_complete(&req);
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}
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return 0;
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}
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static int pmu_backlight_update_status(struct backlight_device *bd)
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{
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unsigned long flags;
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int rc = 0;
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spin_lock_irqsave(&pmu_backlight_lock, flags);
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/* Don't update brightness when sleeping */
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if (!sleeping)
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rc = __pmu_backlight_update_status(bd);
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spin_unlock_irqrestore(&pmu_backlight_lock, flags);
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return rc;
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}
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static int pmu_backlight_get_brightness(struct backlight_device *bd)
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{
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return bd->props.brightness;
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}
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static struct backlight_ops pmu_backlight_data = {
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.get_brightness = pmu_backlight_get_brightness,
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.update_status = pmu_backlight_update_status,
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};
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#ifdef CONFIG_PM
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void pmu_backlight_set_sleep(int sleep)
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{
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unsigned long flags;
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spin_lock_irqsave(&pmu_backlight_lock, flags);
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sleeping = sleep;
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if (pmac_backlight && uses_pmu_bl) {
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if (sleep) {
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struct adb_request req;
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pmu_request(&req, NULL, 2, PMU_POWER_CTRL,
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PMU_POW_BACKLIGHT | PMU_POW_OFF);
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pmu_wait_complete(&req);
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} else
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__pmu_backlight_update_status(pmac_backlight);
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}
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spin_unlock_irqrestore(&pmu_backlight_lock, flags);
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}
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#endif /* CONFIG_PM */
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void __init pmu_backlight_init()
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{
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struct backlight_device *bd;
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char name[10];
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int level, autosave;
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/* Special case for the old PowerBook since I can't test on it */
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autosave =
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machine_is_compatible("AAPL,3400/2400") ||
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machine_is_compatible("AAPL,3500");
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if (!autosave &&
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!pmac_has_backlight_type("pmu") &&
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!machine_is_compatible("AAPL,PowerBook1998") &&
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!machine_is_compatible("PowerBook1,1"))
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return;
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snprintf(name, sizeof(name), "pmubl");
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bd = backlight_device_register(name, NULL, NULL, &pmu_backlight_data);
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if (IS_ERR(bd)) {
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printk(KERN_ERR "PMU Backlight registration failed\n");
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return;
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}
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uses_pmu_bl = 1;
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bd->props.max_brightness = FB_BACKLIGHT_LEVELS - 1;
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pmu_backlight_init_curve(0x7F, 0x46, 0x0E);
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level = bd->props.max_brightness;
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if (autosave) {
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/* read autosaved value if available */
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struct adb_request req;
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pmu_request(&req, NULL, 2, 0xd9, 0);
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pmu_wait_complete(&req);
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level = pmu_backlight_curve_lookup(
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(req.reply[0] >> 4) *
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bd->props.max_brightness / 15);
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}
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bd->props.brightness = level;
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bd->props.power = FB_BLANK_UNBLANK;
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backlight_update_status(bd);
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printk(KERN_INFO "PMU Backlight initialized (%s)\n", name);
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}
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