/* * 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; }