diff options
Diffstat (limited to 'drivers/macintosh/via-pmu-backlight.c')
| -rw-r--r-- | drivers/macintosh/via-pmu-backlight.c | 190 |
1 files changed, 190 insertions, 0 deletions
diff --git a/drivers/macintosh/via-pmu-backlight.c b/drivers/macintosh/via-pmu-backlight.c new file mode 100644 index 000000000..50ada02ae --- /dev/null +++ b/drivers/macintosh/via-pmu-backlight.c @@ -0,0 +1,190 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * 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 const struct backlight_ops pmu_backlight_data; +static DEFINE_SPINLOCK(pmu_backlight_lock); +static int sleeping, uses_pmu_bl; +static u8 bl_curve[FB_BACKLIGHT_LEVELS]; + +static void pmu_backlight_init_curve(u8 off, u8 min, u8 max) +{ + 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; + int level = bd->props.brightness; + + + 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); + } + + return 0; +} + +static int pmu_backlight_update_status(struct backlight_device *bd) +{ + unsigned long flags; + int rc = 0; + + spin_lock_irqsave(&pmu_backlight_lock, flags); + /* Don't update brightness when sleeping */ + if (!sleeping) + rc = __pmu_backlight_update_status(bd); + spin_unlock_irqrestore(&pmu_backlight_lock, flags); + return rc; +} + + +static const struct backlight_ops pmu_backlight_data = { + .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; + if (pmac_backlight && uses_pmu_bl) { + if (sleep) { + struct adb_request req; + + pmu_request(&req, NULL, 2, PMU_POWER_CTRL, + PMU_POW_BACKLIGHT | PMU_POW_OFF); + pmu_wait_complete(&req); + } else + __pmu_backlight_update_status(pmac_backlight); + } + spin_unlock_irqrestore(&pmu_backlight_lock, flags); +} +#endif /* CONFIG_PM */ + +void __init pmu_backlight_init(void) +{ + struct backlight_properties props; + struct backlight_device *bd; + char name[10]; + int level, autosave; + + /* Special case for the old PowerBook since I can't test on it */ + autosave = + of_machine_is_compatible("AAPL,3400/2400") || + of_machine_is_compatible("AAPL,3500"); + + if (!autosave && + !pmac_has_backlight_type("pmu") && + !of_machine_is_compatible("AAPL,PowerBook1998") && + !of_machine_is_compatible("PowerBook1,1")) + return; + + snprintf(name, sizeof(name), "pmubl"); + + memset(&props, 0, sizeof(struct backlight_properties)); + props.type = BACKLIGHT_PLATFORM; + props.max_brightness = FB_BACKLIGHT_LEVELS - 1; + bd = backlight_device_register(name, NULL, NULL, &pmu_backlight_data, + &props); + if (IS_ERR(bd)) { + printk(KERN_ERR "PMU Backlight registration failed\n"); + return; + } + uses_pmu_bl = 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(KERN_INFO "PMU Backlight initialized (%s)\n", name); +} |