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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 | // 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/backlight.h> #include <linux/pmu.h> #include <asm/backlight.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 = backlight_get_brightness(bd); 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); } |