1/* 2 * Backlight code for via-pmu 3 * 4 * Copyright (C) 1998 Paul Mackerras and Fabio Riccardi. 5 * Copyright (C) 2001-2002 Benjamin Herrenschmidt 6 * Copyright (C) 2006 Michael Hanselmann <linux-kernel@hansmi.ch> 7 * 8 */ 9 10#include <asm/ptrace.h> 11#include <linux/adb.h> 12#include <linux/pmu.h> 13#include <asm/backlight.h> 14#include <asm/prom.h> 15 16#define MAX_PMU_LEVEL 0xFF 17 18static struct backlight_ops pmu_backlight_data; 19static DEFINE_SPINLOCK(pmu_backlight_lock); 20static int sleeping, uses_pmu_bl; 21static u8 bl_curve[FB_BACKLIGHT_LEVELS]; 22 23static void pmu_backlight_init_curve(u8 off, u8 min, u8 max) 24{ 25 int i, flat, count, range = (max - min); 26 27 bl_curve[0] = off; 28 29 for (flat = 1; flat < (FB_BACKLIGHT_LEVELS / 16); ++flat) 30 bl_curve[flat] = min; 31 32 count = FB_BACKLIGHT_LEVELS * 15 / 16; 33 for (i = 0; i < count; ++i) 34 bl_curve[flat + i] = min + (range * (i + 1) / count); 35} 36 37static int pmu_backlight_curve_lookup(int value) 38{ 39 int level = (FB_BACKLIGHT_LEVELS - 1); 40 int i, max = 0; 41 42 /* Look for biggest value */ 43 for (i = 0; i < FB_BACKLIGHT_LEVELS; i++) 44 max = max((int)bl_curve[i], max); 45 46 /* Look for nearest value */ 47 for (i = 0; i < FB_BACKLIGHT_LEVELS; i++) { 48 int diff = abs(bl_curve[i] - value); 49 if (diff < max) { 50 max = diff; 51 level = i; 52 } 53 } 54 return level; 55} 56 57static int pmu_backlight_get_level_brightness(int level) 58{ 59 int pmulevel; 60 61 /* Get and convert the value */ 62 pmulevel = bl_curve[level] * FB_BACKLIGHT_MAX / MAX_PMU_LEVEL; 63 if (pmulevel < 0) 64 pmulevel = 0; 65 else if (pmulevel > MAX_PMU_LEVEL) 66 pmulevel = MAX_PMU_LEVEL; 67 68 return pmulevel; 69} 70 71static int __pmu_backlight_update_status(struct backlight_device *bd) 72{ 73 struct adb_request req; 74 int level = bd->props.brightness; 75 76 77 if (bd->props.power != FB_BLANK_UNBLANK || 78 bd->props.fb_blank != FB_BLANK_UNBLANK) 79 level = 0; 80 81 if (level > 0) { 82 int pmulevel = pmu_backlight_get_level_brightness(level); 83 84 pmu_request(&req, NULL, 2, PMU_BACKLIGHT_BRIGHT, pmulevel); 85 pmu_wait_complete(&req); 86 87 pmu_request(&req, NULL, 2, PMU_POWER_CTRL, 88 PMU_POW_BACKLIGHT | PMU_POW_ON); 89 pmu_wait_complete(&req); 90 } else { 91 pmu_request(&req, NULL, 2, PMU_POWER_CTRL, 92 PMU_POW_BACKLIGHT | PMU_POW_OFF); 93 pmu_wait_complete(&req); 94 } 95 96 return 0; 97} 98 99static int pmu_backlight_update_status(struct backlight_device *bd) 100{ 101 unsigned long flags; 102 int rc = 0; 103 104 spin_lock_irqsave(&pmu_backlight_lock, flags); 105 /* Don't update brightness when sleeping */ 106 if (!sleeping) 107 rc = __pmu_backlight_update_status(bd); 108 spin_unlock_irqrestore(&pmu_backlight_lock, flags); 109 return rc; 110} 111 112 113static int pmu_backlight_get_brightness(struct backlight_device *bd) 114{ 115 return bd->props.brightness; 116} 117 118static struct backlight_ops pmu_backlight_data = { 119 .get_brightness = pmu_backlight_get_brightness, 120 .update_status = pmu_backlight_update_status, 121 122}; 123 124#ifdef CONFIG_PM 125void pmu_backlight_set_sleep(int sleep) 126{ 127 unsigned long flags; 128 129 spin_lock_irqsave(&pmu_backlight_lock, flags); 130 sleeping = sleep; 131 if (pmac_backlight && uses_pmu_bl) { 132 if (sleep) { 133 struct adb_request req; 134 135 pmu_request(&req, NULL, 2, PMU_POWER_CTRL, 136 PMU_POW_BACKLIGHT | PMU_POW_OFF); 137 pmu_wait_complete(&req); 138 } else 139 __pmu_backlight_update_status(pmac_backlight); 140 } 141 spin_unlock_irqrestore(&pmu_backlight_lock, flags); 142} 143#endif /* CONFIG_PM */ 144 145void __init pmu_backlight_init() 146{ 147 struct backlight_properties props; 148 struct backlight_device *bd; 149 char name[10]; 150 int level, autosave; 151 152 /* Special case for the old PowerBook since I can't test on it */ 153 autosave = 154 of_machine_is_compatible("AAPL,3400/2400") || 155 of_machine_is_compatible("AAPL,3500"); 156 157 if (!autosave && 158 !pmac_has_backlight_type("pmu") && 159 !of_machine_is_compatible("AAPL,PowerBook1998") && 160 !of_machine_is_compatible("PowerBook1,1")) 161 return; 162 163 snprintf(name, sizeof(name), "pmubl"); 164 165 memset(&props, 0, sizeof(struct backlight_properties)); 166 props.max_brightness = FB_BACKLIGHT_LEVELS - 1; 167 bd = backlight_device_register(name, NULL, NULL, &pmu_backlight_data, 168 &props); 169 if (IS_ERR(bd)) { 170 printk(KERN_ERR "PMU Backlight registration failed\n"); 171 return; 172 } 173 uses_pmu_bl = 1; 174 pmu_backlight_init_curve(0x7F, 0x46, 0x0E); 175 176 level = bd->props.max_brightness; 177 178 if (autosave) { 179 /* read autosaved value if available */ 180 struct adb_request req; 181 pmu_request(&req, NULL, 2, 0xd9, 0); 182 pmu_wait_complete(&req); 183 184 level = pmu_backlight_curve_lookup( 185 (req.reply[0] >> 4) * 186 bd->props.max_brightness / 15); 187 } 188 189 bd->props.brightness = level; 190 bd->props.power = FB_BLANK_UNBLANK; 191 backlight_update_status(bd); 192 193 printk(KERN_INFO "PMU Backlight initialized (%s)\n", name); 194} 195