1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Backlight code for nVidia based graphic cards 4 * 5 * Copyright 2004 Antonino Daplas <adaplas@pol.net> 6 * Copyright (c) 2006 Michael Hanselmann <linux-kernel@hansmi.ch> 7 */ 8 9 #include <linux/backlight.h> 10 #include <linux/fb.h> 11 #include <linux/pci.h> 12 13 #ifdef CONFIG_PMAC_BACKLIGHT 14 #include <asm/backlight.h> 15 #endif 16 17 #include "nv_local.h" 18 #include "nv_type.h" 19 #include "nv_proto.h" 20 21 /* We do not have any information about which values are allowed, thus 22 * we used safe values. 23 */ 24 #define MIN_LEVEL 0x158 25 #define MAX_LEVEL 0x534 26 #define LEVEL_STEP ((MAX_LEVEL - MIN_LEVEL) / FB_BACKLIGHT_MAX) 27 28 static int nvidia_bl_get_level_brightness(struct nvidia_par *par, 29 int level) 30 { 31 struct fb_info *info = pci_get_drvdata(par->pci_dev); 32 int nlevel; 33 34 /* Get and convert the value */ 35 /* No locking of bl_curve since we read a single value */ 36 nlevel = MIN_LEVEL + info->bl_curve[level] * LEVEL_STEP; 37 38 if (nlevel < 0) 39 nlevel = 0; 40 else if (nlevel < MIN_LEVEL) 41 nlevel = MIN_LEVEL; 42 else if (nlevel > MAX_LEVEL) 43 nlevel = MAX_LEVEL; 44 45 return nlevel; 46 } 47 48 static int nvidia_bl_update_status(struct backlight_device *bd) 49 { 50 struct nvidia_par *par = bl_get_data(bd); 51 u32 tmp_pcrt, tmp_pmc, fpcontrol; 52 int level = backlight_get_brightness(bd); 53 54 if (!par->FlatPanel) 55 return 0; 56 57 tmp_pmc = NV_RD32(par->PMC, 0x10F0) & 0x0000FFFF; 58 tmp_pcrt = NV_RD32(par->PCRTC0, 0x081C) & 0xFFFFFFFC; 59 fpcontrol = NV_RD32(par->PRAMDAC, 0x0848) & 0xCFFFFFCC; 60 61 if (level > 0) { 62 tmp_pcrt |= 0x1; 63 tmp_pmc |= (1 << 31); /* backlight bit */ 64 tmp_pmc |= nvidia_bl_get_level_brightness(par, level) << 16; 65 fpcontrol |= par->fpSyncs; 66 } else 67 fpcontrol |= 0x20000022; 68 69 NV_WR32(par->PCRTC0, 0x081C, tmp_pcrt); 70 NV_WR32(par->PMC, 0x10F0, tmp_pmc); 71 NV_WR32(par->PRAMDAC, 0x848, fpcontrol); 72 73 return 0; 74 } 75 76 static const struct backlight_ops nvidia_bl_ops = { 77 .update_status = nvidia_bl_update_status, 78 }; 79 80 void nvidia_bl_init(struct nvidia_par *par) 81 { 82 struct backlight_properties props; 83 struct fb_info *info = pci_get_drvdata(par->pci_dev); 84 struct backlight_device *bd; 85 char name[12]; 86 87 if (!par->FlatPanel) 88 return; 89 90 #ifdef CONFIG_PMAC_BACKLIGHT 91 if (!machine_is(powermac) || 92 !pmac_has_backlight_type("mnca")) 93 return; 94 #endif 95 96 snprintf(name, sizeof(name), "nvidiabl%d", info->node); 97 98 memset(&props, 0, sizeof(struct backlight_properties)); 99 props.type = BACKLIGHT_RAW; 100 props.max_brightness = FB_BACKLIGHT_LEVELS - 1; 101 bd = backlight_device_register(name, info->device, par, &nvidia_bl_ops, 102 &props); 103 if (IS_ERR(bd)) { 104 info->bl_dev = NULL; 105 printk(KERN_WARNING "nvidia: Backlight registration failed\n"); 106 goto error; 107 } 108 109 info->bl_dev = bd; 110 fb_bl_default_curve(info, 0, 111 0x158 * FB_BACKLIGHT_MAX / MAX_LEVEL, 112 0x534 * FB_BACKLIGHT_MAX / MAX_LEVEL); 113 114 bd->props.brightness = bd->props.max_brightness; 115 bd->props.power = FB_BLANK_UNBLANK; 116 backlight_update_status(bd); 117 118 printk("nvidia: Backlight initialized (%s)\n", name); 119 120 error: 121 return; 122 } 123 124 void nvidia_bl_exit(struct nvidia_par *par) 125 { 126 struct fb_info *info = pci_get_drvdata(par->pci_dev); 127 struct backlight_device *bd = info->bl_dev; 128 129 backlight_device_unregister(bd); 130 printk("nvidia: Backlight unloaded\n"); 131 } 132