drivers/video/backlight/mbp_nvidia_bl.c

   1 /*
   2  *  Backlight Driver for Nvidia 8600 in Macbook Pro
   3  *
   4  *  Copyright (c) Red Hat <mjg@redhat.com>
   5  *  Based on code from Pommed:
   6  *  Copyright (C) 2006 Nicolas Boichat <nicolas @boichat.ch>
   7  *  Copyright (C) 2006 Felipe Alfaro Solana <felipe_alfaro @linuxmail.org>
   8  *  Copyright (C) 2007 Julien BLACHE <jb@jblache.org>
   9  *
  10  *  This program is free software; you can redistribute it and/or modify
  11  *  it under the terms of the GNU General Public License version 2 as
  12  *  published by the Free Software Foundation.
  13  *
  14  *  This driver triggers SMIs which cause the firmware to change the
  15  *  backlight brightness. This is icky in many ways, but it's impractical to
  16  *  get at the firmware code in order to figure out what it's actually doing.
  17  */
  18
  19 #include <linux/module.h>
  20 #include <linux/kernel.h>
  21 #include <linux/init.h>
  22 #include <linux/platform_device.h>
  23 #include <linux/backlight.h>
  24 #include <linux/err.h>
  25 #include <linux/dmi.h>
  26 #include <linux/io.h>
  27
  28 static struct backlight_device *mbp_backlight_device;
  29
  30 /* Structure to be passed to the DMI_MATCH function. */
  31 struct dmi_match_data {
  32         /* I/O resource to allocate. */
  33         unsigned long iostart;
  34         unsigned long iolen;
  35         /* Backlight operations structure. */
  36         struct backlight_ops backlight_ops;
  37 };
  38
  39 /* Module parameters. */
  40 static int debug;
  41 module_param_named(debug, debug, int, 0644);
  42 MODULE_PARM_DESC(debug, "Set to one to enable debugging messages.");
  43
  44 /*
  45  * Implementation for MacBooks with Intel chipset.
  46  */
  47 static int intel_chipset_send_intensity(struct backlight_device *bd)
  48 {
  49         int intensity = bd->props.brightness;
  50
  51         if (debug)
  52                 printk(KERN_DEBUG "mbp_nvidia_bl: setting brightness to %d\n",
  53                        intensity);
  54
  55         outb(0x04 | (intensity << 4), 0xb3);
  56         outb(0xbf, 0xb2);
  57         return 0;
  58 }
  59
  60 static int intel_chipset_get_intensity(struct backlight_device *bd)
  61 {
  62         int intensity;
  63
  64         outb(0x03, 0xb3);
  65         outb(0xbf, 0xb2);
  66         intensity = inb(0xb3) >> 4;
  67
  68         if (debug)
  69                 printk(KERN_DEBUG "mbp_nvidia_bl: read brightness of %d\n",
  70                        intensity);
  71
  72         return intensity;
  73 }
  74
  75 static const struct dmi_match_data intel_chipset_data = {
  76         .iostart = 0xb2,
  77         .iolen = 2,
  78         .backlight_ops  = {
  79                 .options        = BL_CORE_SUSPENDRESUME,
  80                 .get_brightness = intel_chipset_get_intensity,
  81                 .update_status  = intel_chipset_send_intensity,
  82         }
  83 };
  84
  85 /*
  86  * Implementation for MacBooks with Nvidia chipset.
  87  */
  88 static int nvidia_chipset_send_intensity(struct backlight_device *bd)
  89 {
  90         int intensity = bd->props.brightness;
  91
  92         if (debug)
  93                 printk(KERN_DEBUG "mbp_nvidia_bl: setting brightness to %d\n",
  94                        intensity);
  95
  96         outb(0x04 | (intensity << 4), 0x52f);
  97         outb(0xbf, 0x52e);
  98         return 0;
  99 }
 100
 101 static int nvidia_chipset_get_intensity(struct backlight_device *bd)
 102 {
 103         int intensity;
 104
 105         outb(0x03, 0x52f);
 106         outb(0xbf, 0x52e);
 107         intensity = inb(0x52f) >> 4;
 108
 109         if (debug)
 110                 printk(KERN_DEBUG "mbp_nvidia_bl: read brightness of %d\n",
 111                        intensity);
 112
 113         return intensity;
 114 }
 115
 116 static const struct dmi_match_data nvidia_chipset_data = {
 117         .iostart = 0x52e,
 118         .iolen = 2,
 119         .backlight_ops          = {
 120                 .options        = BL_CORE_SUSPENDRESUME,
 121                 .get_brightness = nvidia_chipset_get_intensity,
 122                 .update_status  = nvidia_chipset_send_intensity
 123         }
 124 };
 125
 126 /*
 127  * DMI matching.
 128  */
 129 static /* const */ struct dmi_match_data *driver_data;
 130
 131 static int mbp_dmi_match(const struct dmi_system_id *id)
 132 {
 133         driver_data = id->driver_data;
 134
 135         printk(KERN_INFO "mbp_nvidia_bl: %s detected\n", id->ident);
 136         return 1;
 137 }
 138
 139 static const struct dmi_system_id __initdata mbp_device_table[] = {
 140         {
 141                 .callback       = mbp_dmi_match,
 142                 .ident          = "MacBookPro 3,1",
 143                 .matches        = {
 144                         DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
 145                         DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro3,1"),
 146                 },
 147                 .driver_data    = (void *)&intel_chipset_data,
 148         },
 149         {
 150                 .callback       = mbp_dmi_match,
 151                 .ident          = "MacBookPro 3,2",
 152                 .matches        = {
 153                         DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
 154                         DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro3,2"),
 155                 },
 156                 .driver_data    = (void *)&intel_chipset_data,
 157         },
 158         {
 159                 .callback       = mbp_dmi_match,
 160                 .ident          = "MacBookPro 4,1",
 161                 .matches        = {
 162                         DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
 163                         DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro4,1"),
 164                 },
 165                 .driver_data    = (void *)&intel_chipset_data,
 166         },
 167         {
 168                 .callback       = mbp_dmi_match,
 169                 .ident          = "MacBookAir 1,1",
 170                 .matches        = {
 171                         DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
 172                         DMI_MATCH(DMI_PRODUCT_NAME, "MacBookAir1,1"),
 173                 },
 174                 .driver_data    = (void *)&intel_chipset_data,
 175         },
 176         {
 177                 .callback       = mbp_dmi_match,
 178                 .ident          = "MacBook 5,1",
 179                 .matches        = {
 180                         DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
 181                         DMI_MATCH(DMI_PRODUCT_NAME, "MacBook5,1"),
 182                 },
 183                 .driver_data    = (void *)&nvidia_chipset_data,
 184         },
 185         {
 186                 .callback       = mbp_dmi_match,
 187                 .ident          = "MacBookAir 2,1",
 188                 .matches        = {
 189                         DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
 190                         DMI_MATCH(DMI_PRODUCT_NAME, "MacBookAir2,1"),
 191                 },
 192                 .driver_data    = (void *)&nvidia_chipset_data,
 193         },
 194         {
 195                 .callback       = mbp_dmi_match,
 196                 .ident          = "MacBookPro 5,1",
 197                 .matches        = {
 198                         DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
 199                         DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro5,1"),
 200                 },
 201                 .driver_data    = (void *)&nvidia_chipset_data,
 202         },
 203         { }
 204 };
 205
 206 static int __init mbp_init(void)
 207 {
 208         if (!dmi_check_system(mbp_device_table))
 209                 return -ENODEV;
 210
 211         if (!request_region(driver_data->iostart, driver_data->iolen,
 212                                                 "Macbook Pro backlight"))
 213                 return -ENXIO;
 214
 215         mbp_backlight_device = backlight_device_register("mbp_backlight",
 216                                         NULL, NULL, &driver_data->backlight_ops);
 217         if (IS_ERR(mbp_backlight_device)) {
 218                 release_region(driver_data->iostart, driver_data->iolen);
 219                 return PTR_ERR(mbp_backlight_device);
 220         }
 221
 222         mbp_backlight_device->props.max_brightness = 15;
 223         mbp_backlight_device->props.brightness =
 224                 driver_data->backlight_ops.get_brightness(mbp_backlight_device);
 225         backlight_update_status(mbp_backlight_device);
 226
 227         return 0;
 228 }
 229
 230 static void __exit mbp_exit(void)
 231 {
 232         backlight_device_unregister(mbp_backlight_device);
 233
 234         release_region(driver_data->iostart, driver_data->iolen);
 235 }
 236
 237 module_init(mbp_init);
 238 module_exit(mbp_exit);
 239
 240 MODULE_AUTHOR("Matthew Garrett <mjg@redhat.com>");
 241 MODULE_DESCRIPTION("Nvidia-based Macbook Pro Backlight Driver");
 242 MODULE_LICENSE("GPL");
 243 MODULE_DEVICE_TABLE(dmi, mbp_device_table);