linux/drivers/platform/x86/apple-gmux.c
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   1/*
   2 *  Gmux driver for Apple laptops
   3 *
   4 *  Copyright (C) Canonical Ltd. <seth.forshee@canonical.com>
   5 *  Copyright (C) 2010-2012 Andreas Heider <andreas@meetr.de>
   6 *
   7 *  This program is free software; you can redistribute it and/or modify
   8 *  it under the terms of the GNU General Public License version 2 as
   9 *  published by the Free Software Foundation.
  10 */
  11
  12#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  13
  14#include <linux/module.h>
  15#include <linux/kernel.h>
  16#include <linux/init.h>
  17#include <linux/backlight.h>
  18#include <linux/acpi.h>
  19#include <linux/pnp.h>
  20#include <linux/apple_bl.h>
  21#include <linux/slab.h>
  22#include <linux/delay.h>
  23#include <linux/pci.h>
  24#include <linux/vga_switcheroo.h>
  25#include <acpi/video.h>
  26#include <asm/io.h>
  27
  28struct apple_gmux_data {
  29        unsigned long iostart;
  30        unsigned long iolen;
  31        bool indexed;
  32        struct mutex index_lock;
  33
  34        struct backlight_device *bdev;
  35
  36        /* switcheroo data */
  37        acpi_handle dhandle;
  38        int gpe;
  39        enum vga_switcheroo_client_id resume_client_id;
  40        enum vga_switcheroo_state power_state;
  41        struct completion powerchange_done;
  42};
  43
  44static struct apple_gmux_data *apple_gmux_data;
  45
  46/*
  47 * gmux port offsets. Many of these are not yet used, but may be in the
  48 * future, and it's useful to have them documented here anyhow.
  49 */
  50#define GMUX_PORT_VERSION_MAJOR         0x04
  51#define GMUX_PORT_VERSION_MINOR         0x05
  52#define GMUX_PORT_VERSION_RELEASE       0x06
  53#define GMUX_PORT_SWITCH_DISPLAY        0x10
  54#define GMUX_PORT_SWITCH_GET_DISPLAY    0x11
  55#define GMUX_PORT_INTERRUPT_ENABLE      0x14
  56#define GMUX_PORT_INTERRUPT_STATUS      0x16
  57#define GMUX_PORT_SWITCH_DDC            0x28
  58#define GMUX_PORT_SWITCH_EXTERNAL       0x40
  59#define GMUX_PORT_SWITCH_GET_EXTERNAL   0x41
  60#define GMUX_PORT_DISCRETE_POWER        0x50
  61#define GMUX_PORT_MAX_BRIGHTNESS        0x70
  62#define GMUX_PORT_BRIGHTNESS            0x74
  63#define GMUX_PORT_VALUE                 0xc2
  64#define GMUX_PORT_READ                  0xd0
  65#define GMUX_PORT_WRITE                 0xd4
  66
  67#define GMUX_MIN_IO_LEN                 (GMUX_PORT_BRIGHTNESS + 4)
  68
  69#define GMUX_INTERRUPT_ENABLE           0xff
  70#define GMUX_INTERRUPT_DISABLE          0x00
  71
  72#define GMUX_INTERRUPT_STATUS_ACTIVE    0
  73#define GMUX_INTERRUPT_STATUS_DISPLAY   (1 << 0)
  74#define GMUX_INTERRUPT_STATUS_POWER     (1 << 2)
  75#define GMUX_INTERRUPT_STATUS_HOTPLUG   (1 << 3)
  76
  77#define GMUX_BRIGHTNESS_MASK            0x00ffffff
  78#define GMUX_MAX_BRIGHTNESS             GMUX_BRIGHTNESS_MASK
  79
  80static u8 gmux_pio_read8(struct apple_gmux_data *gmux_data, int port)
  81{
  82        return inb(gmux_data->iostart + port);
  83}
  84
  85static void gmux_pio_write8(struct apple_gmux_data *gmux_data, int port,
  86                               u8 val)
  87{
  88        outb(val, gmux_data->iostart + port);
  89}
  90
  91static u32 gmux_pio_read32(struct apple_gmux_data *gmux_data, int port)
  92{
  93        return inl(gmux_data->iostart + port);
  94}
  95
  96static void gmux_pio_write32(struct apple_gmux_data *gmux_data, int port,
  97                             u32 val)
  98{
  99        int i;
 100        u8 tmpval;
 101
 102        for (i = 0; i < 4; i++) {
 103                tmpval = (val >> (i * 8)) & 0xff;
 104                outb(tmpval, gmux_data->iostart + port + i);
 105        }
 106}
 107
 108static int gmux_index_wait_ready(struct apple_gmux_data *gmux_data)
 109{
 110        int i = 200;
 111        u8 gwr = inb(gmux_data->iostart + GMUX_PORT_WRITE);
 112
 113        while (i && (gwr & 0x01)) {
 114                inb(gmux_data->iostart + GMUX_PORT_READ);
 115                gwr = inb(gmux_data->iostart + GMUX_PORT_WRITE);
 116                udelay(100);
 117                i--;
 118        }
 119
 120        return !!i;
 121}
 122
 123static int gmux_index_wait_complete(struct apple_gmux_data *gmux_data)
 124{
 125        int i = 200;
 126        u8 gwr = inb(gmux_data->iostart + GMUX_PORT_WRITE);
 127
 128        while (i && !(gwr & 0x01)) {
 129                gwr = inb(gmux_data->iostart + GMUX_PORT_WRITE);
 130                udelay(100);
 131                i--;
 132        }
 133
 134        if (gwr & 0x01)
 135                inb(gmux_data->iostart + GMUX_PORT_READ);
 136
 137        return !!i;
 138}
 139
 140static u8 gmux_index_read8(struct apple_gmux_data *gmux_data, int port)
 141{
 142        u8 val;
 143
 144        mutex_lock(&gmux_data->index_lock);
 145        gmux_index_wait_ready(gmux_data);
 146        outb((port & 0xff), gmux_data->iostart + GMUX_PORT_READ);
 147        gmux_index_wait_complete(gmux_data);
 148        val = inb(gmux_data->iostart + GMUX_PORT_VALUE);
 149        mutex_unlock(&gmux_data->index_lock);
 150
 151        return val;
 152}
 153
 154static void gmux_index_write8(struct apple_gmux_data *gmux_data, int port,
 155                              u8 val)
 156{
 157        mutex_lock(&gmux_data->index_lock);
 158        outb(val, gmux_data->iostart + GMUX_PORT_VALUE);
 159        gmux_index_wait_ready(gmux_data);
 160        outb(port & 0xff, gmux_data->iostart + GMUX_PORT_WRITE);
 161        gmux_index_wait_complete(gmux_data);
 162        mutex_unlock(&gmux_data->index_lock);
 163}
 164
 165static u32 gmux_index_read32(struct apple_gmux_data *gmux_data, int port)
 166{
 167        u32 val;
 168
 169        mutex_lock(&gmux_data->index_lock);
 170        gmux_index_wait_ready(gmux_data);
 171        outb((port & 0xff), gmux_data->iostart + GMUX_PORT_READ);
 172        gmux_index_wait_complete(gmux_data);
 173        val = inl(gmux_data->iostart + GMUX_PORT_VALUE);
 174        mutex_unlock(&gmux_data->index_lock);
 175
 176        return val;
 177}
 178
 179static void gmux_index_write32(struct apple_gmux_data *gmux_data, int port,
 180                               u32 val)
 181{
 182        int i;
 183        u8 tmpval;
 184
 185        mutex_lock(&gmux_data->index_lock);
 186
 187        for (i = 0; i < 4; i++) {
 188                tmpval = (val >> (i * 8)) & 0xff;
 189                outb(tmpval, gmux_data->iostart + GMUX_PORT_VALUE + i);
 190        }
 191
 192        gmux_index_wait_ready(gmux_data);
 193        outb(port & 0xff, gmux_data->iostart + GMUX_PORT_WRITE);
 194        gmux_index_wait_complete(gmux_data);
 195        mutex_unlock(&gmux_data->index_lock);
 196}
 197
 198static u8 gmux_read8(struct apple_gmux_data *gmux_data, int port)
 199{
 200        if (gmux_data->indexed)
 201                return gmux_index_read8(gmux_data, port);
 202        else
 203                return gmux_pio_read8(gmux_data, port);
 204}
 205
 206static void gmux_write8(struct apple_gmux_data *gmux_data, int port, u8 val)
 207{
 208        if (gmux_data->indexed)
 209                gmux_index_write8(gmux_data, port, val);
 210        else
 211                gmux_pio_write8(gmux_data, port, val);
 212}
 213
 214static u32 gmux_read32(struct apple_gmux_data *gmux_data, int port)
 215{
 216        if (gmux_data->indexed)
 217                return gmux_index_read32(gmux_data, port);
 218        else
 219                return gmux_pio_read32(gmux_data, port);
 220}
 221
 222static void gmux_write32(struct apple_gmux_data *gmux_data, int port,
 223                             u32 val)
 224{
 225        if (gmux_data->indexed)
 226                gmux_index_write32(gmux_data, port, val);
 227        else
 228                gmux_pio_write32(gmux_data, port, val);
 229}
 230
 231static bool gmux_is_indexed(struct apple_gmux_data *gmux_data)
 232{
 233        u16 val;
 234
 235        outb(0xaa, gmux_data->iostart + 0xcc);
 236        outb(0x55, gmux_data->iostart + 0xcd);
 237        outb(0x00, gmux_data->iostart + 0xce);
 238
 239        val = inb(gmux_data->iostart + 0xcc) |
 240                (inb(gmux_data->iostart + 0xcd) << 8);
 241
 242        if (val == 0x55aa)
 243                return true;
 244
 245        return false;
 246}
 247
 248static int gmux_get_brightness(struct backlight_device *bd)
 249{
 250        struct apple_gmux_data *gmux_data = bl_get_data(bd);
 251        return gmux_read32(gmux_data, GMUX_PORT_BRIGHTNESS) &
 252               GMUX_BRIGHTNESS_MASK;
 253}
 254
 255static int gmux_update_status(struct backlight_device *bd)
 256{
 257        struct apple_gmux_data *gmux_data = bl_get_data(bd);
 258        u32 brightness = bd->props.brightness;
 259
 260        if (bd->props.state & BL_CORE_SUSPENDED)
 261                return 0;
 262
 263        gmux_write32(gmux_data, GMUX_PORT_BRIGHTNESS, brightness);
 264
 265        return 0;
 266}
 267
 268static const struct backlight_ops gmux_bl_ops = {
 269        .options = BL_CORE_SUSPENDRESUME,
 270        .get_brightness = gmux_get_brightness,
 271        .update_status = gmux_update_status,
 272};
 273
 274static int gmux_switchto(enum vga_switcheroo_client_id id)
 275{
 276        if (id == VGA_SWITCHEROO_IGD) {
 277                gmux_write8(apple_gmux_data, GMUX_PORT_SWITCH_DDC, 1);
 278                gmux_write8(apple_gmux_data, GMUX_PORT_SWITCH_DISPLAY, 2);
 279                gmux_write8(apple_gmux_data, GMUX_PORT_SWITCH_EXTERNAL, 2);
 280        } else {
 281                gmux_write8(apple_gmux_data, GMUX_PORT_SWITCH_DDC, 2);
 282                gmux_write8(apple_gmux_data, GMUX_PORT_SWITCH_DISPLAY, 3);
 283                gmux_write8(apple_gmux_data, GMUX_PORT_SWITCH_EXTERNAL, 3);
 284        }
 285
 286        return 0;
 287}
 288
 289static int gmux_set_discrete_state(struct apple_gmux_data *gmux_data,
 290                                   enum vga_switcheroo_state state)
 291{
 292        INIT_COMPLETION(gmux_data->powerchange_done);
 293
 294        if (state == VGA_SWITCHEROO_ON) {
 295                gmux_write8(gmux_data, GMUX_PORT_DISCRETE_POWER, 1);
 296                gmux_write8(gmux_data, GMUX_PORT_DISCRETE_POWER, 3);
 297                pr_debug("Discrete card powered up\n");
 298        } else {
 299                gmux_write8(gmux_data, GMUX_PORT_DISCRETE_POWER, 1);
 300                gmux_write8(gmux_data, GMUX_PORT_DISCRETE_POWER, 0);
 301                pr_debug("Discrete card powered down\n");
 302        }
 303
 304        gmux_data->power_state = state;
 305
 306        if (gmux_data->gpe >= 0 &&
 307            !wait_for_completion_interruptible_timeout(&gmux_data->powerchange_done,
 308                                                       msecs_to_jiffies(200)))
 309                pr_warn("Timeout waiting for gmux switch to complete\n");
 310
 311        return 0;
 312}
 313
 314static int gmux_set_power_state(enum vga_switcheroo_client_id id,
 315                                enum vga_switcheroo_state state)
 316{
 317        if (id == VGA_SWITCHEROO_IGD)
 318                return 0;
 319
 320        return gmux_set_discrete_state(apple_gmux_data, state);
 321}
 322
 323static int gmux_get_client_id(struct pci_dev *pdev)
 324{
 325        /*
 326         * Early Macbook Pros with switchable graphics use nvidia
 327         * integrated graphics. Hardcode that the 9400M is integrated.
 328         */
 329        if (pdev->vendor == PCI_VENDOR_ID_INTEL)
 330                return VGA_SWITCHEROO_IGD;
 331        else if (pdev->vendor == PCI_VENDOR_ID_NVIDIA &&
 332                 pdev->device == 0x0863)
 333                return VGA_SWITCHEROO_IGD;
 334        else
 335                return VGA_SWITCHEROO_DIS;
 336}
 337
 338static enum vga_switcheroo_client_id
 339gmux_active_client(struct apple_gmux_data *gmux_data)
 340{
 341        if (gmux_read8(gmux_data, GMUX_PORT_SWITCH_DISPLAY) == 2)
 342                return VGA_SWITCHEROO_IGD;
 343
 344        return VGA_SWITCHEROO_DIS;
 345}
 346
 347static struct vga_switcheroo_handler gmux_handler = {
 348        .switchto = gmux_switchto,
 349        .power_state = gmux_set_power_state,
 350        .get_client_id = gmux_get_client_id,
 351};
 352
 353static inline void gmux_disable_interrupts(struct apple_gmux_data *gmux_data)
 354{
 355        gmux_write8(gmux_data, GMUX_PORT_INTERRUPT_ENABLE,
 356                    GMUX_INTERRUPT_DISABLE);
 357}
 358
 359static inline void gmux_enable_interrupts(struct apple_gmux_data *gmux_data)
 360{
 361        gmux_write8(gmux_data, GMUX_PORT_INTERRUPT_ENABLE,
 362                    GMUX_INTERRUPT_ENABLE);
 363}
 364
 365static inline u8 gmux_interrupt_get_status(struct apple_gmux_data *gmux_data)
 366{
 367        return gmux_read8(gmux_data, GMUX_PORT_INTERRUPT_STATUS);
 368}
 369
 370static void gmux_clear_interrupts(struct apple_gmux_data *gmux_data)
 371{
 372        u8 status;
 373
 374        /* to clear interrupts write back current status */
 375        status = gmux_interrupt_get_status(gmux_data);
 376        gmux_write8(gmux_data, GMUX_PORT_INTERRUPT_STATUS, status);
 377}
 378
 379static void gmux_notify_handler(acpi_handle device, u32 value, void *context)
 380{
 381        u8 status;
 382        struct pnp_dev *pnp = (struct pnp_dev *)context;
 383        struct apple_gmux_data *gmux_data = pnp_get_drvdata(pnp);
 384
 385        status = gmux_interrupt_get_status(gmux_data);
 386        gmux_disable_interrupts(gmux_data);
 387        pr_debug("Notify handler called: status %d\n", status);
 388
 389        gmux_clear_interrupts(gmux_data);
 390        gmux_enable_interrupts(gmux_data);
 391
 392        if (status & GMUX_INTERRUPT_STATUS_POWER)
 393                complete(&gmux_data->powerchange_done);
 394}
 395
 396static int gmux_suspend(struct pnp_dev *pnp, pm_message_t state)
 397{
 398        struct apple_gmux_data *gmux_data = pnp_get_drvdata(pnp);
 399        gmux_data->resume_client_id = gmux_active_client(gmux_data);
 400        gmux_disable_interrupts(gmux_data);
 401        return 0;
 402}
 403
 404static int gmux_resume(struct pnp_dev *pnp)
 405{
 406        struct apple_gmux_data *gmux_data = pnp_get_drvdata(pnp);
 407        gmux_enable_interrupts(gmux_data);
 408        gmux_switchto(gmux_data->resume_client_id);
 409        if (gmux_data->power_state == VGA_SWITCHEROO_OFF)
 410                gmux_set_discrete_state(gmux_data, gmux_data->power_state);
 411        return 0;
 412}
 413
 414static int gmux_probe(struct pnp_dev *pnp, const struct pnp_device_id *id)
 415{
 416        struct apple_gmux_data *gmux_data;
 417        struct resource *res;
 418        struct backlight_properties props;
 419        struct backlight_device *bdev;
 420        u8 ver_major, ver_minor, ver_release;
 421        int ret = -ENXIO;
 422        acpi_status status;
 423        unsigned long long gpe;
 424
 425        if (apple_gmux_data)
 426                return -EBUSY;
 427
 428        gmux_data = kzalloc(sizeof(*gmux_data), GFP_KERNEL);
 429        if (!gmux_data)
 430                return -ENOMEM;
 431        pnp_set_drvdata(pnp, gmux_data);
 432
 433        res = pnp_get_resource(pnp, IORESOURCE_IO, 0);
 434        if (!res) {
 435                pr_err("Failed to find gmux I/O resource\n");
 436                goto err_free;
 437        }
 438
 439        gmux_data->iostart = res->start;
 440        gmux_data->iolen = res->end - res->start;
 441
 442        if (gmux_data->iolen < GMUX_MIN_IO_LEN) {
 443                pr_err("gmux I/O region too small (%lu < %u)\n",
 444                       gmux_data->iolen, GMUX_MIN_IO_LEN);
 445                goto err_free;
 446        }
 447
 448        if (!request_region(gmux_data->iostart, gmux_data->iolen,
 449                            "Apple gmux")) {
 450                pr_err("gmux I/O already in use\n");
 451                goto err_free;
 452        }
 453
 454        /*
 455         * Invalid version information may indicate either that the gmux
 456         * device isn't present or that it's a new one that uses indexed
 457         * io
 458         */
 459
 460        ver_major = gmux_read8(gmux_data, GMUX_PORT_VERSION_MAJOR);
 461        ver_minor = gmux_read8(gmux_data, GMUX_PORT_VERSION_MINOR);
 462        ver_release = gmux_read8(gmux_data, GMUX_PORT_VERSION_RELEASE);
 463        if (ver_major == 0xff && ver_minor == 0xff && ver_release == 0xff) {
 464                if (gmux_is_indexed(gmux_data)) {
 465                        u32 version;
 466                        mutex_init(&gmux_data->index_lock);
 467                        gmux_data->indexed = true;
 468                        version = gmux_read32(gmux_data,
 469                                GMUX_PORT_VERSION_MAJOR);
 470                        ver_major = (version >> 24) & 0xff;
 471                        ver_minor = (version >> 16) & 0xff;
 472                        ver_release = (version >> 8) & 0xff;
 473                } else {
 474                        pr_info("gmux device not present\n");
 475                        ret = -ENODEV;
 476                        goto err_release;
 477                }
 478        }
 479        pr_info("Found gmux version %d.%d.%d [%s]\n", ver_major, ver_minor,
 480                ver_release, (gmux_data->indexed ? "indexed" : "classic"));
 481
 482        memset(&props, 0, sizeof(props));
 483        props.type = BACKLIGHT_PLATFORM;
 484        props.max_brightness = gmux_read32(gmux_data, GMUX_PORT_MAX_BRIGHTNESS);
 485
 486        /*
 487         * Currently it's assumed that the maximum brightness is less than
 488         * 2^24 for compatibility with old gmux versions. Cap the max
 489         * brightness at this value, but print a warning if the hardware
 490         * reports something higher so that it can be fixed.
 491         */
 492        if (WARN_ON(props.max_brightness > GMUX_MAX_BRIGHTNESS))
 493                props.max_brightness = GMUX_MAX_BRIGHTNESS;
 494
 495        bdev = backlight_device_register("gmux_backlight", &pnp->dev,
 496                                         gmux_data, &gmux_bl_ops, &props);
 497        if (IS_ERR(bdev)) {
 498                ret = PTR_ERR(bdev);
 499                goto err_release;
 500        }
 501
 502        gmux_data->bdev = bdev;
 503        bdev->props.brightness = gmux_get_brightness(bdev);
 504        backlight_update_status(bdev);
 505
 506        /*
 507         * The backlight situation on Macs is complicated. If the gmux is
 508         * present it's the best choice, because it always works for
 509         * backlight control and supports more levels than other options.
 510         * Disable the other backlight choices.
 511         */
 512        acpi_video_dmi_promote_vendor();
 513        acpi_video_unregister();
 514        apple_bl_unregister();
 515
 516        gmux_data->power_state = VGA_SWITCHEROO_ON;
 517
 518        gmux_data->dhandle = DEVICE_ACPI_HANDLE(&pnp->dev);
 519        if (!gmux_data->dhandle) {
 520                pr_err("Cannot find acpi handle for pnp device %s\n",
 521                       dev_name(&pnp->dev));
 522                ret = -ENODEV;
 523                goto err_notify;
 524        }
 525
 526        status = acpi_evaluate_integer(gmux_data->dhandle, "GMGP", NULL, &gpe);
 527        if (ACPI_SUCCESS(status)) {
 528                gmux_data->gpe = (int)gpe;
 529
 530                status = acpi_install_notify_handler(gmux_data->dhandle,
 531                                                     ACPI_DEVICE_NOTIFY,
 532                                                     &gmux_notify_handler, pnp);
 533                if (ACPI_FAILURE(status)) {
 534                        pr_err("Install notify handler failed: %s\n",
 535                               acpi_format_exception(status));
 536                        ret = -ENODEV;
 537                        goto err_notify;
 538                }
 539
 540                status = acpi_enable_gpe(NULL, gmux_data->gpe);
 541                if (ACPI_FAILURE(status)) {
 542                        pr_err("Cannot enable gpe: %s\n",
 543                               acpi_format_exception(status));
 544                        goto err_enable_gpe;
 545                }
 546        } else {
 547                pr_warn("No GPE found for gmux\n");
 548                gmux_data->gpe = -1;
 549        }
 550
 551        if (vga_switcheroo_register_handler(&gmux_handler)) {
 552                ret = -ENODEV;
 553                goto err_register_handler;
 554        }
 555
 556        init_completion(&gmux_data->powerchange_done);
 557        apple_gmux_data = gmux_data;
 558        gmux_enable_interrupts(gmux_data);
 559
 560        return 0;
 561
 562err_register_handler:
 563        if (gmux_data->gpe >= 0)
 564                acpi_disable_gpe(NULL, gmux_data->gpe);
 565err_enable_gpe:
 566        if (gmux_data->gpe >= 0)
 567                acpi_remove_notify_handler(gmux_data->dhandle,
 568                                           ACPI_DEVICE_NOTIFY,
 569                                           &gmux_notify_handler);
 570err_notify:
 571        backlight_device_unregister(bdev);
 572err_release:
 573        release_region(gmux_data->iostart, gmux_data->iolen);
 574err_free:
 575        kfree(gmux_data);
 576        return ret;
 577}
 578
 579static void gmux_remove(struct pnp_dev *pnp)
 580{
 581        struct apple_gmux_data *gmux_data = pnp_get_drvdata(pnp);
 582
 583        vga_switcheroo_unregister_handler();
 584        gmux_disable_interrupts(gmux_data);
 585        if (gmux_data->gpe >= 0) {
 586                acpi_disable_gpe(NULL, gmux_data->gpe);
 587                acpi_remove_notify_handler(gmux_data->dhandle,
 588                                           ACPI_DEVICE_NOTIFY,
 589                                           &gmux_notify_handler);
 590        }
 591
 592        backlight_device_unregister(gmux_data->bdev);
 593
 594        release_region(gmux_data->iostart, gmux_data->iolen);
 595        apple_gmux_data = NULL;
 596        kfree(gmux_data);
 597
 598        acpi_video_dmi_demote_vendor();
 599        acpi_video_register();
 600        apple_bl_register();
 601}
 602
 603static const struct pnp_device_id gmux_device_ids[] = {
 604        {"APP000B", 0},
 605        {"", 0}
 606};
 607
 608static struct pnp_driver gmux_pnp_driver = {
 609        .name           = "apple-gmux",
 610        .probe          = gmux_probe,
 611        .remove         = gmux_remove,
 612        .id_table       = gmux_device_ids,
 613        .suspend        = gmux_suspend,
 614        .resume         = gmux_resume
 615};
 616
 617static int __init apple_gmux_init(void)
 618{
 619        return pnp_register_driver(&gmux_pnp_driver);
 620}
 621
 622static void __exit apple_gmux_exit(void)
 623{
 624        pnp_unregister_driver(&gmux_pnp_driver);
 625}
 626
 627module_init(apple_gmux_init);
 628module_exit(apple_gmux_exit);
 629
 630MODULE_AUTHOR("Seth Forshee <seth.forshee@canonical.com>");
 631MODULE_DESCRIPTION("Apple Gmux Driver");
 632MODULE_LICENSE("GPL");
 633MODULE_DEVICE_TABLE(pnp, gmux_device_ids);
 634