drivers/platform/x86/apple-gmux.c

   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  *  Copyright (C) 2015 Lukas Wunner <lukas@wunner.de>
   7  *
   8  *  This program is free software; you can redistribute it and/or modify
   9  *  it under the terms of the GNU General Public License version 2 as
  10  *  published by the Free Software Foundation.
  11  */
  12
  13 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  14
  15 #include <linux/module.h>
  16 #include <linux/kernel.h>
  17 #include <linux/init.h>
  18 #include <linux/backlight.h>
  19 #include <linux/acpi.h>
  20 #include <linux/pnp.h>
  21 #include <linux/apple_bl.h>
  22 #include <linux/apple-gmux.h>
  23 #include <linux/slab.h>
  24 #include <linux/delay.h>
  25 #include <linux/pci.h>
  26 #include <linux/vga_switcheroo.h>
  27 #include <linux/vgaarb.h>
  28 #include <acpi/video.h>
  29 #include <asm/io.h>
  30
  31 /**
  32  * DOC: Overview
  33  *
  34  * :1:  http://www.latticesemi.com/en/Products/FPGAandCPLD/LatticeXP2.aspx
  35  * :2:  http://www.renesas.com/products/mpumcu/h8s/h8s2100/h8s2113/index.jsp
  36  *
  37  * gmux is a microcontroller built into the MacBook Pro to support dual GPUs:
  38  * A {1}[Lattice XP2] on pre-retinas, a {2}[Renesas R4F2113] on retinas.
  39  *
  40  * (The MacPro6,1 2013 also has a gmux, however it is unclear why since it has
  41  * dual GPUs but no built-in display.)
  42  *
  43  * gmux is connected to the LPC bus of the southbridge. Its I/O ports are
  44  * accessed differently depending on the microcontroller: Driver functions
  45  * to access a pre-retina gmux are infixed `_pio_`, those for a retina gmux
  46  * are infixed `_index_`.
  47  */
  48
  49 struct apple_gmux_data {
  50         unsigned long iostart;
  51         unsigned long iolen;
  52         bool indexed;
  53         struct mutex index_lock;
  54
  55         struct pci_dev *pdev;
  56         struct backlight_device *bdev;
  57
  58         /* switcheroo data */
  59         acpi_handle dhandle;
  60         int gpe;
  61         enum vga_switcheroo_client_id switch_state_display;
  62         enum vga_switcheroo_client_id switch_state_ddc;
  63         enum vga_switcheroo_client_id switch_state_external;
  64         enum vga_switcheroo_state power_state;
  65         struct completion powerchange_done;
  66 };
  67
  68 static struct apple_gmux_data *apple_gmux_data;
  69
  70 /*
  71  * gmux port offsets. Many of these are not yet used, but may be in the
  72  * future, and it's useful to have them documented here anyhow.
  73  */
  74 #define GMUX_PORT_VERSION_MAJOR         0x04
  75 #define GMUX_PORT_VERSION_MINOR         0x05
  76 #define GMUX_PORT_VERSION_RELEASE       0x06
  77 #define GMUX_PORT_SWITCH_DISPLAY        0x10
  78 #define GMUX_PORT_SWITCH_GET_DISPLAY    0x11
  79 #define GMUX_PORT_INTERRUPT_ENABLE      0x14
  80 #define GMUX_PORT_INTERRUPT_STATUS      0x16
  81 #define GMUX_PORT_SWITCH_DDC            0x28
  82 #define GMUX_PORT_SWITCH_EXTERNAL       0x40
  83 #define GMUX_PORT_SWITCH_GET_EXTERNAL   0x41
  84 #define GMUX_PORT_DISCRETE_POWER        0x50
  85 #define GMUX_PORT_MAX_BRIGHTNESS        0x70
  86 #define GMUX_PORT_BRIGHTNESS            0x74
  87 #define GMUX_PORT_VALUE                 0xc2
  88 #define GMUX_PORT_READ                  0xd0
  89 #define GMUX_PORT_WRITE                 0xd4
  90
  91 #define GMUX_MIN_IO_LEN                 (GMUX_PORT_BRIGHTNESS + 4)
  92
  93 #define GMUX_INTERRUPT_ENABLE           0xff
  94 #define GMUX_INTERRUPT_DISABLE          0x00
  95
  96 #define GMUX_INTERRUPT_STATUS_ACTIVE    0
  97 #define GMUX_INTERRUPT_STATUS_DISPLAY   (1 << 0)
  98 #define GMUX_INTERRUPT_STATUS_POWER     (1 << 2)
  99 #define GMUX_INTERRUPT_STATUS_HOTPLUG   (1 << 3)
 100
 101 #define GMUX_BRIGHTNESS_MASK            0x00ffffff
 102 #define GMUX_MAX_BRIGHTNESS             GMUX_BRIGHTNESS_MASK
 103
 104 static u8 gmux_pio_read8(struct apple_gmux_data *gmux_data, int port)
 105 {
 106         return inb(gmux_data->iostart + port);
 107 }
 108
 109 static void gmux_pio_write8(struct apple_gmux_data *gmux_data, int port,
 110                                u8 val)
 111 {
 112         outb(val, gmux_data->iostart + port);
 113 }
 114
 115 static u32 gmux_pio_read32(struct apple_gmux_data *gmux_data, int port)
 116 {
 117         return inl(gmux_data->iostart + port);
 118 }
 119
 120 static void gmux_pio_write32(struct apple_gmux_data *gmux_data, int port,
 121                              u32 val)
 122 {
 123         int i;
 124         u8 tmpval;
 125
 126         for (i = 0; i < 4; i++) {
 127                 tmpval = (val >> (i * 8)) & 0xff;
 128                 outb(tmpval, gmux_data->iostart + port + i);
 129         }
 130 }
 131
 132 static int gmux_index_wait_ready(struct apple_gmux_data *gmux_data)
 133 {
 134         int i = 200;
 135         u8 gwr = inb(gmux_data->iostart + GMUX_PORT_WRITE);
 136
 137         while (i && (gwr & 0x01)) {
 138                 inb(gmux_data->iostart + GMUX_PORT_READ);
 139                 gwr = inb(gmux_data->iostart + GMUX_PORT_WRITE);
 140                 udelay(100);
 141                 i--;
 142         }
 143
 144         return !!i;
 145 }
 146
 147 static int gmux_index_wait_complete(struct apple_gmux_data *gmux_data)
 148 {
 149         int i = 200;
 150         u8 gwr = inb(gmux_data->iostart + GMUX_PORT_WRITE);
 151
 152         while (i && !(gwr & 0x01)) {
 153                 gwr = inb(gmux_data->iostart + GMUX_PORT_WRITE);
 154                 udelay(100);
 155                 i--;
 156         }
 157
 158         if (gwr & 0x01)
 159                 inb(gmux_data->iostart + GMUX_PORT_READ);
 160
 161         return !!i;
 162 }
 163
 164 static u8 gmux_index_read8(struct apple_gmux_data *gmux_data, int port)
 165 {
 166         u8 val;
 167
 168         mutex_lock(&gmux_data->index_lock);
 169         gmux_index_wait_ready(gmux_data);
 170         outb((port & 0xff), gmux_data->iostart + GMUX_PORT_READ);
 171         gmux_index_wait_complete(gmux_data);
 172         val = inb(gmux_data->iostart + GMUX_PORT_VALUE);
 173         mutex_unlock(&gmux_data->index_lock);
 174
 175         return val;
 176 }
 177
 178 static void gmux_index_write8(struct apple_gmux_data *gmux_data, int port,
 179                               u8 val)
 180 {
 181         mutex_lock(&gmux_data->index_lock);
 182         outb(val, gmux_data->iostart + GMUX_PORT_VALUE);
 183         gmux_index_wait_ready(gmux_data);
 184         outb(port & 0xff, gmux_data->iostart + GMUX_PORT_WRITE);
 185         gmux_index_wait_complete(gmux_data);
 186         mutex_unlock(&gmux_data->index_lock);
 187 }
 188
 189 static u32 gmux_index_read32(struct apple_gmux_data *gmux_data, int port)
 190 {
 191         u32 val;
 192
 193         mutex_lock(&gmux_data->index_lock);
 194         gmux_index_wait_ready(gmux_data);
 195         outb((port & 0xff), gmux_data->iostart + GMUX_PORT_READ);
 196         gmux_index_wait_complete(gmux_data);
 197         val = inl(gmux_data->iostart + GMUX_PORT_VALUE);
 198         mutex_unlock(&gmux_data->index_lock);
 199
 200         return val;
 201 }
 202
 203 static void gmux_index_write32(struct apple_gmux_data *gmux_data, int port,
 204                                u32 val)
 205 {
 206         int i;
 207         u8 tmpval;
 208
 209         mutex_lock(&gmux_data->index_lock);
 210
 211         for (i = 0; i < 4; i++) {
 212                 tmpval = (val >> (i * 8)) & 0xff;
 213                 outb(tmpval, gmux_data->iostart + GMUX_PORT_VALUE + i);
 214         }
 215
 216         gmux_index_wait_ready(gmux_data);
 217         outb(port & 0xff, gmux_data->iostart + GMUX_PORT_WRITE);
 218         gmux_index_wait_complete(gmux_data);
 219         mutex_unlock(&gmux_data->index_lock);
 220 }
 221
 222 static u8 gmux_read8(struct apple_gmux_data *gmux_data, int port)
 223 {
 224         if (gmux_data->indexed)
 225                 return gmux_index_read8(gmux_data, port);
 226         else
 227                 return gmux_pio_read8(gmux_data, port);
 228 }
 229
 230 static void gmux_write8(struct apple_gmux_data *gmux_data, int port, u8 val)
 231 {
 232         if (gmux_data->indexed)
 233                 gmux_index_write8(gmux_data, port, val);
 234         else
 235                 gmux_pio_write8(gmux_data, port, val);
 236 }
 237
 238 static u32 gmux_read32(struct apple_gmux_data *gmux_data, int port)
 239 {
 240         if (gmux_data->indexed)
 241                 return gmux_index_read32(gmux_data, port);
 242         else
 243                 return gmux_pio_read32(gmux_data, port);
 244 }
 245
 246 static void gmux_write32(struct apple_gmux_data *gmux_data, int port,
 247                              u32 val)
 248 {
 249         if (gmux_data->indexed)
 250                 gmux_index_write32(gmux_data, port, val);
 251         else
 252                 gmux_pio_write32(gmux_data, port, val);
 253 }
 254
 255 static bool gmux_is_indexed(struct apple_gmux_data *gmux_data)
 256 {
 257         u16 val;
 258
 259         outb(0xaa, gmux_data->iostart + 0xcc);
 260         outb(0x55, gmux_data->iostart + 0xcd);
 261         outb(0x00, gmux_data->iostart + 0xce);
 262
 263         val = inb(gmux_data->iostart + 0xcc) |
 264                 (inb(gmux_data->iostart + 0xcd) << 8);
 265
 266         if (val == 0x55aa)
 267                 return true;
 268
 269         return false;
 270 }
 271
 272 /**
 273  * DOC: Backlight control
 274  *
 275  * :3:  http://www.ti.com/lit/ds/symlink/lp8543.pdf
 276  * :4:  http://www.ti.com/lit/ds/symlink/lp8545.pdf
 277  *
 278  * On single GPU MacBooks, the PWM signal for the backlight is generated by
 279  * the GPU. On dual GPU MacBook Pros by contrast, either GPU may be suspended
 280  * to conserve energy. Hence the PWM signal needs to be generated by a separate
 281  * backlight driver which is controlled by gmux. The earliest generation
 282  * MBP5 2008/09 uses a {3}[TI LP8543] backlight driver. All newer models
 283  * use a {4}[TI LP8545].
 284  */
 285
 286 static int gmux_get_brightness(struct backlight_device *bd)
 287 {
 288         struct apple_gmux_data *gmux_data = bl_get_data(bd);
 289         return gmux_read32(gmux_data, GMUX_PORT_BRIGHTNESS) &
 290                GMUX_BRIGHTNESS_MASK;
 291 }
 292
 293 static int gmux_update_status(struct backlight_device *bd)
 294 {
 295         struct apple_gmux_data *gmux_data = bl_get_data(bd);
 296         u32 brightness = bd->props.brightness;
 297
 298         if (bd->props.state & BL_CORE_SUSPENDED)
 299                 return 0;
 300
 301         gmux_write32(gmux_data, GMUX_PORT_BRIGHTNESS, brightness);
 302
 303         return 0;
 304 }
 305
 306 static const struct backlight_ops gmux_bl_ops = {
 307         .options = BL_CORE_SUSPENDRESUME,
 308         .get_brightness = gmux_get_brightness,
 309         .update_status = gmux_update_status,
 310 };
 311
 312 /**
 313  * DOC: Graphics mux
 314  *
 315  * :5:  http://pimg-fpiw.uspto.gov/fdd/07/870/086/0.pdf
 316  * :6:  http://www.nxp.com/documents/data_sheet/CBTL06141.pdf
 317  * :7:  http://www.ti.com/lit/ds/symlink/hd3ss212.pdf
 318  * :8:  https://www.pericom.com/assets/Datasheets/PI3VDP12412.pdf
 319  * :9:  http://www.ti.com/lit/ds/symlink/sn74lv4066a.pdf
 320  * :10: http://pdf.datasheetarchive.com/indexerfiles/Datasheets-SW16/DSASW00308511.pdf
 321  * :11: http://www.ti.com/lit/ds/symlink/ts3ds10224.pdf
 322  *
 323  * On pre-retinas, the LVDS outputs of both GPUs feed into gmux which muxes
 324  * either of them to the panel. One of the tricks gmux has up its sleeve is
 325  * to lengthen the blanking interval of its output during a switch to
 326  * synchronize it with the GPU switched to. This allows for a flicker-free
 327  * switch that is imperceptible by the user ({5}[US 8,687,007 B2]).
 328  *
 329  * On retinas, muxing is no longer done by gmux itself, but by a separate
 330  * chip which is controlled by gmux. The chip is triple sourced, it is
 331  * either an {6}[NXP CBTL06142], {7}[TI HD3SS212] or {8}[Pericom PI3VDP12412].
 332  * The panel is driven with eDP instead of LVDS since the pixel clock
 333  * required for retina resolution exceeds LVDS' limits.
 334  *
 335  * Pre-retinas are able to switch the panel's DDC pins separately.
 336  * This is handled by a {9}[TI SN74LV4066A] which is controlled by gmux.
 337  * The inactive GPU can thus probe the panel's EDID without switching over
 338  * the entire panel. Retinas lack this functionality as the chips used for
 339  * eDP muxing are incapable of switching the AUX channel separately (see
 340  * the linked data sheets, Pericom would be capable but this is unused).
 341  * However the retina panel has the NO_AUX_HANDSHAKE_LINK_TRAINING bit set
 342  * in its DPCD, allowing the inactive GPU to skip the AUX handshake and
 343  * set up the output with link parameters pre-calibrated by the active GPU.
 344  *
 345  * The external DP port is only fully switchable on the first two unibody
 346  * MacBook Pro generations, MBP5 2008/09 and MBP6 2010. This is done by an
 347  * {6}[NXP CBTL06141] which is controlled by gmux. It's the predecessor of the
 348  * eDP mux on retinas, the difference being support for 2.7 versus 5.4 Gbit/s.
 349  *
 350  * The following MacBook Pro generations replaced the external DP port with a
 351  * combined DP/Thunderbolt port and lost the ability to switch it between GPUs,
 352  * connecting it either to the discrete GPU or the Thunderbolt controller.
 353  * Oddly enough, while the full port is no longer switchable, AUX and HPD
 354  * are still switchable by way of an {10}[NXP CBTL03062] (on pre-retinas
 355  * MBP8 2011 and MBP9 2012) or two {11}[TI TS3DS10224] (on retinas) under the
 356  * control of gmux. Since the integrated GPU is missing the main link,
 357  * external displays appear to it as phantoms which fail to link-train.
 358  *
 359  * gmux receives the HPD signal of all display connectors and sends an
 360  * interrupt on hotplug. On generations which cannot switch external ports,
 361  * the discrete GPU can then be woken to drive the newly connected display.
 362  * The ability to switch AUX on these generations could be used to improve
 363  * reliability of hotplug detection by having the integrated GPU poll the
 364  * ports while the discrete GPU is asleep, but currently we do not make use
 365  * of this feature.
 366  *
 367  * gmux' initial switch state on bootup is user configurable via the EFI
 368  * variable `gpu-power-prefs-fa4ce28d-b62f-4c99-9cc3-6815686e30f9` (5th byte,
 369  * 1 = IGD, 0 = DIS). Based on this setting, the EFI firmware tells gmux to
 370  * switch the panel and the external DP connector and allocates a framebuffer
 371  * for the selected GPU.
 372  */
 373
 374 static void gmux_read_switch_state(struct apple_gmux_data *gmux_data)
 375 {
 376         if (gmux_read8(gmux_data, GMUX_PORT_SWITCH_DDC) == 1)
 377                 gmux_data->switch_state_ddc = VGA_SWITCHEROO_IGD;
 378         else
 379                 gmux_data->switch_state_ddc = VGA_SWITCHEROO_DIS;
 380
 381         if (gmux_read8(gmux_data, GMUX_PORT_SWITCH_DISPLAY) == 2)
 382                 gmux_data->switch_state_display = VGA_SWITCHEROO_IGD;
 383         else
 384                 gmux_data->switch_state_display = VGA_SWITCHEROO_DIS;
 385
 386         if (gmux_read8(gmux_data, GMUX_PORT_SWITCH_EXTERNAL) == 2)
 387                 gmux_data->switch_state_external = VGA_SWITCHEROO_IGD;
 388         else
 389                 gmux_data->switch_state_external = VGA_SWITCHEROO_DIS;
 390 }
 391
 392 static void gmux_write_switch_state(struct apple_gmux_data *gmux_data)
 393 {
 394         if (gmux_data->switch_state_ddc == VGA_SWITCHEROO_IGD)
 395                 gmux_write8(gmux_data, GMUX_PORT_SWITCH_DDC, 1);
 396         else
 397                 gmux_write8(gmux_data, GMUX_PORT_SWITCH_DDC, 2);
 398
 399         if (gmux_data->switch_state_display == VGA_SWITCHEROO_IGD)
 400                 gmux_write8(gmux_data, GMUX_PORT_SWITCH_DISPLAY, 2);
 401         else
 402                 gmux_write8(gmux_data, GMUX_PORT_SWITCH_DISPLAY, 3);
 403
 404         if (gmux_data->switch_state_external == VGA_SWITCHEROO_IGD)
 405                 gmux_write8(gmux_data, GMUX_PORT_SWITCH_EXTERNAL, 2);
 406         else
 407                 gmux_write8(gmux_data, GMUX_PORT_SWITCH_EXTERNAL, 3);
 408 }
 409
 410 static int gmux_switchto(enum vga_switcheroo_client_id id)
 411 {
 412         apple_gmux_data->switch_state_ddc = id;
 413         apple_gmux_data->switch_state_display = id;
 414         apple_gmux_data->switch_state_external = id;
 415
 416         gmux_write_switch_state(apple_gmux_data);
 417
 418         return 0;
 419 }
 420
 421 static int gmux_switch_ddc(enum vga_switcheroo_client_id id)
 422 {
 423         enum vga_switcheroo_client_id old_ddc_owner =
 424                 apple_gmux_data->switch_state_ddc;
 425
 426         if (id == old_ddc_owner)
 427                 return id;
 428
 429         pr_debug("Switching DDC from %d to %d\n", old_ddc_owner, id);
 430         apple_gmux_data->switch_state_ddc = id;
 431
 432         if (id == VGA_SWITCHEROO_IGD)
 433                 gmux_write8(apple_gmux_data, GMUX_PORT_SWITCH_DDC, 1);
 434         else
 435                 gmux_write8(apple_gmux_data, GMUX_PORT_SWITCH_DDC, 2);
 436
 437         return old_ddc_owner;
 438 }
 439
 440 /**
 441  * DOC: Power control
 442  *
 443  * gmux is able to cut power to the discrete GPU. It automatically takes care
 444  * of the correct sequence to tear down and bring up the power rails for
 445  * core voltage, VRAM and PCIe.
 446  */
 447
 448 static int gmux_set_discrete_state(struct apple_gmux_data *gmux_data,
 449                                    enum vga_switcheroo_state state)
 450 {
 451         reinit_completion(&gmux_data->powerchange_done);
 452
 453         if (state == VGA_SWITCHEROO_ON) {
 454                 gmux_write8(gmux_data, GMUX_PORT_DISCRETE_POWER, 1);
 455                 gmux_write8(gmux_data, GMUX_PORT_DISCRETE_POWER, 3);
 456                 pr_debug("Discrete card powered up\n");
 457         } else {
 458                 gmux_write8(gmux_data, GMUX_PORT_DISCRETE_POWER, 1);
 459                 gmux_write8(gmux_data, GMUX_PORT_DISCRETE_POWER, 0);
 460                 pr_debug("Discrete card powered down\n");
 461         }
 462
 463         gmux_data->power_state = state;
 464
 465         if (gmux_data->gpe >= 0 &&
 466             !wait_for_completion_interruptible_timeout(&gmux_data->powerchange_done,
 467                                                        msecs_to_jiffies(200)))
 468                 pr_warn("Timeout waiting for gmux switch to complete\n");
 469
 470         return 0;
 471 }
 472
 473 static int gmux_set_power_state(enum vga_switcheroo_client_id id,
 474                                 enum vga_switcheroo_state state)
 475 {
 476         if (id == VGA_SWITCHEROO_IGD)
 477                 return 0;
 478
 479         return gmux_set_discrete_state(apple_gmux_data, state);
 480 }
 481
 482 static int gmux_get_client_id(struct pci_dev *pdev)
 483 {
 484         /*
 485          * Early Macbook Pros with switchable graphics use nvidia
 486          * integrated graphics. Hardcode that the 9400M is integrated.
 487          */
 488         if (pdev->vendor == PCI_VENDOR_ID_INTEL)
 489                 return VGA_SWITCHEROO_IGD;
 490         else if (pdev->vendor == PCI_VENDOR_ID_NVIDIA &&
 491                  pdev->device == 0x0863)
 492                 return VGA_SWITCHEROO_IGD;
 493         else
 494                 return VGA_SWITCHEROO_DIS;
 495 }
 496
 497 static const struct vga_switcheroo_handler gmux_handler_indexed = {
 498         .switchto = gmux_switchto,
 499         .power_state = gmux_set_power_state,
 500         .get_client_id = gmux_get_client_id,
 501 };
 502
 503 static const struct vga_switcheroo_handler gmux_handler_classic = {
 504         .switchto = gmux_switchto,
 505         .switch_ddc = gmux_switch_ddc,
 506         .power_state = gmux_set_power_state,
 507         .get_client_id = gmux_get_client_id,
 508 };
 509
 510 /**
 511  * DOC: Interrupt
 512  *
 513  * gmux is also connected to a GPIO pin of the southbridge and thereby is able
 514  * to trigger an ACPI GPE. On the MBP5 2008/09 it's GPIO pin 22 of the Nvidia
 515  * MCP79, on all following generations it's GPIO pin 6 of the Intel PCH.
 516  * The GPE merely signals that an interrupt occurred, the actual type of event
 517  * is identified by reading a gmux register.
 518  */
 519
 520 static inline void gmux_disable_interrupts(struct apple_gmux_data *gmux_data)
 521 {
 522         gmux_write8(gmux_data, GMUX_PORT_INTERRUPT_ENABLE,
 523                     GMUX_INTERRUPT_DISABLE);
 524 }
 525
 526 static inline void gmux_enable_interrupts(struct apple_gmux_data *gmux_data)
 527 {
 528         gmux_write8(gmux_data, GMUX_PORT_INTERRUPT_ENABLE,
 529                     GMUX_INTERRUPT_ENABLE);
 530 }
 531
 532 static inline u8 gmux_interrupt_get_status(struct apple_gmux_data *gmux_data)
 533 {
 534         return gmux_read8(gmux_data, GMUX_PORT_INTERRUPT_STATUS);
 535 }
 536
 537 static void gmux_clear_interrupts(struct apple_gmux_data *gmux_data)
 538 {
 539         u8 status;
 540
 541         /* to clear interrupts write back current status */
 542         status = gmux_interrupt_get_status(gmux_data);
 543         gmux_write8(gmux_data, GMUX_PORT_INTERRUPT_STATUS, status);
 544 }
 545
 546 static void gmux_notify_handler(acpi_handle device, u32 value, void *context)
 547 {
 548         u8 status;
 549         struct pnp_dev *pnp = (struct pnp_dev *)context;
 550         struct apple_gmux_data *gmux_data = pnp_get_drvdata(pnp);
 551
 552         status = gmux_interrupt_get_status(gmux_data);
 553         gmux_disable_interrupts(gmux_data);
 554         pr_debug("Notify handler called: status %d\n", status);
 555
 556         gmux_clear_interrupts(gmux_data);
 557         gmux_enable_interrupts(gmux_data);
 558
 559         if (status & GMUX_INTERRUPT_STATUS_POWER)
 560                 complete(&gmux_data->powerchange_done);
 561 }
 562
 563 static int gmux_suspend(struct device *dev)
 564 {
 565         struct pnp_dev *pnp = to_pnp_dev(dev);
 566         struct apple_gmux_data *gmux_data = pnp_get_drvdata(pnp);
 567
 568         gmux_disable_interrupts(gmux_data);
 569         return 0;
 570 }
 571
 572 static int gmux_resume(struct device *dev)
 573 {
 574         struct pnp_dev *pnp = to_pnp_dev(dev);
 575         struct apple_gmux_data *gmux_data = pnp_get_drvdata(pnp);
 576
 577         gmux_enable_interrupts(gmux_data);
 578         gmux_write_switch_state(gmux_data);
 579         if (gmux_data->power_state == VGA_SWITCHEROO_OFF)
 580                 gmux_set_discrete_state(gmux_data, gmux_data->power_state);
 581         return 0;
 582 }
 583
 584 static struct pci_dev *gmux_get_io_pdev(void)
 585 {
 586         struct pci_dev *pdev = NULL;
 587
 588         while ((pdev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, pdev))) {
 589                 u16 cmd;
 590
 591                 pci_read_config_word(pdev, PCI_COMMAND, &cmd);
 592                 if (!(cmd & PCI_COMMAND_IO))
 593                         continue;
 594
 595                 return pdev;
 596         }
 597
 598         return NULL;
 599 }
 600
 601 static int gmux_probe(struct pnp_dev *pnp, const struct pnp_device_id *id)
 602 {
 603         struct apple_gmux_data *gmux_data;
 604         struct resource *res;
 605         struct backlight_properties props;
 606         struct backlight_device *bdev;
 607         u8 ver_major, ver_minor, ver_release;
 608         int ret = -ENXIO;
 609         acpi_status status;
 610         unsigned long long gpe;
 611         struct pci_dev *pdev = NULL;
 612
 613         if (apple_gmux_data)
 614                 return -EBUSY;
 615
 616         gmux_data = kzalloc(sizeof(*gmux_data), GFP_KERNEL);
 617         if (!gmux_data)
 618                 return -ENOMEM;
 619         pnp_set_drvdata(pnp, gmux_data);
 620
 621         res = pnp_get_resource(pnp, IORESOURCE_IO, 0);
 622         if (!res) {
 623                 pr_err("Failed to find gmux I/O resource\n");
 624                 goto err_free;
 625         }
 626
 627         gmux_data->iostart = res->start;
 628         gmux_data->iolen = res->end - res->start;
 629
 630         if (gmux_data->iolen < GMUX_MIN_IO_LEN) {
 631                 pr_err("gmux I/O region too small (%lu < %u)\n",
 632                        gmux_data->iolen, GMUX_MIN_IO_LEN);
 633                 goto err_free;
 634         }
 635
 636         if (!request_region(gmux_data->iostart, gmux_data->iolen,
 637                             "Apple gmux")) {
 638                 pr_err("gmux I/O already in use\n");
 639                 goto err_free;
 640         }
 641
 642         /*
 643          * Invalid version information may indicate either that the gmux
 644          * device isn't present or that it's a new one that uses indexed
 645          * io
 646          */
 647
 648         ver_major = gmux_read8(gmux_data, GMUX_PORT_VERSION_MAJOR);
 649         ver_minor = gmux_read8(gmux_data, GMUX_PORT_VERSION_MINOR);
 650         ver_release = gmux_read8(gmux_data, GMUX_PORT_VERSION_RELEASE);
 651         if (ver_major == 0xff && ver_minor == 0xff && ver_release == 0xff) {
 652                 if (gmux_is_indexed(gmux_data)) {
 653                         u32 version;
 654                         mutex_init(&gmux_data->index_lock);
 655                         gmux_data->indexed = true;
 656                         version = gmux_read32(gmux_data,
 657                                 GMUX_PORT_VERSION_MAJOR);
 658                         ver_major = (version >> 24) & 0xff;
 659                         ver_minor = (version >> 16) & 0xff;
 660                         ver_release = (version >> 8) & 0xff;
 661                 } else {
 662                         pr_info("gmux device not present or IO disabled\n");
 663                         ret = -ENODEV;
 664                         goto err_release;
 665                 }
 666         }
 667         pr_info("Found gmux version %d.%d.%d [%s]\n", ver_major, ver_minor,
 668                 ver_release, (gmux_data->indexed ? "indexed" : "classic"));
 669
 670         /*
 671          * Apple systems with gmux are EFI based and normally don't use
 672          * VGA. In addition changing IO+MEM ownership between IGP and dGPU
 673          * disables IO/MEM used for backlight control on some systems.
 674          * Lock IO+MEM to GPU with active IO to prevent switch.
 675          */
 676         pdev = gmux_get_io_pdev();
 677         if (pdev && vga_tryget(pdev,
 678                                VGA_RSRC_NORMAL_IO | VGA_RSRC_NORMAL_MEM)) {
 679                 pr_err("IO+MEM vgaarb-locking for PCI:%s failed\n",
 680                         pci_name(pdev));
 681                 ret = -EBUSY;
 682                 goto err_release;
 683         } else if (pdev)
 684                 pr_info("locked IO for PCI:%s\n", pci_name(pdev));
 685         gmux_data->pdev = pdev;
 686
 687         memset(&props, 0, sizeof(props));
 688         props.type = BACKLIGHT_PLATFORM;
 689         props.max_brightness = gmux_read32(gmux_data, GMUX_PORT_MAX_BRIGHTNESS);
 690
 691         /*
 692          * Currently it's assumed that the maximum brightness is less than
 693          * 2^24 for compatibility with old gmux versions. Cap the max
 694          * brightness at this value, but print a warning if the hardware
 695          * reports something higher so that it can be fixed.
 696          */
 697         if (WARN_ON(props.max_brightness > GMUX_MAX_BRIGHTNESS))
 698                 props.max_brightness = GMUX_MAX_BRIGHTNESS;
 699
 700         bdev = backlight_device_register("gmux_backlight", &pnp->dev,
 701                                          gmux_data, &gmux_bl_ops, &props);
 702         if (IS_ERR(bdev)) {
 703                 ret = PTR_ERR(bdev);
 704                 goto err_release;
 705         }
 706
 707         gmux_data->bdev = bdev;
 708         bdev->props.brightness = gmux_get_brightness(bdev);
 709         backlight_update_status(bdev);
 710
 711         /*
 712          * The backlight situation on Macs is complicated. If the gmux is
 713          * present it's the best choice, because it always works for
 714          * backlight control and supports more levels than other options.
 715          * Disable the other backlight choices.
 716          */
 717         acpi_video_set_dmi_backlight_type(acpi_backlight_vendor);
 718         apple_bl_unregister();
 719
 720         gmux_data->power_state = VGA_SWITCHEROO_ON;
 721
 722         gmux_data->dhandle = ACPI_HANDLE(&pnp->dev);
 723         if (!gmux_data->dhandle) {
 724                 pr_err("Cannot find acpi handle for pnp device %s\n",
 725                        dev_name(&pnp->dev));
 726                 ret = -ENODEV;
 727                 goto err_notify;
 728         }
 729
 730         status = acpi_evaluate_integer(gmux_data->dhandle, "GMGP", NULL, &gpe);
 731         if (ACPI_SUCCESS(status)) {
 732                 gmux_data->gpe = (int)gpe;
 733
 734                 status = acpi_install_notify_handler(gmux_data->dhandle,
 735                                                      ACPI_DEVICE_NOTIFY,
 736                                                      &gmux_notify_handler, pnp);
 737                 if (ACPI_FAILURE(status)) {
 738                         pr_err("Install notify handler failed: %s\n",
 739                                acpi_format_exception(status));
 740                         ret = -ENODEV;
 741                         goto err_notify;
 742                 }
 743
 744                 status = acpi_enable_gpe(NULL, gmux_data->gpe);
 745                 if (ACPI_FAILURE(status)) {
 746                         pr_err("Cannot enable gpe: %s\n",
 747                                acpi_format_exception(status));
 748                         goto err_enable_gpe;
 749                 }
 750         } else {
 751                 pr_warn("No GPE found for gmux\n");
 752                 gmux_data->gpe = -1;
 753         }
 754
 755         apple_gmux_data = gmux_data;
 756         init_completion(&gmux_data->powerchange_done);
 757         gmux_enable_interrupts(gmux_data);
 758         gmux_read_switch_state(gmux_data);
 759
 760         /*
 761          * Retina MacBook Pros cannot switch the panel's AUX separately
 762          * and need eDP pre-calibration. They are distinguishable from
 763          * pre-retinas by having an "indexed" gmux.
 764          *
 765          * Pre-retina MacBook Pros can switch the panel's DDC separately.
 766          */
 767         if (gmux_data->indexed)
 768                 ret = vga_switcheroo_register_handler(&gmux_handler_indexed,
 769                                               VGA_SWITCHEROO_NEEDS_EDP_CONFIG);
 770         else
 771                 ret = vga_switcheroo_register_handler(&gmux_handler_classic,
 772                                               VGA_SWITCHEROO_CAN_SWITCH_DDC);
 773         if (ret) {
 774                 pr_err("Failed to register vga_switcheroo handler\n");
 775                 goto err_register_handler;
 776         }
 777
 778         return 0;
 779
 780 err_register_handler:
 781         gmux_disable_interrupts(gmux_data);
 782         apple_gmux_data = NULL;
 783         if (gmux_data->gpe >= 0)
 784                 acpi_disable_gpe(NULL, gmux_data->gpe);
 785 err_enable_gpe:
 786         if (gmux_data->gpe >= 0)
 787                 acpi_remove_notify_handler(gmux_data->dhandle,
 788                                            ACPI_DEVICE_NOTIFY,
 789                                            &gmux_notify_handler);
 790 err_notify:
 791         backlight_device_unregister(bdev);
 792 err_release:
 793         if (gmux_data->pdev)
 794                 vga_put(gmux_data->pdev,
 795                         VGA_RSRC_NORMAL_IO | VGA_RSRC_NORMAL_MEM);
 796         pci_dev_put(pdev);
 797         release_region(gmux_data->iostart, gmux_data->iolen);
 798 err_free:
 799         kfree(gmux_data);
 800         return ret;
 801 }
 802
 803 static void gmux_remove(struct pnp_dev *pnp)
 804 {
 805         struct apple_gmux_data *gmux_data = pnp_get_drvdata(pnp);
 806
 807         vga_switcheroo_unregister_handler();
 808         gmux_disable_interrupts(gmux_data);
 809         if (gmux_data->gpe >= 0) {
 810                 acpi_disable_gpe(NULL, gmux_data->gpe);
 811                 acpi_remove_notify_handler(gmux_data->dhandle,
 812                                            ACPI_DEVICE_NOTIFY,
 813                                            &gmux_notify_handler);
 814         }
 815
 816         if (gmux_data->pdev) {
 817                 vga_put(gmux_data->pdev,
 818                         VGA_RSRC_NORMAL_IO | VGA_RSRC_NORMAL_MEM);
 819                 pci_dev_put(gmux_data->pdev);
 820         }
 821         backlight_device_unregister(gmux_data->bdev);
 822
 823         release_region(gmux_data->iostart, gmux_data->iolen);
 824         apple_gmux_data = NULL;
 825         kfree(gmux_data);
 826
 827         acpi_video_register();
 828         apple_bl_register();
 829 }
 830
 831 static const struct pnp_device_id gmux_device_ids[] = {
 832         {GMUX_ACPI_HID, 0},
 833         {"", 0}
 834 };
 835
 836 static const struct dev_pm_ops gmux_dev_pm_ops = {
 837         .suspend = gmux_suspend,
 838         .resume = gmux_resume,
 839 };
 840
 841 static struct pnp_driver gmux_pnp_driver = {
 842         .name           = "apple-gmux",
 843         .probe          = gmux_probe,
 844         .remove         = gmux_remove,
 845         .id_table       = gmux_device_ids,
 846         .driver         = {
 847                         .pm = &gmux_dev_pm_ops,
 848         },
 849 };
 850
 851 module_pnp_driver(gmux_pnp_driver);
 852 MODULE_AUTHOR("Seth Forshee <seth.forshee@canonical.com>");
 853 MODULE_DESCRIPTION("Apple Gmux Driver");
 854 MODULE_LICENSE("GPL");
 855 MODULE_DEVICE_TABLE(pnp, gmux_device_ids);