1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Gmux driver for Apple laptops 4 * 5 * Copyright (C) Canonical Ltd. <seth.forshee@canonical.com> 6 * Copyright (C) 2010-2012 Andreas Heider <andreas@meetr.de> 7 * Copyright (C) 2015 Lukas Wunner <lukas@wunner.de> 8 * Copyright (C) 2023 Orlando Chamberlain <orlandoch.dev@gmail.com> 9 */ 10 11 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 12 13 #include <linux/module.h> 14 #include <linux/kernel.h> 15 #include <linux/init.h> 16 #include <linux/backlight.h> 17 #include <linux/acpi.h> 18 #include <linux/pnp.h> 19 #include <linux/apple-gmux.h> 20 #include <linux/slab.h> 21 #include <linux/delay.h> 22 #include <linux/pci.h> 23 #include <linux/vga_switcheroo.h> 24 #include <linux/debugfs.h> 25 #include <acpi/video.h> 26 #include <asm/io.h> 27 28 /** 29 * DOC: Overview 30 * 31 * gmux is a microcontroller built into the MacBook Pro to support dual GPUs: 32 * A `Lattice XP2`_ on pre-retinas, a `Renesas R4F2113`_ on pre-T2 retinas. 33 * 34 * On T2 Macbooks, the gmux is part of the T2 Coprocessor's SMC. The SMC has 35 * an I2C connection to a `NXP PCAL6524` GPIO expander, which enables/disables 36 * the voltage regulators of the discrete GPU, drives the display panel power, 37 * and has a GPIO to switch the eDP mux. The Intel CPU can interact with 38 * gmux through MMIO, similar to how the main SMC interface is controlled. 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 pre-T2 46 * retina gmux are infixed ``_index_``, and those on T2 Macs are infixed 47 * with ``_mmio_``. 48 * 49 * .. _Lattice XP2: 50 * http://www.latticesemi.com/en/Products/FPGAandCPLD/LatticeXP2.aspx 51 * .. _Renesas R4F2113: 52 * http://www.renesas.com/products/mpumcu/h8s/h8s2100/h8s2113/index.jsp 53 * .. _NXP PCAL6524: 54 * https://www.nxp.com/docs/en/data-sheet/PCAL6524.pdf 55 */ 56 57 struct apple_gmux_config; 58 59 struct apple_gmux_data { 60 u8 __iomem *iomem_base; 61 unsigned long iostart; 62 unsigned long iolen; 63 const struct apple_gmux_config *config; 64 struct mutex index_lock; 65 66 struct backlight_device *bdev; 67 68 /* switcheroo data */ 69 acpi_handle dhandle; 70 int gpe; 71 bool external_switchable; 72 enum vga_switcheroo_client_id switch_state_display; 73 enum vga_switcheroo_client_id switch_state_ddc; 74 enum vga_switcheroo_client_id switch_state_external; 75 enum vga_switcheroo_state power_state; 76 struct completion powerchange_done; 77 78 /* debugfs data */ 79 u8 selected_port; 80 struct dentry *debug_dentry; 81 }; 82 83 static struct apple_gmux_data *apple_gmux_data; 84 85 struct apple_gmux_config { 86 u8 (*read8)(struct apple_gmux_data *gmux_data, int port); 87 void (*write8)(struct apple_gmux_data *gmux_data, int port, u8 val); 88 u32 (*read32)(struct apple_gmux_data *gmux_data, int port); 89 void (*write32)(struct apple_gmux_data *gmux_data, int port, u32 val); 90 const struct vga_switcheroo_handler *gmux_handler; 91 enum vga_switcheroo_handler_flags_t handler_flags; 92 unsigned long resource_type; 93 bool read_version_as_u32; 94 char *name; 95 }; 96 97 #define GMUX_INTERRUPT_ENABLE 0xff 98 #define GMUX_INTERRUPT_DISABLE 0x00 99 100 #define GMUX_INTERRUPT_STATUS_ACTIVE 0 101 #define GMUX_INTERRUPT_STATUS_DISPLAY (1 << 0) 102 #define GMUX_INTERRUPT_STATUS_POWER (1 << 2) 103 #define GMUX_INTERRUPT_STATUS_HOTPLUG (1 << 3) 104 105 #define GMUX_BRIGHTNESS_MASK 0x00ffffff 106 #define GMUX_MAX_BRIGHTNESS GMUX_BRIGHTNESS_MASK 107 108 static u8 gmux_pio_read8(struct apple_gmux_data *gmux_data, int port) 109 { 110 return inb(gmux_data->iostart + port); 111 } 112 113 static void gmux_pio_write8(struct apple_gmux_data *gmux_data, int port, 114 u8 val) 115 { 116 outb(val, gmux_data->iostart + port); 117 } 118 119 static u32 gmux_pio_read32(struct apple_gmux_data *gmux_data, int port) 120 { 121 return inl(gmux_data->iostart + port); 122 } 123 124 static void gmux_pio_write32(struct apple_gmux_data *gmux_data, int port, 125 u32 val) 126 { 127 int i; 128 u8 tmpval; 129 130 for (i = 0; i < 4; i++) { 131 tmpval = (val >> (i * 8)) & 0xff; 132 outb(tmpval, gmux_data->iostart + port + i); 133 } 134 } 135 136 static int gmux_index_wait_ready(struct apple_gmux_data *gmux_data) 137 { 138 int i = 200; 139 u8 gwr = inb(gmux_data->iostart + GMUX_PORT_WRITE); 140 141 while (i && (gwr & 0x01)) { 142 inb(gmux_data->iostart + GMUX_PORT_READ); 143 gwr = inb(gmux_data->iostart + GMUX_PORT_WRITE); 144 udelay(100); 145 i--; 146 } 147 148 return !!i; 149 } 150 151 static int gmux_index_wait_complete(struct apple_gmux_data *gmux_data) 152 { 153 int i = 200; 154 u8 gwr = inb(gmux_data->iostart + GMUX_PORT_WRITE); 155 156 while (i && !(gwr & 0x01)) { 157 gwr = inb(gmux_data->iostart + GMUX_PORT_WRITE); 158 udelay(100); 159 i--; 160 } 161 162 if (gwr & 0x01) 163 inb(gmux_data->iostart + GMUX_PORT_READ); 164 165 return !!i; 166 } 167 168 static u8 gmux_index_read8(struct apple_gmux_data *gmux_data, int port) 169 { 170 u8 val; 171 172 mutex_lock(&gmux_data->index_lock); 173 gmux_index_wait_ready(gmux_data); 174 outb((port & 0xff), gmux_data->iostart + GMUX_PORT_READ); 175 gmux_index_wait_complete(gmux_data); 176 val = inb(gmux_data->iostart + GMUX_PORT_VALUE); 177 mutex_unlock(&gmux_data->index_lock); 178 179 return val; 180 } 181 182 static void gmux_index_write8(struct apple_gmux_data *gmux_data, int port, 183 u8 val) 184 { 185 mutex_lock(&gmux_data->index_lock); 186 outb(val, gmux_data->iostart + GMUX_PORT_VALUE); 187 gmux_index_wait_ready(gmux_data); 188 outb(port & 0xff, gmux_data->iostart + GMUX_PORT_WRITE); 189 gmux_index_wait_complete(gmux_data); 190 mutex_unlock(&gmux_data->index_lock); 191 } 192 193 static u32 gmux_index_read32(struct apple_gmux_data *gmux_data, int port) 194 { 195 u32 val; 196 197 mutex_lock(&gmux_data->index_lock); 198 gmux_index_wait_ready(gmux_data); 199 outb((port & 0xff), gmux_data->iostart + GMUX_PORT_READ); 200 gmux_index_wait_complete(gmux_data); 201 val = inl(gmux_data->iostart + GMUX_PORT_VALUE); 202 mutex_unlock(&gmux_data->index_lock); 203 204 return val; 205 } 206 207 static void gmux_index_write32(struct apple_gmux_data *gmux_data, int port, 208 u32 val) 209 { 210 int i; 211 u8 tmpval; 212 213 mutex_lock(&gmux_data->index_lock); 214 215 for (i = 0; i < 4; i++) { 216 tmpval = (val >> (i * 8)) & 0xff; 217 outb(tmpval, gmux_data->iostart + GMUX_PORT_VALUE + i); 218 } 219 220 gmux_index_wait_ready(gmux_data); 221 outb(port & 0xff, gmux_data->iostart + GMUX_PORT_WRITE); 222 gmux_index_wait_complete(gmux_data); 223 mutex_unlock(&gmux_data->index_lock); 224 } 225 226 static int gmux_mmio_wait(struct apple_gmux_data *gmux_data) 227 { 228 int i = 200; 229 u8 gwr = ioread8(gmux_data->iomem_base + GMUX_MMIO_COMMAND_SEND); 230 231 while (i && gwr) { 232 gwr = ioread8(gmux_data->iomem_base + GMUX_MMIO_COMMAND_SEND); 233 udelay(100); 234 i--; 235 } 236 237 return !!i; 238 } 239 240 static u8 gmux_mmio_read8(struct apple_gmux_data *gmux_data, int port) 241 { 242 u8 val; 243 244 mutex_lock(&gmux_data->index_lock); 245 gmux_mmio_wait(gmux_data); 246 iowrite8((port & 0xff), gmux_data->iomem_base + GMUX_MMIO_PORT_SELECT); 247 iowrite8(GMUX_MMIO_READ | sizeof(val), 248 gmux_data->iomem_base + GMUX_MMIO_COMMAND_SEND); 249 gmux_mmio_wait(gmux_data); 250 val = ioread8(gmux_data->iomem_base); 251 mutex_unlock(&gmux_data->index_lock); 252 253 return val; 254 } 255 256 static void gmux_mmio_write8(struct apple_gmux_data *gmux_data, int port, 257 u8 val) 258 { 259 mutex_lock(&gmux_data->index_lock); 260 gmux_mmio_wait(gmux_data); 261 iowrite8(val, gmux_data->iomem_base); 262 263 iowrite8(port & 0xff, gmux_data->iomem_base + GMUX_MMIO_PORT_SELECT); 264 iowrite8(GMUX_MMIO_WRITE | sizeof(val), 265 gmux_data->iomem_base + GMUX_MMIO_COMMAND_SEND); 266 267 gmux_mmio_wait(gmux_data); 268 mutex_unlock(&gmux_data->index_lock); 269 } 270 271 static u32 gmux_mmio_read32(struct apple_gmux_data *gmux_data, int port) 272 { 273 u32 val; 274 275 mutex_lock(&gmux_data->index_lock); 276 gmux_mmio_wait(gmux_data); 277 iowrite8((port & 0xff), gmux_data->iomem_base + GMUX_MMIO_PORT_SELECT); 278 iowrite8(GMUX_MMIO_READ | sizeof(val), 279 gmux_data->iomem_base + GMUX_MMIO_COMMAND_SEND); 280 gmux_mmio_wait(gmux_data); 281 val = ioread32be(gmux_data->iomem_base); 282 mutex_unlock(&gmux_data->index_lock); 283 284 return val; 285 } 286 287 static void gmux_mmio_write32(struct apple_gmux_data *gmux_data, int port, 288 u32 val) 289 { 290 mutex_lock(&gmux_data->index_lock); 291 iowrite32be(val, gmux_data->iomem_base); 292 iowrite8(port & 0xff, gmux_data->iomem_base + GMUX_MMIO_PORT_SELECT); 293 iowrite8(GMUX_MMIO_WRITE | sizeof(val), 294 gmux_data->iomem_base + GMUX_MMIO_COMMAND_SEND); 295 gmux_mmio_wait(gmux_data); 296 mutex_unlock(&gmux_data->index_lock); 297 } 298 299 static u8 gmux_read8(struct apple_gmux_data *gmux_data, int port) 300 { 301 return gmux_data->config->read8(gmux_data, port); 302 } 303 304 static void gmux_write8(struct apple_gmux_data *gmux_data, int port, u8 val) 305 { 306 return gmux_data->config->write8(gmux_data, port, val); 307 } 308 309 static u32 gmux_read32(struct apple_gmux_data *gmux_data, int port) 310 { 311 return gmux_data->config->read32(gmux_data, port); 312 } 313 314 static void gmux_write32(struct apple_gmux_data *gmux_data, int port, 315 u32 val) 316 { 317 return gmux_data->config->write32(gmux_data, port, val); 318 } 319 320 /** 321 * DOC: Backlight control 322 * 323 * On single GPU MacBooks, the PWM signal for the backlight is generated by 324 * the GPU. On dual GPU MacBook Pros by contrast, either GPU may be suspended 325 * to conserve energy. Hence the PWM signal needs to be generated by a separate 326 * backlight driver which is controlled by gmux. The earliest generation 327 * MBP5 2008/09 uses a `TI LP8543`_ backlight driver. Newer models 328 * use a `TI LP8545`_ or a TI LP8548. 329 * 330 * .. _TI LP8543: https://www.ti.com/lit/ds/symlink/lp8543.pdf 331 * .. _TI LP8545: https://www.ti.com/lit/ds/symlink/lp8545.pdf 332 */ 333 334 static int gmux_get_brightness(struct backlight_device *bd) 335 { 336 struct apple_gmux_data *gmux_data = bl_get_data(bd); 337 return gmux_read32(gmux_data, GMUX_PORT_BRIGHTNESS) & 338 GMUX_BRIGHTNESS_MASK; 339 } 340 341 static int gmux_update_status(struct backlight_device *bd) 342 { 343 struct apple_gmux_data *gmux_data = bl_get_data(bd); 344 u32 brightness = backlight_get_brightness(bd); 345 346 gmux_write32(gmux_data, GMUX_PORT_BRIGHTNESS, brightness); 347 348 return 0; 349 } 350 351 static const struct backlight_ops gmux_bl_ops = { 352 .options = BL_CORE_SUSPENDRESUME, 353 .get_brightness = gmux_get_brightness, 354 .update_status = gmux_update_status, 355 }; 356 357 /** 358 * DOC: Graphics mux 359 * 360 * On pre-retinas, the LVDS outputs of both GPUs feed into gmux which muxes 361 * either of them to the panel. One of the tricks gmux has up its sleeve is 362 * to lengthen the blanking interval of its output during a switch to 363 * synchronize it with the GPU switched to. This allows for a flicker-free 364 * switch that is imperceptible by the user (`US 8,687,007 B2`_). 365 * 366 * On retinas, muxing is no longer done by gmux itself, but by a separate 367 * chip which is controlled by gmux. The chip is triple sourced, it is 368 * either an `NXP CBTL06142`_, `TI HD3SS212`_ or `Pericom PI3VDP12412`_. 369 * The panel is driven with eDP instead of LVDS since the pixel clock 370 * required for retina resolution exceeds LVDS' limits. 371 * 372 * Pre-retinas are able to switch the panel's DDC pins separately. 373 * This is handled by a `TI SN74LV4066A`_ which is controlled by gmux. 374 * The inactive GPU can thus probe the panel's EDID without switching over 375 * the entire panel. Retinas lack this functionality as the chips used for 376 * eDP muxing are incapable of switching the AUX channel separately (see 377 * the linked data sheets, Pericom would be capable but this is unused). 378 * However the retina panel has the NO_AUX_HANDSHAKE_LINK_TRAINING bit set 379 * in its DPCD, allowing the inactive GPU to skip the AUX handshake and 380 * set up the output with link parameters pre-calibrated by the active GPU. 381 * 382 * The external DP port is only fully switchable on the first two unibody 383 * MacBook Pro generations, MBP5 2008/09 and MBP6 2010. This is done by an 384 * `NXP CBTL06141`_ which is controlled by gmux. It's the predecessor of the 385 * eDP mux on retinas, the difference being support for 2.7 versus 5.4 Gbit/s. 386 * 387 * The following MacBook Pro generations replaced the external DP port with a 388 * combined DP/Thunderbolt port and lost the ability to switch it between GPUs, 389 * connecting it either to the discrete GPU or the Thunderbolt controller. 390 * Oddly enough, while the full port is no longer switchable, AUX and HPD 391 * are still switchable by way of an `NXP CBTL03062`_ (on pre-retinas 392 * MBP8 2011 and MBP9 2012) or two `TI TS3DS10224`_ (on pre-t2 retinas) under 393 * the control of gmux. Since the integrated GPU is missing the main link, 394 * external displays appear to it as phantoms which fail to link-train. 395 * 396 * gmux receives the HPD signal of all display connectors and sends an 397 * interrupt on hotplug. On generations which cannot switch external ports, 398 * the discrete GPU can then be woken to drive the newly connected display. 399 * The ability to switch AUX on these generations could be used to improve 400 * reliability of hotplug detection by having the integrated GPU poll the 401 * ports while the discrete GPU is asleep, but currently we do not make use 402 * of this feature. 403 * 404 * Our switching policy for the external port is that on those generations 405 * which are able to switch it fully, the port is switched together with the 406 * panel when IGD / DIS commands are issued to vga_switcheroo. It is thus 407 * possible to drive e.g. a beamer on battery power with the integrated GPU. 408 * The user may manually switch to the discrete GPU if more performance is 409 * needed. 410 * 411 * On all newer generations, the external port can only be driven by the 412 * discrete GPU. If a display is plugged in while the panel is switched to 413 * the integrated GPU, *both* GPUs will be in use for maximum performance. 414 * To decrease power consumption, the user may manually switch to the 415 * discrete GPU, thereby suspending the integrated GPU. 416 * 417 * gmux' initial switch state on bootup is user configurable via the EFI 418 * variable ``gpu-power-prefs-fa4ce28d-b62f-4c99-9cc3-6815686e30f9`` (5th byte, 419 * 1 = IGD, 0 = DIS). Based on this setting, the EFI firmware tells gmux to 420 * switch the panel and the external DP connector and allocates a framebuffer 421 * for the selected GPU. 422 * 423 * .. _US 8,687,007 B2: https://pimg-fpiw.uspto.gov/fdd/07/870/086/0.pdf 424 * .. _NXP CBTL06141: https://www.nxp.com/documents/data_sheet/CBTL06141.pdf 425 * .. _NXP CBTL06142: https://www.nxp.com/documents/data_sheet/CBTL06141.pdf 426 * .. _TI HD3SS212: https://www.ti.com/lit/ds/symlink/hd3ss212.pdf 427 * .. _Pericom PI3VDP12412: https://www.pericom.com/assets/Datasheets/PI3VDP12412.pdf 428 * .. _TI SN74LV4066A: https://www.ti.com/lit/ds/symlink/sn74lv4066a.pdf 429 * .. _NXP CBTL03062: http://pdf.datasheetarchive.com/indexerfiles/Datasheets-SW16/DSASW00308511.pdf 430 * .. _TI TS3DS10224: https://www.ti.com/lit/ds/symlink/ts3ds10224.pdf 431 */ 432 433 static void gmux_read_switch_state(struct apple_gmux_data *gmux_data) 434 { 435 if (gmux_read8(gmux_data, GMUX_PORT_SWITCH_DDC) == 1) 436 gmux_data->switch_state_ddc = VGA_SWITCHEROO_IGD; 437 else 438 gmux_data->switch_state_ddc = VGA_SWITCHEROO_DIS; 439 440 if (gmux_read8(gmux_data, GMUX_PORT_SWITCH_DISPLAY) & 1) 441 gmux_data->switch_state_display = VGA_SWITCHEROO_DIS; 442 else 443 gmux_data->switch_state_display = VGA_SWITCHEROO_IGD; 444 445 if (gmux_read8(gmux_data, GMUX_PORT_SWITCH_EXTERNAL) == 2) 446 gmux_data->switch_state_external = VGA_SWITCHEROO_IGD; 447 else 448 gmux_data->switch_state_external = VGA_SWITCHEROO_DIS; 449 } 450 451 static void gmux_write_switch_state(struct apple_gmux_data *gmux_data) 452 { 453 if (gmux_data->switch_state_ddc == VGA_SWITCHEROO_IGD) 454 gmux_write8(gmux_data, GMUX_PORT_SWITCH_DDC, 1); 455 else 456 gmux_write8(gmux_data, GMUX_PORT_SWITCH_DDC, 2); 457 458 if (gmux_data->switch_state_display == VGA_SWITCHEROO_IGD) 459 gmux_write8(gmux_data, GMUX_PORT_SWITCH_DISPLAY, 2); 460 else 461 gmux_write8(gmux_data, GMUX_PORT_SWITCH_DISPLAY, 3); 462 463 if (gmux_data->switch_state_external == VGA_SWITCHEROO_IGD) 464 gmux_write8(gmux_data, GMUX_PORT_SWITCH_EXTERNAL, 2); 465 else 466 gmux_write8(gmux_data, GMUX_PORT_SWITCH_EXTERNAL, 3); 467 } 468 469 static int gmux_switchto(enum vga_switcheroo_client_id id) 470 { 471 apple_gmux_data->switch_state_ddc = id; 472 apple_gmux_data->switch_state_display = id; 473 if (apple_gmux_data->external_switchable) 474 apple_gmux_data->switch_state_external = id; 475 476 gmux_write_switch_state(apple_gmux_data); 477 478 return 0; 479 } 480 481 static int gmux_switch_ddc(enum vga_switcheroo_client_id id) 482 { 483 enum vga_switcheroo_client_id old_ddc_owner = 484 apple_gmux_data->switch_state_ddc; 485 486 if (id == old_ddc_owner) 487 return id; 488 489 pr_debug("Switching DDC from %d to %d\n", old_ddc_owner, id); 490 apple_gmux_data->switch_state_ddc = id; 491 492 if (id == VGA_SWITCHEROO_IGD) 493 gmux_write8(apple_gmux_data, GMUX_PORT_SWITCH_DDC, 1); 494 else 495 gmux_write8(apple_gmux_data, GMUX_PORT_SWITCH_DDC, 2); 496 497 return old_ddc_owner; 498 } 499 500 /** 501 * DOC: Power control 502 * 503 * gmux is able to cut power to the discrete GPU. It automatically takes care 504 * of the correct sequence to tear down and bring up the power rails for 505 * core voltage, VRAM and PCIe. 506 */ 507 508 static int gmux_set_discrete_state(struct apple_gmux_data *gmux_data, 509 enum vga_switcheroo_state state) 510 { 511 reinit_completion(&gmux_data->powerchange_done); 512 513 if (state == VGA_SWITCHEROO_ON) { 514 gmux_write8(gmux_data, GMUX_PORT_DISCRETE_POWER, 1); 515 gmux_write8(gmux_data, GMUX_PORT_DISCRETE_POWER, 3); 516 pr_debug("Discrete card powered up\n"); 517 } else { 518 gmux_write8(gmux_data, GMUX_PORT_DISCRETE_POWER, 1); 519 gmux_write8(gmux_data, GMUX_PORT_DISCRETE_POWER, 0); 520 pr_debug("Discrete card powered down\n"); 521 } 522 523 gmux_data->power_state = state; 524 525 if (gmux_data->gpe >= 0 && 526 !wait_for_completion_interruptible_timeout(&gmux_data->powerchange_done, 527 msecs_to_jiffies(200))) 528 pr_warn("Timeout waiting for gmux switch to complete\n"); 529 530 return 0; 531 } 532 533 static int gmux_set_power_state(enum vga_switcheroo_client_id id, 534 enum vga_switcheroo_state state) 535 { 536 if (id == VGA_SWITCHEROO_IGD) 537 return 0; 538 539 return gmux_set_discrete_state(apple_gmux_data, state); 540 } 541 542 static enum vga_switcheroo_client_id gmux_get_client_id(struct pci_dev *pdev) 543 { 544 /* 545 * Early Macbook Pros with switchable graphics use nvidia 546 * integrated graphics. Hardcode that the 9400M is integrated. 547 */ 548 if (pdev->vendor == PCI_VENDOR_ID_INTEL) 549 return VGA_SWITCHEROO_IGD; 550 else if (pdev->vendor == PCI_VENDOR_ID_NVIDIA && 551 pdev->device == 0x0863) 552 return VGA_SWITCHEROO_IGD; 553 else 554 return VGA_SWITCHEROO_DIS; 555 } 556 557 static const struct vga_switcheroo_handler gmux_handler_no_ddc = { 558 .switchto = gmux_switchto, 559 .power_state = gmux_set_power_state, 560 .get_client_id = gmux_get_client_id, 561 }; 562 563 static const struct vga_switcheroo_handler gmux_handler_ddc = { 564 .switchto = gmux_switchto, 565 .switch_ddc = gmux_switch_ddc, 566 .power_state = gmux_set_power_state, 567 .get_client_id = gmux_get_client_id, 568 }; 569 570 static const struct apple_gmux_config apple_gmux_pio = { 571 .read8 = &gmux_pio_read8, 572 .write8 = &gmux_pio_write8, 573 .read32 = &gmux_pio_read32, 574 .write32 = &gmux_pio_write32, 575 .gmux_handler = &gmux_handler_ddc, 576 .handler_flags = VGA_SWITCHEROO_CAN_SWITCH_DDC, 577 .resource_type = IORESOURCE_IO, 578 .read_version_as_u32 = false, 579 .name = "classic" 580 }; 581 582 static const struct apple_gmux_config apple_gmux_index = { 583 .read8 = &gmux_index_read8, 584 .write8 = &gmux_index_write8, 585 .read32 = &gmux_index_read32, 586 .write32 = &gmux_index_write32, 587 .gmux_handler = &gmux_handler_no_ddc, 588 .handler_flags = VGA_SWITCHEROO_NEEDS_EDP_CONFIG, 589 .resource_type = IORESOURCE_IO, 590 .read_version_as_u32 = true, 591 .name = "indexed" 592 }; 593 594 static const struct apple_gmux_config apple_gmux_mmio = { 595 .read8 = &gmux_mmio_read8, 596 .write8 = &gmux_mmio_write8, 597 .read32 = &gmux_mmio_read32, 598 .write32 = &gmux_mmio_write32, 599 .gmux_handler = &gmux_handler_no_ddc, 600 .handler_flags = VGA_SWITCHEROO_NEEDS_EDP_CONFIG, 601 .resource_type = IORESOURCE_MEM, 602 .read_version_as_u32 = true, 603 .name = "T2" 604 }; 605 606 607 /** 608 * DOC: Interrupt 609 * 610 * gmux is also connected to a GPIO pin of the southbridge and thereby is able 611 * to trigger an ACPI GPE. ACPI name GMGP holds this GPIO pin's number. On the 612 * MBP5 2008/09 it's GPIO pin 22 of the Nvidia MCP79, on following generations 613 * it's GPIO pin 6 of the Intel PCH, on MMIO gmux's it's pin 21. 614 * 615 * The GPE merely signals that an interrupt occurred, the actual type of event 616 * is identified by reading a gmux register. 617 * 618 * In addition to the GMGP name, gmux's ACPI device also has two methods GMSP 619 * and GMLV. GMLV likely means "GMUX Level", and reads the value of the GPIO, 620 * while GMSP likely means "GMUX Set Polarity", and seems to write to the GPIO's 621 * value. On newer Macbooks (This was introduced with or sometime before the 622 * MacBookPro14,3), the ACPI GPE method differentiates between the OS type: On 623 * Darwin, only a notification is signaled, whereas on other OSes, the GPIO's 624 * value is read and then inverted. 625 * 626 * Because Linux masquerades as Darwin, it ends up in the notification-only code 627 * path. On MMIO gmux's, this seems to lead to us being unable to clear interrupts, 628 * unless we call GMSP(0). Without this, there is a flood of status=0 interrupts 629 * that can't be cleared. This issue seems to be unique to MMIO gmux's. 630 */ 631 632 static inline void gmux_disable_interrupts(struct apple_gmux_data *gmux_data) 633 { 634 gmux_write8(gmux_data, GMUX_PORT_INTERRUPT_ENABLE, 635 GMUX_INTERRUPT_DISABLE); 636 } 637 638 static inline void gmux_enable_interrupts(struct apple_gmux_data *gmux_data) 639 { 640 gmux_write8(gmux_data, GMUX_PORT_INTERRUPT_ENABLE, 641 GMUX_INTERRUPT_ENABLE); 642 } 643 644 static inline u8 gmux_interrupt_get_status(struct apple_gmux_data *gmux_data) 645 { 646 return gmux_read8(gmux_data, GMUX_PORT_INTERRUPT_STATUS); 647 } 648 649 static void gmux_clear_interrupts(struct apple_gmux_data *gmux_data) 650 { 651 u8 status; 652 653 /* to clear interrupts write back current status */ 654 status = gmux_interrupt_get_status(gmux_data); 655 gmux_write8(gmux_data, GMUX_PORT_INTERRUPT_STATUS, status); 656 /* Prevent flood of status=0 interrupts */ 657 if (gmux_data->config == &apple_gmux_mmio) 658 acpi_execute_simple_method(gmux_data->dhandle, "GMSP", 0); 659 } 660 661 static void gmux_notify_handler(acpi_handle device, u32 value, void *context) 662 { 663 u8 status; 664 struct pnp_dev *pnp = (struct pnp_dev *)context; 665 struct apple_gmux_data *gmux_data = pnp_get_drvdata(pnp); 666 667 status = gmux_interrupt_get_status(gmux_data); 668 gmux_disable_interrupts(gmux_data); 669 pr_debug("Notify handler called: status %d\n", status); 670 671 gmux_clear_interrupts(gmux_data); 672 gmux_enable_interrupts(gmux_data); 673 674 if (status & GMUX_INTERRUPT_STATUS_POWER) 675 complete(&gmux_data->powerchange_done); 676 } 677 678 /** 679 * DOC: Debugfs Interface 680 * 681 * gmux ports can be accessed from userspace as a debugfs interface. For example: 682 * 683 * # echo 4 > /sys/kernel/debug/apple_gmux/selected_port 684 * # cat /sys/kernel/debug/apple_gmux/selected_port_data | xxd -p 685 * 00000005 686 * 687 * Reads 4 bytes from port 4 (GMUX_PORT_VERSION_MAJOR). 688 * 689 * 1 and 4 byte writes are also allowed. 690 */ 691 692 static ssize_t gmux_selected_port_data_write(struct file *file, 693 const char __user *userbuf, size_t count, loff_t *ppos) 694 { 695 struct apple_gmux_data *gmux_data = file->private_data; 696 697 if (*ppos) 698 return -EINVAL; 699 700 if (count == 1) { 701 u8 data; 702 703 if (copy_from_user(&data, userbuf, 1)) 704 return -EFAULT; 705 706 gmux_write8(gmux_data, gmux_data->selected_port, data); 707 } else if (count == 4) { 708 u32 data; 709 710 if (copy_from_user(&data, userbuf, 4)) 711 return -EFAULT; 712 713 gmux_write32(gmux_data, gmux_data->selected_port, data); 714 } else 715 return -EINVAL; 716 717 return count; 718 } 719 720 static ssize_t gmux_selected_port_data_read(struct file *file, 721 char __user *userbuf, size_t count, loff_t *ppos) 722 { 723 struct apple_gmux_data *gmux_data = file->private_data; 724 u32 data; 725 726 data = gmux_read32(gmux_data, gmux_data->selected_port); 727 728 return simple_read_from_buffer(userbuf, count, ppos, &data, sizeof(data)); 729 } 730 731 static const struct file_operations gmux_port_data_ops = { 732 .open = simple_open, 733 .write = gmux_selected_port_data_write, 734 .read = gmux_selected_port_data_read 735 }; 736 737 static void gmux_init_debugfs(struct apple_gmux_data *gmux_data) 738 { 739 gmux_data->debug_dentry = debugfs_create_dir(KBUILD_MODNAME, NULL); 740 741 debugfs_create_u8("selected_port", 0644, gmux_data->debug_dentry, 742 &gmux_data->selected_port); 743 debugfs_create_file("selected_port_data", 0644, gmux_data->debug_dentry, 744 gmux_data, &gmux_port_data_ops); 745 } 746 747 static void gmux_fini_debugfs(struct apple_gmux_data *gmux_data) 748 { 749 debugfs_remove_recursive(gmux_data->debug_dentry); 750 } 751 752 static int gmux_suspend(struct device *dev) 753 { 754 struct pnp_dev *pnp = to_pnp_dev(dev); 755 struct apple_gmux_data *gmux_data = pnp_get_drvdata(pnp); 756 757 gmux_disable_interrupts(gmux_data); 758 return 0; 759 } 760 761 static int gmux_resume(struct device *dev) 762 { 763 struct pnp_dev *pnp = to_pnp_dev(dev); 764 struct apple_gmux_data *gmux_data = pnp_get_drvdata(pnp); 765 766 gmux_enable_interrupts(gmux_data); 767 gmux_write_switch_state(gmux_data); 768 if (gmux_data->power_state == VGA_SWITCHEROO_OFF) 769 gmux_set_discrete_state(gmux_data, gmux_data->power_state); 770 return 0; 771 } 772 773 static int is_thunderbolt(struct device *dev, void *data) 774 { 775 return to_pci_dev(dev)->is_thunderbolt; 776 } 777 778 static int gmux_probe(struct pnp_dev *pnp, const struct pnp_device_id *id) 779 { 780 struct apple_gmux_data *gmux_data; 781 struct resource *res; 782 struct backlight_properties props; 783 struct backlight_device *bdev = NULL; 784 u8 ver_major, ver_minor, ver_release; 785 bool register_bdev = true; 786 int ret = -ENXIO; 787 acpi_status status; 788 unsigned long long gpe; 789 enum apple_gmux_type type; 790 u32 version; 791 792 if (apple_gmux_data) 793 return -EBUSY; 794 795 if (!apple_gmux_detect(pnp, &type)) { 796 pr_info("gmux device not present\n"); 797 return -ENODEV; 798 } 799 800 gmux_data = kzalloc(sizeof(*gmux_data), GFP_KERNEL); 801 if (!gmux_data) 802 return -ENOMEM; 803 pnp_set_drvdata(pnp, gmux_data); 804 805 switch (type) { 806 case APPLE_GMUX_TYPE_MMIO: 807 gmux_data->config = &apple_gmux_mmio; 808 mutex_init(&gmux_data->index_lock); 809 810 res = pnp_get_resource(pnp, IORESOURCE_MEM, 0); 811 gmux_data->iostart = res->start; 812 /* Although the ACPI table only allocates 8 bytes, we need 16. */ 813 gmux_data->iolen = 16; 814 if (!request_mem_region(gmux_data->iostart, gmux_data->iolen, 815 "Apple gmux")) { 816 pr_err("gmux I/O already in use\n"); 817 goto err_free; 818 } 819 gmux_data->iomem_base = ioremap(gmux_data->iostart, gmux_data->iolen); 820 if (!gmux_data->iomem_base) { 821 pr_err("couldn't remap gmux mmio region"); 822 goto err_release; 823 } 824 goto get_version; 825 case APPLE_GMUX_TYPE_INDEXED: 826 gmux_data->config = &apple_gmux_index; 827 mutex_init(&gmux_data->index_lock); 828 break; 829 case APPLE_GMUX_TYPE_PIO: 830 gmux_data->config = &apple_gmux_pio; 831 break; 832 } 833 834 res = pnp_get_resource(pnp, IORESOURCE_IO, 0); 835 gmux_data->iostart = res->start; 836 gmux_data->iolen = resource_size(res); 837 838 if (!request_region(gmux_data->iostart, gmux_data->iolen, 839 "Apple gmux")) { 840 pr_err("gmux I/O already in use\n"); 841 goto err_free; 842 } 843 844 get_version: 845 if (gmux_data->config->read_version_as_u32) { 846 version = gmux_read32(gmux_data, GMUX_PORT_VERSION_MAJOR); 847 ver_major = (version >> 24) & 0xff; 848 ver_minor = (version >> 16) & 0xff; 849 ver_release = (version >> 8) & 0xff; 850 } else { 851 ver_major = gmux_read8(gmux_data, GMUX_PORT_VERSION_MAJOR); 852 ver_minor = gmux_read8(gmux_data, GMUX_PORT_VERSION_MINOR); 853 ver_release = gmux_read8(gmux_data, GMUX_PORT_VERSION_RELEASE); 854 } 855 pr_info("Found gmux version %d.%d.%d [%s]\n", ver_major, ver_minor, 856 ver_release, gmux_data->config->name); 857 858 memset(&props, 0, sizeof(props)); 859 props.type = BACKLIGHT_PLATFORM; 860 props.max_brightness = gmux_read32(gmux_data, GMUX_PORT_MAX_BRIGHTNESS); 861 862 #if IS_REACHABLE(CONFIG_ACPI_VIDEO) 863 register_bdev = acpi_video_get_backlight_type() == acpi_backlight_apple_gmux; 864 #endif 865 if (register_bdev) { 866 /* 867 * Currently it's assumed that the maximum brightness is less than 868 * 2^24 for compatibility with old gmux versions. Cap the max 869 * brightness at this value, but print a warning if the hardware 870 * reports something higher so that it can be fixed. 871 */ 872 if (WARN_ON(props.max_brightness > GMUX_MAX_BRIGHTNESS)) 873 props.max_brightness = GMUX_MAX_BRIGHTNESS; 874 875 bdev = backlight_device_register("gmux_backlight", &pnp->dev, 876 gmux_data, &gmux_bl_ops, &props); 877 if (IS_ERR(bdev)) { 878 ret = PTR_ERR(bdev); 879 goto err_unmap; 880 } 881 882 gmux_data->bdev = bdev; 883 bdev->props.brightness = gmux_get_brightness(bdev); 884 backlight_update_status(bdev); 885 } 886 887 gmux_data->power_state = VGA_SWITCHEROO_ON; 888 889 gmux_data->dhandle = ACPI_HANDLE(&pnp->dev); 890 if (!gmux_data->dhandle) { 891 pr_err("Cannot find acpi handle for pnp device %s\n", 892 dev_name(&pnp->dev)); 893 ret = -ENODEV; 894 goto err_notify; 895 } 896 897 status = acpi_evaluate_integer(gmux_data->dhandle, "GMGP", NULL, &gpe); 898 if (ACPI_SUCCESS(status)) { 899 gmux_data->gpe = (int)gpe; 900 901 status = acpi_install_notify_handler(gmux_data->dhandle, 902 ACPI_DEVICE_NOTIFY, 903 &gmux_notify_handler, pnp); 904 if (ACPI_FAILURE(status)) { 905 pr_err("Install notify handler failed: %s\n", 906 acpi_format_exception(status)); 907 ret = -ENODEV; 908 goto err_notify; 909 } 910 911 status = acpi_enable_gpe(NULL, gmux_data->gpe); 912 if (ACPI_FAILURE(status)) { 913 pr_err("Cannot enable gpe: %s\n", 914 acpi_format_exception(status)); 915 goto err_enable_gpe; 916 } 917 } else { 918 pr_warn("No GPE found for gmux\n"); 919 gmux_data->gpe = -1; 920 } 921 922 /* 923 * If Thunderbolt is present, the external DP port is not fully 924 * switchable. Force its AUX channel to the discrete GPU. 925 */ 926 gmux_data->external_switchable = 927 !bus_for_each_dev(&pci_bus_type, NULL, NULL, is_thunderbolt); 928 if (!gmux_data->external_switchable) 929 gmux_write8(gmux_data, GMUX_PORT_SWITCH_EXTERNAL, 3); 930 931 apple_gmux_data = gmux_data; 932 init_completion(&gmux_data->powerchange_done); 933 gmux_enable_interrupts(gmux_data); 934 gmux_read_switch_state(gmux_data); 935 936 /* 937 * Retina MacBook Pros cannot switch the panel's AUX separately 938 * and need eDP pre-calibration. They are distinguishable from 939 * pre-retinas by having an "indexed" or "T2" gmux. 940 * 941 * Pre-retina MacBook Pros can switch the panel's DDC separately. 942 */ 943 ret = vga_switcheroo_register_handler(gmux_data->config->gmux_handler, 944 gmux_data->config->handler_flags); 945 if (ret) { 946 pr_err("Failed to register vga_switcheroo handler\n"); 947 goto err_register_handler; 948 } 949 950 gmux_init_debugfs(gmux_data); 951 return 0; 952 953 err_register_handler: 954 gmux_disable_interrupts(gmux_data); 955 apple_gmux_data = NULL; 956 if (gmux_data->gpe >= 0) 957 acpi_disable_gpe(NULL, gmux_data->gpe); 958 err_enable_gpe: 959 if (gmux_data->gpe >= 0) 960 acpi_remove_notify_handler(gmux_data->dhandle, 961 ACPI_DEVICE_NOTIFY, 962 &gmux_notify_handler); 963 err_notify: 964 backlight_device_unregister(bdev); 965 err_unmap: 966 if (gmux_data->iomem_base) 967 iounmap(gmux_data->iomem_base); 968 err_release: 969 if (gmux_data->config->resource_type == IORESOURCE_MEM) 970 release_mem_region(gmux_data->iostart, gmux_data->iolen); 971 else 972 release_region(gmux_data->iostart, gmux_data->iolen); 973 err_free: 974 kfree(gmux_data); 975 return ret; 976 } 977 978 static void gmux_remove(struct pnp_dev *pnp) 979 { 980 struct apple_gmux_data *gmux_data = pnp_get_drvdata(pnp); 981 982 gmux_fini_debugfs(gmux_data); 983 vga_switcheroo_unregister_handler(); 984 gmux_disable_interrupts(gmux_data); 985 if (gmux_data->gpe >= 0) { 986 acpi_disable_gpe(NULL, gmux_data->gpe); 987 acpi_remove_notify_handler(gmux_data->dhandle, 988 ACPI_DEVICE_NOTIFY, 989 &gmux_notify_handler); 990 } 991 992 backlight_device_unregister(gmux_data->bdev); 993 994 if (gmux_data->iomem_base) { 995 iounmap(gmux_data->iomem_base); 996 release_mem_region(gmux_data->iostart, gmux_data->iolen); 997 } else 998 release_region(gmux_data->iostart, gmux_data->iolen); 999 apple_gmux_data = NULL; 1000 kfree(gmux_data); 1001 } 1002 1003 static const struct pnp_device_id gmux_device_ids[] = { 1004 {GMUX_ACPI_HID, 0}, 1005 {"", 0} 1006 }; 1007 1008 static const struct dev_pm_ops gmux_dev_pm_ops = { 1009 .suspend = gmux_suspend, 1010 .resume = gmux_resume, 1011 }; 1012 1013 static struct pnp_driver gmux_pnp_driver = { 1014 .name = "apple-gmux", 1015 .probe = gmux_probe, 1016 .remove = gmux_remove, 1017 .id_table = gmux_device_ids, 1018 .driver = { 1019 .pm = &gmux_dev_pm_ops, 1020 }, 1021 }; 1022 1023 module_pnp_driver(gmux_pnp_driver); 1024 MODULE_AUTHOR("Seth Forshee <seth.forshee@canonical.com>"); 1025 MODULE_DESCRIPTION("Apple Gmux Driver"); 1026 MODULE_LICENSE("GPL"); 1027 MODULE_DEVICE_TABLE(pnp, gmux_device_ids); 1028