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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * Gmux driver for Apple laptops4 *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 ": " fmt12 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: Overview30 *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 has35 * an I2C connection to a `NXP PCAL6524` GPIO expander, which enables/disables36 * 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 with38 * 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 has41 * dual GPUs but no built-in display.)42 *43 * gmux is connected to the LPC bus of the southbridge. Its I/O ports are44 * accessed differently depending on the microcontroller: Driver functions45 * to access a pre-retina gmux are infixed ``_pio_``, those for a pre-T246 * retina gmux are infixed ``_index_``, and those on T2 Macs are infixed47 * with ``_mmio_``.48 *49 * .. _Lattice XP2:50 * http://www.latticesemi.com/en/Products/FPGAandCPLD/LatticeXP2.aspx51 * .. _Renesas R4F2113:52 * http://www.renesas.com/products/mpumcu/h8s/h8s2100/h8s2113/index.jsp53 * .. _NXP PCAL6524:54 * https://www.nxp.com/docs/en/data-sheet/PCAL6524.pdf55 */56 57struct apple_gmux_config;58 59struct 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 83static struct apple_gmux_data *apple_gmux_data;84 85struct 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 0xff98#define GMUX_INTERRUPT_DISABLE 0x0099 100#define GMUX_INTERRUPT_STATUS_ACTIVE 0101#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 0x00ffffff106#define GMUX_MAX_BRIGHTNESS GMUX_BRIGHTNESS_MASK107 108# define MMIO_GMUX_MAX_BRIGHTNESS 0xffff109 110static u8 gmux_pio_read8(struct apple_gmux_data *gmux_data, int port)111{112 return inb(gmux_data->iostart + port);113}114 115static void gmux_pio_write8(struct apple_gmux_data *gmux_data, int port,116 u8 val)117{118 outb(val, gmux_data->iostart + port);119}120 121static u32 gmux_pio_read32(struct apple_gmux_data *gmux_data, int port)122{123 return inl(gmux_data->iostart + port);124}125 126static void gmux_pio_write32(struct apple_gmux_data *gmux_data, int port,127 u32 val)128{129 int i;130 u8 tmpval;131 132 for (i = 0; i < 4; i++) {133 tmpval = (val >> (i * 8)) & 0xff;134 outb(tmpval, gmux_data->iostart + port + i);135 }136}137 138static int gmux_index_wait_ready(struct apple_gmux_data *gmux_data)139{140 int i = 200;141 u8 gwr = inb(gmux_data->iostart + GMUX_PORT_WRITE);142 143 while (i && (gwr & 0x01)) {144 inb(gmux_data->iostart + GMUX_PORT_READ);145 gwr = inb(gmux_data->iostart + GMUX_PORT_WRITE);146 udelay(100);147 i--;148 }149 150 return !!i;151}152 153static int gmux_index_wait_complete(struct apple_gmux_data *gmux_data)154{155 int i = 200;156 u8 gwr = inb(gmux_data->iostart + GMUX_PORT_WRITE);157 158 while (i && !(gwr & 0x01)) {159 gwr = inb(gmux_data->iostart + GMUX_PORT_WRITE);160 udelay(100);161 i--;162 }163 164 if (gwr & 0x01)165 inb(gmux_data->iostart + GMUX_PORT_READ);166 167 return !!i;168}169 170static u8 gmux_index_read8(struct apple_gmux_data *gmux_data, int port)171{172 u8 val;173 174 mutex_lock(&gmux_data->index_lock);175 gmux_index_wait_ready(gmux_data);176 outb((port & 0xff), gmux_data->iostart + GMUX_PORT_READ);177 gmux_index_wait_complete(gmux_data);178 val = inb(gmux_data->iostart + GMUX_PORT_VALUE);179 mutex_unlock(&gmux_data->index_lock);180 181 return val;182}183 184static void gmux_index_write8(struct apple_gmux_data *gmux_data, int port,185 u8 val)186{187 mutex_lock(&gmux_data->index_lock);188 outb(val, gmux_data->iostart + GMUX_PORT_VALUE);189 gmux_index_wait_ready(gmux_data);190 outb(port & 0xff, gmux_data->iostart + GMUX_PORT_WRITE);191 gmux_index_wait_complete(gmux_data);192 mutex_unlock(&gmux_data->index_lock);193}194 195static u32 gmux_index_read32(struct apple_gmux_data *gmux_data, int port)196{197 u32 val;198 199 mutex_lock(&gmux_data->index_lock);200 gmux_index_wait_ready(gmux_data);201 outb((port & 0xff), gmux_data->iostart + GMUX_PORT_READ);202 gmux_index_wait_complete(gmux_data);203 val = inl(gmux_data->iostart + GMUX_PORT_VALUE);204 mutex_unlock(&gmux_data->index_lock);205 206 return val;207}208 209static void gmux_index_write32(struct apple_gmux_data *gmux_data, int port,210 u32 val)211{212 int i;213 u8 tmpval;214 215 mutex_lock(&gmux_data->index_lock);216 217 for (i = 0; i < 4; i++) {218 tmpval = (val >> (i * 8)) & 0xff;219 outb(tmpval, gmux_data->iostart + GMUX_PORT_VALUE + i);220 }221 222 gmux_index_wait_ready(gmux_data);223 outb(port & 0xff, gmux_data->iostart + GMUX_PORT_WRITE);224 gmux_index_wait_complete(gmux_data);225 mutex_unlock(&gmux_data->index_lock);226}227 228static int gmux_mmio_wait(struct apple_gmux_data *gmux_data)229{230 int i = 200;231 u8 gwr = ioread8(gmux_data->iomem_base + GMUX_MMIO_COMMAND_SEND);232 233 while (i && gwr) {234 gwr = ioread8(gmux_data->iomem_base + GMUX_MMIO_COMMAND_SEND);235 udelay(100);236 i--;237 }238 239 return !!i;240}241 242static u8 gmux_mmio_read8(struct apple_gmux_data *gmux_data, int port)243{244 u8 val;245 246 mutex_lock(&gmux_data->index_lock);247 gmux_mmio_wait(gmux_data);248 iowrite8((port & 0xff), gmux_data->iomem_base + GMUX_MMIO_PORT_SELECT);249 iowrite8(GMUX_MMIO_READ | sizeof(val),250 gmux_data->iomem_base + GMUX_MMIO_COMMAND_SEND);251 gmux_mmio_wait(gmux_data);252 val = ioread8(gmux_data->iomem_base);253 mutex_unlock(&gmux_data->index_lock);254 255 return val;256}257 258static void gmux_mmio_write8(struct apple_gmux_data *gmux_data, int port,259 u8 val)260{261 mutex_lock(&gmux_data->index_lock);262 gmux_mmio_wait(gmux_data);263 iowrite8(val, gmux_data->iomem_base);264 265 iowrite8(port & 0xff, gmux_data->iomem_base + GMUX_MMIO_PORT_SELECT);266 iowrite8(GMUX_MMIO_WRITE | sizeof(val),267 gmux_data->iomem_base + GMUX_MMIO_COMMAND_SEND);268 269 gmux_mmio_wait(gmux_data);270 mutex_unlock(&gmux_data->index_lock);271}272 273static u32 gmux_mmio_read32(struct apple_gmux_data *gmux_data, int port)274{275 u32 val;276 277 mutex_lock(&gmux_data->index_lock);278 gmux_mmio_wait(gmux_data);279 iowrite8((port & 0xff), gmux_data->iomem_base + GMUX_MMIO_PORT_SELECT);280 iowrite8(GMUX_MMIO_READ | sizeof(val),281 gmux_data->iomem_base + GMUX_MMIO_COMMAND_SEND);282 gmux_mmio_wait(gmux_data);283 val = ioread32be(gmux_data->iomem_base);284 mutex_unlock(&gmux_data->index_lock);285 286 return val;287}288 289static void gmux_mmio_write32(struct apple_gmux_data *gmux_data, int port,290 u32 val)291{292 mutex_lock(&gmux_data->index_lock);293 iowrite32be(val, gmux_data->iomem_base);294 iowrite8(port & 0xff, gmux_data->iomem_base + GMUX_MMIO_PORT_SELECT);295 iowrite8(GMUX_MMIO_WRITE | sizeof(val),296 gmux_data->iomem_base + GMUX_MMIO_COMMAND_SEND);297 gmux_mmio_wait(gmux_data);298 mutex_unlock(&gmux_data->index_lock);299}300 301static u8 gmux_read8(struct apple_gmux_data *gmux_data, int port)302{303 return gmux_data->config->read8(gmux_data, port);304}305 306static void gmux_write8(struct apple_gmux_data *gmux_data, int port, u8 val)307{308 return gmux_data->config->write8(gmux_data, port, val);309}310 311static u32 gmux_read32(struct apple_gmux_data *gmux_data, int port)312{313 return gmux_data->config->read32(gmux_data, port);314}315 316static void gmux_write32(struct apple_gmux_data *gmux_data, int port,317 u32 val)318{319 return gmux_data->config->write32(gmux_data, port, val);320}321 322/**323 * DOC: Backlight control324 *325 * On single GPU MacBooks, the PWM signal for the backlight is generated by326 * the GPU. On dual GPU MacBook Pros by contrast, either GPU may be suspended327 * to conserve energy. Hence the PWM signal needs to be generated by a separate328 * backlight driver which is controlled by gmux. The earliest generation329 * MBP5 2008/09 uses a `TI LP8543`_ backlight driver. Newer models330 * use a `TI LP8545`_ or a TI LP8548.331 *332 * .. _TI LP8543: https://www.ti.com/lit/ds/symlink/lp8543.pdf333 * .. _TI LP8545: https://www.ti.com/lit/ds/symlink/lp8545.pdf334 */335 336static int gmux_get_brightness(struct backlight_device *bd)337{338 struct apple_gmux_data *gmux_data = bl_get_data(bd);339 return gmux_read32(gmux_data, GMUX_PORT_BRIGHTNESS) &340 GMUX_BRIGHTNESS_MASK;341}342 343static int gmux_update_status(struct backlight_device *bd)344{345 struct apple_gmux_data *gmux_data = bl_get_data(bd);346 u32 brightness = backlight_get_brightness(bd);347 348 gmux_write32(gmux_data, GMUX_PORT_BRIGHTNESS, brightness);349 350 return 0;351}352 353static const struct backlight_ops gmux_bl_ops = {354 .options = BL_CORE_SUSPENDRESUME,355 .get_brightness = gmux_get_brightness,356 .update_status = gmux_update_status,357};358 359/**360 * DOC: Graphics mux361 *362 * On pre-retinas, the LVDS outputs of both GPUs feed into gmux which muxes363 * either of them to the panel. One of the tricks gmux has up its sleeve is364 * to lengthen the blanking interval of its output during a switch to365 * synchronize it with the GPU switched to. This allows for a flicker-free366 * switch that is imperceptible by the user (`US 8,687,007 B2`_).367 *368 * On retinas, muxing is no longer done by gmux itself, but by a separate369 * chip which is controlled by gmux. The chip is triple sourced, it is370 * either an `NXP CBTL06142`_, `TI HD3SS212`_ or `Pericom PI3VDP12412`_.371 * The panel is driven with eDP instead of LVDS since the pixel clock372 * required for retina resolution exceeds LVDS' limits.373 *374 * Pre-retinas are able to switch the panel's DDC pins separately.375 * This is handled by a `TI SN74LV4066A`_ which is controlled by gmux.376 * The inactive GPU can thus probe the panel's EDID without switching over377 * the entire panel. Retinas lack this functionality as the chips used for378 * eDP muxing are incapable of switching the AUX channel separately (see379 * the linked data sheets, Pericom would be capable but this is unused).380 * However the retina panel has the NO_AUX_HANDSHAKE_LINK_TRAINING bit set381 * in its DPCD, allowing the inactive GPU to skip the AUX handshake and382 * set up the output with link parameters pre-calibrated by the active GPU.383 *384 * The external DP port is only fully switchable on the first two unibody385 * MacBook Pro generations, MBP5 2008/09 and MBP6 2010. This is done by an386 * `NXP CBTL06141`_ which is controlled by gmux. It's the predecessor of the387 * eDP mux on retinas, the difference being support for 2.7 versus 5.4 Gbit/s.388 *389 * The following MacBook Pro generations replaced the external DP port with a390 * combined DP/Thunderbolt port and lost the ability to switch it between GPUs,391 * connecting it either to the discrete GPU or the Thunderbolt controller.392 * Oddly enough, while the full port is no longer switchable, AUX and HPD393 * are still switchable by way of an `NXP CBTL03062`_ (on pre-retinas394 * MBP8 2011 and MBP9 2012) or two `TI TS3DS10224`_ (on pre-t2 retinas) under395 * the control of gmux. Since the integrated GPU is missing the main link,396 * external displays appear to it as phantoms which fail to link-train.397 *398 * gmux receives the HPD signal of all display connectors and sends an399 * interrupt on hotplug. On generations which cannot switch external ports,400 * the discrete GPU can then be woken to drive the newly connected display.401 * The ability to switch AUX on these generations could be used to improve402 * reliability of hotplug detection by having the integrated GPU poll the403 * ports while the discrete GPU is asleep, but currently we do not make use404 * of this feature.405 *406 * Our switching policy for the external port is that on those generations407 * which are able to switch it fully, the port is switched together with the408 * panel when IGD / DIS commands are issued to vga_switcheroo. It is thus409 * possible to drive e.g. a beamer on battery power with the integrated GPU.410 * The user may manually switch to the discrete GPU if more performance is411 * needed.412 *413 * On all newer generations, the external port can only be driven by the414 * discrete GPU. If a display is plugged in while the panel is switched to415 * the integrated GPU, *both* GPUs will be in use for maximum performance.416 * To decrease power consumption, the user may manually switch to the417 * discrete GPU, thereby suspending the integrated GPU.418 *419 * gmux' initial switch state on bootup is user configurable via the EFI420 * variable ``gpu-power-prefs-fa4ce28d-b62f-4c99-9cc3-6815686e30f9`` (5th byte,421 * 1 = IGD, 0 = DIS). Based on this setting, the EFI firmware tells gmux to422 * switch the panel and the external DP connector and allocates a framebuffer423 * for the selected GPU.424 *425 * .. _US 8,687,007 B2: https://pimg-fpiw.uspto.gov/fdd/07/870/086/0.pdf426 * .. _NXP CBTL06141: https://www.nxp.com/documents/data_sheet/CBTL06141.pdf427 * .. _NXP CBTL06142: https://www.nxp.com/documents/data_sheet/CBTL06141.pdf428 * .. _TI HD3SS212: https://www.ti.com/lit/ds/symlink/hd3ss212.pdf429 * .. _Pericom PI3VDP12412: https://www.pericom.com/assets/Datasheets/PI3VDP12412.pdf430 * .. _TI SN74LV4066A: https://www.ti.com/lit/ds/symlink/sn74lv4066a.pdf431 * .. _NXP CBTL03062: http://pdf.datasheetarchive.com/indexerfiles/Datasheets-SW16/DSASW00308511.pdf432 * .. _TI TS3DS10224: https://www.ti.com/lit/ds/symlink/ts3ds10224.pdf433 */434 435static void gmux_read_switch_state(struct apple_gmux_data *gmux_data)436{437 if (gmux_read8(gmux_data, GMUX_PORT_SWITCH_DDC) == 1)438 gmux_data->switch_state_ddc = VGA_SWITCHEROO_IGD;439 else440 gmux_data->switch_state_ddc = VGA_SWITCHEROO_DIS;441 442 if (gmux_read8(gmux_data, GMUX_PORT_SWITCH_DISPLAY) & 1)443 gmux_data->switch_state_display = VGA_SWITCHEROO_DIS;444 else445 gmux_data->switch_state_display = VGA_SWITCHEROO_IGD;446 447 if (gmux_read8(gmux_data, GMUX_PORT_SWITCH_EXTERNAL) == 2)448 gmux_data->switch_state_external = VGA_SWITCHEROO_IGD;449 else450 gmux_data->switch_state_external = VGA_SWITCHEROO_DIS;451}452 453static void gmux_write_switch_state(struct apple_gmux_data *gmux_data)454{455 if (gmux_data->switch_state_ddc == VGA_SWITCHEROO_IGD)456 gmux_write8(gmux_data, GMUX_PORT_SWITCH_DDC, 1);457 else458 gmux_write8(gmux_data, GMUX_PORT_SWITCH_DDC, 2);459 460 if (gmux_data->switch_state_display == VGA_SWITCHEROO_IGD)461 gmux_write8(gmux_data, GMUX_PORT_SWITCH_DISPLAY, 2);462 else463 gmux_write8(gmux_data, GMUX_PORT_SWITCH_DISPLAY, 3);464 465 if (gmux_data->switch_state_external == VGA_SWITCHEROO_IGD)466 gmux_write8(gmux_data, GMUX_PORT_SWITCH_EXTERNAL, 2);467 else468 gmux_write8(gmux_data, GMUX_PORT_SWITCH_EXTERNAL, 3);469}470 471static int gmux_switchto(enum vga_switcheroo_client_id id)472{473 apple_gmux_data->switch_state_ddc = id;474 apple_gmux_data->switch_state_display = id;475 if (apple_gmux_data->external_switchable)476 apple_gmux_data->switch_state_external = id;477 478 gmux_write_switch_state(apple_gmux_data);479 480 return 0;481}482 483static int gmux_switch_ddc(enum vga_switcheroo_client_id id)484{485 enum vga_switcheroo_client_id old_ddc_owner =486 apple_gmux_data->switch_state_ddc;487 488 if (id == old_ddc_owner)489 return id;490 491 pr_debug("Switching DDC from %d to %d\n", old_ddc_owner, id);492 apple_gmux_data->switch_state_ddc = id;493 494 if (id == VGA_SWITCHEROO_IGD)495 gmux_write8(apple_gmux_data, GMUX_PORT_SWITCH_DDC, 1);496 else497 gmux_write8(apple_gmux_data, GMUX_PORT_SWITCH_DDC, 2);498 499 return old_ddc_owner;500}501 502/**503 * DOC: Power control504 *505 * gmux is able to cut power to the discrete GPU. It automatically takes care506 * of the correct sequence to tear down and bring up the power rails for507 * core voltage, VRAM and PCIe.508 */509 510static int gmux_set_discrete_state(struct apple_gmux_data *gmux_data,511 enum vga_switcheroo_state state)512{513 reinit_completion(&gmux_data->powerchange_done);514 515 if (state == VGA_SWITCHEROO_ON) {516 gmux_write8(gmux_data, GMUX_PORT_DISCRETE_POWER, 1);517 gmux_write8(gmux_data, GMUX_PORT_DISCRETE_POWER, 3);518 pr_debug("Discrete card powered up\n");519 } else {520 gmux_write8(gmux_data, GMUX_PORT_DISCRETE_POWER, 1);521 gmux_write8(gmux_data, GMUX_PORT_DISCRETE_POWER, 0);522 pr_debug("Discrete card powered down\n");523 }524 525 gmux_data->power_state = state;526 527 if (gmux_data->gpe >= 0 &&528 !wait_for_completion_interruptible_timeout(&gmux_data->powerchange_done,529 msecs_to_jiffies(200)))530 pr_warn("Timeout waiting for gmux switch to complete\n");531 532 return 0;533}534 535static int gmux_set_power_state(enum vga_switcheroo_client_id id,536 enum vga_switcheroo_state state)537{538 if (id == VGA_SWITCHEROO_IGD)539 return 0;540 541 return gmux_set_discrete_state(apple_gmux_data, state);542}543 544static enum vga_switcheroo_client_id gmux_get_client_id(struct pci_dev *pdev)545{546 /*547 * Early Macbook Pros with switchable graphics use nvidia548 * integrated graphics. Hardcode that the 9400M is integrated.549 */550 if (pdev->vendor == PCI_VENDOR_ID_INTEL)551 return VGA_SWITCHEROO_IGD;552 else if (pdev->vendor == PCI_VENDOR_ID_NVIDIA &&553 pdev->device == 0x0863)554 return VGA_SWITCHEROO_IGD;555 else556 return VGA_SWITCHEROO_DIS;557}558 559static const struct vga_switcheroo_handler gmux_handler_no_ddc = {560 .switchto = gmux_switchto,561 .power_state = gmux_set_power_state,562 .get_client_id = gmux_get_client_id,563};564 565static const struct vga_switcheroo_handler gmux_handler_ddc = {566 .switchto = gmux_switchto,567 .switch_ddc = gmux_switch_ddc,568 .power_state = gmux_set_power_state,569 .get_client_id = gmux_get_client_id,570};571 572static const struct apple_gmux_config apple_gmux_pio = {573 .read8 = &gmux_pio_read8,574 .write8 = &gmux_pio_write8,575 .read32 = &gmux_pio_read32,576 .write32 = &gmux_pio_write32,577 .gmux_handler = &gmux_handler_ddc,578 .handler_flags = VGA_SWITCHEROO_CAN_SWITCH_DDC,579 .resource_type = IORESOURCE_IO,580 .read_version_as_u32 = false,581 .name = "classic"582};583 584static const struct apple_gmux_config apple_gmux_index = {585 .read8 = &gmux_index_read8,586 .write8 = &gmux_index_write8,587 .read32 = &gmux_index_read32,588 .write32 = &gmux_index_write32,589 .gmux_handler = &gmux_handler_no_ddc,590 .handler_flags = VGA_SWITCHEROO_NEEDS_EDP_CONFIG,591 .resource_type = IORESOURCE_IO,592 .read_version_as_u32 = true,593 .name = "indexed"594};595 596static const struct apple_gmux_config apple_gmux_mmio = {597 .read8 = &gmux_mmio_read8,598 .write8 = &gmux_mmio_write8,599 .read32 = &gmux_mmio_read32,600 .write32 = &gmux_mmio_write32,601 .gmux_handler = &gmux_handler_no_ddc,602 .handler_flags = VGA_SWITCHEROO_NEEDS_EDP_CONFIG,603 .resource_type = IORESOURCE_MEM,604 .read_version_as_u32 = true,605 .name = "T2"606};607 608 609/**610 * DOC: Interrupt611 *612 * gmux is also connected to a GPIO pin of the southbridge and thereby is able613 * to trigger an ACPI GPE. ACPI name GMGP holds this GPIO pin's number. On the614 * MBP5 2008/09 it's GPIO pin 22 of the Nvidia MCP79, on following generations615 * it's GPIO pin 6 of the Intel PCH, on MMIO gmux's it's pin 21.616 *617 * The GPE merely signals that an interrupt occurred, the actual type of event618 * is identified by reading a gmux register.619 *620 * In addition to the GMGP name, gmux's ACPI device also has two methods GMSP621 * and GMLV. GMLV likely means "GMUX Level", and reads the value of the GPIO,622 * while GMSP likely means "GMUX Set Polarity", and seems to write to the GPIO's623 * value. On newer Macbooks (This was introduced with or sometime before the624 * MacBookPro14,3), the ACPI GPE method differentiates between the OS type: On625 * Darwin, only a notification is signaled, whereas on other OSes, the GPIO's626 * value is read and then inverted.627 *628 * Because Linux masquerades as Darwin, it ends up in the notification-only code629 * path. On MMIO gmux's, this seems to lead to us being unable to clear interrupts,630 * unless we call GMSP(0). Without this, there is a flood of status=0 interrupts631 * that can't be cleared. This issue seems to be unique to MMIO gmux's.632 */633 634static inline void gmux_disable_interrupts(struct apple_gmux_data *gmux_data)635{636 gmux_write8(gmux_data, GMUX_PORT_INTERRUPT_ENABLE,637 GMUX_INTERRUPT_DISABLE);638}639 640static inline void gmux_enable_interrupts(struct apple_gmux_data *gmux_data)641{642 gmux_write8(gmux_data, GMUX_PORT_INTERRUPT_ENABLE,643 GMUX_INTERRUPT_ENABLE);644}645 646static inline u8 gmux_interrupt_get_status(struct apple_gmux_data *gmux_data)647{648 return gmux_read8(gmux_data, GMUX_PORT_INTERRUPT_STATUS);649}650 651static void gmux_clear_interrupts(struct apple_gmux_data *gmux_data)652{653 u8 status;654 655 /* to clear interrupts write back current status */656 status = gmux_interrupt_get_status(gmux_data);657 gmux_write8(gmux_data, GMUX_PORT_INTERRUPT_STATUS, status);658 /* Prevent flood of status=0 interrupts */659 if (gmux_data->config == &apple_gmux_mmio)660 acpi_execute_simple_method(gmux_data->dhandle, "GMSP", 0);661}662 663static void gmux_notify_handler(acpi_handle device, u32 value, void *context)664{665 u8 status;666 struct pnp_dev *pnp = (struct pnp_dev *)context;667 struct apple_gmux_data *gmux_data = pnp_get_drvdata(pnp);668 669 status = gmux_interrupt_get_status(gmux_data);670 gmux_disable_interrupts(gmux_data);671 pr_debug("Notify handler called: status %d\n", status);672 673 gmux_clear_interrupts(gmux_data);674 gmux_enable_interrupts(gmux_data);675 676 if (status & GMUX_INTERRUPT_STATUS_POWER)677 complete(&gmux_data->powerchange_done);678}679 680/**681 * DOC: Debugfs Interface682 *683 * gmux ports can be accessed from userspace as a debugfs interface. For example:684 *685 * # echo 4 > /sys/kernel/debug/apple_gmux/selected_port686 * # cat /sys/kernel/debug/apple_gmux/selected_port_data | xxd -p687 * 00000005688 *689 * Reads 4 bytes from port 4 (GMUX_PORT_VERSION_MAJOR).690 *691 * 1 and 4 byte writes are also allowed.692 */693 694static ssize_t gmux_selected_port_data_write(struct file *file,695 const char __user *userbuf, size_t count, loff_t *ppos)696{697 struct apple_gmux_data *gmux_data = file->private_data;698 699 if (*ppos)700 return -EINVAL;701 702 if (count == 1) {703 u8 data;704 705 if (copy_from_user(&data, userbuf, 1))706 return -EFAULT;707 708 gmux_write8(gmux_data, gmux_data->selected_port, data);709 } else if (count == 4) {710 u32 data;711 712 if (copy_from_user(&data, userbuf, 4))713 return -EFAULT;714 715 gmux_write32(gmux_data, gmux_data->selected_port, data);716 } else717 return -EINVAL;718 719 return count;720}721 722static ssize_t gmux_selected_port_data_read(struct file *file,723 char __user *userbuf, size_t count, loff_t *ppos)724{725 struct apple_gmux_data *gmux_data = file->private_data;726 u32 data;727 728 data = gmux_read32(gmux_data, gmux_data->selected_port);729 730 return simple_read_from_buffer(userbuf, count, ppos, &data, sizeof(data));731}732 733static const struct file_operations gmux_port_data_ops = {734 .open = simple_open,735 .write = gmux_selected_port_data_write,736 .read = gmux_selected_port_data_read737};738 739static void gmux_init_debugfs(struct apple_gmux_data *gmux_data)740{741 gmux_data->debug_dentry = debugfs_create_dir(KBUILD_MODNAME, NULL);742 743 debugfs_create_u8("selected_port", 0644, gmux_data->debug_dentry,744 &gmux_data->selected_port);745 debugfs_create_file("selected_port_data", 0644, gmux_data->debug_dentry,746 gmux_data, &gmux_port_data_ops);747}748 749static void gmux_fini_debugfs(struct apple_gmux_data *gmux_data)750{751 debugfs_remove_recursive(gmux_data->debug_dentry);752}753 754static int gmux_suspend(struct device *dev)755{756 struct pnp_dev *pnp = to_pnp_dev(dev);757 struct apple_gmux_data *gmux_data = pnp_get_drvdata(pnp);758 759 gmux_disable_interrupts(gmux_data);760 return 0;761}762 763static int gmux_resume(struct device *dev)764{765 struct pnp_dev *pnp = to_pnp_dev(dev);766 struct apple_gmux_data *gmux_data = pnp_get_drvdata(pnp);767 768 gmux_enable_interrupts(gmux_data);769 gmux_write_switch_state(gmux_data);770 if (gmux_data->power_state == VGA_SWITCHEROO_OFF)771 gmux_set_discrete_state(gmux_data, gmux_data->power_state);772 return 0;773}774 775static int is_thunderbolt(struct device *dev, void *data)776{777 return to_pci_dev(dev)->is_thunderbolt;778}779 780static int gmux_probe(struct pnp_dev *pnp, const struct pnp_device_id *id)781{782 struct apple_gmux_data *gmux_data;783 struct resource *res;784 struct backlight_properties props;785 struct backlight_device *bdev = NULL;786 u8 ver_major, ver_minor, ver_release;787 bool register_bdev = true;788 int ret = -ENXIO;789 acpi_status status;790 unsigned long long gpe;791 enum apple_gmux_type type;792 u32 version;793 794 if (apple_gmux_data)795 return -EBUSY;796 797 if (!apple_gmux_detect(pnp, &type)) {798 pr_info("gmux device not present\n");799 return -ENODEV;800 }801 802 gmux_data = kzalloc(sizeof(*gmux_data), GFP_KERNEL);803 if (!gmux_data)804 return -ENOMEM;805 pnp_set_drvdata(pnp, gmux_data);806 807 switch (type) {808 case APPLE_GMUX_TYPE_MMIO:809 gmux_data->config = &apple_gmux_mmio;810 mutex_init(&gmux_data->index_lock);811 812 res = pnp_get_resource(pnp, IORESOURCE_MEM, 0);813 gmux_data->iostart = res->start;814 /* Although the ACPI table only allocates 8 bytes, we need 16. */815 gmux_data->iolen = 16;816 if (!request_mem_region(gmux_data->iostart, gmux_data->iolen,817 "Apple gmux")) {818 pr_err("gmux I/O already in use\n");819 goto err_free;820 }821 gmux_data->iomem_base = ioremap(gmux_data->iostart, gmux_data->iolen);822 if (!gmux_data->iomem_base) {823 pr_err("couldn't remap gmux mmio region");824 goto err_release;825 }826 goto get_version;827 case APPLE_GMUX_TYPE_INDEXED:828 gmux_data->config = &apple_gmux_index;829 mutex_init(&gmux_data->index_lock);830 break;831 case APPLE_GMUX_TYPE_PIO:832 gmux_data->config = &apple_gmux_pio;833 break;834 }835 836 res = pnp_get_resource(pnp, IORESOURCE_IO, 0);837 gmux_data->iostart = res->start;838 gmux_data->iolen = resource_size(res);839 840 if (!request_region(gmux_data->iostart, gmux_data->iolen,841 "Apple gmux")) {842 pr_err("gmux I/O already in use\n");843 goto err_free;844 }845 846get_version:847 if (gmux_data->config->read_version_as_u32) {848 version = gmux_read32(gmux_data, GMUX_PORT_VERSION_MAJOR);849 ver_major = (version >> 24) & 0xff;850 ver_minor = (version >> 16) & 0xff;851 ver_release = (version >> 8) & 0xff;852 } else {853 ver_major = gmux_read8(gmux_data, GMUX_PORT_VERSION_MAJOR);854 ver_minor = gmux_read8(gmux_data, GMUX_PORT_VERSION_MINOR);855 ver_release = gmux_read8(gmux_data, GMUX_PORT_VERSION_RELEASE);856 }857 pr_info("Found gmux version %d.%d.%d [%s]\n", ver_major, ver_minor,858 ver_release, gmux_data->config->name);859 860 memset(&props, 0, sizeof(props));861 props.type = BACKLIGHT_PLATFORM;862 863 /*864 * All MMIO gmux's have 0xffff as max brightness, but some iMacs incorrectly865 * report 0x03ff, despite the firmware being happy to set 0xffff as the brightness866 * at boot. Force 0xffff for all MMIO gmux's so they all have the correct brightness867 * range.868 */869 if (type == APPLE_GMUX_TYPE_MMIO)870 props.max_brightness = MMIO_GMUX_MAX_BRIGHTNESS;871 else872 props.max_brightness = gmux_read32(gmux_data, GMUX_PORT_MAX_BRIGHTNESS);873 874#if IS_REACHABLE(CONFIG_ACPI_VIDEO)875 register_bdev = acpi_video_get_backlight_type() == acpi_backlight_apple_gmux;876#endif877 if (register_bdev) {878 /*879 * Currently it's assumed that the maximum brightness is less than880 * 2^24 for compatibility with old gmux versions. Cap the max881 * brightness at this value, but print a warning if the hardware882 * reports something higher so that it can be fixed.883 */884 if (WARN_ON(props.max_brightness > GMUX_MAX_BRIGHTNESS))885 props.max_brightness = GMUX_MAX_BRIGHTNESS;886 887 bdev = backlight_device_register("gmux_backlight", &pnp->dev,888 gmux_data, &gmux_bl_ops, &props);889 if (IS_ERR(bdev)) {890 ret = PTR_ERR(bdev);891 goto err_unmap;892 }893 894 gmux_data->bdev = bdev;895 bdev->props.brightness = gmux_get_brightness(bdev);896 backlight_update_status(bdev);897 }898 899 gmux_data->power_state = VGA_SWITCHEROO_ON;900 901 gmux_data->dhandle = ACPI_HANDLE(&pnp->dev);902 if (!gmux_data->dhandle) {903 pr_err("Cannot find acpi handle for pnp device %s\n",904 dev_name(&pnp->dev));905 ret = -ENODEV;906 goto err_notify;907 }908 909 status = acpi_evaluate_integer(gmux_data->dhandle, "GMGP", NULL, &gpe);910 if (ACPI_SUCCESS(status)) {911 gmux_data->gpe = (int)gpe;912 913 status = acpi_install_notify_handler(gmux_data->dhandle,914 ACPI_DEVICE_NOTIFY,915 &gmux_notify_handler, pnp);916 if (ACPI_FAILURE(status)) {917 pr_err("Install notify handler failed: %s\n",918 acpi_format_exception(status));919 ret = -ENODEV;920 goto err_notify;921 }922 923 status = acpi_enable_gpe(NULL, gmux_data->gpe);924 if (ACPI_FAILURE(status)) {925 pr_err("Cannot enable gpe: %s\n",926 acpi_format_exception(status));927 goto err_enable_gpe;928 }929 } else {930 pr_warn("No GPE found for gmux\n");931 gmux_data->gpe = -1;932 }933 934 /*935 * If Thunderbolt is present, the external DP port is not fully936 * switchable. Force its AUX channel to the discrete GPU.937 */938 gmux_data->external_switchable =939 !bus_for_each_dev(&pci_bus_type, NULL, NULL, is_thunderbolt);940 if (!gmux_data->external_switchable)941 gmux_write8(gmux_data, GMUX_PORT_SWITCH_EXTERNAL, 3);942 943 apple_gmux_data = gmux_data;944 init_completion(&gmux_data->powerchange_done);945 gmux_enable_interrupts(gmux_data);946 gmux_read_switch_state(gmux_data);947 948 /*949 * Retina MacBook Pros cannot switch the panel's AUX separately950 * and need eDP pre-calibration. They are distinguishable from951 * pre-retinas by having an "indexed" or "T2" gmux.952 *953 * Pre-retina MacBook Pros can switch the panel's DDC separately.954 */955 ret = vga_switcheroo_register_handler(gmux_data->config->gmux_handler,956 gmux_data->config->handler_flags);957 if (ret) {958 pr_err("Failed to register vga_switcheroo handler\n");959 goto err_register_handler;960 }961 962 gmux_init_debugfs(gmux_data);963 return 0;964 965err_register_handler:966 gmux_disable_interrupts(gmux_data);967 apple_gmux_data = NULL;968 if (gmux_data->gpe >= 0)969 acpi_disable_gpe(NULL, gmux_data->gpe);970err_enable_gpe:971 if (gmux_data->gpe >= 0)972 acpi_remove_notify_handler(gmux_data->dhandle,973 ACPI_DEVICE_NOTIFY,974 &gmux_notify_handler);975err_notify:976 backlight_device_unregister(bdev);977err_unmap:978 if (gmux_data->iomem_base)979 iounmap(gmux_data->iomem_base);980err_release:981 if (gmux_data->config->resource_type == IORESOURCE_MEM)982 release_mem_region(gmux_data->iostart, gmux_data->iolen);983 else984 release_region(gmux_data->iostart, gmux_data->iolen);985err_free:986 kfree(gmux_data);987 return ret;988}989 990static void gmux_remove(struct pnp_dev *pnp)991{992 struct apple_gmux_data *gmux_data = pnp_get_drvdata(pnp);993 994 gmux_fini_debugfs(gmux_data);995 vga_switcheroo_unregister_handler();996 gmux_disable_interrupts(gmux_data);997 if (gmux_data->gpe >= 0) {998 acpi_disable_gpe(NULL, gmux_data->gpe);999 acpi_remove_notify_handler(gmux_data->dhandle,1000 ACPI_DEVICE_NOTIFY,1001 &gmux_notify_handler);1002 }1003 1004 backlight_device_unregister(gmux_data->bdev);1005 1006 if (gmux_data->iomem_base) {1007 iounmap(gmux_data->iomem_base);1008 release_mem_region(gmux_data->iostart, gmux_data->iolen);1009 } else1010 release_region(gmux_data->iostart, gmux_data->iolen);1011 apple_gmux_data = NULL;1012 kfree(gmux_data);1013}1014 1015static const struct pnp_device_id gmux_device_ids[] = {1016 {GMUX_ACPI_HID, 0},1017 {"", 0}1018};1019 1020static const struct dev_pm_ops gmux_dev_pm_ops = {1021 .suspend = gmux_suspend,1022 .resume = gmux_resume,1023};1024 1025static struct pnp_driver gmux_pnp_driver = {1026 .name = "apple-gmux",1027 .probe = gmux_probe,1028 .remove = gmux_remove,1029 .id_table = gmux_device_ids,1030 .driver = {1031 .pm = &gmux_dev_pm_ops,1032 },1033};1034 1035module_pnp_driver(gmux_pnp_driver);1036MODULE_AUTHOR("Seth Forshee <seth.forshee@canonical.com>");1037MODULE_DESCRIPTION("Apple Gmux Driver");1038MODULE_LICENSE("GPL");1039MODULE_DEVICE_TABLE(pnp, gmux_device_ids);1040