projects / linux-2.6-block.git / blame
? search:
summary | shortlog | log | commit | commitdiff | tree
blob | blame (incremental) | history | HEAD
Linux 6.12-rc1
[linux-2.6-block.git] / drivers / platform / x86 / apple-gmux.c
CommitLineData
d2912cb1 1// SPDX-License-Identifier: GPL-2.0-only
917ee75a
SF		 2/*
3 * Gmux driver for Apple laptops
4 *
5 * Copyright (C) Canonical Ltd. <seth.forshee@canonical.com>
76b487dd 6 * Copyright (C) 2010-2012 Andreas Heider <andreas@meetr.de>
3d7b75fd 7 * Copyright (C) 2015 Lukas Wunner <lukas@wunner.de>
96ec2d98 8 * Copyright (C) 2023 Orlando Chamberlain <orlandoch.dev@gmail.com>
917ee75a
SF		 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>
2413306c 19#include <linux/apple-gmux.h>
917ee75a 20#include <linux/slab.h>
96ff7056 21#include <linux/delay.h>
76b487dd
AH		 22#include <linux/pci.h>
23#include <linux/vga_switcheroo.h>
f863fac1 24#include <linux/debugfs.h>
d2e68321 25#include <acpi/video.h>
917ee75a
SF		 26#include <asm/io.h>
27
3d7b75fd
LW		 28/**
29 * DOC: Overview
30 *
3d7b75fd 31 * gmux is a microcontroller built into the MacBook Pro to support dual GPUs:
0c18184d
OC		 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.
3d7b75fd
LW		 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
0c18184d
OC		 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_``.
305964b7
LW		 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
0c18184d
OC		 53 * .. _NXP PCAL6524:
54 * https://www.nxp.com/docs/en/data-sheet/PCAL6524.pdf
3d7b75fd
LW		 55 */
56
96ec2d98
OC		 57struct apple_gmux_config;
58
917ee75a 59struct apple_gmux_data {
fb131c47 60 u8 __iomem *iomem_base;
917ee75a
SF		 61 unsigned long iostart;
62 unsigned long iolen;
96ec2d98 63 const struct apple_gmux_config *config;
96ff7056 64 struct mutex index_lock;
917ee75a
SF		 65
66 struct backlight_device *bdev;
76b487dd
AH		 67
68 /* switcheroo data */
69 acpi_handle dhandle;
70 int gpe;
b121b051 71 bool external_switchable;
3e46304e
LW		 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;
76b487dd
AH		 75 enum vga_switcheroo_state power_state;
76 struct completion powerchange_done;
f863fac1
OC		 77
78 /* debugfs data */
79 u8 selected_port;
80 struct dentry *debug_dentry;
917ee75a
SF		 81};
82
76b487dd
AH		 83static struct apple_gmux_data *apple_gmux_data;
84
96ec2d98
OC		 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
917ee75a
SF		 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
0e51cb42
OC		 108# define MMIO_GMUX_MAX_BRIGHTNESS 0xffff
109
96ff7056 110static u8 gmux_pio_read8(struct apple_gmux_data *gmux_data, int port)
917ee75a
SF		 111{
112 return inb(gmux_data->iostart + port);
113}
114
96ff7056 115static void gmux_pio_write8(struct apple_gmux_data *gmux_data, int port,
917ee75a
SF		 116 u8 val)
117{
118 outb(val, gmux_data->iostart + port);
119}
120
96ff7056 121static u32 gmux_pio_read32(struct apple_gmux_data *gmux_data, int port)
917ee75a
SF		 122{
123 return inl(gmux_data->iostart + port);
124}
125
96ff7056
MG		 126static void gmux_pio_write32(struct apple_gmux_data *gmux_data, int port,
127 u32 val)
7e30ed6b
MG		 128{
129 int i;
130 u8 tmpval;
131
132 for (i = 0; i < 4; i++) {
133 tmpval = (val >> (i * 8)) & 0xff;
e6d9d3d5 134 outb(tmpval, gmux_data->iostart + port + i);
7e30ed6b
MG		 135 }
136}
137
96ff7056
MG		 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);
96ff7056 175 gmux_index_wait_ready(gmux_data);
c5a50529
BF		 176 outb((port & 0xff), gmux_data->iostart + GMUX_PORT_READ);
177 gmux_index_wait_complete(gmux_data);
96ff7056
MG		 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);
96ff7056 200 gmux_index_wait_ready(gmux_data);
c5a50529
BF		 201 outb((port & 0xff), gmux_data->iostart + GMUX_PORT_READ);
202 gmux_index_wait_complete(gmux_data);
96ff7056
MG		 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
0c18184d
OC		 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);
669f1f48 283 val = ioread32be(gmux_data->iomem_base);
0c18184d
OC		 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);
669f1f48 293 iowrite32be(val, gmux_data->iomem_base);
0c18184d
OC		 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
96ff7056
MG		 301static u8 gmux_read8(struct apple_gmux_data *gmux_data, int port)
302{
96ec2d98 303 return gmux_data->config->read8(gmux_data, port);
96ff7056
MG		 304}
305
306static void gmux_write8(struct apple_gmux_data *gmux_data, int port, u8 val)
307{
96ec2d98 308 return gmux_data->config->write8(gmux_data, port, val);
96ff7056
MG		 309}
310
311static u32 gmux_read32(struct apple_gmux_data *gmux_data, int port)
312{
96ec2d98 313 return gmux_data->config->read32(gmux_data, port);
96ff7056
MG		 314}
315
316static void gmux_write32(struct apple_gmux_data *gmux_data, int port,
317 u32 val)
318{
96ec2d98 319 return gmux_data->config->write32(gmux_data, port, val);
96ff7056
MG		 320}
321
3d7b75fd
LW		 322/**
323 * DOC: Backlight control
324 *
3d7b75fd
LW		 325 * On single GPU MacBooks, the PWM signal for the backlight is generated by
326 * the GPU. On dual GPU MacBook Pros by contrast, either GPU may be suspended
327 * to conserve energy. Hence the PWM signal needs to be generated by a separate
328 * backlight driver which is controlled by gmux. The earliest generation
0c18184d
OC		 329 * MBP5 2008/09 uses a `TI LP8543`_ backlight driver. Newer models
330 * use a `TI LP8545`_ or a TI LP8548.
305964b7 331 *
6abe66ec
AK		 332 * .. _TI LP8543: https://www.ti.com/lit/ds/symlink/lp8543.pdf
333 * .. _TI LP8545: https://www.ti.com/lit/ds/symlink/lp8545.pdf
3d7b75fd
LW		 334 */
335
917ee75a
SF		 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);
3096ab5b 346 u32 brightness = backlight_get_brightness(bd);
96960880 347
7e30ed6b 348 gmux_write32(gmux_data, GMUX_PORT_BRIGHTNESS, brightness);
917ee75a
SF		 349
350 return 0;
351}
352
353static const struct backlight_ops gmux_bl_ops = {
96960880 354 .options = BL_CORE_SUSPENDRESUME,
917ee75a
SF		 355 .get_brightness = gmux_get_brightness,
356 .update_status = gmux_update_status,
357};
358
3d7b75fd
LW		 359/**
360 * DOC: Graphics mux
361 *
3d7b75fd
LW		 362 * On pre-retinas, the LVDS outputs of both GPUs feed into gmux which muxes
363 * either of them to the panel. One of the tricks gmux has up its sleeve is
364 * to lengthen the blanking interval of its output during a switch to
365 * synchronize it with the GPU switched to. This allows for a flicker-free
305964b7 366 * switch that is imperceptible by the user (`US 8,687,007 B2`_).
3d7b75fd
LW		 367 *
368 * On retinas, muxing is no longer done by gmux itself, but by a separate
369 * chip which is controlled by gmux. The chip is triple sourced, it is
305964b7 370 * either an `NXP CBTL06142`_, `TI HD3SS212`_ or `Pericom PI3VDP12412`_.
3d7b75fd
LW		 371 * The panel is driven with eDP instead of LVDS since the pixel clock
372 * required for retina resolution exceeds LVDS' limits.
373 *
374 * Pre-retinas are able to switch the panel's DDC pins separately.
305964b7 375 * This is handled by a `TI SN74LV4066A`_ which is controlled by gmux.
3d7b75fd
LW		 376 * The inactive GPU can thus probe the panel's EDID without switching over
377 * the entire panel. Retinas lack this functionality as the chips used for
378 * eDP muxing are incapable of switching the AUX channel separately (see
379 * 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 set
381 * in its DPCD, allowing the inactive GPU to skip the AUX handshake and
382 * 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 unibody
385 * MacBook Pro generations, MBP5 2008/09 and MBP6 2010. This is done by an
305964b7 386 * `NXP CBTL06141`_ which is controlled by gmux. It's the predecessor of the
3d7b75fd
LW		 387 * 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 a
390 * 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 HPD
305964b7 393 * are still switchable by way of an `NXP CBTL03062`_ (on pre-retinas
0c18184d
OC		 394 * MBP8 2011 and MBP9 2012) or two `TI TS3DS10224`_ (on pre-t2 retinas) under
395 * the control of gmux. Since the integrated GPU is missing the main link,
3d7b75fd
LW		 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 an
399 * 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 improve
402 * reliability of hotplug detection by having the integrated GPU poll the
403 * ports while the discrete GPU is asleep, but currently we do not make use
404 * of this feature.
405 *
b121b051
LW		 406 * Our switching policy for the external port is that on those generations
407 * which are able to switch it fully, the port is switched together with the
408 * panel when IGD / DIS commands are issued to vga_switcheroo. It is thus
409 * 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 is
411 * needed.
412 *
413 * On all newer generations, the external port can only be driven by the
414 * discrete GPU. If a display is plugged in while the panel is switched to
415 * the integrated GPU, *both* GPUs will be in use for maximum performance.
416 * To decrease power consumption, the user may manually switch to the
417 * discrete GPU, thereby suspending the integrated GPU.
418 *
3d7b75fd 419 * gmux' initial switch state on bootup is user configurable via the EFI
305964b7 420 * variable ``gpu-power-prefs-fa4ce28d-b62f-4c99-9cc3-6815686e30f9`` (5th byte,
3d7b75fd
LW		 421 * 1 = IGD, 0 = DIS). Based on this setting, the EFI firmware tells gmux to
422 * switch the panel and the external DP connector and allocates a framebuffer
423 * for the selected GPU.
305964b7 424 *
6abe66ec
AK		 425 * .. _US 8,687,007 B2: https://pimg-fpiw.uspto.gov/fdd/07/870/086/0.pdf
426 * .. _NXP CBTL06141: https://www.nxp.com/documents/data_sheet/CBTL06141.pdf
427 * .. _NXP CBTL06142: https://www.nxp.com/documents/data_sheet/CBTL06141.pdf
428 * .. _TI HD3SS212: https://www.ti.com/lit/ds/symlink/hd3ss212.pdf
305964b7 429 * .. _Pericom PI3VDP12412: https://www.pericom.com/assets/Datasheets/PI3VDP12412.pdf
6abe66ec 430 * .. _TI SN74LV4066A: https://www.ti.com/lit/ds/symlink/sn74lv4066a.pdf
305964b7 431 * .. _NXP CBTL03062: http://pdf.datasheetarchive.com/indexerfiles/Datasheets-SW16/DSASW00308511.pdf
6abe66ec 432 * .. _TI TS3DS10224: https://www.ti.com/lit/ds/symlink/ts3ds10224.pdf
3d7b75fd
LW		 433 */
434
3e46304e
LW		 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 else
440 gmux_data->switch_state_ddc = VGA_SWITCHEROO_DIS;
441
90caf1df 442 if (gmux_read8(gmux_data, GMUX_PORT_SWITCH_DISPLAY) & 1)
3e46304e 443 gmux_data->switch_state_display = VGA_SWITCHEROO_DIS;
90caf1df
OC		 444 else
445 gmux_data->switch_state_display = VGA_SWITCHEROO_IGD;
3e46304e
LW		 446
447 if (gmux_read8(gmux_data, GMUX_PORT_SWITCH_EXTERNAL) == 2)
448 gmux_data->switch_state_external = VGA_SWITCHEROO_IGD;
449 else
450 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 else
458 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 else
463 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 else
468 gmux_write8(gmux_data, GMUX_PORT_SWITCH_EXTERNAL, 3);
469}
470
76b487dd
AH		 471static int gmux_switchto(enum vga_switcheroo_client_id id)
472{
3e46304e
LW		 473 apple_gmux_data->switch_state_ddc = id;
474 apple_gmux_data->switch_state_display = id;
b121b051
LW		 475 if (apple_gmux_data->external_switchable)
476 apple_gmux_data->switch_state_external = id;
3e46304e
LW		 477
478 gmux_write_switch_state(apple_gmux_data);
76b487dd
AH		 479
480 return 0;
481}
482
f798d965
LW		 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 else
497 gmux_write8(apple_gmux_data, GMUX_PORT_SWITCH_DDC, 2);
498
499 return old_ddc_owner;
500}
501
3d7b75fd
LW		 502/**
503 * DOC: Power control
504 *
505 * gmux is able to cut power to the discrete GPU. It automatically takes care
506 * of the correct sequence to tear down and bring up the power rails for
507 * core voltage, VRAM and PCIe.
508 */
509
76b487dd
AH		 510static int gmux_set_discrete_state(struct apple_gmux_data *gmux_data,
511 enum vga_switcheroo_state state)
512{
16735d02 513 reinit_completion(&gmux_data->powerchange_done);
76b487dd
AH		 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
19e75205 544static enum vga_switcheroo_client_id gmux_get_client_id(struct pci_dev *pdev)
76b487dd
AH		 545{
546 /*
547 * Early Macbook Pros with switchable graphics use nvidia
548 * 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 else
556 return VGA_SWITCHEROO_DIS;
557}
558
96ec2d98 559static const struct vga_switcheroo_handler gmux_handler_no_ddc = {
76b487dd
AH		 560 .switchto = gmux_switchto,
561 .power_state = gmux_set_power_state,
562 .get_client_id = gmux_get_client_id,
563};
564
96ec2d98 565static const struct vga_switcheroo_handler gmux_handler_ddc = {
f798d965
LW		 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
96ec2d98
OC		 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
0c18184d
OC		 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
3d7b75fd
LW		 609/**
610 * DOC: Interrupt
611 *
612 * gmux is also connected to a GPIO pin of the southbridge and thereby is able
0c18184d
OC		 613 * to trigger an ACPI GPE. ACPI name GMGP holds this GPIO pin's number. On the
614 * MBP5 2008/09 it's GPIO pin 22 of the Nvidia MCP79, on following generations
615 * it's GPIO pin 6 of the Intel PCH, on MMIO gmux's it's pin 21.
616 *
3d7b75fd
LW		 617 * The GPE merely signals that an interrupt occurred, the actual type of event
618 * is identified by reading a gmux register.
0c18184d
OC		 619 *
620 * In addition to the GMGP name, gmux's ACPI device also has two methods GMSP
621 * 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's
623 * value. On newer Macbooks (This was introduced with or sometime before the
624 * MacBookPro14,3), the ACPI GPE method differentiates between the OS type: On
625 * Darwin, only a notification is signaled, whereas on other OSes, the GPIO's
626 * value is read and then inverted.
627 *
628 * Because Linux masquerades as Darwin, it ends up in the notification-only code
629 * 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 interrupts
631 * that can't be cleared. This issue seems to be unique to MMIO gmux's.
3d7b75fd
LW		 632 */
633
76b487dd
AH		 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);
0c18184d
OC		 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);
76b487dd
AH		 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
f863fac1
OC		 680/**
681 * DOC: Debugfs Interface
682 *
683 * gmux ports can be accessed from userspace as a debugfs interface. For example:
684 *
685 * # echo 4 > /sys/kernel/debug/apple_gmux/selected_port
686 * # cat /sys/kernel/debug/apple_gmux/selected_port_data | xxd -p
687 * 00000005
688 *
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;
f863fac1
OC		 698
699 if (*ppos)
700 return -EINVAL;
701
702 if (count == 1) {
703 u8 data;
704
f0f2903d
DC		 705 if (copy_from_user(&data, userbuf, 1))
706 return -EFAULT;
707
f863fac1
OC		 708 gmux_write8(gmux_data, gmux_data->selected_port, data);
709 } else if (count == 4) {
710 u32 data;
711
f0f2903d
DC		 712 if (copy_from_user(&data, userbuf, 4))
713 return -EFAULT;
714
f863fac1
OC		 715 gmux_write32(gmux_data, gmux_data->selected_port, data);
716 } else
717 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_read
737};
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
8aa6c216 754static int gmux_suspend(struct device *dev)
76b487dd 755{
8aa6c216 756 struct pnp_dev *pnp = to_pnp_dev(dev);
76b487dd 757 struct apple_gmux_data *gmux_data = pnp_get_drvdata(pnp);
8aa6c216 758
76b487dd
AH		 759 gmux_disable_interrupts(gmux_data);
760 return 0;
761}
762
8aa6c216 763static int gmux_resume(struct device *dev)
76b487dd 764{
8aa6c216 765 struct pnp_dev *pnp = to_pnp_dev(dev);
76b487dd 766 struct apple_gmux_data *gmux_data = pnp_get_drvdata(pnp);
8aa6c216 767
76b487dd 768 gmux_enable_interrupts(gmux_data);
3e46304e 769 gmux_write_switch_state(gmux_data);
76b487dd
AH		 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
b121b051
LW		 775static int is_thunderbolt(struct device *dev, void *data)
776{
777 return to_pci_dev(dev)->is_thunderbolt;
778}
779
b859f159 780static int gmux_probe(struct pnp_dev *pnp, const struct pnp_device_id *id)
917ee75a
SF		 781{
782 struct apple_gmux_data *gmux_data;
783 struct resource *res;
784 struct backlight_properties props;
d2e68321 785 struct backlight_device *bdev = NULL;
917ee75a 786 u8 ver_major, ver_minor, ver_release;
d2e68321 787 bool register_bdev = true;
917ee75a 788 int ret = -ENXIO;
76b487dd
AH		 789 acpi_status status;
790 unsigned long long gpe;
96ec2d98 791 enum apple_gmux_type type;
d143908f 792 u32 version;
76b487dd
AH		 793
794 if (apple_gmux_data)
795 return -EBUSY;
917ee75a 796
96ec2d98 797 if (!apple_gmux_detect(pnp, &type)) {
d143908f
HG		 798 pr_info("gmux device not present\n");
799 return -ENODEV;
800 }
801
917ee75a
SF		 802 gmux_data = kzalloc(sizeof(*gmux_data), GFP_KERNEL);
803 if (!gmux_data)
804 return -ENOMEM;
805 pnp_set_drvdata(pnp, gmux_data);
806
96ec2d98 807 switch (type) {
0c18184d
OC		 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;
96ec2d98
OC		 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
917ee75a 836 res = pnp_get_resource(pnp, IORESOURCE_IO, 0);
917ee75a 837 gmux_data->iostart = res->start;
eb66fb03 838 gmux_data->iolen = resource_size(res);
917ee75a 839
917ee75a
SF		 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
0c18184d 846get_version:
96ec2d98 847 if (gmux_data->config->read_version_as_u32) {
d143908f
HG		 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);
917ee75a 856 }
07f377da 857 pr_info("Found gmux version %d.%d.%d [%s]\n", ver_major, ver_minor,
96ec2d98 858 ver_release, gmux_data->config->name);
917ee75a 859
917ee75a
SF		 860 memset(&props, 0, sizeof(props));
861 props.type = BACKLIGHT_PLATFORM;
0e51cb42
OC		 862
863 /*
864 * All MMIO gmux's have 0xffff as max brightness, but some iMacs incorrectly
865 * report 0x03ff, despite the firmware being happy to set 0xffff as the brightness
866 * at boot. Force 0xffff for all MMIO gmux's so they all have the correct brightness
867 * range.
868 */
869 if (type == APPLE_GMUX_TYPE_MMIO)
870 props.max_brightness = MMIO_GMUX_MAX_BRIGHTNESS;
871 else
872 props.max_brightness = gmux_read32(gmux_data, GMUX_PORT_MAX_BRIGHTNESS);
917ee75a 873
d2e68321
HG		 874#if IS_REACHABLE(CONFIG_ACPI_VIDEO)
875 register_bdev = acpi_video_get_backlight_type() == acpi_backlight_apple_gmux;
876#endif
877 if (register_bdev) {
878 /*
879 * Currently it's assumed that the maximum brightness is less than
880 * 2^24 for compatibility with old gmux versions. Cap the max
881 * brightness at this value, but print a warning if the hardware
882 * 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 }
917ee75a 893
d2e68321
HG		 894 gmux_data->bdev = bdev;
895 bdev->props.brightness = gmux_get_brightness(bdev);
896 backlight_update_status(bdev);
d2e68321 897 }
917ee75a 898
76b487dd
AH		 899 gmux_data->power_state = VGA_SWITCHEROO_ON;
900
3a83f992 901 gmux_data->dhandle = ACPI_HANDLE(&pnp->dev);
76b487dd
AH		 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
b121b051
LW		 934 /*
935 * If Thunderbolt is present, the external DP port is not fully
936 * 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
c1e1655b
MG		 943 apple_gmux_data = gmux_data;
944 init_completion(&gmux_data->powerchange_done);
945 gmux_enable_interrupts(gmux_data);
3e46304e 946 gmux_read_switch_state(gmux_data);
c1e1655b 947
f798d965
LW		 948 /*
949 * Retina MacBook Pros cannot switch the panel's AUX separately
950 * and need eDP pre-calibration. They are distinguishable from
0c18184d 951 * pre-retinas by having an "indexed" or "T2" gmux.
f798d965
LW		 952 *
953 * Pre-retina MacBook Pros can switch the panel's DDC separately.
954 */
96ec2d98
OC		 955 ret = vga_switcheroo_register_handler(gmux_data->config->gmux_handler,
956 gmux_data->config->handler_flags);
f798d965
LW		 957 if (ret) {
958 pr_err("Failed to register vga_switcheroo handler\n");
76b487dd
AH		 959 goto err_register_handler;
960 }
961
f863fac1 962 gmux_init_debugfs(gmux_data);
917ee75a
SF		 963 return 0;
964
76b487dd 965err_register_handler:
c1e1655b
MG		 966 gmux_disable_interrupts(gmux_data);
967 apple_gmux_data = NULL;
76b487dd
AH		 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);
0c18184d
OC		 977err_unmap:
978 if (gmux_data->iomem_base)
979 iounmap(gmux_data->iomem_base);
917ee75a 980err_release:
0c18184d
OC		 981 if (gmux_data->config->resource_type == IORESOURCE_MEM)
982 release_mem_region(gmux_data->iostart, gmux_data->iolen);
983 else
984 release_region(gmux_data->iostart, gmux_data->iolen);
917ee75a
SF		 985err_free:
986 kfree(gmux_data);
987 return ret;
988}
989
b859f159 990static void gmux_remove(struct pnp_dev *pnp)
917ee75a
SF		 991{
992 struct apple_gmux_data *gmux_data = pnp_get_drvdata(pnp);
993
f863fac1 994 gmux_fini_debugfs(gmux_data);
76b487dd
AH		 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
917ee75a 1004 backlight_device_unregister(gmux_data->bdev);
76b487dd 1005
0c18184d
OC		 1006 if (gmux_data->iomem_base) {
1007 iounmap(gmux_data->iomem_base);
1008 release_mem_region(gmux_data->iostart, gmux_data->iolen);
1009 } else
1010 release_region(gmux_data->iostart, gmux_data->iolen);
76b487dd 1011 apple_gmux_data = NULL;
917ee75a 1012 kfree(gmux_data);
917ee75a
SF		 1013}
1014
1015static const struct pnp_device_id gmux_device_ids[] = {
2413306c 1016 {GMUX_ACPI_HID, 0},
917ee75a
SF		 1017 {"", 0}
1018};
1019
8aa6c216
SK		 1020static const struct dev_pm_ops gmux_dev_pm_ops = {
1021 .suspend = gmux_suspend,
1022 .resume = gmux_resume,
1023};
1024
917ee75a
SF		 1025static struct pnp_driver gmux_pnp_driver = {
1026 .name = "apple-gmux",
1027 .probe = gmux_probe,
b859f159 1028 .remove = gmux_remove,
917ee75a 1029 .id_table = gmux_device_ids,
8aa6c216
SK		 1030 .driver = {
1031 .pm = &gmux_dev_pm_ops,
1032 },
917ee75a
SF		 1033};
1034
99f74f12 1035module_pnp_driver(gmux_pnp_driver);
917ee75a
SF		 1036MODULE_AUTHOR("Seth Forshee <seth.forshee@canonical.com>");
1037MODULE_DESCRIPTION("Apple Gmux Driver");
1038MODULE_LICENSE("GPL");
1039MODULE_DEVICE_TABLE(pnp, gmux_device_ids);
Linux 6.x block layer and io_uring tree(s)