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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 */
9
10#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
11
12#include <linux/module.h>
13#include <linux/kernel.h>
14#include <linux/init.h>
15#include <linux/backlight.h>
16#include <linux/acpi.h>
17#include <linux/pnp.h>
18#include <linux/apple_bl.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 <asm/io.h>
25
26/**
27 * DOC: Overview
28 *
29 * gmux is a microcontroller built into the MacBook Pro to support dual GPUs:
30 * A `Lattice XP2`_ on pre-retinas, a `Renesas R4F2113`_ on retinas.
31 *
32 * (The MacPro6,1 2013 also has a gmux, however it is unclear why since it has
33 * dual GPUs but no built-in display.)
34 *
35 * gmux is connected to the LPC bus of the southbridge. Its I/O ports are
36 * accessed differently depending on the microcontroller: Driver functions
37 * to access a pre-retina gmux are infixed ``_pio_``, those for a retina gmux
38 * are infixed ``_index_``.
39 *
40 * .. _Lattice XP2:
41 * http://www.latticesemi.com/en/Products/FPGAandCPLD/LatticeXP2.aspx
42 * .. _Renesas R4F2113:
43 * http://www.renesas.com/products/mpumcu/h8s/h8s2100/h8s2113/index.jsp
44 */
45
46struct apple_gmux_data {
47 unsigned long iostart;
48 unsigned long iolen;
49 bool indexed;
50 struct mutex index_lock;
51
52 struct backlight_device *bdev;
53
54 /* switcheroo data */
55 acpi_handle dhandle;
56 int gpe;
57 bool external_switchable;
58 enum vga_switcheroo_client_id switch_state_display;
59 enum vga_switcheroo_client_id switch_state_ddc;
60 enum vga_switcheroo_client_id switch_state_external;
61 enum vga_switcheroo_state power_state;
62 struct completion powerchange_done;
63};
64
65static struct apple_gmux_data *apple_gmux_data;
66
67#define GMUX_INTERRUPT_ENABLE 0xff
68#define GMUX_INTERRUPT_DISABLE 0x00
69
70#define GMUX_INTERRUPT_STATUS_ACTIVE 0
71#define GMUX_INTERRUPT_STATUS_DISPLAY (1 << 0)
72#define GMUX_INTERRUPT_STATUS_POWER (1 << 2)
73#define GMUX_INTERRUPT_STATUS_HOTPLUG (1 << 3)
74
75#define GMUX_BRIGHTNESS_MASK 0x00ffffff
76#define GMUX_MAX_BRIGHTNESS GMUX_BRIGHTNESS_MASK
77
78static u8 gmux_pio_read8(struct apple_gmux_data *gmux_data, int port)
79{
80 return inb(gmux_data->iostart + port);
81}
82
83static void gmux_pio_write8(struct apple_gmux_data *gmux_data, int port,
84 u8 val)
85{
86 outb(val, gmux_data->iostart + port);
87}
88
89static u32 gmux_pio_read32(struct apple_gmux_data *gmux_data, int port)
90{
91 return inl(gmux_data->iostart + port);
92}
93
94static void gmux_pio_write32(struct apple_gmux_data *gmux_data, int port,
95 u32 val)
96{
97 int i;
98 u8 tmpval;
99
100 for (i = 0; i < 4; i++) {
101 tmpval = (val >> (i * 8)) & 0xff;
102 outb(tmpval, gmux_data->iostart + port + i);
103 }
104}
105
106static int gmux_index_wait_ready(struct apple_gmux_data *gmux_data)
107{
108 int i = 200;
109 u8 gwr = inb(gmux_data->iostart + GMUX_PORT_WRITE);
110
111 while (i && (gwr & 0x01)) {
112 inb(gmux_data->iostart + GMUX_PORT_READ);
113 gwr = inb(gmux_data->iostart + GMUX_PORT_WRITE);
114 udelay(100);
115 i--;
116 }
117
118 return !!i;
119}
120
121static int gmux_index_wait_complete(struct apple_gmux_data *gmux_data)
122{
123 int i = 200;
124 u8 gwr = inb(gmux_data->iostart + GMUX_PORT_WRITE);
125
126 while (i && !(gwr & 0x01)) {
127 gwr = inb(gmux_data->iostart + GMUX_PORT_WRITE);
128 udelay(100);
129 i--;
130 }
131
132 if (gwr & 0x01)
133 inb(gmux_data->iostart + GMUX_PORT_READ);
134
135 return !!i;
136}
137
138static u8 gmux_index_read8(struct apple_gmux_data *gmux_data, int port)
139{
140 u8 val;
141
142 mutex_lock(&gmux_data->index_lock);
143 gmux_index_wait_ready(gmux_data);
144 outb((port & 0xff), gmux_data->iostart + GMUX_PORT_READ);
145 gmux_index_wait_complete(gmux_data);
146 val = inb(gmux_data->iostart + GMUX_PORT_VALUE);
147 mutex_unlock(&gmux_data->index_lock);
148
149 return val;
150}
151
152static void gmux_index_write8(struct apple_gmux_data *gmux_data, int port,
153 u8 val)
154{
155 mutex_lock(&gmux_data->index_lock);
156 outb(val, gmux_data->iostart + GMUX_PORT_VALUE);
157 gmux_index_wait_ready(gmux_data);
158 outb(port & 0xff, gmux_data->iostart + GMUX_PORT_WRITE);
159 gmux_index_wait_complete(gmux_data);
160 mutex_unlock(&gmux_data->index_lock);
161}
162
163static u32 gmux_index_read32(struct apple_gmux_data *gmux_data, int port)
164{
165 u32 val;
166
167 mutex_lock(&gmux_data->index_lock);
168 gmux_index_wait_ready(gmux_data);
169 outb((port & 0xff), gmux_data->iostart + GMUX_PORT_READ);
170 gmux_index_wait_complete(gmux_data);
171 val = inl(gmux_data->iostart + GMUX_PORT_VALUE);
172 mutex_unlock(&gmux_data->index_lock);
173
174 return val;
175}
176
177static void gmux_index_write32(struct apple_gmux_data *gmux_data, int port,
178 u32 val)
179{
180 int i;
181 u8 tmpval;
182
183 mutex_lock(&gmux_data->index_lock);
184
185 for (i = 0; i < 4; i++) {
186 tmpval = (val >> (i * 8)) & 0xff;
187 outb(tmpval, gmux_data->iostart + GMUX_PORT_VALUE + i);
188 }
189
190 gmux_index_wait_ready(gmux_data);
191 outb(port & 0xff, gmux_data->iostart + GMUX_PORT_WRITE);
192 gmux_index_wait_complete(gmux_data);
193 mutex_unlock(&gmux_data->index_lock);
194}
195
196static u8 gmux_read8(struct apple_gmux_data *gmux_data, int port)
197{
198 if (gmux_data->indexed)
199 return gmux_index_read8(gmux_data, port);
200 else
201 return gmux_pio_read8(gmux_data, port);
202}
203
204static void gmux_write8(struct apple_gmux_data *gmux_data, int port, u8 val)
205{
206 if (gmux_data->indexed)
207 gmux_index_write8(gmux_data, port, val);
208 else
209 gmux_pio_write8(gmux_data, port, val);
210}
211
212static u32 gmux_read32(struct apple_gmux_data *gmux_data, int port)
213{
214 if (gmux_data->indexed)
215 return gmux_index_read32(gmux_data, port);
216 else
217 return gmux_pio_read32(gmux_data, port);
218}
219
220static void gmux_write32(struct apple_gmux_data *gmux_data, int port,
221 u32 val)
222{
223 if (gmux_data->indexed)
224 gmux_index_write32(gmux_data, port, val);
225 else
226 gmux_pio_write32(gmux_data, port, val);
227}
228
229/**
230 * DOC: Backlight control
231 *
232 * On single GPU MacBooks, the PWM signal for the backlight is generated by
233 * the GPU. On dual GPU MacBook Pros by contrast, either GPU may be suspended
234 * to conserve energy. Hence the PWM signal needs to be generated by a separate
235 * backlight driver which is controlled by gmux. The earliest generation
236 * MBP5 2008/09 uses a `TI LP8543`_ backlight driver. All newer models
237 * use a `TI LP8545`_.
238 *
239 * .. _TI LP8543: https://www.ti.com/lit/ds/symlink/lp8543.pdf
240 * .. _TI LP8545: https://www.ti.com/lit/ds/symlink/lp8545.pdf
241 */
242
243static int gmux_get_brightness(struct backlight_device *bd)
244{
245 struct apple_gmux_data *gmux_data = bl_get_data(bd);
246 return gmux_read32(gmux_data, GMUX_PORT_BRIGHTNESS) &
247 GMUX_BRIGHTNESS_MASK;
248}
249
250static int gmux_update_status(struct backlight_device *bd)
251{
252 struct apple_gmux_data *gmux_data = bl_get_data(bd);
253 u32 brightness = backlight_get_brightness(bd);
254
255 gmux_write32(gmux_data, GMUX_PORT_BRIGHTNESS, brightness);
256
257 return 0;
258}
259
260static const struct backlight_ops gmux_bl_ops = {
261 .options = BL_CORE_SUSPENDRESUME,
262 .get_brightness = gmux_get_brightness,
263 .update_status = gmux_update_status,
264};
265
266/**
267 * DOC: Graphics mux
268 *
269 * On pre-retinas, the LVDS outputs of both GPUs feed into gmux which muxes
270 * either of them to the panel. One of the tricks gmux has up its sleeve is
271 * to lengthen the blanking interval of its output during a switch to
272 * synchronize it with the GPU switched to. This allows for a flicker-free
273 * switch that is imperceptible by the user (`US 8,687,007 B2`_).
274 *
275 * On retinas, muxing is no longer done by gmux itself, but by a separate
276 * chip which is controlled by gmux. The chip is triple sourced, it is
277 * either an `NXP CBTL06142`_, `TI HD3SS212`_ or `Pericom PI3VDP12412`_.
278 * The panel is driven with eDP instead of LVDS since the pixel clock
279 * required for retina resolution exceeds LVDS' limits.
280 *
281 * Pre-retinas are able to switch the panel's DDC pins separately.
282 * This is handled by a `TI SN74LV4066A`_ which is controlled by gmux.
283 * The inactive GPU can thus probe the panel's EDID without switching over
284 * the entire panel. Retinas lack this functionality as the chips used for
285 * eDP muxing are incapable of switching the AUX channel separately (see
286 * the linked data sheets, Pericom would be capable but this is unused).
287 * However the retina panel has the NO_AUX_HANDSHAKE_LINK_TRAINING bit set
288 * in its DPCD, allowing the inactive GPU to skip the AUX handshake and
289 * set up the output with link parameters pre-calibrated by the active GPU.
290 *
291 * The external DP port is only fully switchable on the first two unibody
292 * MacBook Pro generations, MBP5 2008/09 and MBP6 2010. This is done by an
293 * `NXP CBTL06141`_ which is controlled by gmux. It's the predecessor of the
294 * eDP mux on retinas, the difference being support for 2.7 versus 5.4 Gbit/s.
295 *
296 * The following MacBook Pro generations replaced the external DP port with a
297 * combined DP/Thunderbolt port and lost the ability to switch it between GPUs,
298 * connecting it either to the discrete GPU or the Thunderbolt controller.
299 * Oddly enough, while the full port is no longer switchable, AUX and HPD
300 * are still switchable by way of an `NXP CBTL03062`_ (on pre-retinas
301 * MBP8 2011 and MBP9 2012) or two `TI TS3DS10224`_ (on retinas) under the
302 * control of gmux. Since the integrated GPU is missing the main link,
303 * external displays appear to it as phantoms which fail to link-train.
304 *
305 * gmux receives the HPD signal of all display connectors and sends an
306 * interrupt on hotplug. On generations which cannot switch external ports,
307 * the discrete GPU can then be woken to drive the newly connected display.
308 * The ability to switch AUX on these generations could be used to improve
309 * reliability of hotplug detection by having the integrated GPU poll the
310 * ports while the discrete GPU is asleep, but currently we do not make use
311 * of this feature.
312 *
313 * Our switching policy for the external port is that on those generations
314 * which are able to switch it fully, the port is switched together with the
315 * panel when IGD / DIS commands are issued to vga_switcheroo. It is thus
316 * possible to drive e.g. a beamer on battery power with the integrated GPU.
317 * The user may manually switch to the discrete GPU if more performance is
318 * needed.
319 *
320 * On all newer generations, the external port can only be driven by the
321 * discrete GPU. If a display is plugged in while the panel is switched to
322 * the integrated GPU, *both* GPUs will be in use for maximum performance.
323 * To decrease power consumption, the user may manually switch to the
324 * discrete GPU, thereby suspending the integrated GPU.
325 *
326 * gmux' initial switch state on bootup is user configurable via the EFI
327 * variable ``gpu-power-prefs-fa4ce28d-b62f-4c99-9cc3-6815686e30f9`` (5th byte,
328 * 1 = IGD, 0 = DIS). Based on this setting, the EFI firmware tells gmux to
329 * switch the panel and the external DP connector and allocates a framebuffer
330 * for the selected GPU.
331 *
332 * .. _US 8,687,007 B2: https://pimg-fpiw.uspto.gov/fdd/07/870/086/0.pdf
333 * .. _NXP CBTL06141: https://www.nxp.com/documents/data_sheet/CBTL06141.pdf
334 * .. _NXP CBTL06142: https://www.nxp.com/documents/data_sheet/CBTL06141.pdf
335 * .. _TI HD3SS212: https://www.ti.com/lit/ds/symlink/hd3ss212.pdf
336 * .. _Pericom PI3VDP12412: https://www.pericom.com/assets/Datasheets/PI3VDP12412.pdf
337 * .. _TI SN74LV4066A: https://www.ti.com/lit/ds/symlink/sn74lv4066a.pdf
338 * .. _NXP CBTL03062: http://pdf.datasheetarchive.com/indexerfiles/Datasheets-SW16/DSASW00308511.pdf
339 * .. _TI TS3DS10224: https://www.ti.com/lit/ds/symlink/ts3ds10224.pdf
340 */
341
342static void gmux_read_switch_state(struct apple_gmux_data *gmux_data)
343{
344 if (gmux_read8(gmux_data, GMUX_PORT_SWITCH_DDC) == 1)
345 gmux_data->switch_state_ddc = VGA_SWITCHEROO_IGD;
346 else
347 gmux_data->switch_state_ddc = VGA_SWITCHEROO_DIS;
348
349 if (gmux_read8(gmux_data, GMUX_PORT_SWITCH_DISPLAY) == 2)
350 gmux_data->switch_state_display = VGA_SWITCHEROO_IGD;
351 else
352 gmux_data->switch_state_display = VGA_SWITCHEROO_DIS;
353
354 if (gmux_read8(gmux_data, GMUX_PORT_SWITCH_EXTERNAL) == 2)
355 gmux_data->switch_state_external = VGA_SWITCHEROO_IGD;
356 else
357 gmux_data->switch_state_external = VGA_SWITCHEROO_DIS;
358}
359
360static void gmux_write_switch_state(struct apple_gmux_data *gmux_data)
361{
362 if (gmux_data->switch_state_ddc == VGA_SWITCHEROO_IGD)
363 gmux_write8(gmux_data, GMUX_PORT_SWITCH_DDC, 1);
364 else
365 gmux_write8(gmux_data, GMUX_PORT_SWITCH_DDC, 2);
366
367 if (gmux_data->switch_state_display == VGA_SWITCHEROO_IGD)
368 gmux_write8(gmux_data, GMUX_PORT_SWITCH_DISPLAY, 2);
369 else
370 gmux_write8(gmux_data, GMUX_PORT_SWITCH_DISPLAY, 3);
371
372 if (gmux_data->switch_state_external == VGA_SWITCHEROO_IGD)
373 gmux_write8(gmux_data, GMUX_PORT_SWITCH_EXTERNAL, 2);
374 else
375 gmux_write8(gmux_data, GMUX_PORT_SWITCH_EXTERNAL, 3);
376}
377
378static int gmux_switchto(enum vga_switcheroo_client_id id)
379{
380 apple_gmux_data->switch_state_ddc = id;
381 apple_gmux_data->switch_state_display = id;
382 if (apple_gmux_data->external_switchable)
383 apple_gmux_data->switch_state_external = id;
384
385 gmux_write_switch_state(apple_gmux_data);
386
387 return 0;
388}
389
390static int gmux_switch_ddc(enum vga_switcheroo_client_id id)
391{
392 enum vga_switcheroo_client_id old_ddc_owner =
393 apple_gmux_data->switch_state_ddc;
394
395 if (id == old_ddc_owner)
396 return id;
397
398 pr_debug("Switching DDC from %d to %d\n", old_ddc_owner, id);
399 apple_gmux_data->switch_state_ddc = id;
400
401 if (id == VGA_SWITCHEROO_IGD)
402 gmux_write8(apple_gmux_data, GMUX_PORT_SWITCH_DDC, 1);
403 else
404 gmux_write8(apple_gmux_data, GMUX_PORT_SWITCH_DDC, 2);
405
406 return old_ddc_owner;
407}
408
409/**
410 * DOC: Power control
411 *
412 * gmux is able to cut power to the discrete GPU. It automatically takes care
413 * of the correct sequence to tear down and bring up the power rails for
414 * core voltage, VRAM and PCIe.
415 */
416
417static int gmux_set_discrete_state(struct apple_gmux_data *gmux_data,
418 enum vga_switcheroo_state state)
419{
420 reinit_completion(&gmux_data->powerchange_done);
421
422 if (state == VGA_SWITCHEROO_ON) {
423 gmux_write8(gmux_data, GMUX_PORT_DISCRETE_POWER, 1);
424 gmux_write8(gmux_data, GMUX_PORT_DISCRETE_POWER, 3);
425 pr_debug("Discrete card powered up\n");
426 } else {
427 gmux_write8(gmux_data, GMUX_PORT_DISCRETE_POWER, 1);
428 gmux_write8(gmux_data, GMUX_PORT_DISCRETE_POWER, 0);
429 pr_debug("Discrete card powered down\n");
430 }
431
432 gmux_data->power_state = state;
433
434 if (gmux_data->gpe >= 0 &&
435 !wait_for_completion_interruptible_timeout(&gmux_data->powerchange_done,
436 msecs_to_jiffies(200)))
437 pr_warn("Timeout waiting for gmux switch to complete\n");
438
439 return 0;
440}
441
442static int gmux_set_power_state(enum vga_switcheroo_client_id id,
443 enum vga_switcheroo_state state)
444{
445 if (id == VGA_SWITCHEROO_IGD)
446 return 0;
447
448 return gmux_set_discrete_state(apple_gmux_data, state);
449}
450
451static enum vga_switcheroo_client_id gmux_get_client_id(struct pci_dev *pdev)
452{
453 /*
454 * Early Macbook Pros with switchable graphics use nvidia
455 * integrated graphics. Hardcode that the 9400M is integrated.
456 */
457 if (pdev->vendor == PCI_VENDOR_ID_INTEL)
458 return VGA_SWITCHEROO_IGD;
459 else if (pdev->vendor == PCI_VENDOR_ID_NVIDIA &&
460 pdev->device == 0x0863)
461 return VGA_SWITCHEROO_IGD;
462 else
463 return VGA_SWITCHEROO_DIS;
464}
465
466static const struct vga_switcheroo_handler gmux_handler_indexed = {
467 .switchto = gmux_switchto,
468 .power_state = gmux_set_power_state,
469 .get_client_id = gmux_get_client_id,
470};
471
472static const struct vga_switcheroo_handler gmux_handler_classic = {
473 .switchto = gmux_switchto,
474 .switch_ddc = gmux_switch_ddc,
475 .power_state = gmux_set_power_state,
476 .get_client_id = gmux_get_client_id,
477};
478
479/**
480 * DOC: Interrupt
481 *
482 * gmux is also connected to a GPIO pin of the southbridge and thereby is able
483 * to trigger an ACPI GPE. On the MBP5 2008/09 it's GPIO pin 22 of the Nvidia
484 * MCP79, on all following generations it's GPIO pin 6 of the Intel PCH.
485 * The GPE merely signals that an interrupt occurred, the actual type of event
486 * is identified by reading a gmux register.
487 */
488
489static inline void gmux_disable_interrupts(struct apple_gmux_data *gmux_data)
490{
491 gmux_write8(gmux_data, GMUX_PORT_INTERRUPT_ENABLE,
492 GMUX_INTERRUPT_DISABLE);
493}
494
495static inline void gmux_enable_interrupts(struct apple_gmux_data *gmux_data)
496{
497 gmux_write8(gmux_data, GMUX_PORT_INTERRUPT_ENABLE,
498 GMUX_INTERRUPT_ENABLE);
499}
500
501static inline u8 gmux_interrupt_get_status(struct apple_gmux_data *gmux_data)
502{
503 return gmux_read8(gmux_data, GMUX_PORT_INTERRUPT_STATUS);
504}
505
506static void gmux_clear_interrupts(struct apple_gmux_data *gmux_data)
507{
508 u8 status;
509
510 /* to clear interrupts write back current status */
511 status = gmux_interrupt_get_status(gmux_data);
512 gmux_write8(gmux_data, GMUX_PORT_INTERRUPT_STATUS, status);
513}
514
515static void gmux_notify_handler(acpi_handle device, u32 value, void *context)
516{
517 u8 status;
518 struct pnp_dev *pnp = (struct pnp_dev *)context;
519 struct apple_gmux_data *gmux_data = pnp_get_drvdata(pnp);
520
521 status = gmux_interrupt_get_status(gmux_data);
522 gmux_disable_interrupts(gmux_data);
523 pr_debug("Notify handler called: status %d\n", status);
524
525 gmux_clear_interrupts(gmux_data);
526 gmux_enable_interrupts(gmux_data);
527
528 if (status & GMUX_INTERRUPT_STATUS_POWER)
529 complete(&gmux_data->powerchange_done);
530}
531
532static int gmux_suspend(struct device *dev)
533{
534 struct pnp_dev *pnp = to_pnp_dev(dev);
535 struct apple_gmux_data *gmux_data = pnp_get_drvdata(pnp);
536
537 gmux_disable_interrupts(gmux_data);
538 return 0;
539}
540
541static int gmux_resume(struct device *dev)
542{
543 struct pnp_dev *pnp = to_pnp_dev(dev);
544 struct apple_gmux_data *gmux_data = pnp_get_drvdata(pnp);
545
546 gmux_enable_interrupts(gmux_data);
547 gmux_write_switch_state(gmux_data);
548 if (gmux_data->power_state == VGA_SWITCHEROO_OFF)
549 gmux_set_discrete_state(gmux_data, gmux_data->power_state);
550 return 0;
551}
552
553static int is_thunderbolt(struct device *dev, void *data)
554{
555 return to_pci_dev(dev)->is_thunderbolt;
556}
557
558static int gmux_probe(struct pnp_dev *pnp, const struct pnp_device_id *id)
559{
560 struct apple_gmux_data *gmux_data;
561 struct resource *res;
562 struct backlight_properties props;
563 struct backlight_device *bdev;
564 u8 ver_major, ver_minor, ver_release;
565 int ret = -ENXIO;
566 acpi_status status;
567 unsigned long long gpe;
568 bool indexed = false;
569 u32 version;
570
571 if (apple_gmux_data)
572 return -EBUSY;
573
574 if (!apple_gmux_detect(pnp, &indexed)) {
575 pr_info("gmux device not present\n");
576 return -ENODEV;
577 }
578
579 gmux_data = kzalloc(sizeof(*gmux_data), GFP_KERNEL);
580 if (!gmux_data)
581 return -ENOMEM;
582 pnp_set_drvdata(pnp, gmux_data);
583
584 res = pnp_get_resource(pnp, IORESOURCE_IO, 0);
585 gmux_data->iostart = res->start;
586 gmux_data->iolen = resource_size(res);
587
588 if (!request_region(gmux_data->iostart, gmux_data->iolen,
589 "Apple gmux")) {
590 pr_err("gmux I/O already in use\n");
591 goto err_free;
592 }
593
594 if (indexed) {
595 mutex_init(&gmux_data->index_lock);
596 gmux_data->indexed = true;
597 version = gmux_read32(gmux_data, GMUX_PORT_VERSION_MAJOR);
598 ver_major = (version >> 24) & 0xff;
599 ver_minor = (version >> 16) & 0xff;
600 ver_release = (version >> 8) & 0xff;
601 } else {
602 ver_major = gmux_read8(gmux_data, GMUX_PORT_VERSION_MAJOR);
603 ver_minor = gmux_read8(gmux_data, GMUX_PORT_VERSION_MINOR);
604 ver_release = gmux_read8(gmux_data, GMUX_PORT_VERSION_RELEASE);
605 }
606 pr_info("Found gmux version %d.%d.%d [%s]\n", ver_major, ver_minor,
607 ver_release, (gmux_data->indexed ? "indexed" : "classic"));
608
609 memset(&props, 0, sizeof(props));
610 props.type = BACKLIGHT_PLATFORM;
611 props.max_brightness = gmux_read32(gmux_data, GMUX_PORT_MAX_BRIGHTNESS);
612
613 /*
614 * Currently it's assumed that the maximum brightness is less than
615 * 2^24 for compatibility with old gmux versions. Cap the max
616 * brightness at this value, but print a warning if the hardware
617 * reports something higher so that it can be fixed.
618 */
619 if (WARN_ON(props.max_brightness > GMUX_MAX_BRIGHTNESS))
620 props.max_brightness = GMUX_MAX_BRIGHTNESS;
621
622 bdev = backlight_device_register("gmux_backlight", &pnp->dev,
623 gmux_data, &gmux_bl_ops, &props);
624 if (IS_ERR(bdev)) {
625 ret = PTR_ERR(bdev);
626 goto err_release;
627 }
628
629 gmux_data->bdev = bdev;
630 bdev->props.brightness = gmux_get_brightness(bdev);
631 backlight_update_status(bdev);
632
633 /*
634 * The backlight situation on Macs is complicated. If the gmux is
635 * present it's the best choice, because it always works for
636 * backlight control and supports more levels than other options.
637 * Disable the other backlight choices.
638 */
639 apple_bl_unregister();
640
641 gmux_data->power_state = VGA_SWITCHEROO_ON;
642
643 gmux_data->dhandle = ACPI_HANDLE(&pnp->dev);
644 if (!gmux_data->dhandle) {
645 pr_err("Cannot find acpi handle for pnp device %s\n",
646 dev_name(&pnp->dev));
647 ret = -ENODEV;
648 goto err_notify;
649 }
650
651 status = acpi_evaluate_integer(gmux_data->dhandle, "GMGP", NULL, &gpe);
652 if (ACPI_SUCCESS(status)) {
653 gmux_data->gpe = (int)gpe;
654
655 status = acpi_install_notify_handler(gmux_data->dhandle,
656 ACPI_DEVICE_NOTIFY,
657 &gmux_notify_handler, pnp);
658 if (ACPI_FAILURE(status)) {
659 pr_err("Install notify handler failed: %s\n",
660 acpi_format_exception(status));
661 ret = -ENODEV;
662 goto err_notify;
663 }
664
665 status = acpi_enable_gpe(NULL, gmux_data->gpe);
666 if (ACPI_FAILURE(status)) {
667 pr_err("Cannot enable gpe: %s\n",
668 acpi_format_exception(status));
669 goto err_enable_gpe;
670 }
671 } else {
672 pr_warn("No GPE found for gmux\n");
673 gmux_data->gpe = -1;
674 }
675
676 /*
677 * If Thunderbolt is present, the external DP port is not fully
678 * switchable. Force its AUX channel to the discrete GPU.
679 */
680 gmux_data->external_switchable =
681 !bus_for_each_dev(&pci_bus_type, NULL, NULL, is_thunderbolt);
682 if (!gmux_data->external_switchable)
683 gmux_write8(gmux_data, GMUX_PORT_SWITCH_EXTERNAL, 3);
684
685 apple_gmux_data = gmux_data;
686 init_completion(&gmux_data->powerchange_done);
687 gmux_enable_interrupts(gmux_data);
688 gmux_read_switch_state(gmux_data);
689
690 /*
691 * Retina MacBook Pros cannot switch the panel's AUX separately
692 * and need eDP pre-calibration. They are distinguishable from
693 * pre-retinas by having an "indexed" gmux.
694 *
695 * Pre-retina MacBook Pros can switch the panel's DDC separately.
696 */
697 if (gmux_data->indexed)
698 ret = vga_switcheroo_register_handler(&gmux_handler_indexed,
699 VGA_SWITCHEROO_NEEDS_EDP_CONFIG);
700 else
701 ret = vga_switcheroo_register_handler(&gmux_handler_classic,
702 VGA_SWITCHEROO_CAN_SWITCH_DDC);
703 if (ret) {
704 pr_err("Failed to register vga_switcheroo handler\n");
705 goto err_register_handler;
706 }
707
708 return 0;
709
710err_register_handler:
711 gmux_disable_interrupts(gmux_data);
712 apple_gmux_data = NULL;
713 if (gmux_data->gpe >= 0)
714 acpi_disable_gpe(NULL, gmux_data->gpe);
715err_enable_gpe:
716 if (gmux_data->gpe >= 0)
717 acpi_remove_notify_handler(gmux_data->dhandle,
718 ACPI_DEVICE_NOTIFY,
719 &gmux_notify_handler);
720err_notify:
721 backlight_device_unregister(bdev);
722err_release:
723 release_region(gmux_data->iostart, gmux_data->iolen);
724err_free:
725 kfree(gmux_data);
726 return ret;
727}
728
729static void gmux_remove(struct pnp_dev *pnp)
730{
731 struct apple_gmux_data *gmux_data = pnp_get_drvdata(pnp);
732
733 vga_switcheroo_unregister_handler();
734 gmux_disable_interrupts(gmux_data);
735 if (gmux_data->gpe >= 0) {
736 acpi_disable_gpe(NULL, gmux_data->gpe);
737 acpi_remove_notify_handler(gmux_data->dhandle,
738 ACPI_DEVICE_NOTIFY,
739 &gmux_notify_handler);
740 }
741
742 backlight_device_unregister(gmux_data->bdev);
743
744 release_region(gmux_data->iostart, gmux_data->iolen);
745 apple_gmux_data = NULL;
746 kfree(gmux_data);
747
748 apple_bl_register();
749}
750
751static const struct pnp_device_id gmux_device_ids[] = {
752 {GMUX_ACPI_HID, 0},
753 {"", 0}
754};
755
756static const struct dev_pm_ops gmux_dev_pm_ops = {
757 .suspend = gmux_suspend,
758 .resume = gmux_resume,
759};
760
761static struct pnp_driver gmux_pnp_driver = {
762 .name = "apple-gmux",
763 .probe = gmux_probe,
764 .remove = gmux_remove,
765 .id_table = gmux_device_ids,
766 .driver = {
767 .pm = &gmux_dev_pm_ops,
768 },
769};
770
771module_pnp_driver(gmux_pnp_driver);
772MODULE_AUTHOR("Seth Forshee <seth.forshee@canonical.com>");
773MODULE_DESCRIPTION("Apple Gmux Driver");
774MODULE_LICENSE("GPL");
775MODULE_DEVICE_TABLE(pnp, gmux_device_ids);
1/*
2 * Gmux driver for Apple laptops
3 *
4 * Copyright (C) Canonical Ltd. <seth.forshee@canonical.com>
5 * Copyright (C) 2010-2012 Andreas Heider <andreas@meetr.de>
6 * Copyright (C) 2015 Lukas Wunner <lukas@wunner.de>
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 */
12
13#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
14
15#include <linux/module.h>
16#include <linux/kernel.h>
17#include <linux/init.h>
18#include <linux/backlight.h>
19#include <linux/acpi.h>
20#include <linux/pnp.h>
21#include <linux/apple_bl.h>
22#include <linux/apple-gmux.h>
23#include <linux/slab.h>
24#include <linux/delay.h>
25#include <linux/pci.h>
26#include <linux/vga_switcheroo.h>
27#include <linux/vgaarb.h>
28#include <acpi/video.h>
29#include <asm/io.h>
30
31/**
32 * DOC: Overview
33 *
34 * gmux is a microcontroller built into the MacBook Pro to support dual GPUs:
35 * A `Lattice XP2`_ on pre-retinas, a `Renesas R4F2113`_ on retinas.
36 *
37 * (The MacPro6,1 2013 also has a gmux, however it is unclear why since it has
38 * dual GPUs but no built-in display.)
39 *
40 * gmux is connected to the LPC bus of the southbridge. Its I/O ports are
41 * accessed differently depending on the microcontroller: Driver functions
42 * to access a pre-retina gmux are infixed ``_pio_``, those for a retina gmux
43 * are infixed ``_index_``.
44 *
45 * .. _Lattice XP2:
46 * http://www.latticesemi.com/en/Products/FPGAandCPLD/LatticeXP2.aspx
47 * .. _Renesas R4F2113:
48 * http://www.renesas.com/products/mpumcu/h8s/h8s2100/h8s2113/index.jsp
49 */
50
51struct apple_gmux_data {
52 unsigned long iostart;
53 unsigned long iolen;
54 bool indexed;
55 struct mutex index_lock;
56
57 struct pci_dev *pdev;
58 struct backlight_device *bdev;
59
60 /* switcheroo data */
61 acpi_handle dhandle;
62 int gpe;
63 enum vga_switcheroo_client_id switch_state_display;
64 enum vga_switcheroo_client_id switch_state_ddc;
65 enum vga_switcheroo_client_id switch_state_external;
66 enum vga_switcheroo_state power_state;
67 struct completion powerchange_done;
68};
69
70static struct apple_gmux_data *apple_gmux_data;
71
72/*
73 * gmux port offsets. Many of these are not yet used, but may be in the
74 * future, and it's useful to have them documented here anyhow.
75 */
76#define GMUX_PORT_VERSION_MAJOR 0x04
77#define GMUX_PORT_VERSION_MINOR 0x05
78#define GMUX_PORT_VERSION_RELEASE 0x06
79#define GMUX_PORT_SWITCH_DISPLAY 0x10
80#define GMUX_PORT_SWITCH_GET_DISPLAY 0x11
81#define GMUX_PORT_INTERRUPT_ENABLE 0x14
82#define GMUX_PORT_INTERRUPT_STATUS 0x16
83#define GMUX_PORT_SWITCH_DDC 0x28
84#define GMUX_PORT_SWITCH_EXTERNAL 0x40
85#define GMUX_PORT_SWITCH_GET_EXTERNAL 0x41
86#define GMUX_PORT_DISCRETE_POWER 0x50
87#define GMUX_PORT_MAX_BRIGHTNESS 0x70
88#define GMUX_PORT_BRIGHTNESS 0x74
89#define GMUX_PORT_VALUE 0xc2
90#define GMUX_PORT_READ 0xd0
91#define GMUX_PORT_WRITE 0xd4
92
93#define GMUX_MIN_IO_LEN (GMUX_PORT_BRIGHTNESS + 4)
94
95#define GMUX_INTERRUPT_ENABLE 0xff
96#define GMUX_INTERRUPT_DISABLE 0x00
97
98#define GMUX_INTERRUPT_STATUS_ACTIVE 0
99#define GMUX_INTERRUPT_STATUS_DISPLAY (1 << 0)
100#define GMUX_INTERRUPT_STATUS_POWER (1 << 2)
101#define GMUX_INTERRUPT_STATUS_HOTPLUG (1 << 3)
102
103#define GMUX_BRIGHTNESS_MASK 0x00ffffff
104#define GMUX_MAX_BRIGHTNESS GMUX_BRIGHTNESS_MASK
105
106static u8 gmux_pio_read8(struct apple_gmux_data *gmux_data, int port)
107{
108 return inb(gmux_data->iostart + port);
109}
110
111static void gmux_pio_write8(struct apple_gmux_data *gmux_data, int port,
112 u8 val)
113{
114 outb(val, gmux_data->iostart + port);
115}
116
117static u32 gmux_pio_read32(struct apple_gmux_data *gmux_data, int port)
118{
119 return inl(gmux_data->iostart + port);
120}
121
122static void gmux_pio_write32(struct apple_gmux_data *gmux_data, int port,
123 u32 val)
124{
125 int i;
126 u8 tmpval;
127
128 for (i = 0; i < 4; i++) {
129 tmpval = (val >> (i * 8)) & 0xff;
130 outb(tmpval, gmux_data->iostart + port + i);
131 }
132}
133
134static int gmux_index_wait_ready(struct apple_gmux_data *gmux_data)
135{
136 int i = 200;
137 u8 gwr = inb(gmux_data->iostart + GMUX_PORT_WRITE);
138
139 while (i && (gwr & 0x01)) {
140 inb(gmux_data->iostart + GMUX_PORT_READ);
141 gwr = inb(gmux_data->iostart + GMUX_PORT_WRITE);
142 udelay(100);
143 i--;
144 }
145
146 return !!i;
147}
148
149static int gmux_index_wait_complete(struct apple_gmux_data *gmux_data)
150{
151 int i = 200;
152 u8 gwr = inb(gmux_data->iostart + GMUX_PORT_WRITE);
153
154 while (i && !(gwr & 0x01)) {
155 gwr = inb(gmux_data->iostart + GMUX_PORT_WRITE);
156 udelay(100);
157 i--;
158 }
159
160 if (gwr & 0x01)
161 inb(gmux_data->iostart + GMUX_PORT_READ);
162
163 return !!i;
164}
165
166static u8 gmux_index_read8(struct apple_gmux_data *gmux_data, int port)
167{
168 u8 val;
169
170 mutex_lock(&gmux_data->index_lock);
171 gmux_index_wait_ready(gmux_data);
172 outb((port & 0xff), gmux_data->iostart + GMUX_PORT_READ);
173 gmux_index_wait_complete(gmux_data);
174 val = inb(gmux_data->iostart + GMUX_PORT_VALUE);
175 mutex_unlock(&gmux_data->index_lock);
176
177 return val;
178}
179
180static void gmux_index_write8(struct apple_gmux_data *gmux_data, int port,
181 u8 val)
182{
183 mutex_lock(&gmux_data->index_lock);
184 outb(val, gmux_data->iostart + GMUX_PORT_VALUE);
185 gmux_index_wait_ready(gmux_data);
186 outb(port & 0xff, gmux_data->iostart + GMUX_PORT_WRITE);
187 gmux_index_wait_complete(gmux_data);
188 mutex_unlock(&gmux_data->index_lock);
189}
190
191static u32 gmux_index_read32(struct apple_gmux_data *gmux_data, int port)
192{
193 u32 val;
194
195 mutex_lock(&gmux_data->index_lock);
196 gmux_index_wait_ready(gmux_data);
197 outb((port & 0xff), gmux_data->iostart + GMUX_PORT_READ);
198 gmux_index_wait_complete(gmux_data);
199 val = inl(gmux_data->iostart + GMUX_PORT_VALUE);
200 mutex_unlock(&gmux_data->index_lock);
201
202 return val;
203}
204
205static void gmux_index_write32(struct apple_gmux_data *gmux_data, int port,
206 u32 val)
207{
208 int i;
209 u8 tmpval;
210
211 mutex_lock(&gmux_data->index_lock);
212
213 for (i = 0; i < 4; i++) {
214 tmpval = (val >> (i * 8)) & 0xff;
215 outb(tmpval, gmux_data->iostart + GMUX_PORT_VALUE + i);
216 }
217
218 gmux_index_wait_ready(gmux_data);
219 outb(port & 0xff, gmux_data->iostart + GMUX_PORT_WRITE);
220 gmux_index_wait_complete(gmux_data);
221 mutex_unlock(&gmux_data->index_lock);
222}
223
224static u8 gmux_read8(struct apple_gmux_data *gmux_data, int port)
225{
226 if (gmux_data->indexed)
227 return gmux_index_read8(gmux_data, port);
228 else
229 return gmux_pio_read8(gmux_data, port);
230}
231
232static void gmux_write8(struct apple_gmux_data *gmux_data, int port, u8 val)
233{
234 if (gmux_data->indexed)
235 gmux_index_write8(gmux_data, port, val);
236 else
237 gmux_pio_write8(gmux_data, port, val);
238}
239
240static u32 gmux_read32(struct apple_gmux_data *gmux_data, int port)
241{
242 if (gmux_data->indexed)
243 return gmux_index_read32(gmux_data, port);
244 else
245 return gmux_pio_read32(gmux_data, port);
246}
247
248static void gmux_write32(struct apple_gmux_data *gmux_data, int port,
249 u32 val)
250{
251 if (gmux_data->indexed)
252 gmux_index_write32(gmux_data, port, val);
253 else
254 gmux_pio_write32(gmux_data, port, val);
255}
256
257static bool gmux_is_indexed(struct apple_gmux_data *gmux_data)
258{
259 u16 val;
260
261 outb(0xaa, gmux_data->iostart + 0xcc);
262 outb(0x55, gmux_data->iostart + 0xcd);
263 outb(0x00, gmux_data->iostart + 0xce);
264
265 val = inb(gmux_data->iostart + 0xcc) |
266 (inb(gmux_data->iostart + 0xcd) << 8);
267
268 if (val == 0x55aa)
269 return true;
270
271 return false;
272}
273
274/**
275 * DOC: Backlight control
276 *
277 * On single GPU MacBooks, the PWM signal for the backlight is generated by
278 * the GPU. On dual GPU MacBook Pros by contrast, either GPU may be suspended
279 * to conserve energy. Hence the PWM signal needs to be generated by a separate
280 * backlight driver which is controlled by gmux. The earliest generation
281 * MBP5 2008/09 uses a `TI LP8543`_ backlight driver. All newer models
282 * use a `TI LP8545`_.
283 *
284 * .. _TI LP8543: http://www.ti.com/lit/ds/symlink/lp8543.pdf
285 * .. _TI LP8545: http://www.ti.com/lit/ds/symlink/lp8545.pdf
286 */
287
288static int gmux_get_brightness(struct backlight_device *bd)
289{
290 struct apple_gmux_data *gmux_data = bl_get_data(bd);
291 return gmux_read32(gmux_data, GMUX_PORT_BRIGHTNESS) &
292 GMUX_BRIGHTNESS_MASK;
293}
294
295static int gmux_update_status(struct backlight_device *bd)
296{
297 struct apple_gmux_data *gmux_data = bl_get_data(bd);
298 u32 brightness = bd->props.brightness;
299
300 if (bd->props.state & BL_CORE_SUSPENDED)
301 return 0;
302
303 gmux_write32(gmux_data, GMUX_PORT_BRIGHTNESS, brightness);
304
305 return 0;
306}
307
308static const struct backlight_ops gmux_bl_ops = {
309 .options = BL_CORE_SUSPENDRESUME,
310 .get_brightness = gmux_get_brightness,
311 .update_status = gmux_update_status,
312};
313
314/**
315 * DOC: Graphics mux
316 *
317 * On pre-retinas, the LVDS outputs of both GPUs feed into gmux which muxes
318 * either of them to the panel. One of the tricks gmux has up its sleeve is
319 * to lengthen the blanking interval of its output during a switch to
320 * synchronize it with the GPU switched to. This allows for a flicker-free
321 * switch that is imperceptible by the user (`US 8,687,007 B2`_).
322 *
323 * On retinas, muxing is no longer done by gmux itself, but by a separate
324 * chip which is controlled by gmux. The chip is triple sourced, it is
325 * either an `NXP CBTL06142`_, `TI HD3SS212`_ or `Pericom PI3VDP12412`_.
326 * The panel is driven with eDP instead of LVDS since the pixel clock
327 * required for retina resolution exceeds LVDS' limits.
328 *
329 * Pre-retinas are able to switch the panel's DDC pins separately.
330 * This is handled by a `TI SN74LV4066A`_ which is controlled by gmux.
331 * The inactive GPU can thus probe the panel's EDID without switching over
332 * the entire panel. Retinas lack this functionality as the chips used for
333 * eDP muxing are incapable of switching the AUX channel separately (see
334 * the linked data sheets, Pericom would be capable but this is unused).
335 * However the retina panel has the NO_AUX_HANDSHAKE_LINK_TRAINING bit set
336 * in its DPCD, allowing the inactive GPU to skip the AUX handshake and
337 * set up the output with link parameters pre-calibrated by the active GPU.
338 *
339 * The external DP port is only fully switchable on the first two unibody
340 * MacBook Pro generations, MBP5 2008/09 and MBP6 2010. This is done by an
341 * `NXP CBTL06141`_ which is controlled by gmux. It's the predecessor of the
342 * eDP mux on retinas, the difference being support for 2.7 versus 5.4 Gbit/s.
343 *
344 * The following MacBook Pro generations replaced the external DP port with a
345 * combined DP/Thunderbolt port and lost the ability to switch it between GPUs,
346 * connecting it either to the discrete GPU or the Thunderbolt controller.
347 * Oddly enough, while the full port is no longer switchable, AUX and HPD
348 * are still switchable by way of an `NXP CBTL03062`_ (on pre-retinas
349 * MBP8 2011 and MBP9 2012) or two `TI TS3DS10224`_ (on retinas) under the
350 * control of gmux. Since the integrated GPU is missing the main link,
351 * external displays appear to it as phantoms which fail to link-train.
352 *
353 * gmux receives the HPD signal of all display connectors and sends an
354 * interrupt on hotplug. On generations which cannot switch external ports,
355 * the discrete GPU can then be woken to drive the newly connected display.
356 * The ability to switch AUX on these generations could be used to improve
357 * reliability of hotplug detection by having the integrated GPU poll the
358 * ports while the discrete GPU is asleep, but currently we do not make use
359 * of this feature.
360 *
361 * gmux' initial switch state on bootup is user configurable via the EFI
362 * variable ``gpu-power-prefs-fa4ce28d-b62f-4c99-9cc3-6815686e30f9`` (5th byte,
363 * 1 = IGD, 0 = DIS). Based on this setting, the EFI firmware tells gmux to
364 * switch the panel and the external DP connector and allocates a framebuffer
365 * for the selected GPU.
366 *
367 * .. _US 8,687,007 B2: http://pimg-fpiw.uspto.gov/fdd/07/870/086/0.pdf
368 * .. _NXP CBTL06141: http://www.nxp.com/documents/data_sheet/CBTL06141.pdf
369 * .. _NXP CBTL06142: http://www.nxp.com/documents/data_sheet/CBTL06141.pdf
370 * .. _TI HD3SS212: http://www.ti.com/lit/ds/symlink/hd3ss212.pdf
371 * .. _Pericom PI3VDP12412: https://www.pericom.com/assets/Datasheets/PI3VDP12412.pdf
372 * .. _TI SN74LV4066A: http://www.ti.com/lit/ds/symlink/sn74lv4066a.pdf
373 * .. _NXP CBTL03062: http://pdf.datasheetarchive.com/indexerfiles/Datasheets-SW16/DSASW00308511.pdf
374 * .. _TI TS3DS10224: http://www.ti.com/lit/ds/symlink/ts3ds10224.pdf
375 */
376
377static void gmux_read_switch_state(struct apple_gmux_data *gmux_data)
378{
379 if (gmux_read8(gmux_data, GMUX_PORT_SWITCH_DDC) == 1)
380 gmux_data->switch_state_ddc = VGA_SWITCHEROO_IGD;
381 else
382 gmux_data->switch_state_ddc = VGA_SWITCHEROO_DIS;
383
384 if (gmux_read8(gmux_data, GMUX_PORT_SWITCH_DISPLAY) == 2)
385 gmux_data->switch_state_display = VGA_SWITCHEROO_IGD;
386 else
387 gmux_data->switch_state_display = VGA_SWITCHEROO_DIS;
388
389 if (gmux_read8(gmux_data, GMUX_PORT_SWITCH_EXTERNAL) == 2)
390 gmux_data->switch_state_external = VGA_SWITCHEROO_IGD;
391 else
392 gmux_data->switch_state_external = VGA_SWITCHEROO_DIS;
393}
394
395static void gmux_write_switch_state(struct apple_gmux_data *gmux_data)
396{
397 if (gmux_data->switch_state_ddc == VGA_SWITCHEROO_IGD)
398 gmux_write8(gmux_data, GMUX_PORT_SWITCH_DDC, 1);
399 else
400 gmux_write8(gmux_data, GMUX_PORT_SWITCH_DDC, 2);
401
402 if (gmux_data->switch_state_display == VGA_SWITCHEROO_IGD)
403 gmux_write8(gmux_data, GMUX_PORT_SWITCH_DISPLAY, 2);
404 else
405 gmux_write8(gmux_data, GMUX_PORT_SWITCH_DISPLAY, 3);
406
407 if (gmux_data->switch_state_external == VGA_SWITCHEROO_IGD)
408 gmux_write8(gmux_data, GMUX_PORT_SWITCH_EXTERNAL, 2);
409 else
410 gmux_write8(gmux_data, GMUX_PORT_SWITCH_EXTERNAL, 3);
411}
412
413static int gmux_switchto(enum vga_switcheroo_client_id id)
414{
415 apple_gmux_data->switch_state_ddc = id;
416 apple_gmux_data->switch_state_display = id;
417 apple_gmux_data->switch_state_external = id;
418
419 gmux_write_switch_state(apple_gmux_data);
420
421 return 0;
422}
423
424static int gmux_switch_ddc(enum vga_switcheroo_client_id id)
425{
426 enum vga_switcheroo_client_id old_ddc_owner =
427 apple_gmux_data->switch_state_ddc;
428
429 if (id == old_ddc_owner)
430 return id;
431
432 pr_debug("Switching DDC from %d to %d\n", old_ddc_owner, id);
433 apple_gmux_data->switch_state_ddc = id;
434
435 if (id == VGA_SWITCHEROO_IGD)
436 gmux_write8(apple_gmux_data, GMUX_PORT_SWITCH_DDC, 1);
437 else
438 gmux_write8(apple_gmux_data, GMUX_PORT_SWITCH_DDC, 2);
439
440 return old_ddc_owner;
441}
442
443/**
444 * DOC: Power control
445 *
446 * gmux is able to cut power to the discrete GPU. It automatically takes care
447 * of the correct sequence to tear down and bring up the power rails for
448 * core voltage, VRAM and PCIe.
449 */
450
451static int gmux_set_discrete_state(struct apple_gmux_data *gmux_data,
452 enum vga_switcheroo_state state)
453{
454 reinit_completion(&gmux_data->powerchange_done);
455
456 if (state == VGA_SWITCHEROO_ON) {
457 gmux_write8(gmux_data, GMUX_PORT_DISCRETE_POWER, 1);
458 gmux_write8(gmux_data, GMUX_PORT_DISCRETE_POWER, 3);
459 pr_debug("Discrete card powered up\n");
460 } else {
461 gmux_write8(gmux_data, GMUX_PORT_DISCRETE_POWER, 1);
462 gmux_write8(gmux_data, GMUX_PORT_DISCRETE_POWER, 0);
463 pr_debug("Discrete card powered down\n");
464 }
465
466 gmux_data->power_state = state;
467
468 if (gmux_data->gpe >= 0 &&
469 !wait_for_completion_interruptible_timeout(&gmux_data->powerchange_done,
470 msecs_to_jiffies(200)))
471 pr_warn("Timeout waiting for gmux switch to complete\n");
472
473 return 0;
474}
475
476static int gmux_set_power_state(enum vga_switcheroo_client_id id,
477 enum vga_switcheroo_state state)
478{
479 if (id == VGA_SWITCHEROO_IGD)
480 return 0;
481
482 return gmux_set_discrete_state(apple_gmux_data, state);
483}
484
485static int gmux_get_client_id(struct pci_dev *pdev)
486{
487 /*
488 * Early Macbook Pros with switchable graphics use nvidia
489 * integrated graphics. Hardcode that the 9400M is integrated.
490 */
491 if (pdev->vendor == PCI_VENDOR_ID_INTEL)
492 return VGA_SWITCHEROO_IGD;
493 else if (pdev->vendor == PCI_VENDOR_ID_NVIDIA &&
494 pdev->device == 0x0863)
495 return VGA_SWITCHEROO_IGD;
496 else
497 return VGA_SWITCHEROO_DIS;
498}
499
500static const struct vga_switcheroo_handler gmux_handler_indexed = {
501 .switchto = gmux_switchto,
502 .power_state = gmux_set_power_state,
503 .get_client_id = gmux_get_client_id,
504};
505
506static const struct vga_switcheroo_handler gmux_handler_classic = {
507 .switchto = gmux_switchto,
508 .switch_ddc = gmux_switch_ddc,
509 .power_state = gmux_set_power_state,
510 .get_client_id = gmux_get_client_id,
511};
512
513/**
514 * DOC: Interrupt
515 *
516 * gmux is also connected to a GPIO pin of the southbridge and thereby is able
517 * to trigger an ACPI GPE. On the MBP5 2008/09 it's GPIO pin 22 of the Nvidia
518 * MCP79, on all following generations it's GPIO pin 6 of the Intel PCH.
519 * The GPE merely signals that an interrupt occurred, the actual type of event
520 * is identified by reading a gmux register.
521 */
522
523static inline void gmux_disable_interrupts(struct apple_gmux_data *gmux_data)
524{
525 gmux_write8(gmux_data, GMUX_PORT_INTERRUPT_ENABLE,
526 GMUX_INTERRUPT_DISABLE);
527}
528
529static inline void gmux_enable_interrupts(struct apple_gmux_data *gmux_data)
530{
531 gmux_write8(gmux_data, GMUX_PORT_INTERRUPT_ENABLE,
532 GMUX_INTERRUPT_ENABLE);
533}
534
535static inline u8 gmux_interrupt_get_status(struct apple_gmux_data *gmux_data)
536{
537 return gmux_read8(gmux_data, GMUX_PORT_INTERRUPT_STATUS);
538}
539
540static void gmux_clear_interrupts(struct apple_gmux_data *gmux_data)
541{
542 u8 status;
543
544 /* to clear interrupts write back current status */
545 status = gmux_interrupt_get_status(gmux_data);
546 gmux_write8(gmux_data, GMUX_PORT_INTERRUPT_STATUS, status);
547}
548
549static void gmux_notify_handler(acpi_handle device, u32 value, void *context)
550{
551 u8 status;
552 struct pnp_dev *pnp = (struct pnp_dev *)context;
553 struct apple_gmux_data *gmux_data = pnp_get_drvdata(pnp);
554
555 status = gmux_interrupt_get_status(gmux_data);
556 gmux_disable_interrupts(gmux_data);
557 pr_debug("Notify handler called: status %d\n", status);
558
559 gmux_clear_interrupts(gmux_data);
560 gmux_enable_interrupts(gmux_data);
561
562 if (status & GMUX_INTERRUPT_STATUS_POWER)
563 complete(&gmux_data->powerchange_done);
564}
565
566static int gmux_suspend(struct device *dev)
567{
568 struct pnp_dev *pnp = to_pnp_dev(dev);
569 struct apple_gmux_data *gmux_data = pnp_get_drvdata(pnp);
570
571 gmux_disable_interrupts(gmux_data);
572 return 0;
573}
574
575static int gmux_resume(struct device *dev)
576{
577 struct pnp_dev *pnp = to_pnp_dev(dev);
578 struct apple_gmux_data *gmux_data = pnp_get_drvdata(pnp);
579
580 gmux_enable_interrupts(gmux_data);
581 gmux_write_switch_state(gmux_data);
582 if (gmux_data->power_state == VGA_SWITCHEROO_OFF)
583 gmux_set_discrete_state(gmux_data, gmux_data->power_state);
584 return 0;
585}
586
587static struct pci_dev *gmux_get_io_pdev(void)
588{
589 struct pci_dev *pdev = NULL;
590
591 while ((pdev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, pdev))) {
592 u16 cmd;
593
594 pci_read_config_word(pdev, PCI_COMMAND, &cmd);
595 if (!(cmd & PCI_COMMAND_IO))
596 continue;
597
598 return pdev;
599 }
600
601 return NULL;
602}
603
604static int gmux_probe(struct pnp_dev *pnp, const struct pnp_device_id *id)
605{
606 struct apple_gmux_data *gmux_data;
607 struct resource *res;
608 struct backlight_properties props;
609 struct backlight_device *bdev;
610 u8 ver_major, ver_minor, ver_release;
611 int ret = -ENXIO;
612 acpi_status status;
613 unsigned long long gpe;
614 struct pci_dev *pdev = NULL;
615
616 if (apple_gmux_data)
617 return -EBUSY;
618
619 gmux_data = kzalloc(sizeof(*gmux_data), GFP_KERNEL);
620 if (!gmux_data)
621 return -ENOMEM;
622 pnp_set_drvdata(pnp, gmux_data);
623
624 res = pnp_get_resource(pnp, IORESOURCE_IO, 0);
625 if (!res) {
626 pr_err("Failed to find gmux I/O resource\n");
627 goto err_free;
628 }
629
630 gmux_data->iostart = res->start;
631 gmux_data->iolen = res->end - res->start;
632
633 if (gmux_data->iolen < GMUX_MIN_IO_LEN) {
634 pr_err("gmux I/O region too small (%lu < %u)\n",
635 gmux_data->iolen, GMUX_MIN_IO_LEN);
636 goto err_free;
637 }
638
639 if (!request_region(gmux_data->iostart, gmux_data->iolen,
640 "Apple gmux")) {
641 pr_err("gmux I/O already in use\n");
642 goto err_free;
643 }
644
645 /*
646 * Invalid version information may indicate either that the gmux
647 * device isn't present or that it's a new one that uses indexed
648 * io
649 */
650
651 ver_major = gmux_read8(gmux_data, GMUX_PORT_VERSION_MAJOR);
652 ver_minor = gmux_read8(gmux_data, GMUX_PORT_VERSION_MINOR);
653 ver_release = gmux_read8(gmux_data, GMUX_PORT_VERSION_RELEASE);
654 if (ver_major == 0xff && ver_minor == 0xff && ver_release == 0xff) {
655 if (gmux_is_indexed(gmux_data)) {
656 u32 version;
657 mutex_init(&gmux_data->index_lock);
658 gmux_data->indexed = true;
659 version = gmux_read32(gmux_data,
660 GMUX_PORT_VERSION_MAJOR);
661 ver_major = (version >> 24) & 0xff;
662 ver_minor = (version >> 16) & 0xff;
663 ver_release = (version >> 8) & 0xff;
664 } else {
665 pr_info("gmux device not present or IO disabled\n");
666 ret = -ENODEV;
667 goto err_release;
668 }
669 }
670 pr_info("Found gmux version %d.%d.%d [%s]\n", ver_major, ver_minor,
671 ver_release, (gmux_data->indexed ? "indexed" : "classic"));
672
673 /*
674 * Apple systems with gmux are EFI based and normally don't use
675 * VGA. In addition changing IO+MEM ownership between IGP and dGPU
676 * disables IO/MEM used for backlight control on some systems.
677 * Lock IO+MEM to GPU with active IO to prevent switch.
678 */
679 pdev = gmux_get_io_pdev();
680 if (pdev && vga_tryget(pdev,
681 VGA_RSRC_NORMAL_IO | VGA_RSRC_NORMAL_MEM)) {
682 pr_err("IO+MEM vgaarb-locking for PCI:%s failed\n",
683 pci_name(pdev));
684 ret = -EBUSY;
685 goto err_release;
686 } else if (pdev)
687 pr_info("locked IO for PCI:%s\n", pci_name(pdev));
688 gmux_data->pdev = pdev;
689
690 memset(&props, 0, sizeof(props));
691 props.type = BACKLIGHT_PLATFORM;
692 props.max_brightness = gmux_read32(gmux_data, GMUX_PORT_MAX_BRIGHTNESS);
693
694 /*
695 * Currently it's assumed that the maximum brightness is less than
696 * 2^24 for compatibility with old gmux versions. Cap the max
697 * brightness at this value, but print a warning if the hardware
698 * reports something higher so that it can be fixed.
699 */
700 if (WARN_ON(props.max_brightness > GMUX_MAX_BRIGHTNESS))
701 props.max_brightness = GMUX_MAX_BRIGHTNESS;
702
703 bdev = backlight_device_register("gmux_backlight", &pnp->dev,
704 gmux_data, &gmux_bl_ops, &props);
705 if (IS_ERR(bdev)) {
706 ret = PTR_ERR(bdev);
707 goto err_release;
708 }
709
710 gmux_data->bdev = bdev;
711 bdev->props.brightness = gmux_get_brightness(bdev);
712 backlight_update_status(bdev);
713
714 /*
715 * The backlight situation on Macs is complicated. If the gmux is
716 * present it's the best choice, because it always works for
717 * backlight control and supports more levels than other options.
718 * Disable the other backlight choices.
719 */
720 acpi_video_set_dmi_backlight_type(acpi_backlight_vendor);
721 apple_bl_unregister();
722
723 gmux_data->power_state = VGA_SWITCHEROO_ON;
724
725 gmux_data->dhandle = ACPI_HANDLE(&pnp->dev);
726 if (!gmux_data->dhandle) {
727 pr_err("Cannot find acpi handle for pnp device %s\n",
728 dev_name(&pnp->dev));
729 ret = -ENODEV;
730 goto err_notify;
731 }
732
733 status = acpi_evaluate_integer(gmux_data->dhandle, "GMGP", NULL, &gpe);
734 if (ACPI_SUCCESS(status)) {
735 gmux_data->gpe = (int)gpe;
736
737 status = acpi_install_notify_handler(gmux_data->dhandle,
738 ACPI_DEVICE_NOTIFY,
739 &gmux_notify_handler, pnp);
740 if (ACPI_FAILURE(status)) {
741 pr_err("Install notify handler failed: %s\n",
742 acpi_format_exception(status));
743 ret = -ENODEV;
744 goto err_notify;
745 }
746
747 status = acpi_enable_gpe(NULL, gmux_data->gpe);
748 if (ACPI_FAILURE(status)) {
749 pr_err("Cannot enable gpe: %s\n",
750 acpi_format_exception(status));
751 goto err_enable_gpe;
752 }
753 } else {
754 pr_warn("No GPE found for gmux\n");
755 gmux_data->gpe = -1;
756 }
757
758 apple_gmux_data = gmux_data;
759 init_completion(&gmux_data->powerchange_done);
760 gmux_enable_interrupts(gmux_data);
761 gmux_read_switch_state(gmux_data);
762
763 /*
764 * Retina MacBook Pros cannot switch the panel's AUX separately
765 * and need eDP pre-calibration. They are distinguishable from
766 * pre-retinas by having an "indexed" gmux.
767 *
768 * Pre-retina MacBook Pros can switch the panel's DDC separately.
769 */
770 if (gmux_data->indexed)
771 ret = vga_switcheroo_register_handler(&gmux_handler_indexed,
772 VGA_SWITCHEROO_NEEDS_EDP_CONFIG);
773 else
774 ret = vga_switcheroo_register_handler(&gmux_handler_classic,
775 VGA_SWITCHEROO_CAN_SWITCH_DDC);
776 if (ret) {
777 pr_err("Failed to register vga_switcheroo handler\n");
778 goto err_register_handler;
779 }
780
781 return 0;
782
783err_register_handler:
784 gmux_disable_interrupts(gmux_data);
785 apple_gmux_data = NULL;
786 if (gmux_data->gpe >= 0)
787 acpi_disable_gpe(NULL, gmux_data->gpe);
788err_enable_gpe:
789 if (gmux_data->gpe >= 0)
790 acpi_remove_notify_handler(gmux_data->dhandle,
791 ACPI_DEVICE_NOTIFY,
792 &gmux_notify_handler);
793err_notify:
794 backlight_device_unregister(bdev);
795err_release:
796 if (gmux_data->pdev)
797 vga_put(gmux_data->pdev,
798 VGA_RSRC_NORMAL_IO | VGA_RSRC_NORMAL_MEM);
799 pci_dev_put(pdev);
800 release_region(gmux_data->iostart, gmux_data->iolen);
801err_free:
802 kfree(gmux_data);
803 return ret;
804}
805
806static void gmux_remove(struct pnp_dev *pnp)
807{
808 struct apple_gmux_data *gmux_data = pnp_get_drvdata(pnp);
809
810 vga_switcheroo_unregister_handler();
811 gmux_disable_interrupts(gmux_data);
812 if (gmux_data->gpe >= 0) {
813 acpi_disable_gpe(NULL, gmux_data->gpe);
814 acpi_remove_notify_handler(gmux_data->dhandle,
815 ACPI_DEVICE_NOTIFY,
816 &gmux_notify_handler);
817 }
818
819 if (gmux_data->pdev) {
820 vga_put(gmux_data->pdev,
821 VGA_RSRC_NORMAL_IO | VGA_RSRC_NORMAL_MEM);
822 pci_dev_put(gmux_data->pdev);
823 }
824 backlight_device_unregister(gmux_data->bdev);
825
826 release_region(gmux_data->iostart, gmux_data->iolen);
827 apple_gmux_data = NULL;
828 kfree(gmux_data);
829
830 acpi_video_register();
831 apple_bl_register();
832}
833
834static const struct pnp_device_id gmux_device_ids[] = {
835 {GMUX_ACPI_HID, 0},
836 {"", 0}
837};
838
839static const struct dev_pm_ops gmux_dev_pm_ops = {
840 .suspend = gmux_suspend,
841 .resume = gmux_resume,
842};
843
844static struct pnp_driver gmux_pnp_driver = {
845 .name = "apple-gmux",
846 .probe = gmux_probe,
847 .remove = gmux_remove,
848 .id_table = gmux_device_ids,
849 .driver = {
850 .pm = &gmux_dev_pm_ops,
851 },
852};
853
854module_pnp_driver(gmux_pnp_driver);
855MODULE_AUTHOR("Seth Forshee <seth.forshee@canonical.com>");
856MODULE_DESCRIPTION("Apple Gmux Driver");
857MODULE_LICENSE("GPL");
858MODULE_DEVICE_TABLE(pnp, gmux_device_ids);