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