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