2 * Copyright (c) 2010 Red Hat Inc.
3 * Author : Dave Airlie <airlied@redhat.com>
8 * vga_switcheroo.c - Support for laptop with dual GPU using one set of outputs
10 Switcher interface - methods require for ATPX and DCM
11 - switchto - this throws the output MUX switch
12 - discrete_set_power - sets the power state for the discrete card
15 - set_gpu_state - this should do the equiv of s/r for the card
16 - this should *not* set the discrete power state
17 - switch_check - check if the device is in a position to switch now
20 #include <linux/module.h>
21 #include <linux/seq_file.h>
22 #include <linux/uaccess.h>
24 #include <linux/debugfs.h>
27 #include <linux/pci.h>
28 #include <linux/console.h>
29 #include <linux/vga_switcheroo.h>
31 #include <linux/vgaarb.h>
33 struct vga_switcheroo_client
{
35 struct fb_info
*fb_info
;
37 const struct vga_switcheroo_client_ops
*ops
;
40 struct list_head list
;
43 static DEFINE_MUTEX(vgasr_mutex
);
48 bool delayed_switch_active
;
49 enum vga_switcheroo_client_id delayed_client_id
;
51 struct dentry
*debugfs_root
;
52 struct dentry
*switch_file
;
54 int registered_clients
;
55 struct list_head clients
;
57 struct vga_switcheroo_handler
*handler
;
60 #define ID_BIT_AUDIO 0x100
61 #define client_is_audio(c) ((c)->id & ID_BIT_AUDIO)
62 #define client_is_vga(c) ((c)->id == -1 || !client_is_audio(c))
63 #define client_id(c) ((c)->id & ~ID_BIT_AUDIO)
65 static int vga_switcheroo_debugfs_init(struct vgasr_priv
*priv
);
66 static void vga_switcheroo_debugfs_fini(struct vgasr_priv
*priv
);
68 /* only one switcheroo per system */
69 static struct vgasr_priv vgasr_priv
= {
70 .clients
= LIST_HEAD_INIT(vgasr_priv
.clients
),
73 static bool vga_switcheroo_ready(void)
75 /* we're ready if we get two clients + handler */
76 return !vgasr_priv
.active
&&
77 vgasr_priv
.registered_clients
== 2 && vgasr_priv
.handler
;
80 static void vga_switcheroo_enable(void)
83 struct vga_switcheroo_client
*client
;
85 /* call the handler to init */
86 if (vgasr_priv
.handler
->init
)
87 vgasr_priv
.handler
->init();
89 list_for_each_entry(client
, &vgasr_priv
.clients
, list
) {
92 ret
= vgasr_priv
.handler
->get_client_id(client
->pdev
);
98 vga_switcheroo_debugfs_init(&vgasr_priv
);
99 vgasr_priv
.active
= true;
102 int vga_switcheroo_register_handler(struct vga_switcheroo_handler
*handler
)
104 mutex_lock(&vgasr_mutex
);
105 if (vgasr_priv
.handler
) {
106 mutex_unlock(&vgasr_mutex
);
110 vgasr_priv
.handler
= handler
;
111 if (vga_switcheroo_ready()) {
112 printk(KERN_INFO
"vga_switcheroo: enabled\n");
113 vga_switcheroo_enable();
115 mutex_unlock(&vgasr_mutex
);
118 EXPORT_SYMBOL(vga_switcheroo_register_handler
);
120 void vga_switcheroo_unregister_handler(void)
122 mutex_lock(&vgasr_mutex
);
123 vgasr_priv
.handler
= NULL
;
124 if (vgasr_priv
.active
) {
125 pr_info("vga_switcheroo: disabled\n");
126 vga_switcheroo_debugfs_fini(&vgasr_priv
);
127 vgasr_priv
.active
= false;
129 mutex_unlock(&vgasr_mutex
);
131 EXPORT_SYMBOL(vga_switcheroo_unregister_handler
);
133 static int register_client(struct pci_dev
*pdev
,
134 const struct vga_switcheroo_client_ops
*ops
,
137 struct vga_switcheroo_client
*client
;
139 client
= kzalloc(sizeof(*client
), GFP_KERNEL
);
143 client
->pwr_state
= VGA_SWITCHEROO_ON
;
147 client
->active
= active
;
149 mutex_lock(&vgasr_mutex
);
150 list_add_tail(&client
->list
, &vgasr_priv
.clients
);
151 if (client_is_vga(client
))
152 vgasr_priv
.registered_clients
++;
154 if (vga_switcheroo_ready()) {
155 printk(KERN_INFO
"vga_switcheroo: enabled\n");
156 vga_switcheroo_enable();
158 mutex_unlock(&vgasr_mutex
);
162 int vga_switcheroo_register_client(struct pci_dev
*pdev
,
163 const struct vga_switcheroo_client_ops
*ops
)
165 return register_client(pdev
, ops
, -1,
166 pdev
== vga_default_device());
168 EXPORT_SYMBOL(vga_switcheroo_register_client
);
170 int vga_switcheroo_register_audio_client(struct pci_dev
*pdev
,
171 const struct vga_switcheroo_client_ops
*ops
,
174 return register_client(pdev
, ops
, id
| ID_BIT_AUDIO
, active
);
176 EXPORT_SYMBOL(vga_switcheroo_register_audio_client
);
178 static struct vga_switcheroo_client
*
179 find_client_from_pci(struct list_head
*head
, struct pci_dev
*pdev
)
181 struct vga_switcheroo_client
*client
;
182 list_for_each_entry(client
, head
, list
)
183 if (client
->pdev
== pdev
)
188 static struct vga_switcheroo_client
*
189 find_client_from_id(struct list_head
*head
, int client_id
)
191 struct vga_switcheroo_client
*client
;
192 list_for_each_entry(client
, head
, list
)
193 if (client
->id
== client_id
)
198 static struct vga_switcheroo_client
*
199 find_active_client(struct list_head
*head
)
201 struct vga_switcheroo_client
*client
;
202 list_for_each_entry(client
, head
, list
)
203 if (client
->active
&& client_is_vga(client
))
208 int vga_switcheroo_get_client_state(struct pci_dev
*pdev
)
210 struct vga_switcheroo_client
*client
;
212 client
= find_client_from_pci(&vgasr_priv
.clients
, pdev
);
214 return VGA_SWITCHEROO_NOT_FOUND
;
215 if (!vgasr_priv
.active
)
216 return VGA_SWITCHEROO_INIT
;
217 return client
->pwr_state
;
219 EXPORT_SYMBOL(vga_switcheroo_get_client_state
);
221 void vga_switcheroo_unregister_client(struct pci_dev
*pdev
)
223 struct vga_switcheroo_client
*client
;
225 mutex_lock(&vgasr_mutex
);
226 client
= find_client_from_pci(&vgasr_priv
.clients
, pdev
);
228 if (client_is_vga(client
))
229 vgasr_priv
.registered_clients
--;
230 list_del(&client
->list
);
233 if (vgasr_priv
.active
&& vgasr_priv
.registered_clients
< 2) {
234 printk(KERN_INFO
"vga_switcheroo: disabled\n");
235 vga_switcheroo_debugfs_fini(&vgasr_priv
);
236 vgasr_priv
.active
= false;
238 mutex_unlock(&vgasr_mutex
);
240 EXPORT_SYMBOL(vga_switcheroo_unregister_client
);
242 void vga_switcheroo_client_fb_set(struct pci_dev
*pdev
,
243 struct fb_info
*info
)
245 struct vga_switcheroo_client
*client
;
247 mutex_lock(&vgasr_mutex
);
248 client
= find_client_from_pci(&vgasr_priv
.clients
, pdev
);
250 client
->fb_info
= info
;
251 mutex_unlock(&vgasr_mutex
);
253 EXPORT_SYMBOL(vga_switcheroo_client_fb_set
);
255 static int vga_switcheroo_show(struct seq_file
*m
, void *v
)
257 struct vga_switcheroo_client
*client
;
259 mutex_lock(&vgasr_mutex
);
260 list_for_each_entry(client
, &vgasr_priv
.clients
, list
) {
261 seq_printf(m
, "%d:%s%s:%c:%s:%s\n", i
,
262 client_id(client
) == VGA_SWITCHEROO_DIS
? "DIS" : "IGD",
263 client_is_vga(client
) ? "" : "-Audio",
264 client
->active
? '+' : ' ',
265 client
->pwr_state
? "Pwr" : "Off",
266 pci_name(client
->pdev
));
269 mutex_unlock(&vgasr_mutex
);
273 static int vga_switcheroo_debugfs_open(struct inode
*inode
, struct file
*file
)
275 return single_open(file
, vga_switcheroo_show
, NULL
);
278 static int vga_switchon(struct vga_switcheroo_client
*client
)
280 if (vgasr_priv
.handler
->power_state
)
281 vgasr_priv
.handler
->power_state(client
->id
, VGA_SWITCHEROO_ON
);
282 /* call the driver callback to turn on device */
283 client
->ops
->set_gpu_state(client
->pdev
, VGA_SWITCHEROO_ON
);
284 client
->pwr_state
= VGA_SWITCHEROO_ON
;
288 static int vga_switchoff(struct vga_switcheroo_client
*client
)
290 /* call the driver callback to turn off device */
291 client
->ops
->set_gpu_state(client
->pdev
, VGA_SWITCHEROO_OFF
);
292 if (vgasr_priv
.handler
->power_state
)
293 vgasr_priv
.handler
->power_state(client
->id
, VGA_SWITCHEROO_OFF
);
294 client
->pwr_state
= VGA_SWITCHEROO_OFF
;
298 static void set_audio_state(int id
, int state
)
300 struct vga_switcheroo_client
*client
;
302 client
= find_client_from_id(&vgasr_priv
.clients
, id
| ID_BIT_AUDIO
);
303 if (client
&& client
->pwr_state
!= state
) {
304 client
->ops
->set_gpu_state(client
->pdev
, state
);
305 client
->pwr_state
= state
;
309 /* stage one happens before delay */
310 static int vga_switchto_stage1(struct vga_switcheroo_client
*new_client
)
312 struct vga_switcheroo_client
*active
;
314 active
= find_active_client(&vgasr_priv
.clients
);
318 if (new_client
->pwr_state
== VGA_SWITCHEROO_OFF
)
319 vga_switchon(new_client
);
321 vga_set_default_device(new_client
->pdev
);
326 static int vga_switchto_stage2(struct vga_switcheroo_client
*new_client
)
329 struct vga_switcheroo_client
*active
;
331 active
= find_active_client(&vgasr_priv
.clients
);
335 active
->active
= false;
337 set_audio_state(active
->id
, VGA_SWITCHEROO_OFF
);
339 if (new_client
->fb_info
) {
340 struct fb_event event
;
342 event
.info
= new_client
->fb_info
;
343 fb_notifier_call_chain(FB_EVENT_REMAP_ALL_CONSOLE
, &event
);
347 ret
= vgasr_priv
.handler
->switchto(new_client
->id
);
351 if (new_client
->ops
->reprobe
)
352 new_client
->ops
->reprobe(new_client
->pdev
);
354 if (active
->pwr_state
== VGA_SWITCHEROO_ON
)
355 vga_switchoff(active
);
357 set_audio_state(new_client
->id
, VGA_SWITCHEROO_ON
);
359 new_client
->active
= true;
363 static bool check_can_switch(void)
365 struct vga_switcheroo_client
*client
;
367 list_for_each_entry(client
, &vgasr_priv
.clients
, list
) {
368 if (!client
->ops
->can_switch(client
->pdev
)) {
369 printk(KERN_ERR
"vga_switcheroo: client %x refused switch\n", client
->id
);
377 vga_switcheroo_debugfs_write(struct file
*filp
, const char __user
*ubuf
,
378 size_t cnt
, loff_t
*ppos
)
382 bool delay
= false, can_switch
;
383 bool just_mux
= false;
385 struct vga_switcheroo_client
*client
= NULL
;
390 if (copy_from_user(usercmd
, ubuf
, cnt
))
393 mutex_lock(&vgasr_mutex
);
395 if (!vgasr_priv
.active
) {
400 /* pwr off the device not in use */
401 if (strncmp(usercmd
, "OFF", 3) == 0) {
402 list_for_each_entry(client
, &vgasr_priv
.clients
, list
) {
403 if (client
->active
|| client_is_audio(client
))
405 set_audio_state(client
->id
, VGA_SWITCHEROO_OFF
);
406 if (client
->pwr_state
== VGA_SWITCHEROO_ON
)
407 vga_switchoff(client
);
411 /* pwr on the device not in use */
412 if (strncmp(usercmd
, "ON", 2) == 0) {
413 list_for_each_entry(client
, &vgasr_priv
.clients
, list
) {
414 if (client
->active
|| client_is_audio(client
))
416 if (client
->pwr_state
== VGA_SWITCHEROO_OFF
)
417 vga_switchon(client
);
418 set_audio_state(client
->id
, VGA_SWITCHEROO_ON
);
423 /* request a delayed switch - test can we switch now */
424 if (strncmp(usercmd
, "DIGD", 4) == 0) {
425 client_id
= VGA_SWITCHEROO_IGD
;
429 if (strncmp(usercmd
, "DDIS", 4) == 0) {
430 client_id
= VGA_SWITCHEROO_DIS
;
434 if (strncmp(usercmd
, "IGD", 3) == 0)
435 client_id
= VGA_SWITCHEROO_IGD
;
437 if (strncmp(usercmd
, "DIS", 3) == 0)
438 client_id
= VGA_SWITCHEROO_DIS
;
440 if (strncmp(usercmd
, "MIGD", 4) == 0) {
442 client_id
= VGA_SWITCHEROO_IGD
;
444 if (strncmp(usercmd
, "MDIS", 4) == 0) {
446 client_id
= VGA_SWITCHEROO_DIS
;
451 client
= find_client_from_id(&vgasr_priv
.clients
, client_id
);
455 vgasr_priv
.delayed_switch_active
= false;
458 ret
= vgasr_priv
.handler
->switchto(client_id
);
465 /* okay we want a switch - test if devices are willing to switch */
466 can_switch
= check_can_switch();
468 if (can_switch
== false && delay
== false)
472 ret
= vga_switchto_stage1(client
);
474 printk(KERN_ERR
"vga_switcheroo: switching failed stage 1 %d\n", ret
);
476 ret
= vga_switchto_stage2(client
);
478 printk(KERN_ERR
"vga_switcheroo: switching failed stage 2 %d\n", ret
);
481 printk(KERN_INFO
"vga_switcheroo: setting delayed switch to client %d\n", client
->id
);
482 vgasr_priv
.delayed_switch_active
= true;
483 vgasr_priv
.delayed_client_id
= client_id
;
485 ret
= vga_switchto_stage1(client
);
487 printk(KERN_ERR
"vga_switcheroo: delayed switching stage 1 failed %d\n", ret
);
491 mutex_unlock(&vgasr_mutex
);
495 static const struct file_operations vga_switcheroo_debugfs_fops
= {
496 .owner
= THIS_MODULE
,
497 .open
= vga_switcheroo_debugfs_open
,
498 .write
= vga_switcheroo_debugfs_write
,
501 .release
= single_release
,
504 static void vga_switcheroo_debugfs_fini(struct vgasr_priv
*priv
)
506 if (priv
->switch_file
) {
507 debugfs_remove(priv
->switch_file
);
508 priv
->switch_file
= NULL
;
510 if (priv
->debugfs_root
) {
511 debugfs_remove(priv
->debugfs_root
);
512 priv
->debugfs_root
= NULL
;
516 static int vga_switcheroo_debugfs_init(struct vgasr_priv
*priv
)
518 /* already initialised */
519 if (priv
->debugfs_root
)
521 priv
->debugfs_root
= debugfs_create_dir("vgaswitcheroo", NULL
);
523 if (!priv
->debugfs_root
) {
524 printk(KERN_ERR
"vga_switcheroo: Cannot create /sys/kernel/debug/vgaswitcheroo\n");
528 priv
->switch_file
= debugfs_create_file("switch", 0644,
529 priv
->debugfs_root
, NULL
, &vga_switcheroo_debugfs_fops
);
530 if (!priv
->switch_file
) {
531 printk(KERN_ERR
"vga_switcheroo: cannot create /sys/kernel/debug/vgaswitcheroo/switch\n");
536 vga_switcheroo_debugfs_fini(priv
);
540 int vga_switcheroo_process_delayed_switch(void)
542 struct vga_switcheroo_client
*client
;
546 mutex_lock(&vgasr_mutex
);
547 if (!vgasr_priv
.delayed_switch_active
)
550 printk(KERN_INFO
"vga_switcheroo: processing delayed switch to %d\n", vgasr_priv
.delayed_client_id
);
552 client
= find_client_from_id(&vgasr_priv
.clients
,
553 vgasr_priv
.delayed_client_id
);
554 if (!client
|| !check_can_switch())
557 ret
= vga_switchto_stage2(client
);
559 printk(KERN_ERR
"vga_switcheroo: delayed switching failed stage 2 %d\n", ret
);
561 vgasr_priv
.delayed_switch_active
= false;
564 mutex_unlock(&vgasr_mutex
);
567 EXPORT_SYMBOL(vga_switcheroo_process_delayed_switch
);