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/dmi.h>
22 #include <linux/seq_file.h>
23 #include <linux/uaccess.h>
25 #include <linux/debugfs.h>
28 #include <linux/pci.h>
29 #include <linux/vga_switcheroo.h>
31 struct vga_switcheroo_client
{
33 struct fb_info
*fb_info
;
35 void (*set_gpu_state
)(struct pci_dev
*pdev
, enum vga_switcheroo_state
);
36 void (*reprobe
)(struct pci_dev
*pdev
);
37 bool (*can_switch
)(struct pci_dev
*pdev
);
42 static DEFINE_MUTEX(vgasr_mutex
);
47 bool delayed_switch_active
;
48 enum vga_switcheroo_client_id delayed_client_id
;
50 struct dentry
*debugfs_root
;
51 struct dentry
*switch_file
;
53 int registered_clients
;
54 struct vga_switcheroo_client clients
[VGA_SWITCHEROO_MAX_CLIENTS
];
56 struct vga_switcheroo_handler
*handler
;
59 static int vga_switcheroo_debugfs_init(struct vgasr_priv
*priv
);
60 static void vga_switcheroo_debugfs_fini(struct vgasr_priv
*priv
);
62 /* only one switcheroo per system */
63 static struct vgasr_priv vgasr_priv
;
65 int vga_switcheroo_register_handler(struct vga_switcheroo_handler
*handler
)
67 mutex_lock(&vgasr_mutex
);
68 if (vgasr_priv
.handler
) {
69 mutex_unlock(&vgasr_mutex
);
73 vgasr_priv
.handler
= handler
;
74 mutex_unlock(&vgasr_mutex
);
77 EXPORT_SYMBOL(vga_switcheroo_register_handler
);
79 void vga_switcheroo_unregister_handler(void)
81 mutex_lock(&vgasr_mutex
);
82 vgasr_priv
.handler
= NULL
;
83 mutex_unlock(&vgasr_mutex
);
85 EXPORT_SYMBOL(vga_switcheroo_unregister_handler
);
87 static void vga_switcheroo_enable(void)
91 /* call the handler to init */
92 vgasr_priv
.handler
->init();
94 for (i
= 0; i
< VGA_SWITCHEROO_MAX_CLIENTS
; i
++) {
95 ret
= vgasr_priv
.handler
->get_client_id(vgasr_priv
.clients
[i
].pdev
);
99 vgasr_priv
.clients
[i
].id
= ret
;
101 vga_switcheroo_debugfs_init(&vgasr_priv
);
102 vgasr_priv
.active
= true;
105 int vga_switcheroo_register_client(struct pci_dev
*pdev
,
106 void (*set_gpu_state
)(struct pci_dev
*pdev
, enum vga_switcheroo_state
),
107 void (*reprobe
)(struct pci_dev
*pdev
),
108 bool (*can_switch
)(struct pci_dev
*pdev
))
112 mutex_lock(&vgasr_mutex
);
113 /* don't do IGD vs DIS here */
114 if (vgasr_priv
.registered_clients
& 1)
119 vgasr_priv
.clients
[index
].pwr_state
= VGA_SWITCHEROO_ON
;
120 vgasr_priv
.clients
[index
].pdev
= pdev
;
121 vgasr_priv
.clients
[index
].set_gpu_state
= set_gpu_state
;
122 vgasr_priv
.clients
[index
].reprobe
= reprobe
;
123 vgasr_priv
.clients
[index
].can_switch
= can_switch
;
124 vgasr_priv
.clients
[index
].id
= -1;
125 if (pdev
->resource
[PCI_ROM_RESOURCE
].flags
& IORESOURCE_ROM_SHADOW
)
126 vgasr_priv
.clients
[index
].active
= true;
128 vgasr_priv
.registered_clients
|= (1 << index
);
130 /* if we get two clients + handler */
131 if (vgasr_priv
.registered_clients
== 0x3 && vgasr_priv
.handler
) {
132 printk(KERN_INFO
"vga_switcheroo: enabled\n");
133 vga_switcheroo_enable();
135 mutex_unlock(&vgasr_mutex
);
138 EXPORT_SYMBOL(vga_switcheroo_register_client
);
140 void vga_switcheroo_unregister_client(struct pci_dev
*pdev
)
144 mutex_lock(&vgasr_mutex
);
145 for (i
= 0; i
< VGA_SWITCHEROO_MAX_CLIENTS
; i
++) {
146 if (vgasr_priv
.clients
[i
].pdev
== pdev
) {
147 vgasr_priv
.registered_clients
&= ~(1 << i
);
152 printk(KERN_INFO
"vga_switcheroo: disabled\n");
153 vga_switcheroo_debugfs_fini(&vgasr_priv
);
154 vgasr_priv
.active
= false;
155 mutex_unlock(&vgasr_mutex
);
157 EXPORT_SYMBOL(vga_switcheroo_unregister_client
);
159 void vga_switcheroo_client_fb_set(struct pci_dev
*pdev
,
160 struct fb_info
*info
)
164 mutex_lock(&vgasr_mutex
);
165 for (i
= 0; i
< VGA_SWITCHEROO_MAX_CLIENTS
; i
++) {
166 if (vgasr_priv
.clients
[i
].pdev
== pdev
) {
167 vgasr_priv
.clients
[i
].fb_info
= info
;
171 mutex_unlock(&vgasr_mutex
);
173 EXPORT_SYMBOL(vga_switcheroo_client_fb_set
);
175 static int vga_switcheroo_show(struct seq_file
*m
, void *v
)
178 mutex_lock(&vgasr_mutex
);
179 for (i
= 0; i
< VGA_SWITCHEROO_MAX_CLIENTS
; i
++) {
180 seq_printf(m
, "%d:%s:%c:%s:%s\n", i
,
181 vgasr_priv
.clients
[i
].id
== VGA_SWITCHEROO_DIS
? "DIS" : "IGD",
182 vgasr_priv
.clients
[i
].active
? '+' : ' ',
183 vgasr_priv
.clients
[i
].pwr_state
? "Pwr" : "Off",
184 pci_name(vgasr_priv
.clients
[i
].pdev
));
186 mutex_unlock(&vgasr_mutex
);
190 static int vga_switcheroo_debugfs_open(struct inode
*inode
, struct file
*file
)
192 return single_open(file
, vga_switcheroo_show
, NULL
);
195 static int vga_switchon(struct vga_switcheroo_client
*client
)
197 if (vgasr_priv
.handler
->power_state
)
198 vgasr_priv
.handler
->power_state(client
->id
, VGA_SWITCHEROO_ON
);
199 /* call the driver callback to turn on device */
200 client
->set_gpu_state(client
->pdev
, VGA_SWITCHEROO_ON
);
201 client
->pwr_state
= VGA_SWITCHEROO_ON
;
205 static int vga_switchoff(struct vga_switcheroo_client
*client
)
207 /* call the driver callback to turn off device */
208 client
->set_gpu_state(client
->pdev
, VGA_SWITCHEROO_OFF
);
209 if (vgasr_priv
.handler
->power_state
)
210 vgasr_priv
.handler
->power_state(client
->id
, VGA_SWITCHEROO_OFF
);
211 client
->pwr_state
= VGA_SWITCHEROO_OFF
;
215 /* stage one happens before delay */
216 static int vga_switchto_stage1(struct vga_switcheroo_client
*new_client
)
220 struct vga_switcheroo_client
*active
= NULL
;
222 if (new_client
->active
== true)
225 for (i
= 0; i
< VGA_SWITCHEROO_MAX_CLIENTS
; i
++) {
226 if (vgasr_priv
.clients
[i
].active
== true) {
227 active
= &vgasr_priv
.clients
[i
];
234 /* power up the first device */
235 ret
= pci_enable_device(new_client
->pdev
);
239 if (new_client
->pwr_state
== VGA_SWITCHEROO_OFF
)
240 vga_switchon(new_client
);
242 /* swap shadow resource to denote boot VGA device has changed so X starts on new device */
243 active
->pdev
->resource
[PCI_ROM_RESOURCE
].flags
&= ~IORESOURCE_ROM_SHADOW
;
244 new_client
->pdev
->resource
[PCI_ROM_RESOURCE
].flags
|= IORESOURCE_ROM_SHADOW
;
249 static int vga_switchto_stage2(struct vga_switcheroo_client
*new_client
)
253 struct vga_switcheroo_client
*active
= NULL
;
255 for (i
= 0; i
< VGA_SWITCHEROO_MAX_CLIENTS
; i
++) {
256 if (vgasr_priv
.clients
[i
].active
== true) {
257 active
= &vgasr_priv
.clients
[i
];
264 active
->active
= false;
266 if (new_client
->fb_info
) {
267 struct fb_event event
;
268 event
.info
= new_client
->fb_info
;
269 fb_notifier_call_chain(FB_EVENT_REMAP_ALL_CONSOLE
, &event
);
272 ret
= vgasr_priv
.handler
->switchto(new_client
->id
);
276 if (new_client
->reprobe
)
277 new_client
->reprobe(new_client
->pdev
);
279 if (active
->pwr_state
== VGA_SWITCHEROO_ON
)
280 vga_switchoff(active
);
282 new_client
->active
= true;
287 vga_switcheroo_debugfs_write(struct file
*filp
, const char __user
*ubuf
,
288 size_t cnt
, loff_t
*ppos
)
291 const char *pdev_name
;
293 bool delay
= false, can_switch
;
294 bool just_mux
= false;
296 struct vga_switcheroo_client
*client
= NULL
;
301 if (copy_from_user(usercmd
, ubuf
, cnt
))
304 mutex_lock(&vgasr_mutex
);
306 if (!vgasr_priv
.active
) {
311 /* pwr off the device not in use */
312 if (strncmp(usercmd
, "OFF", 3) == 0) {
313 for (i
= 0; i
< VGA_SWITCHEROO_MAX_CLIENTS
; i
++) {
314 if (vgasr_priv
.clients
[i
].active
)
316 if (vgasr_priv
.clients
[i
].pwr_state
== VGA_SWITCHEROO_ON
)
317 vga_switchoff(&vgasr_priv
.clients
[i
]);
321 /* pwr on the device not in use */
322 if (strncmp(usercmd
, "ON", 2) == 0) {
323 for (i
= 0; i
< VGA_SWITCHEROO_MAX_CLIENTS
; i
++) {
324 if (vgasr_priv
.clients
[i
].active
)
326 if (vgasr_priv
.clients
[i
].pwr_state
== VGA_SWITCHEROO_OFF
)
327 vga_switchon(&vgasr_priv
.clients
[i
]);
332 /* request a delayed switch - test can we switch now */
333 if (strncmp(usercmd
, "DIGD", 4) == 0) {
334 client_id
= VGA_SWITCHEROO_IGD
;
338 if (strncmp(usercmd
, "DDIS", 4) == 0) {
339 client_id
= VGA_SWITCHEROO_DIS
;
343 if (strncmp(usercmd
, "IGD", 3) == 0)
344 client_id
= VGA_SWITCHEROO_IGD
;
346 if (strncmp(usercmd
, "DIS", 3) == 0)
347 client_id
= VGA_SWITCHEROO_DIS
;
349 if (strncmp(usercmd
, "MIGD", 4) == 0) {
351 client_id
= VGA_SWITCHEROO_IGD
;
353 if (strncmp(usercmd
, "MDIS", 4) == 0) {
355 client_id
= VGA_SWITCHEROO_DIS
;
361 for (i
= 0; i
< VGA_SWITCHEROO_MAX_CLIENTS
; i
++) {
362 if (vgasr_priv
.clients
[i
].id
== client_id
) {
363 client
= &vgasr_priv
.clients
[i
];
368 vgasr_priv
.delayed_switch_active
= false;
371 ret
= vgasr_priv
.handler
->switchto(client_id
);
375 /* okay we want a switch - test if devices are willing to switch */
377 for (i
= 0; i
< VGA_SWITCHEROO_MAX_CLIENTS
; i
++) {
378 can_switch
= vgasr_priv
.clients
[i
].can_switch(vgasr_priv
.clients
[i
].pdev
);
379 if (can_switch
== false) {
380 printk(KERN_ERR
"vga_switcheroo: client %d refused switch\n", i
);
385 if (can_switch
== false && delay
== false)
388 if (can_switch
== true) {
389 pdev_name
= pci_name(client
->pdev
);
390 ret
= vga_switchto_stage1(client
);
392 printk(KERN_ERR
"vga_switcheroo: switching failed stage 1 %d\n", ret
);
394 ret
= vga_switchto_stage2(client
);
396 printk(KERN_ERR
"vga_switcheroo: switching failed stage 2 %d\n", ret
);
399 printk(KERN_INFO
"vga_switcheroo: setting delayed switch to client %d\n", client
->id
);
400 vgasr_priv
.delayed_switch_active
= true;
401 vgasr_priv
.delayed_client_id
= client_id
;
403 ret
= vga_switchto_stage1(client
);
405 printk(KERN_ERR
"vga_switcheroo: delayed switching stage 1 failed %d\n", ret
);
409 mutex_unlock(&vgasr_mutex
);
413 static const struct file_operations vga_switcheroo_debugfs_fops
= {
414 .owner
= THIS_MODULE
,
415 .open
= vga_switcheroo_debugfs_open
,
416 .write
= vga_switcheroo_debugfs_write
,
419 .release
= single_release
,
422 static void vga_switcheroo_debugfs_fini(struct vgasr_priv
*priv
)
424 if (priv
->switch_file
) {
425 debugfs_remove(priv
->switch_file
);
426 priv
->switch_file
= NULL
;
428 if (priv
->debugfs_root
) {
429 debugfs_remove(priv
->debugfs_root
);
430 priv
->debugfs_root
= NULL
;
434 static int vga_switcheroo_debugfs_init(struct vgasr_priv
*priv
)
436 /* already initialised */
437 if (priv
->debugfs_root
)
439 priv
->debugfs_root
= debugfs_create_dir("vgaswitcheroo", NULL
);
441 if (!priv
->debugfs_root
) {
442 printk(KERN_ERR
"vga_switcheroo: Cannot create /sys/kernel/debug/vgaswitcheroo\n");
446 priv
->switch_file
= debugfs_create_file("switch", 0644,
447 priv
->debugfs_root
, NULL
, &vga_switcheroo_debugfs_fops
);
448 if (!priv
->switch_file
) {
449 printk(KERN_ERR
"vga_switcheroo: cannot create /sys/kernel/debug/vgaswitcheroo/switch\n");
454 vga_switcheroo_debugfs_fini(priv
);
458 int vga_switcheroo_process_delayed_switch(void)
460 struct vga_switcheroo_client
*client
= NULL
;
461 const char *pdev_name
;
462 bool can_switch
= true;
467 mutex_lock(&vgasr_mutex
);
468 if (!vgasr_priv
.delayed_switch_active
)
471 printk(KERN_INFO
"vga_switcheroo: processing delayed switch to %d\n", vgasr_priv
.delayed_client_id
);
473 for (i
= 0; i
< VGA_SWITCHEROO_MAX_CLIENTS
; i
++) {
474 if (vgasr_priv
.clients
[i
].id
== vgasr_priv
.delayed_client_id
)
475 client
= &vgasr_priv
.clients
[i
];
476 can_switch
= vgasr_priv
.clients
[i
].can_switch(vgasr_priv
.clients
[i
].pdev
);
477 if (can_switch
== false) {
478 printk(KERN_ERR
"vga_switcheroo: client %d refused switch\n", i
);
483 if (can_switch
== false || client
== NULL
)
486 pdev_name
= pci_name(client
->pdev
);
487 ret
= vga_switchto_stage2(client
);
489 printk(KERN_ERR
"vga_switcheroo: delayed switching failed stage 2 %d\n", ret
);
491 vgasr_priv
.delayed_switch_active
= false;
494 mutex_unlock(&vgasr_mutex
);
497 EXPORT_SYMBOL(vga_switcheroo_process_delayed_switch
);