ARM: tegra: dvfs: Update Tegra3 CPU and core voltage dependencies
[linux-2.6.git] / drivers / gpu / vga / vga_switcheroo.c
1 /*
2  * Copyright (c) 2010 Red Hat Inc.
3  * Author : Dave Airlie <airlied@redhat.com>
4  *
5  *
6  * Licensed under GPLv2
7  *
8  * vga_switcheroo.c - Support for laptop with dual GPU using one set of outputs
9
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
13
14  GPU driver interface
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
18  */
19
20 #include <linux/module.h>
21 #include <linux/dmi.h>
22 #include <linux/seq_file.h>
23 #include <linux/uaccess.h>
24 #include <linux/fs.h>
25 #include <linux/debugfs.h>
26 #include <linux/fb.h>
27
28 #include <linux/pci.h>
29 #include <linux/vga_switcheroo.h>
30
31 struct vga_switcheroo_client {
32         struct pci_dev *pdev;
33         struct fb_info *fb_info;
34         int pwr_state;
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);
38         int id;
39         bool active;
40 };
41
42 static DEFINE_MUTEX(vgasr_mutex);
43
44 struct vgasr_priv {
45
46         bool active;
47         bool delayed_switch_active;
48         enum vga_switcheroo_client_id delayed_client_id;
49
50         struct dentry *debugfs_root;
51         struct dentry *switch_file;
52
53         int registered_clients;
54         struct vga_switcheroo_client clients[VGA_SWITCHEROO_MAX_CLIENTS];
55
56         struct vga_switcheroo_handler *handler;
57 };
58
59 static int vga_switcheroo_debugfs_init(struct vgasr_priv *priv);
60 static void vga_switcheroo_debugfs_fini(struct vgasr_priv *priv);
61
62 /* only one switcheroo per system */
63 static struct vgasr_priv vgasr_priv;
64
65 int vga_switcheroo_register_handler(struct vga_switcheroo_handler *handler)
66 {
67         mutex_lock(&vgasr_mutex);
68         if (vgasr_priv.handler) {
69                 mutex_unlock(&vgasr_mutex);
70                 return -EINVAL;
71         }
72
73         vgasr_priv.handler = handler;
74         mutex_unlock(&vgasr_mutex);
75         return 0;
76 }
77 EXPORT_SYMBOL(vga_switcheroo_register_handler);
78
79 void vga_switcheroo_unregister_handler(void)
80 {
81         mutex_lock(&vgasr_mutex);
82         vgasr_priv.handler = NULL;
83         mutex_unlock(&vgasr_mutex);
84 }
85 EXPORT_SYMBOL(vga_switcheroo_unregister_handler);
86
87 static void vga_switcheroo_enable(void)
88 {
89         int i;
90         int ret;
91         /* call the handler to init */
92         vgasr_priv.handler->init();
93
94         for (i = 0; i < VGA_SWITCHEROO_MAX_CLIENTS; i++) {
95                 ret = vgasr_priv.handler->get_client_id(vgasr_priv.clients[i].pdev);
96                 if (ret < 0)
97                         return;
98
99                 vgasr_priv.clients[i].id = ret;
100         }
101         vga_switcheroo_debugfs_init(&vgasr_priv);
102         vgasr_priv.active = true;
103 }
104
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))
109 {
110         int index;
111
112         mutex_lock(&vgasr_mutex);
113         /* don't do IGD vs DIS here */
114         if (vgasr_priv.registered_clients & 1)
115                 index = 1;
116         else
117                 index = 0;
118
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;
127
128         vgasr_priv.registered_clients |= (1 << index);
129
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();
134         }
135         mutex_unlock(&vgasr_mutex);
136         return 0;
137 }
138 EXPORT_SYMBOL(vga_switcheroo_register_client);
139
140 void vga_switcheroo_unregister_client(struct pci_dev *pdev)
141 {
142         int i;
143
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);
148                         break;
149                 }
150         }
151
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);
156 }
157 EXPORT_SYMBOL(vga_switcheroo_unregister_client);
158
159 void vga_switcheroo_client_fb_set(struct pci_dev *pdev,
160                                  struct fb_info *info)
161 {
162         int i;
163
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;
168                         break;
169                 }
170         }
171         mutex_unlock(&vgasr_mutex);
172 }
173 EXPORT_SYMBOL(vga_switcheroo_client_fb_set);
174
175 static int vga_switcheroo_show(struct seq_file *m, void *v)
176 {
177         int i;
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));
185         }
186         mutex_unlock(&vgasr_mutex);
187         return 0;
188 }
189
190 static int vga_switcheroo_debugfs_open(struct inode *inode, struct file *file)
191 {
192         return single_open(file, vga_switcheroo_show, NULL);
193 }
194
195 static int vga_switchon(struct vga_switcheroo_client *client)
196 {
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;
202         return 0;
203 }
204
205 static int vga_switchoff(struct vga_switcheroo_client *client)
206 {
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;
212         return 0;
213 }
214
215 /* stage one happens before delay */
216 static int vga_switchto_stage1(struct vga_switcheroo_client *new_client)
217 {
218         int i;
219         struct vga_switcheroo_client *active = NULL;
220
221         for (i = 0; i < VGA_SWITCHEROO_MAX_CLIENTS; i++) {
222                 if (vgasr_priv.clients[i].active == true) {
223                         active = &vgasr_priv.clients[i];
224                         break;
225                 }
226         }
227         if (!active)
228                 return 0;
229
230         if (new_client->pwr_state == VGA_SWITCHEROO_OFF)
231                 vga_switchon(new_client);
232
233         /* swap shadow resource to denote boot VGA device has changed so X starts on new device */
234         active->pdev->resource[PCI_ROM_RESOURCE].flags &= ~IORESOURCE_ROM_SHADOW;
235         new_client->pdev->resource[PCI_ROM_RESOURCE].flags |= IORESOURCE_ROM_SHADOW;
236         return 0;
237 }
238
239 /* post delay */
240 static int vga_switchto_stage2(struct vga_switcheroo_client *new_client)
241 {
242         int ret;
243         int i;
244         struct vga_switcheroo_client *active = NULL;
245
246         for (i = 0; i < VGA_SWITCHEROO_MAX_CLIENTS; i++) {
247                 if (vgasr_priv.clients[i].active == true) {
248                         active = &vgasr_priv.clients[i];
249                         break;
250                 }
251         }
252         if (!active)
253                 return 0;
254
255         active->active = false;
256
257         if (new_client->fb_info) {
258                 struct fb_event event;
259                 event.info = new_client->fb_info;
260                 fb_notifier_call_chain(FB_EVENT_REMAP_ALL_CONSOLE, &event);
261         }
262
263         ret = vgasr_priv.handler->switchto(new_client->id);
264         if (ret)
265                 return ret;
266
267         if (new_client->reprobe)
268                 new_client->reprobe(new_client->pdev);
269
270         if (active->pwr_state == VGA_SWITCHEROO_ON)
271                 vga_switchoff(active);
272
273         new_client->active = true;
274         return 0;
275 }
276
277 static ssize_t
278 vga_switcheroo_debugfs_write(struct file *filp, const char __user *ubuf,
279                              size_t cnt, loff_t *ppos)
280 {
281         char usercmd[64];
282         const char *pdev_name;
283         int i, ret;
284         bool delay = false, can_switch;
285         bool just_mux = false;
286         int client_id = -1;
287         struct vga_switcheroo_client *client = NULL;
288
289         if (cnt > 63)
290                 cnt = 63;
291
292         if (copy_from_user(usercmd, ubuf, cnt))
293                 return -EFAULT;
294
295         mutex_lock(&vgasr_mutex);
296
297         if (!vgasr_priv.active) {
298                 cnt = -EINVAL;
299                 goto out;
300         }
301
302         /* pwr off the device not in use */
303         if (strncmp(usercmd, "OFF", 3) == 0) {
304                 for (i = 0; i < VGA_SWITCHEROO_MAX_CLIENTS; i++) {
305                         if (vgasr_priv.clients[i].active)
306                                 continue;
307                         if (vgasr_priv.clients[i].pwr_state == VGA_SWITCHEROO_ON)
308                                 vga_switchoff(&vgasr_priv.clients[i]);
309                 }
310                 goto out;
311         }
312         /* pwr on the device not in use */
313         if (strncmp(usercmd, "ON", 2) == 0) {
314                 for (i = 0; i < VGA_SWITCHEROO_MAX_CLIENTS; i++) {
315                         if (vgasr_priv.clients[i].active)
316                                 continue;
317                         if (vgasr_priv.clients[i].pwr_state == VGA_SWITCHEROO_OFF)
318                                 vga_switchon(&vgasr_priv.clients[i]);
319                 }
320                 goto out;
321         }
322
323         /* request a delayed switch - test can we switch now */
324         if (strncmp(usercmd, "DIGD", 4) == 0) {
325                 client_id = VGA_SWITCHEROO_IGD;
326                 delay = true;
327         }
328
329         if (strncmp(usercmd, "DDIS", 4) == 0) {
330                 client_id = VGA_SWITCHEROO_DIS;
331                 delay = true;
332         }
333
334         if (strncmp(usercmd, "IGD", 3) == 0)
335                 client_id = VGA_SWITCHEROO_IGD;
336
337         if (strncmp(usercmd, "DIS", 3) == 0)
338                 client_id = VGA_SWITCHEROO_DIS;
339
340         if (strncmp(usercmd, "MIGD", 4) == 0) {
341                 just_mux = true;
342                 client_id = VGA_SWITCHEROO_IGD;
343         }
344         if (strncmp(usercmd, "MDIS", 4) == 0) {
345                 just_mux = true;
346                 client_id = VGA_SWITCHEROO_DIS;
347         }
348
349         if (client_id == -1)
350                 goto out;
351
352         for (i = 0; i < VGA_SWITCHEROO_MAX_CLIENTS; i++) {
353                 if (vgasr_priv.clients[i].id == client_id) {
354                         client = &vgasr_priv.clients[i];
355                         break;
356                 }
357         }
358
359         vgasr_priv.delayed_switch_active = false;
360
361         if (just_mux) {
362                 ret = vgasr_priv.handler->switchto(client_id);
363                 goto out;
364         }
365
366         if (client->active == true)
367                 goto out;
368
369         /* okay we want a switch - test if devices are willing to switch */
370         can_switch = true;
371         for (i = 0; i < VGA_SWITCHEROO_MAX_CLIENTS; i++) {
372                 can_switch = vgasr_priv.clients[i].can_switch(vgasr_priv.clients[i].pdev);
373                 if (can_switch == false) {
374                         printk(KERN_ERR "vga_switcheroo: client %d refused switch\n", i);
375                         break;
376                 }
377         }
378
379         if (can_switch == false && delay == false)
380                 goto out;
381
382         if (can_switch == true) {
383                 pdev_name = pci_name(client->pdev);
384                 ret = vga_switchto_stage1(client);
385                 if (ret)
386                         printk(KERN_ERR "vga_switcheroo: switching failed stage 1 %d\n", ret);
387
388                 ret = vga_switchto_stage2(client);
389                 if (ret)
390                         printk(KERN_ERR "vga_switcheroo: switching failed stage 2 %d\n", ret);
391
392         } else {
393                 printk(KERN_INFO "vga_switcheroo: setting delayed switch to client %d\n", client->id);
394                 vgasr_priv.delayed_switch_active = true;
395                 vgasr_priv.delayed_client_id = client_id;
396
397                 ret = vga_switchto_stage1(client);
398                 if (ret)
399                         printk(KERN_ERR "vga_switcheroo: delayed switching stage 1 failed %d\n", ret);
400         }
401
402 out:
403         mutex_unlock(&vgasr_mutex);
404         return cnt;
405 }
406
407 static const struct file_operations vga_switcheroo_debugfs_fops = {
408         .owner = THIS_MODULE,
409         .open = vga_switcheroo_debugfs_open,
410         .write = vga_switcheroo_debugfs_write,
411         .read = seq_read,
412         .llseek = seq_lseek,
413         .release = single_release,
414 };
415
416 static void vga_switcheroo_debugfs_fini(struct vgasr_priv *priv)
417 {
418         if (priv->switch_file) {
419                 debugfs_remove(priv->switch_file);
420                 priv->switch_file = NULL;
421         }
422         if (priv->debugfs_root) {
423                 debugfs_remove(priv->debugfs_root);
424                 priv->debugfs_root = NULL;
425         }
426 }
427
428 static int vga_switcheroo_debugfs_init(struct vgasr_priv *priv)
429 {
430         /* already initialised */
431         if (priv->debugfs_root)
432                 return 0;
433         priv->debugfs_root = debugfs_create_dir("vgaswitcheroo", NULL);
434
435         if (!priv->debugfs_root) {
436                 printk(KERN_ERR "vga_switcheroo: Cannot create /sys/kernel/debug/vgaswitcheroo\n");
437                 goto fail;
438         }
439
440         priv->switch_file = debugfs_create_file("switch", 0644,
441                                                 priv->debugfs_root, NULL, &vga_switcheroo_debugfs_fops);
442         if (!priv->switch_file) {
443                 printk(KERN_ERR "vga_switcheroo: cannot create /sys/kernel/debug/vgaswitcheroo/switch\n");
444                 goto fail;
445         }
446         return 0;
447 fail:
448         vga_switcheroo_debugfs_fini(priv);
449         return -1;
450 }
451
452 int vga_switcheroo_process_delayed_switch(void)
453 {
454         struct vga_switcheroo_client *client = NULL;
455         const char *pdev_name;
456         bool can_switch = true;
457         int i;
458         int ret;
459         int err = -EINVAL;
460
461         mutex_lock(&vgasr_mutex);
462         if (!vgasr_priv.delayed_switch_active)
463                 goto err;
464
465         printk(KERN_INFO "vga_switcheroo: processing delayed switch to %d\n", vgasr_priv.delayed_client_id);
466
467         for (i = 0; i < VGA_SWITCHEROO_MAX_CLIENTS; i++) {
468                 if (vgasr_priv.clients[i].id == vgasr_priv.delayed_client_id)
469                         client = &vgasr_priv.clients[i];
470                 can_switch = vgasr_priv.clients[i].can_switch(vgasr_priv.clients[i].pdev);
471                 if (can_switch == false) {
472                         printk(KERN_ERR "vga_switcheroo: client %d refused switch\n", i);
473                         break;
474                 }
475         }
476
477         if (can_switch == false || client == NULL)
478                 goto err;
479
480         pdev_name = pci_name(client->pdev);
481         ret = vga_switchto_stage2(client);
482         if (ret)
483                 printk(KERN_ERR "vga_switcheroo: delayed switching failed stage 2 %d\n", ret);
484
485         vgasr_priv.delayed_switch_active = false;
486         err = 0;
487 err:
488         mutex_unlock(&vgasr_mutex);
489         return err;
490 }
491 EXPORT_SYMBOL(vga_switcheroo_process_delayed_switch);
492