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 for (i = 0; i < VGA_SWITCHEROO_MAX_CLIENTS; i++) {
223 if (vgasr_priv.clients[i].active == true) {
224 active = &vgasr_priv.clients[i];
231 /* power up the first device */
232 ret = pci_enable_device(new_client->pdev);
236 if (new_client->pwr_state == VGA_SWITCHEROO_OFF)
237 vga_switchon(new_client);
239 /* swap shadow resource to denote boot VGA device has changed so X starts on new device */
240 active->pdev->resource[PCI_ROM_RESOURCE].flags &= ~IORESOURCE_ROM_SHADOW;
241 new_client->pdev->resource[PCI_ROM_RESOURCE].flags |= IORESOURCE_ROM_SHADOW;
246 static int vga_switchto_stage2(struct vga_switcheroo_client *new_client)
250 struct vga_switcheroo_client *active = NULL;
252 for (i = 0; i < VGA_SWITCHEROO_MAX_CLIENTS; i++) {
253 if (vgasr_priv.clients[i].active == true) {
254 active = &vgasr_priv.clients[i];
261 active->active = false;
263 if (new_client->fb_info) {
264 struct fb_event event;
265 event.info = new_client->fb_info;
266 fb_notifier_call_chain(FB_EVENT_REMAP_ALL_CONSOLE, &event);
269 ret = vgasr_priv.handler->switchto(new_client->id);
273 if (new_client->reprobe)
274 new_client->reprobe(new_client->pdev);
276 if (active->pwr_state == VGA_SWITCHEROO_ON)
277 vga_switchoff(active);
279 new_client->active = true;
284 vga_switcheroo_debugfs_write(struct file *filp, const char __user *ubuf,
285 size_t cnt, loff_t *ppos)
288 const char *pdev_name;
290 bool delay = false, can_switch;
291 bool just_mux = false;
293 struct vga_switcheroo_client *client = NULL;
298 if (copy_from_user(usercmd, ubuf, cnt))
301 mutex_lock(&vgasr_mutex);
303 if (!vgasr_priv.active) {
308 /* pwr off the device not in use */
309 if (strncmp(usercmd, "OFF", 3) == 0) {
310 for (i = 0; i < VGA_SWITCHEROO_MAX_CLIENTS; i++) {
311 if (vgasr_priv.clients[i].active)
313 if (vgasr_priv.clients[i].pwr_state == VGA_SWITCHEROO_ON)
314 vga_switchoff(&vgasr_priv.clients[i]);
318 /* pwr on the device not in use */
319 if (strncmp(usercmd, "ON", 2) == 0) {
320 for (i = 0; i < VGA_SWITCHEROO_MAX_CLIENTS; i++) {
321 if (vgasr_priv.clients[i].active)
323 if (vgasr_priv.clients[i].pwr_state == VGA_SWITCHEROO_OFF)
324 vga_switchon(&vgasr_priv.clients[i]);
329 /* request a delayed switch - test can we switch now */
330 if (strncmp(usercmd, "DIGD", 4) == 0) {
331 client_id = VGA_SWITCHEROO_IGD;
335 if (strncmp(usercmd, "DDIS", 4) == 0) {
336 client_id = VGA_SWITCHEROO_DIS;
340 if (strncmp(usercmd, "IGD", 3) == 0)
341 client_id = VGA_SWITCHEROO_IGD;
343 if (strncmp(usercmd, "DIS", 3) == 0)
344 client_id = VGA_SWITCHEROO_DIS;
346 if (strncmp(usercmd, "MIGD", 4) == 0) {
348 client_id = VGA_SWITCHEROO_IGD;
350 if (strncmp(usercmd, "MDIS", 4) == 0) {
352 client_id = VGA_SWITCHEROO_DIS;
358 for (i = 0; i < VGA_SWITCHEROO_MAX_CLIENTS; i++) {
359 if (vgasr_priv.clients[i].id == client_id) {
360 client = &vgasr_priv.clients[i];
365 vgasr_priv.delayed_switch_active = false;
368 ret = vgasr_priv.handler->switchto(client_id);
372 if (client->active == true)
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);