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 bool (*can_switch)(struct pci_dev *pdev);
41 static DEFINE_MUTEX(vgasr_mutex);
46 bool delayed_switch_active;
47 enum vga_switcheroo_client_id delayed_client_id;
49 struct dentry *debugfs_root;
50 struct dentry *switch_file;
52 int registered_clients;
53 struct vga_switcheroo_client clients[VGA_SWITCHEROO_MAX_CLIENTS];
55 struct vga_switcheroo_handler *handler;
58 static int vga_switcheroo_debugfs_init(struct vgasr_priv *priv);
59 static void vga_switcheroo_debugfs_fini(struct vgasr_priv *priv);
61 /* only one switcheroo per system */
62 static struct vgasr_priv vgasr_priv;
64 int vga_switcheroo_register_handler(struct vga_switcheroo_handler *handler)
66 mutex_lock(&vgasr_mutex);
67 if (vgasr_priv.handler) {
68 mutex_unlock(&vgasr_mutex);
72 vgasr_priv.handler = handler;
73 mutex_unlock(&vgasr_mutex);
76 EXPORT_SYMBOL(vga_switcheroo_register_handler);
78 void vga_switcheroo_unregister_handler(void)
80 mutex_lock(&vgasr_mutex);
81 vgasr_priv.handler = NULL;
82 mutex_unlock(&vgasr_mutex);
84 EXPORT_SYMBOL(vga_switcheroo_unregister_handler);
86 static void vga_switcheroo_enable(void)
90 /* call the handler to init */
91 vgasr_priv.handler->init();
93 for (i = 0; i < VGA_SWITCHEROO_MAX_CLIENTS; i++) {
94 ret = vgasr_priv.handler->get_client_id(vgasr_priv.clients[i].pdev);
98 vgasr_priv.clients[i].id = ret;
100 vga_switcheroo_debugfs_init(&vgasr_priv);
101 vgasr_priv.active = true;
104 int vga_switcheroo_register_client(struct pci_dev *pdev,
105 void (*set_gpu_state)(struct pci_dev *pdev, enum vga_switcheroo_state),
106 bool (*can_switch)(struct pci_dev *pdev))
110 mutex_lock(&vgasr_mutex);
111 /* don't do IGD vs DIS here */
112 if (vgasr_priv.registered_clients & 1)
117 vgasr_priv.clients[index].pwr_state = VGA_SWITCHEROO_ON;
118 vgasr_priv.clients[index].pdev = pdev;
119 vgasr_priv.clients[index].set_gpu_state = set_gpu_state;
120 vgasr_priv.clients[index].can_switch = can_switch;
121 vgasr_priv.clients[index].id = -1;
122 if (pdev->resource[PCI_ROM_RESOURCE].flags & IORESOURCE_ROM_SHADOW)
123 vgasr_priv.clients[index].active = true;
125 vgasr_priv.registered_clients |= (1 << index);
127 /* if we get two clients + handler */
128 if (vgasr_priv.registered_clients == 0x3 && vgasr_priv.handler) {
129 printk(KERN_INFO "vga_switcheroo: enabled\n");
130 vga_switcheroo_enable();
132 mutex_unlock(&vgasr_mutex);
135 EXPORT_SYMBOL(vga_switcheroo_register_client);
137 void vga_switcheroo_unregister_client(struct pci_dev *pdev)
141 mutex_lock(&vgasr_mutex);
142 for (i = 0; i < VGA_SWITCHEROO_MAX_CLIENTS; i++) {
143 if (vgasr_priv.clients[i].pdev == pdev) {
144 vgasr_priv.registered_clients &= ~(1 << i);
149 printk(KERN_INFO "vga_switcheroo: disabled\n");
150 vga_switcheroo_debugfs_fini(&vgasr_priv);
151 vgasr_priv.active = false;
152 mutex_unlock(&vgasr_mutex);
154 EXPORT_SYMBOL(vga_switcheroo_unregister_client);
156 void vga_switcheroo_client_fb_set(struct pci_dev *pdev,
157 struct fb_info *info)
161 mutex_lock(&vgasr_mutex);
162 for (i = 0; i < VGA_SWITCHEROO_MAX_CLIENTS; i++) {
163 if (vgasr_priv.clients[i].pdev == pdev) {
164 vgasr_priv.clients[i].fb_info = info;
168 mutex_unlock(&vgasr_mutex);
170 EXPORT_SYMBOL(vga_switcheroo_client_fb_set);
172 static int vga_switcheroo_show(struct seq_file *m, void *v)
175 mutex_lock(&vgasr_mutex);
176 for (i = 0; i < VGA_SWITCHEROO_MAX_CLIENTS; i++) {
177 seq_printf(m, "%d:%s:%c:%s:%s\n", i,
178 vgasr_priv.clients[i].id == VGA_SWITCHEROO_DIS ? "DIS" : "IGD",
179 vgasr_priv.clients[i].active ? '+' : ' ',
180 vgasr_priv.clients[i].pwr_state ? "Pwr" : "Off",
181 pci_name(vgasr_priv.clients[i].pdev));
183 mutex_unlock(&vgasr_mutex);
187 static int vga_switcheroo_debugfs_open(struct inode *inode, struct file *file)
189 return single_open(file, vga_switcheroo_show, NULL);
192 static int vga_switchon(struct vga_switcheroo_client *client)
194 if (vgasr_priv.handler->power_state)
195 vgasr_priv.handler->power_state(client->id, VGA_SWITCHEROO_ON);
196 /* call the driver callback to turn on device */
197 client->set_gpu_state(client->pdev, VGA_SWITCHEROO_ON);
198 client->pwr_state = VGA_SWITCHEROO_ON;
202 static int vga_switchoff(struct vga_switcheroo_client *client)
204 /* call the driver callback to turn off device */
205 client->set_gpu_state(client->pdev, VGA_SWITCHEROO_OFF);
206 if (vgasr_priv.handler->power_state)
207 vgasr_priv.handler->power_state(client->id, VGA_SWITCHEROO_OFF);
208 client->pwr_state = VGA_SWITCHEROO_OFF;
212 static int vga_switchto(struct vga_switcheroo_client *new_client)
216 struct vga_switcheroo_client *active = NULL;
218 if (new_client->active == true)
221 for (i = 0; i < VGA_SWITCHEROO_MAX_CLIENTS; i++) {
222 if (vgasr_priv.clients[i].active == true) {
223 active = &vgasr_priv.clients[i];
230 /* power up the first device */
231 ret = pci_enable_device(new_client->pdev);
235 if (new_client->pwr_state == VGA_SWITCHEROO_OFF)
236 vga_switchon(new_client);
238 /* swap shadow resource to denote boot VGA device has changed so X starts on new device */
239 active->active = false;
241 active->pdev->resource[PCI_ROM_RESOURCE].flags &= ~IORESOURCE_ROM_SHADOW;
242 new_client->pdev->resource[PCI_ROM_RESOURCE].flags |= IORESOURCE_ROM_SHADOW;
244 if (new_client->fb_info) {
245 struct fb_event event;
246 event.info = new_client->fb_info;
247 fb_notifier_call_chain(FB_EVENT_REMAP_ALL_CONSOLE, &event);
250 ret = vgasr_priv.handler->switchto(new_client->id);
254 if (active->pwr_state == VGA_SWITCHEROO_ON)
255 vga_switchoff(active);
257 new_client->active = true;
262 vga_switcheroo_debugfs_write(struct file *filp, const char __user *ubuf,
263 size_t cnt, loff_t *ppos)
266 const char *pdev_name;
268 bool delay = false, can_switch;
269 bool just_mux = false;
271 struct vga_switcheroo_client *client = NULL;
276 if (copy_from_user(usercmd, ubuf, cnt))
279 mutex_lock(&vgasr_mutex);
281 if (!vgasr_priv.active) {
286 /* pwr off the device not in use */
287 if (strncmp(usercmd, "OFF", 3) == 0) {
288 for (i = 0; i < VGA_SWITCHEROO_MAX_CLIENTS; i++) {
289 if (vgasr_priv.clients[i].active)
291 if (vgasr_priv.clients[i].pwr_state == VGA_SWITCHEROO_ON)
292 vga_switchoff(&vgasr_priv.clients[i]);
296 /* pwr on the device not in use */
297 if (strncmp(usercmd, "ON", 2) == 0) {
298 for (i = 0; i < VGA_SWITCHEROO_MAX_CLIENTS; i++) {
299 if (vgasr_priv.clients[i].active)
301 if (vgasr_priv.clients[i].pwr_state == VGA_SWITCHEROO_OFF)
302 vga_switchon(&vgasr_priv.clients[i]);
307 /* request a delayed switch - test can we switch now */
308 if (strncmp(usercmd, "DIGD", 4) == 0) {
309 client_id = VGA_SWITCHEROO_IGD;
313 if (strncmp(usercmd, "DDIS", 4) == 0) {
314 client_id = VGA_SWITCHEROO_DIS;
318 if (strncmp(usercmd, "IGD", 3) == 0)
319 client_id = VGA_SWITCHEROO_IGD;
321 if (strncmp(usercmd, "DIS", 3) == 0)
322 client_id = VGA_SWITCHEROO_DIS;
324 if (strncmp(usercmd, "MIGD", 3) == 0) {
326 client_id = VGA_SWITCHEROO_IGD;
328 if (strncmp(usercmd, "MDIS", 3) == 0) {
330 client_id = VGA_SWITCHEROO_DIS;
336 for (i = 0; i < VGA_SWITCHEROO_MAX_CLIENTS; i++) {
337 if (vgasr_priv.clients[i].id == client_id) {
338 client = &vgasr_priv.clients[i];
343 vgasr_priv.delayed_switch_active = false;
346 ret = vgasr_priv.handler->switchto(client_id);
350 /* okay we want a switch - test if devices are willing to switch */
352 for (i = 0; i < VGA_SWITCHEROO_MAX_CLIENTS; i++) {
353 can_switch = vgasr_priv.clients[i].can_switch(vgasr_priv.clients[i].pdev);
354 if (can_switch == false) {
355 printk(KERN_ERR "vga_switcheroo: client %d refused switch\n", i);
360 if (can_switch == false && delay == false)
363 if (can_switch == true) {
364 pdev_name = pci_name(client->pdev);
365 ret = vga_switchto(client);
367 printk(KERN_ERR "vga_switcheroo: switching failed %d\n", ret);
369 printk(KERN_INFO "vga_switcheroo: setting delayed switch to client %d\n", client->id);
370 vgasr_priv.delayed_switch_active = true;
371 vgasr_priv.delayed_client_id = client_id;
373 /* we should at least power up the card to
374 make the switch faster */
375 if (client->pwr_state == VGA_SWITCHEROO_OFF)
376 vga_switchon(client);
380 mutex_unlock(&vgasr_mutex);
384 static const struct file_operations vga_switcheroo_debugfs_fops = {
385 .owner = THIS_MODULE,
386 .open = vga_switcheroo_debugfs_open,
387 .write = vga_switcheroo_debugfs_write,
390 .release = single_release,
393 static void vga_switcheroo_debugfs_fini(struct vgasr_priv *priv)
395 if (priv->switch_file) {
396 debugfs_remove(priv->switch_file);
397 priv->switch_file = NULL;
399 if (priv->debugfs_root) {
400 debugfs_remove(priv->debugfs_root);
401 priv->debugfs_root = NULL;
405 static int vga_switcheroo_debugfs_init(struct vgasr_priv *priv)
407 /* already initialised */
408 if (priv->debugfs_root)
410 priv->debugfs_root = debugfs_create_dir("vgaswitcheroo", NULL);
412 if (!priv->debugfs_root) {
413 printk(KERN_ERR "vga_switcheroo: Cannot create /sys/kernel/debug/vgaswitcheroo\n");
417 priv->switch_file = debugfs_create_file("switch", 0644,
418 priv->debugfs_root, NULL, &vga_switcheroo_debugfs_fops);
419 if (!priv->switch_file) {
420 printk(KERN_ERR "vga_switcheroo: cannot create /sys/kernel/debug/vgaswitcheroo/switch\n");
425 vga_switcheroo_debugfs_fini(priv);
429 int vga_switcheroo_process_delayed_switch(void)
431 struct vga_switcheroo_client *client = NULL;
432 const char *pdev_name;
433 bool can_switch = true;
438 mutex_lock(&vgasr_mutex);
439 if (!vgasr_priv.delayed_switch_active)
442 printk(KERN_INFO "vga_switcheroo: processing delayed switch to %d\n", vgasr_priv.delayed_client_id);
444 for (i = 0; i < VGA_SWITCHEROO_MAX_CLIENTS; i++) {
445 if (vgasr_priv.clients[i].id == vgasr_priv.delayed_client_id)
446 client = &vgasr_priv.clients[i];
447 can_switch = vgasr_priv.clients[i].can_switch(vgasr_priv.clients[i].pdev);
448 if (can_switch == false) {
449 printk(KERN_ERR "vga_switcheroo: client %d refused switch\n", i);
454 if (can_switch == false || client == NULL)
457 pdev_name = pci_name(client->pdev);
458 ret = vga_switchto(client);
460 printk(KERN_ERR "vga_switcheroo: delayed switching failed %d\n", ret);
462 vgasr_priv.delayed_switch_active = false;
465 mutex_unlock(&vgasr_mutex);
468 EXPORT_SYMBOL(vga_switcheroo_process_delayed_switch);