[net-next-2.6.git] / drivers / gpu / vga / vga_switcheroo.c

/*
 * Copyright (c) 2010 Red Hat Inc.
 * Author : Dave Airlie <airlied@redhat.com>
 *
 *
 * Licensed under GPLv2
 *
 * vga_switcheroo.c - Support for laptop with dual GPU using one set of outputs

 Switcher interface - methods require for ATPX and DCM
 - switchto - this throws the output MUX switch
 - discrete_set_power - sets the power state for the discrete card

 GPU driver interface
 - set_gpu_state - this should do the equiv of s/r for the card
		  - this should *not* set the discrete power state
 - switch_check  - check if the device is in a position to switch now
 */

#include <linux/module.h>
#include <linux/dmi.h>
#include <linux/seq_file.h>
#include <linux/uaccess.h>
#include <linux/fs.h>
#include <linux/debugfs.h>
#include <linux/fb.h>

#include <linux/pci.h>
#include <linux/vga_switcheroo.h>

struct vga_switcheroo_client {
	struct pci_dev *pdev;
	struct fb_info *fb_info;
	int pwr_state;
	void (*set_gpu_state)(struct pci_dev *pdev, enum vga_switcheroo_state);
	bool (*can_switch)(struct pci_dev *pdev);
	int id;
	bool active;
};

static DEFINE_MUTEX(vgasr_mutex);

struct vgasr_priv {

	bool active;
	bool delayed_switch_active;
	enum vga_switcheroo_client_id delayed_client_id;

	struct dentry *debugfs_root;
	struct dentry *switch_file;

	int registered_clients;
	struct vga_switcheroo_client clients[VGA_SWITCHEROO_MAX_CLIENTS];

	struct vga_switcheroo_handler *handler;
};

static int vga_switcheroo_debugfs_init(struct vgasr_priv *priv);
static void vga_switcheroo_debugfs_fini(struct vgasr_priv *priv);

/* only one switcheroo per system */
static struct vgasr_priv vgasr_priv;

int vga_switcheroo_register_handler(struct vga_switcheroo_handler *handler)
{
	mutex_lock(&vgasr_mutex);
	if (vgasr_priv.handler) {
		mutex_unlock(&vgasr_mutex);
		return -EINVAL;
	}

	vgasr_priv.handler = handler;
	mutex_unlock(&vgasr_mutex);
	return 0;
}
EXPORT_SYMBOL(vga_switcheroo_register_handler);

void vga_switcheroo_unregister_handler(void)
{
	mutex_lock(&vgasr_mutex);
	vgasr_priv.handler = NULL;
	mutex_unlock(&vgasr_mutex);
}
EXPORT_SYMBOL(vga_switcheroo_unregister_handler);

static void vga_switcheroo_enable(void)
{
	int i;
	int ret;
	/* call the handler to init */
	vgasr_priv.handler->init();

	for (i = 0; i < VGA_SWITCHEROO_MAX_CLIENTS; i++) {
		ret = vgasr_priv.handler->get_client_id(vgasr_priv.clients[i].pdev);
		if (ret < 0)
			return;

		vgasr_priv.clients[i].id = ret;
	}
	vga_switcheroo_debugfs_init(&vgasr_priv);
	vgasr_priv.active = true;
}

int vga_switcheroo_register_client(struct pci_dev *pdev,
				   void (*set_gpu_state)(struct pci_dev *pdev, enum vga_switcheroo_state),
				   bool (*can_switch)(struct pci_dev *pdev))
{
	int index;

	mutex_lock(&vgasr_mutex);
	/* don't do IGD vs DIS here */
	if (vgasr_priv.registered_clients & 1)
		index = 1;
	else
		index = 0;

	vgasr_priv.clients[index].pwr_state = VGA_SWITCHEROO_ON;
	vgasr_priv.clients[index].pdev = pdev;
	vgasr_priv.clients[index].set_gpu_state = set_gpu_state;
	vgasr_priv.clients[index].can_switch = can_switch;
	vgasr_priv.clients[index].id = -1;
	if (pdev->resource[PCI_ROM_RESOURCE].flags & IORESOURCE_ROM_SHADOW)
		vgasr_priv.clients[index].active = true;

	vgasr_priv.registered_clients |= (1 << index);

	/* if we get two clients + handler */
	if (vgasr_priv.registered_clients == 0x3 && vgasr_priv.handler) {
		printk(KERN_INFO "vga_switcheroo: enabled\n");
		vga_switcheroo_enable();
	}
	mutex_unlock(&vgasr_mutex);
	return 0;
}
EXPORT_SYMBOL(vga_switcheroo_register_client);

void vga_switcheroo_unregister_client(struct pci_dev *pdev)
{
	int i;

	mutex_lock(&vgasr_mutex);
	for (i = 0; i < VGA_SWITCHEROO_MAX_CLIENTS; i++) {
		if (vgasr_priv.clients[i].pdev == pdev) {
			vgasr_priv.registered_clients &= ~(1 << i);
			break;
		}
	}

	printk(KERN_INFO "vga_switcheroo: disabled\n");
	vga_switcheroo_debugfs_fini(&vgasr_priv);
	vgasr_priv.active = false;
	mutex_unlock(&vgasr_mutex);
}
EXPORT_SYMBOL(vga_switcheroo_unregister_client);

void vga_switcheroo_client_fb_set(struct pci_dev *pdev,
				 struct fb_info *info)
{
	int i;

	mutex_lock(&vgasr_mutex);
	for (i = 0; i < VGA_SWITCHEROO_MAX_CLIENTS; i++) {
		if (vgasr_priv.clients[i].pdev == pdev) {
			vgasr_priv.clients[i].fb_info = info;
			break;
		}
	}
	mutex_unlock(&vgasr_mutex);
}
EXPORT_SYMBOL(vga_switcheroo_client_fb_set);

static int vga_switcheroo_show(struct seq_file *m, void *v)
{
	int i;
	mutex_lock(&vgasr_mutex);
	for (i = 0; i < VGA_SWITCHEROO_MAX_CLIENTS; i++) {
		seq_printf(m, "%d:%c:%s:%s\n", i,
			   vgasr_priv.clients[i].active ? '+' : ' ',
			   vgasr_priv.clients[i].pwr_state ? "Pwr" : "Off",
			   pci_name(vgasr_priv.clients[i].pdev));
	}
	mutex_unlock(&vgasr_mutex);
	return 0;
}

static int vga_switcheroo_debugfs_open(struct inode *inode, struct file *file)
{
	return single_open(file, vga_switcheroo_show, NULL);
}

static int vga_switchon(struct vga_switcheroo_client *client)
{
	int ret;

	ret = vgasr_priv.handler->power_state(client->id, VGA_SWITCHEROO_ON);
	/* call the driver callback to turn on device */
	client->set_gpu_state(client->pdev, VGA_SWITCHEROO_ON);
	client->pwr_state = VGA_SWITCHEROO_ON;
	return 0;
}

static int vga_switchoff(struct vga_switcheroo_client *client)
{
	/* call the driver callback to turn off device */
	client->set_gpu_state(client->pdev, VGA_SWITCHEROO_OFF);
	vgasr_priv.handler->power_state(client->id, VGA_SWITCHEROO_OFF);
	client->pwr_state = VGA_SWITCHEROO_OFF;
	return 0;
}

static int vga_switchto(struct vga_switcheroo_client *new_client)
{
	int ret;
	int i;
	struct vga_switcheroo_client *active = NULL;

	if (new_client->active == true)
		return 0;

	for (i = 0; i < VGA_SWITCHEROO_MAX_CLIENTS; i++) {
		if (vgasr_priv.clients[i].active == true) {
			active = &vgasr_priv.clients[i];
			break;
		}
	}
	if (!active)
		return 0;

	/* power up the first device */
	ret = pci_enable_device(new_client->pdev);
	if (ret)
		return ret;

	if (new_client->pwr_state == VGA_SWITCHEROO_OFF)
		vga_switchon(new_client);

	/* swap shadow resource to denote boot VGA device has changed so X starts on new device */
	active->active = false;

	active->pdev->resource[PCI_ROM_RESOURCE].flags &= ~IORESOURCE_ROM_SHADOW;
	new_client->pdev->resource[PCI_ROM_RESOURCE].flags |= IORESOURCE_ROM_SHADOW;

	if (new_client->fb_info) {
		struct fb_event event;
		event.info = new_client->fb_info;
		fb_notifier_call_chain(FB_EVENT_REMAP_ALL_CONSOLE, &event);
	}

	ret = vgasr_priv.handler->switchto(new_client->id);
	if (ret)
		return ret;

	if (active->pwr_state == VGA_SWITCHEROO_ON)
		vga_switchoff(active);

	new_client->active = true;
	return 0;
}

static ssize_t
vga_switcheroo_debugfs_write(struct file *filp, const char __user *ubuf,
			     size_t cnt, loff_t *ppos)
{
	char usercmd[64];
	const char *pdev_name;
	int i, ret;
	bool delay = false, can_switch;
	int client_id = -1;
	struct vga_switcheroo_client *client = NULL;

	if (cnt > 63)
		cnt = 63;

	if (copy_from_user(usercmd, ubuf, cnt))
		return -EFAULT;

	mutex_lock(&vgasr_mutex);

	if (!vgasr_priv.active)
		return -EINVAL;

	/* pwr off the device not in use */
	if (strncmp(usercmd, "OFF", 3) == 0) {
		for (i = 0; i < VGA_SWITCHEROO_MAX_CLIENTS; i++) {
			if (vgasr_priv.clients[i].active)
				continue;
			if (vgasr_priv.clients[i].pwr_state == VGA_SWITCHEROO_ON)
				vga_switchoff(&vgasr_priv.clients[i]);
		}
		goto out;
	}
	/* pwr on the device not in use */
	if (strncmp(usercmd, "ON", 2) == 0) {
		for (i = 0; i < VGA_SWITCHEROO_MAX_CLIENTS; i++) {
			if (vgasr_priv.clients[i].active)
				continue;
			if (vgasr_priv.clients[i].pwr_state == VGA_SWITCHEROO_OFF)
				vga_switchon(&vgasr_priv.clients[i]);
		}
		goto out;
	}

	/* request a delayed switch - test can we switch now */
	if (strncmp(usercmd, "DIGD", 4) == 0) {
		client_id = VGA_SWITCHEROO_IGD;
		delay = true;
	}

	if (strncmp(usercmd, "DDIS", 4) == 0) {
		client_id = VGA_SWITCHEROO_DIS;
		delay = true;
	}

	if (strncmp(usercmd, "IGD", 3) == 0)
		client_id = VGA_SWITCHEROO_IGD;

	if (strncmp(usercmd, "DIS", 3) == 0)
		client_id = VGA_SWITCHEROO_DIS;

	if (client_id == -1)
		goto out;

	for (i = 0; i < VGA_SWITCHEROO_MAX_CLIENTS; i++) {
		if (vgasr_priv.clients[i].id == client_id) {
			client = &vgasr_priv.clients[i];
			break;
		}
	}

	vgasr_priv.delayed_switch_active = false;
	/* okay we want a switch - test if devices are willing to switch */
	can_switch = true;
	for (i = 0; i < VGA_SWITCHEROO_MAX_CLIENTS; i++) {
		can_switch = vgasr_priv.clients[i].can_switch(vgasr_priv.clients[i].pdev);
		if (can_switch == false) {
			printk(KERN_ERR "vga_switcheroo: client %d refused switch\n", i);
			break;
		}
	}

	if (can_switch == false && delay == false)
		goto out;

	if (can_switch == true) {
		pdev_name = pci_name(client->pdev);
		ret = vga_switchto(client);
		if (ret)
			printk(KERN_ERR "vga_switcheroo: switching failed %d\n", ret);
	} else {
		printk(KERN_INFO "vga_switcheroo: setting delayed switch to client %d\n", client->id);
		vgasr_priv.delayed_switch_active = true;
		vgasr_priv.delayed_client_id = client_id;

		/* we should at least power up the card to
		   make the switch faster */
		if (client->pwr_state == VGA_SWITCHEROO_OFF)
			vga_switchon(client);
	}

out:
	mutex_unlock(&vgasr_mutex);
	return cnt;
}

static const struct file_operations vga_switcheroo_debugfs_fops = {
	.owner = THIS_MODULE,
	.open = vga_switcheroo_debugfs_open,
	.write = vga_switcheroo_debugfs_write,
	.read = seq_read,
	.llseek = seq_lseek,
	.release = single_release,
};

static void vga_switcheroo_debugfs_fini(struct vgasr_priv *priv)
{
	if (priv->switch_file) {
		debugfs_remove(priv->switch_file);
		priv->switch_file = NULL;
	}
	if (priv->debugfs_root) {
		debugfs_remove(priv->debugfs_root);
		priv->debugfs_root = NULL;
	}
}

static int vga_switcheroo_debugfs_init(struct vgasr_priv *priv)
{
	/* already initialised */
	if (priv->debugfs_root)
		return 0;
	priv->debugfs_root = debugfs_create_dir("vgaswitcheroo", NULL);

	if (!priv->debugfs_root) {
		printk(KERN_ERR "vga_switcheroo: Cannot create /sys/kernel/debug/vgaswitcheroo\n");
		goto fail;
	}

	priv->switch_file = debugfs_create_file("switch", 0644,
						priv->debugfs_root, NULL, &vga_switcheroo_debugfs_fops);
	if (!priv->switch_file) {
		printk(KERN_ERR "vga_switcheroo: cannot create /sys/kernel/debug/vgaswitcheroo/switch\n");
		goto fail;
	}
	return 0;
fail:
	vga_switcheroo_debugfs_fini(priv);
	return -1;
}

int vga_switcheroo_process_delayed_switch(void)
{
	struct vga_switcheroo_client *client = NULL;
	const char *pdev_name;
	bool can_switch = true;
	int i;
	int ret;
	int err = -EINVAL;

	mutex_lock(&vgasr_mutex);
	if (!vgasr_priv.delayed_switch_active)
		goto err;

	printk(KERN_INFO "vga_switcheroo: processing delayed switch to %d\n", vgasr_priv.delayed_client_id);

	for (i = 0; i < VGA_SWITCHEROO_MAX_CLIENTS; i++) {
		if (vgasr_priv.clients[i].id == vgasr_priv.delayed_client_id)
			client = &vgasr_priv.clients[i];
		can_switch = vgasr_priv.clients[i].can_switch(vgasr_priv.clients[i].pdev);
		if (can_switch == false) {
			printk(KERN_ERR "vga_switcheroo: client %d refused switch\n", i);
			break;
		}
	}

	if (can_switch == false || client == NULL)
		goto err;

	pdev_name = pci_name(client->pdev);
	ret = vga_switchto(client);
	if (ret)
		printk(KERN_ERR "vga_switcheroo: delayed switching failed %d\n", ret);

	vgasr_priv.delayed_switch_active = false;
	err = 0;
err:
	mutex_unlock(&vgasr_mutex);
	return err;
}
EXPORT_SYMBOL(vga_switcheroo_process_delayed_switch);
Commit	Line	Data
6a9ee8af DA	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
6a9ee8af DA	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	bool (can_switch)(struct pci_dev pdev);
	37	int id;
	38	bool active;
	39	};
	40
	41	static DEFINE_MUTEX(vgasr_mutex);
	42
	43	struct vgasr_priv {
	44
	45	bool active;
	46	bool delayed_switch_active;
	47	enum vga_switcheroo_client_id delayed_client_id;
	48
	49	struct dentry *debugfs_root;
	50	struct dentry *switch_file;
	51
	52	int registered_clients;
	53	struct vga_switcheroo_client clients[VGA_SWITCHEROO_MAX_CLIENTS];
	54
	55	struct vga_switcheroo_handler *handler;
	56	};
	57
	58	static int vga_switcheroo_debugfs_init(struct vgasr_priv *priv);
	59	static void vga_switcheroo_debugfs_fini(struct vgasr_priv *priv);
	60
	61	/* only one switcheroo per system */
	62	static struct vgasr_priv vgasr_priv;
	63
	64	int vga_switcheroo_register_handler(struct vga_switcheroo_handler *handler)
	65	{
	66	mutex_lock(&vgasr_mutex);
	67	if (vgasr_priv.handler) {
	68	mutex_unlock(&vgasr_mutex);
	69	return -EINVAL;
	70	}
	71
	72	vgasr_priv.handler = handler;
	73	mutex_unlock(&vgasr_mutex);
	74	return 0;
	75	}
	76	EXPORT_SYMBOL(vga_switcheroo_register_handler);
	77
	78	void vga_switcheroo_unregister_handler(void)
	79	{
	80	mutex_lock(&vgasr_mutex);
	81	vgasr_priv.handler = NULL;
	82	mutex_unlock(&vgasr_mutex);
	83	}
	84	EXPORT_SYMBOL(vga_switcheroo_unregister_handler);
	85
	86	static void vga_switcheroo_enable(void)
	87	{
	88	int i;
	89	int ret;
	90	/* call the handler to init */
	91	vgasr_priv.handler->init();
92
93	for (i = 0; i < VGA_SWITCHEROO_MAX_CLIENTS; i++) {
94	ret = vgasr_priv.handler->get_client_id(vgasr_priv.clients[i].pdev);
95	if (ret < 0)
96	return;
97
98	vgasr_priv.clients[i].id = ret;
99	}
100	vga_switcheroo_debugfs_init(&vgasr_priv);
101	vgasr_priv.active = true;
102	}
103
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))
107	{
108	int index;
109
110	mutex_lock(&vgasr_mutex);
111	/* don't do IGD vs DIS here */
112	if (vgasr_priv.registered_clients & 1)
113	index = 1;
114	else
115	index = 0;
116
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;
124
125	vgasr_priv.registered_clients \|= (1 << index);
126
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();
131	}
132	mutex_unlock(&vgasr_mutex);
133	return 0;
134	}
135	EXPORT_SYMBOL(vga_switcheroo_register_client);
136
137	void vga_switcheroo_unregister_client(struct pci_dev *pdev)
138	{
139	int i;
140
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);
145	break;
146	}
147	}
148
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);
153	}
154	EXPORT_SYMBOL(vga_switcheroo_unregister_client);
155
156	void vga_switcheroo_client_fb_set(struct pci_dev *pdev,
157	struct fb_info *info)
158	{
159	int i;
160
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;
165	break;
166	}
167	}
168	mutex_unlock(&vgasr_mutex);
169	}
170	EXPORT_SYMBOL(vga_switcheroo_client_fb_set);
171
172	static int vga_switcheroo_show(struct seq_file m, void v)
173	{
174	int i;
175	mutex_lock(&vgasr_mutex);
176	for (i = 0; i < VGA_SWITCHEROO_MAX_CLIENTS; i++) {
177	seq_printf(m, "%d:%c:%s:%s\n", i,
178	vgasr_priv.clients[i].active ? '+' : ' ',
179	vgasr_priv.clients[i].pwr_state ? "Pwr" : "Off",
180	pci_name(vgasr_priv.clients[i].pdev));
181	}
182	mutex_unlock(&vgasr_mutex);
183	return 0;
184	}
185
186	static int vga_switcheroo_debugfs_open(struct inode inode, struct file file)
187	{
188	return single_open(file, vga_switcheroo_show, NULL);
189	}
190
191	static int vga_switchon(struct vga_switcheroo_client *client)
192	{
193	int ret;
194
195	ret = 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;
199	return 0;
200	}
201
202	static int vga_switchoff(struct vga_switcheroo_client *client)
203	{
204	/* call the driver callback to turn off device */
205	client->set_gpu_state(client->pdev, VGA_SWITCHEROO_OFF);
206	vgasr_priv.handler->power_state(client->id, VGA_SWITCHEROO_OFF);
207	client->pwr_state = VGA_SWITCHEROO_OFF;
208	return 0;
209	}
210
211	static int vga_switchto(struct vga_switcheroo_client *new_client)
212	{
213	int ret;
214	int i;
215	struct vga_switcheroo_client *active = NULL;
216
217	if (new_client->active == true)
218	return 0;
219
220	for (i = 0; i < VGA_SWITCHEROO_MAX_CLIENTS; i++) {
221	if (vgasr_priv.clients[i].active == true) {
222	active = &vgasr_priv.clients[i];
223	break;
224	}
225	}
226	if (!active)
227	return 0;
228
229	/* power up the first device */
230	ret = pci_enable_device(new_client->pdev);
231	if (ret)
232	return ret;
233
234	if (new_client->pwr_state == VGA_SWITCHEROO_OFF)
235	vga_switchon(new_client);
236
237	/* swap shadow resource to denote boot VGA device has changed so X starts on new device */
238	active->active = false;
239
240	active->pdev->resource[PCI_ROM_RESOURCE].flags &= ~IORESOURCE_ROM_SHADOW;
241	new_client->pdev->resource[PCI_ROM_RESOURCE].flags \|= IORESOURCE_ROM_SHADOW;
242
243	if (new_client->fb_info) {
244	struct fb_event event;
245	event.info = new_client->fb_info;
246	fb_notifier_call_chain(FB_EVENT_REMAP_ALL_CONSOLE, &event);
247	}
248
249	ret = vgasr_priv.handler->switchto(new_client->id);
250	if (ret)
251	return ret;
252
253	if (active->pwr_state == VGA_SWITCHEROO_ON)
254	vga_switchoff(active);
255
256	new_client->active = true;
257	return 0;
258	}
259
260	static ssize_t
261	vga_switcheroo_debugfs_write(struct file filp, const char __user ubuf,
262	size_t cnt, loff_t *ppos)
263	{
264	char usercmd[64];
265	const char *pdev_name;
266	int i, ret;
267	bool delay = false, can_switch;
268	int client_id = -1;
269	struct vga_switcheroo_client *client = NULL;
270
271	if (cnt > 63)
272	cnt = 63;
273
274	if (copy_from_user(usercmd, ubuf, cnt))
275	return -EFAULT;
276
277	mutex_lock(&vgasr_mutex);
278
279	if (!vgasr_priv.active)
280	return -EINVAL;
281
282	/* pwr off the device not in use */
283	if (strncmp(usercmd, "OFF", 3) == 0) {
284	for (i = 0; i < VGA_SWITCHEROO_MAX_CLIENTS; i++) {
285	if (vgasr_priv.clients[i].active)
286	continue;
287	if (vgasr_priv.clients[i].pwr_state == VGA_SWITCHEROO_ON)
288	vga_switchoff(&vgasr_priv.clients[i]);
289	}
290	goto out;
291	}
292	/* pwr on the device not in use */
293	if (strncmp(usercmd, "ON", 2) == 0) {
294	for (i = 0; i < VGA_SWITCHEROO_MAX_CLIENTS; i++) {
295	if (vgasr_priv.clients[i].active)
296	continue;
297	if (vgasr_priv.clients[i].pwr_state == VGA_SWITCHEROO_OFF)
298	vga_switchon(&vgasr_priv.clients[i]);
299	}
300	goto out;
301	}
302
303	/* request a delayed switch - test can we switch now */
304	if (strncmp(usercmd, "DIGD", 4) == 0) {
305	client_id = VGA_SWITCHEROO_IGD;
306	delay = true;
307	}
308
309	if (strncmp(usercmd, "DDIS", 4) == 0) {
310	client_id = VGA_SWITCHEROO_DIS;
311	delay = true;
312	}
313
314	if (strncmp(usercmd, "IGD", 3) == 0)
315	client_id = VGA_SWITCHEROO_IGD;
316
317	if (strncmp(usercmd, "DIS", 3) == 0)
318	client_id = VGA_SWITCHEROO_DIS;
319
320	if (client_id == -1)
321	goto out;
322
323	for (i = 0; i < VGA_SWITCHEROO_MAX_CLIENTS; i++) {
324	if (vgasr_priv.clients[i].id == client_id) {
325	client = &vgasr_priv.clients[i];
326	break;
327	}
328	}
329
330	vgasr_priv.delayed_switch_active = false;
331	/* okay we want a switch - test if devices are willing to switch */
332	can_switch = true;
333	for (i = 0; i < VGA_SWITCHEROO_MAX_CLIENTS; i++) {
334	can_switch = vgasr_priv.clients[i].can_switch(vgasr_priv.clients[i].pdev);
335	if (can_switch == false) {
336	printk(KERN_ERR "vga_switcheroo: client %d refused switch\n", i);
337	break;
338	}
339	}
340
341	if (can_switch == false && delay == false)
342	goto out;
343
344	if (can_switch == true) {
345	pdev_name = pci_name(client->pdev);
346	ret = vga_switchto(client);
347	if (ret)
348	printk(KERN_ERR "vga_switcheroo: switching failed %d\n", ret);
349	} else {
350	printk(KERN_INFO "vga_switcheroo: setting delayed switch to client %d\n", client->id);
351	vgasr_priv.delayed_switch_active = true;
352	vgasr_priv.delayed_client_id = client_id;
353
354	/* we should at least power up the card to
355	make the switch faster */
356	if (client->pwr_state == VGA_SWITCHEROO_OFF)
357	vga_switchon(client);
358	}
359
360	out:
361	mutex_unlock(&vgasr_mutex);
362	return cnt;
363	}
364
365	static const struct file_operations vga_switcheroo_debugfs_fops = {
366	.owner = THIS_MODULE,
367	.open = vga_switcheroo_debugfs_open,
368	.write = vga_switcheroo_debugfs_write,
369	.read = seq_read,
370	.llseek = seq_lseek,
371	.release = single_release,
372	};
373
374	static void vga_switcheroo_debugfs_fini(struct vgasr_priv *priv)
375	{
376	if (priv->switch_file) {
377	debugfs_remove(priv->switch_file);
378	priv->switch_file = NULL;
379	}
380	if (priv->debugfs_root) {
381	debugfs_remove(priv->debugfs_root);
382	priv->debugfs_root = NULL;
383	}
384	}
385
386	static int vga_switcheroo_debugfs_init(struct vgasr_priv *priv)
387	{
388	/* already initialised */
389	if (priv->debugfs_root)
390	return 0;
391	priv->debugfs_root = debugfs_create_dir("vgaswitcheroo", NULL);
392
393	if (!priv->debugfs_root) {
394	printk(KERN_ERR "vga_switcheroo: Cannot create /sys/kernel/debug/vgaswitcheroo\n");
395	goto fail;
396	}
397
398	priv->switch_file = debugfs_create_file("switch", 0644,
399	priv->debugfs_root, NULL, &vga_switcheroo_debugfs_fops);
400	if (!priv->switch_file) {
401	printk(KERN_ERR "vga_switcheroo: cannot create /sys/kernel/debug/vgaswitcheroo/switch\n");
402	goto fail;
403	}
404	return 0;
405	fail:
406	vga_switcheroo_debugfs_fini(priv);
407	return -1;
408	}
409
410	int vga_switcheroo_process_delayed_switch(void)
411	{
412	struct vga_switcheroo_client *client = NULL;
413	const char *pdev_name;
414	bool can_switch = true;
415	int i;
416	int ret;
417	int err = -EINVAL;
418
419	mutex_lock(&vgasr_mutex);
420	if (!vgasr_priv.delayed_switch_active)
421	goto err;
422
423	printk(KERN_INFO "vga_switcheroo: processing delayed switch to %d\n", vgasr_priv.delayed_client_id);
424
425	for (i = 0; i < VGA_SWITCHEROO_MAX_CLIENTS; i++) {
426	if (vgasr_priv.clients[i].id == vgasr_priv.delayed_client_id)
427	client = &vgasr_priv.clients[i];
428	can_switch = vgasr_priv.clients[i].can_switch(vgasr_priv.clients[i].pdev);
429	if (can_switch == false) {
430	printk(KERN_ERR "vga_switcheroo: client %d refused switch\n", i);
431	break;
432	}
433	}
434
435	if (can_switch == false \|\| client == NULL)
436	goto err;
437
438	pdev_name = pci_name(client->pdev);
439	ret = vga_switchto(client);
440	if (ret)
441	printk(KERN_ERR "vga_switcheroo: delayed switching failed %d\n", ret);
442
443	vgasr_priv.delayed_switch_active = false;
444	err = 0;
445	err:
446	mutex_unlock(&vgasr_mutex);
447	return err;
448	}
449	EXPORT_SYMBOL(vga_switcheroo_process_delayed_switch);
450