[deliverable/linux.git] / drivers / input / misc / xen-kbdfront.c

/*
 * Xen para-virtual input device
 *
 * Copyright (C) 2005 Anthony Liguori <aliguori@us.ibm.com>
 * Copyright (C) 2006-2008 Red Hat, Inc., Markus Armbruster <armbru@redhat.com>
 *
 *  Based on linux/drivers/input/mouse/sermouse.c
 *
 *  This file is subject to the terms and conditions of the GNU General Public
 *  License. See the file COPYING in the main directory of this archive for
 *  more details.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/module.h>
#include <linux/input.h>
#include <linux/slab.h>

#include <asm/xen/hypervisor.h>

#include <xen/xen.h>
#include <xen/events.h>
#include <xen/page.h>
#include <xen/grant_table.h>
#include <xen/interface/grant_table.h>
#include <xen/interface/io/fbif.h>
#include <xen/interface/io/kbdif.h>
#include <xen/xenbus.h>
#include <xen/platform_pci.h>

struct xenkbd_info {
	struct input_dev *kbd;
	struct input_dev *ptr;
	struct xenkbd_page *page;
	int gref;
	int irq;
	struct xenbus_device *xbdev;
	char phys[32];
};

static int xenkbd_remove(struct xenbus_device *);
static int xenkbd_connect_backend(struct xenbus_device *, struct xenkbd_info *);
static void xenkbd_disconnect_backend(struct xenkbd_info *);

/*
 * Note: if you need to send out events, see xenfb_do_update() for how
 * to do that.
 */

static irqreturn_t input_handler(int rq, void *dev_id)
{
	struct xenkbd_info *info = dev_id;
	struct xenkbd_page *page = info->page;
	__u32 cons, prod;

	prod = page->in_prod;
	if (prod == page->in_cons)
		return IRQ_HANDLED;
	rmb();			/* ensure we see ring contents up to prod */
	for (cons = page->in_cons; cons != prod; cons++) {
		union xenkbd_in_event *event;
		struct input_dev *dev;
		event = &XENKBD_IN_RING_REF(page, cons);

		dev = info->ptr;
		switch (event->type) {
		case XENKBD_TYPE_MOTION:
			input_report_rel(dev, REL_X, event->motion.rel_x);
			input_report_rel(dev, REL_Y, event->motion.rel_y);
			if (event->motion.rel_z)
				input_report_rel(dev, REL_WHEEL,
						 -event->motion.rel_z);
			break;
		case XENKBD_TYPE_KEY:
			dev = NULL;
			if (test_bit(event->key.keycode, info->kbd->keybit))
				dev = info->kbd;
			if (test_bit(event->key.keycode, info->ptr->keybit))
				dev = info->ptr;
			if (dev)
				input_report_key(dev, event->key.keycode,
						 event->key.pressed);
			else
				pr_warning("unhandled keycode 0x%x\n",
					   event->key.keycode);
			break;
		case XENKBD_TYPE_POS:
			input_report_abs(dev, ABS_X, event->pos.abs_x);
			input_report_abs(dev, ABS_Y, event->pos.abs_y);
			if (event->pos.rel_z)
				input_report_rel(dev, REL_WHEEL,
						 -event->pos.rel_z);
			break;
		}
		if (dev)
			input_sync(dev);
	}
	mb();			/* ensure we got ring contents */
	page->in_cons = cons;
	notify_remote_via_irq(info->irq);

	return IRQ_HANDLED;
}

static int xenkbd_probe(struct xenbus_device *dev,
				  const struct xenbus_device_id *id)
{
	int ret, i, abs;
	struct xenkbd_info *info;
	struct input_dev *kbd, *ptr;

	info = kzalloc(sizeof(*info), GFP_KERNEL);
	if (!info) {
		xenbus_dev_fatal(dev, -ENOMEM, "allocating info structure");
		return -ENOMEM;
	}
	dev_set_drvdata(&dev->dev, info);
	info->xbdev = dev;
	info->irq = -1;
	info->gref = -1;
	snprintf(info->phys, sizeof(info->phys), "xenbus/%s", dev->nodename);

	info->page = (void *)__get_free_page(GFP_KERNEL | __GFP_ZERO);
	if (!info->page)
		goto error_nomem;

	if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-abs-pointer", "%d", &abs) < 0)
		abs = 0;
	if (abs)
		xenbus_printf(XBT_NIL, dev->nodename, "request-abs-pointer", "1");

	/* keyboard */
	kbd = input_allocate_device();
	if (!kbd)
		goto error_nomem;
	kbd->name = "Xen Virtual Keyboard";
	kbd->phys = info->phys;
	kbd->id.bustype = BUS_PCI;
	kbd->id.vendor = 0x5853;
	kbd->id.product = 0xffff;

	__set_bit(EV_KEY, kbd->evbit);
	for (i = KEY_ESC; i < KEY_UNKNOWN; i++)
		__set_bit(i, kbd->keybit);
	for (i = KEY_OK; i < KEY_MAX; i++)
		__set_bit(i, kbd->keybit);

	ret = input_register_device(kbd);
	if (ret) {
		input_free_device(kbd);
		xenbus_dev_fatal(dev, ret, "input_register_device(kbd)");
		goto error;
	}
	info->kbd = kbd;

	/* pointing device */
	ptr = input_allocate_device();
	if (!ptr)
		goto error_nomem;
	ptr->name = "Xen Virtual Pointer";
	ptr->phys = info->phys;
	ptr->id.bustype = BUS_PCI;
	ptr->id.vendor = 0x5853;
	ptr->id.product = 0xfffe;

	if (abs) {
		__set_bit(EV_ABS, ptr->evbit);
		input_set_abs_params(ptr, ABS_X, 0, XENFB_WIDTH, 0, 0);
		input_set_abs_params(ptr, ABS_Y, 0, XENFB_HEIGHT, 0, 0);
	} else {
		input_set_capability(ptr, EV_REL, REL_X);
		input_set_capability(ptr, EV_REL, REL_Y);
	}
	input_set_capability(ptr, EV_REL, REL_WHEEL);

	__set_bit(EV_KEY, ptr->evbit);
	for (i = BTN_LEFT; i <= BTN_TASK; i++)
		__set_bit(i, ptr->keybit);

	ret = input_register_device(ptr);
	if (ret) {
		input_free_device(ptr);
		xenbus_dev_fatal(dev, ret, "input_register_device(ptr)");
		goto error;
	}
	info->ptr = ptr;

	ret = xenkbd_connect_backend(dev, info);
	if (ret < 0)
		goto error;

	return 0;

 error_nomem:
	ret = -ENOMEM;
	xenbus_dev_fatal(dev, ret, "allocating device memory");
 error:
	xenkbd_remove(dev);
	return ret;
}

static int xenkbd_resume(struct xenbus_device *dev)
{
	struct xenkbd_info *info = dev_get_drvdata(&dev->dev);

	xenkbd_disconnect_backend(info);
	memset(info->page, 0, PAGE_SIZE);
	return xenkbd_connect_backend(dev, info);
}

static int xenkbd_remove(struct xenbus_device *dev)
{
	struct xenkbd_info *info = dev_get_drvdata(&dev->dev);

	xenkbd_disconnect_backend(info);
	if (info->kbd)
		input_unregister_device(info->kbd);
	if (info->ptr)
		input_unregister_device(info->ptr);
	free_page((unsigned long)info->page);
	kfree(info);
	return 0;
}

static int xenkbd_connect_backend(struct xenbus_device *dev,
				  struct xenkbd_info *info)
{
	int ret, evtchn;
	struct xenbus_transaction xbt;

	ret = gnttab_grant_foreign_access(dev->otherend_id,
	                                  virt_to_mfn(info->page), 0);
	if (ret < 0)
		return ret;
	info->gref = ret;

	ret = xenbus_alloc_evtchn(dev, &evtchn);
	if (ret)
		goto error_grant;
	ret = bind_evtchn_to_irqhandler(evtchn, input_handler,
					0, dev->devicetype, info);
	if (ret < 0) {
		xenbus_dev_fatal(dev, ret, "bind_evtchn_to_irqhandler");
		goto error_evtchan;
	}
	info->irq = ret;

 again:
	ret = xenbus_transaction_start(&xbt);
	if (ret) {
		xenbus_dev_fatal(dev, ret, "starting transaction");
		goto error_irqh;
	}
	ret = xenbus_printf(xbt, dev->nodename, "page-ref", "%lu",
			    virt_to_mfn(info->page));
	if (ret)
		goto error_xenbus;
	ret = xenbus_printf(xbt, dev->nodename, "page-gref", "%u", info->gref);
	if (ret)
		goto error_xenbus;
	ret = xenbus_printf(xbt, dev->nodename, "event-channel", "%u",
			    evtchn);
	if (ret)
		goto error_xenbus;
	ret = xenbus_transaction_end(xbt, 0);
	if (ret) {
		if (ret == -EAGAIN)
			goto again;
		xenbus_dev_fatal(dev, ret, "completing transaction");
		goto error_irqh;
	}

	xenbus_switch_state(dev, XenbusStateInitialised);
	return 0;

 error_xenbus:
	xenbus_transaction_end(xbt, 1);
	xenbus_dev_fatal(dev, ret, "writing xenstore");
 error_irqh:
	unbind_from_irqhandler(info->irq, info);
	info->irq = -1;
 error_evtchan:
	xenbus_free_evtchn(dev, evtchn);
 error_grant:
	gnttab_end_foreign_access_ref(info->gref, 0);
	info->gref = -1;
	return ret;
}

static void xenkbd_disconnect_backend(struct xenkbd_info *info)
{
	if (info->irq >= 0)
		unbind_from_irqhandler(info->irq, info);
	info->irq = -1;
	if (info->gref >= 0)
		gnttab_end_foreign_access_ref(info->gref, 0);
	info->gref = -1;
}

static void xenkbd_backend_changed(struct xenbus_device *dev,
				   enum xenbus_state backend_state)
{
	struct xenkbd_info *info = dev_get_drvdata(&dev->dev);
	int ret, val;

	switch (backend_state) {
	case XenbusStateInitialising:
	case XenbusStateInitialised:
	case XenbusStateReconfiguring:
	case XenbusStateReconfigured:
	case XenbusStateUnknown:
		break;

	case XenbusStateInitWait:
InitWait:
		ret = xenbus_scanf(XBT_NIL, info->xbdev->otherend,
				   "feature-abs-pointer", "%d", &val);
		if (ret < 0)
			val = 0;
		if (val) {
			ret = xenbus_printf(XBT_NIL, info->xbdev->nodename,
					    "request-abs-pointer", "1");
			if (ret)
				pr_warning("xenkbd: can't request abs-pointer");
		}

		xenbus_switch_state(dev, XenbusStateConnected);
		break;

	case XenbusStateConnected:
		/*
		 * Work around xenbus race condition: If backend goes
		 * through InitWait to Connected fast enough, we can
		 * get Connected twice here.
		 */
		if (dev->state != XenbusStateConnected)
			goto InitWait; /* no InitWait seen yet, fudge it */

		/* Set input abs params to match backend screen res */
		if (xenbus_scanf(XBT_NIL, info->xbdev->otherend,
				 "width", "%d", &val) > 0)
			input_set_abs_params(info->ptr, ABS_X, 0, val, 0, 0);

		if (xenbus_scanf(XBT_NIL, info->xbdev->otherend,
				 "height", "%d", &val) > 0)
			input_set_abs_params(info->ptr, ABS_Y, 0, val, 0, 0);

		break;

	case XenbusStateClosed:
		if (dev->state == XenbusStateClosed)
			break;
		/* Missed the backend's CLOSING state -- fallthrough */
	case XenbusStateClosing:
		xenbus_frontend_closed(dev);
		break;
	}
}

static const struct xenbus_device_id xenkbd_ids[] = {
	{ "vkbd" },
	{ "" }
};

static DEFINE_XENBUS_DRIVER(xenkbd, ,
	.probe = xenkbd_probe,
	.remove = xenkbd_remove,
	.resume = xenkbd_resume,
	.otherend_changed = xenkbd_backend_changed,
);

static int __init xenkbd_init(void)
{
	if (!xen_domain())
		return -ENODEV;

	/* Nothing to do if running in dom0. */
	if (xen_initial_domain())
		return -ENODEV;

	if (!xen_has_pv_devices())
		return -ENODEV;

	return xenbus_register_frontend(&xenkbd_driver);
}

static void __exit xenkbd_cleanup(void)
{
	xenbus_unregister_driver(&xenkbd_driver);
}

module_init(xenkbd_init);
module_exit(xenkbd_cleanup);

MODULE_DESCRIPTION("Xen virtual keyboard/pointer device frontend");
MODULE_LICENSE("GPL");
MODULE_ALIAS("xen:vkbd");
Commit	Line	Data
4ee36dc0 MA	1	/*
	2	* Xen para-virtual input device
	3	*
	4	* Copyright (C) 2005 Anthony Liguori <aliguori@us.ibm.com>
	5	* Copyright (C) 2006-2008 Red Hat, Inc., Markus Armbruster <armbru@redhat.com>
	6	*
	7	* Based on linux/drivers/input/mouse/sermouse.c
	8	*
	9	* This file is subject to the terms and conditions of the GNU General Public
	10	* License. See the file COPYING in the main directory of this archive for
	11	* more details.
	12	*/
	13
da0c4901 JP	14	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
da0c4901 JP	15
4ee36dc0 MA	16	#include <linux/kernel.h>
	17	#include <linux/errno.h>
	18	#include <linux/module.h>
	19	#include <linux/input.h>
5a0e3ad6	20	#include <linux/slab.h>
1ccbf534	21
4ee36dc0	22	#include <asm/xen/hypervisor.h>
1ccbf534 JF	23
1ccbf534 JF	24	#include <xen/xen.h>
4ee36dc0 MA	25	#include <xen/events.h>
4ee36dc0 MA	26	#include <xen/page.h>
0a4dfa5d DDG	27	#include <xen/grant_table.h>
0a4dfa5d DDG	28	#include <xen/interface/grant_table.h>
4ee36dc0 MA	29	#include <xen/interface/io/fbif.h>
	30	#include <xen/interface/io/kbdif.h>
	31	#include <xen/xenbus.h>
51c71a3b	32	#include <xen/platform_pci.h>
4ee36dc0 MA	33
	34	struct xenkbd_info {
	35	struct input_dev *kbd;
	36	struct input_dev *ptr;
	37	struct xenkbd_page *page;
0a4dfa5d	38	int gref;
4ee36dc0 MA	39	int irq;
	40	struct xenbus_device *xbdev;
	41	char phys[32];
	42	};
	43
	44	static int xenkbd_remove(struct xenbus_device *);
	45	static int xenkbd_connect_backend(struct xenbus_device , struct xenkbd_info );
	46	static void xenkbd_disconnect_backend(struct xenkbd_info *);
	47
	48	/*
	49	* Note: if you need to send out events, see xenfb_do_update() for how
	50	* to do that.
	51	*/
	52
	53	static irqreturn_t input_handler(int rq, void *dev_id)
	54	{
	55	struct xenkbd_info *info = dev_id;
	56	struct xenkbd_page *page = info->page;
	57	__u32 cons, prod;
	58
	59	prod = page->in_prod;
	60	if (prod == page->in_cons)
	61	return IRQ_HANDLED;
	62	rmb(); /* ensure we see ring contents up to prod */
	63	for (cons = page->in_cons; cons != prod; cons++) {
	64	union xenkbd_in_event *event;
	65	struct input_dev *dev;
	66	event = &XENKBD_IN_RING_REF(page, cons);
	67
	68	dev = info->ptr;
	69	switch (event->type) {
	70	case XENKBD_TYPE_MOTION:
	71	input_report_rel(dev, REL_X, event->motion.rel_x);
	72	input_report_rel(dev, REL_Y, event->motion.rel_y);
6ba0e7b3 MA	73	if (event->motion.rel_z)
	74	input_report_rel(dev, REL_WHEEL,
	75	-event->motion.rel_z);
4ee36dc0 MA	76	break;
	77	case XENKBD_TYPE_KEY:
	78	dev = NULL;
	79	if (test_bit(event->key.keycode, info->kbd->keybit))
	80	dev = info->kbd;
	81	if (test_bit(event->key.keycode, info->ptr->keybit))
	82	dev = info->ptr;
	83	if (dev)
	84	input_report_key(dev, event->key.keycode,
	85	event->key.pressed);
	86	else
da0c4901 JP	87	pr_warning("unhandled keycode 0x%x\n",
da0c4901 JP	88	event->key.keycode);
4ee36dc0 MA	89	break;
	90	case XENKBD_TYPE_POS:
	91	input_report_abs(dev, ABS_X, event->pos.abs_x);
	92	input_report_abs(dev, ABS_Y, event->pos.abs_y);
6ba0e7b3 MA	93	if (event->pos.rel_z)
	94	input_report_rel(dev, REL_WHEEL,
	95	-event->pos.rel_z);
4ee36dc0 MA	96	break;
	97	}
	98	if (dev)
	99	input_sync(dev);
	100	}
	101	mb(); /* ensure we got ring contents */
	102	page->in_cons = cons;
	103	notify_remote_via_irq(info->irq);
	104
	105	return IRQ_HANDLED;
	106	}
	107
5298cc4c	108	static int xenkbd_probe(struct xenbus_device *dev,
4ee36dc0 MA	109	const struct xenbus_device_id *id)
4ee36dc0 MA	110	{
8c3c283e	111	int ret, i, abs;
4ee36dc0 MA	112	struct xenkbd_info *info;
	113	struct input_dev kbd, ptr;
	114
	115	info = kzalloc(sizeof(*info), GFP_KERNEL);
	116	if (!info) {
	117	xenbus_dev_fatal(dev, -ENOMEM, "allocating info structure");
	118	return -ENOMEM;
	119	}
1b713e00	120	dev_set_drvdata(&dev->dev, info);
4ee36dc0 MA	121	info->xbdev = dev;
4ee36dc0 MA	122	info->irq = -1;
0a4dfa5d	123	info->gref = -1;
4ee36dc0 MA	124	snprintf(info->phys, sizeof(info->phys), "xenbus/%s", dev->nodename);
	125
	126	info->page = (void *)__get_free_page(GFP_KERNEL \| __GFP_ZERO);
	127	if (!info->page)
	128	goto error_nomem;
	129
8c3c283e OH	130	if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-abs-pointer", "%d", &abs) < 0)
	131	abs = 0;
	132	if (abs)
	133	xenbus_printf(XBT_NIL, dev->nodename, "request-abs-pointer", "1");
	134
4ee36dc0 MA	135	/* keyboard */
	136	kbd = input_allocate_device();
	137	if (!kbd)
	138	goto error_nomem;
	139	kbd->name = "Xen Virtual Keyboard";
	140	kbd->phys = info->phys;
	141	kbd->id.bustype = BUS_PCI;
	142	kbd->id.vendor = 0x5853;
	143	kbd->id.product = 0xffff;
8c3c283e OH	144
8c3c283e OH	145	__set_bit(EV_KEY, kbd->evbit);
4ee36dc0	146	for (i = KEY_ESC; i < KEY_UNKNOWN; i++)
8c3c283e	147	__set_bit(i, kbd->keybit);
4ee36dc0	148	for (i = KEY_OK; i < KEY_MAX; i++)
8c3c283e	149	__set_bit(i, kbd->keybit);
4ee36dc0 MA	150
	151	ret = input_register_device(kbd);
	152	if (ret) {
	153	input_free_device(kbd);
	154	xenbus_dev_fatal(dev, ret, "input_register_device(kbd)");
	155	goto error;
	156	}
	157	info->kbd = kbd;
	158
	159	/* pointing device */
	160	ptr = input_allocate_device();
	161	if (!ptr)
	162	goto error_nomem;
	163	ptr->name = "Xen Virtual Pointer";
	164	ptr->phys = info->phys;
	165	ptr->id.bustype = BUS_PCI;
	166	ptr->id.vendor = 0x5853;
	167	ptr->id.product = 0xfffe;
8c3c283e OH	168
	169	if (abs) {
	170	__set_bit(EV_ABS, ptr->evbit);
	171	input_set_abs_params(ptr, ABS_X, 0, XENFB_WIDTH, 0, 0);
	172	input_set_abs_params(ptr, ABS_Y, 0, XENFB_HEIGHT, 0, 0);
	173	} else {
	174	input_set_capability(ptr, EV_REL, REL_X);
	175	input_set_capability(ptr, EV_REL, REL_Y);
	176	}
	177	input_set_capability(ptr, EV_REL, REL_WHEEL);
	178
	179	__set_bit(EV_KEY, ptr->evbit);
4ee36dc0	180	for (i = BTN_LEFT; i <= BTN_TASK; i++)
8c3c283e	181	__set_bit(i, ptr->keybit);
4ee36dc0 MA	182
	183	ret = input_register_device(ptr);
	184	if (ret) {
	185	input_free_device(ptr);
	186	xenbus_dev_fatal(dev, ret, "input_register_device(ptr)");
	187	goto error;
	188	}
	189	info->ptr = ptr;
	190
	191	ret = xenkbd_connect_backend(dev, info);
	192	if (ret < 0)
	193	goto error;
	194
	195	return 0;
	196
	197	error_nomem:
	198	ret = -ENOMEM;
	199	xenbus_dev_fatal(dev, ret, "allocating device memory");
	200	error:
	201	xenkbd_remove(dev);
	202	return ret;
	203	}
	204
	205	static int xenkbd_resume(struct xenbus_device *dev)
	206	{
1b713e00	207	struct xenkbd_info *info = dev_get_drvdata(&dev->dev);
4ee36dc0 MA	208
	209	xenkbd_disconnect_backend(info);
	210	memset(info->page, 0, PAGE_SIZE);
	211	return xenkbd_connect_backend(dev, info);
	212	}
	213
	214	static int xenkbd_remove(struct xenbus_device *dev)
	215	{
1b713e00	216	struct xenkbd_info *info = dev_get_drvdata(&dev->dev);
4ee36dc0 MA	217
	218	xenkbd_disconnect_backend(info);
	219	if (info->kbd)
	220	input_unregister_device(info->kbd);
	221	if (info->ptr)
	222	input_unregister_device(info->ptr);
	223	free_page((unsigned long)info->page);
	224	kfree(info);
	225	return 0;
	226	}
	227
	228	static int xenkbd_connect_backend(struct xenbus_device *dev,
	229	struct xenkbd_info *info)
	230	{
	231	int ret, evtchn;
	232	struct xenbus_transaction xbt;
	233
0a4dfa5d DDG	234	ret = gnttab_grant_foreign_access(dev->otherend_id,
	235	virt_to_mfn(info->page), 0);
	236	if (ret < 0)
	237	return ret;
	238	info->gref = ret;
	239
4ee36dc0 MA	240	ret = xenbus_alloc_evtchn(dev, &evtchn);
4ee36dc0 MA	241	if (ret)
0a4dfa5d	242	goto error_grant;
4ee36dc0 MA	243	ret = bind_evtchn_to_irqhandler(evtchn, input_handler,
	244	0, dev->devicetype, info);
	245	if (ret < 0) {
4ee36dc0	246	xenbus_dev_fatal(dev, ret, "bind_evtchn_to_irqhandler");
0a4dfa5d	247	goto error_evtchan;
4ee36dc0 MA	248	}
	249	info->irq = ret;
	250
	251	again:
	252	ret = xenbus_transaction_start(&xbt);
	253	if (ret) {
	254	xenbus_dev_fatal(dev, ret, "starting transaction");
0a4dfa5d	255	goto error_irqh;
4ee36dc0 MA	256	}
	257	ret = xenbus_printf(xbt, dev->nodename, "page-ref", "%lu",
	258	virt_to_mfn(info->page));
0a4dfa5d DDG	259	if (ret)
	260	goto error_xenbus;
	261	ret = xenbus_printf(xbt, dev->nodename, "page-gref", "%u", info->gref);
4ee36dc0 MA	262	if (ret)
	263	goto error_xenbus;
	264	ret = xenbus_printf(xbt, dev->nodename, "event-channel", "%u",
	265	evtchn);
	266	if (ret)
	267	goto error_xenbus;
	268	ret = xenbus_transaction_end(xbt, 0);
	269	if (ret) {
	270	if (ret == -EAGAIN)
	271	goto again;
	272	xenbus_dev_fatal(dev, ret, "completing transaction");
0a4dfa5d	273	goto error_irqh;
4ee36dc0 MA	274	}
	275
	276	xenbus_switch_state(dev, XenbusStateInitialised);
	277	return 0;
	278
	279	error_xenbus:
	280	xenbus_transaction_end(xbt, 1);
	281	xenbus_dev_fatal(dev, ret, "writing xenstore");
0a4dfa5d DDG	282	error_irqh:
	283	unbind_from_irqhandler(info->irq, info);
	284	info->irq = -1;
	285	error_evtchan:
	286	xenbus_free_evtchn(dev, evtchn);
	287	error_grant:
	288	gnttab_end_foreign_access_ref(info->gref, 0);
	289	info->gref = -1;
4ee36dc0 MA	290	return ret;
	291	}
	292
	293	static void xenkbd_disconnect_backend(struct xenkbd_info *info)
	294	{
	295	if (info->irq >= 0)
	296	unbind_from_irqhandler(info->irq, info);
	297	info->irq = -1;
0a4dfa5d DDG	298	if (info->gref >= 0)
	299	gnttab_end_foreign_access_ref(info->gref, 0);
	300	info->gref = -1;
4ee36dc0 MA	301	}
	302
	303	static void xenkbd_backend_changed(struct xenbus_device *dev,
	304	enum xenbus_state backend_state)
	305	{
1b713e00	306	struct xenkbd_info *info = dev_get_drvdata(&dev->dev);
c36b58e8	307	int ret, val;
4ee36dc0 MA	308
	309	switch (backend_state) {
	310	case XenbusStateInitialising:
	311	case XenbusStateInitialised:
b78c9512 NI	312	case XenbusStateReconfiguring:
b78c9512 NI	313	case XenbusStateReconfigured:
4ee36dc0	314	case XenbusStateUnknown:
4ee36dc0 MA	315	break;
	316
	317	case XenbusStateInitWait:
	318	InitWait:
c36b58e8 IM	319	ret = xenbus_scanf(XBT_NIL, info->xbdev->otherend,
	320	"feature-abs-pointer", "%d", &val);
	321	if (ret < 0)
	322	val = 0;
	323	if (val) {
	324	ret = xenbus_printf(XBT_NIL, info->xbdev->nodename,
	325	"request-abs-pointer", "1");
	326	if (ret)
	327	pr_warning("xenkbd: can't request abs-pointer");
	328	}
	329
4ee36dc0 MA	330	xenbus_switch_state(dev, XenbusStateConnected);
	331	break;
	332
	333	case XenbusStateConnected:
	334	/*
	335	* Work around xenbus race condition: If backend goes
	336	* through InitWait to Connected fast enough, we can
	337	* get Connected twice here.
	338	*/
	339	if (dev->state != XenbusStateConnected)
	340	goto InitWait; /* no InitWait seen yet, fudge it */
e4dcff1f MA	341
	342	/* Set input abs params to match backend screen res */
	343	if (xenbus_scanf(XBT_NIL, info->xbdev->otherend,
	344	"width", "%d", &val) > 0)
	345	input_set_abs_params(info->ptr, ABS_X, 0, val, 0, 0);
	346
	347	if (xenbus_scanf(XBT_NIL, info->xbdev->otherend,
	348	"height", "%d", &val) > 0)
	349	input_set_abs_params(info->ptr, ABS_Y, 0, val, 0, 0);
	350
4ee36dc0 MA	351	break;
4ee36dc0 MA	352
2ebb939a DV	353	case XenbusStateClosed:
	354	if (dev->state == XenbusStateClosed)
	355	break;
	356	/* Missed the backend's CLOSING state -- fallthrough */
4ee36dc0 MA	357	case XenbusStateClosing:
	358	xenbus_frontend_closed(dev);
	359	break;
	360	}
	361	}
	362
c6d57093	363	static const struct xenbus_device_id xenkbd_ids[] = {
4ee36dc0 MA	364	{ "vkbd" },
	365	{ "" }
	366	};
	367
73db144b	368	static DEFINE_XENBUS_DRIVER(xenkbd, ,
4ee36dc0 MA	369	.probe = xenkbd_probe,
	370	.remove = xenkbd_remove,
	371	.resume = xenkbd_resume,
	372	.otherend_changed = xenkbd_backend_changed,
73db144b	373	);
4ee36dc0 MA	374
	375	static int __init xenkbd_init(void)
	376	{
5f098ecd	377	if (!xen_domain())
4ee36dc0 MA	378	return -ENODEV;
	379
	380	/* Nothing to do if running in dom0. */
6e833587	381	if (xen_initial_domain())
4ee36dc0 MA	382	return -ENODEV;
4ee36dc0 MA	383
51c71a3b KRW	384	if (!xen_has_pv_devices())
	385	return -ENODEV;
	386
ffb78a26	387	return xenbus_register_frontend(&xenkbd_driver);
4ee36dc0 MA	388	}
	389
	390	static void __exit xenkbd_cleanup(void)
	391	{
ffb78a26	392	xenbus_unregister_driver(&xenkbd_driver);
4ee36dc0 MA	393	}
	394
	395	module_init(xenkbd_init);
	396	module_exit(xenkbd_cleanup);
	397
1e892c95	398	MODULE_DESCRIPTION("Xen virtual keyboard/pointer device frontend");
4ee36dc0	399	MODULE_LICENSE("GPL");
1e892c95	400	MODULE_ALIAS("xen:vkbd");