[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) {
		ret = xenbus_printf(XBT_NIL, dev->nodename,
				    "request-abs-pointer", "1");
		if (ret) {
			pr_warning("xenkbd: can't request abs-pointer");
			abs = 0;
		}
	}

	/* 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_gfn(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_gfn(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(info->gref, 0, 0UL);
	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(info->gref, 0, 0UL);
	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 struct xenbus_driver xenkbd_driver = {
	.ids = xenkbd_ids,
	.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)
8c3c283e OH	131	abs = 0;
ec7aa963 IY	132	if (abs) {
	133	ret = xenbus_printf(XBT_NIL, dev->nodename,
	134	"request-abs-pointer", "1");
	135	if (ret) {
	136	pr_warning("xenkbd: can't request abs-pointer");
	137	abs = 0;
	138	}
	139	}
8c3c283e	140
4ee36dc0 MA	141	/* keyboard */
	142	kbd = input_allocate_device();
	143	if (!kbd)
	144	goto error_nomem;
	145	kbd->name = "Xen Virtual Keyboard";
	146	kbd->phys = info->phys;
	147	kbd->id.bustype = BUS_PCI;
	148	kbd->id.vendor = 0x5853;
	149	kbd->id.product = 0xffff;
8c3c283e OH	150
8c3c283e OH	151	__set_bit(EV_KEY, kbd->evbit);
4ee36dc0	152	for (i = KEY_ESC; i < KEY_UNKNOWN; i++)
8c3c283e	153	__set_bit(i, kbd->keybit);
4ee36dc0	154	for (i = KEY_OK; i < KEY_MAX; i++)
8c3c283e	155	__set_bit(i, kbd->keybit);
4ee36dc0 MA	156
	157	ret = input_register_device(kbd);
	158	if (ret) {
	159	input_free_device(kbd);
	160	xenbus_dev_fatal(dev, ret, "input_register_device(kbd)");
	161	goto error;
	162	}
	163	info->kbd = kbd;
	164
	165	/* pointing device */
	166	ptr = input_allocate_device();
	167	if (!ptr)
	168	goto error_nomem;
	169	ptr->name = "Xen Virtual Pointer";
	170	ptr->phys = info->phys;
	171	ptr->id.bustype = BUS_PCI;
	172	ptr->id.vendor = 0x5853;
	173	ptr->id.product = 0xfffe;
8c3c283e OH	174
	175	if (abs) {
	176	__set_bit(EV_ABS, ptr->evbit);
	177	input_set_abs_params(ptr, ABS_X, 0, XENFB_WIDTH, 0, 0);
	178	input_set_abs_params(ptr, ABS_Y, 0, XENFB_HEIGHT, 0, 0);
	179	} else {
	180	input_set_capability(ptr, EV_REL, REL_X);
	181	input_set_capability(ptr, EV_REL, REL_Y);
	182	}
	183	input_set_capability(ptr, EV_REL, REL_WHEEL);
	184
	185	__set_bit(EV_KEY, ptr->evbit);
4ee36dc0	186	for (i = BTN_LEFT; i <= BTN_TASK; i++)
8c3c283e	187	__set_bit(i, ptr->keybit);
4ee36dc0 MA	188
	189	ret = input_register_device(ptr);
	190	if (ret) {
	191	input_free_device(ptr);
	192	xenbus_dev_fatal(dev, ret, "input_register_device(ptr)");
	193	goto error;
	194	}
	195	info->ptr = ptr;
	196
	197	ret = xenkbd_connect_backend(dev, info);
	198	if (ret < 0)
	199	goto error;
	200
	201	return 0;
	202
	203	error_nomem:
	204	ret = -ENOMEM;
	205	xenbus_dev_fatal(dev, ret, "allocating device memory");
	206	error:
	207	xenkbd_remove(dev);
	208	return ret;
	209	}
	210
	211	static int xenkbd_resume(struct xenbus_device *dev)
	212	{
1b713e00	213	struct xenkbd_info *info = dev_get_drvdata(&dev->dev);
4ee36dc0 MA	214
	215	xenkbd_disconnect_backend(info);
	216	memset(info->page, 0, PAGE_SIZE);
	217	return xenkbd_connect_backend(dev, info);
	218	}
	219
	220	static int xenkbd_remove(struct xenbus_device *dev)
	221	{
1b713e00	222	struct xenkbd_info *info = dev_get_drvdata(&dev->dev);
4ee36dc0 MA	223
	224	xenkbd_disconnect_backend(info);
	225	if (info->kbd)
	226	input_unregister_device(info->kbd);
	227	if (info->ptr)
	228	input_unregister_device(info->ptr);
	229	free_page((unsigned long)info->page);
	230	kfree(info);
	231	return 0;
	232	}
	233
	234	static int xenkbd_connect_backend(struct xenbus_device *dev,
	235	struct xenkbd_info *info)
	236	{
	237	int ret, evtchn;
	238	struct xenbus_transaction xbt;
	239
0a4dfa5d	240	ret = gnttab_grant_foreign_access(dev->otherend_id,
0df4f266	241	virt_to_gfn(info->page), 0);
0a4dfa5d DDG	242	if (ret < 0)
	243	return ret;
	244	info->gref = ret;
	245
4ee36dc0 MA	246	ret = xenbus_alloc_evtchn(dev, &evtchn);
4ee36dc0 MA	247	if (ret)
0a4dfa5d	248	goto error_grant;
4ee36dc0 MA	249	ret = bind_evtchn_to_irqhandler(evtchn, input_handler,
	250	0, dev->devicetype, info);
	251	if (ret < 0) {
4ee36dc0	252	xenbus_dev_fatal(dev, ret, "bind_evtchn_to_irqhandler");
0a4dfa5d	253	goto error_evtchan;
4ee36dc0 MA	254	}
	255	info->irq = ret;
	256
	257	again:
	258	ret = xenbus_transaction_start(&xbt);
	259	if (ret) {
	260	xenbus_dev_fatal(dev, ret, "starting transaction");
0a4dfa5d	261	goto error_irqh;
4ee36dc0 MA	262	}
4ee36dc0 MA	263	ret = xenbus_printf(xbt, dev->nodename, "page-ref", "%lu",
0df4f266	264	virt_to_gfn(info->page));
0a4dfa5d DDG	265	if (ret)
	266	goto error_xenbus;
	267	ret = xenbus_printf(xbt, dev->nodename, "page-gref", "%u", info->gref);
4ee36dc0 MA	268	if (ret)
	269	goto error_xenbus;
	270	ret = xenbus_printf(xbt, dev->nodename, "event-channel", "%u",
	271	evtchn);
	272	if (ret)
	273	goto error_xenbus;
	274	ret = xenbus_transaction_end(xbt, 0);
	275	if (ret) {
	276	if (ret == -EAGAIN)
	277	goto again;
	278	xenbus_dev_fatal(dev, ret, "completing transaction");
0a4dfa5d	279	goto error_irqh;
4ee36dc0 MA	280	}
	281
	282	xenbus_switch_state(dev, XenbusStateInitialised);
	283	return 0;
	284
	285	error_xenbus:
	286	xenbus_transaction_end(xbt, 1);
	287	xenbus_dev_fatal(dev, ret, "writing xenstore");
0a4dfa5d DDG	288	error_irqh:
	289	unbind_from_irqhandler(info->irq, info);
	290	info->irq = -1;
	291	error_evtchan:
	292	xenbus_free_evtchn(dev, evtchn);
	293	error_grant:
4d544e3b	294	gnttab_end_foreign_access(info->gref, 0, 0UL);
0a4dfa5d	295	info->gref = -1;
4ee36dc0 MA	296	return ret;
	297	}
	298
	299	static void xenkbd_disconnect_backend(struct xenkbd_info *info)
	300	{
	301	if (info->irq >= 0)
	302	unbind_from_irqhandler(info->irq, info);
	303	info->irq = -1;
0a4dfa5d	304	if (info->gref >= 0)
4d544e3b	305	gnttab_end_foreign_access(info->gref, 0, 0UL);
0a4dfa5d	306	info->gref = -1;
4ee36dc0 MA	307	}
	308
	309	static void xenkbd_backend_changed(struct xenbus_device *dev,
	310	enum xenbus_state backend_state)
	311	{
1b713e00	312	struct xenkbd_info *info = dev_get_drvdata(&dev->dev);
c36b58e8	313	int ret, val;
4ee36dc0 MA	314
	315	switch (backend_state) {
	316	case XenbusStateInitialising:
	317	case XenbusStateInitialised:
b78c9512 NI	318	case XenbusStateReconfiguring:
b78c9512 NI	319	case XenbusStateReconfigured:
4ee36dc0	320	case XenbusStateUnknown:
4ee36dc0 MA	321	break;
	322
	323	case XenbusStateInitWait:
	324	InitWait:
c36b58e8 IM	325	ret = xenbus_scanf(XBT_NIL, info->xbdev->otherend,
	326	"feature-abs-pointer", "%d", &val);
	327	if (ret < 0)
	328	val = 0;
	329	if (val) {
	330	ret = xenbus_printf(XBT_NIL, info->xbdev->nodename,
	331	"request-abs-pointer", "1");
	332	if (ret)
	333	pr_warning("xenkbd: can't request abs-pointer");
	334	}
	335
4ee36dc0 MA	336	xenbus_switch_state(dev, XenbusStateConnected);
	337	break;
	338
	339	case XenbusStateConnected:
	340	/*
	341	* Work around xenbus race condition: If backend goes
	342	* through InitWait to Connected fast enough, we can
	343	* get Connected twice here.
	344	*/
	345	if (dev->state != XenbusStateConnected)
	346	goto InitWait; /* no InitWait seen yet, fudge it */
e4dcff1f MA	347
	348	/* Set input abs params to match backend screen res */
	349	if (xenbus_scanf(XBT_NIL, info->xbdev->otherend,
	350	"width", "%d", &val) > 0)
	351	input_set_abs_params(info->ptr, ABS_X, 0, val, 0, 0);
	352
	353	if (xenbus_scanf(XBT_NIL, info->xbdev->otherend,
	354	"height", "%d", &val) > 0)
	355	input_set_abs_params(info->ptr, ABS_Y, 0, val, 0, 0);
	356
4ee36dc0 MA	357	break;
4ee36dc0 MA	358
2ebb939a DV	359	case XenbusStateClosed:
	360	if (dev->state == XenbusStateClosed)
	361	break;
	362	/* Missed the backend's CLOSING state -- fallthrough */
4ee36dc0 MA	363	case XenbusStateClosing:
	364	xenbus_frontend_closed(dev);
	365	break;
	366	}
	367	}
	368
c6d57093	369	static const struct xenbus_device_id xenkbd_ids[] = {
4ee36dc0 MA	370	{ "vkbd" },
	371	{ "" }
	372	};
	373
95afae48 DV	374	static struct xenbus_driver xenkbd_driver = {
95afae48 DV	375	.ids = xenkbd_ids,
4ee36dc0 MA	376	.probe = xenkbd_probe,
	377	.remove = xenkbd_remove,
	378	.resume = xenkbd_resume,
	379	.otherend_changed = xenkbd_backend_changed,
95afae48	380	};
4ee36dc0 MA	381
	382	static int __init xenkbd_init(void)
	383	{
5f098ecd	384	if (!xen_domain())
4ee36dc0 MA	385	return -ENODEV;
	386
	387	/* Nothing to do if running in dom0. */
6e833587	388	if (xen_initial_domain())
4ee36dc0 MA	389	return -ENODEV;
4ee36dc0 MA	390
51c71a3b KRW	391	if (!xen_has_pv_devices())
	392	return -ENODEV;
	393
ffb78a26	394	return xenbus_register_frontend(&xenkbd_driver);
4ee36dc0 MA	395	}
	396
	397	static void __exit xenkbd_cleanup(void)
	398	{
ffb78a26	399	xenbus_unregister_driver(&xenkbd_driver);
4ee36dc0 MA	400	}
	401
	402	module_init(xenkbd_init);
	403	module_exit(xenkbd_cleanup);
	404
1e892c95	405	MODULE_DESCRIPTION("Xen virtual keyboard/pointer device frontend");
4ee36dc0	406	MODULE_LICENSE("GPL");
1e892c95	407	MODULE_ALIAS("xen:vkbd");