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
14#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
15
16#include <linux/kernel.h>
17#include <linux/errno.h>
18#include <linux/module.h>
19#include <linux/input.h>
20#include <linux/slab.h>
21
22#include <asm/xen/hypervisor.h>
23
24#include <xen/xen.h>
25#include <xen/events.h>
26#include <xen/page.h>
27#include <xen/grant_table.h>
28#include <xen/interface/grant_table.h>
29#include <xen/interface/io/fbif.h>
30#include <xen/interface/io/kbdif.h>
31#include <xen/xenbus.h>
32
33struct xenkbd_info {
34	struct input_dev *kbd;
35	struct input_dev *ptr;
36	struct xenkbd_page *page;
37	int gref;
38	int irq;
39	struct xenbus_device *xbdev;
40	char phys[32];
41};
42
43static int xenkbd_remove(struct xenbus_device *);
44static int xenkbd_connect_backend(struct xenbus_device *, struct xenkbd_info *);
45static void xenkbd_disconnect_backend(struct xenkbd_info *);
46
47/*
48 * Note: if you need to send out events, see xenfb_do_update() for how
49 * to do that.
50 */
51
52static irqreturn_t input_handler(int rq, void *dev_id)
53{
54	struct xenkbd_info *info = dev_id;
55	struct xenkbd_page *page = info->page;
56	__u32 cons, prod;
57
58	prod = page->in_prod;
59	if (prod == page->in_cons)
60		return IRQ_HANDLED;
61	rmb();			/* ensure we see ring contents up to prod */
62	for (cons = page->in_cons; cons != prod; cons++) {
63		union xenkbd_in_event *event;
64		struct input_dev *dev;
65		event = &XENKBD_IN_RING_REF(page, cons);
66
67		dev = info->ptr;
68		switch (event->type) {
69		case XENKBD_TYPE_MOTION:
70			input_report_rel(dev, REL_X, event->motion.rel_x);
71			input_report_rel(dev, REL_Y, event->motion.rel_y);
72			if (event->motion.rel_z)
73				input_report_rel(dev, REL_WHEEL,
74						 -event->motion.rel_z);
75			break;
76		case XENKBD_TYPE_KEY:
77			dev = NULL;
78			if (test_bit(event->key.keycode, info->kbd->keybit))
79				dev = info->kbd;
80			if (test_bit(event->key.keycode, info->ptr->keybit))
81				dev = info->ptr;
82			if (dev)
83				input_report_key(dev, event->key.keycode,
84						 event->key.pressed);
85			else
86				pr_warning("unhandled keycode 0x%x\n",
87					   event->key.keycode);
88			break;
89		case XENKBD_TYPE_POS:
90			input_report_abs(dev, ABS_X, event->pos.abs_x);
91			input_report_abs(dev, ABS_Y, event->pos.abs_y);
92			if (event->pos.rel_z)
93				input_report_rel(dev, REL_WHEEL,
94						 -event->pos.rel_z);
95			break;
96		}
97		if (dev)
98			input_sync(dev);
99	}
100	mb();			/* ensure we got ring contents */
101	page->in_cons = cons;
102	notify_remote_via_irq(info->irq);
103
104	return IRQ_HANDLED;
105}
106
107static int __devinit xenkbd_probe(struct xenbus_device *dev,
108				  const struct xenbus_device_id *id)
109{
110	int ret, i, abs;
111	struct xenkbd_info *info;
112	struct input_dev *kbd, *ptr;
113
114	info = kzalloc(sizeof(*info), GFP_KERNEL);
115	if (!info) {
116		xenbus_dev_fatal(dev, -ENOMEM, "allocating info structure");
117		return -ENOMEM;
118	}
119	dev_set_drvdata(&dev->dev, info);
120	info->xbdev = dev;
121	info->irq = -1;
122	info->gref = -1;
123	snprintf(info->phys, sizeof(info->phys), "xenbus/%s", dev->nodename);
124
125	info->page = (void *)__get_free_page(GFP_KERNEL | __GFP_ZERO);
126	if (!info->page)
127		goto error_nomem;
128
129	if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-abs-pointer", "%d", &abs) < 0)
130		abs = 0;
131	if (abs)
132		xenbus_printf(XBT_NIL, dev->nodename, "request-abs-pointer", "1");
133
134	/* keyboard */
135	kbd = input_allocate_device();
136	if (!kbd)
137		goto error_nomem;
138	kbd->name = "Xen Virtual Keyboard";
139	kbd->phys = info->phys;
140	kbd->id.bustype = BUS_PCI;
141	kbd->id.vendor = 0x5853;
142	kbd->id.product = 0xffff;
143
144	__set_bit(EV_KEY, kbd->evbit);
145	for (i = KEY_ESC; i < KEY_UNKNOWN; i++)
146		__set_bit(i, kbd->keybit);
147	for (i = KEY_OK; i < KEY_MAX; i++)
148		__set_bit(i, kbd->keybit);
149
150	ret = input_register_device(kbd);
151	if (ret) {
152		input_free_device(kbd);
153		xenbus_dev_fatal(dev, ret, "input_register_device(kbd)");
154		goto error;
155	}
156	info->kbd = kbd;
157
158	/* pointing device */
159	ptr = input_allocate_device();
160	if (!ptr)
161		goto error_nomem;
162	ptr->name = "Xen Virtual Pointer";
163	ptr->phys = info->phys;
164	ptr->id.bustype = BUS_PCI;
165	ptr->id.vendor = 0x5853;
166	ptr->id.product = 0xfffe;
167
168	if (abs) {
169		__set_bit(EV_ABS, ptr->evbit);
170		input_set_abs_params(ptr, ABS_X, 0, XENFB_WIDTH, 0, 0);
171		input_set_abs_params(ptr, ABS_Y, 0, XENFB_HEIGHT, 0, 0);
172	} else {
173		input_set_capability(ptr, EV_REL, REL_X);
174		input_set_capability(ptr, EV_REL, REL_Y);
175	}
176	input_set_capability(ptr, EV_REL, REL_WHEEL);
177
178	__set_bit(EV_KEY, ptr->evbit);
179	for (i = BTN_LEFT; i <= BTN_TASK; i++)
180		__set_bit(i, ptr->keybit);
181
182	ret = input_register_device(ptr);
183	if (ret) {
184		input_free_device(ptr);
185		xenbus_dev_fatal(dev, ret, "input_register_device(ptr)");
186		goto error;
187	}
188	info->ptr = ptr;
189
190	ret = xenkbd_connect_backend(dev, info);
191	if (ret < 0)
192		goto error;
193
194	return 0;
195
196 error_nomem:
197	ret = -ENOMEM;
198	xenbus_dev_fatal(dev, ret, "allocating device memory");
199 error:
200	xenkbd_remove(dev);
201	return ret;
202}
203
204static int xenkbd_resume(struct xenbus_device *dev)
205{
206	struct xenkbd_info *info = dev_get_drvdata(&dev->dev);
207
208	xenkbd_disconnect_backend(info);
209	memset(info->page, 0, PAGE_SIZE);
210	return xenkbd_connect_backend(dev, info);
211}
212
213static int xenkbd_remove(struct xenbus_device *dev)
214{
215	struct xenkbd_info *info = dev_get_drvdata(&dev->dev);
216
217	xenkbd_disconnect_backend(info);
218	if (info->kbd)
219		input_unregister_device(info->kbd);
220	if (info->ptr)
221		input_unregister_device(info->ptr);
222	free_page((unsigned long)info->page);
223	kfree(info);
224	return 0;
225}
226
227static int xenkbd_connect_backend(struct xenbus_device *dev,
228				  struct xenkbd_info *info)
229{
230	int ret, evtchn;
231	struct xenbus_transaction xbt;
232
233	ret = gnttab_grant_foreign_access(dev->otherend_id,
234	                                  virt_to_mfn(info->page), 0);
235	if (ret < 0)
236		return ret;
237	info->gref = ret;
238
239	ret = xenbus_alloc_evtchn(dev, &evtchn);
240	if (ret)
241		goto error_grant;
242	ret = bind_evtchn_to_irqhandler(evtchn, input_handler,
243					0, dev->devicetype, info);
244	if (ret < 0) {
245		xenbus_dev_fatal(dev, ret, "bind_evtchn_to_irqhandler");
246		goto error_evtchan;
247	}
248	info->irq = ret;
249
250 again:
251	ret = xenbus_transaction_start(&xbt);
252	if (ret) {
253		xenbus_dev_fatal(dev, ret, "starting transaction");
254		goto error_irqh;
255	}
256	ret = xenbus_printf(xbt, dev->nodename, "page-ref", "%lu",
257			    virt_to_mfn(info->page));
258	if (ret)
259		goto error_xenbus;
260	ret = xenbus_printf(xbt, dev->nodename, "page-gref", "%u", info->gref);
261	if (ret)
262		goto error_xenbus;
263	ret = xenbus_printf(xbt, dev->nodename, "event-channel", "%u",
264			    evtchn);
265	if (ret)
266		goto error_xenbus;
267	ret = xenbus_transaction_end(xbt, 0);
268	if (ret) {
269		if (ret == -EAGAIN)
270			goto again;
271		xenbus_dev_fatal(dev, ret, "completing transaction");
272		goto error_irqh;
273	}
274
275	xenbus_switch_state(dev, XenbusStateInitialised);
276	return 0;
277
278 error_xenbus:
279	xenbus_transaction_end(xbt, 1);
280	xenbus_dev_fatal(dev, ret, "writing xenstore");
281 error_irqh:
282	unbind_from_irqhandler(info->irq, info);
283	info->irq = -1;
284 error_evtchan:
285	xenbus_free_evtchn(dev, evtchn);
286 error_grant:
287	gnttab_end_foreign_access_ref(info->gref, 0);
288	info->gref = -1;
289	return ret;
290}
291
292static void xenkbd_disconnect_backend(struct xenkbd_info *info)
293{
294	if (info->irq >= 0)
295		unbind_from_irqhandler(info->irq, info);
296	info->irq = -1;
297	if (info->gref >= 0)
298		gnttab_end_foreign_access_ref(info->gref, 0);
299	info->gref = -1;
300}
301
302static void xenkbd_backend_changed(struct xenbus_device *dev,
303				   enum xenbus_state backend_state)
304{
305	struct xenkbd_info *info = dev_get_drvdata(&dev->dev);
306	int ret, val;
307
308	switch (backend_state) {
309	case XenbusStateInitialising:
310	case XenbusStateInitialised:
311	case XenbusStateReconfiguring:
312	case XenbusStateReconfigured:
313	case XenbusStateUnknown:
314	case XenbusStateClosed:
315		break;
316
317	case XenbusStateInitWait:
318InitWait:
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
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 */
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
351		break;
352
353	case XenbusStateClosing:
354		xenbus_frontend_closed(dev);
355		break;
356	}
357}
358
359static const struct xenbus_device_id xenkbd_ids[] = {
360	{ "vkbd" },
361	{ "" }
362};
363
364static DEFINE_XENBUS_DRIVER(xenkbd, ,
365	.probe = xenkbd_probe,
366	.remove = xenkbd_remove,
367	.resume = xenkbd_resume,
368	.otherend_changed = xenkbd_backend_changed,
369);
370
371static int __init xenkbd_init(void)
372{
373	if (!xen_domain())
374		return -ENODEV;
375
376	/* Nothing to do if running in dom0. */
377	if (xen_initial_domain())
378		return -ENODEV;
379
380	return xenbus_register_frontend(&xenkbd_driver);
381}
382
383static void __exit xenkbd_cleanup(void)
384{
385	xenbus_unregister_driver(&xenkbd_driver);
386}
387
388module_init(xenkbd_init);
389module_exit(xenkbd_cleanup);
390
391MODULE_DESCRIPTION("Xen virtual keyboard/pointer device frontend");
392MODULE_LICENSE("GPL");
393MODULE_ALIAS("xen:vkbd");
394