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
33 struct 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
43 static int xenkbd_remove(struct xenbus_device *);
44 static int xenkbd_connect_backend(struct xenbus_device *, struct xenkbd_info *);
45 static 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
input_handler(int rq,void * dev_id)52 static 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
xenkbd_probe(struct xenbus_device * dev,const struct xenbus_device_id * id)107 static int 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
xenkbd_resume(struct xenbus_device * dev)204 static 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
xenkbd_remove(struct xenbus_device * dev)213 static 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
xenkbd_connect_backend(struct xenbus_device * dev,struct xenkbd_info * info)227 static 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
xenkbd_disconnect_backend(struct xenkbd_info * info)292 static 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
xenkbd_backend_changed(struct xenbus_device * dev,enum xenbus_state backend_state)302 static 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 break;
315
316 case XenbusStateInitWait:
317 InitWait:
318 ret = xenbus_scanf(XBT_NIL, info->xbdev->otherend,
319 "feature-abs-pointer", "%d", &val);
320 if (ret < 0)
321 val = 0;
322 if (val) {
323 ret = xenbus_printf(XBT_NIL, info->xbdev->nodename,
324 "request-abs-pointer", "1");
325 if (ret)
326 pr_warning("xenkbd: can't request abs-pointer");
327 }
328
329 xenbus_switch_state(dev, XenbusStateConnected);
330 break;
331
332 case XenbusStateConnected:
333 /*
334 * Work around xenbus race condition: If backend goes
335 * through InitWait to Connected fast enough, we can
336 * get Connected twice here.
337 */
338 if (dev->state != XenbusStateConnected)
339 goto InitWait; /* no InitWait seen yet, fudge it */
340
341 /* Set input abs params to match backend screen res */
342 if (xenbus_scanf(XBT_NIL, info->xbdev->otherend,
343 "width", "%d", &val) > 0)
344 input_set_abs_params(info->ptr, ABS_X, 0, val, 0, 0);
345
346 if (xenbus_scanf(XBT_NIL, info->xbdev->otherend,
347 "height", "%d", &val) > 0)
348 input_set_abs_params(info->ptr, ABS_Y, 0, val, 0, 0);
349
350 break;
351
352 case XenbusStateClosed:
353 if (dev->state == XenbusStateClosed)
354 break;
355 /* Missed the backend's CLOSING state -- fallthrough */
356 case XenbusStateClosing:
357 xenbus_frontend_closed(dev);
358 break;
359 }
360 }
361
362 static const struct xenbus_device_id xenkbd_ids[] = {
363 { "vkbd" },
364 { "" }
365 };
366
367 static DEFINE_XENBUS_DRIVER(xenkbd, ,
368 .probe = xenkbd_probe,
369 .remove = xenkbd_remove,
370 .resume = xenkbd_resume,
371 .otherend_changed = xenkbd_backend_changed,
372 );
373
xenkbd_init(void)374 static int __init xenkbd_init(void)
375 {
376 if (!xen_domain())
377 return -ENODEV;
378
379 /* Nothing to do if running in dom0. */
380 if (xen_initial_domain())
381 return -ENODEV;
382
383 return xenbus_register_frontend(&xenkbd_driver);
384 }
385
xenkbd_cleanup(void)386 static void __exit xenkbd_cleanup(void)
387 {
388 xenbus_unregister_driver(&xenkbd_driver);
389 }
390
391 module_init(xenkbd_init);
392 module_exit(xenkbd_cleanup);
393
394 MODULE_DESCRIPTION("Xen virtual keyboard/pointer device frontend");
395 MODULE_LICENSE("GPL");
396 MODULE_ALIAS("xen:vkbd");
397