Merge commit 'v2.6.28-rc8' into x86/mm
[linux-2.6] / drivers / input / xen-kbdfront.c
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 /*
15  * TODO:
16  *
17  * Switch to grant tables together with xen-fbfront.c.
18  */
19
20 #include <linux/kernel.h>
21 #include <linux/errno.h>
22 #include <linux/module.h>
23 #include <linux/input.h>
24 #include <asm/xen/hypervisor.h>
25 #include <xen/events.h>
26 #include <xen/page.h>
27 #include <xen/interface/io/fbif.h>
28 #include <xen/interface/io/kbdif.h>
29 #include <xen/xenbus.h>
30
31 struct xenkbd_info {
32         struct input_dev *kbd;
33         struct input_dev *ptr;
34         struct xenkbd_page *page;
35         int irq;
36         struct xenbus_device *xbdev;
37         char phys[32];
38 };
39
40 static int xenkbd_remove(struct xenbus_device *);
41 static int xenkbd_connect_backend(struct xenbus_device *, struct xenkbd_info *);
42 static void xenkbd_disconnect_backend(struct xenkbd_info *);
43
44 /*
45  * Note: if you need to send out events, see xenfb_do_update() for how
46  * to do that.
47  */
48
49 static irqreturn_t input_handler(int rq, void *dev_id)
50 {
51         struct xenkbd_info *info = dev_id;
52         struct xenkbd_page *page = info->page;
53         __u32 cons, prod;
54
55         prod = page->in_prod;
56         if (prod == page->in_cons)
57                 return IRQ_HANDLED;
58         rmb();                  /* ensure we see ring contents up to prod */
59         for (cons = page->in_cons; cons != prod; cons++) {
60                 union xenkbd_in_event *event;
61                 struct input_dev *dev;
62                 event = &XENKBD_IN_RING_REF(page, cons);
63
64                 dev = info->ptr;
65                 switch (event->type) {
66                 case XENKBD_TYPE_MOTION:
67                         input_report_rel(dev, REL_X, event->motion.rel_x);
68                         input_report_rel(dev, REL_Y, event->motion.rel_y);
69                         if (event->motion.rel_z)
70                                 input_report_rel(dev, REL_WHEEL,
71                                                  -event->motion.rel_z);
72                         break;
73                 case XENKBD_TYPE_KEY:
74                         dev = NULL;
75                         if (test_bit(event->key.keycode, info->kbd->keybit))
76                                 dev = info->kbd;
77                         if (test_bit(event->key.keycode, info->ptr->keybit))
78                                 dev = info->ptr;
79                         if (dev)
80                                 input_report_key(dev, event->key.keycode,
81                                                  event->key.pressed);
82                         else
83                                 printk(KERN_WARNING
84                                        "xenkbd: unhandled keycode 0x%x\n",
85                                        event->key.keycode);
86                         break;
87                 case XENKBD_TYPE_POS:
88                         input_report_abs(dev, ABS_X, event->pos.abs_x);
89                         input_report_abs(dev, ABS_Y, event->pos.abs_y);
90                         if (event->pos.rel_z)
91                                 input_report_rel(dev, REL_WHEEL,
92                                                  -event->pos.rel_z);
93                         break;
94                 }
95                 if (dev)
96                         input_sync(dev);
97         }
98         mb();                   /* ensure we got ring contents */
99         page->in_cons = cons;
100         notify_remote_via_irq(info->irq);
101
102         return IRQ_HANDLED;
103 }
104
105 static int __devinit xenkbd_probe(struct xenbus_device *dev,
106                                   const struct xenbus_device_id *id)
107 {
108         int ret, i;
109         struct xenkbd_info *info;
110         struct input_dev *kbd, *ptr;
111
112         info = kzalloc(sizeof(*info), GFP_KERNEL);
113         if (!info) {
114                 xenbus_dev_fatal(dev, -ENOMEM, "allocating info structure");
115                 return -ENOMEM;
116         }
117         dev->dev.driver_data = info;
118         info->xbdev = dev;
119         info->irq = -1;
120         snprintf(info->phys, sizeof(info->phys), "xenbus/%s", dev->nodename);
121
122         info->page = (void *)__get_free_page(GFP_KERNEL | __GFP_ZERO);
123         if (!info->page)
124                 goto error_nomem;
125
126         /* keyboard */
127         kbd = input_allocate_device();
128         if (!kbd)
129                 goto error_nomem;
130         kbd->name = "Xen Virtual Keyboard";
131         kbd->phys = info->phys;
132         kbd->id.bustype = BUS_PCI;
133         kbd->id.vendor = 0x5853;
134         kbd->id.product = 0xffff;
135         kbd->evbit[0] = BIT(EV_KEY);
136         for (i = KEY_ESC; i < KEY_UNKNOWN; i++)
137                 set_bit(i, kbd->keybit);
138         for (i = KEY_OK; i < KEY_MAX; i++)
139                 set_bit(i, kbd->keybit);
140
141         ret = input_register_device(kbd);
142         if (ret) {
143                 input_free_device(kbd);
144                 xenbus_dev_fatal(dev, ret, "input_register_device(kbd)");
145                 goto error;
146         }
147         info->kbd = kbd;
148
149         /* pointing device */
150         ptr = input_allocate_device();
151         if (!ptr)
152                 goto error_nomem;
153         ptr->name = "Xen Virtual Pointer";
154         ptr->phys = info->phys;
155         ptr->id.bustype = BUS_PCI;
156         ptr->id.vendor = 0x5853;
157         ptr->id.product = 0xfffe;
158         ptr->evbit[0] = BIT(EV_KEY) | BIT(EV_REL) | BIT(EV_ABS);
159         for (i = BTN_LEFT; i <= BTN_TASK; i++)
160                 set_bit(i, ptr->keybit);
161         ptr->relbit[0] = BIT(REL_X) | BIT(REL_Y) | BIT(REL_WHEEL);
162         input_set_abs_params(ptr, ABS_X, 0, XENFB_WIDTH, 0, 0);
163         input_set_abs_params(ptr, ABS_Y, 0, XENFB_HEIGHT, 0, 0);
164
165         ret = input_register_device(ptr);
166         if (ret) {
167                 input_free_device(ptr);
168                 xenbus_dev_fatal(dev, ret, "input_register_device(ptr)");
169                 goto error;
170         }
171         info->ptr = ptr;
172
173         ret = xenkbd_connect_backend(dev, info);
174         if (ret < 0)
175                 goto error;
176
177         return 0;
178
179  error_nomem:
180         ret = -ENOMEM;
181         xenbus_dev_fatal(dev, ret, "allocating device memory");
182  error:
183         xenkbd_remove(dev);
184         return ret;
185 }
186
187 static int xenkbd_resume(struct xenbus_device *dev)
188 {
189         struct xenkbd_info *info = dev->dev.driver_data;
190
191         xenkbd_disconnect_backend(info);
192         memset(info->page, 0, PAGE_SIZE);
193         return xenkbd_connect_backend(dev, info);
194 }
195
196 static int xenkbd_remove(struct xenbus_device *dev)
197 {
198         struct xenkbd_info *info = dev->dev.driver_data;
199
200         xenkbd_disconnect_backend(info);
201         if (info->kbd)
202                 input_unregister_device(info->kbd);
203         if (info->ptr)
204                 input_unregister_device(info->ptr);
205         free_page((unsigned long)info->page);
206         kfree(info);
207         return 0;
208 }
209
210 static int xenkbd_connect_backend(struct xenbus_device *dev,
211                                   struct xenkbd_info *info)
212 {
213         int ret, evtchn;
214         struct xenbus_transaction xbt;
215
216         ret = xenbus_alloc_evtchn(dev, &evtchn);
217         if (ret)
218                 return ret;
219         ret = bind_evtchn_to_irqhandler(evtchn, input_handler,
220                                         0, dev->devicetype, info);
221         if (ret < 0) {
222                 xenbus_free_evtchn(dev, evtchn);
223                 xenbus_dev_fatal(dev, ret, "bind_evtchn_to_irqhandler");
224                 return ret;
225         }
226         info->irq = ret;
227
228  again:
229         ret = xenbus_transaction_start(&xbt);
230         if (ret) {
231                 xenbus_dev_fatal(dev, ret, "starting transaction");
232                 return ret;
233         }
234         ret = xenbus_printf(xbt, dev->nodename, "page-ref", "%lu",
235                             virt_to_mfn(info->page));
236         if (ret)
237                 goto error_xenbus;
238         ret = xenbus_printf(xbt, dev->nodename, "event-channel", "%u",
239                             evtchn);
240         if (ret)
241                 goto error_xenbus;
242         ret = xenbus_transaction_end(xbt, 0);
243         if (ret) {
244                 if (ret == -EAGAIN)
245                         goto again;
246                 xenbus_dev_fatal(dev, ret, "completing transaction");
247                 return ret;
248         }
249
250         xenbus_switch_state(dev, XenbusStateInitialised);
251         return 0;
252
253  error_xenbus:
254         xenbus_transaction_end(xbt, 1);
255         xenbus_dev_fatal(dev, ret, "writing xenstore");
256         return ret;
257 }
258
259 static void xenkbd_disconnect_backend(struct xenkbd_info *info)
260 {
261         if (info->irq >= 0)
262                 unbind_from_irqhandler(info->irq, info);
263         info->irq = -1;
264 }
265
266 static void xenkbd_backend_changed(struct xenbus_device *dev,
267                                    enum xenbus_state backend_state)
268 {
269         struct xenkbd_info *info = dev->dev.driver_data;
270         int ret, val;
271
272         switch (backend_state) {
273         case XenbusStateInitialising:
274         case XenbusStateInitialised:
275         case XenbusStateUnknown:
276         case XenbusStateClosed:
277                 break;
278
279         case XenbusStateInitWait:
280 InitWait:
281                 ret = xenbus_scanf(XBT_NIL, info->xbdev->otherend,
282                                    "feature-abs-pointer", "%d", &val);
283                 if (ret < 0)
284                         val = 0;
285                 if (val) {
286                         ret = xenbus_printf(XBT_NIL, info->xbdev->nodename,
287                                             "request-abs-pointer", "1");
288                         if (ret)
289                                 printk(KERN_WARNING
290                                        "xenkbd: can't request abs-pointer");
291                 }
292                 xenbus_switch_state(dev, XenbusStateConnected);
293                 break;
294
295         case XenbusStateConnected:
296                 /*
297                  * Work around xenbus race condition: If backend goes
298                  * through InitWait to Connected fast enough, we can
299                  * get Connected twice here.
300                  */
301                 if (dev->state != XenbusStateConnected)
302                         goto InitWait; /* no InitWait seen yet, fudge it */
303
304                 /* Set input abs params to match backend screen res */
305                 if (xenbus_scanf(XBT_NIL, info->xbdev->otherend,
306                                  "width", "%d", &val) > 0)
307                         input_set_abs_params(info->ptr, ABS_X, 0, val, 0, 0);
308
309                 if (xenbus_scanf(XBT_NIL, info->xbdev->otherend,
310                                  "height", "%d", &val) > 0)
311                         input_set_abs_params(info->ptr, ABS_Y, 0, val, 0, 0);
312
313                 break;
314
315         case XenbusStateClosing:
316                 xenbus_frontend_closed(dev);
317                 break;
318         }
319 }
320
321 static struct xenbus_device_id xenkbd_ids[] = {
322         { "vkbd" },
323         { "" }
324 };
325
326 static struct xenbus_driver xenkbd_driver = {
327         .name = "vkbd",
328         .owner = THIS_MODULE,
329         .ids = xenkbd_ids,
330         .probe = xenkbd_probe,
331         .remove = xenkbd_remove,
332         .resume = xenkbd_resume,
333         .otherend_changed = xenkbd_backend_changed,
334 };
335
336 static int __init xenkbd_init(void)
337 {
338         if (!xen_domain())
339                 return -ENODEV;
340
341         /* Nothing to do if running in dom0. */
342         if (xen_initial_domain())
343                 return -ENODEV;
344
345         return xenbus_register_frontend(&xenkbd_driver);
346 }
347
348 static void __exit xenkbd_cleanup(void)
349 {
350         xenbus_unregister_driver(&xenkbd_driver);
351 }
352
353 module_init(xenkbd_init);
354 module_exit(xenkbd_cleanup);
355
356 MODULE_DESCRIPTION("Xen virtual keyboard/pointer device frontend");
357 MODULE_LICENSE("GPL");
358 MODULE_ALIAS("xen:vkbd");