USB: Fix a bug on appledisplay.c regarding signedness
[linux-2.6.git] / drivers / usb / misc / appledisplay.c
1 /*
2  * Apple Cinema Display driver
3  *
4  * Copyright (C) 2006  Michael Hanselmann (linux-kernel@hansmi.ch)
5  *
6  * Thanks to Caskey L. Dickson for his work with acdctl.
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License as published by
10  * the Free Software Foundation; either version 2 of the License, or
11  * (at your option) any later version.
12  *
13  * This program is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16  * GNU General Public License for more details.
17  *
18  * You should have received a copy of the GNU General Public License
19  * along with this program; if not, write to the Free Software
20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
21  */
22
23 #include <linux/kernel.h>
24 #include <linux/errno.h>
25 #include <linux/init.h>
26 #include <linux/module.h>
27 #include <linux/usb.h>
28 #include <linux/backlight.h>
29 #include <linux/timer.h>
30 #include <linux/workqueue.h>
31 #include <asm/atomic.h>
32
33 #define APPLE_VENDOR_ID         0x05AC
34
35 #define USB_REQ_GET_REPORT      0x01
36 #define USB_REQ_SET_REPORT      0x09
37
38 #define ACD_USB_TIMEOUT         250
39
40 #define ACD_USB_EDID            0x0302
41 #define ACD_USB_BRIGHTNESS      0x0310
42
43 #define ACD_BTN_NONE            0
44 #define ACD_BTN_BRIGHT_UP       3
45 #define ACD_BTN_BRIGHT_DOWN     4
46
47 #define ACD_URB_BUFFER_LEN      2
48 #define ACD_MSG_BUFFER_LEN      2
49
50 #define APPLEDISPLAY_DEVICE(prod)                               \
51         .match_flags = USB_DEVICE_ID_MATCH_DEVICE |             \
52                        USB_DEVICE_ID_MATCH_INT_CLASS |          \
53                        USB_DEVICE_ID_MATCH_INT_PROTOCOL,        \
54         .idVendor = APPLE_VENDOR_ID,                            \
55         .idProduct = (prod),                                    \
56         .bInterfaceClass = USB_CLASS_HID,                       \
57         .bInterfaceProtocol = 0x00
58
59 /* table of devices that work with this driver */
60 static struct usb_device_id appledisplay_table [] = {
61         { APPLEDISPLAY_DEVICE(0x9218) },
62         { APPLEDISPLAY_DEVICE(0x9219) },
63         { APPLEDISPLAY_DEVICE(0x921c) },
64         { APPLEDISPLAY_DEVICE(0x921d) },
65
66         /* Terminating entry */
67         { }
68 };
69 MODULE_DEVICE_TABLE(usb, appledisplay_table);
70
71 /* Structure to hold all of our device specific stuff */
72 struct appledisplay {
73         struct usb_device *udev;        /* usb device */
74         struct urb *urb;                /* usb request block */
75         struct backlight_device *bd;    /* backlight device */
76         u8 *urbdata;                    /* interrupt URB data buffer */
77         u8 *msgdata;                    /* control message data buffer */
78
79         struct delayed_work work;
80         int button_pressed;
81         spinlock_t lock;
82 };
83
84 static atomic_t count_displays = ATOMIC_INIT(0);
85 static struct workqueue_struct *wq;
86
87 static void appledisplay_complete(struct urb *urb)
88 {
89         struct appledisplay *pdata = urb->context;
90         unsigned long flags;
91         int status = urb->status;
92         int retval;
93
94         switch (status) {
95         case 0:
96                 /* success */
97                 break;
98         case -EOVERFLOW:
99                 printk(KERN_ERR "appletouch: OVERFLOW with data "
100                         "length %d, actual length is %d\n",
101                         ACD_URB_BUFFER_LEN, pdata->urb->actual_length);
102         case -ECONNRESET:
103         case -ENOENT:
104         case -ESHUTDOWN:
105                 /* This urb is terminated, clean up */
106                 dbg("%s - urb shuttingdown with status: %d",
107                         __func__, status);
108                 return;
109         default:
110                 dbg("%s - nonzero urb status received: %d",
111                         __func__, status);
112                 goto exit;
113         }
114
115         spin_lock_irqsave(&pdata->lock, flags);
116
117         switch(pdata->urbdata[1]) {
118         case ACD_BTN_BRIGHT_UP:
119         case ACD_BTN_BRIGHT_DOWN:
120                 pdata->button_pressed = 1;
121                 queue_delayed_work(wq, &pdata->work, 0);
122                 break;
123         case ACD_BTN_NONE:
124         default:
125                 pdata->button_pressed = 0;
126                 break;
127         }
128
129         spin_unlock_irqrestore(&pdata->lock, flags);
130
131 exit:
132         retval = usb_submit_urb(pdata->urb, GFP_ATOMIC);
133         if (retval) {
134                 dev_err(&pdata->udev->dev,
135                         "%s - usb_submit_urb failed with result %d\n",
136                         __func__, retval);
137         }
138 }
139
140 static int appledisplay_bl_update_status(struct backlight_device *bd)
141 {
142         struct appledisplay *pdata = bl_get_data(bd);
143         int retval;
144
145         pdata->msgdata[0] = 0x10;
146         pdata->msgdata[1] = bd->props.brightness;
147
148         retval = usb_control_msg(
149                 pdata->udev,
150                 usb_sndctrlpipe(pdata->udev, 0),
151                 USB_REQ_SET_REPORT,
152                 USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
153                 ACD_USB_BRIGHTNESS,
154                 0,
155                 pdata->msgdata, 2,
156                 ACD_USB_TIMEOUT);
157
158         return retval;
159 }
160
161 static int appledisplay_bl_get_brightness(struct backlight_device *bd)
162 {
163         struct appledisplay *pdata = bl_get_data(bd);
164         int retval;
165
166         retval = usb_control_msg(
167                 pdata->udev,
168                 usb_rcvctrlpipe(pdata->udev, 0),
169                 USB_REQ_GET_REPORT,
170                 USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
171                 ACD_USB_BRIGHTNESS,
172                 0,
173                 pdata->msgdata, 2,
174                 ACD_USB_TIMEOUT);
175
176         if (retval < 0)
177                 return retval;
178         else
179                 return pdata->msgdata[1];
180 }
181
182 static struct backlight_ops appledisplay_bl_data = {
183         .get_brightness = appledisplay_bl_get_brightness,
184         .update_status  = appledisplay_bl_update_status,
185 };
186
187 static void appledisplay_work(struct work_struct *work)
188 {
189         struct appledisplay *pdata =
190                 container_of(work, struct appledisplay, work.work);
191         int retval;
192
193         retval = appledisplay_bl_get_brightness(pdata->bd);
194         if (retval >= 0)
195                 pdata->bd->props.brightness = retval;
196
197         /* Poll again in about 125ms if there's still a button pressed */
198         if (pdata->button_pressed)
199                 schedule_delayed_work(&pdata->work, HZ / 8);
200 }
201
202 static int appledisplay_probe(struct usb_interface *iface,
203         const struct usb_device_id *id)
204 {
205         struct appledisplay *pdata;
206         struct usb_device *udev = interface_to_usbdev(iface);
207         struct usb_host_interface *iface_desc;
208         struct usb_endpoint_descriptor *endpoint;
209         int int_in_endpointAddr = 0;
210         int i, retval = -ENOMEM, brightness;
211         char bl_name[20];
212
213         /* set up the endpoint information */
214         /* use only the first interrupt-in endpoint */
215         iface_desc = iface->cur_altsetting;
216         for (i = 0; i < iface_desc->desc.bNumEndpoints; i++) {
217                 endpoint = &iface_desc->endpoint[i].desc;
218                 if (!int_in_endpointAddr && usb_endpoint_is_int_in(endpoint)) {
219                         /* we found an interrupt in endpoint */
220                         int_in_endpointAddr = endpoint->bEndpointAddress;
221                         break;
222                 }
223         }
224         if (!int_in_endpointAddr) {
225                 dev_err(&iface->dev, "Could not find int-in endpoint\n");
226                 return -EIO;
227         }
228
229         /* allocate memory for our device state and initialize it */
230         pdata = kzalloc(sizeof(struct appledisplay), GFP_KERNEL);
231         if (!pdata) {
232                 retval = -ENOMEM;
233                 dev_err(&iface->dev, "Out of memory\n");
234                 goto error;
235         }
236
237         pdata->udev = udev;
238
239         spin_lock_init(&pdata->lock);
240         INIT_DELAYED_WORK(&pdata->work, appledisplay_work);
241
242         /* Allocate buffer for control messages */
243         pdata->msgdata = kmalloc(ACD_MSG_BUFFER_LEN, GFP_KERNEL);
244         if (!pdata->msgdata) {
245                 retval = -ENOMEM;
246                 dev_err(&iface->dev,
247                         "Allocating buffer for control messages failed\n");
248                 goto error;
249         }
250
251         /* Allocate interrupt URB */
252         pdata->urb = usb_alloc_urb(0, GFP_KERNEL);
253         if (!pdata->urb) {
254                 retval = -ENOMEM;
255                 dev_err(&iface->dev, "Allocating URB failed\n");
256                 goto error;
257         }
258
259         /* Allocate buffer for interrupt data */
260         pdata->urbdata = usb_buffer_alloc(pdata->udev, ACD_URB_BUFFER_LEN,
261                 GFP_KERNEL, &pdata->urb->transfer_dma);
262         if (!pdata->urbdata) {
263                 retval = -ENOMEM;
264                 dev_err(&iface->dev, "Allocating URB buffer failed\n");
265                 goto error;
266         }
267
268         /* Configure interrupt URB */
269         usb_fill_int_urb(pdata->urb, udev,
270                 usb_rcvintpipe(udev, int_in_endpointAddr),
271                 pdata->urbdata, ACD_URB_BUFFER_LEN, appledisplay_complete,
272                 pdata, 1);
273         if (usb_submit_urb(pdata->urb, GFP_KERNEL)) {
274                 retval = -EIO;
275                 dev_err(&iface->dev, "Submitting URB failed\n");
276                 goto error;
277         }
278
279         /* Register backlight device */
280         snprintf(bl_name, sizeof(bl_name), "appledisplay%d",
281                 atomic_inc_return(&count_displays) - 1);
282         pdata->bd = backlight_device_register(bl_name, NULL, pdata,
283                                                 &appledisplay_bl_data);
284         if (IS_ERR(pdata->bd)) {
285                 dev_err(&iface->dev, "Backlight registration failed\n");
286                 goto error;
287         }
288
289         pdata->bd->props.max_brightness = 0xff;
290
291         /* Try to get brightness */
292         brightness = appledisplay_bl_get_brightness(pdata->bd);
293
294         if (brightness < 0) {
295                 retval = brightness;
296                 dev_err(&iface->dev,
297                         "Error while getting initial brightness: %d\n", retval);
298                 goto error;
299         }
300
301         /* Set brightness in backlight device */
302         pdata->bd->props.brightness = brightness;
303
304         /* save our data pointer in the interface device */
305         usb_set_intfdata(iface, pdata);
306
307         printk(KERN_INFO "appledisplay: Apple Cinema Display connected\n");
308
309         return 0;
310
311 error:
312         if (pdata) {
313                 if (pdata->urb) {
314                         usb_kill_urb(pdata->urb);
315                         if (pdata->urbdata)
316                                 usb_buffer_free(pdata->udev, ACD_URB_BUFFER_LEN,
317                                         pdata->urbdata, pdata->urb->transfer_dma);
318                         usb_free_urb(pdata->urb);
319                 }
320                 if (pdata->bd && !IS_ERR(pdata->bd))
321                         backlight_device_unregister(pdata->bd);
322                 kfree(pdata->msgdata);
323         }
324         usb_set_intfdata(iface, NULL);
325         kfree(pdata);
326         return retval;
327 }
328
329 static void appledisplay_disconnect(struct usb_interface *iface)
330 {
331         struct appledisplay *pdata = usb_get_intfdata(iface);
332
333         if (pdata) {
334                 usb_kill_urb(pdata->urb);
335                 cancel_delayed_work(&pdata->work);
336                 backlight_device_unregister(pdata->bd);
337                 usb_buffer_free(pdata->udev, ACD_URB_BUFFER_LEN,
338                         pdata->urbdata, pdata->urb->transfer_dma);
339                 usb_free_urb(pdata->urb);
340                 kfree(pdata->msgdata);
341                 kfree(pdata);
342         }
343
344         printk(KERN_INFO "appledisplay: Apple Cinema Display disconnected\n");
345 }
346
347 static struct usb_driver appledisplay_driver = {
348         .name           = "appledisplay",
349         .probe          = appledisplay_probe,
350         .disconnect     = appledisplay_disconnect,
351         .id_table       = appledisplay_table,
352 };
353
354 static int __init appledisplay_init(void)
355 {
356         wq = create_singlethread_workqueue("appledisplay");
357         if (!wq) {
358                 printk(KERN_ERR "appledisplay: Could not create work queue\n");
359                 return -ENOMEM;
360         }
361
362         return usb_register(&appledisplay_driver);
363 }
364
365 static void __exit appledisplay_exit(void)
366 {
367         flush_workqueue(wq);
368         destroy_workqueue(wq);
369         usb_deregister(&appledisplay_driver);
370 }
371
372 MODULE_AUTHOR("Michael Hanselmann");
373 MODULE_DESCRIPTION("Apple Cinema Display driver");
374 MODULE_LICENSE("GPL");
375
376 module_init(appledisplay_init);
377 module_exit(appledisplay_exit);