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Linux/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/slab.h>
 28 #include <linux/usb.h>
 29 #include <linux/backlight.h>
 30 #include <linux/timer.h>
 31 #include <linux/workqueue.h>
 32 #include <linux/atomic.h>
 33 
 34 #define APPLE_VENDOR_ID         0x05AC
 35 
 36 #define USB_REQ_GET_REPORT      0x01
 37 #define USB_REQ_SET_REPORT      0x09
 38 
 39 #define ACD_USB_TIMEOUT         250
 40 
 41 #define ACD_USB_EDID            0x0302
 42 #define ACD_USB_BRIGHTNESS      0x0310
 43 
 44 #define ACD_BTN_NONE            0
 45 #define ACD_BTN_BRIGHT_UP       3
 46 #define ACD_BTN_BRIGHT_DOWN     4
 47 
 48 #define ACD_URB_BUFFER_LEN      2
 49 #define ACD_MSG_BUFFER_LEN      2
 50 
 51 #define APPLEDISPLAY_DEVICE(prod)                               \
 52         .match_flags = USB_DEVICE_ID_MATCH_DEVICE |             \
 53                        USB_DEVICE_ID_MATCH_INT_CLASS |          \
 54                        USB_DEVICE_ID_MATCH_INT_PROTOCOL,        \
 55         .idVendor = APPLE_VENDOR_ID,                            \
 56         .idProduct = (prod),                                    \
 57         .bInterfaceClass = USB_CLASS_HID,                       \
 58         .bInterfaceProtocol = 0x00
 59 
 60 /* table of devices that work with this driver */
 61 static const struct usb_device_id appledisplay_table[] = {
 62         { APPLEDISPLAY_DEVICE(0x9218) },
 63         { APPLEDISPLAY_DEVICE(0x9219) },
 64         { APPLEDISPLAY_DEVICE(0x921c) },
 65         { APPLEDISPLAY_DEVICE(0x921d) },
 66         { APPLEDISPLAY_DEVICE(0x9236) },
 67 
 68         /* Terminating entry */
 69         { }
 70 };
 71 MODULE_DEVICE_TABLE(usb, appledisplay_table);
 72 
 73 /* Structure to hold all of our device specific stuff */
 74 struct appledisplay {
 75         struct usb_device *udev;        /* usb device */
 76         struct urb *urb;                /* usb request block */
 77         struct backlight_device *bd;    /* backlight device */
 78         u8 *urbdata;                    /* interrupt URB data buffer */
 79         u8 *msgdata;                    /* control message data buffer */
 80 
 81         struct delayed_work work;
 82         int button_pressed;
 83         spinlock_t lock;
 84         struct mutex sysfslock;         /* concurrent read and write */
 85 };
 86 
 87 static atomic_t count_displays = ATOMIC_INIT(0);
 88 static struct workqueue_struct *wq;
 89 
 90 static void appledisplay_complete(struct urb *urb)
 91 {
 92         struct appledisplay *pdata = urb->context;
 93         struct device *dev = &pdata->udev->dev;
 94         unsigned long flags;
 95         int status = urb->status;
 96         int retval;
 97 
 98         switch (status) {
 99         case 0:
100                 /* success */
101                 break;
102         case -EOVERFLOW:
103                 dev_err(dev,
104                         "OVERFLOW with data length %d, actual length is %d\n",
105                         ACD_URB_BUFFER_LEN, pdata->urb->actual_length);
106         case -ECONNRESET:
107         case -ENOENT:
108         case -ESHUTDOWN:
109                 /* This urb is terminated, clean up */
110                 dev_dbg(dev, "%s - urb shuttingdown with status: %d\n",
111                         __func__, status);
112                 return;
113         default:
114                 dev_dbg(dev, "%s - nonzero urb status received: %d\n",
115                         __func__, status);
116                 goto exit;
117         }
118 
119         spin_lock_irqsave(&pdata->lock, flags);
120 
121         switch(pdata->urbdata[1]) {
122         case ACD_BTN_BRIGHT_UP:
123         case ACD_BTN_BRIGHT_DOWN:
124                 pdata->button_pressed = 1;
125                 queue_delayed_work(wq, &pdata->work, 0);
126                 break;
127         case ACD_BTN_NONE:
128         default:
129                 pdata->button_pressed = 0;
130                 break;
131         }
132 
133         spin_unlock_irqrestore(&pdata->lock, flags);
134 
135 exit:
136         retval = usb_submit_urb(pdata->urb, GFP_ATOMIC);
137         if (retval) {
138                 dev_err(dev, "%s - usb_submit_urb failed with result %d\n",
139                         __func__, retval);
140         }
141 }
142 
143 static int appledisplay_bl_update_status(struct backlight_device *bd)
144 {
145         struct appledisplay *pdata = bl_get_data(bd);
146         int retval;
147 
148         mutex_lock(&pdata->sysfslock);
149         pdata->msgdata[0] = 0x10;
150         pdata->msgdata[1] = bd->props.brightness;
151 
152         retval = usb_control_msg(
153                 pdata->udev,
154                 usb_sndctrlpipe(pdata->udev, 0),
155                 USB_REQ_SET_REPORT,
156                 USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
157                 ACD_USB_BRIGHTNESS,
158                 0,
159                 pdata->msgdata, 2,
160                 ACD_USB_TIMEOUT);
161         mutex_unlock(&pdata->sysfslock);
162         
163         return retval;
164 }
165 
166 static int appledisplay_bl_get_brightness(struct backlight_device *bd)
167 {
168         struct appledisplay *pdata = bl_get_data(bd);
169         int retval, brightness;
170 
171         mutex_lock(&pdata->sysfslock);
172         retval = usb_control_msg(
173                 pdata->udev,
174                 usb_rcvctrlpipe(pdata->udev, 0),
175                 USB_REQ_GET_REPORT,
176                 USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
177                 ACD_USB_BRIGHTNESS,
178                 0,
179                 pdata->msgdata, 2,
180                 ACD_USB_TIMEOUT);
181         brightness = pdata->msgdata[1];
182         mutex_unlock(&pdata->sysfslock);
183 
184         if (retval < 0)
185                 return retval;
186         else
187                 return brightness;
188 }
189 
190 static const struct backlight_ops appledisplay_bl_data = {
191         .get_brightness = appledisplay_bl_get_brightness,
192         .update_status  = appledisplay_bl_update_status,
193 };
194 
195 static void appledisplay_work(struct work_struct *work)
196 {
197         struct appledisplay *pdata =
198                 container_of(work, struct appledisplay, work.work);
199         int retval;
200 
201         retval = appledisplay_bl_get_brightness(pdata->bd);
202         if (retval >= 0)
203                 pdata->bd->props.brightness = retval;
204 
205         /* Poll again in about 125ms if there's still a button pressed */
206         if (pdata->button_pressed)
207                 schedule_delayed_work(&pdata->work, HZ / 8);
208 }
209 
210 static int appledisplay_probe(struct usb_interface *iface,
211         const struct usb_device_id *id)
212 {
213         struct backlight_properties props;
214         struct appledisplay *pdata;
215         struct usb_device *udev = interface_to_usbdev(iface);
216         struct usb_host_interface *iface_desc;
217         struct usb_endpoint_descriptor *endpoint;
218         int int_in_endpointAddr = 0;
219         int i, retval = -ENOMEM, brightness;
220         char bl_name[20];
221 
222         /* set up the endpoint information */
223         /* use only the first interrupt-in endpoint */
224         iface_desc = iface->cur_altsetting;
225         for (i = 0; i < iface_desc->desc.bNumEndpoints; i++) {
226                 endpoint = &iface_desc->endpoint[i].desc;
227                 if (!int_in_endpointAddr && usb_endpoint_is_int_in(endpoint)) {
228                         /* we found an interrupt in endpoint */
229                         int_in_endpointAddr = endpoint->bEndpointAddress;
230                         break;
231                 }
232         }
233         if (!int_in_endpointAddr) {
234                 dev_err(&iface->dev, "Could not find int-in endpoint\n");
235                 return -EIO;
236         }
237 
238         /* allocate memory for our device state and initialize it */
239         pdata = kzalloc(sizeof(struct appledisplay), GFP_KERNEL);
240         if (!pdata) {
241                 retval = -ENOMEM;
242                 dev_err(&iface->dev, "Out of memory\n");
243                 goto error;
244         }
245 
246         pdata->udev = udev;
247 
248         spin_lock_init(&pdata->lock);
249         INIT_DELAYED_WORK(&pdata->work, appledisplay_work);
250         mutex_init(&pdata->sysfslock);
251 
252         /* Allocate buffer for control messages */
253         pdata->msgdata = kmalloc(ACD_MSG_BUFFER_LEN, GFP_KERNEL);
254         if (!pdata->msgdata) {
255                 retval = -ENOMEM;
256                 dev_err(&iface->dev,
257                         "Allocating buffer for control messages failed\n");
258                 goto error;
259         }
260 
261         /* Allocate interrupt URB */
262         pdata->urb = usb_alloc_urb(0, GFP_KERNEL);
263         if (!pdata->urb) {
264                 retval = -ENOMEM;
265                 dev_err(&iface->dev, "Allocating URB failed\n");
266                 goto error;
267         }
268 
269         /* Allocate buffer for interrupt data */
270         pdata->urbdata = usb_alloc_coherent(pdata->udev, ACD_URB_BUFFER_LEN,
271                 GFP_KERNEL, &pdata->urb->transfer_dma);
272         if (!pdata->urbdata) {
273                 retval = -ENOMEM;
274                 dev_err(&iface->dev, "Allocating URB buffer failed\n");
275                 goto error;
276         }
277 
278         /* Configure interrupt URB */
279         usb_fill_int_urb(pdata->urb, udev,
280                 usb_rcvintpipe(udev, int_in_endpointAddr),
281                 pdata->urbdata, ACD_URB_BUFFER_LEN, appledisplay_complete,
282                 pdata, 1);
283         if (usb_submit_urb(pdata->urb, GFP_KERNEL)) {
284                 retval = -EIO;
285                 dev_err(&iface->dev, "Submitting URB failed\n");
286                 goto error;
287         }
288 
289         /* Register backlight device */
290         snprintf(bl_name, sizeof(bl_name), "appledisplay%d",
291                 atomic_inc_return(&count_displays) - 1);
292         memset(&props, 0, sizeof(struct backlight_properties));
293         props.type = BACKLIGHT_RAW;
294         props.max_brightness = 0xff;
295         pdata->bd = backlight_device_register(bl_name, NULL, pdata,
296                                               &appledisplay_bl_data, &props);
297         if (IS_ERR(pdata->bd)) {
298                 dev_err(&iface->dev, "Backlight registration failed\n");
299                 retval = PTR_ERR(pdata->bd);
300                 goto error;
301         }
302 
303         /* Try to get brightness */
304         brightness = appledisplay_bl_get_brightness(pdata->bd);
305 
306         if (brightness < 0) {
307                 retval = brightness;
308                 dev_err(&iface->dev,
309                         "Error while getting initial brightness: %d\n", retval);
310                 goto error;
311         }
312 
313         /* Set brightness in backlight device */
314         pdata->bd->props.brightness = brightness;
315 
316         /* save our data pointer in the interface device */
317         usb_set_intfdata(iface, pdata);
318 
319         printk(KERN_INFO "appledisplay: Apple Cinema Display connected\n");
320 
321         return 0;
322 
323 error:
324         if (pdata) {
325                 if (pdata->urb) {
326                         usb_kill_urb(pdata->urb);
327                         if (pdata->urbdata)
328                                 usb_free_coherent(pdata->udev, ACD_URB_BUFFER_LEN,
329                                         pdata->urbdata, pdata->urb->transfer_dma);
330                         usb_free_urb(pdata->urb);
331                 }
332                 if (pdata->bd && !IS_ERR(pdata->bd))
333                         backlight_device_unregister(pdata->bd);
334                 kfree(pdata->msgdata);
335         }
336         usb_set_intfdata(iface, NULL);
337         kfree(pdata);
338         return retval;
339 }
340 
341 static void appledisplay_disconnect(struct usb_interface *iface)
342 {
343         struct appledisplay *pdata = usb_get_intfdata(iface);
344 
345         if (pdata) {
346                 usb_kill_urb(pdata->urb);
347                 cancel_delayed_work(&pdata->work);
348                 backlight_device_unregister(pdata->bd);
349                 usb_free_coherent(pdata->udev, ACD_URB_BUFFER_LEN,
350                         pdata->urbdata, pdata->urb->transfer_dma);
351                 usb_free_urb(pdata->urb);
352                 kfree(pdata->msgdata);
353                 kfree(pdata);
354         }
355 
356         printk(KERN_INFO "appledisplay: Apple Cinema Display disconnected\n");
357 }
358 
359 static struct usb_driver appledisplay_driver = {
360         .name           = "appledisplay",
361         .probe          = appledisplay_probe,
362         .disconnect     = appledisplay_disconnect,
363         .id_table       = appledisplay_table,
364 };
365 
366 static int __init appledisplay_init(void)
367 {
368         wq = create_singlethread_workqueue("appledisplay");
369         if (!wq) {
370                 printk(KERN_ERR "appledisplay: Could not create work queue\n");
371                 return -ENOMEM;
372         }
373 
374         return usb_register(&appledisplay_driver);
375 }
376 
377 static void __exit appledisplay_exit(void)
378 {
379         flush_workqueue(wq);
380         destroy_workqueue(wq);
381         usb_deregister(&appledisplay_driver);
382 }
383 
384 MODULE_AUTHOR("Michael Hanselmann");
385 MODULE_DESCRIPTION("Apple Cinema Display driver");
386 MODULE_LICENSE("GPL");
387 
388 module_init(appledisplay_init);
389 module_exit(appledisplay_exit);
390 

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