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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 
 89 static void appledisplay_complete(struct urb *urb)
 90 {
 91         struct appledisplay *pdata = urb->context;
 92         struct device *dev = &pdata->udev->dev;
 93         unsigned long flags;
 94         int status = urb->status;
 95         int retval;
 96 
 97         switch (status) {
 98         case 0:
 99                 /* success */
100                 break;
101         case -EOVERFLOW:
102                 dev_err(dev,
103                         "OVERFLOW with data length %d, actual length is %d\n",
104                         ACD_URB_BUFFER_LEN, pdata->urb->actual_length);
105         case -ECONNRESET:
106         case -ENOENT:
107         case -ESHUTDOWN:
108                 /* This urb is terminated, clean up */
109                 dev_dbg(dev, "%s - urb shuttingdown with status: %d\n",
110                         __func__, status);
111                 return;
112         default:
113                 dev_dbg(dev, "%s - nonzero urb status received: %d\n",
114                         __func__, status);
115                 goto exit;
116         }
117 
118         spin_lock_irqsave(&pdata->lock, flags);
119 
120         switch(pdata->urbdata[1]) {
121         case ACD_BTN_BRIGHT_UP:
122         case ACD_BTN_BRIGHT_DOWN:
123                 pdata->button_pressed = 1;
124                 schedule_delayed_work(&pdata->work, 0);
125                 break;
126         case ACD_BTN_NONE:
127         default:
128                 pdata->button_pressed = 0;
129                 break;
130         }
131 
132         spin_unlock_irqrestore(&pdata->lock, flags);
133 
134 exit:
135         retval = usb_submit_urb(pdata->urb, GFP_ATOMIC);
136         if (retval) {
137                 dev_err(dev, "%s - usb_submit_urb failed with result %d\n",
138                         __func__, retval);
139         }
140 }
141 
142 static int appledisplay_bl_update_status(struct backlight_device *bd)
143 {
144         struct appledisplay *pdata = bl_get_data(bd);
145         int retval;
146 
147         mutex_lock(&pdata->sysfslock);
148         pdata->msgdata[0] = 0x10;
149         pdata->msgdata[1] = bd->props.brightness;
150 
151         retval = usb_control_msg(
152                 pdata->udev,
153                 usb_sndctrlpipe(pdata->udev, 0),
154                 USB_REQ_SET_REPORT,
155                 USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
156                 ACD_USB_BRIGHTNESS,
157                 0,
158                 pdata->msgdata, 2,
159                 ACD_USB_TIMEOUT);
160         mutex_unlock(&pdata->sysfslock);
161         
162         return retval;
163 }
164 
165 static int appledisplay_bl_get_brightness(struct backlight_device *bd)
166 {
167         struct appledisplay *pdata = bl_get_data(bd);
168         int retval, brightness;
169 
170         mutex_lock(&pdata->sysfslock);
171         retval = usb_control_msg(
172                 pdata->udev,
173                 usb_rcvctrlpipe(pdata->udev, 0),
174                 USB_REQ_GET_REPORT,
175                 USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
176                 ACD_USB_BRIGHTNESS,
177                 0,
178                 pdata->msgdata, 2,
179                 ACD_USB_TIMEOUT);
180         brightness = pdata->msgdata[1];
181         mutex_unlock(&pdata->sysfslock);
182 
183         if (retval < 0)
184                 return retval;
185         else
186                 return brightness;
187 }
188 
189 static const struct backlight_ops appledisplay_bl_data = {
190         .get_brightness = appledisplay_bl_get_brightness,
191         .update_status  = appledisplay_bl_update_status,
192 };
193 
194 static void appledisplay_work(struct work_struct *work)
195 {
196         struct appledisplay *pdata =
197                 container_of(work, struct appledisplay, work.work);
198         int retval;
199 
200         retval = appledisplay_bl_get_brightness(pdata->bd);
201         if (retval >= 0)
202                 pdata->bd->props.brightness = retval;
203 
204         /* Poll again in about 125ms if there's still a button pressed */
205         if (pdata->button_pressed)
206                 schedule_delayed_work(&pdata->work, HZ / 8);
207 }
208 
209 static int appledisplay_probe(struct usb_interface *iface,
210         const struct usb_device_id *id)
211 {
212         struct backlight_properties props;
213         struct appledisplay *pdata;
214         struct usb_device *udev = interface_to_usbdev(iface);
215         struct usb_host_interface *iface_desc;
216         struct usb_endpoint_descriptor *endpoint;
217         int int_in_endpointAddr = 0;
218         int i, retval = -ENOMEM, brightness;
219         char bl_name[20];
220 
221         /* set up the endpoint information */
222         /* use only the first interrupt-in endpoint */
223         iface_desc = iface->cur_altsetting;
224         for (i = 0; i < iface_desc->desc.bNumEndpoints; i++) {
225                 endpoint = &iface_desc->endpoint[i].desc;
226                 if (!int_in_endpointAddr && usb_endpoint_is_int_in(endpoint)) {
227                         /* we found an interrupt in endpoint */
228                         int_in_endpointAddr = endpoint->bEndpointAddress;
229                         break;
230                 }
231         }
232         if (!int_in_endpointAddr) {
233                 dev_err(&iface->dev, "Could not find int-in endpoint\n");
234                 return -EIO;
235         }
236 
237         /* allocate memory for our device state and initialize it */
238         pdata = kzalloc(sizeof(struct appledisplay), GFP_KERNEL);
239         if (!pdata) {
240                 retval = -ENOMEM;
241                 goto error;
242         }
243 
244         pdata->udev = udev;
245 
246         spin_lock_init(&pdata->lock);
247         INIT_DELAYED_WORK(&pdata->work, appledisplay_work);
248         mutex_init(&pdata->sysfslock);
249 
250         /* Allocate buffer for control messages */
251         pdata->msgdata = kmalloc(ACD_MSG_BUFFER_LEN, GFP_KERNEL);
252         if (!pdata->msgdata) {
253                 retval = -ENOMEM;
254                 goto error;
255         }
256 
257         /* Allocate interrupt URB */
258         pdata->urb = usb_alloc_urb(0, GFP_KERNEL);
259         if (!pdata->urb) {
260                 retval = -ENOMEM;
261                 goto error;
262         }
263 
264         /* Allocate buffer for interrupt data */
265         pdata->urbdata = usb_alloc_coherent(pdata->udev, ACD_URB_BUFFER_LEN,
266                 GFP_KERNEL, &pdata->urb->transfer_dma);
267         if (!pdata->urbdata) {
268                 retval = -ENOMEM;
269                 dev_err(&iface->dev, "Allocating URB buffer failed\n");
270                 goto error;
271         }
272 
273         /* Configure interrupt URB */
274         usb_fill_int_urb(pdata->urb, udev,
275                 usb_rcvintpipe(udev, int_in_endpointAddr),
276                 pdata->urbdata, ACD_URB_BUFFER_LEN, appledisplay_complete,
277                 pdata, 1);
278         if (usb_submit_urb(pdata->urb, GFP_KERNEL)) {
279                 retval = -EIO;
280                 dev_err(&iface->dev, "Submitting URB failed\n");
281                 goto error;
282         }
283 
284         /* Register backlight device */
285         snprintf(bl_name, sizeof(bl_name), "appledisplay%d",
286                 atomic_inc_return(&count_displays) - 1);
287         memset(&props, 0, sizeof(struct backlight_properties));
288         props.type = BACKLIGHT_RAW;
289         props.max_brightness = 0xff;
290         pdata->bd = backlight_device_register(bl_name, NULL, pdata,
291                                               &appledisplay_bl_data, &props);
292         if (IS_ERR(pdata->bd)) {
293                 dev_err(&iface->dev, "Backlight registration failed\n");
294                 retval = PTR_ERR(pdata->bd);
295                 goto error;
296         }
297 
298         /* Try to get brightness */
299         brightness = appledisplay_bl_get_brightness(pdata->bd);
300 
301         if (brightness < 0) {
302                 retval = brightness;
303                 dev_err(&iface->dev,
304                         "Error while getting initial brightness: %d\n", retval);
305                 goto error;
306         }
307 
308         /* Set brightness in backlight device */
309         pdata->bd->props.brightness = brightness;
310 
311         /* save our data pointer in the interface device */
312         usb_set_intfdata(iface, pdata);
313 
314         printk(KERN_INFO "appledisplay: Apple Cinema Display connected\n");
315 
316         return 0;
317 
318 error:
319         if (pdata) {
320                 if (pdata->urb) {
321                         usb_kill_urb(pdata->urb);
322                         if (pdata->urbdata)
323                                 usb_free_coherent(pdata->udev, ACD_URB_BUFFER_LEN,
324                                         pdata->urbdata, pdata->urb->transfer_dma);
325                         usb_free_urb(pdata->urb);
326                 }
327                 if (!IS_ERR(pdata->bd))
328                         backlight_device_unregister(pdata->bd);
329                 kfree(pdata->msgdata);
330         }
331         usb_set_intfdata(iface, NULL);
332         kfree(pdata);
333         return retval;
334 }
335 
336 static void appledisplay_disconnect(struct usb_interface *iface)
337 {
338         struct appledisplay *pdata = usb_get_intfdata(iface);
339 
340         if (pdata) {
341                 usb_kill_urb(pdata->urb);
342                 cancel_delayed_work_sync(&pdata->work);
343                 backlight_device_unregister(pdata->bd);
344                 usb_free_coherent(pdata->udev, ACD_URB_BUFFER_LEN,
345                         pdata->urbdata, pdata->urb->transfer_dma);
346                 usb_free_urb(pdata->urb);
347                 kfree(pdata->msgdata);
348                 kfree(pdata);
349         }
350 
351         printk(KERN_INFO "appledisplay: Apple Cinema Display disconnected\n");
352 }
353 
354 static struct usb_driver appledisplay_driver = {
355         .name           = "appledisplay",
356         .probe          = appledisplay_probe,
357         .disconnect     = appledisplay_disconnect,
358         .id_table       = appledisplay_table,
359 };
360 
361 static int __init appledisplay_init(void)
362 {
363         return usb_register(&appledisplay_driver);
364 }
365 
366 static void __exit appledisplay_exit(void)
367 {
368         usb_deregister(&appledisplay_driver);
369 }
370 
371 MODULE_AUTHOR("Michael Hanselmann");
372 MODULE_DESCRIPTION("Apple Cinema Display driver");
373 MODULE_LICENSE("GPL");
374 
375 module_init(appledisplay_init);
376 module_exit(appledisplay_exit);
377 

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