Merge branch 'linus' into x86/urgent
[linux-2.6] / drivers / usb / misc / usblcd.c
1 /*****************************************************************************
2  *                          USBLCD Kernel Driver                             *
3  *                            Version 1.05                                   *
4  *             (C) 2005 Georges Toth <g.toth@e-biz.lu>                       *
5  *                                                                           *
6  *     This file is licensed under the GPL. See COPYING in the package.      *
7  * Based on usb-skeleton.c 2.0 by Greg Kroah-Hartman (greg@kroah.com)        *
8  *                                                                           *
9  *                                                                           *
10  * 28.02.05 Complete rewrite of the original usblcd.c driver,                *
11  *          based on usb_skeleton.c.                                         *
12  *          This new driver allows more than one USB-LCD to be connected     *
13  *          and controlled, at once                                          *
14  *****************************************************************************/
15 #include <linux/module.h>
16 #include <linux/kernel.h>
17 #include <linux/init.h>
18 #include <linux/slab.h>
19 #include <linux/errno.h>
20 #include <linux/mutex.h>
21 #include <asm/uaccess.h>
22 #include <linux/usb.h>
23
24 #define DRIVER_VERSION "USBLCD Driver Version 1.05"
25
26 #define USBLCD_MINOR            144
27
28 #define IOCTL_GET_HARD_VERSION  1
29 #define IOCTL_GET_DRV_VERSION   2
30
31
32 static struct usb_device_id id_table [] = {
33         { .idVendor = 0x10D2, .match_flags = USB_DEVICE_ID_MATCH_VENDOR, },
34         { },
35 };
36 MODULE_DEVICE_TABLE (usb, id_table);
37
38 static DEFINE_MUTEX(open_disc_mutex);
39
40
41 struct usb_lcd {
42         struct usb_device *     udev;                   /* init: probe_lcd */
43         struct usb_interface *  interface;              /* the interface for this device */
44         unsigned char *         bulk_in_buffer;         /* the buffer to receive data */
45         size_t                  bulk_in_size;           /* the size of the receive buffer */
46         __u8                    bulk_in_endpointAddr;   /* the address of the bulk in endpoint */
47         __u8                    bulk_out_endpointAddr;  /* the address of the bulk out endpoint */
48         struct kref             kref;
49         struct semaphore        limit_sem;              /* to stop writes at full throttle from
50                                                          * using up all RAM */
51         struct usb_anchor       submitted;              /* URBs to wait for before suspend */
52 };
53 #define to_lcd_dev(d) container_of(d, struct usb_lcd, kref)
54
55 #define USB_LCD_CONCURRENT_WRITES       5
56
57 static struct usb_driver lcd_driver;
58
59
60 static void lcd_delete(struct kref *kref)
61 {
62         struct usb_lcd *dev = to_lcd_dev(kref);
63
64         usb_put_dev(dev->udev);
65         kfree (dev->bulk_in_buffer);
66         kfree (dev);
67 }
68
69
70 static int lcd_open(struct inode *inode, struct file *file)
71 {
72         struct usb_lcd *dev;
73         struct usb_interface *interface;
74         int subminor, r;
75
76         subminor = iminor(inode);
77
78         interface = usb_find_interface(&lcd_driver, subminor);
79         if (!interface) {
80                 err ("USBLCD: %s - error, can't find device for minor %d",
81                      __func__, subminor);
82                 return -ENODEV;
83         }
84
85         mutex_lock(&open_disc_mutex);
86         dev = usb_get_intfdata(interface);
87         if (!dev) {
88                 mutex_unlock(&open_disc_mutex);
89                 return -ENODEV;
90         }
91
92         /* increment our usage count for the device */
93         kref_get(&dev->kref);
94         mutex_unlock(&open_disc_mutex);
95
96         /* grab a power reference */
97         r = usb_autopm_get_interface(interface);
98         if (r < 0) {
99                 kref_put(&dev->kref, lcd_delete);
100                 return r;
101         }
102
103         /* save our object in the file's private structure */
104         file->private_data = dev;
105
106         return 0;
107 }
108
109 static int lcd_release(struct inode *inode, struct file *file)
110 {
111         struct usb_lcd *dev;
112
113         dev = (struct usb_lcd *)file->private_data;
114         if (dev == NULL)
115                 return -ENODEV;
116
117         /* decrement the count on our device */
118         usb_autopm_put_interface(dev->interface);
119         kref_put(&dev->kref, lcd_delete);
120         return 0;
121 }
122
123 static ssize_t lcd_read(struct file *file, char __user * buffer, size_t count, loff_t *ppos)
124 {
125         struct usb_lcd *dev;
126         int retval = 0;
127         int bytes_read;
128
129         dev = (struct usb_lcd *)file->private_data;
130
131         /* do a blocking bulk read to get data from the device */
132         retval = usb_bulk_msg(dev->udev, 
133                               usb_rcvbulkpipe(dev->udev, dev->bulk_in_endpointAddr),
134                               dev->bulk_in_buffer,
135                               min(dev->bulk_in_size, count),
136                               &bytes_read, 10000);
137
138         /* if the read was successful, copy the data to userspace */
139         if (!retval) {
140                 if (copy_to_user(buffer, dev->bulk_in_buffer, bytes_read))
141                         retval = -EFAULT;
142                 else
143                         retval = bytes_read;
144         }
145
146         return retval;
147 }
148
149 static int lcd_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
150 {
151         struct usb_lcd *dev;
152         u16 bcdDevice;
153         char buf[30];
154
155         dev = (struct usb_lcd *)file->private_data;
156         if (dev == NULL)
157                 return -ENODEV;
158         
159         switch (cmd) {
160         case IOCTL_GET_HARD_VERSION:
161                 bcdDevice = le16_to_cpu((dev->udev)->descriptor.bcdDevice);
162                 sprintf(buf,"%1d%1d.%1d%1d",
163                         (bcdDevice & 0xF000)>>12,
164                         (bcdDevice & 0xF00)>>8,
165                         (bcdDevice & 0xF0)>>4,
166                         (bcdDevice & 0xF));
167                 if (copy_to_user((void __user *)arg,buf,strlen(buf))!=0)
168                         return -EFAULT;
169                 break;
170         case IOCTL_GET_DRV_VERSION:
171                 sprintf(buf,DRIVER_VERSION);
172                 if (copy_to_user((void __user *)arg,buf,strlen(buf))!=0)
173                         return -EFAULT;
174                 break;
175         default:
176                 return -ENOTTY;
177                 break;
178         }
179
180         return 0;
181 }
182
183 static void lcd_write_bulk_callback(struct urb *urb)
184 {
185         struct usb_lcd *dev;
186         int status = urb->status;
187
188         dev = urb->context;
189
190         /* sync/async unlink faults aren't errors */
191         if (status &&
192             !(status == -ENOENT ||
193               status == -ECONNRESET ||
194               status == -ESHUTDOWN)) {
195                 dbg("USBLCD: %s - nonzero write bulk status received: %d",
196                     __func__, status);
197         }
198
199         /* free up our allocated buffer */
200         usb_buffer_free(urb->dev, urb->transfer_buffer_length,
201                         urb->transfer_buffer, urb->transfer_dma);
202         up(&dev->limit_sem);
203 }
204
205 static ssize_t lcd_write(struct file *file, const char __user * user_buffer, size_t count, loff_t *ppos)
206 {
207         struct usb_lcd *dev;
208         int retval = 0, r;
209         struct urb *urb = NULL;
210         char *buf = NULL;
211         
212         dev = (struct usb_lcd *)file->private_data;
213         
214         /* verify that we actually have some data to write */
215         if (count == 0)
216                 goto exit;
217
218         r = down_interruptible(&dev->limit_sem);
219         if (r < 0)
220                 return -EINTR;
221
222         /* create a urb, and a buffer for it, and copy the data to the urb */
223         urb = usb_alloc_urb(0, GFP_KERNEL);
224         if (!urb) {
225                 retval = -ENOMEM;
226                 goto err_no_buf;
227         }
228         
229         buf = usb_buffer_alloc(dev->udev, count, GFP_KERNEL, &urb->transfer_dma);
230         if (!buf) {
231                 retval = -ENOMEM;
232                 goto error;
233         }
234         
235         if (copy_from_user(buf, user_buffer, count)) {
236                 retval = -EFAULT;
237                 goto error;
238         }
239         
240         /* initialize the urb properly */
241         usb_fill_bulk_urb(urb, dev->udev,
242                           usb_sndbulkpipe(dev->udev, dev->bulk_out_endpointAddr),
243                           buf, count, lcd_write_bulk_callback, dev);
244         urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
245
246         usb_anchor_urb(urb, &dev->submitted);
247         
248         /* send the data out the bulk port */
249         retval = usb_submit_urb(urb, GFP_KERNEL);
250         if (retval) {
251                 err("USBLCD: %s - failed submitting write urb, error %d", __func__, retval);
252                 goto error_unanchor;
253         }
254         
255         /* release our reference to this urb, the USB core will eventually free it entirely */
256         usb_free_urb(urb);
257
258 exit:
259         return count;
260 error_unanchor:
261         usb_unanchor_urb(urb);
262 error:
263         usb_buffer_free(dev->udev, count, buf, urb->transfer_dma);
264         usb_free_urb(urb);
265 err_no_buf:
266         up(&dev->limit_sem);
267         return retval;
268 }
269
270 static const struct file_operations lcd_fops = {
271         .owner =        THIS_MODULE,
272         .read =         lcd_read,
273         .write =        lcd_write,
274         .open =         lcd_open,
275         .ioctl =        lcd_ioctl,
276         .release =      lcd_release,
277 };
278
279 /*
280  * usb class driver info in order to get a minor number from the usb core,
281  * and to have the device registered with the driver core
282  */
283 static struct usb_class_driver lcd_class = {
284         .name =         "lcd%d",
285         .fops =         &lcd_fops,
286         .minor_base =   USBLCD_MINOR,
287 };
288
289 static int lcd_probe(struct usb_interface *interface, const struct usb_device_id *id)
290 {
291         struct usb_lcd *dev = NULL;
292         struct usb_host_interface *iface_desc;
293         struct usb_endpoint_descriptor *endpoint;
294         size_t buffer_size;
295         int i;
296         int retval = -ENOMEM;
297
298         /* allocate memory for our device state and initialize it */
299         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
300         if (dev == NULL) {
301                 err("Out of memory");
302                 goto error;
303         }
304         kref_init(&dev->kref);
305         sema_init(&dev->limit_sem, USB_LCD_CONCURRENT_WRITES);
306         init_usb_anchor(&dev->submitted);
307
308         dev->udev = usb_get_dev(interface_to_usbdev(interface));
309         dev->interface = interface;
310
311         if (le16_to_cpu(dev->udev->descriptor.idProduct) != 0x0001) {
312                 warn(KERN_INFO "USBLCD model not supported.");
313                 return -ENODEV;
314         }
315         
316         /* set up the endpoint information */
317         /* use only the first bulk-in and bulk-out endpoints */
318         iface_desc = interface->cur_altsetting;
319         for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
320                 endpoint = &iface_desc->endpoint[i].desc;
321
322                 if (!dev->bulk_in_endpointAddr &&
323                     usb_endpoint_is_bulk_in(endpoint)) {
324                         /* we found a bulk in endpoint */
325                         buffer_size = le16_to_cpu(endpoint->wMaxPacketSize);
326                         dev->bulk_in_size = buffer_size;
327                         dev->bulk_in_endpointAddr = endpoint->bEndpointAddress;
328                         dev->bulk_in_buffer = kmalloc(buffer_size, GFP_KERNEL);
329                         if (!dev->bulk_in_buffer) {
330                                 err("Could not allocate bulk_in_buffer");
331                                 goto error;
332                         }
333                 }
334
335                 if (!dev->bulk_out_endpointAddr &&
336                     usb_endpoint_is_bulk_out(endpoint)) {
337                         /* we found a bulk out endpoint */
338                         dev->bulk_out_endpointAddr = endpoint->bEndpointAddress;
339                 }
340         }
341         if (!(dev->bulk_in_endpointAddr && dev->bulk_out_endpointAddr)) {
342                 err("Could not find both bulk-in and bulk-out endpoints");
343                 goto error;
344         }
345
346         /* save our data pointer in this interface device */
347         usb_set_intfdata(interface, dev);
348
349         /* we can register the device now, as it is ready */
350         retval = usb_register_dev(interface, &lcd_class);
351         if (retval) {
352                 /* something prevented us from registering this driver */
353                 err("Not able to get a minor for this device.");
354                 usb_set_intfdata(interface, NULL);
355                 goto error;
356         }
357
358         i = le16_to_cpu(dev->udev->descriptor.bcdDevice);
359
360         info("USBLCD Version %1d%1d.%1d%1d found at address %d",
361                 (i & 0xF000)>>12,(i & 0xF00)>>8,(i & 0xF0)>>4,(i & 0xF),
362                 dev->udev->devnum);
363
364         /* let the user know what node this device is now attached to */
365         info("USB LCD device now attached to USBLCD-%d", interface->minor);
366         return 0;
367
368 error:
369         if (dev)
370                 kref_put(&dev->kref, lcd_delete);
371         return retval;
372 }
373
374 static void lcd_draw_down(struct usb_lcd *dev)
375 {
376         int time;
377
378         time = usb_wait_anchor_empty_timeout(&dev->submitted, 1000);
379         if (!time)
380                 usb_kill_anchored_urbs(&dev->submitted);
381 }
382
383 static int lcd_suspend(struct usb_interface *intf, pm_message_t message)
384 {
385         struct usb_lcd *dev = usb_get_intfdata(intf);
386
387         if (!dev)
388                 return 0;
389         lcd_draw_down(dev);
390         return 0;
391 }
392
393 static int lcd_resume (struct usb_interface *intf)
394 {
395         return 0;
396 }
397
398 static void lcd_disconnect(struct usb_interface *interface)
399 {
400         struct usb_lcd *dev;
401         int minor = interface->minor;
402
403         mutex_lock(&open_disc_mutex);
404         dev = usb_get_intfdata(interface);
405         usb_set_intfdata(interface, NULL);
406         mutex_unlock(&open_disc_mutex);
407
408         /* give back our minor */
409         usb_deregister_dev(interface, &lcd_class);
410  
411         /* decrement our usage count */
412         kref_put(&dev->kref, lcd_delete);
413
414         info("USB LCD #%d now disconnected", minor);
415 }
416
417 static struct usb_driver lcd_driver = {
418         .name =         "usblcd",
419         .probe =        lcd_probe,
420         .disconnect =   lcd_disconnect,
421         .suspend =      lcd_suspend,
422         .resume =       lcd_resume,
423         .id_table =     id_table,
424         .supports_autosuspend = 1,
425 };
426
427 static int __init usb_lcd_init(void)
428 {
429         int result;
430         
431         result = usb_register(&lcd_driver);
432         if (result)
433                 err("usb_register failed. Error number %d", result);
434
435         return result;
436 }
437
438
439 static void __exit usb_lcd_exit(void)
440 {
441         usb_deregister(&lcd_driver);
442 }
443
444 module_init(usb_lcd_init);
445 module_exit(usb_lcd_exit);
446
447 MODULE_AUTHOR("Georges Toth <g.toth@e-biz.lu>");
448 MODULE_DESCRIPTION(DRIVER_VERSION);
449 MODULE_LICENSE("GPL");