85f3725334b017a48c8ca5c0129becf0f97d8add
[linux-2.6.git] / 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 <asm/uaccess.h>
21 #include <linux/usb.h>
22
23 #define DRIVER_VERSION "USBLCD Driver Version 1.05"
24
25 #define USBLCD_MINOR            144
26
27 #define IOCTL_GET_HARD_VERSION  1
28 #define IOCTL_GET_DRV_VERSION   2
29
30
31 static struct usb_device_id id_table [] = {
32         { .idVendor = 0x10D2, .match_flags = USB_DEVICE_ID_MATCH_VENDOR, },
33         { },
34 };
35 MODULE_DEVICE_TABLE (usb, id_table);
36
37
38 struct usb_lcd {
39         struct usb_device *     udev;                   /* init: probe_lcd */
40         struct usb_interface *  interface;              /* the interface for this device */
41         unsigned char *         bulk_in_buffer;         /* the buffer to receive data */
42         size_t                  bulk_in_size;           /* the size of the receive buffer */
43         __u8                    bulk_in_endpointAddr;   /* the address of the bulk in endpoint */
44         __u8                    bulk_out_endpointAddr;  /* the address of the bulk out endpoint */
45         struct kref             kref;
46 };
47 #define to_lcd_dev(d) container_of(d, struct usb_lcd, kref)
48
49 static struct usb_driver lcd_driver;
50
51
52 static void lcd_delete(struct kref *kref)
53 {
54         struct usb_lcd *dev = to_lcd_dev(kref);
55
56         usb_put_dev(dev->udev);
57         kfree (dev->bulk_in_buffer);
58         kfree (dev);
59 }
60
61
62 static int lcd_open(struct inode *inode, struct file *file)
63 {
64         struct usb_lcd *dev;
65         struct usb_interface *interface;
66         int subminor;
67         int retval = 0;
68
69         subminor = iminor(inode);
70
71         interface = usb_find_interface(&lcd_driver, subminor);
72         if (!interface) {
73                 err ("USBLCD: %s - error, can't find device for minor %d",
74                      __FUNCTION__, subminor);
75                 retval = -ENODEV;
76                 goto exit;
77         }
78
79         dev = usb_get_intfdata(interface);
80         if (!dev) {
81                 retval = -ENODEV;
82                 goto exit;
83         }
84
85         /* increment our usage count for the device */
86         kref_get(&dev->kref);
87
88         /* save our object in the file's private structure */
89         file->private_data = dev;
90
91 exit:
92         return retval;
93 }
94
95 static int lcd_release(struct inode *inode, struct file *file)
96 {
97         struct usb_lcd *dev;
98
99         dev = (struct usb_lcd *)file->private_data;
100         if (dev == NULL)
101                 return -ENODEV;
102
103         /* decrement the count on our device */
104         kref_put(&dev->kref, lcd_delete);
105         return 0;
106 }
107
108 static ssize_t lcd_read(struct file *file, char __user * buffer, size_t count, loff_t *ppos)
109 {
110         struct usb_lcd *dev;
111         int retval = 0;
112         int bytes_read;
113
114         dev = (struct usb_lcd *)file->private_data;
115
116         /* do a blocking bulk read to get data from the device */
117         retval = usb_bulk_msg(dev->udev, 
118                               usb_rcvbulkpipe(dev->udev, dev->bulk_in_endpointAddr),
119                               dev->bulk_in_buffer,
120                               min(dev->bulk_in_size, count),
121                               &bytes_read, 10000);
122
123         /* if the read was successful, copy the data to userspace */
124         if (!retval) {
125                 if (copy_to_user(buffer, dev->bulk_in_buffer, bytes_read))
126                         retval = -EFAULT;
127                 else
128                         retval = bytes_read;
129         }
130
131         return retval;
132 }
133
134 static int lcd_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
135 {
136         struct usb_lcd *dev;
137         u16 bcdDevice;
138         char buf[30];
139
140         dev = (struct usb_lcd *)file->private_data;
141         if (dev == NULL)
142                 return -ENODEV;
143         
144         switch (cmd) {
145         case IOCTL_GET_HARD_VERSION:
146                 bcdDevice = le16_to_cpu((dev->udev)->descriptor.bcdDevice);
147                 sprintf(buf,"%1d%1d.%1d%1d",
148                         (bcdDevice & 0xF000)>>12,
149                         (bcdDevice & 0xF00)>>8,
150                         (bcdDevice & 0xF0)>>4,
151                         (bcdDevice & 0xF));
152                 if (copy_to_user((void __user *)arg,buf,strlen(buf))!=0)
153                         return -EFAULT;
154                 break;
155         case IOCTL_GET_DRV_VERSION:
156                 sprintf(buf,DRIVER_VERSION);
157                 if (copy_to_user((void __user *)arg,buf,strlen(buf))!=0)
158                         return -EFAULT;
159                 break;
160         default:
161                 return -ENOTTY;
162                 break;
163         }
164
165         return 0;
166 }
167
168 static void lcd_write_bulk_callback(struct urb *urb, struct pt_regs *regs)
169 {
170         struct usb_lcd *dev;
171
172         dev = (struct usb_lcd *)urb->context;
173
174         /* sync/async unlink faults aren't errors */
175         if (urb->status &&
176             !(urb->status == -ENOENT ||
177               urb->status == -ECONNRESET ||
178               urb->status == -ESHUTDOWN)) {
179                 dbg("USBLCD: %s - nonzero write bulk status received: %d",
180                     __FUNCTION__, urb->status);
181         }
182
183         /* free up our allocated buffer */
184         usb_buffer_free(urb->dev, urb->transfer_buffer_length,
185                         urb->transfer_buffer, urb->transfer_dma);
186 }
187
188 static ssize_t lcd_write(struct file *file, const char __user * user_buffer, size_t count, loff_t *ppos)
189 {
190         struct usb_lcd *dev;
191         int retval = 0;
192         struct urb *urb = NULL;
193         char *buf = NULL;
194         
195         dev = (struct usb_lcd *)file->private_data;
196         
197         /* verify that we actually have some data to write */
198         if (count == 0)
199                 goto exit;
200
201         /* create a urb, and a buffer for it, and copy the data to the urb */
202         urb = usb_alloc_urb(0, GFP_KERNEL);
203         if (!urb) {
204                 retval = -ENOMEM;
205                 goto error;
206         }
207         
208         buf = usb_buffer_alloc(dev->udev, count, GFP_KERNEL, &urb->transfer_dma);
209         if (!buf) {
210                 retval = -ENOMEM;
211                 goto error;
212         }
213         
214         if (copy_from_user(buf, user_buffer, count)) {
215                 retval = -EFAULT;
216                 goto error;
217         }
218         
219         /* initialize the urb properly */
220         usb_fill_bulk_urb(urb, dev->udev,
221                           usb_sndbulkpipe(dev->udev, dev->bulk_out_endpointAddr),
222                           buf, count, lcd_write_bulk_callback, dev);
223         urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
224         
225         /* send the data out the bulk port */
226         retval = usb_submit_urb(urb, GFP_KERNEL);
227         if (retval) {
228                 err("USBLCD: %s - failed submitting write urb, error %d", __FUNCTION__, retval);
229                 goto error;
230         }
231         
232         /* release our reference to this urb, the USB core will eventually free it entirely */
233         usb_free_urb(urb);
234
235 exit:
236         return count;
237
238 error:
239         usb_buffer_free(dev->udev, count, buf, urb->transfer_dma);
240         usb_free_urb(urb);
241         return retval;
242 }
243
244 static struct file_operations lcd_fops = {
245         .owner =        THIS_MODULE,
246         .read =         lcd_read,
247         .write =        lcd_write,
248         .open =         lcd_open,
249         .ioctl =        lcd_ioctl,
250         .release =      lcd_release,
251 };
252
253 /*
254  * usb class driver info in order to get a minor number from the usb core,
255  * and to have the device registered with the driver core
256  */
257 static struct usb_class_driver lcd_class = {
258         .name =         "lcd%d",
259         .fops =         &lcd_fops,
260         .minor_base =   USBLCD_MINOR,
261 };
262
263 static int lcd_probe(struct usb_interface *interface, const struct usb_device_id *id)
264 {
265         struct usb_lcd *dev = NULL;
266         struct usb_host_interface *iface_desc;
267         struct usb_endpoint_descriptor *endpoint;
268         size_t buffer_size;
269         int i;
270         int retval = -ENOMEM;
271
272         /* allocate memory for our device state and initialize it */
273         dev = kmalloc(sizeof(*dev), GFP_KERNEL);
274         if (dev == NULL) {
275                 err("Out of memory");
276                 goto error;
277         }
278         memset(dev, 0x00, sizeof(*dev));
279         kref_init(&dev->kref);
280
281         dev->udev = usb_get_dev(interface_to_usbdev(interface));
282         dev->interface = interface;
283
284         if (le16_to_cpu(dev->udev->descriptor.idProduct) != 0x0001) {
285                 warn(KERN_INFO "USBLCD model not supported.");
286                 return -ENODEV;
287         }
288         
289         /* set up the endpoint information */
290         /* use only the first bulk-in and bulk-out endpoints */
291         iface_desc = interface->cur_altsetting;
292         for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
293                 endpoint = &iface_desc->endpoint[i].desc;
294
295                 if (!dev->bulk_in_endpointAddr &&
296                     (endpoint->bEndpointAddress & USB_DIR_IN) &&
297                     ((endpoint->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK)
298                                         == USB_ENDPOINT_XFER_BULK)) {
299                         /* we found a bulk in endpoint */
300                         buffer_size = le16_to_cpu(endpoint->wMaxPacketSize);
301                         dev->bulk_in_size = buffer_size;
302                         dev->bulk_in_endpointAddr = endpoint->bEndpointAddress;
303                         dev->bulk_in_buffer = kmalloc(buffer_size, GFP_KERNEL);
304                         if (!dev->bulk_in_buffer) {
305                                 err("Could not allocate bulk_in_buffer");
306                                 goto error;
307                         }
308                 }
309
310                 if (!dev->bulk_out_endpointAddr &&
311                     !(endpoint->bEndpointAddress & USB_DIR_IN) &&
312                     ((endpoint->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK)
313                                         == USB_ENDPOINT_XFER_BULK)) {
314                         /* we found a bulk out endpoint */
315                         dev->bulk_out_endpointAddr = endpoint->bEndpointAddress;
316                 }
317         }
318         if (!(dev->bulk_in_endpointAddr && dev->bulk_out_endpointAddr)) {
319                 err("Could not find both bulk-in and bulk-out endpoints");
320                 goto error;
321         }
322
323         /* save our data pointer in this interface device */
324         usb_set_intfdata(interface, dev);
325
326         /* we can register the device now, as it is ready */
327         retval = usb_register_dev(interface, &lcd_class);
328         if (retval) {
329                 /* something prevented us from registering this driver */
330                 err("Not able to get a minor for this device.");
331                 usb_set_intfdata(interface, NULL);
332                 goto error;
333         }
334
335         i = le16_to_cpu(dev->udev->descriptor.bcdDevice);
336
337         info("USBLCD Version %1d%1d.%1d%1d found at address %d",
338                 (i & 0xF000)>>12,(i & 0xF00)>>8,(i & 0xF0)>>4,(i & 0xF),
339                 dev->udev->devnum);
340
341         /* let the user know what node this device is now attached to */
342         info("USB LCD device now attached to USBLCD-%d", interface->minor);
343         return 0;
344
345 error:
346         if (dev)
347                 kref_put(&dev->kref, lcd_delete);
348         return retval;
349 }
350
351 static void lcd_disconnect(struct usb_interface *interface)
352 {
353         struct usb_lcd *dev;
354         int minor = interface->minor;
355
356         /* prevent skel_open() from racing skel_disconnect() */
357         lock_kernel();
358
359         dev = usb_get_intfdata(interface);
360         usb_set_intfdata(interface, NULL);
361
362         /* give back our minor */
363         usb_deregister_dev(interface, &lcd_class);
364  
365         unlock_kernel();
366
367         /* decrement our usage count */
368         kref_put(&dev->kref, lcd_delete);
369
370         info("USB LCD #%d now disconnected", minor);
371 }
372
373 static struct usb_driver lcd_driver = {
374         .owner =        THIS_MODULE,
375         .name =         "usblcd",
376         .probe =        lcd_probe,
377         .disconnect =   lcd_disconnect,
378         .id_table =     id_table,
379 };
380
381 static int __init usb_lcd_init(void)
382 {
383         int result;
384         
385         result = usb_register(&lcd_driver);
386         if (result)
387                 err("usb_register failed. Error number %d", result);
388
389         return result;
390 }
391
392
393 static void __exit usb_lcd_exit(void)
394 {
395         usb_deregister(&lcd_driver);
396 }
397
398 module_init(usb_lcd_init);
399 module_exit(usb_lcd_exit);
400
401 MODULE_AUTHOR("Georges Toth <g.toth@e-biz.lu>");
402 MODULE_DESCRIPTION(DRIVER_VERSION);
403 MODULE_LICENSE("GPL");