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