1 /*****************************************************************************
2 * USBLCD Kernel Driver *
4 * (C) 2005 Georges Toth <g.toth@e-biz.lu> *
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) *
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>
24 #define DRIVER_VERSION "USBLCD Driver Version 1.05"
26 #define USBLCD_MINOR 144
28 #define IOCTL_GET_HARD_VERSION 1
29 #define IOCTL_GET_DRV_VERSION 2
32 static DEFINE_MUTEX(lcd_mutex);
33 static const struct usb_device_id id_table[] = {
34 { .idVendor = 0x10D2, .match_flags = USB_DEVICE_ID_MATCH_VENDOR, },
37 MODULE_DEVICE_TABLE (usb, id_table);
39 static DEFINE_MUTEX(open_disc_mutex);
43 struct usb_device * udev; /* init: probe_lcd */
44 struct usb_interface * interface; /* the interface for this device */
45 unsigned char * bulk_in_buffer; /* the buffer to receive data */
46 size_t bulk_in_size; /* the size of the receive buffer */
47 __u8 bulk_in_endpointAddr; /* the address of the bulk in endpoint */
48 __u8 bulk_out_endpointAddr; /* the address of the bulk out endpoint */
50 struct semaphore limit_sem; /* to stop writes at full throttle from
52 struct usb_anchor submitted; /* URBs to wait for before suspend */
54 #define to_lcd_dev(d) container_of(d, struct usb_lcd, kref)
56 #define USB_LCD_CONCURRENT_WRITES 5
58 static struct usb_driver lcd_driver;
61 static void lcd_delete(struct kref *kref)
63 struct usb_lcd *dev = to_lcd_dev(kref);
65 usb_put_dev(dev->udev);
66 kfree (dev->bulk_in_buffer);
71 static int lcd_open(struct inode *inode, struct file *file)
74 struct usb_interface *interface;
77 mutex_lock(&lcd_mutex);
78 subminor = iminor(inode);
80 interface = usb_find_interface(&lcd_driver, subminor);
82 mutex_unlock(&lcd_mutex);
83 err ("USBLCD: %s - error, can't find device for minor %d",
88 mutex_lock(&open_disc_mutex);
89 dev = usb_get_intfdata(interface);
91 mutex_unlock(&open_disc_mutex);
92 mutex_unlock(&lcd_mutex);
96 /* increment our usage count for the device */
98 mutex_unlock(&open_disc_mutex);
100 /* grab a power reference */
101 r = usb_autopm_get_interface(interface);
103 kref_put(&dev->kref, lcd_delete);
104 mutex_unlock(&lcd_mutex);
108 /* save our object in the file's private structure */
109 file->private_data = dev;
110 mutex_unlock(&lcd_mutex);
115 static int lcd_release(struct inode *inode, struct file *file)
119 dev = file->private_data;
123 /* decrement the count on our device */
124 usb_autopm_put_interface(dev->interface);
125 kref_put(&dev->kref, lcd_delete);
129 static ssize_t lcd_read(struct file *file, char __user * buffer, size_t count, loff_t *ppos)
135 dev = file->private_data;
137 /* do a blocking bulk read to get data from the device */
138 retval = usb_bulk_msg(dev->udev,
139 usb_rcvbulkpipe(dev->udev, dev->bulk_in_endpointAddr),
141 min(dev->bulk_in_size, count),
144 /* if the read was successful, copy the data to userspace */
146 if (copy_to_user(buffer, dev->bulk_in_buffer, bytes_read))
155 static long lcd_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
161 dev = file->private_data;
166 case IOCTL_GET_HARD_VERSION:
167 mutex_lock(&lcd_mutex);
168 bcdDevice = le16_to_cpu((dev->udev)->descriptor.bcdDevice);
169 sprintf(buf,"%1d%1d.%1d%1d",
170 (bcdDevice & 0xF000)>>12,
171 (bcdDevice & 0xF00)>>8,
172 (bcdDevice & 0xF0)>>4,
174 mutex_unlock(&lcd_mutex);
175 if (copy_to_user((void __user *)arg,buf,strlen(buf))!=0)
178 case IOCTL_GET_DRV_VERSION:
179 sprintf(buf,DRIVER_VERSION);
180 if (copy_to_user((void __user *)arg,buf,strlen(buf))!=0)
191 static void lcd_write_bulk_callback(struct urb *urb)
194 int status = urb->status;
198 /* sync/async unlink faults aren't errors */
200 !(status == -ENOENT ||
201 status == -ECONNRESET ||
202 status == -ESHUTDOWN)) {
203 dbg("USBLCD: %s - nonzero write bulk status received: %d",
207 /* free up our allocated buffer */
208 usb_free_coherent(urb->dev, urb->transfer_buffer_length,
209 urb->transfer_buffer, urb->transfer_dma);
213 static ssize_t lcd_write(struct file *file, const char __user * user_buffer, size_t count, loff_t *ppos)
217 struct urb *urb = NULL;
220 dev = file->private_data;
222 /* verify that we actually have some data to write */
226 r = down_interruptible(&dev->limit_sem);
230 /* create a urb, and a buffer for it, and copy the data to the urb */
231 urb = usb_alloc_urb(0, GFP_KERNEL);
237 buf = usb_alloc_coherent(dev->udev, count, GFP_KERNEL, &urb->transfer_dma);
243 if (copy_from_user(buf, user_buffer, count)) {
248 /* initialize the urb properly */
249 usb_fill_bulk_urb(urb, dev->udev,
250 usb_sndbulkpipe(dev->udev, dev->bulk_out_endpointAddr),
251 buf, count, lcd_write_bulk_callback, dev);
252 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
254 usb_anchor_urb(urb, &dev->submitted);
256 /* send the data out the bulk port */
257 retval = usb_submit_urb(urb, GFP_KERNEL);
259 err("USBLCD: %s - failed submitting write urb, error %d", __func__, retval);
263 /* release our reference to this urb, the USB core will eventually free it entirely */
269 usb_unanchor_urb(urb);
271 usb_free_coherent(dev->udev, count, buf, urb->transfer_dma);
278 static const struct file_operations lcd_fops = {
279 .owner = THIS_MODULE,
283 .unlocked_ioctl = lcd_ioctl,
284 .release = lcd_release,
285 .llseek = noop_llseek,
289 * usb class driver info in order to get a minor number from the usb core,
290 * and to have the device registered with the driver core
292 static struct usb_class_driver lcd_class = {
295 .minor_base = USBLCD_MINOR,
298 static int lcd_probe(struct usb_interface *interface, const struct usb_device_id *id)
300 struct usb_lcd *dev = NULL;
301 struct usb_host_interface *iface_desc;
302 struct usb_endpoint_descriptor *endpoint;
305 int retval = -ENOMEM;
307 /* allocate memory for our device state and initialize it */
308 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
310 err("Out of memory");
313 kref_init(&dev->kref);
314 sema_init(&dev->limit_sem, USB_LCD_CONCURRENT_WRITES);
315 init_usb_anchor(&dev->submitted);
317 dev->udev = usb_get_dev(interface_to_usbdev(interface));
318 dev->interface = interface;
320 if (le16_to_cpu(dev->udev->descriptor.idProduct) != 0x0001) {
321 dev_warn(&interface->dev, "USBLCD model not supported.\n");
326 /* set up the endpoint information */
327 /* use only the first bulk-in and bulk-out endpoints */
328 iface_desc = interface->cur_altsetting;
329 for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
330 endpoint = &iface_desc->endpoint[i].desc;
332 if (!dev->bulk_in_endpointAddr &&
333 usb_endpoint_is_bulk_in(endpoint)) {
334 /* we found a bulk in endpoint */
335 buffer_size = le16_to_cpu(endpoint->wMaxPacketSize);
336 dev->bulk_in_size = buffer_size;
337 dev->bulk_in_endpointAddr = endpoint->bEndpointAddress;
338 dev->bulk_in_buffer = kmalloc(buffer_size, GFP_KERNEL);
339 if (!dev->bulk_in_buffer) {
340 err("Could not allocate bulk_in_buffer");
345 if (!dev->bulk_out_endpointAddr &&
346 usb_endpoint_is_bulk_out(endpoint)) {
347 /* we found a bulk out endpoint */
348 dev->bulk_out_endpointAddr = endpoint->bEndpointAddress;
351 if (!(dev->bulk_in_endpointAddr && dev->bulk_out_endpointAddr)) {
352 err("Could not find both bulk-in and bulk-out endpoints");
356 /* save our data pointer in this interface device */
357 usb_set_intfdata(interface, dev);
359 /* we can register the device now, as it is ready */
360 retval = usb_register_dev(interface, &lcd_class);
362 /* something prevented us from registering this driver */
363 err("Not able to get a minor for this device.");
364 usb_set_intfdata(interface, NULL);
368 i = le16_to_cpu(dev->udev->descriptor.bcdDevice);
370 dev_info(&interface->dev, "USBLCD Version %1d%1d.%1d%1d found "
371 "at address %d\n", (i & 0xF000)>>12, (i & 0xF00)>>8,
372 (i & 0xF0)>>4,(i & 0xF), dev->udev->devnum);
374 /* let the user know what node this device is now attached to */
375 dev_info(&interface->dev, "USB LCD device now attached to USBLCD-%d\n",
381 kref_put(&dev->kref, lcd_delete);
385 static void lcd_draw_down(struct usb_lcd *dev)
389 time = usb_wait_anchor_empty_timeout(&dev->submitted, 1000);
391 usb_kill_anchored_urbs(&dev->submitted);
394 static int lcd_suspend(struct usb_interface *intf, pm_message_t message)
396 struct usb_lcd *dev = usb_get_intfdata(intf);
404 static int lcd_resume (struct usb_interface *intf)
409 static void lcd_disconnect(struct usb_interface *interface)
412 int minor = interface->minor;
414 mutex_lock(&open_disc_mutex);
415 dev = usb_get_intfdata(interface);
416 usb_set_intfdata(interface, NULL);
417 mutex_unlock(&open_disc_mutex);
419 /* give back our minor */
420 usb_deregister_dev(interface, &lcd_class);
422 /* decrement our usage count */
423 kref_put(&dev->kref, lcd_delete);
425 dev_info(&interface->dev, "USB LCD #%d now disconnected\n", minor);
428 static struct usb_driver lcd_driver = {
431 .disconnect = lcd_disconnect,
432 .suspend = lcd_suspend,
433 .resume = lcd_resume,
434 .id_table = id_table,
435 .supports_autosuspend = 1,
438 static int __init usb_lcd_init(void)
442 result = usb_register(&lcd_driver);
444 err("usb_register failed. Error number %d", result);
450 static void __exit usb_lcd_exit(void)
452 usb_deregister(&lcd_driver);
455 module_init(usb_lcd_init);
456 module_exit(usb_lcd_exit);
458 MODULE_AUTHOR("Georges Toth <g.toth@e-biz.lu>");
459 MODULE_DESCRIPTION(DRIVER_VERSION);
460 MODULE_LICENSE("GPL");