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 <asm/uaccess.h>
21 #include <linux/usb.h>
23 #define DRIVER_VERSION "USBLCD Driver Version 1.05"
25 #define USBLCD_MINOR 144
27 #define IOCTL_GET_HARD_VERSION 1
28 #define IOCTL_GET_DRV_VERSION 2
31 static struct usb_device_id id_table [] = {
32 { .idVendor = 0x10D2, .match_flags = USB_DEVICE_ID_MATCH_VENDOR, },
35 MODULE_DEVICE_TABLE (usb, id_table);
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 */
47 #define to_lcd_dev(d) container_of(d, struct usb_lcd, kref)
49 static struct usb_driver lcd_driver;
52 static void lcd_delete(struct kref *kref)
54 struct usb_lcd *dev = to_lcd_dev(kref);
56 usb_put_dev(dev->udev);
57 kfree (dev->bulk_in_buffer);
62 static int lcd_open(struct inode *inode, struct file *file)
65 struct usb_interface *interface;
69 subminor = iminor(inode);
71 interface = usb_find_interface(&lcd_driver, subminor);
73 err ("USBLCD: %s - error, can't find device for minor %d",
74 __FUNCTION__, subminor);
79 dev = usb_get_intfdata(interface);
85 /* increment our usage count for the device */
88 /* save our object in the file's private structure */
89 file->private_data = dev;
95 static int lcd_release(struct inode *inode, struct file *file)
99 dev = (struct usb_lcd *)file->private_data;
103 /* decrement the count on our device */
104 kref_put(&dev->kref, lcd_delete);
108 static ssize_t lcd_read(struct file *file, char __user * buffer, size_t count, loff_t *ppos)
114 dev = (struct usb_lcd *)file->private_data;
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),
120 min(dev->bulk_in_size, count),
123 /* if the read was successful, copy the data to userspace */
125 if (copy_to_user(buffer, dev->bulk_in_buffer, bytes_read))
134 static int lcd_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
140 dev = (struct usb_lcd *)file->private_data;
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,
152 if (copy_to_user((void __user *)arg,buf,strlen(buf))!=0)
155 case IOCTL_GET_DRV_VERSION:
156 sprintf(buf,DRIVER_VERSION);
157 if (copy_to_user((void __user *)arg,buf,strlen(buf))!=0)
168 static void lcd_write_bulk_callback(struct urb *urb)
172 dev = (struct usb_lcd *)urb->context;
174 /* sync/async unlink faults aren't errors */
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);
183 /* free up our allocated buffer */
184 usb_buffer_free(urb->dev, urb->transfer_buffer_length,
185 urb->transfer_buffer, urb->transfer_dma);
188 static ssize_t lcd_write(struct file *file, const char __user * user_buffer, size_t count, loff_t *ppos)
192 struct urb *urb = NULL;
195 dev = (struct usb_lcd *)file->private_data;
197 /* verify that we actually have some data to write */
201 /* create a urb, and a buffer for it, and copy the data to the urb */
202 urb = usb_alloc_urb(0, GFP_KERNEL);
206 buf = usb_buffer_alloc(dev->udev, count, GFP_KERNEL, &urb->transfer_dma);
212 if (copy_from_user(buf, user_buffer, count)) {
217 /* initialize the urb properly */
218 usb_fill_bulk_urb(urb, dev->udev,
219 usb_sndbulkpipe(dev->udev, dev->bulk_out_endpointAddr),
220 buf, count, lcd_write_bulk_callback, dev);
221 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
223 /* send the data out the bulk port */
224 retval = usb_submit_urb(urb, GFP_KERNEL);
226 err("USBLCD: %s - failed submitting write urb, error %d", __FUNCTION__, retval);
230 /* release our reference to this urb, the USB core will eventually free it entirely */
237 usb_buffer_free(dev->udev, count, buf, urb->transfer_dma);
242 static const struct file_operations lcd_fops = {
243 .owner = THIS_MODULE,
248 .release = lcd_release,
252 * usb class driver info in order to get a minor number from the usb core,
253 * and to have the device registered with the driver core
255 static struct usb_class_driver lcd_class = {
258 .minor_base = USBLCD_MINOR,
261 static int lcd_probe(struct usb_interface *interface, const struct usb_device_id *id)
263 struct usb_lcd *dev = NULL;
264 struct usb_host_interface *iface_desc;
265 struct usb_endpoint_descriptor *endpoint;
268 int retval = -ENOMEM;
270 /* allocate memory for our device state and initialize it */
271 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
273 err("Out of memory");
276 kref_init(&dev->kref);
278 dev->udev = usb_get_dev(interface_to_usbdev(interface));
279 dev->interface = interface;
281 if (le16_to_cpu(dev->udev->descriptor.idProduct) != 0x0001) {
282 warn(KERN_INFO "USBLCD model not supported.");
286 /* set up the endpoint information */
287 /* use only the first bulk-in and bulk-out endpoints */
288 iface_desc = interface->cur_altsetting;
289 for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
290 endpoint = &iface_desc->endpoint[i].desc;
292 if (!dev->bulk_in_endpointAddr &&
293 usb_endpoint_is_bulk_in(endpoint)) {
294 /* we found a bulk in endpoint */
295 buffer_size = le16_to_cpu(endpoint->wMaxPacketSize);
296 dev->bulk_in_size = buffer_size;
297 dev->bulk_in_endpointAddr = endpoint->bEndpointAddress;
298 dev->bulk_in_buffer = kmalloc(buffer_size, GFP_KERNEL);
299 if (!dev->bulk_in_buffer) {
300 err("Could not allocate bulk_in_buffer");
305 if (!dev->bulk_out_endpointAddr &&
306 usb_endpoint_is_bulk_out(endpoint)) {
307 /* we found a bulk out endpoint */
308 dev->bulk_out_endpointAddr = endpoint->bEndpointAddress;
311 if (!(dev->bulk_in_endpointAddr && dev->bulk_out_endpointAddr)) {
312 err("Could not find both bulk-in and bulk-out endpoints");
316 /* save our data pointer in this interface device */
317 usb_set_intfdata(interface, dev);
319 /* we can register the device now, as it is ready */
320 retval = usb_register_dev(interface, &lcd_class);
322 /* something prevented us from registering this driver */
323 err("Not able to get a minor for this device.");
324 usb_set_intfdata(interface, NULL);
328 i = le16_to_cpu(dev->udev->descriptor.bcdDevice);
330 info("USBLCD Version %1d%1d.%1d%1d found at address %d",
331 (i & 0xF000)>>12,(i & 0xF00)>>8,(i & 0xF0)>>4,(i & 0xF),
334 /* let the user know what node this device is now attached to */
335 info("USB LCD device now attached to USBLCD-%d", interface->minor);
340 kref_put(&dev->kref, lcd_delete);
344 static void lcd_disconnect(struct usb_interface *interface)
347 int minor = interface->minor;
349 /* prevent skel_open() from racing skel_disconnect() */
352 dev = usb_get_intfdata(interface);
353 usb_set_intfdata(interface, NULL);
355 /* give back our minor */
356 usb_deregister_dev(interface, &lcd_class);
360 /* decrement our usage count */
361 kref_put(&dev->kref, lcd_delete);
363 info("USB LCD #%d now disconnected", minor);
366 static struct usb_driver lcd_driver = {
369 .disconnect = lcd_disconnect,
370 .id_table = id_table,
373 static int __init usb_lcd_init(void)
377 result = usb_register(&lcd_driver);
379 err("usb_register failed. Error number %d", result);
385 static void __exit usb_lcd_exit(void)
387 usb_deregister(&lcd_driver);
390 module_init(usb_lcd_init);
391 module_exit(usb_lcd_exit);
393 MODULE_AUTHOR("Georges Toth <g.toth@e-biz.lu>");
394 MODULE_DESCRIPTION(DRIVER_VERSION);
395 MODULE_LICENSE("GPL");