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v3.1
 
  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
 32static DEFINE_MUTEX(lcd_mutex);
 33static const struct usb_device_id id_table[] = {
 34	{ .idVendor = 0x10D2, .match_flags = USB_DEVICE_ID_MATCH_VENDOR, },
 35	{ },
 36};
 37MODULE_DEVICE_TABLE (usb, id_table);
 38
 39static DEFINE_MUTEX(open_disc_mutex);
 40
 41
 42struct usb_lcd {
 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 */
 
 
 
 
 
 49	struct kref		kref;
 50	struct semaphore	limit_sem;		/* to stop writes at full throttle from
 51							 * using up all RAM */
 52	struct usb_anchor	submitted;		/* URBs to wait for before suspend */
 
 
 53};
 54#define to_lcd_dev(d) container_of(d, struct usb_lcd, kref)
 55
 56#define USB_LCD_CONCURRENT_WRITES	5
 57
 58static struct usb_driver lcd_driver;
 59
 60
 61static void lcd_delete(struct kref *kref)
 62{
 63	struct usb_lcd *dev = to_lcd_dev(kref);
 64
 65	usb_put_dev(dev->udev);
 66	kfree (dev->bulk_in_buffer);
 67	kfree (dev);
 68}
 69
 70
 71static int lcd_open(struct inode *inode, struct file *file)
 72{
 73	struct usb_lcd *dev;
 74	struct usb_interface *interface;
 75	int subminor, r;
 76
 77	mutex_lock(&lcd_mutex);
 78	subminor = iminor(inode);
 79
 80	interface = usb_find_interface(&lcd_driver, subminor);
 81	if (!interface) {
 82		mutex_unlock(&lcd_mutex);
 83		err ("USBLCD: %s - error, can't find device for minor %d",
 84		     __func__, subminor);
 85		return -ENODEV;
 86	}
 87
 88	mutex_lock(&open_disc_mutex);
 89	dev = usb_get_intfdata(interface);
 90	if (!dev) {
 91		mutex_unlock(&open_disc_mutex);
 92		mutex_unlock(&lcd_mutex);
 93		return -ENODEV;
 94	}
 95
 96	/* increment our usage count for the device */
 97	kref_get(&dev->kref);
 98	mutex_unlock(&open_disc_mutex);
 99
100	/* grab a power reference */
101	r = usb_autopm_get_interface(interface);
102	if (r < 0) {
103		kref_put(&dev->kref, lcd_delete);
104		mutex_unlock(&lcd_mutex);
105		return r;
106	}
107
108	/* save our object in the file's private structure */
109	file->private_data = dev;
110	mutex_unlock(&lcd_mutex);
111
112	return 0;
113}
114
115static int lcd_release(struct inode *inode, struct file *file)
116{
117	struct usb_lcd *dev;
118
119	dev = file->private_data;
120	if (dev == NULL)
121		return -ENODEV;
122
123	/* decrement the count on our device */
124	usb_autopm_put_interface(dev->interface);
125	kref_put(&dev->kref, lcd_delete);
126	return 0;
127}
128
129static ssize_t lcd_read(struct file *file, char __user * buffer, size_t count, loff_t *ppos)
 
130{
131	struct usb_lcd *dev;
132	int retval = 0;
133	int bytes_read;
134
135	dev = file->private_data;
136
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),
 
140			      dev->bulk_in_buffer,
141			      min(dev->bulk_in_size, count),
142			      &bytes_read, 10000);
143
144	/* if the read was successful, copy the data to userspace */
145	if (!retval) {
146		if (copy_to_user(buffer, dev->bulk_in_buffer, bytes_read))
147			retval = -EFAULT;
148		else
149			retval = bytes_read;
150	}
151
152	return retval;
153}
154
155static long lcd_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
156{
157	struct usb_lcd *dev;
158	u16 bcdDevice;
159	char buf[30];
160
161	dev = file->private_data;
162	if (dev == NULL)
163		return -ENODEV;
164	
165	switch (cmd) {
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,
173			(bcdDevice & 0xF));
174		mutex_unlock(&lcd_mutex);
175		if (copy_to_user((void __user *)arg,buf,strlen(buf))!=0)
176			return -EFAULT;
177		break;
178	case IOCTL_GET_DRV_VERSION:
179		sprintf(buf,DRIVER_VERSION);
180		if (copy_to_user((void __user *)arg,buf,strlen(buf))!=0)
181			return -EFAULT;
182		break;
183	default:
184		return -ENOTTY;
185		break;
186	}
187
188	return 0;
189}
190
191static void lcd_write_bulk_callback(struct urb *urb)
192{
193	struct usb_lcd *dev;
194	int status = urb->status;
195
196	dev = urb->context;
197
198	/* sync/async unlink faults aren't errors */
199	if (status &&
200	    !(status == -ENOENT ||
201	      status == -ECONNRESET ||
202              status == -ESHUTDOWN)) {
203		dbg("USBLCD: %s - nonzero write bulk status received: %d",
204		    __func__, status);
205	}
206
207	/* free up our allocated buffer */
208	usb_free_coherent(urb->dev, urb->transfer_buffer_length,
209			  urb->transfer_buffer, urb->transfer_dma);
210	up(&dev->limit_sem);
211}
212
213static ssize_t lcd_write(struct file *file, const char __user * user_buffer, size_t count, loff_t *ppos)
 
214{
215	struct usb_lcd *dev;
216        int retval = 0, r;
217	struct urb *urb = NULL;
218	char *buf = NULL;
219	
220	dev = file->private_data;
221	
222	/* verify that we actually have some data to write */
223	if (count == 0)
224		goto exit;
225
226	r = down_interruptible(&dev->limit_sem);
227	if (r < 0)
228		return -EINTR;
229
230	/* create a urb, and a buffer for it, and copy the data to the urb */
231	urb = usb_alloc_urb(0, GFP_KERNEL);
232	if (!urb) {
233		retval = -ENOMEM;
234		goto err_no_buf;
235	}
236	
237	buf = usb_alloc_coherent(dev->udev, count, GFP_KERNEL, &urb->transfer_dma);
 
238	if (!buf) {
239		retval = -ENOMEM;
240		goto error;
241	}
242	
243	if (copy_from_user(buf, user_buffer, count)) {
244		retval = -EFAULT;
245		goto error;
246	}
247	
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;
253
254	usb_anchor_urb(urb, &dev->submitted);
255	
256	/* send the data out the bulk port */
257	retval = usb_submit_urb(urb, GFP_KERNEL);
258	if (retval) {
259		err("USBLCD: %s - failed submitting write urb, error %d", __func__, retval);
 
 
260		goto error_unanchor;
261	}
262	
263	/* release our reference to this urb, the USB core will eventually free it entirely */
 
264	usb_free_urb(urb);
265
266exit:
267	return count;
268error_unanchor:
269	usb_unanchor_urb(urb);
270error:
271	usb_free_coherent(dev->udev, count, buf, urb->transfer_dma);
272	usb_free_urb(urb);
273err_no_buf:
274	up(&dev->limit_sem);
275	return retval;
276}
277
278static const struct file_operations lcd_fops = {
279        .owner =        THIS_MODULE,
280        .read =         lcd_read,
281        .write =        lcd_write,
282        .open =         lcd_open,
283	.unlocked_ioctl = lcd_ioctl,
284        .release =      lcd_release,
285        .llseek =	 noop_llseek,
286};
287
288/*
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
291 */
292static struct usb_class_driver lcd_class = {
293        .name =         "lcd%d",
294        .fops =         &lcd_fops,
295        .minor_base =   USBLCD_MINOR,
296};
297
298static int lcd_probe(struct usb_interface *interface, const struct usb_device_id *id)
 
299{
300	struct usb_lcd *dev = NULL;
301	struct usb_host_interface *iface_desc;
302	struct usb_endpoint_descriptor *endpoint;
303	size_t buffer_size;
304	int i;
305	int retval = -ENOMEM;
306
307	/* allocate memory for our device state and initialize it */
308	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
309	if (dev == NULL) {
310		err("Out of memory");
311		goto error;
312	}
313	kref_init(&dev->kref);
314	sema_init(&dev->limit_sem, USB_LCD_CONCURRENT_WRITES);
315	init_usb_anchor(&dev->submitted);
316
317	dev->udev = usb_get_dev(interface_to_usbdev(interface));
318	dev->interface = interface;
319
320	if (le16_to_cpu(dev->udev->descriptor.idProduct) != 0x0001) {
321		dev_warn(&interface->dev, "USBLCD model not supported.\n");
322		retval = -ENODEV;
323		goto error;
324	}
325	
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;
331
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");
341				goto error;
342			}
343		}
344
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;
349		}
350	}
351	if (!(dev->bulk_in_endpointAddr && dev->bulk_out_endpointAddr)) {
352		err("Could not find both bulk-in and bulk-out endpoints");
 
 
 
 
353		goto error;
354	}
355
 
 
356	/* save our data pointer in this interface device */
357	usb_set_intfdata(interface, dev);
358
359	/* we can register the device now, as it is ready */
360	retval = usb_register_dev(interface, &lcd_class);
361	if (retval) {
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);
365		goto error;
366	}
367
368	i = le16_to_cpu(dev->udev->descriptor.bcdDevice);
369
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);
373
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",
376		 interface->minor);
377	return 0;
378
379error:
380	if (dev)
381		kref_put(&dev->kref, lcd_delete);
382	return retval;
383}
384
385static void lcd_draw_down(struct usb_lcd *dev)
386{
387	int time;
388
389	time = usb_wait_anchor_empty_timeout(&dev->submitted, 1000);
390	if (!time)
391		usb_kill_anchored_urbs(&dev->submitted);
392}
393
394static int lcd_suspend(struct usb_interface *intf, pm_message_t message)
395{
396	struct usb_lcd *dev = usb_get_intfdata(intf);
397
398	if (!dev)
399		return 0;
400	lcd_draw_down(dev);
401	return 0;
402}
403
404static int lcd_resume (struct usb_interface *intf)
405{
406	return 0;
407}
408
409static void lcd_disconnect(struct usb_interface *interface)
410{
411	struct usb_lcd *dev;
412        int minor = interface->minor;
413
414	mutex_lock(&open_disc_mutex);
415        dev = usb_get_intfdata(interface);
416        usb_set_intfdata(interface, NULL);
417	mutex_unlock(&open_disc_mutex);
418
419        /* give back our minor */
420        usb_deregister_dev(interface, &lcd_class);
421 
422	/* decrement our usage count */
423	kref_put(&dev->kref, lcd_delete);
424
425	dev_info(&interface->dev, "USB LCD #%d now disconnected\n", minor);
426}
427
428static struct usb_driver lcd_driver = {
429	.name =		"usblcd",
430	.probe =	lcd_probe,
431	.disconnect =	lcd_disconnect,
432	.suspend =	lcd_suspend,
433	.resume =	lcd_resume,
434	.id_table =	id_table,
435	.supports_autosuspend = 1,
436};
437
438static int __init usb_lcd_init(void)
439{
440	int result;
441	
442	result = usb_register(&lcd_driver);
443	if (result)
444		err("usb_register failed. Error number %d", result);
445
446	return result;
447}
448
449
450static void __exit usb_lcd_exit(void)
451{
452	usb_deregister(&lcd_driver);
453}
454
455module_init(usb_lcd_init);
456module_exit(usb_lcd_exit);
457
458MODULE_AUTHOR("Georges Toth <g.toth@e-biz.lu>");
459MODULE_DESCRIPTION(DRIVER_VERSION);
460MODULE_LICENSE("GPL");
v4.17
  1// SPDX-License-Identifier: GPL-2.0
  2/*****************************************************************************
  3 *                          USBLCD Kernel Driver                             *
  4 *                            Version 1.05                                   *
  5 *             (C) 2005 Georges Toth <g.toth@e-biz.lu>                       *
  6 *                                                                           *
  7 *     This file is licensed under the GPL. See COPYING in the package.      *
  8 * Based on usb-skeleton.c 2.0 by Greg Kroah-Hartman (greg@kroah.com)        *
  9 *                                                                           *
 10 *                                                                           *
 11 * 28.02.05 Complete rewrite of the original usblcd.c driver,                *
 12 *          based on usb_skeleton.c.                                         *
 13 *          This new driver allows more than one USB-LCD to be connected     *
 14 *          and controlled, at once                                          *
 15 *****************************************************************************/
 16#include <linux/module.h>
 17#include <linux/kernel.h>
 
 18#include <linux/slab.h>
 19#include <linux/errno.h>
 20#include <linux/mutex.h>
 21#include <linux/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
 32static DEFINE_MUTEX(lcd_mutex);
 33static const struct usb_device_id id_table[] = {
 34	{ .idVendor = 0x10D2, .match_flags = USB_DEVICE_ID_MATCH_VENDOR, },
 35	{ },
 36};
 37MODULE_DEVICE_TABLE(usb, id_table);
 38
 39static DEFINE_MUTEX(open_disc_mutex);
 40
 41
 42struct usb_lcd {
 43	struct usb_device	*udev;			/* init: probe_lcd */
 44	struct usb_interface	*interface;		/* the interface for
 45							   this device */
 46	unsigned char		*bulk_in_buffer;	/* the buffer to receive
 47							   data */
 48	size_t			bulk_in_size;		/* the size of the
 49							   receive buffer */
 50	__u8			bulk_in_endpointAddr;	/* the address of the
 51							   bulk in endpoint */
 52	__u8			bulk_out_endpointAddr;	/* the address of the
 53							   bulk out endpoint */
 54	struct kref		kref;
 55	struct semaphore	limit_sem;		/* to stop writes at
 56							   full throttle from
 57							   using up all RAM */
 58	struct usb_anchor	submitted;		/* URBs to wait for
 59							   before suspend */
 60};
 61#define to_lcd_dev(d) container_of(d, struct usb_lcd, kref)
 62
 63#define USB_LCD_CONCURRENT_WRITES	5
 64
 65static struct usb_driver lcd_driver;
 66
 67
 68static void lcd_delete(struct kref *kref)
 69{
 70	struct usb_lcd *dev = to_lcd_dev(kref);
 71
 72	usb_put_dev(dev->udev);
 73	kfree(dev->bulk_in_buffer);
 74	kfree(dev);
 75}
 76
 77
 78static int lcd_open(struct inode *inode, struct file *file)
 79{
 80	struct usb_lcd *dev;
 81	struct usb_interface *interface;
 82	int subminor, r;
 83
 84	mutex_lock(&lcd_mutex);
 85	subminor = iminor(inode);
 86
 87	interface = usb_find_interface(&lcd_driver, subminor);
 88	if (!interface) {
 89		mutex_unlock(&lcd_mutex);
 90		printk(KERN_ERR "USBLCD: %s - error, can't find device for minor %d\n",
 91		       __func__, subminor);
 92		return -ENODEV;
 93	}
 94
 95	mutex_lock(&open_disc_mutex);
 96	dev = usb_get_intfdata(interface);
 97	if (!dev) {
 98		mutex_unlock(&open_disc_mutex);
 99		mutex_unlock(&lcd_mutex);
100		return -ENODEV;
101	}
102
103	/* increment our usage count for the device */
104	kref_get(&dev->kref);
105	mutex_unlock(&open_disc_mutex);
106
107	/* grab a power reference */
108	r = usb_autopm_get_interface(interface);
109	if (r < 0) {
110		kref_put(&dev->kref, lcd_delete);
111		mutex_unlock(&lcd_mutex);
112		return r;
113	}
114
115	/* save our object in the file's private structure */
116	file->private_data = dev;
117	mutex_unlock(&lcd_mutex);
118
119	return 0;
120}
121
122static int lcd_release(struct inode *inode, struct file *file)
123{
124	struct usb_lcd *dev;
125
126	dev = file->private_data;
127	if (dev == NULL)
128		return -ENODEV;
129
130	/* decrement the count on our device */
131	usb_autopm_put_interface(dev->interface);
132	kref_put(&dev->kref, lcd_delete);
133	return 0;
134}
135
136static ssize_t lcd_read(struct file *file, char __user * buffer,
137			size_t count, loff_t *ppos)
138{
139	struct usb_lcd *dev;
140	int retval = 0;
141	int bytes_read;
142
143	dev = file->private_data;
144
145	/* do a blocking bulk read to get data from the device */
146	retval = usb_bulk_msg(dev->udev,
147			      usb_rcvbulkpipe(dev->udev,
148					      dev->bulk_in_endpointAddr),
149			      dev->bulk_in_buffer,
150			      min(dev->bulk_in_size, count),
151			      &bytes_read, 10000);
152
153	/* if the read was successful, copy the data to userspace */
154	if (!retval) {
155		if (copy_to_user(buffer, dev->bulk_in_buffer, bytes_read))
156			retval = -EFAULT;
157		else
158			retval = bytes_read;
159	}
160
161	return retval;
162}
163
164static long lcd_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
165{
166	struct usb_lcd *dev;
167	u16 bcdDevice;
168	char buf[30];
169
170	dev = file->private_data;
171	if (dev == NULL)
172		return -ENODEV;
173
174	switch (cmd) {
175	case IOCTL_GET_HARD_VERSION:
176		mutex_lock(&lcd_mutex);
177		bcdDevice = le16_to_cpu((dev->udev)->descriptor.bcdDevice);
178		sprintf(buf, "%1d%1d.%1d%1d",
179			(bcdDevice & 0xF000)>>12,
180			(bcdDevice & 0xF00)>>8,
181			(bcdDevice & 0xF0)>>4,
182			(bcdDevice & 0xF));
183		mutex_unlock(&lcd_mutex);
184		if (copy_to_user((void __user *)arg, buf, strlen(buf)) != 0)
185			return -EFAULT;
186		break;
187	case IOCTL_GET_DRV_VERSION:
188		sprintf(buf, DRIVER_VERSION);
189		if (copy_to_user((void __user *)arg, buf, strlen(buf)) != 0)
190			return -EFAULT;
191		break;
192	default:
193		return -ENOTTY;
194		break;
195	}
196
197	return 0;
198}
199
200static void lcd_write_bulk_callback(struct urb *urb)
201{
202	struct usb_lcd *dev;
203	int status = urb->status;
204
205	dev = urb->context;
206
207	/* sync/async unlink faults aren't errors */
208	if (status &&
209	    !(status == -ENOENT ||
210	      status == -ECONNRESET ||
211	      status == -ESHUTDOWN)) {
212		dev_dbg(&dev->interface->dev,
213			"nonzero write bulk status received: %d\n", status);
214	}
215
216	/* free up our allocated buffer */
217	usb_free_coherent(urb->dev, urb->transfer_buffer_length,
218			  urb->transfer_buffer, urb->transfer_dma);
219	up(&dev->limit_sem);
220}
221
222static ssize_t lcd_write(struct file *file, const char __user * user_buffer,
223			 size_t count, loff_t *ppos)
224{
225	struct usb_lcd *dev;
226	int retval = 0, r;
227	struct urb *urb = NULL;
228	char *buf = NULL;
229
230	dev = file->private_data;
231
232	/* verify that we actually have some data to write */
233	if (count == 0)
234		goto exit;
235
236	r = down_interruptible(&dev->limit_sem);
237	if (r < 0)
238		return -EINTR;
239
240	/* create a urb, and a buffer for it, and copy the data to the urb */
241	urb = usb_alloc_urb(0, GFP_KERNEL);
242	if (!urb) {
243		retval = -ENOMEM;
244		goto err_no_buf;
245	}
246
247	buf = usb_alloc_coherent(dev->udev, count, GFP_KERNEL,
248				 &urb->transfer_dma);
249	if (!buf) {
250		retval = -ENOMEM;
251		goto error;
252	}
253
254	if (copy_from_user(buf, user_buffer, count)) {
255		retval = -EFAULT;
256		goto error;
257	}
258
259	/* initialize the urb properly */
260	usb_fill_bulk_urb(urb, dev->udev,
261			  usb_sndbulkpipe(dev->udev,
262			  dev->bulk_out_endpointAddr),
263			  buf, count, lcd_write_bulk_callback, dev);
264	urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
265
266	usb_anchor_urb(urb, &dev->submitted);
267
268	/* send the data out the bulk port */
269	retval = usb_submit_urb(urb, GFP_KERNEL);
270	if (retval) {
271		dev_err(&dev->udev->dev,
272			"%s - failed submitting write urb, error %d\n",
273			__func__, retval);
274		goto error_unanchor;
275	}
276
277	/* release our reference to this urb,
278	   the USB core will eventually free it entirely */
279	usb_free_urb(urb);
280
281exit:
282	return count;
283error_unanchor:
284	usb_unanchor_urb(urb);
285error:
286	usb_free_coherent(dev->udev, count, buf, urb->transfer_dma);
287	usb_free_urb(urb);
288err_no_buf:
289	up(&dev->limit_sem);
290	return retval;
291}
292
293static const struct file_operations lcd_fops = {
294	.owner =        THIS_MODULE,
295	.read =         lcd_read,
296	.write =        lcd_write,
297	.open =         lcd_open,
298	.unlocked_ioctl = lcd_ioctl,
299	.release =      lcd_release,
300	.llseek =	 noop_llseek,
301};
302
303/*
304 * usb class driver info in order to get a minor number from the usb core,
305 * and to have the device registered with the driver core
306 */
307static struct usb_class_driver lcd_class = {
308	.name =         "lcd%d",
309	.fops =         &lcd_fops,
310	.minor_base =   USBLCD_MINOR,
311};
312
313static int lcd_probe(struct usb_interface *interface,
314		     const struct usb_device_id *id)
315{
316	struct usb_lcd *dev = NULL;
317	struct usb_endpoint_descriptor *bulk_in, *bulk_out;
 
 
318	int i;
319	int retval;
320
321	/* allocate memory for our device state and initialize it */
322	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
323	if (!dev)
324		return -ENOMEM;
325
 
326	kref_init(&dev->kref);
327	sema_init(&dev->limit_sem, USB_LCD_CONCURRENT_WRITES);
328	init_usb_anchor(&dev->submitted);
329
330	dev->udev = usb_get_dev(interface_to_usbdev(interface));
331	dev->interface = interface;
332
333	if (le16_to_cpu(dev->udev->descriptor.idProduct) != 0x0001) {
334		dev_warn(&interface->dev, "USBLCD model not supported.\n");
335		retval = -ENODEV;
336		goto error;
337	}
338
339	/* set up the endpoint information */
340	/* use only the first bulk-in and bulk-out endpoints */
341	retval = usb_find_common_endpoints(interface->cur_altsetting,
342			&bulk_in, &bulk_out, NULL, NULL);
343	if (retval) {
344		dev_err(&interface->dev,
345			"Could not find both bulk-in and bulk-out endpoints\n");
346		goto error;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
347	}
348
349	dev->bulk_in_size = usb_endpoint_maxp(bulk_in);
350	dev->bulk_in_endpointAddr = bulk_in->bEndpointAddress;
351	dev->bulk_in_buffer = kmalloc(dev->bulk_in_size, GFP_KERNEL);
352	if (!dev->bulk_in_buffer) {
353		retval = -ENOMEM;
354		goto error;
355	}
356
357	dev->bulk_out_endpointAddr = bulk_out->bEndpointAddress;
358
359	/* save our data pointer in this interface device */
360	usb_set_intfdata(interface, dev);
361
362	/* we can register the device now, as it is ready */
363	retval = usb_register_dev(interface, &lcd_class);
364	if (retval) {
365		/* something prevented us from registering this driver */
366		dev_err(&interface->dev,
367			"Not able to get a minor for this device.\n");
368		usb_set_intfdata(interface, NULL);
369		goto error;
370	}
371
372	i = le16_to_cpu(dev->udev->descriptor.bcdDevice);
373
374	dev_info(&interface->dev, "USBLCD Version %1d%1d.%1d%1d found "
375		 "at address %d\n", (i & 0xF000)>>12, (i & 0xF00)>>8,
376		 (i & 0xF0)>>4, (i & 0xF), dev->udev->devnum);
377
378	/* let the user know what node this device is now attached to */
379	dev_info(&interface->dev, "USB LCD device now attached to USBLCD-%d\n",
380		 interface->minor);
381	return 0;
382
383error:
384	kref_put(&dev->kref, lcd_delete);
 
385	return retval;
386}
387
388static void lcd_draw_down(struct usb_lcd *dev)
389{
390	int time;
391
392	time = usb_wait_anchor_empty_timeout(&dev->submitted, 1000);
393	if (!time)
394		usb_kill_anchored_urbs(&dev->submitted);
395}
396
397static int lcd_suspend(struct usb_interface *intf, pm_message_t message)
398{
399	struct usb_lcd *dev = usb_get_intfdata(intf);
400
401	if (!dev)
402		return 0;
403	lcd_draw_down(dev);
404	return 0;
405}
406
407static int lcd_resume(struct usb_interface *intf)
408{
409	return 0;
410}
411
412static void lcd_disconnect(struct usb_interface *interface)
413{
414	struct usb_lcd *dev;
415	int minor = interface->minor;
416
417	mutex_lock(&open_disc_mutex);
418	dev = usb_get_intfdata(interface);
419	usb_set_intfdata(interface, NULL);
420	mutex_unlock(&open_disc_mutex);
421
422	/* give back our minor */
423	usb_deregister_dev(interface, &lcd_class);
424
425	/* decrement our usage count */
426	kref_put(&dev->kref, lcd_delete);
427
428	dev_info(&interface->dev, "USB LCD #%d now disconnected\n", minor);
429}
430
431static struct usb_driver lcd_driver = {
432	.name =		"usblcd",
433	.probe =	lcd_probe,
434	.disconnect =	lcd_disconnect,
435	.suspend =	lcd_suspend,
436	.resume =	lcd_resume,
437	.id_table =	id_table,
438	.supports_autosuspend = 1,
439};
440
441module_usb_driver(lcd_driver);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
442
443MODULE_AUTHOR("Georges Toth <g.toth@e-biz.lu>");
444MODULE_DESCRIPTION(DRIVER_VERSION);
445MODULE_LICENSE("GPL");