[linux-2.6-block.git] / drivers / usb / misc / usblcd.c

/*****************************************************************************
 *                          USBLCD Kernel Driver                             *
 *                            Version 1.05                                   *
 *             (C) 2005 Georges Toth <g.toth@e-biz.lu>                       *
 *                                                                           *
 *     This file is licensed under the GPL. See COPYING in the package.      *
 * Based on usb-skeleton.c 2.0 by Greg Kroah-Hartman (greg@kroah.com)        *
 *                                                                           *
 *                                                                           *
 * 28.02.05 Complete rewrite of the original usblcd.c driver,                *
 *          based on usb_skeleton.c.                                         *
 *          This new driver allows more than one USB-LCD to be connected     *
 *          and controlled, at once                                          *
 *****************************************************************************/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/errno.h>
#include <linux/mutex.h>
#include <linux/uaccess.h>
#include <linux/usb.h>

#define DRIVER_VERSION "USBLCD Driver Version 1.05"

#define USBLCD_MINOR		144

#define IOCTL_GET_HARD_VERSION	1
#define IOCTL_GET_DRV_VERSION	2


static DEFINE_MUTEX(lcd_mutex);
static const struct usb_device_id id_table[] = {
	{ .idVendor = 0x10D2, .match_flags = USB_DEVICE_ID_MATCH_VENDOR, },
	{ },
};
MODULE_DEVICE_TABLE(usb, id_table);

static DEFINE_MUTEX(open_disc_mutex);


struct usb_lcd {
	struct usb_device	*udev;			/* init: probe_lcd */
	struct usb_interface	*interface;		/* the interface for
							   this device */
	unsigned char		*bulk_in_buffer;	/* the buffer to receive
							   data */
	size_t			bulk_in_size;		/* the size of the
							   receive buffer */
	__u8			bulk_in_endpointAddr;	/* the address of the
							   bulk in endpoint */
	__u8			bulk_out_endpointAddr;	/* the address of the
							   bulk out endpoint */
	struct kref		kref;
	struct semaphore	limit_sem;		/* to stop writes at
							   full throttle from
							   using up all RAM */
	struct usb_anchor	submitted;		/* URBs to wait for
							   before suspend */
};
#define to_lcd_dev(d) container_of(d, struct usb_lcd, kref)

#define USB_LCD_CONCURRENT_WRITES	5

static struct usb_driver lcd_driver;


static void lcd_delete(struct kref *kref)
{
	struct usb_lcd *dev = to_lcd_dev(kref);

	usb_put_dev(dev->udev);
	kfree(dev->bulk_in_buffer);
	kfree(dev);
}


static int lcd_open(struct inode *inode, struct file *file)
{
	struct usb_lcd *dev;
	struct usb_interface *interface;
	int subminor, r;

	mutex_lock(&lcd_mutex);
	subminor = iminor(inode);

	interface = usb_find_interface(&lcd_driver, subminor);
	if (!interface) {
		mutex_unlock(&lcd_mutex);
		err("USBLCD: %s - error, can't find device for minor %d",
		     __func__, subminor);
		return -ENODEV;
	}

	mutex_lock(&open_disc_mutex);
	dev = usb_get_intfdata(interface);
	if (!dev) {
		mutex_unlock(&open_disc_mutex);
		mutex_unlock(&lcd_mutex);
		return -ENODEV;
	}

	/* increment our usage count for the device */
	kref_get(&dev->kref);
	mutex_unlock(&open_disc_mutex);

	/* grab a power reference */
	r = usb_autopm_get_interface(interface);
	if (r < 0) {
		kref_put(&dev->kref, lcd_delete);
		mutex_unlock(&lcd_mutex);
		return r;
	}

	/* save our object in the file's private structure */
	file->private_data = dev;
	mutex_unlock(&lcd_mutex);

	return 0;
}

static int lcd_release(struct inode *inode, struct file *file)
{
	struct usb_lcd *dev;

	dev = file->private_data;
	if (dev == NULL)
		return -ENODEV;

	/* decrement the count on our device */
	usb_autopm_put_interface(dev->interface);
	kref_put(&dev->kref, lcd_delete);
	return 0;
}

static ssize_t lcd_read(struct file *file, char __user * buffer,
			size_t count, loff_t *ppos)
{
	struct usb_lcd *dev;
	int retval = 0;
	int bytes_read;

	dev = file->private_data;

	/* do a blocking bulk read to get data from the device */
	retval = usb_bulk_msg(dev->udev,
			      usb_rcvbulkpipe(dev->udev,
					      dev->bulk_in_endpointAddr),
			      dev->bulk_in_buffer,
			      min(dev->bulk_in_size, count),
			      &bytes_read, 10000);

	/* if the read was successful, copy the data to userspace */
	if (!retval) {
		if (copy_to_user(buffer, dev->bulk_in_buffer, bytes_read))
			retval = -EFAULT;
		else
			retval = bytes_read;
	}

	return retval;
}

static long lcd_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
	struct usb_lcd *dev;
	u16 bcdDevice;
	char buf[30];

	dev = file->private_data;
	if (dev == NULL)
		return -ENODEV;

	switch (cmd) {
	case IOCTL_GET_HARD_VERSION:
		mutex_lock(&lcd_mutex);
		bcdDevice = le16_to_cpu((dev->udev)->descriptor.bcdDevice);
		sprintf(buf, "%1d%1d.%1d%1d",
			(bcdDevice & 0xF000)>>12,
			(bcdDevice & 0xF00)>>8,
			(bcdDevice & 0xF0)>>4,
			(bcdDevice & 0xF));
		mutex_unlock(&lcd_mutex);
		if (copy_to_user((void __user *)arg, buf, strlen(buf)) != 0)
			return -EFAULT;
		break;
	case IOCTL_GET_DRV_VERSION:
		sprintf(buf, DRIVER_VERSION);
		if (copy_to_user((void __user *)arg, buf, strlen(buf)) != 0)
			return -EFAULT;
		break;
	default:
		return -ENOTTY;
		break;
	}

	return 0;
}

static void lcd_write_bulk_callback(struct urb *urb)
{
	struct usb_lcd *dev;
	int status = urb->status;

	dev = urb->context;

	/* sync/async unlink faults aren't errors */
	if (status &&
	    !(status == -ENOENT ||
	      status == -ECONNRESET ||
	      status == -ESHUTDOWN)) {
		dbg("USBLCD: %s - nonzero write bulk status received: %d",
		    __func__, status);
	}

	/* free up our allocated buffer */
	usb_free_coherent(urb->dev, urb->transfer_buffer_length,
			  urb->transfer_buffer, urb->transfer_dma);
	up(&dev->limit_sem);
}

static ssize_t lcd_write(struct file *file, const char __user * user_buffer,
			 size_t count, loff_t *ppos)
{
	struct usb_lcd *dev;
	int retval = 0, r;
	struct urb *urb = NULL;
	char *buf = NULL;

	dev = file->private_data;

	/* verify that we actually have some data to write */
	if (count == 0)
		goto exit;

	r = down_interruptible(&dev->limit_sem);
	if (r < 0)
		return -EINTR;

	/* create a urb, and a buffer for it, and copy the data to the urb */
	urb = usb_alloc_urb(0, GFP_KERNEL);
	if (!urb) {
		retval = -ENOMEM;
		goto err_no_buf;
	}

	buf = usb_alloc_coherent(dev->udev, count, GFP_KERNEL,
				 &urb->transfer_dma);
	if (!buf) {
		retval = -ENOMEM;
		goto error;
	}

	if (copy_from_user(buf, user_buffer, count)) {
		retval = -EFAULT;
		goto error;
	}

	/* initialize the urb properly */
	usb_fill_bulk_urb(urb, dev->udev,
			  usb_sndbulkpipe(dev->udev,
			  dev->bulk_out_endpointAddr),
			  buf, count, lcd_write_bulk_callback, dev);
	urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;

	usb_anchor_urb(urb, &dev->submitted);

	/* send the data out the bulk port */
	retval = usb_submit_urb(urb, GFP_KERNEL);
	if (retval) {
		err("USBLCD: %s - failed submitting write urb, error %d",
		    __func__, retval);
		goto error_unanchor;
	}

	/* release our reference to this urb,
	   the USB core will eventually free it entirely */
	usb_free_urb(urb);

exit:
	return count;
error_unanchor:
	usb_unanchor_urb(urb);
error:
	usb_free_coherent(dev->udev, count, buf, urb->transfer_dma);
	usb_free_urb(urb);
err_no_buf:
	up(&dev->limit_sem);
	return retval;
}

static const struct file_operations lcd_fops = {
	.owner =        THIS_MODULE,
	.read =         lcd_read,
	.write =        lcd_write,
	.open =         lcd_open,
	.unlocked_ioctl = lcd_ioctl,
	.release =      lcd_release,
	.llseek =	 noop_llseek,
};

/*
 * usb class driver info in order to get a minor number from the usb core,
 * and to have the device registered with the driver core
 */
static struct usb_class_driver lcd_class = {
	.name =         "lcd%d",
	.fops =         &lcd_fops,
	.minor_base =   USBLCD_MINOR,
};

static int lcd_probe(struct usb_interface *interface,
		     const struct usb_device_id *id)
{
	struct usb_lcd *dev = NULL;
	struct usb_host_interface *iface_desc;
	struct usb_endpoint_descriptor *endpoint;
	size_t buffer_size;
	int i;
	int retval = -ENOMEM;

	/* allocate memory for our device state and initialize it */
	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
	if (dev == NULL) {
		err("Out of memory");
		goto error;
	}
	kref_init(&dev->kref);
	sema_init(&dev->limit_sem, USB_LCD_CONCURRENT_WRITES);
	init_usb_anchor(&dev->submitted);

	dev->udev = usb_get_dev(interface_to_usbdev(interface));
	dev->interface = interface;

	if (le16_to_cpu(dev->udev->descriptor.idProduct) != 0x0001) {
		dev_warn(&interface->dev, "USBLCD model not supported.\n");
		retval = -ENODEV;
		goto error;
	}

	/* set up the endpoint information */
	/* use only the first bulk-in and bulk-out endpoints */
	iface_desc = interface->cur_altsetting;
	for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
		endpoint = &iface_desc->endpoint[i].desc;

		if (!dev->bulk_in_endpointAddr &&
		    usb_endpoint_is_bulk_in(endpoint)) {
			/* we found a bulk in endpoint */
			buffer_size = usb_endpoint_maxp(endpoint);
			dev->bulk_in_size = buffer_size;
			dev->bulk_in_endpointAddr = endpoint->bEndpointAddress;
			dev->bulk_in_buffer = kmalloc(buffer_size, GFP_KERNEL);
			if (!dev->bulk_in_buffer) {
				err("Could not allocate bulk_in_buffer");
				goto error;
			}
		}

		if (!dev->bulk_out_endpointAddr &&
		    usb_endpoint_is_bulk_out(endpoint)) {
			/* we found a bulk out endpoint */
			dev->bulk_out_endpointAddr = endpoint->bEndpointAddress;
		}
	}
	if (!(dev->bulk_in_endpointAddr && dev->bulk_out_endpointAddr)) {
		err("Could not find both bulk-in and bulk-out endpoints");
		goto error;
	}

	/* save our data pointer in this interface device */
	usb_set_intfdata(interface, dev);

	/* we can register the device now, as it is ready */
	retval = usb_register_dev(interface, &lcd_class);
	if (retval) {
		/* something prevented us from registering this driver */
		err("Not able to get a minor for this device.");
		usb_set_intfdata(interface, NULL);
		goto error;
	}

	i = le16_to_cpu(dev->udev->descriptor.bcdDevice);

	dev_info(&interface->dev, "USBLCD Version %1d%1d.%1d%1d found "
		 "at address %d\n", (i & 0xF000)>>12, (i & 0xF00)>>8,
		 (i & 0xF0)>>4, (i & 0xF), dev->udev->devnum);

	/* let the user know what node this device is now attached to */
	dev_info(&interface->dev, "USB LCD device now attached to USBLCD-%d\n",
		 interface->minor);
	return 0;

error:
	if (dev)
		kref_put(&dev->kref, lcd_delete);
	return retval;
}

static void lcd_draw_down(struct usb_lcd *dev)
{
	int time;

	time = usb_wait_anchor_empty_timeout(&dev->submitted, 1000);
	if (!time)
		usb_kill_anchored_urbs(&dev->submitted);
}

static int lcd_suspend(struct usb_interface *intf, pm_message_t message)
{
	struct usb_lcd *dev = usb_get_intfdata(intf);

	if (!dev)
		return 0;
	lcd_draw_down(dev);
	return 0;
}

static int lcd_resume(struct usb_interface *intf)
{
	return 0;
}

static void lcd_disconnect(struct usb_interface *interface)
{
	struct usb_lcd *dev;
	int minor = interface->minor;

	mutex_lock(&open_disc_mutex);
	dev = usb_get_intfdata(interface);
	usb_set_intfdata(interface, NULL);
	mutex_unlock(&open_disc_mutex);

	/* give back our minor */
	usb_deregister_dev(interface, &lcd_class);

	/* decrement our usage count */
	kref_put(&dev->kref, lcd_delete);

	dev_info(&interface->dev, "USB LCD #%d now disconnected\n", minor);
}

static struct usb_driver lcd_driver = {
	.name =		"usblcd",
	.probe =	lcd_probe,
	.disconnect =	lcd_disconnect,
	.suspend =	lcd_suspend,
	.resume =	lcd_resume,
	.id_table =	id_table,
	.supports_autosuspend = 1,
};

static int __init usb_lcd_init(void)
{
	int result;

	result = usb_register(&lcd_driver);
	if (result)
		err("usb_register failed. Error number %d", result);

	return result;
}


static void __exit usb_lcd_exit(void)
{
	usb_deregister(&lcd_driver);
}

module_init(usb_lcd_init);
module_exit(usb_lcd_exit);

MODULE_AUTHOR("Georges Toth <g.toth@e-biz.lu>");
MODULE_DESCRIPTION(DRIVER_VERSION);
MODULE_LICENSE("GPL");
Commit	Line	Data
1da177e4 LT	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>
d5d1ceac	20	#include <linux/mutex.h>
507a3ea7	21	#include <linux/uaccess.h>
1da177e4 LT	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
925ce689	32	static DEFINE_MUTEX(lcd_mutex);
33b9e162	33	static const struct usb_device_id id_table[] = {
1da177e4 LT	34	{ .idVendor = 0x10D2, .match_flags = USB_DEVICE_ID_MATCH_VENDOR, },
	35	{ },
	36	};
507a3ea7	37	MODULE_DEVICE_TABLE(usb, id_table);
1da177e4	38
d5d1ceac ON	39	static DEFINE_MUTEX(open_disc_mutex);
d5d1ceac ON	40
1da177e4 LT	41
1da177e4 LT	42	struct usb_lcd {
507a3ea7 ZP	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 */
5afeb104	54	struct kref kref;
507a3ea7 ZP	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 */
1da177e4 LT	60	};
	61	#define to_lcd_dev(d) container_of(d, struct usb_lcd, kref)
	62
5afeb104 ON	63	#define USB_LCD_CONCURRENT_WRITES 5
5afeb104 ON	64
1da177e4 LT	65	static struct usb_driver lcd_driver;
	66
	67
	68	static void lcd_delete(struct kref *kref)
	69	{
	70	struct usb_lcd *dev = to_lcd_dev(kref);
	71
	72	usb_put_dev(dev->udev);
507a3ea7 ZP	73	kfree(dev->bulk_in_buffer);
507a3ea7 ZP	74	kfree(dev);
1da177e4 LT	75	}
	76
	77
	78	static int lcd_open(struct inode inode, struct file file)
	79	{
	80	struct usb_lcd *dev;
	81	struct usb_interface *interface;
7bbe990c	82	int subminor, r;
1da177e4	83
925ce689	84	mutex_lock(&lcd_mutex);
1da177e4 LT	85	subminor = iminor(inode);
	86
	87	interface = usb_find_interface(&lcd_driver, subminor);
	88	if (!interface) {
925ce689	89	mutex_unlock(&lcd_mutex);
507a3ea7	90	err("USBLCD: %s - error, can't find device for minor %d",
441b62c1	91	__func__, subminor);
d4ead16f	92	return -ENODEV;
1da177e4 LT	93	}
1da177e4 LT	94
d5d1ceac	95	mutex_lock(&open_disc_mutex);
1da177e4	96	dev = usb_get_intfdata(interface);
d5d1ceac ON	97	if (!dev) {
d5d1ceac ON	98	mutex_unlock(&open_disc_mutex);
925ce689	99	mutex_unlock(&lcd_mutex);
d4ead16f	100	return -ENODEV;
d5d1ceac	101	}
1da177e4 LT	102
	103	/* increment our usage count for the device */
	104	kref_get(&dev->kref);
d5d1ceac	105	mutex_unlock(&open_disc_mutex);
1da177e4	106
7bbe990c ON	107	/* grab a power reference */
	108	r = usb_autopm_get_interface(interface);
	109	if (r < 0) {
	110	kref_put(&dev->kref, lcd_delete);
925ce689	111	mutex_unlock(&lcd_mutex);
7bbe990c ON	112	return r;
	113	}
	114
1da177e4 LT	115	/* save our object in the file's private structure */
1da177e4 LT	116	file->private_data = dev;
925ce689	117	mutex_unlock(&lcd_mutex);
1da177e4	118
d4ead16f	119	return 0;
1da177e4 LT	120	}
	121
	122	static int lcd_release(struct inode inode, struct file file)
	123	{
	124	struct usb_lcd *dev;
	125
5bd6e8b3	126	dev = file->private_data;
1da177e4 LT	127	if (dev == NULL)
	128	return -ENODEV;
	129
	130	/* decrement the count on our device */
7bbe990c	131	usb_autopm_put_interface(dev->interface);
1da177e4 LT	132	kref_put(&dev->kref, lcd_delete);
	133	return 0;
	134	}
	135
507a3ea7 ZP	136	static ssize_t lcd_read(struct file file, char __user buffer,
507a3ea7 ZP	137	size_t count, loff_t *ppos)
1da177e4 LT	138	{
	139	struct usb_lcd *dev;
	140	int retval = 0;
	141	int bytes_read;
	142
5bd6e8b3	143	dev = file->private_data;
1da177e4 LT	144
1da177e4 LT	145	/* do a blocking bulk read to get data from the device */
507a3ea7 ZP	146	retval = usb_bulk_msg(dev->udev,
	147	usb_rcvbulkpipe(dev->udev,
	148	dev->bulk_in_endpointAddr),
1da177e4 LT	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
5cb4aeca	164	static long lcd_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1da177e4 LT	165	{
	166	struct usb_lcd *dev;
	167	u16 bcdDevice;
	168	char buf[30];
	169
5bd6e8b3	170	dev = file->private_data;
1da177e4 LT	171	if (dev == NULL)
1da177e4 LT	172	return -ENODEV;
507a3ea7	173
1da177e4 LT	174	switch (cmd) {
1da177e4 LT	175	case IOCTL_GET_HARD_VERSION:
925ce689	176	mutex_lock(&lcd_mutex);
1da177e4	177	bcdDevice = le16_to_cpu((dev->udev)->descriptor.bcdDevice);
507a3ea7	178	sprintf(buf, "%1d%1d.%1d%1d",
1da177e4 LT	179	(bcdDevice & 0xF000)>>12,
	180	(bcdDevice & 0xF00)>>8,
	181	(bcdDevice & 0xF0)>>4,
	182	(bcdDevice & 0xF));
925ce689	183	mutex_unlock(&lcd_mutex);
507a3ea7	184	if (copy_to_user((void __user *)arg, buf, strlen(buf)) != 0)
1da177e4 LT	185	return -EFAULT;
	186	break;
	187	case IOCTL_GET_DRV_VERSION:
507a3ea7 ZP	188	sprintf(buf, DRIVER_VERSION);
507a3ea7 ZP	189	if (copy_to_user((void __user *)arg, buf, strlen(buf)) != 0)
1da177e4 LT	190	return -EFAULT;
	191	break;
	192	default:
	193	return -ENOTTY;
	194	break;
	195	}
	196
	197	return 0;
	198	}
	199
7d12e780	200	static void lcd_write_bulk_callback(struct urb *urb)
1da177e4 LT	201	{
1da177e4 LT	202	struct usb_lcd *dev;
0723af13	203	int status = urb->status;
1da177e4	204
cdc97792	205	dev = urb->context;
1da177e4 LT	206
1da177e4 LT	207	/* sync/async unlink faults aren't errors */
0723af13 GKH	208	if (status &&
	209	!(status == -ENOENT \|\|
	210	status == -ECONNRESET \|\|
507a3ea7	211	status == -ESHUTDOWN)) {
1da177e4	212	dbg("USBLCD: %s - nonzero write bulk status received: %d",
441b62c1	213	__func__, status);
1da177e4 LT	214	}
	215
	216	/* free up our allocated buffer */
997ea58e DM	217	usb_free_coherent(urb->dev, urb->transfer_buffer_length,
997ea58e DM	218	urb->transfer_buffer, urb->transfer_dma);
5afeb104	219	up(&dev->limit_sem);
1da177e4 LT	220	}
1da177e4 LT	221
507a3ea7 ZP	222	static ssize_t lcd_write(struct file file, const char __user user_buffer,
507a3ea7 ZP	223	size_t count, loff_t *ppos)
1da177e4 LT	224	{
1da177e4 LT	225	struct usb_lcd *dev;
507a3ea7	226	int retval = 0, r;
1da177e4 LT	227	struct urb *urb = NULL;
1da177e4 LT	228	char *buf = NULL;
507a3ea7	229
5bd6e8b3	230	dev = file->private_data;
507a3ea7	231
1da177e4 LT	232	/* verify that we actually have some data to write */
	233	if (count == 0)
	234	goto exit;
	235
5afeb104 ON	236	r = down_interruptible(&dev->limit_sem);
	237	if (r < 0)
	238	return -EINTR;
	239
1da177e4 LT	240	/* create a urb, and a buffer for it, and copy the data to the urb */
1da177e4 LT	241	urb = usb_alloc_urb(0, GFP_KERNEL);
5afeb104 ON	242	if (!urb) {
	243	retval = -ENOMEM;
	244	goto err_no_buf;
	245	}
507a3ea7 ZP	246
	247	buf = usb_alloc_coherent(dev->udev, count, GFP_KERNEL,
	248	&urb->transfer_dma);
1da177e4 LT	249	if (!buf) {
	250	retval = -ENOMEM;
	251	goto error;
	252	}
507a3ea7	253
1da177e4 LT	254	if (copy_from_user(buf, user_buffer, count)) {
	255	retval = -EFAULT;
	256	goto error;
	257	}
507a3ea7	258
1da177e4 LT	259	/* initialize the urb properly */
1da177e4 LT	260	usb_fill_bulk_urb(urb, dev->udev,
507a3ea7 ZP	261	usb_sndbulkpipe(dev->udev,
507a3ea7 ZP	262	dev->bulk_out_endpointAddr),
1da177e4 LT	263	buf, count, lcd_write_bulk_callback, dev);
1da177e4 LT	264	urb->transfer_flags \|= URB_NO_TRANSFER_DMA_MAP;
7bbe990c ON	265
7bbe990c ON	266	usb_anchor_urb(urb, &dev->submitted);
507a3ea7	267
1da177e4 LT	268	/* send the data out the bulk port */
	269	retval = usb_submit_urb(urb, GFP_KERNEL);
	270	if (retval) {
507a3ea7 ZP	271	err("USBLCD: %s - failed submitting write urb, error %d",
507a3ea7 ZP	272	__func__, retval);
7bbe990c	273	goto error_unanchor;
1da177e4	274	}
507a3ea7 ZP	275
	276	/* release our reference to this urb,
	277	the USB core will eventually free it entirely */
1da177e4 LT	278	usb_free_urb(urb);
	279
	280	exit:
	281	return count;
7bbe990c ON	282	error_unanchor:
7bbe990c ON	283	usb_unanchor_urb(urb);
1da177e4	284	error:
997ea58e	285	usb_free_coherent(dev->udev, count, buf, urb->transfer_dma);
1da177e4	286	usb_free_urb(urb);
5afeb104 ON	287	err_no_buf:
5afeb104 ON	288	up(&dev->limit_sem);
1da177e4 LT	289	return retval;
	290	}
	291
066202dd	292	static const struct file_operations lcd_fops = {
507a3ea7 ZP	293	.owner = THIS_MODULE,
	294	.read = lcd_read,
	295	.write = lcd_write,
	296	.open = lcd_open,
5cb4aeca	297	.unlocked_ioctl = lcd_ioctl,
507a3ea7 ZP	298	.release = lcd_release,
507a3ea7 ZP	299	.llseek = noop_llseek,
1da177e4 LT	300	};
	301
	302	/*
d6e5bcf4 GKH	303	* usb class driver info in order to get a minor number from the usb core,
	304	* and to have the device registered with the driver core
	305	*/
1da177e4	306	static struct usb_class_driver lcd_class = {
507a3ea7 ZP	307	.name = "lcd%d",
	308	.fops = &lcd_fops,
	309	.minor_base = USBLCD_MINOR,
1da177e4 LT	310	};
1da177e4 LT	311
507a3ea7 ZP	312	static int lcd_probe(struct usb_interface *interface,
507a3ea7 ZP	313	const struct usb_device_id *id)
1da177e4 LT	314	{
	315	struct usb_lcd *dev = NULL;
	316	struct usb_host_interface *iface_desc;
	317	struct usb_endpoint_descriptor *endpoint;
	318	size_t buffer_size;
	319	int i;
	320	int retval = -ENOMEM;
	321
	322	/* allocate memory for our device state and initialize it */
80b6ca48	323	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1da177e4 LT	324	if (dev == NULL) {
	325	err("Out of memory");
	326	goto error;
	327	}
1da177e4	328	kref_init(&dev->kref);
5afeb104	329	sema_init(&dev->limit_sem, USB_LCD_CONCURRENT_WRITES);
7bbe990c	330	init_usb_anchor(&dev->submitted);
1da177e4 LT	331
	332	dev->udev = usb_get_dev(interface_to_usbdev(interface));
	333	dev->interface = interface;
	334
	335	if (le16_to_cpu(dev->udev->descriptor.idProduct) != 0x0001) {
3b6004f3	336	dev_warn(&interface->dev, "USBLCD model not supported.\n");
696a4ace JS	337	retval = -ENODEV;
696a4ace JS	338	goto error;
1da177e4	339	}
507a3ea7	340
1da177e4 LT	341	/* set up the endpoint information */
	342	/* use only the first bulk-in and bulk-out endpoints */
	343	iface_desc = interface->cur_altsetting;
	344	for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
	345	endpoint = &iface_desc->endpoint[i].desc;
	346
	347	if (!dev->bulk_in_endpointAddr &&
b0b660b8	348	usb_endpoint_is_bulk_in(endpoint)) {
1da177e4	349	/* we found a bulk in endpoint */
29cc8897	350	buffer_size = usb_endpoint_maxp(endpoint);
1da177e4 LT	351	dev->bulk_in_size = buffer_size;
	352	dev->bulk_in_endpointAddr = endpoint->bEndpointAddress;
	353	dev->bulk_in_buffer = kmalloc(buffer_size, GFP_KERNEL);
	354	if (!dev->bulk_in_buffer) {
	355	err("Could not allocate bulk_in_buffer");
	356	goto error;
	357	}
	358	}
	359
	360	if (!dev->bulk_out_endpointAddr &&
b0b660b8	361	usb_endpoint_is_bulk_out(endpoint)) {
1da177e4 LT	362	/* we found a bulk out endpoint */
	363	dev->bulk_out_endpointAddr = endpoint->bEndpointAddress;
	364	}
	365	}
	366	if (!(dev->bulk_in_endpointAddr && dev->bulk_out_endpointAddr)) {
	367	err("Could not find both bulk-in and bulk-out endpoints");
	368	goto error;
	369	}
	370
	371	/* save our data pointer in this interface device */
	372	usb_set_intfdata(interface, dev);
	373
	374	/* we can register the device now, as it is ready */
	375	retval = usb_register_dev(interface, &lcd_class);
	376	if (retval) {
	377	/* something prevented us from registering this driver */
	378	err("Not able to get a minor for this device.");
	379	usb_set_intfdata(interface, NULL);
	380	goto error;
	381	}
	382
	383	i = le16_to_cpu(dev->udev->descriptor.bcdDevice);
	384
1b29a375 GKH	385	dev_info(&interface->dev, "USBLCD Version %1d%1d.%1d%1d found "
1b29a375 GKH	386	"at address %d\n", (i & 0xF000)>>12, (i & 0xF00)>>8,
507a3ea7	387	(i & 0xF0)>>4, (i & 0xF), dev->udev->devnum);
1da177e4 LT	388
1da177e4 LT	389	/* let the user know what node this device is now attached to */
1b29a375 GKH	390	dev_info(&interface->dev, "USB LCD device now attached to USBLCD-%d\n",
1b29a375 GKH	391	interface->minor);
1da177e4 LT	392	return 0;
	393
	394	error:
	395	if (dev)
	396	kref_put(&dev->kref, lcd_delete);
	397	return retval;
	398	}
	399
7bbe990c ON	400	static void lcd_draw_down(struct usb_lcd *dev)
	401	{
	402	int time;
	403
	404	time = usb_wait_anchor_empty_timeout(&dev->submitted, 1000);
	405	if (!time)
	406	usb_kill_anchored_urbs(&dev->submitted);
	407	}
	408
	409	static int lcd_suspend(struct usb_interface *intf, pm_message_t message)
	410	{
	411	struct usb_lcd *dev = usb_get_intfdata(intf);
	412
	413	if (!dev)
	414	return 0;
	415	lcd_draw_down(dev);
	416	return 0;
	417	}
	418
507a3ea7	419	static int lcd_resume(struct usb_interface *intf)
7bbe990c ON	420	{
	421	return 0;
	422	}
	423
1da177e4 LT	424	static void lcd_disconnect(struct usb_interface *interface)
	425	{
	426	struct usb_lcd *dev;
507a3ea7	427	int minor = interface->minor;
1da177e4	428
d5d1ceac	429	mutex_lock(&open_disc_mutex);
507a3ea7 ZP	430	dev = usb_get_intfdata(interface);
507a3ea7 ZP	431	usb_set_intfdata(interface, NULL);
d5d1ceac	432	mutex_unlock(&open_disc_mutex);
1da177e4	433
507a3ea7 ZP	434	/* give back our minor */
	435	usb_deregister_dev(interface, &lcd_class);
	436
1da177e4 LT	437	/* decrement our usage count */
	438	kref_put(&dev->kref, lcd_delete);
	439
1b29a375	440	dev_info(&interface->dev, "USB LCD #%d now disconnected\n", minor);
1da177e4 LT	441	}
	442
	443	static struct usb_driver lcd_driver = {
1da177e4 LT	444	.name = "usblcd",
	445	.probe = lcd_probe,
	446	.disconnect = lcd_disconnect,
7bbe990c ON	447	.suspend = lcd_suspend,
7bbe990c ON	448	.resume = lcd_resume,
1da177e4	449	.id_table = id_table,
7bbe990c	450	.supports_autosuspend = 1,
1da177e4 LT	451	};
	452
	453	static int __init usb_lcd_init(void)
	454	{
	455	int result;
507a3ea7	456
1da177e4 LT	457	result = usb_register(&lcd_driver);
	458	if (result)
	459	err("usb_register failed. Error number %d", result);
	460
	461	return result;
	462	}
	463
	464
	465	static void __exit usb_lcd_exit(void)
	466	{
	467	usb_deregister(&lcd_driver);
	468	}
	469
	470	module_init(usb_lcd_init);
	471	module_exit(usb_lcd_exit);
	472
	473	MODULE_AUTHOR("Georges Toth <g.toth@e-biz.lu>");
	474	MODULE_DESCRIPTION(DRIVER_VERSION);
	475	MODULE_LICENSE("GPL");