[net-next-2.6.git] / drivers / usb / usb-skeleton.c

/*
 * USB Skeleton driver - 2.0
 *
 * Copyright (C) 2001-2004 Greg Kroah-Hartman (greg@kroah.com)
 *
 *	This program is free software; you can redistribute it and/or
 *	modify it under the terms of the GNU General Public License as
 *	published by the Free Software Foundation, version 2.
 *
 * This driver is based on the 2.6.3 version of drivers/usb/usb-skeleton.c 
 * but has been rewritten to be easy to read and use, as no locks are now
 * needed anymore.
 *
 */

#include <linux/config.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/kref.h>
#include <asm/uaccess.h>
#include <linux/usb.h>


/* Define these values to match your devices */
#define USB_SKEL_VENDOR_ID	0xfff0
#define USB_SKEL_PRODUCT_ID	0xfff0

/* table of devices that work with this driver */
static struct usb_device_id skel_table [] = {
	{ USB_DEVICE(USB_SKEL_VENDOR_ID, USB_SKEL_PRODUCT_ID) },
	{ }					/* Terminating entry */
};
MODULE_DEVICE_TABLE (usb, skel_table);


/* Get a minor range for your devices from the usb maintainer */
#define USB_SKEL_MINOR_BASE	192

/* Structure to hold all of our device specific stuff */
struct usb_skel {
	struct usb_device *	udev;			/* the usb device for this device */
	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;
};
#define to_skel_dev(d) container_of(d, struct usb_skel, kref)

static struct usb_driver skel_driver;

static void skel_delete(struct kref *kref)
{	
	struct usb_skel *dev = to_skel_dev(kref);

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

static int skel_open(struct inode *inode, struct file *file)
{
	struct usb_skel *dev;
	struct usb_interface *interface;
	int subminor;
	int retval = 0;

	subminor = iminor(inode);

	interface = usb_find_interface(&skel_driver, subminor);
	if (!interface) {
		err ("%s - error, can't find device for minor %d",
		     __FUNCTION__, subminor);
		retval = -ENODEV;
		goto exit;
	}

	dev = usb_get_intfdata(interface);
	if (!dev) {
		retval = -ENODEV;
		goto exit;
	}

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

	/* save our object in the file's private structure */
	file->private_data = dev;

exit:
	return retval;
}

static int skel_release(struct inode *inode, struct file *file)
{
	struct usb_skel *dev;

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

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

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

	dev = (struct usb_skel *)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 void skel_write_bulk_callback(struct urb *urb, struct pt_regs *regs)
{
	struct usb_skel *dev;

	dev = (struct usb_skel *)urb->context;

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

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

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

	dev = (struct usb_skel *)file->private_data;

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

	/* 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 error;
	}

	buf = usb_buffer_alloc(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, skel_write_bulk_callback, dev);
	urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;

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

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

exit:
	return count;

error:
	usb_buffer_free(dev->udev, count, buf, urb->transfer_dma);
	usb_free_urb(urb);
	return retval;
}

static struct file_operations skel_fops = {
	.owner =	THIS_MODULE,
	.read =		skel_read,
	.write =	skel_write,
	.open =		skel_open,
	.release =	skel_release,
};

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

static int skel_probe(struct usb_interface *interface, const struct usb_device_id *id)
{
	struct usb_skel *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 = kmalloc(sizeof(*dev), GFP_KERNEL);
	if (dev == NULL) {
		err("Out of memory");
		goto error;
	}
	memset(dev, 0x00, sizeof(*dev));
	kref_init(&dev->kref);

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

	/* 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 &&
		    ((endpoint->bEndpointAddress & USB_ENDPOINT_DIR_MASK)
					== USB_DIR_IN) &&
		    ((endpoint->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK)
					== USB_ENDPOINT_XFER_BULK)) {
			/* we found a bulk in endpoint */
			buffer_size = le16_to_cpu(endpoint->wMaxPacketSize);
			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 &&
		    ((endpoint->bEndpointAddress & USB_ENDPOINT_DIR_MASK)
					== USB_DIR_OUT) &&
		    ((endpoint->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK)
					== USB_ENDPOINT_XFER_BULK)) {
			/* 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, &skel_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;
	}

	/* let the user know what node this device is now attached to */
	info("USB Skeleton device now attached to USBSkel-%d", interface->minor);
	return 0;

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

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

	/* prevent skel_open() from racing skel_disconnect() */
	lock_kernel();

	dev = usb_get_intfdata(interface);
	usb_set_intfdata(interface, NULL);

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

	unlock_kernel();

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

	info("USB Skeleton #%d now disconnected", minor);
}

static struct usb_driver skel_driver = {
	.name =		"skeleton",
	.probe =	skel_probe,
	.disconnect =	skel_disconnect,
	.id_table =	skel_table,
};

static int __init usb_skel_init(void)
{
	int result;

	/* register this driver with the USB subsystem */
	result = usb_register(&skel_driver);
	if (result)
		err("usb_register failed. Error number %d", result);

	return result;
}

static void __exit usb_skel_exit(void)
{
	/* deregister this driver with the USB subsystem */
	usb_deregister(&skel_driver);
}

module_init (usb_skel_init);
module_exit (usb_skel_exit);

MODULE_LICENSE("GPL");
Commit	Line	Data
1da177e4 LT	1	/*
	2	* USB Skeleton driver - 2.0
	3	*
	4	* Copyright (C) 2001-2004 Greg Kroah-Hartman (greg@kroah.com)
	5	*
	6	* This program is free software; you can redistribute it and/or
	7	* modify it under the terms of the GNU General Public License as
	8	* published by the Free Software Foundation, version 2.
	9	*
	10	* This driver is based on the 2.6.3 version of drivers/usb/usb-skeleton.c
	11	* but has been rewritten to be easy to read and use, as no locks are now
	12	* needed anymore.
	13	*
	14	*/
	15
	16	#include <linux/config.h>
	17	#include <linux/kernel.h>
	18	#include <linux/errno.h>
	19	#include <linux/init.h>
	20	#include <linux/slab.h>
	21	#include <linux/module.h>
	22	#include <linux/kref.h>
	23	#include <asm/uaccess.h>
	24	#include <linux/usb.h>
	25
	26
	27	/* Define these values to match your devices */
	28	#define USB_SKEL_VENDOR_ID 0xfff0
	29	#define USB_SKEL_PRODUCT_ID 0xfff0
	30
	31	/* table of devices that work with this driver */
	32	static struct usb_device_id skel_table [] = {
	33	{ USB_DEVICE(USB_SKEL_VENDOR_ID, USB_SKEL_PRODUCT_ID) },
	34	{ } /* Terminating entry */
	35	};
	36	MODULE_DEVICE_TABLE (usb, skel_table);
	37
	38
	39	/* Get a minor range for your devices from the usb maintainer */
	40	#define USB_SKEL_MINOR_BASE 192
	41
	42	/* Structure to hold all of our device specific stuff */
	43	struct usb_skel {
	44	struct usb_device * udev; /* the usb device for this device */
	45	struct usb_interface * interface; /* the interface for this device */
	46	unsigned char * bulk_in_buffer; /* the buffer to receive data */
	47	size_t bulk_in_size; /* the size of the receive buffer */
	48	__u8 bulk_in_endpointAddr; /* the address of the bulk in endpoint */
	49	__u8 bulk_out_endpointAddr; /* the address of the bulk out endpoint */
	50	struct kref kref;
	51	};
	52	#define to_skel_dev(d) container_of(d, struct usb_skel, kref)
	53
	54	static struct usb_driver skel_driver;
	55
	56	static void skel_delete(struct kref *kref)
	57	{
	58	struct usb_skel *dev = to_skel_dev(kref);
	59
	60	usb_put_dev(dev->udev);
	61	kfree (dev->bulk_in_buffer);
	62	kfree (dev);
	63	}
	64
65	static int skel_open(struct inode inode, struct file file)
66	{
67	struct usb_skel *dev;
68	struct usb_interface *interface;
69	int subminor;
70	int retval = 0;
71
72	subminor = iminor(inode);
73
74	interface = usb_find_interface(&skel_driver, subminor);
75	if (!interface) {
76	err ("%s - error, can't find device for minor %d",
77	__FUNCTION__, subminor);
78	retval = -ENODEV;
79	goto exit;
80	}
81
82	dev = usb_get_intfdata(interface);
83	if (!dev) {
84	retval = -ENODEV;
85	goto exit;
86	}
87
88	/* increment our usage count for the device */
89	kref_get(&dev->kref);
90
91	/* save our object in the file's private structure */
92	file->private_data = dev;
93
94	exit:
95	return retval;
96	}
97
98	static int skel_release(struct inode inode, struct file file)
99	{
100	struct usb_skel *dev;
101
102	dev = (struct usb_skel *)file->private_data;
103	if (dev == NULL)
104	return -ENODEV;
105
106	/* decrement the count on our device */
107	kref_put(&dev->kref, skel_delete);
108	return 0;
109	}
110
111	static ssize_t skel_read(struct file file, char buffer, size_t count, loff_t *ppos)
112	{
113	struct usb_skel *dev;
114	int retval = 0;
115	int bytes_read;
116
117	dev = (struct usb_skel *)file->private_data;
118
119	/* do a blocking bulk read to get data from the device */
120	retval = usb_bulk_msg(dev->udev,
121	usb_rcvbulkpipe(dev->udev, dev->bulk_in_endpointAddr),
122	dev->bulk_in_buffer,
123	min(dev->bulk_in_size, count),
124	&bytes_read, 10000);
125
126	/* if the read was successful, copy the data to userspace */
127	if (!retval) {
128	if (copy_to_user(buffer, dev->bulk_in_buffer, bytes_read))
129	retval = -EFAULT;
130	else
131	retval = bytes_read;
132	}
133
134	return retval;
135	}
136
137	static void skel_write_bulk_callback(struct urb urb, struct pt_regs regs)
138	{
139	struct usb_skel *dev;
140
141	dev = (struct usb_skel *)urb->context;
142
143	/* sync/async unlink faults aren't errors */
144	if (urb->status &&
145	!(urb->status == -ENOENT \|\|
146	urb->status == -ECONNRESET \|\|
147	urb->status == -ESHUTDOWN)) {
148	dbg("%s - nonzero write bulk status received: %d",
149	__FUNCTION__, urb->status);
150	}
151
152	/* free up our allocated buffer */
153	usb_buffer_free(urb->dev, urb->transfer_buffer_length,
154	urb->transfer_buffer, urb->transfer_dma);
155	}
156
157	static ssize_t skel_write(struct file file, const char user_buffer, size_t count, loff_t *ppos)
158	{
159	struct usb_skel *dev;
160	int retval = 0;
161	struct urb *urb = NULL;
162	char *buf = NULL;
163
164	dev = (struct usb_skel *)file->private_data;
165
166	/* verify that we actually have some data to write */
167	if (count == 0)
168	goto exit;
169
170	/* create a urb, and a buffer for it, and copy the data to the urb */
171	urb = usb_alloc_urb(0, GFP_KERNEL);
172	if (!urb) {
173	retval = -ENOMEM;
174	goto error;
175	}
176
177	buf = usb_buffer_alloc(dev->udev, count, GFP_KERNEL, &urb->transfer_dma);
178	if (!buf) {
179	retval = -ENOMEM;
180	goto error;
181	}
182
183	if (copy_from_user(buf, user_buffer, count)) {
184	retval = -EFAULT;
185	goto error;
186	}
187
188	/* initialize the urb properly */
189	usb_fill_bulk_urb(urb, dev->udev,
190	usb_sndbulkpipe(dev->udev, dev->bulk_out_endpointAddr),
191	buf, count, skel_write_bulk_callback, dev);
192	urb->transfer_flags \|= URB_NO_TRANSFER_DMA_MAP;
193
194	/* send the data out the bulk port */
195	retval = usb_submit_urb(urb, GFP_KERNEL);
196	if (retval) {
197	err("%s - failed submitting write urb, error %d", __FUNCTION__, retval);
198	goto error;
199	}
200
201	/* release our reference to this urb, the USB core will eventually free it entirely */
202	usb_free_urb(urb);
203
204	exit:
205	return count;
206
207	error:
208	usb_buffer_free(dev->udev, count, buf, urb->transfer_dma);
209	usb_free_urb(urb);
210	return retval;
211	}
212
213	static struct file_operations skel_fops = {
214	.owner = THIS_MODULE,
215	.read = skel_read,
216	.write = skel_write,
217	.open = skel_open,
218	.release = skel_release,
219	};
220
221	/*
222	* usb class driver info in order to get a minor number from the usb core,
223	* and to have the device registered with devfs and the driver core
224	*/
225	static struct usb_class_driver skel_class = {
d6e5bcf4	226	.name = "skel%d",
1da177e4	227	.fops = &skel_fops,
1da177e4 LT	228	.minor_base = USB_SKEL_MINOR_BASE,
	229	};
	230
	231	static int skel_probe(struct usb_interface interface, const struct usb_device_id id)
	232	{
	233	struct usb_skel *dev = NULL;
	234	struct usb_host_interface *iface_desc;
	235	struct usb_endpoint_descriptor *endpoint;
	236	size_t buffer_size;
	237	int i;
	238	int retval = -ENOMEM;
	239
	240	/* allocate memory for our device state and initialize it */
	241	dev = kmalloc(sizeof(*dev), GFP_KERNEL);
	242	if (dev == NULL) {
	243	err("Out of memory");
	244	goto error;
	245	}
	246	memset(dev, 0x00, sizeof(*dev));
	247	kref_init(&dev->kref);
	248
	249	dev->udev = usb_get_dev(interface_to_usbdev(interface));
	250	dev->interface = interface;
	251
	252	/* set up the endpoint information */
	253	/* use only the first bulk-in and bulk-out endpoints */
	254	iface_desc = interface->cur_altsetting;
	255	for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
	256	endpoint = &iface_desc->endpoint[i].desc;
	257
	258	if (!dev->bulk_in_endpointAddr &&
6b216df8 CC	259	((endpoint->bEndpointAddress & USB_ENDPOINT_DIR_MASK)
6b216df8 CC	260	== USB_DIR_IN) &&
1da177e4 LT	261	((endpoint->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK)
	262	== USB_ENDPOINT_XFER_BULK)) {
	263	/* we found a bulk in endpoint */
	264	buffer_size = le16_to_cpu(endpoint->wMaxPacketSize);
	265	dev->bulk_in_size = buffer_size;
	266	dev->bulk_in_endpointAddr = endpoint->bEndpointAddress;
	267	dev->bulk_in_buffer = kmalloc(buffer_size, GFP_KERNEL);
	268	if (!dev->bulk_in_buffer) {
	269	err("Could not allocate bulk_in_buffer");
	270	goto error;
	271	}
	272	}
	273
	274	if (!dev->bulk_out_endpointAddr &&
6b216df8 CC	275	((endpoint->bEndpointAddress & USB_ENDPOINT_DIR_MASK)
6b216df8 CC	276	== USB_DIR_OUT) &&
1da177e4 LT	277	((endpoint->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK)
	278	== USB_ENDPOINT_XFER_BULK)) {
	279	/* we found a bulk out endpoint */
	280	dev->bulk_out_endpointAddr = endpoint->bEndpointAddress;
	281	}
	282	}
	283	if (!(dev->bulk_in_endpointAddr && dev->bulk_out_endpointAddr)) {
	284	err("Could not find both bulk-in and bulk-out endpoints");
	285	goto error;
	286	}
	287
	288	/* save our data pointer in this interface device */
	289	usb_set_intfdata(interface, dev);
	290
	291	/* we can register the device now, as it is ready */
	292	retval = usb_register_dev(interface, &skel_class);
	293	if (retval) {
	294	/* something prevented us from registering this driver */
	295	err("Not able to get a minor for this device.");
	296	usb_set_intfdata(interface, NULL);
	297	goto error;
	298	}
	299
	300	/* let the user know what node this device is now attached to */
	301	info("USB Skeleton device now attached to USBSkel-%d", interface->minor);
	302	return 0;
	303
	304	error:
	305	if (dev)
	306	kref_put(&dev->kref, skel_delete);
	307	return retval;
	308	}
	309
	310	static void skel_disconnect(struct usb_interface *interface)
	311	{
	312	struct usb_skel *dev;
	313	int minor = interface->minor;
	314
	315	/* prevent skel_open() from racing skel_disconnect() */
	316	lock_kernel();
	317
	318	dev = usb_get_intfdata(interface);
	319	usb_set_intfdata(interface, NULL);
	320
	321	/* give back our minor */
	322	usb_deregister_dev(interface, &skel_class);
	323
	324	unlock_kernel();
	325
	326	/* decrement our usage count */
	327	kref_put(&dev->kref, skel_delete);
	328
	329	info("USB Skeleton #%d now disconnected", minor);
	330	}
	331
	332	static struct usb_driver skel_driver = {
1da177e4 LT	333	.name = "skeleton",
	334	.probe = skel_probe,
	335	.disconnect = skel_disconnect,
	336	.id_table = skel_table,
	337	};
	338
	339	static int __init usb_skel_init(void)
	340	{
	341	int result;
	342
	343	/* register this driver with the USB subsystem */
	344	result = usb_register(&skel_driver);
	345	if (result)
	346	err("usb_register failed. Error number %d", result);
	347
	348	return result;
	349	}
	350
	351	static void __exit usb_skel_exit(void)
	352	{
	353	/* deregister this driver with the USB subsystem */
	354	usb_deregister(&skel_driver);
	355	}
	356
	357	module_init (usb_skel_init);
	358	module_exit (usb_skel_exit);
	359
	360	MODULE_LICENSE("GPL");