patch-2.4.7 linux/drivers/usb/usb-skeleton.c

• Lines: 653
• Date: Wed Jul 4 15:43:05 2001
• Orig file: v2.4.6/linux/drivers/usb/usb-skeleton.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.4.6/linux/drivers/usb/usb-skeleton.c linux/drivers/usb/usb-skeleton.c
@@ -0,0 +1,652 @@
+/*
+ * USB Skeleton driver
+ *
+ * Copyright (c) 2001 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; either version 2 of
+ *	the License, or (at your option) any later version.
+ *
+ *
+ * This driver is to be used as a skeleton driver to be able to create a
+ * USB driver quickly.  The design of it is based on the usb-serial and
+ * dc2xx drivers.
+ *
+ * Thanks to Oliver Neukum and David Brownell for their help in debugging
+ * this driver.
+ *
+ * TODO:
+ *	- fix urb->status race condition in write sequence
+ *	- move minor_table to a dynamic list.
+ *
+ * History:
+ *
+ * 2001_05_29 - 0.3 - more bug fixes based on review from linux-usb-devel
+ * 2001_05_24 - 0.2 - bug fixes based on review from linux-usb-devel people
+ * 2001_05_01 - 0.1 - first version
+ * 
+ */
+
+#include <linux/config.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/signal.h>
+#include <linux/errno.h>
+#include <linux/poll.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/fcntl.h>
+#include <linux/module.h>
+#include <linux/spinlock.h>
+#include <linux/list.h>
+#include <linux/smp_lock.h>
+#include <linux/devfs_fs_kernel.h>
+#include <linux/usb.h>
+
+#ifdef CONFIG_USB_DEBUG
+	static int debug = 1;
+#else
+	static int debug;
+#endif
+
+/* Use our own dbg macro */
+#undef dbg
+#define dbg(format, arg...) do { if (debug) printk(KERN_DEBUG __FILE__ ": " format "\n" , ## arg); } while (0)
+
+
+/* Version Information */
+#define DRIVER_VERSION "v0.3"
+#define DRIVER_AUTHOR "Greg Kroah-Hartman, greg@kroah.com"
+#define DRIVER_DESC "USB Skeleton Driver"
+
+/* Module paramaters */
+MODULE_PARM(debug, "i");
+MODULE_PARM_DESC(debug, "Debug enabled or not");
+
+
+/* Define these values to match your device */
+#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	200	
+
+/* we can have up to this number of device plugged in at once */
+#define MAX_DEVICES		16
+
+/* Structure to hold all of our device specific stuff */
+struct usb_skel {
+	struct usb_device *	udev;			/* save off the usb device pointer */
+	struct usb_interface *	interface;		/* the interface for this device */
+	devfs_handle_t		devfs;			/* devfs device node */
+	unsigned char		minor;			/* the starting minor number for this device */
+	unsigned char		num_ports;		/* the number of ports this device has */
+	char			num_interrupt_in;	/* number of interrupt in endpoints we have */
+	char			num_bulk_in;		/* number of bulk in endpoints we have */
+	char			num_bulk_out;		/* number of bulk out endpoints we have */
+
+	unsigned char *		bulk_in_buffer;		/* the buffer to receive data */
+	int			bulk_in_size;		/* the size of the receive buffer */
+	__u8			bulk_in_endpointAddr;	/* the address of the bulk in endpoint */
+
+	unsigned char *		bulk_out_buffer;	/* the buffer to send data */
+	int			bulk_out_size;		/* the size of the send buffer */
+	struct urb *		write_urb;		/* the urb used to send data */
+	__u8			bulk_out_endpointAddr;	/* the address of the bulk out endpoint */
+
+	struct tq_struct	tqueue;			/* task queue for line discipline waking up */
+	int			open_count;		/* number of times this port has been opened */
+	struct semaphore	sem;			/* locks this structure */
+};
+
+
+/* the global usb devfs handle */
+extern devfs_handle_t usb_devfs_handle;
+
+
+/* local function prototypes */
+static ssize_t skel_read	(struct file *file, char *buffer, size_t count, loff_t *ppos);
+static ssize_t skel_write	(struct file *file, const char *buffer, size_t count, loff_t *ppos);
+static int skel_ioctl		(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg);
+static int skel_open		(struct inode *inode, struct file *file);
+static int skel_release		(struct inode *inode, struct file *file);
+	
+static void * skel_probe	(struct usb_device *dev, unsigned int ifnum, const struct usb_device_id *id);
+static void skel_disconnect	(struct usb_device *dev, void *ptr);
+
+static void skel_write_bulk_callback	(struct urb *urb);
+
+
+/* array of pointers to our devices that are currently connected */
+static struct usb_skel		*minor_table[MAX_DEVICES];
+
+/* lock to protect the minor_table structure */
+static DECLARE_MUTEX (minor_table_mutex);
+
+/* file operations needed when we register this driver */
+static struct file_operations skel_fops = {
+	owner:		THIS_MODULE,
+	read:		skel_read,
+	write:		skel_write,
+	ioctl:		skel_ioctl,
+	open:		skel_open,
+	release:	skel_release,
+};      
+
+
+/* usb specific object needed to register this driver with the usb subsystem */
+static struct usb_driver skel_driver = {
+	name:		"skeleton",
+	probe:		skel_probe,
+	disconnect:	skel_disconnect,
+	fops:		&skel_fops,
+	minor:		USB_SKEL_MINOR_BASE,
+	id_table:	skel_table,
+};
+
+
+
+
+
+/**
+ *	usb_skel_debug_data
+ */
+static inline void usb_skel_debug_data (const char *function, int size, const unsigned char *data)
+{
+	int i;
+
+	if (!debug)
+		return;
+	
+	printk (KERN_DEBUG __FILE__": %s - length = %d, data = ", 
+		function, size);
+	for (i = 0; i < size; ++i) {
+		printk ("%.2x ", data[i]);
+	}
+	printk ("\n");
+}
+
+
+/**
+ *	skel_open
+ */
+static int skel_open (struct inode *inode, struct file *file)
+{
+	struct usb_skel *dev = NULL;
+	int subminor;
+	int retval = 0;
+	
+	dbg(__FUNCTION__);
+
+	subminor = MINOR (inode->i_rdev) - USB_SKEL_MINOR_BASE;
+	if ((subminor < 0) ||
+	    (subminor >= MAX_DEVICES)) {
+		return -ENODEV;
+	}
+
+	/* increment our usage count for the module */
+	MOD_INC_USE_COUNT;
+
+	/* lock our minor table and get our local data for this minor */
+	down (&minor_table_mutex);
+	dev = minor_table[subminor];
+	if (dev == NULL) {
+		up (&minor_table_mutex);
+		MOD_DEC_USE_COUNT;
+		return -ENODEV;
+	}
+
+	/* lock this device */
+	down (&dev->sem);
+
+	/* unlock the minor table */
+	up (&minor_table_mutex);
+
+	/* increment our usage count for the driver */
+	++dev->open_count;
+
+	/* save our object in the file's private structure */
+	file->private_data = dev;
+
+	/* unlock this device */
+	up (&dev->sem);
+
+	return retval;
+}
+
+
+/**
+ *	skel_release
+ */
+static int skel_release (struct inode *inode, struct file *file)
+{
+	struct usb_skel *dev;
+	int retval = 0;
+
+	dev = (struct usb_skel *)file->private_data;
+	if (dev == NULL) {
+		dbg (__FUNCTION__ " - object is NULL");
+		return -ENODEV;
+	}
+
+	dbg(__FUNCTION__ " - minor %d", dev->minor);
+
+	/* lock our minor table */
+	down (&minor_table_mutex);
+
+	/* lock our device */
+	down (&dev->sem);
+
+	if (dev->open_count <= 0) {
+		dbg (__FUNCTION__ " - device not opened");
+		retval = -ENODEV;
+		goto exit_not_opened;
+	}
+
+	if (dev->udev == NULL) {
+		/* the device was unplugged before the file was released */
+		minor_table[dev->minor] = NULL;
+		if (dev->bulk_in_buffer != NULL)
+			kfree (dev->bulk_in_buffer);
+		if (dev->bulk_out_buffer != NULL)
+			kfree (dev->bulk_out_buffer);
+		if (dev->write_urb != NULL)
+			usb_free_urb (dev->write_urb);
+		kfree (dev);
+		goto exit;
+	}
+
+	/* decrement our usage count for the device */
+	--dev->open_count;
+	if (dev->open_count <= 0) {
+		/* shutdown any bulk writes that might be going on */
+		dev->write_urb->transfer_flags |= USB_ASYNC_UNLINK;
+		usb_unlink_urb (dev->write_urb);
+		dev->open_count = 0;
+	}
+
+exit:
+	/* decrement our usage count for the module */
+	MOD_DEC_USE_COUNT;
+
+exit_not_opened:
+	up (&dev->sem);
+	up (&minor_table_mutex);
+
+	return retval;
+}
+
+
+/**
+ *	skel_read
+ */
+static ssize_t skel_read (struct file *file, char *buffer, size_t count, loff_t *ppos)
+{
+	struct usb_skel *dev;
+	int retval = 0;
+
+	dev = (struct usb_skel *)file->private_data;
+	
+	dbg(__FUNCTION__ " - minor %d, count = %d", dev->minor, count);
+
+	/* lock this object */
+	down (&dev->sem);
+
+	/* verify that the device wasn't unplugged */
+	if (dev->udev == NULL) {
+		up (&dev->sem);
+		return -ENODEV;
+	}
+	
+	/* do an immediate 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, dev->bulk_in_size,
+			       &count, HZ*10);
+
+	/* if the read was successful, copy the data to userspace */
+	if (!retval) {
+		if (copy_to_user (buffer, dev->bulk_in_buffer, count))
+			retval = -EFAULT;
+		else
+			retval = count;
+	}
+	
+	/* unlock the device */
+	up (&dev->sem);
+	return retval;
+}
+
+
+/**
+ *	skel_write
+ */
+static ssize_t skel_write (struct file *file, const char *buffer, size_t count, loff_t *ppos)
+{
+	struct usb_skel *dev;
+	ssize_t bytes_written = 0;
+	int retval = 0;
+
+	dev = (struct usb_skel *)file->private_data;
+
+	dbg(__FUNCTION__ " - minor %d, count = %d", dev->minor, count);
+
+	/* lock this object */
+	down (&dev->sem);
+
+	/* verify that the device wasn't unplugged */
+	if (dev->udev == NULL) {
+		retval = -ENODEV;
+		goto exit;
+	}
+
+	/* verify that we actually have some data to write */
+	if (count == 0) {
+		dbg(__FUNCTION__ " - write request of 0 bytes");
+		goto exit;
+	}
+
+	/* see if we are already in the middle of a write */
+	if (dev->write_urb->status == -EINPROGRESS) {
+		dbg (__FUNCTION__ " - already writing");
+		goto exit;
+	}
+
+	/* we can only write as much as 1 urb will hold */
+	bytes_written = (count > dev->bulk_out_size) ? 
+				dev->bulk_out_size : count;
+
+	/* copy the data from userspace into our urb */
+	if (copy_from_user(dev->write_urb->transfer_buffer, buffer, 
+			   bytes_written)) {
+		retval = -EFAULT;
+		goto exit;
+	}
+
+	usb_skel_debug_data (__FUNCTION__, bytes_written, 
+			     dev->write_urb->transfer_buffer);
+
+	/* set up our urb */
+	FILL_BULK_URB(dev->write_urb, dev->udev, 
+		      usb_sndbulkpipe(dev->udev, dev->bulk_out_endpointAddr),
+		      dev->write_urb->transfer_buffer, bytes_written,
+		      skel_write_bulk_callback, dev);
+
+	/* send the data out the bulk port */
+	retval = usb_submit_urb(dev->write_urb);
+	if (retval) {
+		err(__FUNCTION__ " - failed submitting write urb, error %d",
+		    retval);
+	} else {
+		retval = bytes_written;
+	}
+
+exit:
+	/* unlock the device */
+	up (&dev->sem);
+
+	return retval;
+}
+
+
+/**
+ *	skel_ioctl
+ */
+static int skel_ioctl (struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
+{
+	struct usb_skel *dev;
+
+	dev = (struct usb_skel *)file->private_data;
+
+	/* lock this object */
+	down (&dev->sem);
+
+	/* verify that the device wasn't unplugged */
+	if (dev->udev == NULL) {
+		up (&dev->sem);
+		return -ENODEV;
+	}
+
+	dbg(__FUNCTION__ " - minor %d, cmd 0x%.4x, arg %ld", 
+	    dev->minor, cmd, arg);
+
+
+	/* fill in your device specific stuff here */
+	
+	/* unlock the device */
+	up (&dev->sem);
+	
+	/* return that we did not understand this ioctl call */
+	return -ENOTTY;
+}
+
+
+/**
+ *	skel_write_bulk_callback
+ */
+static void skel_write_bulk_callback (struct urb *urb)
+{
+	struct usb_skel *dev = (struct usb_skel *)urb->context;
+
+	dbg(__FUNCTION__ " - minor %d", dev->minor);
+
+	if ((urb->status != -ENOENT) && 
+	    (urb->status != -ECONNRESET)) {
+		dbg(__FUNCTION__ " - nonzero write bulk status received: %d",
+		    urb->status);
+		return;
+	}
+
+	return;
+}
+
+
+
+
+
+static void * skel_probe(struct usb_device *udev, unsigned int ifnum, const struct usb_device_id *id)
+{
+	struct usb_skel *dev = NULL;
+	struct usb_interface *interface;
+	struct usb_interface_descriptor *iface_desc;
+	struct usb_endpoint_descriptor *endpoint;
+	int minor;
+	int buffer_size;
+	int i;
+	char name[10];
+
+	
+	/* See if the device offered us matches what we can accept */
+	if ((udev->descriptor.idVendor != USB_SKEL_VENDOR_ID) ||
+	    (udev->descriptor.idProduct != USB_SKEL_PRODUCT_ID)) {
+		return NULL;
+	}
+
+	/* select a "subminor" number (part of a minor number) */
+	down (&minor_table_mutex);
+	for (minor = 0; minor < MAX_DEVICES; i++) {
+		if (minor_table[minor] == NULL)
+			break;
+	}
+	if (minor >= MAX_DEVICES) {
+		info ("Too many devices plugged in, can not handle this device.");
+		goto exit;
+	}
+
+	/* allocate memory for our device state and intialize it */
+	dev = kmalloc (sizeof(struct usb_skel), GFP_KERNEL);
+	if (dev == NULL) {
+		err ("Out of memory");
+		goto exit;
+	}
+	minor_table[minor] = dev;
+
+	interface = &udev->actconfig->interface[ifnum];
+
+	init_MUTEX (&dev->sem);
+	dev->udev = udev;
+	dev->interface = interface;
+	dev->minor = minor;
+
+	/* set up the endpoint information */
+	/* check out the endpoints */
+	iface_desc = &interface->altsetting[0];
+	for (i = 0; i < iface_desc->bNumEndpoints; ++i) {
+		endpoint = &iface_desc->endpoint[i];
+
+		if ((endpoint->bEndpointAddress & 0x80) &&
+		    ((endpoint->bmAttributes & 3) == 0x02)) {
+			/* we found a bulk in endpoint */
+			buffer_size = 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("Couldn't allocate bulk_in_buffer");
+				goto error;
+			}
+		}
+		
+		if (((endpoint->bEndpointAddress & 0x80) == 0x00) &&
+		    ((endpoint->bmAttributes & 3) == 0x02)) {
+			/* we found a bulk out endpoint */
+			dev->write_urb = usb_alloc_urb(0);
+			if (!dev->write_urb) {
+				err("No free urbs available");
+				goto error;
+			}
+			buffer_size = endpoint->wMaxPacketSize;
+			dev->bulk_out_size = buffer_size;
+			dev->bulk_out_endpointAddr = endpoint->bEndpointAddress;
+			dev->bulk_out_buffer = kmalloc (buffer_size, GFP_KERNEL);
+			if (!dev->bulk_out_buffer) {
+				err("Couldn't allocate bulk_out_buffer");
+				goto error;
+			}
+			FILL_BULK_URB(dev->write_urb, udev, 
+				      usb_sndbulkpipe(udev, 
+						      endpoint->bEndpointAddress),
+				      dev->bulk_out_buffer, buffer_size,
+				      skel_write_bulk_callback, dev);
+		}
+	}
+
+	/* initialize the devfs node for this device and register it */
+	sprintf(name, "skel%d", dev->minor);
+	
+	dev->devfs = devfs_register (usb_devfs_handle, name,
+				     DEVFS_FL_DEFAULT, USB_MAJOR,
+				     USB_SKEL_MINOR_BASE + dev->minor,
+				     S_IFCHR | S_IRUSR | S_IWUSR | 
+				     S_IRGRP | S_IWGRP | S_IROTH, 
+				     &skel_fops, NULL);
+
+	/* let the user know what node this device is now attached to */
+	info ("USB Skeleton device now attached to USBSkel%d", dev->minor);
+	goto exit;
+	
+error:
+	minor_table [dev->minor] = NULL;
+	if (dev->bulk_in_buffer != NULL)
+		kfree (dev->bulk_in_buffer);
+	if (dev->bulk_out_buffer != NULL)
+		kfree (dev->bulk_out_buffer);
+	if (dev->write_urb != NULL)
+		usb_free_urb (dev->write_urb);
+	kfree (dev);
+	dev = NULL;
+
+exit:
+	up (&minor_table_mutex);
+	return dev;
+}
+
+
+/**
+ *	skel_disconnect
+ */
+static void skel_disconnect(struct usb_device *udev, void *ptr)
+{
+	struct usb_skel *dev;
+	int minor;
+
+	dev = (struct usb_skel *)ptr;
+	
+	down (&minor_table_mutex);
+	down (&dev->sem);
+		
+	minor = dev->minor;
+
+	/* if the device is not opened, then we clean up right now */
+	if (!dev->open_count) {
+		minor_table[dev->minor] = NULL;
+		if (dev->bulk_in_buffer != NULL)
+			kfree (dev->bulk_in_buffer);
+		if (dev->bulk_out_buffer != NULL)
+			kfree (dev->bulk_out_buffer);
+		if (dev->write_urb != NULL)
+			usb_free_urb (dev->write_urb);
+		kfree (dev);
+	} else {
+		dev->udev = NULL;
+		up (&dev->sem);
+	}
+
+	/* remove our devfs node */
+	devfs_unregister(dev->devfs);
+
+	info("USB Skeleton #%d now disconnected", minor);
+	up (&minor_table_mutex);
+}
+
+
+
+/**
+ *	usb_skel_init
+ */
+static int __init usb_skel_init(void)
+{
+	int result;
+
+	/* register this driver with the USB subsystem */
+	result = usb_register(&skel_driver);
+	if (result < 0) {
+		err("usb_register failed for the "__FILE__" driver. Error number %d",
+		    result);
+		return -1;
+	}
+
+	info(DRIVER_VERSION " " DRIVER_AUTHOR);
+	info(DRIVER_DESC);
+	return 0;
+}
+
+
+/**
+ *	usb_skel_exit
+ */
+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_AUTHOR(DRIVER_AUTHOR);
+MODULE_DESCRIPTION(DRIVER_DESC);
+