453 lines
12 KiB
C
453 lines
12 KiB
C
/*****************************************************************************
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* USBLCD Kernel Driver *
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* Version 1.05 *
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* (C) 2005 Georges Toth <g.toth@e-biz.lu> *
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* *
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* This file is licensed under the GPL. See COPYING in the package. *
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* Based on usb-skeleton.c 2.0 by Greg Kroah-Hartman (greg@kroah.com) *
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* *
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* *
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* 28.02.05 Complete rewrite of the original usblcd.c driver, *
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* based on usb_skeleton.c. *
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* This new driver allows more than one USB-LCD to be connected *
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* and controlled, at once *
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*****************************************************************************/
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#include <linux/module.h>
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#include <linux/kernel.h>
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#include <linux/init.h>
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#include <linux/slab.h>
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#include <linux/errno.h>
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#include <linux/mutex.h>
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#include <asm/uaccess.h>
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#include <linux/usb.h>
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#define DRIVER_VERSION "USBLCD Driver Version 1.05"
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#define USBLCD_MINOR 144
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#define IOCTL_GET_HARD_VERSION 1
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#define IOCTL_GET_DRV_VERSION 2
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static struct usb_device_id id_table [] = {
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{ .idVendor = 0x10D2, .match_flags = USB_DEVICE_ID_MATCH_VENDOR, },
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{ },
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};
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MODULE_DEVICE_TABLE (usb, id_table);
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static DEFINE_MUTEX(open_disc_mutex);
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struct usb_lcd {
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struct usb_device * udev; /* init: probe_lcd */
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struct usb_interface * interface; /* the interface for this device */
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unsigned char * bulk_in_buffer; /* the buffer to receive data */
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size_t bulk_in_size; /* the size of the receive buffer */
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__u8 bulk_in_endpointAddr; /* the address of the bulk in endpoint */
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__u8 bulk_out_endpointAddr; /* the address of the bulk out endpoint */
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struct kref kref;
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struct semaphore limit_sem; /* to stop writes at full throttle from
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* using up all RAM */
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struct usb_anchor submitted; /* URBs to wait for before suspend */
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};
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#define to_lcd_dev(d) container_of(d, struct usb_lcd, kref)
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#define USB_LCD_CONCURRENT_WRITES 5
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static struct usb_driver lcd_driver;
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static void lcd_delete(struct kref *kref)
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{
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struct usb_lcd *dev = to_lcd_dev(kref);
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usb_put_dev(dev->udev);
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kfree (dev->bulk_in_buffer);
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kfree (dev);
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}
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static int lcd_open(struct inode *inode, struct file *file)
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{
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struct usb_lcd *dev;
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struct usb_interface *interface;
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int subminor, r;
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subminor = iminor(inode);
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interface = usb_find_interface(&lcd_driver, subminor);
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if (!interface) {
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err ("USBLCD: %s - error, can't find device for minor %d",
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__func__, subminor);
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return -ENODEV;
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}
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mutex_lock(&open_disc_mutex);
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dev = usb_get_intfdata(interface);
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if (!dev) {
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mutex_unlock(&open_disc_mutex);
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return -ENODEV;
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}
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/* increment our usage count for the device */
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kref_get(&dev->kref);
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mutex_unlock(&open_disc_mutex);
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/* grab a power reference */
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r = usb_autopm_get_interface(interface);
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if (r < 0) {
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kref_put(&dev->kref, lcd_delete);
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return r;
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}
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/* save our object in the file's private structure */
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file->private_data = dev;
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return 0;
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}
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static int lcd_release(struct inode *inode, struct file *file)
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{
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struct usb_lcd *dev;
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dev = (struct usb_lcd *)file->private_data;
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if (dev == NULL)
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return -ENODEV;
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/* decrement the count on our device */
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usb_autopm_put_interface(dev->interface);
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kref_put(&dev->kref, lcd_delete);
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return 0;
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}
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static ssize_t lcd_read(struct file *file, char __user * buffer, size_t count, loff_t *ppos)
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{
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struct usb_lcd *dev;
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int retval = 0;
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int bytes_read;
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dev = (struct usb_lcd *)file->private_data;
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/* do a blocking bulk read to get data from the device */
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retval = usb_bulk_msg(dev->udev,
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usb_rcvbulkpipe(dev->udev, dev->bulk_in_endpointAddr),
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dev->bulk_in_buffer,
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min(dev->bulk_in_size, count),
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&bytes_read, 10000);
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/* if the read was successful, copy the data to userspace */
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if (!retval) {
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if (copy_to_user(buffer, dev->bulk_in_buffer, bytes_read))
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retval = -EFAULT;
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else
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retval = bytes_read;
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}
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return retval;
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}
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static long lcd_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
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{
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struct usb_lcd *dev;
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u16 bcdDevice;
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char buf[30];
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dev = (struct usb_lcd *)file->private_data;
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if (dev == NULL)
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return -ENODEV;
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switch (cmd) {
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case IOCTL_GET_HARD_VERSION:
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lock_kernel();
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bcdDevice = le16_to_cpu((dev->udev)->descriptor.bcdDevice);
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sprintf(buf,"%1d%1d.%1d%1d",
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(bcdDevice & 0xF000)>>12,
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(bcdDevice & 0xF00)>>8,
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(bcdDevice & 0xF0)>>4,
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(bcdDevice & 0xF));
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unlock_kernel();
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if (copy_to_user((void __user *)arg,buf,strlen(buf))!=0)
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return -EFAULT;
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break;
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case IOCTL_GET_DRV_VERSION:
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sprintf(buf,DRIVER_VERSION);
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if (copy_to_user((void __user *)arg,buf,strlen(buf))!=0)
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return -EFAULT;
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break;
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default:
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return -ENOTTY;
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break;
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}
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return 0;
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}
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static void lcd_write_bulk_callback(struct urb *urb)
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{
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struct usb_lcd *dev;
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int status = urb->status;
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dev = urb->context;
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/* sync/async unlink faults aren't errors */
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if (status &&
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!(status == -ENOENT ||
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status == -ECONNRESET ||
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status == -ESHUTDOWN)) {
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dbg("USBLCD: %s - nonzero write bulk status received: %d",
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__func__, status);
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}
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/* free up our allocated buffer */
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usb_buffer_free(urb->dev, urb->transfer_buffer_length,
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urb->transfer_buffer, urb->transfer_dma);
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up(&dev->limit_sem);
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}
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static ssize_t lcd_write(struct file *file, const char __user * user_buffer, size_t count, loff_t *ppos)
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{
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struct usb_lcd *dev;
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int retval = 0, r;
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struct urb *urb = NULL;
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char *buf = NULL;
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dev = (struct usb_lcd *)file->private_data;
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/* verify that we actually have some data to write */
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if (count == 0)
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goto exit;
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r = down_interruptible(&dev->limit_sem);
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if (r < 0)
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return -EINTR;
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/* create a urb, and a buffer for it, and copy the data to the urb */
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urb = usb_alloc_urb(0, GFP_KERNEL);
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if (!urb) {
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retval = -ENOMEM;
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goto err_no_buf;
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}
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buf = usb_buffer_alloc(dev->udev, count, GFP_KERNEL, &urb->transfer_dma);
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if (!buf) {
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retval = -ENOMEM;
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goto error;
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}
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if (copy_from_user(buf, user_buffer, count)) {
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retval = -EFAULT;
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goto error;
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}
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/* initialize the urb properly */
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usb_fill_bulk_urb(urb, dev->udev,
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usb_sndbulkpipe(dev->udev, dev->bulk_out_endpointAddr),
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buf, count, lcd_write_bulk_callback, dev);
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urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
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usb_anchor_urb(urb, &dev->submitted);
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/* send the data out the bulk port */
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retval = usb_submit_urb(urb, GFP_KERNEL);
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if (retval) {
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err("USBLCD: %s - failed submitting write urb, error %d", __func__, retval);
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goto error_unanchor;
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}
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/* release our reference to this urb, the USB core will eventually free it entirely */
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usb_free_urb(urb);
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exit:
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return count;
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error_unanchor:
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usb_unanchor_urb(urb);
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error:
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usb_buffer_free(dev->udev, count, buf, urb->transfer_dma);
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usb_free_urb(urb);
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err_no_buf:
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up(&dev->limit_sem);
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return retval;
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}
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static const struct file_operations lcd_fops = {
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.owner = THIS_MODULE,
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.read = lcd_read,
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.write = lcd_write,
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.open = lcd_open,
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.unlocked_ioctl = lcd_ioctl,
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.release = lcd_release,
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};
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/*
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* usb class driver info in order to get a minor number from the usb core,
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* and to have the device registered with the driver core
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*/
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static struct usb_class_driver lcd_class = {
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.name = "lcd%d",
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.fops = &lcd_fops,
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.minor_base = USBLCD_MINOR,
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};
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static int lcd_probe(struct usb_interface *interface, const struct usb_device_id *id)
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{
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struct usb_lcd *dev = NULL;
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struct usb_host_interface *iface_desc;
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struct usb_endpoint_descriptor *endpoint;
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size_t buffer_size;
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int i;
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int retval = -ENOMEM;
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/* allocate memory for our device state and initialize it */
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dev = kzalloc(sizeof(*dev), GFP_KERNEL);
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if (dev == NULL) {
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err("Out of memory");
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goto error;
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}
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kref_init(&dev->kref);
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sema_init(&dev->limit_sem, USB_LCD_CONCURRENT_WRITES);
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init_usb_anchor(&dev->submitted);
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dev->udev = usb_get_dev(interface_to_usbdev(interface));
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dev->interface = interface;
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if (le16_to_cpu(dev->udev->descriptor.idProduct) != 0x0001) {
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dev_warn(&interface->dev, "USBLCD model not supported.\n");
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return -ENODEV;
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}
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/* set up the endpoint information */
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/* use only the first bulk-in and bulk-out endpoints */
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iface_desc = interface->cur_altsetting;
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for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
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endpoint = &iface_desc->endpoint[i].desc;
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if (!dev->bulk_in_endpointAddr &&
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usb_endpoint_is_bulk_in(endpoint)) {
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/* we found a bulk in endpoint */
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buffer_size = le16_to_cpu(endpoint->wMaxPacketSize);
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dev->bulk_in_size = buffer_size;
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dev->bulk_in_endpointAddr = endpoint->bEndpointAddress;
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dev->bulk_in_buffer = kmalloc(buffer_size, GFP_KERNEL);
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if (!dev->bulk_in_buffer) {
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err("Could not allocate bulk_in_buffer");
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goto error;
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}
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}
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if (!dev->bulk_out_endpointAddr &&
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usb_endpoint_is_bulk_out(endpoint)) {
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/* we found a bulk out endpoint */
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dev->bulk_out_endpointAddr = endpoint->bEndpointAddress;
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}
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}
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if (!(dev->bulk_in_endpointAddr && dev->bulk_out_endpointAddr)) {
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err("Could not find both bulk-in and bulk-out endpoints");
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goto error;
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}
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/* save our data pointer in this interface device */
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usb_set_intfdata(interface, dev);
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/* we can register the device now, as it is ready */
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retval = usb_register_dev(interface, &lcd_class);
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if (retval) {
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/* something prevented us from registering this driver */
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err("Not able to get a minor for this device.");
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usb_set_intfdata(interface, NULL);
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goto error;
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}
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i = le16_to_cpu(dev->udev->descriptor.bcdDevice);
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dev_info(&interface->dev, "USBLCD Version %1d%1d.%1d%1d found "
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"at address %d\n", (i & 0xF000)>>12, (i & 0xF00)>>8,
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(i & 0xF0)>>4,(i & 0xF), dev->udev->devnum);
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/* let the user know what node this device is now attached to */
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dev_info(&interface->dev, "USB LCD device now attached to USBLCD-%d\n",
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interface->minor);
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return 0;
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error:
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if (dev)
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kref_put(&dev->kref, lcd_delete);
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return retval;
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}
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static void lcd_draw_down(struct usb_lcd *dev)
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{
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int time;
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time = usb_wait_anchor_empty_timeout(&dev->submitted, 1000);
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if (!time)
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usb_kill_anchored_urbs(&dev->submitted);
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}
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static int lcd_suspend(struct usb_interface *intf, pm_message_t message)
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{
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struct usb_lcd *dev = usb_get_intfdata(intf);
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if (!dev)
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return 0;
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lcd_draw_down(dev);
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return 0;
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}
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static int lcd_resume (struct usb_interface *intf)
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{
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return 0;
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}
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static void lcd_disconnect(struct usb_interface *interface)
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{
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struct usb_lcd *dev;
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int minor = interface->minor;
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mutex_lock(&open_disc_mutex);
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dev = usb_get_intfdata(interface);
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usb_set_intfdata(interface, NULL);
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mutex_unlock(&open_disc_mutex);
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/* give back our minor */
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usb_deregister_dev(interface, &lcd_class);
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/* decrement our usage count */
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kref_put(&dev->kref, lcd_delete);
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dev_info(&interface->dev, "USB LCD #%d now disconnected\n", minor);
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}
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static struct usb_driver lcd_driver = {
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.name = "usblcd",
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.probe = lcd_probe,
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.disconnect = lcd_disconnect,
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.suspend = lcd_suspend,
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.resume = lcd_resume,
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.id_table = id_table,
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.supports_autosuspend = 1,
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};
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static int __init usb_lcd_init(void)
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{
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int result;
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result = usb_register(&lcd_driver);
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if (result)
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err("usb_register failed. Error number %d", result);
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return result;
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}
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static void __exit usb_lcd_exit(void)
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{
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usb_deregister(&lcd_driver);
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}
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module_init(usb_lcd_init);
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module_exit(usb_lcd_exit);
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MODULE_AUTHOR("Georges Toth <g.toth@e-biz.lu>");
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MODULE_DESCRIPTION(DRIVER_VERSION);
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MODULE_LICENSE("GPL");
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