451 строка
11 KiB
C
451 строка
11 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*****************************************************************************
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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/slab.h>
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#include <linux/errno.h>
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#include <linux/mutex.h>
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#include <linux/rwsem.h>
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#include <linux/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 const 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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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
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this device */
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unsigned char *bulk_in_buffer; /* the buffer to receive
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data */
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size_t bulk_in_size; /* the size of the
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receive buffer */
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__u8 bulk_in_endpointAddr; /* the address of the
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bulk in endpoint */
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__u8 bulk_out_endpointAddr; /* the address of the
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bulk out endpoint */
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struct kref kref;
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struct semaphore limit_sem; /* to stop writes at
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full throttle from
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using up all RAM */
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struct usb_anchor submitted; /* URBs to wait for
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before suspend */
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struct rw_semaphore io_rwsem;
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unsigned long disconnected:1;
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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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pr_err("USBLCD: %s - error, can't find device for minor %d\n",
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__func__, subminor);
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return -ENODEV;
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}
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dev = usb_get_intfdata(interface);
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/* increment our usage count for the device */
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kref_get(&dev->kref);
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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 = 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,
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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 = file->private_data;
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down_read(&dev->io_rwsem);
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if (dev->disconnected) {
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retval = -ENODEV;
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goto out_up_io;
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}
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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,
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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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out_up_io:
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up_read(&dev->io_rwsem);
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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 = 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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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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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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}
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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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dev_dbg(&dev->interface->dev,
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"nonzero write bulk status received: %d\n", status);
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}
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/* free up our allocated buffer */
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usb_free_coherent(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,
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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 = 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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down_read(&dev->io_rwsem);
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if (dev->disconnected) {
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retval = -ENODEV;
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goto err_up_io;
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}
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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_up_io;
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}
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buf = usb_alloc_coherent(dev->udev, count, GFP_KERNEL,
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&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,
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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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dev_err(&dev->udev->dev,
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"%s - failed submitting write urb, error %d\n",
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__func__, retval);
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goto error_unanchor;
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}
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/* release our reference to this urb,
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the USB core will eventually free it entirely */
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usb_free_urb(urb);
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up_read(&dev->io_rwsem);
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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_free_coherent(dev->udev, count, buf, urb->transfer_dma);
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usb_free_urb(urb);
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err_up_io:
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up_read(&dev->io_rwsem);
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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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.llseek = noop_llseek,
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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,
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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_endpoint_descriptor *bulk_in, *bulk_out;
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int i;
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int retval;
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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)
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return -ENOMEM;
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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_rwsem(&dev->io_rwsem);
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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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retval = -ENODEV;
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goto error;
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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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retval = usb_find_common_endpoints(interface->cur_altsetting,
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&bulk_in, &bulk_out, NULL, NULL);
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if (retval) {
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dev_err(&interface->dev,
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"Could not find both bulk-in and bulk-out endpoints\n");
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goto error;
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}
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dev->bulk_in_size = usb_endpoint_maxp(bulk_in);
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dev->bulk_in_endpointAddr = bulk_in->bEndpointAddress;
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dev->bulk_in_buffer = kmalloc(dev->bulk_in_size, GFP_KERNEL);
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if (!dev->bulk_in_buffer) {
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retval = -ENOMEM;
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goto error;
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}
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dev->bulk_out_endpointAddr = bulk_out->bEndpointAddress;
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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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dev_err(&interface->dev,
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"Not able to get a minor for this device.\n");
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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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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 = usb_get_intfdata(interface);
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int minor = interface->minor;
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/* give back our minor */
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usb_deregister_dev(interface, &lcd_class);
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down_write(&dev->io_rwsem);
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dev->disconnected = 1;
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up_write(&dev->io_rwsem);
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usb_kill_anchored_urbs(&dev->submitted);
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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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module_usb_driver(lcd_driver);
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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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