drivers/usb/serial/ezusb.c

   1 /*
   2  * EZ-USB specific functions used by some of the USB to Serial drivers.
   3  *
   4  * Copyright (C) 1999 - 2002 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 version
   8  *      2 as published by the Free Software Foundation.
   9  */
  10
  11 #include <linux/kernel.h>
  12 #include <linux/errno.h>
  13 #include <linux/init.h>
  14 #include <linux/slab.h>
  15 #include <linux/tty.h>
  16 #include <linux/module.h>
  17 #include <linux/usb.h>
  18 #include <linux/usb/serial.h>
  19
  20 /* EZ-USB Control and Status Register.  Bit 0 controls 8051 reset */
  21 #define CPUCS_REG    0x7F92
  22
  23 int ezusb_writememory(struct usb_serial *serial, int address,
  24                                 unsigned char *data, int length, __u8 request)
  25 {
  26         int result;
  27         unsigned char *transfer_buffer;
  28
  29         /* dbg("ezusb_writememory %x, %d", address, length); */
  30         if (!serial->dev) {
  31                 printk(KERN_ERR "ezusb: %s - no physical device present, "
  32                        "failing.\n", __func__);
  33                 return -ENODEV;
  34         }
  35
  36         transfer_buffer = kmemdup(data, length, GFP_KERNEL);
  37         if (!transfer_buffer) {
  38                 dev_err(&serial->dev->dev, "%s - kmalloc(%d) failed.\n",
  39                                                         __func__, length);
  40                 return -ENOMEM;
  41         }
  42         result = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
  43                      request, 0x40, address, 0, transfer_buffer, length, 3000);
  44         kfree(transfer_buffer);
  45         return result;
  46 }
  47 EXPORT_SYMBOL_GPL(ezusb_writememory);
  48
  49 int ezusb_set_reset(struct usb_serial *serial, unsigned char reset_bit)
  50 {
  51         int response;
  52
  53         /* dbg("%s - %d", __func__, reset_bit); */
  54         response = ezusb_writememory(serial, CPUCS_REG, &reset_bit, 1, 0xa0);
  55         if (response < 0)
  56                 dev_err(&serial->dev->dev, "%s- %d failed\n",
  57                                                 __func__, reset_bit);
  58         return response;
  59 }
  60 EXPORT_SYMBOL_GPL(ezusb_set_reset);
  61