root/drivers/misc/altera-stapl/altera-lpt.c

DEFINITIONS

1. byteblaster_write
2. byteblaster_read
3. netup_jtag_io_lpt

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * altera-lpt.c
   4  *
   5  * altera FPGA driver
   6  *
   7  * Copyright (C) Altera Corporation 1998-2001
   8  * Copyright (C) 2010 NetUP Inc.
   9  * Copyright (C) 2010 Abylay Ospan <aospan@netup.ru>
  10  */
  11 
  12 #include <linux/io.h>
  13 #include <linux/kernel.h>
  14 #include "altera-exprt.h"
  15 
  16 static int lpt_hardware_initialized;
  17 
  18 static void byteblaster_write(int port, int data)
  19 {
  20         outb((u8)data, (u16)(port + 0x378));
  21 };
  22 
  23 static int byteblaster_read(int port)
  24 {
  25         int data = 0;
  26         data = inb((u16)(port + 0x378));
  27         return data & 0xff;
  28 };
  29 
  30 int netup_jtag_io_lpt(void *device, int tms, int tdi, int read_tdo)
  31 {
  32         int data = 0;
  33         int tdo = 0;
  34         int initial_lpt_ctrl = 0;
  35 
  36         if (!lpt_hardware_initialized) {
  37                 initial_lpt_ctrl = byteblaster_read(2);
  38                 byteblaster_write(2, (initial_lpt_ctrl | 0x02) & 0xdf);
  39                 lpt_hardware_initialized = 1;
  40         }
  41 
  42         data = ((tdi ? 0x40 : 0) | (tms ? 0x02 : 0));
  43 
  44         byteblaster_write(0, data);
  45 
  46         if (read_tdo) {
  47                 tdo = byteblaster_read(1);
  48                 tdo = ((tdo & 0x80) ? 0 : 1);
  49         }
  50 
  51         byteblaster_write(0, data | 0x01);
  52 
  53         byteblaster_write(0, data);
  54 
  55         return tdo;
  56 }