/*
  tspi_4fx.c
  David Rowe 30 August 2006
 
  Linux device driver for Blackfin that implements unit tests for the
  4fx daughter board.  Tested on a Blackfin BF533 STAMP with a 4fx 
  daughter board attached.

  See below for running instructions.  See also the hardware-x.y tarball
  cpld/README to explain how the CPLD works on the 4fx board.
*/

/*
  Copyright (C) 2006 David Rowe
 
  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 program is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.
  
  You should have received a copy of the GNU General Public License
  along with this program; if not, write to the Free Software
  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 
*/

#include <linux/module.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/interrupt.h>
#include <linux/sched.h>
#include <asm/uaccess.h>
#include <asm/io.h>
#include <asm/bfin5xx_spi.h>
#include <linux/delay.h>
#include <bfsi.h>

/* 
   Need to do include bfsi module this way due to kbuild restrictions.
   I would rather have it as seperately compiled module but I
   couldn't work out how to specify the path I wanted
*/
#include "../../src/bfsi.c" 

#define NCS_A 3
#define NCS_B 2
#define TESTS       100

/*----------------------- TEST PARAMETERS -----------------------------*/

static int baud    = 4; /* gives max for sys clock = 100 MHz for Si3050 */
static int tests   = 1;
static int select  = 5; /* LED register */ 
static int data    = 1; /* LED1 = red   */

/*------------------------MODULE INIT FUNCTION --------------------------*/

/* 
   The test can be controlled by command line parameters when the module
   is installed.  The test runs by simply installing the module using insmod,
   to run again rmmod the module and insmod again.  For example:

   1/ Make LED1 light red.

     root:~> insmod tspi.ko

   2/ Make LED1 light green.

     root:~> insmod tspi.ko data=0x2

   3/ Send the value 0x55 100 times to the SPI device on nCS3:

     root:~> insmod tspi.ko tests=100 select=0x3 data=0x2

   4/ Make all LEDs red:

     root:~> insmod tspi.ko data=0x55

   5/ Make all LEDs green:

     root:~> insmod tspi.ko data=0xaa

   5/ Make all LEDs RGRG:

     root:~> insmod tspi.ko data=0x66

   Notes: 

   + All these examples assume the 4fx board "address" as set by 
   JMP10 & JMP11 is 00 (no shorting links on jumpers).

   + Using baud=0xffff is useful to slow down tests so you can see
   continous signals for a while (especially if you don'thave a storage 
   scope :-) )
*/

static int __init tspi_4fx_init_module (void) {
  int i;

  printk("initializing module\n");
		
  bfsi_spi_init(baud, (1<<NCS_A) | (1<<NCS_B));

  for(i=0; i<tests; i++) {
    bfsi_spi_write_8_bits(NCS_B, select);
    bfsi_spi_write_8_bits(NCS_A, data); 
  }

  return 0;
}

/*------------------------ MODULE CLEANUP FUNCTION -----------------------*/

static void __exit tspi_4fx_cleanup_module (void) {
	printk("cleaning up module\n");
}

module_init(tspi_4fx_init_module);
module_exit(tspi_4fx_cleanup_module);

MODULE_AUTHOR("David Rowe");
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Blackfin/4fx SPI Unit Test");

module_param(baud, int, 0600);
module_param(tests, int, 0600);
module_param(select, int, 0600);
module_param(data, int, 0600);