linux-imx

/*

 * parport-to-butterfly adapter

 *

 * Copyright (C) 2005 David Brownell

 *

 * 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.

 */

#include <linux/kernel.h>

#include <linux/init.h>

#include <linux/delay.h>

#include <linux/module.h>

#include <linux/device.h>

#include <linux/parport.h>

​

#include <linux/sched.h>

#include <linux/spi/spi.h>

#include <linux/spi/spi_bitbang.h>

#include <linux/spi/flash.h>

​

#include <linux/mtd/partitions.h>

​

/*

 * This uses SPI to talk with an "AVR Butterfly", which is a $US20 card

 * with a battery powered AVR microcontroller and lots of goodies.  You

 * can use GCC to develop firmware for this.

 *

 * See Documentation/spi/butterfly for information about how to build

 * and use this custom parallel port cable.

 */

​

/* DATA output bits (pins 2..9 == D0..D7) */

#define butterfly_nreset (1 << 1)       /* pin 3 */

​

#define spi_sck_bit (1 << 0)        /* pin 2 */

#define spi_mosi_bit    (1 << 7)        /* pin 9 */

​

#define vcc_bits    ((1 << 6) | (1 << 5))   /* pins 7, 8 */

​

/* STATUS input bits */

#define spi_miso_bit    PARPORT_STATUS_BUSY /* pin 11 */

​

/* CONTROL output bits */

#define spi_cs_bit  PARPORT_CONTROL_SELECT  /* pin 17 */

​

static inline struct butterfly *spidev_to_pp(struct spi_device *spi)

{

    return spi->controller_data;

}

​

struct butterfly {

    /* REVISIT ... for now, this must be first */

    struct spi_bitbang  bitbang;

​

    struct parport      *port;

    struct pardevice    *pd;

​

    u8          lastbyte;

​

    struct spi_device   *dataflash;

    struct spi_device   *butterfly;

    struct spi_board_info   info[2];

​

};

​

/*----------------------------------------------------------------------*/

​

static inline void

setsck(struct spi_device *spi, int is_on)

{

    struct butterfly    *pp = spidev_to_pp(spi);

    u8          bit, byte = pp->lastbyte;

​

    bit = spi_sck_bit;

​

    if (is_on)

        byte |= bit;

    else

        byte &= ~bit;

    parport_write_data(pp->port, byte);

    pp->lastbyte = byte;

}

​

static inline void

setmosi(struct spi_device *spi, int is_on)