girbil-sir.c

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/*********************************************************************
 *
 * Filename:      girbil.c
 * Version:       1.2
 * Description:   Implementation for the Greenwich GIrBIL dongle
 * Status:        Experimental.
 * Author:        Dag Brattli <[email protected]>
 * Created at:    Sat Feb  6 21:02:33 1999
 * Modified at:   Fri Dec 17 09:13:20 1999
 * Modified by:   Dag Brattli <[email protected]>
 *
 *     Copyright (c) 1999 Dag Brattli, All Rights Reserved.
 *     
 *     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.
 * 
 *     Neither Dag Brattli nor University of Tromsø admit liability nor
 *     provide warranty for any of this software. This material is
 *     provided "AS-IS" and at no charge.
 *
 ********************************************************************/

#include <linux/module.h>
#include <linux/delay.h>
#include <linux/init.h>

#include <net/irda/irda.h>

#include "sir-dev.h"

static int girbil_reset(struct sir_dev *dev);
static int girbil_open(struct sir_dev *dev);
static int girbil_close(struct sir_dev *dev);
static int girbil_change_speed(struct sir_dev *dev, unsigned speed);

/* Control register 1 */
#define GIRBIL_TXEN    0x01 /* Enable transmitter */
#define GIRBIL_RXEN    0x02 /* Enable receiver */
#define GIRBIL_ECAN    0x04 /* Cancel self emitted data */
#define GIRBIL_ECHO    0x08 /* Echo control characters */

/* LED Current Register (0x2) */
#define GIRBIL_HIGH    0x20
#define GIRBIL_MEDIUM  0x21
#define GIRBIL_LOW     0x22

/* Baud register (0x3) */
#define GIRBIL_2400    0x30
#define GIRBIL_4800    0x31
#define GIRBIL_9600    0x32
#define GIRBIL_19200   0x33
#define GIRBIL_38400   0x34
#define GIRBIL_57600   0x35
#define GIRBIL_115200  0x36

/* Mode register (0x4) */
#define GIRBIL_IRDA    0x40
#define GIRBIL_ASK     0x41

/* Control register 2 (0x5) */
#define GIRBIL_LOAD    0x51 /* Load the new baud rate value */

static struct dongle_driver girbil = {
    .owner      = THIS_MODULE,
    .driver_name    = "Greenwich GIrBIL",
    .type       = IRDA_GIRBIL_DONGLE,
    .open       = girbil_open,
    .close      = girbil_close,
    .reset      = girbil_reset,
    .set_speed  = girbil_change_speed,
};

static int __init girbil_sir_init(void)
{
    return irda_register_dongle(&girbil);
}

static void __exit girbil_sir_cleanup(void)
{
    irda_unregister_dongle(&girbil);
}

static int girbil_open(struct sir_dev *dev)
{
    struct qos_info *qos = &dev->qos;

    IRDA_DEBUG(2, "%s()\n", __func__);

    /* Power on dongle */
    sirdev_set_dtr_rts(dev, TRUE, TRUE);

    qos->baud_rate.bits &= IR_9600|IR_19200|IR_38400|IR_57600|IR_115200;
    qos->min_turn_time.bits = 0x03;
    irda_qos_bits_to_value(qos);

    /* irda thread waits 50 msec for power settling */

    return 0;
}

static int girbil_close(struct sir_dev *dev)
{
    IRDA_DEBUG(2, "%s()\n", __func__);

    /* Power off dongle */
    sirdev_set_dtr_rts(dev, FALSE, FALSE);

    return 0;
}

/*
 * Function girbil_change_speed (dev, speed)
 *
 *    Set the speed for the Girbil type dongle.
 *
 */

#define GIRBIL_STATE_WAIT_SPEED (SIRDEV_STATE_DONGLE_SPEED + 1)

static int girbil_change_speed(struct sir_dev *dev, unsigned speed)
{
    unsigned state = dev->fsm.substate;
    unsigned delay = 0;
    u8 control[2];
    static int ret = 0;

    IRDA_DEBUG(2, "%s()\n", __func__);

    /* dongle alread reset - port and dongle at default speed */

    switch(state) {

    case SIRDEV_STATE_DONGLE_SPEED:

        /* Set DTR and Clear RTS to enter command mode */
        sirdev_set_dtr_rts(dev, FALSE, TRUE);

        udelay(25);     /* better wait a little while */

        ret = 0;
        switch (speed) {
        default:
            ret = -EINVAL;
            /* fall through */
        case 9600:
            control[0] = GIRBIL_9600;
            break;
        case 19200:
            control[0] = GIRBIL_19200;
            break;
        case 34800:
            control[0] = GIRBIL_38400;
            break;
        case 57600:
            control[0] = GIRBIL_57600;
            break;
        case 115200:
            control[0] = GIRBIL_115200;
            break;
        }
        control[1] = GIRBIL_LOAD;
    
        /* Write control bytes */
        sirdev_raw_write(dev, control, 2);

        dev->speed = speed;

        state = GIRBIL_STATE_WAIT_SPEED;
        delay = 100;
        break;

    case GIRBIL_STATE_WAIT_SPEED:
        /* Go back to normal mode */
        sirdev_set_dtr_rts(dev, TRUE, TRUE);

        udelay(25);     /* better wait a little while */
        break;

    default:
        IRDA_ERROR("%s - undefined state %d\n", __func__, state);
        ret = -EINVAL;
        break;
    }
    dev->fsm.substate = state;
    return (delay > 0) ? delay : ret;
}

/*
 * Function girbil_reset (driver)
 *
 *      This function resets the girbil dongle.
 *
 *      Algorithm:
 *        0. set RTS, and wait at least 5 ms
 *        1. clear RTS
 */


#define GIRBIL_STATE_WAIT1_RESET    (SIRDEV_STATE_DONGLE_RESET + 1)
#define GIRBIL_STATE_WAIT2_RESET    (SIRDEV_STATE_DONGLE_RESET + 2)
#define GIRBIL_STATE_WAIT3_RESET    (SIRDEV_STATE_DONGLE_RESET + 3)

static int girbil_reset(struct sir_dev *dev)
{
    unsigned state = dev->fsm.substate;
    unsigned delay = 0;
    u8 control = GIRBIL_TXEN | GIRBIL_RXEN;
    int ret = 0;

    IRDA_DEBUG(2, "%s()\n", __func__);

    switch (state) {
    case SIRDEV_STATE_DONGLE_RESET:
        /* Reset dongle */
        sirdev_set_dtr_rts(dev, TRUE, FALSE);
        /* Sleep at least 5 ms */
        delay = 20;
        state = GIRBIL_STATE_WAIT1_RESET;
        break;

    case GIRBIL_STATE_WAIT1_RESET:
        /* Set DTR and clear RTS to enter command mode */
        sirdev_set_dtr_rts(dev, FALSE, TRUE);
        delay = 20;
        state = GIRBIL_STATE_WAIT2_RESET;
        break;

    case GIRBIL_STATE_WAIT2_RESET:
        /* Write control byte */
        sirdev_raw_write(dev, &control, 1);
        delay = 20;
        state = GIRBIL_STATE_WAIT3_RESET;
        break;

    case GIRBIL_STATE_WAIT3_RESET:
        /* Go back to normal mode */
        sirdev_set_dtr_rts(dev, TRUE, TRUE);
        dev->speed = 9600;
        break;

    default:
        IRDA_ERROR("%s(), undefined state %d\n", __func__, state);
        ret = -1;
        break;
    }
    dev->fsm.substate = state;
    return (delay > 0) ? delay : ret;
}

MODULE_AUTHOR("Dag Brattli <[email protected]>");
MODULE_DESCRIPTION("Greenwich GIrBIL dongle driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("irda-dongle-4"); /* IRDA_GIRBIL_DONGLE */

module_init(girbil_sir_init);
module_exit(girbil_sir_cleanup);