/*********************************************************************
 *
 * Filename:      girbil.c
 * Version:       1.2
 * Description:   Implementation for the Greenwich GIrBIL dongle
 * Status:        Experimental.
 * Author:        Dag Brattli <dagb@cs.uit.no>
 * Created at:    Sat Feb  6 21:02:33 1999
 * Modified at:   Fri Dec 17 09:13:20 1999
 * Modified by:   Dag Brattli <dagb@cs.uit.no>
 *
 *     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 <dagb@cs.uit.no>");
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);