/*********************************************************************
   *                
   * Filename:      tekram.c
   * Version:       1.3
   * Description:   Implementation of the Tekram IrMate IR-210B dongle
   * Status:        Experimental.
   * Author:        Dag Brattli <dagb@cs.uit.no>
   * Created at:    Wed Oct 21 20:02:35 1998
   * Modified at:   Sun Oct 27 22:02:38 2002
   * Modified by:   Martin Diehl <mad@mdiehl.de>
   * 
   *     Copyright (c) 1998-1999 Dag Brattli,
   *     Copyright (c) 2002 Martin Diehl,
   *     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 tekram_delay = 150;		/* default is 150 ms */
  module_param(tekram_delay, int, 0);
  MODULE_PARM_DESC(tekram_delay, "tekram dongle write complete delay");
  
  static int tekram_open(struct sir_dev *);
  static int tekram_close(struct sir_dev *);
  static int tekram_change_speed(struct sir_dev *, unsigned);
  static int tekram_reset(struct sir_dev *);
  
  #define TEKRAM_115200 0x00
  #define TEKRAM_57600  0x01
  #define TEKRAM_38400  0x02
  #define TEKRAM_19200  0x03
  #define TEKRAM_9600   0x04
  
  #define TEKRAM_PW     0x10 /* Pulse select bit */
  
  static struct dongle_driver tekram = {
  	.owner		= THIS_MODULE,
  	.driver_name	= "Tekram IR-210B",
  	.type		= IRDA_TEKRAM_DONGLE,
  	.open		= tekram_open,
  	.close		= tekram_close,
  	.reset		= tekram_reset,
  	.set_speed	= tekram_change_speed,
  };
  
  static int __init tekram_sir_init(void)
  {
  	if (tekram_delay < 1  ||  tekram_delay > 500)
  		tekram_delay = 200;
  	IRDA_DEBUG(1, "%s - using %d ms delay
  ",
  		tekram.driver_name, tekram_delay);
  	return irda_register_dongle(&tekram);
  }
  
  static void __exit tekram_sir_cleanup(void)
  {
  	irda_unregister_dongle(&tekram);
  }
  
  static int tekram_open(struct sir_dev *dev)
  {
  	struct qos_info *qos = &dev->qos;
  
  	IRDA_DEBUG(2, "%s()
  ", __func__);
  
  	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 = 0x01; /* Needs at least 10 ms */	
  	irda_qos_bits_to_value(qos);
  
  	/* irda thread waits 50 msec for power settling */
  
  	return 0;
  }
  
  static int tekram_close(struct sir_dev *dev)
  {
  	IRDA_DEBUG(2, "%s()
  ", __func__);
  
  	/* Power off dongle */
  	sirdev_set_dtr_rts(dev, FALSE, FALSE);
  
  	return 0;
  }
  
  /*
   * Function tekram_change_speed (dev, state, speed)
   *
   *    Set the speed for the Tekram IRMate 210 type dongle. Warning, this 
   *    function must be called with a process context!
   *
   *    Algorithm
   *    1. clear DTR 
   *    2. set RTS, and wait at least 7 us
   *    3. send Control Byte to the IR-210 through TXD to set new baud rate
   *       wait until the stop bit of Control Byte is sent (for 9600 baud rate, 
   *       it takes about 100 msec)
   *
   *	[oops, why 100 msec? sending 1 byte (10 bits) takes 1.05 msec
   *	 - is this probably to compensate for delays in tty layer?]
   *
   *    5. clear RTS (return to NORMAL Operation)
   *    6. wait at least 50 us, new setting (baud rate, etc) takes effect here 
   *       after
   */
  
  #define TEKRAM_STATE_WAIT_SPEED	(SIRDEV_STATE_DONGLE_SPEED + 1)
  
  static int tekram_change_speed(struct sir_dev *dev, unsigned speed)
  {
  	unsigned state = dev->fsm.substate;
  	unsigned delay = 0;
  	u8 byte;
  	static int ret = 0;
  	
  	IRDA_DEBUG(2, "%s()
  ", __func__);
  
  	switch(state) {
  	case SIRDEV_STATE_DONGLE_SPEED:
  
  		switch (speed) {
  		default:
  			speed = 9600;
  			ret = -EINVAL;
  			/* fall thru */
  		case 9600:
  			byte = TEKRAM_PW|TEKRAM_9600;
  			break;
  		case 19200:
  			byte = TEKRAM_PW|TEKRAM_19200;
  			break;
  		case 38400:
  			byte = TEKRAM_PW|TEKRAM_38400;
  			break;
  		case 57600:
  			byte = TEKRAM_PW|TEKRAM_57600;
  			break;
  		case 115200:
  			byte = TEKRAM_115200;
  			break;
  		}
  
  		/* Set DTR, Clear RTS */
  		sirdev_set_dtr_rts(dev, TRUE, FALSE);
  	
  		/* Wait at least 7us */
  		udelay(14);
  
  		/* Write control byte */
  		sirdev_raw_write(dev, &byte, 1);
  		
  		dev->speed = speed;
  
  		state = TEKRAM_STATE_WAIT_SPEED;
  		delay = tekram_delay;
  		break;
  
  	case TEKRAM_STATE_WAIT_SPEED:
  		/* Set DTR, Set RTS */
  		sirdev_set_dtr_rts(dev, TRUE, TRUE);
  		udelay(50);
  		break;
  
  	default:
  		IRDA_ERROR("%s - undefined state %d
  ", __func__, state);
  		ret = -EINVAL;
  		break;
  	}
  
  	dev->fsm.substate = state;
  	return (delay > 0) ? delay : ret;
  }
  
  /*
   * Function tekram_reset (driver)
   *
   *      This function resets the tekram dongle. Warning, this function 
   *      must be called with a process context!! 
   *
   *      Algorithm:
   *    	  0. Clear RTS and DTR, and wait 50 ms (power off the IR-210 )
   *        1. clear RTS 
   *        2. set DTR, and wait at least 1 ms 
   *        3. clear DTR to SPACE state, wait at least 50 us for further 
   *         operation
   */
  
  static int tekram_reset(struct sir_dev *dev)
  {
  	IRDA_DEBUG(2, "%s()
  ", __func__);
  
  	/* Clear DTR, Set RTS */
  	sirdev_set_dtr_rts(dev, FALSE, TRUE); 
  
  	/* Should sleep 1 ms */
  	msleep(1);
  
  	/* Set DTR, Set RTS */
  	sirdev_set_dtr_rts(dev, TRUE, TRUE);
  	
  	/* Wait at least 50 us */
  	udelay(75);
  
  	dev->speed = 9600;
  
  	return 0;
  }
  
  MODULE_AUTHOR("Dag Brattli <dagb@cs.uit.no>");
  MODULE_DESCRIPTION("Tekram IrMate IR-210B dongle driver");
  MODULE_LICENSE("GPL");
  MODULE_ALIAS("irda-dongle-0"); /* IRDA_TEKRAM_DONGLE */
  		
  module_init(tekram_sir_init);
  module_exit(tekram_sir_cleanup);