linux/drivers/net/irda/litelink-sir.c
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   1/*********************************************************************
   2 *                
   3 * Filename:      litelink.c
   4 * Version:       1.1
   5 * Description:   Driver for the Parallax LiteLink dongle
   6 * Status:        Stable
   7 * Author:        Dag Brattli <dagb@cs.uit.no>
   8 * Created at:    Fri May  7 12:50:33 1999
   9 * Modified at:   Fri Dec 17 09:14:23 1999
  10 * Modified by:   Dag Brattli <dagb@cs.uit.no>
  11 * 
  12 *     Copyright (c) 1999 Dag Brattli, All Rights Reserved.
  13 *     
  14 *     This program is free software; you can redistribute it and/or 
  15 *     modify it under the terms of the GNU General Public License as 
  16 *     published by the Free Software Foundation; either version 2 of 
  17 *     the License, or (at your option) any later version.
  18 * 
  19 *     This program is distributed in the hope that it will be useful,
  20 *     but WITHOUT ANY WARRANTY; without even the implied warranty of
  21 *     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  22 *     GNU General Public License for more details.
  23 * 
  24 *     You should have received a copy of the GNU General Public License 
  25 *     along with this program; if not, write to the Free Software 
  26 *     Foundation, Inc., 59 Temple Place, Suite 330, Boston, 
  27 *     MA 02111-1307 USA
  28 *     
  29 ********************************************************************/
  30
  31/*
  32 * Modified at:   Thu Jan 15 2003
  33 * Modified by:   Eugene Crosser <crosser@average.org>
  34 *
  35 * Convert to "new" IRDA infrastructure for kernel 2.6
  36 */
  37
  38#include <linux/module.h>
  39#include <linux/delay.h>
  40#include <linux/init.h>
  41
  42#include <net/irda/irda.h>
  43
  44#include "sir-dev.h"
  45
  46#define MIN_DELAY 25      /* 15 us, but wait a little more to be sure */
  47#define MAX_DELAY 10000   /* 1 ms */
  48
  49static int litelink_open(struct sir_dev *dev);
  50static int litelink_close(struct sir_dev *dev);
  51static int litelink_change_speed(struct sir_dev *dev, unsigned speed);
  52static int litelink_reset(struct sir_dev *dev);
  53
  54/* These are the baudrates supported - 9600 must be last one! */
  55static unsigned baud_rates[] = { 115200, 57600, 38400, 19200, 9600 };
  56
  57static struct dongle_driver litelink = {
  58        .owner          = THIS_MODULE,
  59        .driver_name    = "Parallax LiteLink",
  60        .type           = IRDA_LITELINK_DONGLE,
  61        .open           = litelink_open,
  62        .close          = litelink_close,
  63        .reset          = litelink_reset,
  64        .set_speed      = litelink_change_speed,
  65};
  66
  67static int __init litelink_sir_init(void)
  68{
  69        return irda_register_dongle(&litelink);
  70}
  71
  72static void __exit litelink_sir_cleanup(void)
  73{
  74        irda_unregister_dongle(&litelink);
  75}
  76
  77static int litelink_open(struct sir_dev *dev)
  78{
  79        struct qos_info *qos = &dev->qos;
  80
  81        IRDA_DEBUG(2, "%s()\n", __func__);
  82
  83        /* Power up dongle */
  84        sirdev_set_dtr_rts(dev, TRUE, TRUE);
  85
  86        /* Set the speeds we can accept */
  87        qos->baud_rate.bits &= IR_115200|IR_57600|IR_38400|IR_19200|IR_9600;
  88        qos->min_turn_time.bits = 0x7f; /* Needs 0.01 ms */
  89        irda_qos_bits_to_value(qos);
  90
  91        /* irda thread waits 50 msec for power settling */
  92
  93        return 0;
  94}
  95
  96static int litelink_close(struct sir_dev *dev)
  97{
  98        IRDA_DEBUG(2, "%s()\n", __func__);
  99
 100        /* Power off dongle */
 101        sirdev_set_dtr_rts(dev, FALSE, FALSE);
 102
 103        return 0;
 104}
 105
 106/*
 107 * Function litelink_change_speed (task)
 108 *
 109 *    Change speed of the Litelink dongle. To cycle through the available 
 110 *    baud rates, pulse RTS low for a few ms.  
 111 */
 112static int litelink_change_speed(struct sir_dev *dev, unsigned speed)
 113{
 114        int i;
 115
 116        IRDA_DEBUG(2, "%s()\n", __func__);
 117
 118        /* dongle already reset by irda-thread - current speed (dongle and
 119         * port) is the default speed (115200 for litelink!)
 120         */
 121
 122        /* Cycle through avaiable baudrates until we reach the correct one */
 123        for (i = 0; baud_rates[i] != speed; i++) {
 124
 125                /* end-of-list reached due to invalid speed request */
 126                if (baud_rates[i] == 9600)
 127                        break;
 128
 129                /* Set DTR, clear RTS */
 130                sirdev_set_dtr_rts(dev, FALSE, TRUE);
 131
 132                /* Sleep a minimum of 15 us */
 133                udelay(MIN_DELAY);
 134
 135                /* Set DTR, Set RTS */
 136                sirdev_set_dtr_rts(dev, TRUE, TRUE);
 137
 138                /* Sleep a minimum of 15 us */
 139                udelay(MIN_DELAY);
 140        }
 141
 142        dev->speed = baud_rates[i];
 143
 144        /* invalid baudrate should not happen - but if, we return -EINVAL and
 145         * the dongle configured for 9600 so the stack has a chance to recover
 146         */
 147
 148        return (dev->speed == speed) ? 0 : -EINVAL;
 149}
 150
 151/*
 152 * Function litelink_reset (task)
 153 *
 154 *      Reset the Litelink type dongle.
 155 *
 156 */
 157static int litelink_reset(struct sir_dev *dev)
 158{
 159        IRDA_DEBUG(2, "%s()\n", __func__);
 160
 161        /* probably the power-up can be dropped here, but with only
 162         * 15 usec delay it's not worth the risk unless somebody with
 163         * the hardware confirms it doesn't break anything...
 164         */
 165
 166        /* Power on dongle */
 167        sirdev_set_dtr_rts(dev, TRUE, TRUE);
 168
 169        /* Sleep a minimum of 15 us */
 170        udelay(MIN_DELAY);
 171
 172        /* Clear RTS to reset dongle */
 173        sirdev_set_dtr_rts(dev, TRUE, FALSE);
 174
 175        /* Sleep a minimum of 15 us */
 176        udelay(MIN_DELAY);
 177
 178        /* Go back to normal mode */
 179        sirdev_set_dtr_rts(dev, TRUE, TRUE);
 180
 181        /* Sleep a minimum of 15 us */
 182        udelay(MIN_DELAY);
 183
 184        /* This dongles speed defaults to 115200 bps */
 185        dev->speed = 115200;
 186
 187        return 0;
 188}
 189
 190MODULE_AUTHOR("Dag Brattli <dagb@cs.uit.no>");
 191MODULE_DESCRIPTION("Parallax Litelink dongle driver");  
 192MODULE_LICENSE("GPL");
 193MODULE_ALIAS("irda-dongle-5"); /* IRDA_LITELINK_DONGLE */
 194
 195/*
 196 * Function init_module (void)
 197 *
 198 *    Initialize Litelink module
 199 *
 200 */
 201module_init(litelink_sir_init);
 202
 203/*
 204 * Function cleanup_module (void)
 205 *
 206 *    Cleanup Litelink module
 207 *
 208 */
 209module_exit(litelink_sir_cleanup);
 210