drivers/net/irda/tekram-sir.c

   1 /*********************************************************************
   2  *
   3  * Filename:      tekram.c
   4  * Version:       1.3
   5  * Description:   Implementation of the Tekram IrMate IR-210B dongle
   6  * Status:        Experimental.
   7  * Author:        Dag Brattli <dagb@cs.uit.no>
   8  * Created at:    Wed Oct 21 20:02:35 1998
   9  * Modified at:   Sun Oct 27 22:02:38 2002
  10  * Modified by:   Martin Diehl <mad@mdiehl.de>
  11  *
  12  *     Copyright (c) 1998-1999 Dag Brattli,
  13  *     Copyright (c) 2002 Martin Diehl,
  14  *     All Rights Reserved.
  15  *
  16  *     This program is free software; you can redistribute it and/or
  17  *     modify it under the terms of the GNU General Public License as
  18  *     published by the Free Software Foundation; either version 2 of
  19  *     the License, or (at your option) any later version.
  20  *
  21  *     Neither Dag Brattli nor University of Tromsø admit liability nor
  22  *     provide warranty for any of this software. This material is
  23  *     provided "AS-IS" and at no charge.
  24  *
  25  ********************************************************************/
  26
  27 #include <linux/module.h>
  28 #include <linux/delay.h>
  29 #include <linux/init.h>
  30
  31 #include <net/irda/irda.h>
  32
  33 #include "sir-dev.h"
  34
  35 static int tekram_delay = 150;          /* default is 150 ms */
  36 module_param(tekram_delay, int, 0);
  37 MODULE_PARM_DESC(tekram_delay, "tekram dongle write complete delay");
  38
  39 static int tekram_open(struct sir_dev *);
  40 static int tekram_close(struct sir_dev *);
  41 static int tekram_change_speed(struct sir_dev *, unsigned);
  42 static int tekram_reset(struct sir_dev *);
  43
  44 #define TEKRAM_115200 0x00
  45 #define TEKRAM_57600  0x01
  46 #define TEKRAM_38400  0x02
  47 #define TEKRAM_19200  0x03
  48 #define TEKRAM_9600   0x04
  49
  50 #define TEKRAM_PW     0x10 /* Pulse select bit */
  51
  52 static struct dongle_driver tekram = {
  53         .owner          = THIS_MODULE,
  54         .driver_name    = "Tekram IR-210B",
  55         .type           = IRDA_TEKRAM_DONGLE,
  56         .open           = tekram_open,
  57         .close          = tekram_close,
  58         .reset          = tekram_reset,
  59         .set_speed      = tekram_change_speed,
  60 };
  61
  62 static int __init tekram_sir_init(void)
  63 {
  64         if (tekram_delay < 1  ||  tekram_delay > 500)
  65                 tekram_delay = 200;
  66         IRDA_DEBUG(1, "%s - using %d ms delay\n",
  67                 tekram.driver_name, tekram_delay);
  68         return irda_register_dongle(&tekram);
  69 }
  70
  71 static void __exit tekram_sir_cleanup(void)
  72 {
  73         irda_unregister_dongle(&tekram);
  74 }
  75
  76 static int tekram_open(struct sir_dev *dev)
  77 {
  78         struct qos_info *qos = &dev->qos;
  79
  80         IRDA_DEBUG(2, "%s()\n", __FUNCTION__);
  81
  82         sirdev_set_dtr_rts(dev, TRUE, TRUE);
  83
  84         qos->baud_rate.bits &= IR_9600|IR_19200|IR_38400|IR_57600|IR_115200;
  85         qos->min_turn_time.bits = 0x01; /* Needs at least 10 ms */
  86         irda_qos_bits_to_value(qos);
  87
  88         /* irda thread waits 50 msec for power settling */
  89
  90         return 0;
  91 }
  92
  93 static int tekram_close(struct sir_dev *dev)
  94 {
  95         IRDA_DEBUG(2, "%s()\n", __FUNCTION__);
  96
  97         /* Power off dongle */
  98         sirdev_set_dtr_rts(dev, FALSE, FALSE);
  99
 100         return 0;
 101 }
 102
 103 /*
 104  * Function tekram_change_speed (dev, state, speed)
 105  *
 106  *    Set the speed for the Tekram IRMate 210 type dongle. Warning, this
 107  *    function must be called with a process context!
 108  *
 109  *    Algorithm
 110  *    1. clear DTR
 111  *    2. set RTS, and wait at least 7 us
 112  *    3. send Control Byte to the IR-210 through TXD to set new baud rate
 113  *       wait until the stop bit of Control Byte is sent (for 9600 baud rate,
 114  *       it takes about 100 msec)
 115  *
 116  *      [oops, why 100 msec? sending 1 byte (10 bits) takes 1.05 msec
 117  *       - is this probably to compensate for delays in tty layer?]
 118  *
 119  *    5. clear RTS (return to NORMAL Operation)
 120  *    6. wait at least 50 us, new setting (baud rate, etc) takes effect here
 121  *       after
 122  */
 123
 124 #define TEKRAM_STATE_WAIT_SPEED (SIRDEV_STATE_DONGLE_SPEED + 1)
 125
 126 static int tekram_change_speed(struct sir_dev *dev, unsigned speed)
 127 {
 128         unsigned state = dev->fsm.substate;
 129         unsigned delay = 0;
 130         u8 byte;
 131         static int ret = 0;
 132
 133         IRDA_DEBUG(2, "%s()\n", __FUNCTION__);
 134
 135         switch(state) {
 136         case SIRDEV_STATE_DONGLE_SPEED:
 137
 138                 switch (speed) {
 139                 default:
 140                         speed = 9600;
 141                         ret = -EINVAL;
 142                         /* fall thru */
 143                 case 9600:
 144                         byte = TEKRAM_PW|TEKRAM_9600;
 145                         break;
 146                 case 19200:
 147                         byte = TEKRAM_PW|TEKRAM_19200;
 148                         break;
 149                 case 38400:
 150                         byte = TEKRAM_PW|TEKRAM_38400;
 151                         break;
 152                 case 57600:
 153                         byte = TEKRAM_PW|TEKRAM_57600;
 154                         break;
 155                 case 115200:
 156                         byte = TEKRAM_115200;
 157                         break;
 158                 }
 159
 160                 /* Set DTR, Clear RTS */
 161                 sirdev_set_dtr_rts(dev, TRUE, FALSE);
 162
 163                 /* Wait at least 7us */
 164                 udelay(14);
 165
 166                 /* Write control byte */
 167                 sirdev_raw_write(dev, &byte, 1);
 168
 169                 dev->speed = speed;
 170
 171                 state = TEKRAM_STATE_WAIT_SPEED;
 172                 delay = tekram_delay;
 173                 break;
 174
 175         case TEKRAM_STATE_WAIT_SPEED:
 176                 /* Set DTR, Set RTS */
 177                 sirdev_set_dtr_rts(dev, TRUE, TRUE);
 178                 udelay(50);
 179                 break;
 180
 181         default:
 182                 IRDA_ERROR("%s - undefined state %d\n", __FUNCTION__, state);
 183                 ret = -EINVAL;
 184                 break;
 185         }
 186
 187         dev->fsm.substate = state;
 188         return (delay > 0) ? delay : ret;
 189 }
 190
 191 /*
 192  * Function tekram_reset (driver)
 193  *
 194  *      This function resets the tekram dongle. Warning, this function
 195  *      must be called with a process context!!
 196  *
 197  *      Algorithm:
 198  *        0. Clear RTS and DTR, and wait 50 ms (power off the IR-210 )
 199  *        1. clear RTS
 200  *        2. set DTR, and wait at least 1 ms
 201  *        3. clear DTR to SPACE state, wait at least 50 us for further
 202  *         operation
 203  */
 204
 205 static int tekram_reset(struct sir_dev *dev)
 206 {
 207         IRDA_DEBUG(2, "%s()\n", __FUNCTION__);
 208
 209         /* Clear DTR, Set RTS */
 210         sirdev_set_dtr_rts(dev, FALSE, TRUE);
 211
 212         /* Should sleep 1 ms */
 213         msleep(1);
 214
 215         /* Set DTR, Set RTS */
 216         sirdev_set_dtr_rts(dev, TRUE, TRUE);
 217
 218         /* Wait at least 50 us */
 219         udelay(75);
 220
 221         dev->speed = 9600;
 222
 223         return 0;
 224 }
 225
 226 MODULE_AUTHOR("Dag Brattli <dagb@cs.uit.no>");
 227 MODULE_DESCRIPTION("Tekram IrMate IR-210B dongle driver");
 228 MODULE_LICENSE("GPL");
 229 MODULE_ALIAS("irda-dongle-0"); /* IRDA_TEKRAM_DONGLE */
 230
 231 module_init(tekram_sir_init);
 232 module_exit(tekram_sir_cleanup);