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         pr_debug("%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         sirdev_set_dtr_rts(dev, TRUE, TRUE);
  81
  82         qos->baud_rate.bits &= IR_9600|IR_19200|IR_38400|IR_57600|IR_115200;
  83         qos->min_turn_time.bits = 0x01; /* Needs at least 10 ms */
  84         irda_qos_bits_to_value(qos);
  85
  86         /* irda thread waits 50 msec for power settling */
  87
  88         return 0;
  89 }
  90
  91 static int tekram_close(struct sir_dev *dev)
  92 {
  93         /* Power off dongle */
  94         sirdev_set_dtr_rts(dev, FALSE, FALSE);
  95
  96         return 0;
  97 }
  98
  99 /*
 100  * Function tekram_change_speed (dev, state, speed)
 101  *
 102  *    Set the speed for the Tekram IRMate 210 type dongle. Warning, this
 103  *    function must be called with a process context!
 104  *
 105  *    Algorithm
 106  *    1. clear DTR
 107  *    2. set RTS, and wait at least 7 us
 108  *    3. send Control Byte to the IR-210 through TXD to set new baud rate
 109  *       wait until the stop bit of Control Byte is sent (for 9600 baud rate,
 110  *       it takes about 100 msec)
 111  *
 112  *      [oops, why 100 msec? sending 1 byte (10 bits) takes 1.05 msec
 113  *       - is this probably to compensate for delays in tty layer?]
 114  *
 115  *    5. clear RTS (return to NORMAL Operation)
 116  *    6. wait at least 50 us, new setting (baud rate, etc) takes effect here
 117  *       after
 118  */
 119
 120 #define TEKRAM_STATE_WAIT_SPEED (SIRDEV_STATE_DONGLE_SPEED + 1)
 121
 122 static int tekram_change_speed(struct sir_dev *dev, unsigned speed)
 123 {
 124         unsigned state = dev->fsm.substate;
 125         unsigned delay = 0;
 126         u8 byte;
 127         static int ret = 0;
 128
 129         switch(state) {
 130         case SIRDEV_STATE_DONGLE_SPEED:
 131
 132                 switch (speed) {
 133                 default:
 134                         speed = 9600;
 135                         ret = -EINVAL;
 136                         /* fall thru */
 137                 case 9600:
 138                         byte = TEKRAM_PW|TEKRAM_9600;
 139                         break;
 140                 case 19200:
 141                         byte = TEKRAM_PW|TEKRAM_19200;
 142                         break;
 143                 case 38400:
 144                         byte = TEKRAM_PW|TEKRAM_38400;
 145                         break;
 146                 case 57600:
 147                         byte = TEKRAM_PW|TEKRAM_57600;
 148                         break;
 149                 case 115200:
 150                         byte = TEKRAM_115200;
 151                         break;
 152                 }
 153
 154                 /* Set DTR, Clear RTS */
 155                 sirdev_set_dtr_rts(dev, TRUE, FALSE);
 156
 157                 /* Wait at least 7us */
 158                 udelay(14);
 159
 160                 /* Write control byte */
 161                 sirdev_raw_write(dev, &byte, 1);
 162
 163                 dev->speed = speed;
 164
 165                 state = TEKRAM_STATE_WAIT_SPEED;
 166                 delay = tekram_delay;
 167                 break;
 168
 169         case TEKRAM_STATE_WAIT_SPEED:
 170                 /* Set DTR, Set RTS */
 171                 sirdev_set_dtr_rts(dev, TRUE, TRUE);
 172                 udelay(50);
 173                 break;
 174
 175         default:
 176                 net_err_ratelimited("%s - undefined state %d\n",
 177                                     __func__, state);
 178                 ret = -EINVAL;
 179                 break;
 180         }
 181
 182         dev->fsm.substate = state;
 183         return (delay > 0) ? delay : ret;
 184 }
 185
 186 /*
 187  * Function tekram_reset (driver)
 188  *
 189  *      This function resets the tekram dongle. Warning, this function
 190  *      must be called with a process context!!
 191  *
 192  *      Algorithm:
 193  *        0. Clear RTS and DTR, and wait 50 ms (power off the IR-210 )
 194  *        1. clear RTS
 195  *        2. set DTR, and wait at least 1 ms
 196  *        3. clear DTR to SPACE state, wait at least 50 us for further
 197  *         operation
 198  */
 199
 200 static int tekram_reset(struct sir_dev *dev)
 201 {
 202         /* Clear DTR, Set RTS */
 203         sirdev_set_dtr_rts(dev, FALSE, TRUE);
 204
 205         /* Should sleep 1 ms */
 206         msleep(1);
 207
 208         /* Set DTR, Set RTS */
 209         sirdev_set_dtr_rts(dev, TRUE, TRUE);
 210
 211         /* Wait at least 50 us */
 212         udelay(75);
 213
 214         dev->speed = 9600;
 215
 216         return 0;
 217 }
 218
 219 MODULE_AUTHOR("Dag Brattli <dagb@cs.uit.no>");
 220 MODULE_DESCRIPTION("Tekram IrMate IR-210B dongle driver");
 221 MODULE_LICENSE("GPL");
 222 MODULE_ALIAS("irda-dongle-0"); /* IRDA_TEKRAM_DONGLE */
 223
 224 module_init(tekram_sir_init);
 225 module_exit(tekram_sir_cleanup);