drivers/net/irda/actisys-sir.c

   1 /*********************************************************************
   2  *
   3  * Filename:      actisys.c
   4  * Version:       1.1
   5  * Description:   Implementation for the ACTiSYS IR-220L and IR-220L+
   6  *                dongles
   7  * Status:        Beta.
   8  * Authors:       Dag Brattli <dagb@cs.uit.no> (initially)
   9  *                Jean Tourrilhes <jt@hpl.hp.com> (new version)
  10  *                Martin Diehl <mad@mdiehl.de> (new version for sir_dev)
  11  * Created at:    Wed Oct 21 20:02:35 1998
  12  * Modified at:   Sun Oct 27 22:02:13 2002
  13  * Modified by:   Martin Diehl <mad@mdiehl.de>
  14  *
  15  *     Copyright (c) 1998-1999 Dag Brattli, All Rights Reserved.
  16  *     Copyright (c) 1999 Jean Tourrilhes
  17  *     Copyright (c) 2002 Martin Diehl
  18  *
  19  *     This program is free software; you can redistribute it and/or
  20  *     modify it under the terms of the GNU General Public License as
  21  *     published by the Free Software Foundation; either version 2 of
  22  *     the License, or (at your option) any later version.
  23  *
  24  *     Neither Dag Brattli nor University of Tromsø admit liability nor
  25  *     provide warranty for any of this software. This material is
  26  *     provided "AS-IS" and at no charge.
  27  *
  28  ********************************************************************/
  29
  30 /*
  31  * Changelog
  32  *
  33  * 0.8 -> 0.9999 - Jean
  34  *      o New initialisation procedure : much safer and correct
  35  *      o New procedure the change speed : much faster and simpler
  36  *      o Other cleanups & comments
  37  *      Thanks to Lichen Wang @ Actisys for his excellent help...
  38  *
  39  * 1.0 -> 1.1 - Martin Diehl
  40  *      modified for new sir infrastructure
  41  */
  42
  43 #include <linux/module.h>
  44 #include <linux/delay.h>
  45 #include <linux/init.h>
  46
  47 #include <net/irda/irda.h>
  48
  49 #include "sir-dev.h"
  50
  51 /*
  52  * Define the timing of the pulses we send to the dongle (to reset it, and
  53  * to toggle speeds). Basically, the limit here is the propagation speed of
  54  * the signals through the serial port, the dongle being much faster.  Any
  55  * serial port support 115 kb/s, so we are sure that pulses 8.5 us wide can
  56  * go through cleanly . If you are on the wild side, you can try to lower
  57  * this value (Actisys recommended me 2 us, and 0 us work for me on a P233!)
  58  */
  59 #define MIN_DELAY 10    /* 10 us to be on the conservative side */
  60
  61 static int actisys_open(struct sir_dev *);
  62 static int actisys_close(struct sir_dev *);
  63 static int actisys_change_speed(struct sir_dev *, unsigned);
  64 static int actisys_reset(struct sir_dev *);
  65
  66 /* These are the baudrates supported, in the order available */
  67 /* Note : the 220L doesn't support 38400, but we will fix that below */
  68 static unsigned baud_rates[] = { 9600, 19200, 57600, 115200, 38400 };
  69
  70 #define MAX_SPEEDS ARRAY_SIZE(baud_rates)
  71
  72 static struct dongle_driver act220l = {
  73         .owner          = THIS_MODULE,
  74         .driver_name    = "Actisys ACT-220L",
  75         .type           = IRDA_ACTISYS_DONGLE,
  76         .open           = actisys_open,
  77         .close          = actisys_close,
  78         .reset          = actisys_reset,
  79         .set_speed      = actisys_change_speed,
  80 };
  81
  82 static struct dongle_driver act220l_plus = {
  83         .owner          = THIS_MODULE,
  84         .driver_name    = "Actisys ACT-220L+",
  85         .type           = IRDA_ACTISYS_PLUS_DONGLE,
  86         .open           = actisys_open,
  87         .close          = actisys_close,
  88         .reset          = actisys_reset,
  89         .set_speed      = actisys_change_speed,
  90 };
  91
  92 static int __init actisys_sir_init(void)
  93 {
  94         int ret;
  95
  96         /* First, register an Actisys 220L dongle */
  97         ret = irda_register_dongle(&act220l);
  98         if (ret < 0)
  99                 return ret;
 100
 101         /* Now, register an Actisys 220L+ dongle */
 102         ret = irda_register_dongle(&act220l_plus);
 103         if (ret < 0) {
 104                 irda_unregister_dongle(&act220l);
 105                 return ret;
 106         }
 107         return 0;
 108 }
 109
 110 static void __exit actisys_sir_cleanup(void)
 111 {
 112         /* We have to remove both dongles */
 113         irda_unregister_dongle(&act220l_plus);
 114         irda_unregister_dongle(&act220l);
 115 }
 116
 117 static int actisys_open(struct sir_dev *dev)
 118 {
 119         struct qos_info *qos = &dev->qos;
 120
 121         sirdev_set_dtr_rts(dev, TRUE, TRUE);
 122
 123         /* Set the speeds we can accept */
 124         qos->baud_rate.bits &= IR_9600|IR_19200|IR_38400|IR_57600|IR_115200;
 125
 126         /* Remove support for 38400 if this is not a 220L+ dongle */
 127         if (dev->dongle_drv->type == IRDA_ACTISYS_DONGLE)
 128                 qos->baud_rate.bits &= ~IR_38400;
 129
 130         qos->min_turn_time.bits = 0x7f; /* Needs 0.01 ms */
 131         irda_qos_bits_to_value(qos);
 132
 133         /* irda thread waits 50 msec for power settling */
 134
 135         return 0;
 136 }
 137
 138 static int actisys_close(struct sir_dev *dev)
 139 {
 140         /* Power off the dongle */
 141         sirdev_set_dtr_rts(dev, FALSE, FALSE);
 142
 143         return 0;
 144 }
 145
 146 /*
 147  * Function actisys_change_speed (task)
 148  *
 149  *    Change speed of the ACTiSYS IR-220L and IR-220L+ type IrDA dongles.
 150  *    To cycle through the available baud rates, pulse RTS low for a few us.
 151  *
 152  *      First, we reset the dongle to always start from a known state.
 153  *      Then, we cycle through the speeds by pulsing RTS low and then up.
 154  *      The dongle allow us to pulse quite fast, se we can set speed in one go,
 155  * which is must faster ( < 100 us) and less complex than what is found
 156  * in some other dongle drivers...
 157  *      Note that even if the new speed is the same as the current speed,
 158  * we reassert the speed. This make sure that things are all right,
 159  * and it's fast anyway...
 160  *      By the way, this function will work for both type of dongles,
 161  * because the additional speed is at the end of the sequence...
 162  */
 163 static int actisys_change_speed(struct sir_dev *dev, unsigned speed)
 164 {
 165         int ret = 0;
 166         int i = 0;
 167
 168         IRDA_DEBUG(4, "%s(), speed=%d (was %d)\n", __func__,
 169                 speed, dev->speed);
 170
 171         /* dongle was already resetted from irda_request state machine,
 172          * we are in known state (dongle default)
 173          */
 174
 175         /*
 176          * Now, we can set the speed requested. Send RTS pulses until we
 177          * reach the target speed
 178          */
 179         for (i = 0; i < MAX_SPEEDS; i++) {
 180                 if (speed == baud_rates[i]) {
 181                         dev->speed = speed;
 182                         break;
 183                 }
 184                 /* Set RTS low for 10 us */
 185                 sirdev_set_dtr_rts(dev, TRUE, FALSE);
 186                 udelay(MIN_DELAY);
 187
 188                 /* Set RTS high for 10 us */
 189                 sirdev_set_dtr_rts(dev, TRUE, TRUE);
 190                 udelay(MIN_DELAY);
 191         }
 192
 193         /* Check if life is sweet... */
 194         if (i >= MAX_SPEEDS) {
 195                 actisys_reset(dev);
 196                 ret = -EINVAL;  /* This should not happen */
 197         }
 198
 199         /* Basta lavoro, on se casse d'ici... */
 200         return ret;
 201 }
 202
 203 /*
 204  * Function actisys_reset (task)
 205  *
 206  *      Reset the Actisys type dongle. Warning, this function must only be
 207  *      called with a process context!
 208  *
 209  * We need to do two things in this function :
 210  *      o first make sure that the dongle is in a state where it can operate
 211  *      o second put the dongle in a know state
 212  *
 213  *      The dongle is powered of the RTS and DTR lines. In the dongle, there
 214  * is a big capacitor to accommodate the current spikes. This capacitor
 215  * takes a least 50 ms to be charged. In theory, the Bios set those lines
 216  * up, so by the time we arrive here we should be set. It doesn't hurt
 217  * to be on the conservative side, so we will wait...
 218  * <Martin : move above comment to irda_config_fsm>
 219  *      Then, we set the speed to 9600 b/s to get in a known state (see in
 220  * change_speed for details). It is needed because the IrDA stack
 221  * has tried to set the speed immediately after our first return,
 222  * so before we can be sure the dongle is up and running.
 223  */
 224
 225 static int actisys_reset(struct sir_dev *dev)
 226 {
 227         /* Reset the dongle : set DTR low for 10 us */
 228         sirdev_set_dtr_rts(dev, FALSE, TRUE);
 229         udelay(MIN_DELAY);
 230
 231         /* Go back to normal mode */
 232         sirdev_set_dtr_rts(dev, TRUE, TRUE);
 233
 234         dev->speed = 9600;      /* That's the default */
 235
 236         return 0;
 237 }
 238
 239 MODULE_AUTHOR("Dag Brattli <dagb@cs.uit.no> - Jean Tourrilhes <jt@hpl.hp.com>");
 240 MODULE_DESCRIPTION("ACTiSYS IR-220L and IR-220L+ dongle driver");
 241 MODULE_LICENSE("GPL");
 242 MODULE_ALIAS("irda-dongle-2"); /* IRDA_ACTISYS_DONGLE */
 243 MODULE_ALIAS("irda-dongle-3"); /* IRDA_ACTISYS_PLUS_DONGLE */
 244
 245 module_init(actisys_sir_init);
 246 module_exit(actisys_sir_cleanup);