drivers/net/irda/actisys.c

   1 /*********************************************************************
   2  *
   3  * Filename:      actisys.c
   4  * Version:       1.0
   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  * Created at:    Wed Oct 21 20:02:35 1998
  11  * Modified at:   Fri Dec 17 09:10:43 1999
  12  * Modified by:   Dag Brattli <dagb@cs.uit.no>
  13  *
  14  *     Copyright (c) 1998-1999 Dag Brattli, All Rights Reserved.
  15  *     Copyright (c) 1999 Jean Tourrilhes
  16  *
  17  *     This program is free software; you can redistribute it and/or
  18  *     modify it under the terms of the GNU General Public License as
  19  *     published by the Free Software Foundation; either version 2 of
  20  *     the License, or (at your option) any later version.
  21  *
  22  *     Neither Dag Brattli nor University of Tromsø admit liability nor
  23  *     provide warranty for any of this software. This material is
  24  *     provided "AS-IS" and at no charge.
  25  *
  26  ********************************************************************/
  27
  28 /*
  29  * Changelog
  30  *
  31  * 0.8 -> 0.9999 - Jean
  32  *      o New initialisation procedure : much safer and correct
  33  *      o New procedure the change speed : much faster and simpler
  34  *      o Other cleanups & comments
  35  *      Thanks to Lichen Wang @ Actisys for his excellent help...
  36  */
  37
  38 #include <linux/module.h>
  39 #include <linux/delay.h>
  40 #include <linux/tty.h>
  41 #include <linux/init.h>
  42
  43 #include <net/irda/irda.h>
  44 #include <net/irda/irda_device.h>
  45
  46 /*
  47  * Define the timing of the pulses we send to the dongle (to reset it, and
  48  * to toggle speeds). Basically, the limit here is the propagation speed of
  49  * the signals through the serial port, the dongle being much faster.  Any
  50  * serial port support 115 kb/s, so we are sure that pulses 8.5 us wide can
  51  * go through cleanly . If you are on the wild side, you can try to lower
  52  * this value (Actisys recommended me 2 us, and 0 us work for me on a P233!)
  53  */
  54 #define MIN_DELAY 10    /* 10 us to be on the conservative side */
  55
  56 static int  actisys_change_speed(struct irda_task *task);
  57 static int  actisys_reset(struct irda_task *task);
  58 static void actisys_open(dongle_t *self, struct qos_info *qos);
  59 static void actisys_close(dongle_t *self);
  60
  61 /* These are the baudrates supported, in the order available */
  62 /* Note : the 220L doesn't support 38400, but we will fix that below */
  63 static __u32 baud_rates[] = { 9600, 19200, 57600, 115200, 38400 };
  64 #define MAX_SPEEDS 5
  65
  66 static struct dongle_reg dongle = {
  67         .type = IRDA_ACTISYS_DONGLE,
  68         .open = actisys_open,
  69         .close = actisys_close,
  70         .reset = actisys_reset,
  71         .change_speed = actisys_change_speed,
  72         .owner = THIS_MODULE,
  73 };
  74
  75 static struct dongle_reg dongle_plus = {
  76         .type = IRDA_ACTISYS_PLUS_DONGLE,
  77         .open = actisys_open,
  78         .close = actisys_close,
  79         .reset = actisys_reset,
  80         .change_speed = actisys_change_speed,
  81         .owner = THIS_MODULE,
  82 };
  83
  84 /*
  85  * Function actisys_change_speed (task)
  86  *
  87  *      There is two model of Actisys dongle we are dealing with,
  88  * the 220L and 220L+. At this point, only irattach knows with
  89  * kind the user has requested (it was an argument on irattach
  90  * command line).
  91  *      So, we register a dongle of each sort and let irattach
  92  * pick the right one...
  93  */
  94 static int __init actisys_init(void)
  95 {
  96         int ret;
  97
  98         /* First, register an Actisys 220L dongle */
  99         ret = irda_device_register_dongle(&dongle);
 100         if (ret < 0)
 101                 return ret;
 102         /* Now, register an Actisys 220L+ dongle */
 103         ret = irda_device_register_dongle(&dongle_plus);
 104         if (ret < 0) {
 105                 irda_device_unregister_dongle(&dongle);
 106                 return ret;
 107         }
 108         return 0;
 109 }
 110
 111 static void __exit actisys_cleanup(void)
 112 {
 113         /* We have to remove both dongles */
 114         irda_device_unregister_dongle(&dongle);
 115         irda_device_unregister_dongle(&dongle_plus);
 116 }
 117
 118 static void actisys_open(dongle_t *self, struct qos_info *qos)
 119 {
 120         /* Power on the dongle */
 121         self->set_dtr_rts(self->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 (self->issue->type == IRDA_ACTISYS_DONGLE)
 128                 qos->baud_rate.bits &= ~IR_38400;
 129
 130         qos->min_turn_time.bits = 0x7f; /* Needs 0.01 ms */
 131 }
 132
 133 static void actisys_close(dongle_t *self)
 134 {
 135         /* Power off the dongle */
 136         self->set_dtr_rts(self->dev, FALSE, FALSE);
 137 }
 138
 139 /*
 140  * Function actisys_change_speed (task)
 141  *
 142  *    Change speed of the ACTiSYS IR-220L and IR-220L+ type IrDA dongles.
 143  *    To cycle through the available baud rates, pulse RTS low for a few us.
 144  *
 145  *      First, we reset the dongle to always start from a known state.
 146  *      Then, we cycle through the speeds by pulsing RTS low and then up.
 147  *      The dongle allow us to pulse quite fast, se we can set speed in one go,
 148  * which is must faster ( < 100 us) and less complex than what is found
 149  * in some other dongle drivers...
 150  *      Note that even if the new speed is the same as the current speed,
 151  * we reassert the speed. This make sure that things are all right,
 152  * and it's fast anyway...
 153  *      By the way, this function will work for both type of dongles,
 154  * because the additional speed is at the end of the sequence...
 155  */
 156 static int actisys_change_speed(struct irda_task *task)
 157 {
 158         dongle_t *self = (dongle_t *) task->instance;
 159         __u32 speed = (__u32) task->param;      /* Target speed */
 160         int ret = 0;
 161         int i = 0;
 162
 163         IRDA_DEBUG(4, "%s(), speed=%d (was %d)\n", __FUNCTION__, speed,
 164                    self->speed);
 165
 166         /* Go to a known state by reseting the dongle */
 167
 168         /* Reset the dongle : set DTR low for 10 us */
 169         self->set_dtr_rts(self->dev, FALSE, TRUE);
 170         udelay(MIN_DELAY);
 171
 172         /* Go back to normal mode (we are now at 9600 b/s) */
 173         self->set_dtr_rts(self->dev, TRUE, TRUE);
 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                         self->speed = baud_rates[i];
 182                         break;
 183                 }
 184                 /* Make sure previous pulse is finished */
 185                 udelay(MIN_DELAY);
 186
 187                 /* Set RTS low for 10 us */
 188                 self->set_dtr_rts(self->dev, TRUE, FALSE);
 189                 udelay(MIN_DELAY);
 190
 191                 /* Set RTS high for 10 us */
 192                 self->set_dtr_rts(self->dev, TRUE, TRUE);
 193         }
 194
 195         /* Check if life is sweet... */
 196         if (i >= MAX_SPEEDS)
 197                 ret = -1;  /* This should not happen */
 198
 199         /* Basta lavoro, on se casse d'ici... */
 200         irda_task_next_state(task, IRDA_TASK_DONE);
 201
 202         return ret;
 203 }
 204
 205 /*
 206  * Function actisys_reset (task)
 207  *
 208  *      Reset the Actisys type dongle. Warning, this function must only be
 209  *      called with a process context!
 210  *
 211  * We need to do two things in this function :
 212  *      o first make sure that the dongle is in a state where it can operate
 213  *      o second put the dongle in a know state
 214  *
 215  *      The dongle is powered of the RTS and DTR lines. In the dongle, there
 216  * is a big capacitor to accommodate the current spikes. This capacitor
 217  * takes a least 50 ms to be charged. In theory, the Bios set those lines
 218  * up, so by the time we arrive here we should be set. It doesn't hurt
 219  * to be on the conservative side, so we will wait...
 220  *      Then, we set the speed to 9600 b/s to get in a known state (see in
 221  * change_speed for details). It is needed because the IrDA stack
 222  * has tried to set the speed immediately after our first return,
 223  * so before we can be sure the dongle is up and running.
 224  */
 225 static int actisys_reset(struct irda_task *task)
 226 {
 227         dongle_t *self = (dongle_t *) task->instance;
 228         int ret = 0;
 229
 230         IRDA_ASSERT(task != NULL, return -1;);
 231
 232         self->reset_task = task;
 233
 234         switch (task->state) {
 235         case IRDA_TASK_INIT:
 236                 /* Set both DTR & RTS to power up the dongle */
 237                 /* In theory redundant with power up in actisys_open() */
 238                 self->set_dtr_rts(self->dev, TRUE, TRUE);
 239
 240                 /* Sleep 50 ms to make sure capacitor is charged */
 241                 ret = msecs_to_jiffies(50);
 242                 irda_task_next_state(task, IRDA_TASK_WAIT);
 243                 break;
 244         case IRDA_TASK_WAIT:
 245                 /* Reset the dongle : set DTR low for 10 us */
 246                 self->set_dtr_rts(self->dev, FALSE, TRUE);
 247                 udelay(MIN_DELAY);
 248
 249                 /* Go back to normal mode */
 250                 self->set_dtr_rts(self->dev, TRUE, TRUE);
 251
 252                 irda_task_next_state(task, IRDA_TASK_DONE);
 253                 self->reset_task = NULL;
 254                 self->speed = 9600;     /* That's the default */
 255                 break;
 256         default:
 257                 IRDA_ERROR("%s(), unknown state %d\n",
 258                            __FUNCTION__, task->state);
 259                 irda_task_next_state(task, IRDA_TASK_DONE);
 260                 self->reset_task = NULL;
 261                 ret = -1;
 262                 break;
 263         }
 264         return ret;
 265 }
 266
 267 MODULE_AUTHOR("Dag Brattli <dagb@cs.uit.no> - Jean Tourrilhes <jt@hpl.hp.com>");
 268 MODULE_DESCRIPTION("ACTiSYS IR-220L and IR-220L+ dongle driver");
 269 MODULE_LICENSE("GPL");
 270 MODULE_ALIAS("irda-dongle-2"); /* IRDA_ACTISYS_DONGLE */
 271 MODULE_ALIAS("irda-dongle-3"); /* IRDA_ACTISYS_PLUS_DONGLE */
 272
 273
 274 /*
 275  * Function init_module (void)
 276  *
 277  *    Initialize Actisys module
 278  *
 279  */
 280 module_init(actisys_init);
 281
 282 /*
 283  * Function cleanup_module (void)
 284  *
 285  *    Cleanup Actisys module
 286  *
 287  */
 288 module_exit(actisys_cleanup);