drivers/net/irda/litelink.c

   1 /*********************************************************************
   2  *
   3  * Filename:      litelink.c
   4  * Version:       1.0
   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:   Wed May 19 07:25:15 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 #include <linux/module.h>
  32 #include <linux/delay.h>
  33 #include <linux/tty.h>
  34 #include <linux/sched.h>
  35 #include <linux/init.h>
  36
  37 #include <net/irda/irda.h>
  38 #include <net/irda/irmod.h>
  39 #include <net/irda/irda_device.h>
  40 #include <net/irda/dongle.h>
  41
  42 #define MIN_DELAY 25      /* 15 us, but wait a little more to be sure */
  43 #define MAX_DELAY 10000   /* 1 ms */
  44
  45 static void litelink_open(struct irda_device *idev, int type);
  46 static void litelink_close(struct irda_device *dev);
  47 static void litelink_change_speed(struct irda_device *dev, int baudrate);
  48 static void litelink_reset(struct irda_device *dev);
  49 static void litelink_init_qos(struct irda_device *idev, struct qos_info *qos);
  50
  51 /* These are the baudrates supported */
  52 static int baud_rates[] = { 115200, 57600, 38400, 19200, 9600 };
  53
  54 static struct dongle dongle = {
  55         LITELINK_DONGLE,
  56         litelink_open,
  57         litelink_close,
  58         litelink_reset,
  59         litelink_change_speed,
  60         litelink_init_qos,
  61 };
  62
  63 __initfunc(int litelink_init(void))
  64 {
  65         return irda_device_register_dongle(&dongle);
  66 }
  67
  68 void litelink_cleanup(void)
  69 {
  70         irda_device_unregister_dongle(&dongle);
  71 }
  72
  73 static void litelink_open(struct irda_device *idev, int type)
  74 {
  75         strcat(idev->description, " <-> litelink");
  76
  77         idev->io.dongle_id = type;
  78         idev->flags |= IFF_DONGLE;
  79
  80         MOD_INC_USE_COUNT;
  81 }
  82
  83 static void litelink_close(struct irda_device *idev)
  84 {
  85         /* Power off dongle */
  86         irda_device_set_dtr_rts(idev, FALSE, FALSE);
  87
  88         MOD_DEC_USE_COUNT;
  89 }
  90
  91 /*
  92  * Function litelink_change_speed (tty, baud)
  93  *
  94  *    Change speed of the Litelink dongle. To cycle through the available
  95  *    baud rates, pulse RTS low for a few ms.
  96  */
  97 static void litelink_change_speed(struct irda_device *idev, int baudrate)
  98 {
  99         int i;
 100
 101         ASSERT(idev != NULL, return;);
 102         ASSERT(idev->magic == IRDA_DEVICE_MAGIC, return;);
 103
 104         /* Clear RTS to reset dongle */
 105         irda_device_set_dtr_rts(idev, TRUE, FALSE);
 106
 107         /* Sleep a minimum of 15 us */
 108         udelay(MIN_DELAY);
 109
 110         /* Go back to normal mode */
 111         irda_device_set_dtr_rts(idev, TRUE, TRUE);
 112
 113         /* Sleep a minimum of 15 us */
 114         udelay(MIN_DELAY);
 115
 116         /* Cycle through avaiable baudrates until we reach the correct one */
 117         for (i=0; i<5 && baud_rates[i] != baudrate; i++) {
 118
 119                 /* Set DTR, clear RTS */
 120                 irda_device_set_dtr_rts(idev, FALSE, TRUE);
 121
 122                 /* Sleep a minimum of 15 us */
 123                 udelay(MIN_DELAY);
 124
 125                 /* Set DTR, Set RTS */
 126                 irda_device_set_dtr_rts(idev, TRUE, TRUE);
 127
 128                 /* Sleep a minimum of 15 us */
 129                 udelay(MIN_DELAY);
 130         }
 131 }
 132
 133 /*
 134  * Function litelink_reset (dev)
 135  *
 136  *      Reset the Litelink type dongle. Warning, this function must only be
 137  *      called with a process context!
 138  *
 139  */
 140 static void litelink_reset(struct irda_device *idev)
 141 {
 142         ASSERT(idev != NULL, return;);
 143         ASSERT(idev->magic == IRDA_DEVICE_MAGIC, return;);
 144
 145         /* Power on dongle */
 146         irda_device_set_dtr_rts(idev, TRUE, TRUE);
 147
 148         /* Sleep a minimum of 15 us */
 149         udelay(MIN_DELAY);
 150
 151         /* Clear RTS to reset dongle */
 152         irda_device_set_dtr_rts(idev, TRUE, FALSE);
 153
 154         /* Sleep a minimum of 15 us */
 155         udelay(MIN_DELAY);
 156
 157         /* Go back to normal mode */
 158         irda_device_set_dtr_rts(idev, TRUE, TRUE);
 159
 160         /* Sleep a minimum of 15 us */
 161         udelay(MIN_DELAY);
 162
 163         /* This dongles speed defaults to 115200 bps */
 164         idev->qos.baud_rate.value = 115200;
 165 }
 166
 167 /*
 168  * Function litelink_init_qos (qos)
 169  *
 170  *    Initialize QoS capabilities
 171  *
 172  */
 173 static void litelink_init_qos(struct irda_device *idev, struct qos_info *qos)
 174 {
 175         qos->baud_rate.bits &= IR_9600|IR_19200|IR_38400|IR_57600|IR_115200;
 176         qos->min_turn_time.bits &= 0x40; /* Needs 0.01 ms */
 177 }
 178
 179 #ifdef MODULE
 180
 181 MODULE_AUTHOR("Dag Brattli <dagb@cs.uit.no>");
 182 MODULE_DESCRIPTION("Parallax Litelink dongle driver");
 183
 184 /*
 185  * Function init_module (void)
 186  *
 187  *    Initialize Litelink module
 188  *
 189  */
 190 int init_module(void)
 191 {
 192         return litelink_init();
 193 }
 194
 195 /*
 196  * Function cleanup_module (void)
 197  *
 198  *    Cleanup Litelink module
 199  *
 200  */
 201 void cleanup_module(void)
 202 {
 203         litelink_cleanup();
 204 }
 205
 206 #endif