drivers/net/irda/litelink.c

   1 /*********************************************************************
   2  *
   3  * Filename:      litelink.c
   4  * Version:       1.1
   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:   Fri Dec 17 09:14:23 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/init.h>
  35
  36 #include <net/irda/irda.h>
  37 #include <net/irda/irda_device.h>
  38
  39 #define MIN_DELAY 25      /* 15 us, but wait a little more to be sure */
  40 #define MAX_DELAY 10000   /* 1 ms */
  41
  42 static void litelink_open(dongle_t *self, struct qos_info *qos);
  43 static void litelink_close(dongle_t *self);
  44 static int  litelink_change_speed(struct irda_task *task);
  45 static int  litelink_reset(struct irda_task *task);
  46
  47 /* These are the baudrates supported */
  48 static __u32 baud_rates[] = { 115200, 57600, 38400, 19200, 9600 };
  49
  50 static struct dongle_reg dongle = {
  51         .type = IRDA_LITELINK_DONGLE,
  52         .open = litelink_open,
  53         .close = litelink_close,
  54         .reset = litelink_reset,
  55         .change_speed = litelink_change_speed,
  56         .owner = THIS_MODULE,
  57 };
  58
  59 static int __init litelink_init(void)
  60 {
  61         return irda_device_register_dongle(&dongle);
  62 }
  63
  64 static void __exit litelink_cleanup(void)
  65 {
  66         irda_device_unregister_dongle(&dongle);
  67 }
  68
  69 static void litelink_open(dongle_t *self, struct qos_info *qos)
  70 {
  71         qos->baud_rate.bits &= IR_9600|IR_19200|IR_38400|IR_57600|IR_115200;
  72         qos->min_turn_time.bits = 0x7f; /* Needs 0.01 ms */
  73 }
  74
  75 static void litelink_close(dongle_t *self)
  76 {
  77         /* Power off dongle */
  78         self->set_dtr_rts(self->dev, FALSE, FALSE);
  79 }
  80
  81 /*
  82  * Function litelink_change_speed (task)
  83  *
  84  *    Change speed of the Litelink dongle. To cycle through the available
  85  *    baud rates, pulse RTS low for a few ms.
  86  */
  87 static int litelink_change_speed(struct irda_task *task)
  88 {
  89         dongle_t *self = (dongle_t *) task->instance;
  90         __u32 speed = (__u32) task->param;
  91         int i;
  92
  93         /* Clear RTS to reset dongle */
  94         self->set_dtr_rts(self->dev, TRUE, FALSE);
  95
  96         /* Sleep a minimum of 15 us */
  97         udelay(MIN_DELAY);
  98
  99         /* Go back to normal mode */
 100         self->set_dtr_rts(self->dev, TRUE, TRUE);
 101
 102         /* Sleep a minimum of 15 us */
 103         udelay(MIN_DELAY);
 104
 105         /* Cycle through avaiable baudrates until we reach the correct one */
 106         for (i=0; i<5 && baud_rates[i] != speed; i++) {
 107                 /* Set DTR, clear RTS */
 108                 self->set_dtr_rts(self->dev, FALSE, TRUE);
 109
 110                 /* Sleep a minimum of 15 us */
 111                 udelay(MIN_DELAY);
 112
 113                 /* Set DTR, Set RTS */
 114                 self->set_dtr_rts(self->dev, TRUE, TRUE);
 115
 116                 /* Sleep a minimum of 15 us */
 117                 udelay(MIN_DELAY);
 118         }
 119         irda_task_next_state(task, IRDA_TASK_DONE);
 120
 121         return 0;
 122 }
 123
 124 /*
 125  * Function litelink_reset (task)
 126  *
 127  *      Reset the Litelink type dongle.
 128  *
 129  */
 130 static int litelink_reset(struct irda_task *task)
 131 {
 132         dongle_t *self = (dongle_t *) task->instance;
 133
 134         /* Power on dongle */
 135         self->set_dtr_rts(self->dev, TRUE, TRUE);
 136
 137         /* Sleep a minimum of 15 us */
 138         udelay(MIN_DELAY);
 139
 140         /* Clear RTS to reset dongle */
 141         self->set_dtr_rts(self->dev, TRUE, FALSE);
 142
 143         /* Sleep a minimum of 15 us */
 144         udelay(MIN_DELAY);
 145
 146         /* Go back to normal mode */
 147         self->set_dtr_rts(self->dev, TRUE, TRUE);
 148
 149         /* Sleep a minimum of 15 us */
 150         udelay(MIN_DELAY);
 151
 152         /* This dongles speed defaults to 115200 bps */
 153         self->speed = 115200;
 154
 155         irda_task_next_state(task, IRDA_TASK_DONE);
 156
 157         return 0;
 158 }
 159
 160 MODULE_AUTHOR("Dag Brattli <dagb@cs.uit.no>");
 161 MODULE_DESCRIPTION("Parallax Litelink dongle driver");
 162 MODULE_LICENSE("GPL");
 163 MODULE_ALIAS("irda-dongle-5"); /* IRDA_LITELINK_DONGLE */
 164
 165 /*
 166  * Function init_module (void)
 167  *
 168  *    Initialize Litelink module
 169  *
 170  */
 171 module_init(litelink_init);
 172
 173 /*
 174  * Function cleanup_module (void)
 175  *
 176  *    Cleanup Litelink module
 177  *
 178  */
 179 module_exit(litelink_cleanup);