litelink-sir.c
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/*********************************************************************
*
* Filename: litelink.c
* Version: 1.1
* Description: Driver for the Parallax LiteLink dongle
* Status: Stable
* Author: Dag Brattli <dagb@cs.uit.no>
* Created at: Fri May 7 12:50:33 1999
* Modified at: Fri Dec 17 09:14:23 1999
* Modified by: Dag Brattli <dagb@cs.uit.no>
*
* Copyright (c) 1999 Dag Brattli, All Rights Reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of
* the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see <http://www.gnu.org/licenses/>.
*
********************************************************************/
/*
* Modified at: Thu Jan 15 2003
* Modified by: Eugene Crosser <crosser@average.org>
*
* Convert to "new" IRDA infrastructure for kernel 2.6
*/
#include <linux/module.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <net/irda/irda.h>
#include "sir-dev.h"
#define MIN_DELAY 25 /* 15 us, but wait a little more to be sure */
#define MAX_DELAY 10000 /* 1 ms */
static int litelink_open(struct sir_dev *dev);
static int litelink_close(struct sir_dev *dev);
static int litelink_change_speed(struct sir_dev *dev, unsigned speed);
static int litelink_reset(struct sir_dev *dev);
/* These are the baudrates supported - 9600 must be last one! */
static unsigned baud_rates[] = { 115200, 57600, 38400, 19200, 9600 };
static struct dongle_driver litelink = {
.owner = THIS_MODULE,
.driver_name = "Parallax LiteLink",
.type = IRDA_LITELINK_DONGLE,
.open = litelink_open,
.close = litelink_close,
.reset = litelink_reset,
.set_speed = litelink_change_speed,
};
static int __init litelink_sir_init(void)
{
return irda_register_dongle(&litelink);
}
static void __exit litelink_sir_cleanup(void)
{
irda_unregister_dongle(&litelink);
}
static int litelink_open(struct sir_dev *dev)
{
struct qos_info *qos = &dev->qos;
IRDA_DEBUG(2, "%s()\n", __func__);
/* Power up dongle */
sirdev_set_dtr_rts(dev, TRUE, TRUE);
/* Set the speeds we can accept */
qos->baud_rate.bits &= IR_115200|IR_57600|IR_38400|IR_19200|IR_9600;
qos->min_turn_time.bits = 0x7f; /* Needs 0.01 ms */
irda_qos_bits_to_value(qos);
/* irda thread waits 50 msec for power settling */
return 0;
}
static int litelink_close(struct sir_dev *dev)
{
IRDA_DEBUG(2, "%s()\n", __func__);
/* Power off dongle */
sirdev_set_dtr_rts(dev, FALSE, FALSE);
return 0;
}
/*
* Function litelink_change_speed (task)
*
* Change speed of the Litelink dongle. To cycle through the available
* baud rates, pulse RTS low for a few ms.
*/
static int litelink_change_speed(struct sir_dev *dev, unsigned speed)
{
int i;
IRDA_DEBUG(2, "%s()\n", __func__);
/* dongle already reset by irda-thread - current speed (dongle and
* port) is the default speed (115200 for litelink!)
*/
/* Cycle through avaiable baudrates until we reach the correct one */
for (i = 0; baud_rates[i] != speed; i++) {
/* end-of-list reached due to invalid speed request */
if (baud_rates[i] == 9600)
break;
/* Set DTR, clear RTS */
sirdev_set_dtr_rts(dev, FALSE, TRUE);
/* Sleep a minimum of 15 us */
udelay(MIN_DELAY);
/* Set DTR, Set RTS */
sirdev_set_dtr_rts(dev, TRUE, TRUE);
/* Sleep a minimum of 15 us */
udelay(MIN_DELAY);
}
dev->speed = baud_rates[i];
/* invalid baudrate should not happen - but if, we return -EINVAL and
* the dongle configured for 9600 so the stack has a chance to recover
*/
return (dev->speed == speed) ? 0 : -EINVAL;
}
/*
* Function litelink_reset (task)
*
* Reset the Litelink type dongle.
*
*/
static int litelink_reset(struct sir_dev *dev)
{
IRDA_DEBUG(2, "%s()\n", __func__);
/* probably the power-up can be dropped here, but with only
* 15 usec delay it's not worth the risk unless somebody with
* the hardware confirms it doesn't break anything...
*/
/* Power on dongle */
sirdev_set_dtr_rts(dev, TRUE, TRUE);
/* Sleep a minimum of 15 us */
udelay(MIN_DELAY);
/* Clear RTS to reset dongle */
sirdev_set_dtr_rts(dev, TRUE, FALSE);
/* Sleep a minimum of 15 us */
udelay(MIN_DELAY);
/* Go back to normal mode */
sirdev_set_dtr_rts(dev, TRUE, TRUE);
/* Sleep a minimum of 15 us */
udelay(MIN_DELAY);
/* This dongles speed defaults to 115200 bps */
dev->speed = 115200;
return 0;
}
MODULE_AUTHOR("Dag Brattli <dagb@cs.uit.no>");
MODULE_DESCRIPTION("Parallax Litelink dongle driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("irda-dongle-5"); /* IRDA_LITELINK_DONGLE */
/*
* Function init_module (void)
*
* Initialize Litelink module
*
*/
module_init(litelink_sir_init);
/*
* Function cleanup_module (void)
*
* Cleanup Litelink module
*
*/
module_exit(litelink_sir_cleanup);