mcp2120.c
/*********************************************************************
*
*
* Filename: mcp2120.c
* Version: 1.0
* Description: Implementation for the MCP2120 (Microchip)
* Status: Experimental.
* Author: Felix Tang (tangf@eyetap.org)
* Created at: Sun Mar 31 19:32:12 EST 2002
* Based on code by: Dag Brattli <dagb@cs.uit.no>
*
* Copyright (c) 2002 Felix Tang, 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.
*
********************************************************************/
#include <linux/module.h>
#include <linux/delay.h>
#include <linux/tty.h>
#include <linux/init.h>
#include <net/irda/irda.h>
#include <net/irda/irda_device.h>
static int mcp2120_reset(struct irda_task *task);
static void mcp2120_open(dongle_t *self, struct qos_info *qos);
static void mcp2120_close(dongle_t *self);
static int mcp2120_change_speed(struct irda_task *task);
#define MCP2120_9600 0x87
#define MCP2120_19200 0x8B
#define MCP2120_38400 0x85
#define MCP2120_57600 0x83
#define MCP2120_115200 0x81
#define MCP2120_COMMIT 0x11
static struct dongle_reg dongle = {
.type = IRDA_MCP2120_DONGLE,
.open = mcp2120_open,
.close = mcp2120_close,
.reset = mcp2120_reset,
.change_speed = mcp2120_change_speed,
.owner = THIS_MODULE,
};
static int __init mcp2120_init(void)
{
return irda_device_register_dongle(&dongle);
}
static void __exit mcp2120_cleanup(void)
{
irda_device_unregister_dongle(&dongle);
}
static void mcp2120_open(dongle_t *self, struct qos_info *qos)
{
qos->baud_rate.bits &= IR_9600|IR_19200|IR_38400|IR_57600|IR_115200;
qos->min_turn_time.bits = 0x01;
}
static void mcp2120_close(dongle_t *self)
{
/* Power off dongle */
/* reset and inhibit mcp2120 */
self->set_dtr_rts(self->dev, TRUE, TRUE);
//self->set_dtr_rts(self->dev, FALSE, FALSE);
}
/*
* Function mcp2120_change_speed (dev, speed)
*
* Set the speed for the MCP2120.
*
*/
static int mcp2120_change_speed(struct irda_task *task)
{
dongle_t *self = (dongle_t *) task->instance;
__u32 speed = (__u32) task->param;
__u8 control[2];
int ret = 0;
self->speed_task = task;
switch (task->state) {
case IRDA_TASK_INIT:
/* Need to reset the dongle and go to 9600 bps before
programming */
//printk("Dmcp2120_change_speed irda_task_init\n");
if (irda_task_execute(self, mcp2120_reset, NULL, task,
(void *) speed))
{
/* Dongle need more time to reset */
irda_task_next_state(task, IRDA_TASK_CHILD_WAIT);
/* Give reset 1 sec to finish */
ret = msecs_to_jiffies(1000);
}
break;
case IRDA_TASK_CHILD_WAIT:
IRDA_WARNING("%s(), resetting dongle timed out!\n",
__FUNCTION__);
ret = -1;
break;
case IRDA_TASK_CHILD_DONE:
/* Set DTR to enter command mode */
self->set_dtr_rts(self->dev, TRUE, FALSE);
udelay(500);
switch (speed) {
case 9600:
default:
control[0] = MCP2120_9600;
//printk("mcp2120 9600\n");
break;
case 19200:
control[0] = MCP2120_19200;
//printk("mcp2120 19200\n");
break;
case 34800:
control[0] = MCP2120_38400;
//printk("mcp2120 38400\n");
break;
case 57600:
control[0] = MCP2120_57600;
//printk("mcp2120 57600\n");
break;
case 115200:
control[0] = MCP2120_115200;
//printk("mcp2120 115200\n");
break;
}
control[1] = MCP2120_COMMIT;
/* Write control bytes */
self->write(self->dev, control, 2);
irda_task_next_state(task, IRDA_TASK_WAIT);
ret = msecs_to_jiffies(100);
//printk("mcp2120_change_speed irda_child_done\n");
break;
case IRDA_TASK_WAIT:
/* Go back to normal mode */
self->set_dtr_rts(self->dev, FALSE, FALSE);
irda_task_next_state(task, IRDA_TASK_DONE);
self->speed_task = NULL;
//printk("mcp2120_change_speed irda_task_wait\n");
break;
default:
IRDA_ERROR("%s(), unknown state %d\n",
__FUNCTION__, task->state);
irda_task_next_state(task, IRDA_TASK_DONE);
self->speed_task = NULL;
ret = -1;
break;
}
return ret;
}
/*
* Function mcp2120_reset (driver)
*
* This function resets the mcp2120 dongle.
*
* Info: -set RTS to reset mcp2120
* -set DTR to set mcp2120 software command mode
* -mcp2120 defaults to 9600 baud after reset
*
* Algorithm:
* 0. Set RTS to reset mcp2120.
* 1. Clear RTS and wait for device reset timer of 30 ms (max).
*
*/
static int mcp2120_reset(struct irda_task *task)
{
dongle_t *self = (dongle_t *) task->instance;
int ret = 0;
self->reset_task = task;
switch (task->state) {
case IRDA_TASK_INIT:
//printk("mcp2120_reset irda_task_init\n");
/* Reset dongle by setting RTS*/
self->set_dtr_rts(self->dev, TRUE, TRUE);
irda_task_next_state(task, IRDA_TASK_WAIT1);
ret = msecs_to_jiffies(50);
break;
case IRDA_TASK_WAIT1:
//printk("mcp2120_reset irda_task_wait1\n");
/* clear RTS and wait for at least 30 ms. */
self->set_dtr_rts(self->dev, FALSE, FALSE);
irda_task_next_state(task, IRDA_TASK_WAIT2);
ret = msecs_to_jiffies(50);
break;
case IRDA_TASK_WAIT2:
//printk("mcp2120_reset irda_task_wait2\n");
/* Go back to normal mode */
self->set_dtr_rts(self->dev, FALSE, FALSE);
irda_task_next_state(task, IRDA_TASK_DONE);
self->reset_task = NULL;
break;
default:
IRDA_ERROR("%s(), unknown state %d\n",
__FUNCTION__, task->state);
irda_task_next_state(task, IRDA_TASK_DONE);
self->reset_task = NULL;
ret = -1;
break;
}
return ret;
}
MODULE_AUTHOR("Felix Tang <tangf@eyetap.org>");
MODULE_DESCRIPTION("Microchip MCP2120");
MODULE_LICENSE("GPL");
MODULE_ALIAS("irda-dongle-9"); /* IRDA_MCP2120_DONGLE */
/*
* Function init_module (void)
*
* Initialize MCP2120 module
*
*/
module_init(mcp2120_init);
/*
* Function cleanup_module (void)
*
* Cleanup MCP2120 module
*
*/
module_exit(mcp2120_cleanup);