LXR linux/drivers/net/irda/mcp2120-sir.c

   1/*********************************************************************
   2 *            
   3 *    
   4 * Filename:      mcp2120.c
   5 * Version:       1.0
   6 * Description:   Implementation for the MCP2120 (Microchip)
   7 * Status:        Experimental.
   8 * Author:        Felix Tang (tangf@eyetap.org)
   9 * Created at:    Sun Mar 31 19:32:12 EST 2002
  10 * Based on code by:   Dag Brattli <dagb@cs.uit.no>
  11 * 
  12 *     Copyright (c) 2002 Felix Tang, 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 ********************************************************************/
  20
  21#include <linux/module.h>
  22#include <linux/delay.h>
  23#include <linux/init.h>
  24
  25#include <net/irda/irda.h>
  26
  27#include "sir-dev.h"
  28
  29static int mcp2120_reset(struct sir_dev *dev);
  30static int mcp2120_open(struct sir_dev *dev);
  31static int mcp2120_close(struct sir_dev *dev);
  32static int mcp2120_change_speed(struct sir_dev *dev, unsigned speed);
  33
  34#define MCP2120_9600    0x87
  35#define MCP2120_19200   0x8B
  36#define MCP2120_38400   0x85
  37#define MCP2120_57600   0x83
  38#define MCP2120_115200  0x81
  39
  40#define MCP2120_COMMIT  0x11
  41
  42static struct dongle_driver mcp2120 = {
  43        .owner          = THIS_MODULE,
  44        .driver_name    = "Microchip MCP2120",
  45        .type           = IRDA_MCP2120_DONGLE,
  46        .open           = mcp2120_open,
  47        .close          = mcp2120_close,
  48        .reset          = mcp2120_reset,
  49        .set_speed      = mcp2120_change_speed,
  50};
  51
  52static int __init mcp2120_sir_init(void)
  53{
  54        return irda_register_dongle(&mcp2120);
  55}
  56
  57static void __exit mcp2120_sir_cleanup(void)
  58{
  59        irda_unregister_dongle(&mcp2120);
  60}
  61
  62static int mcp2120_open(struct sir_dev *dev)
  63{
  64        struct qos_info *qos = &dev->qos;
  65
  66        /* seems no explicit power-on required here and reset switching it on anyway */
  67
  68        qos->baud_rate.bits &= IR_9600|IR_19200|IR_38400|IR_57600|IR_115200;
  69        qos->min_turn_time.bits = 0x01;
  70        irda_qos_bits_to_value(qos);
  71
  72        return 0;
  73}
  74
  75static int mcp2120_close(struct sir_dev *dev)
  76{
  77        /* Power off dongle */
  78        /* reset and inhibit mcp2120 */
  79        sirdev_set_dtr_rts(dev, TRUE, TRUE);
  80        // sirdev_set_dtr_rts(dev, FALSE, FALSE);
  81
  82        return 0;
  83}
  84
  85/*
  86 * Function mcp2120_change_speed (dev, speed)
  87 *
  88 *    Set the speed for the MCP2120.
  89 *
  90 */
  91
  92#define MCP2120_STATE_WAIT_SPEED        (SIRDEV_STATE_DONGLE_SPEED+1)
  93
  94static int mcp2120_change_speed(struct sir_dev *dev, unsigned speed)
  95{
  96        unsigned state = dev->fsm.substate;
  97        unsigned delay = 0;
  98        u8 control[2];
  99        static int ret = 0;
 100
 101        switch (state) {
 102        case SIRDEV_STATE_DONGLE_SPEED:
 103                /* Set DTR to enter command mode */
 104                sirdev_set_dtr_rts(dev, TRUE, FALSE);
 105                udelay(500);
 106
 107                ret = 0;
 108                switch (speed) {
 109                default:
 110                        speed = 9600;
 111                        ret = -EINVAL;
 112                        /* fall through */
 113                case 9600:
 114                        control[0] = MCP2120_9600;
 115                        //printk("mcp2120 9600\n");
 116                        break;
 117                case 19200:
 118                        control[0] = MCP2120_19200;
 119                        //printk("mcp2120 19200\n");
 120                        break;
 121                case 34800:
 122                        control[0] = MCP2120_38400;
 123                        //printk("mcp2120 38400\n");
 124                        break;
 125                case 57600:
 126                        control[0] = MCP2120_57600;
 127                        //printk("mcp2120 57600\n");
 128                        break;
 129                case 115200:
 130                        control[0] = MCP2120_115200;
 131                        //printk("mcp2120 115200\n");
 132                        break;
 133                }
 134                control[1] = MCP2120_COMMIT;
 135        
 136                /* Write control bytes */
 137                sirdev_raw_write(dev, control, 2);
 138                dev->speed = speed;
 139
 140                state = MCP2120_STATE_WAIT_SPEED;
 141                delay = 100;
 142                //printk("mcp2120_change_speed: dongle_speed\n");
 143                break;
 144
 145        case MCP2120_STATE_WAIT_SPEED:
 146                /* Go back to normal mode */
 147                sirdev_set_dtr_rts(dev, FALSE, FALSE);
 148                //printk("mcp2120_change_speed: mcp_wait\n");
 149                break;
 150
 151        default:
 152                net_err_ratelimited("%s(), undefine state %d\n",
 153                                    __func__, state);
 154                ret = -EINVAL;
 155                break;
 156        }
 157        dev->fsm.substate = state;
 158        return (delay > 0) ? delay : ret;
 159}
 160
 161/*
 162 * Function mcp2120_reset (driver)
 163 *
 164 *      This function resets the mcp2120 dongle.
 165 *      
 166 *      Info: -set RTS to reset mcp2120
 167 *            -set DTR to set mcp2120 software command mode
 168 *            -mcp2120 defaults to 9600 baud after reset
 169 *
 170 *      Algorithm:
 171 *      0. Set RTS to reset mcp2120.
 172 *      1. Clear RTS and wait for device reset timer of 30 ms (max).
 173 *      
 174 */
 175
 176#define MCP2120_STATE_WAIT1_RESET       (SIRDEV_STATE_DONGLE_RESET+1)
 177#define MCP2120_STATE_WAIT2_RESET       (SIRDEV_STATE_DONGLE_RESET+2)
 178
 179static int mcp2120_reset(struct sir_dev *dev)
 180{
 181        unsigned state = dev->fsm.substate;
 182        unsigned delay = 0;
 183        int ret = 0;
 184
 185        switch (state) {
 186        case SIRDEV_STATE_DONGLE_RESET:
 187                //printk("mcp2120_reset: dongle_reset\n");
 188                /* Reset dongle by setting RTS*/
 189                sirdev_set_dtr_rts(dev, TRUE, TRUE);
 190                state = MCP2120_STATE_WAIT1_RESET;
 191                delay = 50;
 192                break;
 193
 194        case MCP2120_STATE_WAIT1_RESET:
 195                //printk("mcp2120_reset: mcp2120_wait1\n");
 196                /* clear RTS and wait for at least 30 ms. */
 197                sirdev_set_dtr_rts(dev, FALSE, FALSE);
 198                state = MCP2120_STATE_WAIT2_RESET;
 199                delay = 50;
 200                break;
 201
 202        case MCP2120_STATE_WAIT2_RESET:
 203                //printk("mcp2120_reset mcp2120_wait2\n");
 204                /* Go back to normal mode */
 205                sirdev_set_dtr_rts(dev, FALSE, FALSE);
 206                break;
 207
 208        default:
 209                net_err_ratelimited("%s(), undefined state %d\n",
 210                                    __func__, state);
 211                ret = -EINVAL;
 212                break;
 213        }
 214        dev->fsm.substate = state;
 215        return (delay > 0) ? delay : ret;
 216}
 217
 218MODULE_AUTHOR("Felix Tang <tangf@eyetap.org>");
 219MODULE_DESCRIPTION("Microchip MCP2120");
 220MODULE_LICENSE("GPL");
 221MODULE_ALIAS("irda-dongle-9"); /* IRDA_MCP2120_DONGLE */
 222
 223module_init(mcp2120_sir_init);
 224module_exit(mcp2120_sir_cleanup);
 225