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
  29 static int mcp2120_reset(struct sir_dev *dev);
  30 static int mcp2120_open(struct sir_dev *dev);
  31 static int mcp2120_close(struct sir_dev *dev);
  32 static 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
  42 static 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
  52 static int __init mcp2120_sir_init(void)
  53 {
  54         return irda_register_dongle(&mcp2120);
  55 }
  56
  57 static void __exit mcp2120_sir_cleanup(void)
  58 {
  59         irda_unregister_dongle(&mcp2120);
  60 }
  61
  62 static int mcp2120_open(struct sir_dev *dev)
  63 {
  64         struct qos_info *qos = &dev->qos;
  65
  66         IRDA_DEBUG(2, "%s()\n", __func__);
  67
  68         /* seems no explicit power-on required here and reset switching it on anyway */
  69
  70         qos->baud_rate.bits &= IR_9600|IR_19200|IR_38400|IR_57600|IR_115200;
  71         qos->min_turn_time.bits = 0x01;
  72         irda_qos_bits_to_value(qos);
  73
  74         return 0;
  75 }
  76
  77 static int mcp2120_close(struct sir_dev *dev)
  78 {
  79         IRDA_DEBUG(2, "%s()\n", __func__);
  80
  81         /* Power off dongle */
  82         /* reset and inhibit mcp2120 */
  83         sirdev_set_dtr_rts(dev, TRUE, TRUE);
  84         // sirdev_set_dtr_rts(dev, FALSE, FALSE);
  85
  86         return 0;
  87 }
  88
  89 /*
  90  * Function mcp2120_change_speed (dev, speed)
  91  *
  92  *    Set the speed for the MCP2120.
  93  *
  94  */
  95
  96 #define MCP2120_STATE_WAIT_SPEED        (SIRDEV_STATE_DONGLE_SPEED+1)
  97
  98 static int mcp2120_change_speed(struct sir_dev *dev, unsigned speed)
  99 {
 100         unsigned state = dev->fsm.substate;
 101         unsigned delay = 0;
 102         u8 control[2];
 103         static int ret = 0;
 104
 105         IRDA_DEBUG(2, "%s()\n", __func__);
 106
 107         switch (state) {
 108         case SIRDEV_STATE_DONGLE_SPEED:
 109                 /* Set DTR to enter command mode */
 110                 sirdev_set_dtr_rts(dev, TRUE, FALSE);
 111                 udelay(500);
 112
 113                 ret = 0;
 114                 switch (speed) {
 115                 default:
 116                         speed = 9600;
 117                         ret = -EINVAL;
 118                         /* fall through */
 119                 case 9600:
 120                         control[0] = MCP2120_9600;
 121                         //printk("mcp2120 9600\n");
 122                         break;
 123                 case 19200:
 124                         control[0] = MCP2120_19200;
 125                         //printk("mcp2120 19200\n");
 126                         break;
 127                 case 34800:
 128                         control[0] = MCP2120_38400;
 129                         //printk("mcp2120 38400\n");
 130                         break;
 131                 case 57600:
 132                         control[0] = MCP2120_57600;
 133                         //printk("mcp2120 57600\n");
 134                         break;
 135                 case 115200:
 136                         control[0] = MCP2120_115200;
 137                         //printk("mcp2120 115200\n");
 138                         break;
 139                 }
 140                 control[1] = MCP2120_COMMIT;
 141
 142                 /* Write control bytes */
 143                 sirdev_raw_write(dev, control, 2);
 144                 dev->speed = speed;
 145
 146                 state = MCP2120_STATE_WAIT_SPEED;
 147                 delay = 100;
 148                 //printk("mcp2120_change_speed: dongle_speed\n");
 149                 break;
 150
 151         case MCP2120_STATE_WAIT_SPEED:
 152                 /* Go back to normal mode */
 153                 sirdev_set_dtr_rts(dev, FALSE, FALSE);
 154                 //printk("mcp2120_change_speed: mcp_wait\n");
 155                 break;
 156
 157         default:
 158                 IRDA_ERROR("%s(), undefine state %d\n", __func__, state);
 159                 ret = -EINVAL;
 160                 break;
 161         }
 162         dev->fsm.substate = state;
 163         return (delay > 0) ? delay : ret;
 164 }
 165
 166 /*
 167  * Function mcp2120_reset (driver)
 168  *
 169  *      This function resets the mcp2120 dongle.
 170  *
 171  *      Info: -set RTS to reset mcp2120
 172  *            -set DTR to set mcp2120 software command mode
 173  *            -mcp2120 defaults to 9600 baud after reset
 174  *
 175  *      Algorithm:
 176  *      0. Set RTS to reset mcp2120.
 177  *      1. Clear RTS and wait for device reset timer of 30 ms (max).
 178  *
 179  */
 180
 181 #define MCP2120_STATE_WAIT1_RESET       (SIRDEV_STATE_DONGLE_RESET+1)
 182 #define MCP2120_STATE_WAIT2_RESET       (SIRDEV_STATE_DONGLE_RESET+2)
 183
 184 static int mcp2120_reset(struct sir_dev *dev)
 185 {
 186         unsigned state = dev->fsm.substate;
 187         unsigned delay = 0;
 188         int ret = 0;
 189
 190         IRDA_DEBUG(2, "%s()\n", __func__);
 191
 192         switch (state) {
 193         case SIRDEV_STATE_DONGLE_RESET:
 194                 //printk("mcp2120_reset: dongle_reset\n");
 195                 /* Reset dongle by setting RTS*/
 196                 sirdev_set_dtr_rts(dev, TRUE, TRUE);
 197                 state = MCP2120_STATE_WAIT1_RESET;
 198                 delay = 50;
 199                 break;
 200
 201         case MCP2120_STATE_WAIT1_RESET:
 202                 //printk("mcp2120_reset: mcp2120_wait1\n");
 203                 /* clear RTS and wait for at least 30 ms. */
 204                 sirdev_set_dtr_rts(dev, FALSE, FALSE);
 205                 state = MCP2120_STATE_WAIT2_RESET;
 206                 delay = 50;
 207                 break;
 208
 209         case MCP2120_STATE_WAIT2_RESET:
 210                 //printk("mcp2120_reset mcp2120_wait2\n");
 211                 /* Go back to normal mode */
 212                 sirdev_set_dtr_rts(dev, FALSE, FALSE);
 213                 break;
 214
 215         default:
 216                 IRDA_ERROR("%s(), undefined state %d\n", __func__, state);
 217                 ret = -EINVAL;
 218                 break;
 219         }
 220         dev->fsm.substate = state;
 221         return (delay > 0) ? delay : ret;
 222 }
 223
 224 MODULE_AUTHOR("Felix Tang <tangf@eyetap.org>");
 225 MODULE_DESCRIPTION("Microchip MCP2120");
 226 MODULE_LICENSE("GPL");
 227 MODULE_ALIAS("irda-dongle-9"); /* IRDA_MCP2120_DONGLE */
 228
 229 module_init(mcp2120_sir_init);
 230 module_exit(mcp2120_sir_cleanup);