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         /* 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
  75 static 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
  94 static 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
 179 static 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
 218 MODULE_AUTHOR("Felix Tang <tangf@eyetap.org>");
 219 MODULE_DESCRIPTION("Microchip MCP2120");
 220 MODULE_LICENSE("GPL");
 221 MODULE_ALIAS("irda-dongle-9"); /* IRDA_MCP2120_DONGLE */
 222
 223 module_init(mcp2120_sir_init);
 224 module_exit(mcp2120_sir_cleanup);