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
mcp2120_sir_init(void)52 static int __init mcp2120_sir_init(void)
53 {
54 return irda_register_dongle(&mcp2120);
55 }
56
mcp2120_sir_cleanup(void)57 static void __exit mcp2120_sir_cleanup(void)
58 {
59 irda_unregister_dongle(&mcp2120);
60 }
61
mcp2120_open(struct sir_dev * dev)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
mcp2120_close(struct sir_dev * dev)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
mcp2120_change_speed(struct sir_dev * dev,unsigned speed)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
mcp2120_reset(struct sir_dev * dev)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);
225