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 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
mcp2120_close(struct sir_dev * dev)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
mcp2120_change_speed(struct sir_dev * dev,unsigned speed)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
mcp2120_reset(struct sir_dev * dev)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);
231