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