1 /*
2  *  Copyright (c) 2000-2001 Vojtech Pavlik <vojtech@ucw.cz>
3  *  Copyright (c) 2001, 2007 Johann Deneux <johann.deneux@gmail.com>
4  *
5  *  USB/RS232 I-Force joysticks and wheels.
6  */
7 
8 /*
9  * This program is free software; you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License as published by
11  * the Free Software Foundation; either version 2 of the License, or
12  * (at your option) any later version.
13  *
14  * This program is distributed in the hope that it will be useful,
15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17  * GNU General Public License for more details.
18  *
19  * You should have received a copy of the GNU General Public License
20  * along with this program; if not, write to the Free Software
21  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
22  *
23  * Should you need to contact me, the author, you can do so either by
24  * e-mail - mail your message to <vojtech@ucw.cz>, or by paper mail:
25  * Vojtech Pavlik, Simunkova 1594, Prague 8, 182 00 Czech Republic
26  */
27 
28 #include "iforce.h"
29 
30 void iforce_serial_xmit(struct iforce *iforce)
31 {
32 	unsigned char cs;
33 	int i;
34 	unsigned long flags;
35 
36 	if (test_and_set_bit(IFORCE_XMIT_RUNNING, iforce->xmit_flags)) {
37 		set_bit(IFORCE_XMIT_AGAIN, iforce->xmit_flags);
38 		return;
39 	}
40 
41 	spin_lock_irqsave(&iforce->xmit_lock, flags);
42 
43 again:
44 	if (iforce->xmit.head == iforce->xmit.tail) {
45 		clear_bit(IFORCE_XMIT_RUNNING, iforce->xmit_flags);
46 		spin_unlock_irqrestore(&iforce->xmit_lock, flags);
47 		return;
48 	}
49 
50 	cs = 0x2b;
51 
52 	serio_write(iforce->serio, 0x2b);
53 
54 	serio_write(iforce->serio, iforce->xmit.buf[iforce->xmit.tail]);
55 	cs ^= iforce->xmit.buf[iforce->xmit.tail];
56 	XMIT_INC(iforce->xmit.tail, 1);
57 
58 	for (i=iforce->xmit.buf[iforce->xmit.tail]; i >= 0; --i) {
59 		serio_write(iforce->serio, iforce->xmit.buf[iforce->xmit.tail]);
60 		cs ^= iforce->xmit.buf[iforce->xmit.tail];
61 		XMIT_INC(iforce->xmit.tail, 1);
62 	}
63 
64 	serio_write(iforce->serio, cs);
65 
66 	if (test_and_clear_bit(IFORCE_XMIT_AGAIN, iforce->xmit_flags))
67 		goto again;
68 
69 	clear_bit(IFORCE_XMIT_RUNNING, iforce->xmit_flags);
70 
71 	spin_unlock_irqrestore(&iforce->xmit_lock, flags);
72 }
73 
74 static void iforce_serio_write_wakeup(struct serio *serio)
75 {
76 	struct iforce *iforce = serio_get_drvdata(serio);
77 
78 	iforce_serial_xmit(iforce);
79 }
80 
81 static irqreturn_t iforce_serio_irq(struct serio *serio,
82 		unsigned char data, unsigned int flags)
83 {
84 	struct iforce *iforce = serio_get_drvdata(serio);
85 
86 	if (!iforce->pkt) {
87 		if (data == 0x2b)
88 			iforce->pkt = 1;
89 		goto out;
90 	}
91 
92 	if (!iforce->id) {
93 		if (data > 3 && data != 0xff)
94 			iforce->pkt = 0;
95 		else
96 			iforce->id = data;
97 		goto out;
98 	}
99 
100 	if (!iforce->len) {
101 		if (data > IFORCE_MAX_LENGTH) {
102 			iforce->pkt = 0;
103 			iforce->id = 0;
104 		} else {
105 			iforce->len = data;
106 		}
107 		goto out;
108 	}
109 
110 	if (iforce->idx < iforce->len) {
111 		iforce->csum += iforce->data[iforce->idx++] = data;
112 		goto out;
113 	}
114 
115 	if (iforce->idx == iforce->len) {
116 		iforce_process_packet(iforce, (iforce->id << 8) | iforce->idx, iforce->data);
117 		iforce->pkt = 0;
118 		iforce->id  = 0;
119 		iforce->len = 0;
120 		iforce->idx = 0;
121 		iforce->csum = 0;
122 	}
123 out:
124 	return IRQ_HANDLED;
125 }
126 
127 static int iforce_serio_connect(struct serio *serio, struct serio_driver *drv)
128 {
129 	struct iforce *iforce;
130 	int err;
131 
132 	iforce = kzalloc(sizeof(struct iforce), GFP_KERNEL);
133 	if (!iforce)
134 		return -ENOMEM;
135 
136 	iforce->bus = IFORCE_232;
137 	iforce->serio = serio;
138 
139 	serio_set_drvdata(serio, iforce);
140 
141 	err = serio_open(serio, drv);
142 	if (err)
143 		goto fail1;
144 
145 	err = iforce_init_device(iforce);
146 	if (err)
147 		goto fail2;
148 
149 	return 0;
150 
151  fail2:	serio_close(serio);
152  fail1:	serio_set_drvdata(serio, NULL);
153 	kfree(iforce);
154 	return err;
155 }
156 
157 static void iforce_serio_disconnect(struct serio *serio)
158 {
159 	struct iforce *iforce = serio_get_drvdata(serio);
160 
161 	input_unregister_device(iforce->dev);
162 	serio_close(serio);
163 	serio_set_drvdata(serio, NULL);
164 	kfree(iforce);
165 }
166 
167 static struct serio_device_id iforce_serio_ids[] = {
168 	{
169 		.type	= SERIO_RS232,
170 		.proto	= SERIO_IFORCE,
171 		.id	= SERIO_ANY,
172 		.extra	= SERIO_ANY,
173 	},
174 	{ 0 }
175 };
176 
177 MODULE_DEVICE_TABLE(serio, iforce_serio_ids);
178 
179 struct serio_driver iforce_serio_drv = {
180 	.driver		= {
181 		.name	= "iforce",
182 	},
183 	.description	= "RS232 I-Force joysticks and wheels driver",
184 	.id_table	= iforce_serio_ids,
185 	.write_wakeup	= iforce_serio_write_wakeup,
186 	.interrupt	= iforce_serio_irq,
187 	.connect	= iforce_serio_connect,
188 	.disconnect	= iforce_serio_disconnect,
189 };
190