1 /*
2  * $Id: iforce-serio.c,v 1.4 2002/01/28 22:45:00 jdeneux Exp $
3  *
4  *  Copyright (c) 2000-2001 Vojtech Pavlik <vojtech@ucw.cz>
5  *  Copyright (c) 2001 Johann Deneux <deneux@ifrance.com>
6  *
7  *  USB/RS232 I-Force joysticks and wheels.
8  */
9 
10 /*
11  * This program is free software; you can redistribute it and/or modify
12  * it under the terms of the GNU General Public License as published by
13  * the Free Software Foundation; either version 2 of the License, or
14  * (at your option) any later version.
15  *
16  * This program is distributed in the hope that it will be useful,
17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
19  * GNU General Public License for more details.
20  *
21  * You should have received a copy of the GNU General Public License
22  * along with this program; if not, write to the Free Software
23  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
24  *
25  * Should you need to contact me, the author, you can do so either by
26  * e-mail - mail your message to <vojtech@ucw.cz>, or by paper mail:
27  * Vojtech Pavlik, Simunkova 1594, Prague 8, 182 00 Czech Republic
28  */
29 
30 #include "iforce.h"
31 
32 void iforce_serial_xmit(struct iforce *iforce)
33 {
34 	unsigned char cs;
35 	int i;
36 	unsigned long flags;
37 
38 	if (test_and_set_bit(IFORCE_XMIT_RUNNING, iforce->xmit_flags)) {
39 		set_bit(IFORCE_XMIT_AGAIN, iforce->xmit_flags);
40 		return;
41 	}
42 
43 	spin_lock_irqsave(&iforce->xmit_lock, flags);
44 
45 again:
46 	if (iforce->xmit.head == iforce->xmit.tail) {
47 		clear_bit(IFORCE_XMIT_RUNNING, iforce->xmit_flags);
48 		spin_unlock_irqrestore(&iforce->xmit_lock, flags);
49 		return;
50 	}
51 
52 	cs = 0x2b;
53 
54 	serio_write(iforce->serio, 0x2b);
55 
56 	serio_write(iforce->serio, iforce->xmit.buf[iforce->xmit.tail]);
57 	cs ^= iforce->xmit.buf[iforce->xmit.tail];
58 	XMIT_INC(iforce->xmit.tail, 1);
59 
60 	for (i=iforce->xmit.buf[iforce->xmit.tail]; i >= 0; --i) {
61 		serio_write(iforce->serio, iforce->xmit.buf[iforce->xmit.tail]);
62 		cs ^= iforce->xmit.buf[iforce->xmit.tail];
63 		XMIT_INC(iforce->xmit.tail, 1);
64 	}
65 
66 	serio_write(iforce->serio, cs);
67 
68 	if (test_and_clear_bit(IFORCE_XMIT_AGAIN, iforce->xmit_flags))
69 		goto again;
70 
71 	clear_bit(IFORCE_XMIT_RUNNING, iforce->xmit_flags);
72 
73 	spin_unlock_irqrestore(&iforce->xmit_lock, flags);
74 }
75 
76 static void iforce_serio_write_wakeup(struct serio *serio)
77 {
78 	struct iforce *iforce = serio_get_drvdata(serio);
79 
80 	iforce_serial_xmit(iforce);
81 }
82 
83 static irqreturn_t iforce_serio_irq(struct serio *serio,
84 		unsigned char data, unsigned int flags, struct pt_regs *regs)
85 {
86 	struct iforce *iforce = serio_get_drvdata(serio);
87 
88 	if (!iforce->pkt) {
89 		if (data == 0x2b)
90 			iforce->pkt = 1;
91 		goto out;
92 	}
93 
94 	if (!iforce->id) {
95 		if (data > 3 && data != 0xff)
96 			iforce->pkt = 0;
97 		else
98 			iforce->id = data;
99 		goto out;
100 	}
101 
102 	if (!iforce->len) {
103 		if (data > IFORCE_MAX_LENGTH) {
104 			iforce->pkt = 0;
105 			iforce->id = 0;
106 		} else {
107 			iforce->len = data;
108 		}
109 		goto out;
110 	}
111 
112 	if (iforce->idx < iforce->len) {
113 		iforce->csum += iforce->data[iforce->idx++] = data;
114 		goto out;
115 	}
116 
117 	if (iforce->idx == iforce->len) {
118 		iforce_process_packet(iforce, (iforce->id << 8) | iforce->idx, iforce->data, regs);
119 		iforce->pkt = 0;
120 		iforce->id  = 0;
121 		iforce->len = 0;
122 		iforce->idx = 0;
123 		iforce->csum = 0;
124 	}
125 out:
126 	return IRQ_HANDLED;
127 }
128 
129 static int iforce_serio_connect(struct serio *serio, struct serio_driver *drv)
130 {
131 	struct iforce *iforce;
132 	int err;
133 
134 	if (!(iforce = kmalloc(sizeof(struct iforce), GFP_KERNEL)))
135 		return -ENOMEM;
136 
137 	memset(iforce, 0, sizeof(struct iforce));
138 
139 	iforce->bus = IFORCE_232;
140 	iforce->serio = serio;
141 
142 	serio_set_drvdata(serio, iforce);
143 
144 	err = serio_open(serio, drv);
145 	if (err) {
146 		serio_set_drvdata(serio, NULL);
147 		kfree(iforce);
148 		return err;
149 	}
150 
151 	if (iforce_init_device(iforce)) {
152 		serio_close(serio);
153 		serio_set_drvdata(serio, NULL);
154 		kfree(iforce);
155 		return -ENODEV;
156 	}
157 
158 	return 0;
159 }
160 
161 static void iforce_serio_disconnect(struct serio *serio)
162 {
163 	struct iforce *iforce = serio_get_drvdata(serio);
164 
165 	input_unregister_device(&iforce->dev);
166 	serio_close(serio);
167 	serio_set_drvdata(serio, NULL);
168 	kfree(iforce);
169 }
170 
171 static struct serio_device_id iforce_serio_ids[] = {
172 	{
173 		.type	= SERIO_RS232,
174 		.proto	= SERIO_IFORCE,
175 		.id	= SERIO_ANY,
176 		.extra	= SERIO_ANY,
177 	},
178 	{ 0 }
179 };
180 
181 MODULE_DEVICE_TABLE(serio, iforce_serio_ids);
182 
183 struct serio_driver iforce_serio_drv = {
184 	.driver		= {
185 		.name	= "iforce",
186 	},
187 	.description	= "RS232 I-Force joysticks and wheels driver",
188 	.id_table	= iforce_serio_ids,
189 	.write_wakeup	= iforce_serio_write_wakeup,
190 	.interrupt	= iforce_serio_irq,
191 	.connect	= iforce_serio_connect,
192 	.disconnect	= iforce_serio_disconnect,
193 };
194