1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright (c) 2000-2001 Vojtech Pavlik <vojtech@ucw.cz>
4 * Copyright (c) 2001, 2007 Johann Deneux <johann.deneux@gmail.com>
5 *
6 * USB/RS232 I-Force joysticks and wheels.
7 */
8
9 #include <linux/serio.h>
10 #include "iforce.h"
11
12 struct iforce_serio {
13 struct iforce iforce;
14
15 struct serio *serio;
16 int idx, pkt, len, id;
17 u8 csum;
18 u8 expect_packet;
19 u8 cmd_response[IFORCE_MAX_LENGTH];
20 u8 cmd_response_len;
21 u8 data_in[IFORCE_MAX_LENGTH];
22 };
23
iforce_serio_xmit(struct iforce * iforce)24 static void iforce_serio_xmit(struct iforce *iforce)
25 {
26 struct iforce_serio *iforce_serio = container_of(iforce,
27 struct iforce_serio,
28 iforce);
29 unsigned char cs;
30 int i;
31 unsigned long flags;
32
33 if (test_and_set_bit(IFORCE_XMIT_RUNNING, iforce->xmit_flags)) {
34 set_bit(IFORCE_XMIT_AGAIN, iforce->xmit_flags);
35 return;
36 }
37
38 spin_lock_irqsave(&iforce->xmit_lock, flags);
39
40 again:
41 if (iforce->xmit.head == iforce->xmit.tail) {
42 iforce_clear_xmit_and_wake(iforce);
43 spin_unlock_irqrestore(&iforce->xmit_lock, flags);
44 return;
45 }
46
47 cs = 0x2b;
48
49 serio_write(iforce_serio->serio, 0x2b);
50
51 serio_write(iforce_serio->serio, iforce->xmit.buf[iforce->xmit.tail]);
52 cs ^= iforce->xmit.buf[iforce->xmit.tail];
53 XMIT_INC(iforce->xmit.tail, 1);
54
55 for (i=iforce->xmit.buf[iforce->xmit.tail]; i >= 0; --i) {
56 serio_write(iforce_serio->serio,
57 iforce->xmit.buf[iforce->xmit.tail]);
58 cs ^= iforce->xmit.buf[iforce->xmit.tail];
59 XMIT_INC(iforce->xmit.tail, 1);
60 }
61
62 serio_write(iforce_serio->serio, cs);
63
64 if (test_and_clear_bit(IFORCE_XMIT_AGAIN, iforce->xmit_flags))
65 goto again;
66
67 iforce_clear_xmit_and_wake(iforce);
68
69 spin_unlock_irqrestore(&iforce->xmit_lock, flags);
70 }
71
iforce_serio_get_id(struct iforce * iforce,u8 id,u8 * response_data,size_t * response_len)72 static int iforce_serio_get_id(struct iforce *iforce, u8 id,
73 u8 *response_data, size_t *response_len)
74 {
75 struct iforce_serio *iforce_serio = container_of(iforce,
76 struct iforce_serio,
77 iforce);
78
79 iforce_serio->expect_packet = HI(FF_CMD_QUERY);
80 iforce_serio->cmd_response_len = 0;
81
82 iforce_send_packet(iforce, FF_CMD_QUERY, &id);
83
84 wait_event_interruptible_timeout(iforce->wait,
85 !iforce_serio->expect_packet, HZ);
86
87 if (iforce_serio->expect_packet) {
88 iforce_serio->expect_packet = 0;
89 return -ETIMEDOUT;
90 }
91
92 if (iforce_serio->cmd_response[0] != id)
93 return -EIO;
94
95 memcpy(response_data, iforce_serio->cmd_response,
96 iforce_serio->cmd_response_len);
97 *response_len = iforce_serio->cmd_response_len;
98
99 return 0;
100 }
101
iforce_serio_start_io(struct iforce * iforce)102 static int iforce_serio_start_io(struct iforce *iforce)
103 {
104 /* No special handling required */
105 return 0;
106 }
107
iforce_serio_stop_io(struct iforce * iforce)108 static void iforce_serio_stop_io(struct iforce *iforce)
109 {
110 //TODO: Wait for the last packets to be sent
111 }
112
113 static const struct iforce_xport_ops iforce_serio_xport_ops = {
114 .xmit = iforce_serio_xmit,
115 .get_id = iforce_serio_get_id,
116 .start_io = iforce_serio_start_io,
117 .stop_io = iforce_serio_stop_io,
118 };
119
iforce_serio_write_wakeup(struct serio * serio)120 static void iforce_serio_write_wakeup(struct serio *serio)
121 {
122 struct iforce *iforce = serio_get_drvdata(serio);
123
124 iforce_serio_xmit(iforce);
125 }
126
iforce_serio_irq(struct serio * serio,unsigned char data,unsigned int flags)127 static irqreturn_t iforce_serio_irq(struct serio *serio,
128 unsigned char data, unsigned int flags)
129 {
130 struct iforce_serio *iforce_serio = serio_get_drvdata(serio);
131 struct iforce *iforce = &iforce_serio->iforce;
132
133 if (!iforce_serio->pkt) {
134 if (data == 0x2b)
135 iforce_serio->pkt = 1;
136 goto out;
137 }
138
139 if (!iforce_serio->id) {
140 if (data > 3 && data != 0xff)
141 iforce_serio->pkt = 0;
142 else
143 iforce_serio->id = data;
144 goto out;
145 }
146
147 if (!iforce_serio->len) {
148 if (data > IFORCE_MAX_LENGTH) {
149 iforce_serio->pkt = 0;
150 iforce_serio->id = 0;
151 } else {
152 iforce_serio->len = data;
153 }
154 goto out;
155 }
156
157 if (iforce_serio->idx < iforce_serio->len) {
158 iforce_serio->data_in[iforce_serio->idx++] = data;
159 iforce_serio->csum += data;
160 goto out;
161 }
162
163 if (iforce_serio->idx == iforce_serio->len) {
164 /* Handle command completion */
165 if (iforce_serio->expect_packet == iforce_serio->id) {
166 iforce_serio->expect_packet = 0;
167 memcpy(iforce_serio->cmd_response,
168 iforce_serio->data_in, IFORCE_MAX_LENGTH);
169 iforce_serio->cmd_response_len = iforce_serio->len;
170
171 /* Signal that command is done */
172 wake_up_all(&iforce->wait);
173 } else if (likely(iforce->type)) {
174 iforce_process_packet(iforce, iforce_serio->id,
175 iforce_serio->data_in,
176 iforce_serio->len);
177 }
178
179 iforce_serio->pkt = 0;
180 iforce_serio->id = 0;
181 iforce_serio->len = 0;
182 iforce_serio->idx = 0;
183 iforce_serio->csum = 0;
184 }
185 out:
186 return IRQ_HANDLED;
187 }
188
iforce_serio_connect(struct serio * serio,struct serio_driver * drv)189 static int iforce_serio_connect(struct serio *serio, struct serio_driver *drv)
190 {
191 struct iforce_serio *iforce_serio;
192 int err;
193
194 iforce_serio = kzalloc(sizeof(*iforce_serio), GFP_KERNEL);
195 if (!iforce_serio)
196 return -ENOMEM;
197
198 iforce_serio->iforce.xport_ops = &iforce_serio_xport_ops;
199
200 iforce_serio->serio = serio;
201 serio_set_drvdata(serio, iforce_serio);
202
203 err = serio_open(serio, drv);
204 if (err)
205 goto fail1;
206
207 err = iforce_init_device(&serio->dev, BUS_RS232, &iforce_serio->iforce);
208 if (err)
209 goto fail2;
210
211 return 0;
212
213 fail2: serio_close(serio);
214 fail1: serio_set_drvdata(serio, NULL);
215 kfree(iforce_serio);
216 return err;
217 }
218
iforce_serio_disconnect(struct serio * serio)219 static void iforce_serio_disconnect(struct serio *serio)
220 {
221 struct iforce_serio *iforce_serio = serio_get_drvdata(serio);
222
223 input_unregister_device(iforce_serio->iforce.dev);
224 serio_close(serio);
225 serio_set_drvdata(serio, NULL);
226 kfree(iforce_serio);
227 }
228
229 static const struct serio_device_id iforce_serio_ids[] = {
230 {
231 .type = SERIO_RS232,
232 .proto = SERIO_IFORCE,
233 .id = SERIO_ANY,
234 .extra = SERIO_ANY,
235 },
236 { 0 }
237 };
238
239 MODULE_DEVICE_TABLE(serio, iforce_serio_ids);
240
241 struct serio_driver iforce_serio_drv = {
242 .driver = {
243 .name = "iforce",
244 },
245 .description = "RS232 I-Force joysticks and wheels driver",
246 .id_table = iforce_serio_ids,
247 .write_wakeup = iforce_serio_write_wakeup,
248 .interrupt = iforce_serio_irq,
249 .connect = iforce_serio_connect,
250 .disconnect = iforce_serio_disconnect,
251 };
252
253 module_serio_driver(iforce_serio_drv);
254
255 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>, Johann Deneux <johann.deneux@gmail.com>");
256 MODULE_DESCRIPTION("RS232 I-Force joysticks and wheels driver");
257 MODULE_LICENSE("GPL");
258