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