1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Copyright (c) 1999-2001 Vojtech Pavlik
4 */
5
6/*
7 * Serial mouse driver for Linux
8 */
9
10#include <linux/delay.h>
11#include <linux/module.h>
12#include <linux/slab.h>
13#include <linux/interrupt.h>
14#include <linux/input.h>
15#include <linux/serio.h>
16
17#define DRIVER_DESC "Serial mouse driver"
18
19MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
20MODULE_DESCRIPTION(DRIVER_DESC);
21MODULE_LICENSE("GPL");
22
23static const char *sermouse_protocols[] = { "None", "Mouse Systems Mouse", "Sun Mouse", "Microsoft Mouse",
24 "Logitech M+ Mouse", "Microsoft MZ Mouse", "Logitech MZ+ Mouse",
25 "Logitech MZ++ Mouse"};
26
27struct sermouse {
28 struct input_dev *dev;
29 signed char buf[8];
30 unsigned char count;
31 unsigned char type;
32 unsigned long last;
33 char phys[32];
34};
35
36/*
37 * sermouse_process_msc() analyzes the incoming MSC/Sun bytestream and
38 * applies some prediction to the data, resulting in 96 updates per
39 * second, which is as good as a PS/2 or USB mouse.
40 */
41
42static void sermouse_process_msc(struct sermouse *sermouse, signed char data)
43{
44 struct input_dev *dev = sermouse->dev;
45 signed char *buf = sermouse->buf;
46
47 switch (sermouse->count) {
48
49 case 0:
50 if ((data & 0xf8) != 0x80)
51 return;
52 input_report_key(dev, BTN_LEFT, value: !(data & 4));
53 input_report_key(dev, BTN_RIGHT, value: !(data & 1));
54 input_report_key(dev, BTN_MIDDLE, value: !(data & 2));
55 break;
56
57 case 1:
58 case 3:
59 input_report_rel(dev, REL_X, value: data / 2);
60 input_report_rel(dev, REL_Y, value: -buf[1]);
61 buf[0] = data - data / 2;
62 break;
63
64 case 2:
65 case 4:
66 input_report_rel(dev, REL_X, value: buf[0]);
67 input_report_rel(dev, REL_Y, value: buf[1] - data);
68 buf[1] = data / 2;
69 break;
70 }
71
72 input_sync(dev);
73
74 if (++sermouse->count == 5)
75 sermouse->count = 0;
76}
77
78/*
79 * sermouse_process_ms() anlyzes the incoming MS(Z/+/++) bytestream and
80 * generates events. With prediction it gets 80 updates/sec, assuming
81 * standard 3-byte packets and 1200 bps.
82 */
83
84static void sermouse_process_ms(struct sermouse *sermouse, signed char data)
85{
86 struct input_dev *dev = sermouse->dev;
87 signed char *buf = sermouse->buf;
88
89 if (data & 0x40)
90 sermouse->count = 0;
91 else if (sermouse->count == 0)
92 return;
93
94 switch (sermouse->count) {
95
96 case 0:
97 buf[1] = data;
98 input_report_key(dev, BTN_LEFT, value: (data >> 5) & 1);
99 input_report_key(dev, BTN_RIGHT, value: (data >> 4) & 1);
100 break;
101
102 case 1:
103 buf[2] = data;
104 data = (signed char) (((buf[1] << 6) & 0xc0) | (data & 0x3f));
105 input_report_rel(dev, REL_X, value: data / 2);
106 input_report_rel(dev, REL_Y, value: buf[4]);
107 buf[3] = data - data / 2;
108 break;
109
110 case 2:
111 /* Guessing the state of the middle button on 3-button MS-protocol mice - ugly. */
112 if ((sermouse->type == SERIO_MS) && !data && !buf[2] && !((buf[0] & 0xf0) ^ buf[1]))
113 input_report_key(dev, BTN_MIDDLE, value: !test_bit(BTN_MIDDLE, dev->key));
114 buf[0] = buf[1];
115
116 data = (signed char) (((buf[1] << 4) & 0xc0) | (data & 0x3f));
117 input_report_rel(dev, REL_X, value: buf[3]);
118 input_report_rel(dev, REL_Y, value: data - buf[4]);
119 buf[4] = data / 2;
120 break;
121
122 case 3:
123
124 switch (sermouse->type) {
125
126 case SERIO_MS:
127 sermouse->type = SERIO_MP;
128 fallthrough;
129
130 case SERIO_MP:
131 if ((data >> 2) & 3) break; /* M++ Wireless Extension packet. */
132 input_report_key(dev, BTN_MIDDLE, value: (data >> 5) & 1);
133 input_report_key(dev, BTN_SIDE, value: (data >> 4) & 1);
134 break;
135
136 case SERIO_MZP:
137 case SERIO_MZPP:
138 input_report_key(dev, BTN_SIDE, value: (data >> 5) & 1);
139 fallthrough;
140
141 case SERIO_MZ:
142 input_report_key(dev, BTN_MIDDLE, value: (data >> 4) & 1);
143 input_report_rel(dev, REL_WHEEL, value: (data & 8) - (data & 7));
144 break;
145 }
146
147 break;
148
149 case 4:
150 case 6: /* MZ++ packet type. We can get these bytes for M++ too but we ignore them later. */
151 buf[1] = (data >> 2) & 0x0f;
152 break;
153
154 case 5:
155 case 7: /* Ignore anything besides MZ++ */
156 if (sermouse->type != SERIO_MZPP)
157 break;
158
159 switch (buf[1]) {
160
161 case 1: /* Extra mouse info */
162
163 input_report_key(dev, BTN_SIDE, value: (data >> 4) & 1);
164 input_report_key(dev, BTN_EXTRA, value: (data >> 5) & 1);
165 input_report_rel(dev, code: data & 0x80 ? REL_HWHEEL : REL_WHEEL, value: (data & 7) - (data & 8));
166
167 break;
168
169 default: /* We don't decode anything else yet. */
170
171 printk(KERN_WARNING
172 "sermouse.c: Received MZ++ packet %x, don't know how to handle.\n", buf[1]);
173 break;
174 }
175
176 break;
177 }
178
179 input_sync(dev);
180
181 sermouse->count++;
182}
183
184/*
185 * sermouse_interrupt() handles incoming characters, either gathering them into
186 * packets or passing them to the command routine as command output.
187 */
188
189static irqreturn_t sermouse_interrupt(struct serio *serio,
190 unsigned char data, unsigned int flags)
191{
192 struct sermouse *sermouse = serio_get_drvdata(serio);
193
194 if (time_after(jiffies, sermouse->last + HZ/10))
195 sermouse->count = 0;
196
197 sermouse->last = jiffies;
198
199 if (sermouse->type > SERIO_SUN)
200 sermouse_process_ms(sermouse, data);
201 else
202 sermouse_process_msc(sermouse, data);
203
204 return IRQ_HANDLED;
205}
206
207/*
208 * sermouse_disconnect() cleans up after we don't want talk
209 * to the mouse anymore.
210 */
211
212static void sermouse_disconnect(struct serio *serio)
213{
214 struct sermouse *sermouse = serio_get_drvdata(serio);
215
216 serio_close(serio);
217 serio_set_drvdata(serio, NULL);
218 input_unregister_device(sermouse->dev);
219 kfree(objp: sermouse);
220}
221
222/*
223 * sermouse_connect() is a callback form the serio module when
224 * an unhandled serio port is found.
225 */
226
227static int sermouse_connect(struct serio *serio, struct serio_driver *drv)
228{
229 struct sermouse *sermouse;
230 struct input_dev *input_dev;
231 unsigned char c = serio->id.extra;
232 int err = -ENOMEM;
233
234 sermouse = kzalloc(size: sizeof(struct sermouse), GFP_KERNEL);
235 input_dev = input_allocate_device();
236 if (!sermouse || !input_dev)
237 goto fail1;
238
239 sermouse->dev = input_dev;
240 snprintf(buf: sermouse->phys, size: sizeof(sermouse->phys), fmt: "%s/input0", serio->phys);
241 sermouse->type = serio->id.proto;
242
243 input_dev->name = sermouse_protocols[sermouse->type];
244 input_dev->phys = sermouse->phys;
245 input_dev->id.bustype = BUS_RS232;
246 input_dev->id.vendor = sermouse->type;
247 input_dev->id.product = c;
248 input_dev->id.version = 0x0100;
249 input_dev->dev.parent = &serio->dev;
250
251 input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_REL);
252 input_dev->keybit[BIT_WORD(BTN_MOUSE)] = BIT_MASK(BTN_LEFT) |
253 BIT_MASK(BTN_RIGHT);
254 input_dev->relbit[0] = BIT_MASK(REL_X) | BIT_MASK(REL_Y);
255
256 if (c & 0x01) set_bit(BTN_MIDDLE, addr: input_dev->keybit);
257 if (c & 0x02) set_bit(BTN_SIDE, addr: input_dev->keybit);
258 if (c & 0x04) set_bit(BTN_EXTRA, addr: input_dev->keybit);
259 if (c & 0x10) set_bit(REL_WHEEL, addr: input_dev->relbit);
260 if (c & 0x20) set_bit(REL_HWHEEL, addr: input_dev->relbit);
261
262 serio_set_drvdata(serio, data: sermouse);
263
264 err = serio_open(serio, drv);
265 if (err)
266 goto fail2;
267
268 err = input_register_device(sermouse->dev);
269 if (err)
270 goto fail3;
271
272 return 0;
273
274 fail3: serio_close(serio);
275 fail2: serio_set_drvdata(serio, NULL);
276 fail1: input_free_device(dev: input_dev);
277 kfree(objp: sermouse);
278 return err;
279}
280
281static struct serio_device_id sermouse_serio_ids[] = {
282 {
283 .type = SERIO_RS232,
284 .proto = SERIO_MSC,
285 .id = SERIO_ANY,
286 .extra = SERIO_ANY,
287 },
288 {
289 .type = SERIO_RS232,
290 .proto = SERIO_SUN,
291 .id = SERIO_ANY,
292 .extra = SERIO_ANY,
293 },
294 {
295 .type = SERIO_RS232,
296 .proto = SERIO_MS,
297 .id = SERIO_ANY,
298 .extra = SERIO_ANY,
299 },
300 {
301 .type = SERIO_RS232,
302 .proto = SERIO_MP,
303 .id = SERIO_ANY,
304 .extra = SERIO_ANY,
305 },
306 {
307 .type = SERIO_RS232,
308 .proto = SERIO_MZ,
309 .id = SERIO_ANY,
310 .extra = SERIO_ANY,
311 },
312 {
313 .type = SERIO_RS232,
314 .proto = SERIO_MZP,
315 .id = SERIO_ANY,
316 .extra = SERIO_ANY,
317 },
318 {
319 .type = SERIO_RS232,
320 .proto = SERIO_MZPP,
321 .id = SERIO_ANY,
322 .extra = SERIO_ANY,
323 },
324 { 0 }
325};
326
327MODULE_DEVICE_TABLE(serio, sermouse_serio_ids);
328
329static struct serio_driver sermouse_drv = {
330 .driver = {
331 .name = "sermouse",
332 },
333 .description = DRIVER_DESC,
334 .id_table = sermouse_serio_ids,
335 .interrupt = sermouse_interrupt,
336 .connect = sermouse_connect,
337 .disconnect = sermouse_disconnect,
338};
339
340module_serio_driver(sermouse_drv);
341

source code of linux/drivers/input/mouse/sermouse.c