1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *  Copyright (c) 1999-2001 Vojtech Pavlik
4  */
5 
6 /*
7  * Magellan and Space Mouse 6dof controller driver for Linux
8  */
9 
10 #include <linux/kernel.h>
11 #include <linux/module.h>
12 #include <linux/slab.h>
13 #include <linux/input.h>
14 #include <linux/serio.h>
15 
16 #define DRIVER_DESC	"Magellan and SpaceMouse 6dof controller driver"
17 
18 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
19 MODULE_DESCRIPTION(DRIVER_DESC);
20 MODULE_LICENSE("GPL");
21 
22 /*
23  * Definitions & global arrays.
24  */
25 
26 #define	MAGELLAN_MAX_LENGTH	32
27 
28 static int magellan_buttons[] = { BTN_0, BTN_1, BTN_2, BTN_3, BTN_4, BTN_5, BTN_6, BTN_7, BTN_8 };
29 static int magellan_axes[] = { ABS_X, ABS_Y, ABS_Z, ABS_RX, ABS_RY, ABS_RZ };
30 
31 /*
32  * Per-Magellan data.
33  */
34 
35 struct magellan {
36 	struct input_dev *dev;
37 	int idx;
38 	unsigned char data[MAGELLAN_MAX_LENGTH];
39 	char phys[32];
40 };
41 
42 /*
43  * magellan_crunch_nibbles() verifies that the bytes sent from the Magellan
44  * have correct upper nibbles for the lower ones, if not, the packet will
45  * be thrown away. It also strips these upper halves to simplify further
46  * processing.
47  */
48 
magellan_crunch_nibbles(unsigned char * data,int count)49 static int magellan_crunch_nibbles(unsigned char *data, int count)
50 {
51 	static unsigned char nibbles[16] = "0AB3D56GH9:K<MN?";
52 
53 	do {
54 		if (data[count] == nibbles[data[count] & 0xf])
55 			data[count] = data[count] & 0xf;
56 		else
57 			return -1;
58 	} while (--count);
59 
60 	return 0;
61 }
62 
magellan_process_packet(struct magellan * magellan)63 static void magellan_process_packet(struct magellan* magellan)
64 {
65 	struct input_dev *dev = magellan->dev;
66 	unsigned char *data = magellan->data;
67 	int i, t;
68 
69 	if (!magellan->idx) return;
70 
71 	switch (magellan->data[0]) {
72 
73 		case 'd':				/* Axis data */
74 			if (magellan->idx != 25) return;
75 			if (magellan_crunch_nibbles(data, 24)) return;
76 			for (i = 0; i < 6; i++)
77 				input_report_abs(dev, magellan_axes[i],
78 					(data[(i << 2) + 1] << 12 | data[(i << 2) + 2] << 8 |
79 					 data[(i << 2) + 3] <<  4 | data[(i << 2) + 4]) - 32768);
80 			break;
81 
82 		case 'k':				/* Button data */
83 			if (magellan->idx != 4) return;
84 			if (magellan_crunch_nibbles(data, 3)) return;
85 			t = (data[1] << 1) | (data[2] << 5) | data[3];
86 			for (i = 0; i < 9; i++) input_report_key(dev, magellan_buttons[i], (t >> i) & 1);
87 			break;
88 	}
89 
90 	input_sync(dev);
91 }
92 
magellan_interrupt(struct serio * serio,unsigned char data,unsigned int flags)93 static irqreturn_t magellan_interrupt(struct serio *serio,
94 		unsigned char data, unsigned int flags)
95 {
96 	struct magellan* magellan = serio_get_drvdata(serio);
97 
98 	if (data == '\r') {
99 		magellan_process_packet(magellan);
100 		magellan->idx = 0;
101 	} else {
102 		if (magellan->idx < MAGELLAN_MAX_LENGTH)
103 			magellan->data[magellan->idx++] = data;
104 	}
105 	return IRQ_HANDLED;
106 }
107 
108 /*
109  * magellan_disconnect() is the opposite of magellan_connect()
110  */
111 
magellan_disconnect(struct serio * serio)112 static void magellan_disconnect(struct serio *serio)
113 {
114 	struct magellan* magellan = serio_get_drvdata(serio);
115 
116 	serio_close(serio);
117 	serio_set_drvdata(serio, NULL);
118 	input_unregister_device(magellan->dev);
119 	kfree(magellan);
120 }
121 
122 /*
123  * magellan_connect() is the routine that is called when someone adds a
124  * new serio device that supports Magellan protocol and registers it as
125  * an input device.
126  */
127 
magellan_connect(struct serio * serio,struct serio_driver * drv)128 static int magellan_connect(struct serio *serio, struct serio_driver *drv)
129 {
130 	struct magellan *magellan;
131 	struct input_dev *input_dev;
132 	int err = -ENOMEM;
133 	int i;
134 
135 	magellan = kzalloc(sizeof(struct magellan), GFP_KERNEL);
136 	input_dev = input_allocate_device();
137 	if (!magellan || !input_dev)
138 		goto fail1;
139 
140 	magellan->dev = input_dev;
141 	snprintf(magellan->phys, sizeof(magellan->phys), "%s/input0", serio->phys);
142 
143 	input_dev->name = "LogiCad3D Magellan / SpaceMouse";
144 	input_dev->phys = magellan->phys;
145 	input_dev->id.bustype = BUS_RS232;
146 	input_dev->id.vendor = SERIO_MAGELLAN;
147 	input_dev->id.product = 0x0001;
148 	input_dev->id.version = 0x0100;
149 	input_dev->dev.parent = &serio->dev;
150 
151 	input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
152 
153 	for (i = 0; i < 9; i++)
154 		set_bit(magellan_buttons[i], input_dev->keybit);
155 
156 	for (i = 0; i < 6; i++)
157 		input_set_abs_params(input_dev, magellan_axes[i], -360, 360, 0, 0);
158 
159 	serio_set_drvdata(serio, magellan);
160 
161 	err = serio_open(serio, drv);
162 	if (err)
163 		goto fail2;
164 
165 	err = input_register_device(magellan->dev);
166 	if (err)
167 		goto fail3;
168 
169 	return 0;
170 
171  fail3:	serio_close(serio);
172  fail2:	serio_set_drvdata(serio, NULL);
173  fail1:	input_free_device(input_dev);
174 	kfree(magellan);
175 	return err;
176 }
177 
178 /*
179  * The serio driver structure.
180  */
181 
182 static const struct serio_device_id magellan_serio_ids[] = {
183 	{
184 		.type	= SERIO_RS232,
185 		.proto	= SERIO_MAGELLAN,
186 		.id	= SERIO_ANY,
187 		.extra	= SERIO_ANY,
188 	},
189 	{ 0 }
190 };
191 
192 MODULE_DEVICE_TABLE(serio, magellan_serio_ids);
193 
194 static struct serio_driver magellan_drv = {
195 	.driver		= {
196 		.name	= "magellan",
197 	},
198 	.description	= DRIVER_DESC,
199 	.id_table	= magellan_serio_ids,
200 	.interrupt	= magellan_interrupt,
201 	.connect	= magellan_connect,
202 	.disconnect	= magellan_disconnect,
203 };
204 
205 module_serio_driver(magellan_drv);
206