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 /*
11  */
12 
13 #include <linux/kernel.h>
14 #include <linux/module.h>
15 #include <linux/slab.h>
16 #include <linux/input.h>
17 #include <linux/serio.h>
18 
19 #define DRIVER_DESC	"Magellan and SpaceMouse 6dof controller driver"
20 
21 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
22 MODULE_DESCRIPTION(DRIVER_DESC);
23 MODULE_LICENSE("GPL");
24 
25 /*
26  * Definitions & global arrays.
27  */
28 
29 #define	MAGELLAN_MAX_LENGTH	32
30 
31 static int magellan_buttons[] = { BTN_0, BTN_1, BTN_2, BTN_3, BTN_4, BTN_5, BTN_6, BTN_7, BTN_8 };
32 static int magellan_axes[] = { ABS_X, ABS_Y, ABS_Z, ABS_RX, ABS_RY, ABS_RZ };
33 
34 /*
35  * Per-Magellan data.
36  */
37 
38 struct magellan {
39 	struct input_dev *dev;
40 	int idx;
41 	unsigned char data[MAGELLAN_MAX_LENGTH];
42 	char phys[32];
43 };
44 
45 /*
46  * magellan_crunch_nibbles() verifies that the bytes sent from the Magellan
47  * have correct upper nibbles for the lower ones, if not, the packet will
48  * be thrown away. It also strips these upper halves to simplify further
49  * processing.
50  */
51 
52 static int magellan_crunch_nibbles(unsigned char *data, int count)
53 {
54 	static unsigned char nibbles[16] = "0AB3D56GH9:K<MN?";
55 
56 	do {
57 		if (data[count] == nibbles[data[count] & 0xf])
58 			data[count] = data[count] & 0xf;
59 		else
60 			return -1;
61 	} while (--count);
62 
63 	return 0;
64 }
65 
66 static void magellan_process_packet(struct magellan* magellan)
67 {
68 	struct input_dev *dev = magellan->dev;
69 	unsigned char *data = magellan->data;
70 	int i, t;
71 
72 	if (!magellan->idx) return;
73 
74 	switch (magellan->data[0]) {
75 
76 		case 'd':				/* Axis data */
77 			if (magellan->idx != 25) return;
78 			if (magellan_crunch_nibbles(data, 24)) return;
79 			for (i = 0; i < 6; i++)
80 				input_report_abs(dev, magellan_axes[i],
81 					(data[(i << 2) + 1] << 12 | data[(i << 2) + 2] << 8 |
82 					 data[(i << 2) + 3] <<  4 | data[(i << 2) + 4]) - 32768);
83 			break;
84 
85 		case 'k':				/* Button data */
86 			if (magellan->idx != 4) return;
87 			if (magellan_crunch_nibbles(data, 3)) return;
88 			t = (data[1] << 1) | (data[2] << 5) | data[3];
89 			for (i = 0; i < 9; i++) input_report_key(dev, magellan_buttons[i], (t >> i) & 1);
90 			break;
91 	}
92 
93 	input_sync(dev);
94 }
95 
96 static irqreturn_t magellan_interrupt(struct serio *serio,
97 		unsigned char data, unsigned int flags)
98 {
99 	struct magellan* magellan = serio_get_drvdata(serio);
100 
101 	if (data == '\r') {
102 		magellan_process_packet(magellan);
103 		magellan->idx = 0;
104 	} else {
105 		if (magellan->idx < MAGELLAN_MAX_LENGTH)
106 			magellan->data[magellan->idx++] = data;
107 	}
108 	return IRQ_HANDLED;
109 }
110 
111 /*
112  * magellan_disconnect() is the opposite of magellan_connect()
113  */
114 
115 static void magellan_disconnect(struct serio *serio)
116 {
117 	struct magellan* magellan = serio_get_drvdata(serio);
118 
119 	serio_close(serio);
120 	serio_set_drvdata(serio, NULL);
121 	input_unregister_device(magellan->dev);
122 	kfree(magellan);
123 }
124 
125 /*
126  * magellan_connect() is the routine that is called when someone adds a
127  * new serio device that supports Magellan protocol and registers it as
128  * an input device.
129  */
130 
131 static int magellan_connect(struct serio *serio, struct serio_driver *drv)
132 {
133 	struct magellan *magellan;
134 	struct input_dev *input_dev;
135 	int err = -ENOMEM;
136 	int i;
137 
138 	magellan = kzalloc(sizeof(struct magellan), GFP_KERNEL);
139 	input_dev = input_allocate_device();
140 	if (!magellan || !input_dev)
141 		goto fail1;
142 
143 	magellan->dev = input_dev;
144 	snprintf(magellan->phys, sizeof(magellan->phys), "%s/input0", serio->phys);
145 
146 	input_dev->name = "LogiCad3D Magellan / SpaceMouse";
147 	input_dev->phys = magellan->phys;
148 	input_dev->id.bustype = BUS_RS232;
149 	input_dev->id.vendor = SERIO_MAGELLAN;
150 	input_dev->id.product = 0x0001;
151 	input_dev->id.version = 0x0100;
152 	input_dev->dev.parent = &serio->dev;
153 
154 	input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
155 
156 	for (i = 0; i < 9; i++)
157 		set_bit(magellan_buttons[i], input_dev->keybit);
158 
159 	for (i = 0; i < 6; i++)
160 		input_set_abs_params(input_dev, magellan_axes[i], -360, 360, 0, 0);
161 
162 	serio_set_drvdata(serio, magellan);
163 
164 	err = serio_open(serio, drv);
165 	if (err)
166 		goto fail2;
167 
168 	err = input_register_device(magellan->dev);
169 	if (err)
170 		goto fail3;
171 
172 	return 0;
173 
174  fail3:	serio_close(serio);
175  fail2:	serio_set_drvdata(serio, NULL);
176  fail1:	input_free_device(input_dev);
177 	kfree(magellan);
178 	return err;
179 }
180 
181 /*
182  * The serio driver structure.
183  */
184 
185 static const struct serio_device_id magellan_serio_ids[] = {
186 	{
187 		.type	= SERIO_RS232,
188 		.proto	= SERIO_MAGELLAN,
189 		.id	= SERIO_ANY,
190 		.extra	= SERIO_ANY,
191 	},
192 	{ 0 }
193 };
194 
195 MODULE_DEVICE_TABLE(serio, magellan_serio_ids);
196 
197 static struct serio_driver magellan_drv = {
198 	.driver		= {
199 		.name	= "magellan",
200 	},
201 	.description	= DRIVER_DESC,
202 	.id_table	= magellan_serio_ids,
203 	.interrupt	= magellan_interrupt,
204 	.connect	= magellan_connect,
205 	.disconnect	= magellan_disconnect,
206 };
207 
208 module_serio_driver(magellan_drv);
209