1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *  Copyright (c) 2000-2001 Vojtech Pavlik
4  *  Copyright (c) 2000 Mark Fletcher
5  */
6 
7 /*
8  * Gravis Stinger gamepad driver for Linux
9  */
10 
11 /*
12  */
13 
14 #include <linux/kernel.h>
15 #include <linux/module.h>
16 #include <linux/slab.h>
17 #include <linux/input.h>
18 #include <linux/serio.h>
19 
20 #define DRIVER_DESC	"Gravis Stinger gamepad driver"
21 
22 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
23 MODULE_DESCRIPTION(DRIVER_DESC);
24 MODULE_LICENSE("GPL");
25 
26 /*
27  * Constants.
28  */
29 
30 #define STINGER_MAX_LENGTH 8
31 
32 /*
33  * Per-Stinger data.
34  */
35 
36 struct stinger {
37 	struct input_dev *dev;
38 	int idx;
39 	unsigned char data[STINGER_MAX_LENGTH];
40 	char phys[32];
41 };
42 
43 /*
44  * stinger_process_packet() decodes packets the driver receives from the
45  * Stinger. It updates the data accordingly.
46  */
47 
stinger_process_packet(struct stinger * stinger)48 static void stinger_process_packet(struct stinger *stinger)
49 {
50 	struct input_dev *dev = stinger->dev;
51 	unsigned char *data = stinger->data;
52 
53 	if (!stinger->idx) return;
54 
55 	input_report_key(dev, BTN_A,	  ((data[0] & 0x20) >> 5));
56 	input_report_key(dev, BTN_B,	  ((data[0] & 0x10) >> 4));
57 	input_report_key(dev, BTN_C,	  ((data[0] & 0x08) >> 3));
58 	input_report_key(dev, BTN_X,	  ((data[0] & 0x04) >> 2));
59 	input_report_key(dev, BTN_Y,	  ((data[3] & 0x20) >> 5));
60 	input_report_key(dev, BTN_Z,	  ((data[3] & 0x10) >> 4));
61 	input_report_key(dev, BTN_TL,     ((data[3] & 0x08) >> 3));
62 	input_report_key(dev, BTN_TR,     ((data[3] & 0x04) >> 2));
63 	input_report_key(dev, BTN_SELECT, ((data[3] & 0x02) >> 1));
64 	input_report_key(dev, BTN_START,   (data[3] & 0x01));
65 
66 	input_report_abs(dev, ABS_X, (data[1] & 0x3F) - ((data[0] & 0x01) << 6));
67 	input_report_abs(dev, ABS_Y, ((data[0] & 0x02) << 5) - (data[2] & 0x3F));
68 
69 	input_sync(dev);
70 
71 	return;
72 }
73 
74 /*
75  * stinger_interrupt() is called by the low level driver when characters
76  * are ready for us. We then buffer them for further processing, or call the
77  * packet processing routine.
78  */
79 
stinger_interrupt(struct serio * serio,unsigned char data,unsigned int flags)80 static irqreturn_t stinger_interrupt(struct serio *serio,
81 	unsigned char data, unsigned int flags)
82 {
83 	struct stinger *stinger = serio_get_drvdata(serio);
84 
85 	/* All Stinger packets are 4 bytes */
86 
87 	if (stinger->idx < STINGER_MAX_LENGTH)
88 		stinger->data[stinger->idx++] = data;
89 
90 	if (stinger->idx == 4) {
91 		stinger_process_packet(stinger);
92 		stinger->idx = 0;
93 	}
94 
95 	return IRQ_HANDLED;
96 }
97 
98 /*
99  * stinger_disconnect() is the opposite of stinger_connect()
100  */
101 
stinger_disconnect(struct serio * serio)102 static void stinger_disconnect(struct serio *serio)
103 {
104 	struct stinger *stinger = serio_get_drvdata(serio);
105 
106 	serio_close(serio);
107 	serio_set_drvdata(serio, NULL);
108 	input_unregister_device(stinger->dev);
109 	kfree(stinger);
110 }
111 
112 /*
113  * stinger_connect() is the routine that is called when someone adds a
114  * new serio device that supports Stinger protocol and registers it as
115  * an input device.
116  */
117 
stinger_connect(struct serio * serio,struct serio_driver * drv)118 static int stinger_connect(struct serio *serio, struct serio_driver *drv)
119 {
120 	struct stinger *stinger;
121 	struct input_dev *input_dev;
122 	int err = -ENOMEM;
123 
124 	stinger = kmalloc(sizeof(struct stinger), GFP_KERNEL);
125 	input_dev = input_allocate_device();
126 	if (!stinger || !input_dev)
127 		goto fail1;
128 
129 	stinger->dev = input_dev;
130 	snprintf(stinger->phys, sizeof(stinger->phys), "%s/serio0", serio->phys);
131 
132 	input_dev->name = "Gravis Stinger";
133 	input_dev->phys = stinger->phys;
134 	input_dev->id.bustype = BUS_RS232;
135 	input_dev->id.vendor = SERIO_STINGER;
136 	input_dev->id.product = 0x0001;
137 	input_dev->id.version = 0x0100;
138 	input_dev->dev.parent = &serio->dev;
139 
140 	input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
141 	input_dev->keybit[BIT_WORD(BTN_A)] = BIT_MASK(BTN_A) | BIT_MASK(BTN_B) |
142 		BIT_MASK(BTN_C) | BIT_MASK(BTN_X) | BIT_MASK(BTN_Y) |
143 		BIT_MASK(BTN_Z) | BIT_MASK(BTN_TL) | BIT_MASK(BTN_TR) |
144 		BIT_MASK(BTN_START) | BIT_MASK(BTN_SELECT);
145 	input_set_abs_params(input_dev, ABS_X, -64, 64, 0, 4);
146 	input_set_abs_params(input_dev, ABS_Y, -64, 64, 0, 4);
147 
148 	serio_set_drvdata(serio, stinger);
149 
150 	err = serio_open(serio, drv);
151 	if (err)
152 		goto fail2;
153 
154 	err = input_register_device(stinger->dev);
155 	if (err)
156 		goto fail3;
157 
158 	return 0;
159 
160  fail3:	serio_close(serio);
161  fail2:	serio_set_drvdata(serio, NULL);
162  fail1:	input_free_device(input_dev);
163 	kfree(stinger);
164 	return err;
165 }
166 
167 /*
168  * The serio driver structure.
169  */
170 
171 static const struct serio_device_id stinger_serio_ids[] = {
172 	{
173 		.type	= SERIO_RS232,
174 		.proto	= SERIO_STINGER,
175 		.id	= SERIO_ANY,
176 		.extra	= SERIO_ANY,
177 	},
178 	{ 0 }
179 };
180 
181 MODULE_DEVICE_TABLE(serio, stinger_serio_ids);
182 
183 static struct serio_driver stinger_drv = {
184 	.driver		= {
185 		.name	= "stinger",
186 	},
187 	.description	= DRIVER_DESC,
188 	.id_table	= stinger_serio_ids,
189 	.interrupt	= stinger_interrupt,
190 	.connect	= stinger_connect,
191 	.disconnect	= stinger_disconnect,
192 };
193 
194 module_serio_driver(stinger_drv);
195