1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * MicroTouch (3M) serial touchscreen driver
4 *
5 * Copyright (c) 2004 Vojtech Pavlik
6 */
7
8
9 /*
10 * 2005/02/19 Dan Streetman <ddstreet@ieee.org>
11 * Copied elo.c and edited for MicroTouch protocol
12 */
13
14 #include <linux/errno.h>
15 #include <linux/kernel.h>
16 #include <linux/module.h>
17 #include <linux/slab.h>
18 #include <linux/input.h>
19 #include <linux/serio.h>
20
21 #define DRIVER_DESC "MicroTouch serial touchscreen driver"
22
23 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
24 MODULE_DESCRIPTION(DRIVER_DESC);
25 MODULE_LICENSE("GPL");
26
27 /*
28 * Definitions & global arrays.
29 */
30
31 #define MTOUCH_FORMAT_TABLET_STATUS_BIT 0x80
32 #define MTOUCH_FORMAT_TABLET_TOUCH_BIT 0x40
33 #define MTOUCH_FORMAT_TABLET_LENGTH 5
34 #define MTOUCH_RESPONSE_BEGIN_BYTE 0x01
35 #define MTOUCH_RESPONSE_END_BYTE 0x0d
36
37 /* todo: check specs for max length of all responses */
38 #define MTOUCH_MAX_LENGTH 16
39
40 #define MTOUCH_MIN_XC 0
41 #define MTOUCH_MAX_XC 0x3fff
42 #define MTOUCH_MIN_YC 0
43 #define MTOUCH_MAX_YC 0x3fff
44
45 #define MTOUCH_GET_XC(data) (((data[2])<<7) | data[1])
46 #define MTOUCH_GET_YC(data) (((data[4])<<7) | data[3])
47 #define MTOUCH_GET_TOUCHED(data) (MTOUCH_FORMAT_TABLET_TOUCH_BIT & data[0])
48
49 /*
50 * Per-touchscreen data.
51 */
52
53 struct mtouch {
54 struct input_dev *dev;
55 struct serio *serio;
56 int idx;
57 unsigned char data[MTOUCH_MAX_LENGTH];
58 char phys[32];
59 };
60
mtouch_process_format_tablet(struct mtouch * mtouch)61 static void mtouch_process_format_tablet(struct mtouch *mtouch)
62 {
63 struct input_dev *dev = mtouch->dev;
64
65 if (MTOUCH_FORMAT_TABLET_LENGTH == ++mtouch->idx) {
66 input_report_abs(dev, ABS_X, MTOUCH_GET_XC(mtouch->data));
67 input_report_abs(dev, ABS_Y, MTOUCH_MAX_YC - MTOUCH_GET_YC(mtouch->data));
68 input_report_key(dev, BTN_TOUCH, MTOUCH_GET_TOUCHED(mtouch->data));
69 input_sync(dev);
70
71 mtouch->idx = 0;
72 }
73 }
74
mtouch_process_response(struct mtouch * mtouch)75 static void mtouch_process_response(struct mtouch *mtouch)
76 {
77 if (MTOUCH_RESPONSE_END_BYTE == mtouch->data[mtouch->idx++]) {
78 /* FIXME - process response */
79 mtouch->idx = 0;
80 } else if (MTOUCH_MAX_LENGTH == mtouch->idx) {
81 printk(KERN_ERR "mtouch.c: too many response bytes\n");
82 mtouch->idx = 0;
83 }
84 }
85
mtouch_interrupt(struct serio * serio,unsigned char data,unsigned int flags)86 static irqreturn_t mtouch_interrupt(struct serio *serio,
87 unsigned char data, unsigned int flags)
88 {
89 struct mtouch *mtouch = serio_get_drvdata(serio);
90
91 mtouch->data[mtouch->idx] = data;
92
93 if (MTOUCH_FORMAT_TABLET_STATUS_BIT & mtouch->data[0])
94 mtouch_process_format_tablet(mtouch);
95 else if (MTOUCH_RESPONSE_BEGIN_BYTE == mtouch->data[0])
96 mtouch_process_response(mtouch);
97 else
98 printk(KERN_DEBUG "mtouch.c: unknown/unsynchronized data from device, byte %x\n",mtouch->data[0]);
99
100 return IRQ_HANDLED;
101 }
102
103 /*
104 * mtouch_disconnect() is the opposite of mtouch_connect()
105 */
106
mtouch_disconnect(struct serio * serio)107 static void mtouch_disconnect(struct serio *serio)
108 {
109 struct mtouch *mtouch = serio_get_drvdata(serio);
110
111 input_get_device(mtouch->dev);
112 input_unregister_device(mtouch->dev);
113 serio_close(serio);
114 serio_set_drvdata(serio, NULL);
115 input_put_device(mtouch->dev);
116 kfree(mtouch);
117 }
118
119 /*
120 * mtouch_connect() is the routine that is called when someone adds a
121 * new serio device that supports MicroTouch (Format Tablet) protocol and registers it as
122 * an input device.
123 */
124
mtouch_connect(struct serio * serio,struct serio_driver * drv)125 static int mtouch_connect(struct serio *serio, struct serio_driver *drv)
126 {
127 struct mtouch *mtouch;
128 struct input_dev *input_dev;
129 int err;
130
131 mtouch = kzalloc(sizeof(*mtouch), GFP_KERNEL);
132 input_dev = input_allocate_device();
133 if (!mtouch || !input_dev) {
134 err = -ENOMEM;
135 goto fail1;
136 }
137
138 mtouch->serio = serio;
139 mtouch->dev = input_dev;
140 snprintf(mtouch->phys, sizeof(mtouch->phys), "%s/input0", serio->phys);
141
142 input_dev->name = "MicroTouch Serial TouchScreen";
143 input_dev->phys = mtouch->phys;
144 input_dev->id.bustype = BUS_RS232;
145 input_dev->id.vendor = SERIO_MICROTOUCH;
146 input_dev->id.product = 0;
147 input_dev->id.version = 0x0100;
148 input_dev->dev.parent = &serio->dev;
149 input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
150 input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
151 input_set_abs_params(mtouch->dev, ABS_X, MTOUCH_MIN_XC, MTOUCH_MAX_XC, 0, 0);
152 input_set_abs_params(mtouch->dev, ABS_Y, MTOUCH_MIN_YC, MTOUCH_MAX_YC, 0, 0);
153
154 serio_set_drvdata(serio, mtouch);
155
156 err = serio_open(serio, drv);
157 if (err)
158 goto fail2;
159
160 err = input_register_device(mtouch->dev);
161 if (err)
162 goto fail3;
163
164 return 0;
165
166 fail3: serio_close(serio);
167 fail2: serio_set_drvdata(serio, NULL);
168 fail1: input_free_device(input_dev);
169 kfree(mtouch);
170 return err;
171 }
172
173 /*
174 * The serio driver structure.
175 */
176
177 static const struct serio_device_id mtouch_serio_ids[] = {
178 {
179 .type = SERIO_RS232,
180 .proto = SERIO_MICROTOUCH,
181 .id = SERIO_ANY,
182 .extra = SERIO_ANY,
183 },
184 { 0 }
185 };
186
187 MODULE_DEVICE_TABLE(serio, mtouch_serio_ids);
188
189 static struct serio_driver mtouch_drv = {
190 .driver = {
191 .name = "mtouch",
192 },
193 .description = DRIVER_DESC,
194 .id_table = mtouch_serio_ids,
195 .interrupt = mtouch_interrupt,
196 .connect = mtouch_connect,
197 .disconnect = mtouch_disconnect,
198 };
199
200 module_serio_driver(mtouch_drv);
201