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 | |
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 | |
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 | |
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 | |
107 | static void mtouch_disconnect(struct serio *serio) |
108 | { |
109 | struct mtouch *mtouch = serio_get_drvdata(serio); |
110 | |
111 | input_get_device(dev: mtouch->dev); |
112 | input_unregister_device(mtouch->dev); |
113 | serio_close(serio); |
114 | serio_set_drvdata(serio, NULL); |
115 | input_put_device(dev: mtouch->dev); |
116 | kfree(objp: 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 | |
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(size: sizeof(struct 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(buf: mtouch->phys, size: sizeof(mtouch->phys), fmt: "%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(dev: mtouch->dev, ABS_X, MTOUCH_MIN_XC, MTOUCH_MAX_XC, fuzz: 0, flat: 0); |
152 | input_set_abs_params(dev: mtouch->dev, ABS_Y, MTOUCH_MIN_YC, MTOUCH_MAX_YC, fuzz: 0, flat: 0); |
153 | |
154 | serio_set_drvdata(serio, data: 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(dev: input_dev); |
169 | kfree(objp: 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 | |