1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * Touchwindow serial touchscreen driver |
4 | * |
5 | * Copyright (c) 2006 Rick Koch <n1gp@hotmail.com> |
6 | * |
7 | * Based on MicroTouch driver (drivers/input/touchscreen/mtouch.c) |
8 | * Copyright (c) 2004 Vojtech Pavlik |
9 | * and Dan Streetman <ddstreet@ieee.org> |
10 | */ |
11 | |
12 | |
13 | /* |
14 | * 2005/02/19 Rick Koch: |
15 | * The Touchwindow I used is made by Edmark Corp. and |
16 | * constantly outputs a stream of 0's unless it is touched. |
17 | * It then outputs 3 bytes: X, Y, and a copy of Y. |
18 | */ |
19 | |
20 | #include <linux/errno.h> |
21 | #include <linux/kernel.h> |
22 | #include <linux/module.h> |
23 | #include <linux/slab.h> |
24 | #include <linux/input.h> |
25 | #include <linux/serio.h> |
26 | |
27 | #define DRIVER_DESC "Touchwindow serial touchscreen driver" |
28 | |
29 | MODULE_AUTHOR("Rick Koch <n1gp@hotmail.com>" ); |
30 | MODULE_DESCRIPTION(DRIVER_DESC); |
31 | MODULE_LICENSE("GPL" ); |
32 | |
33 | /* |
34 | * Definitions & global arrays. |
35 | */ |
36 | |
37 | #define TW_LENGTH 3 |
38 | |
39 | #define TW_MIN_XC 0 |
40 | #define TW_MAX_XC 0xff |
41 | #define TW_MIN_YC 0 |
42 | #define TW_MAX_YC 0xff |
43 | |
44 | /* |
45 | * Per-touchscreen data. |
46 | */ |
47 | |
48 | struct tw { |
49 | struct input_dev *dev; |
50 | struct serio *serio; |
51 | int idx; |
52 | int touched; |
53 | unsigned char data[TW_LENGTH]; |
54 | char phys[32]; |
55 | }; |
56 | |
57 | static irqreturn_t tw_interrupt(struct serio *serio, |
58 | unsigned char data, unsigned int flags) |
59 | { |
60 | struct tw *tw = serio_get_drvdata(serio); |
61 | struct input_dev *dev = tw->dev; |
62 | |
63 | if (data) { /* touch */ |
64 | tw->touched = 1; |
65 | tw->data[tw->idx++] = data; |
66 | /* verify length and that the two Y's are the same */ |
67 | if (tw->idx == TW_LENGTH && tw->data[1] == tw->data[2]) { |
68 | input_report_abs(dev, ABS_X, value: tw->data[0]); |
69 | input_report_abs(dev, ABS_Y, value: tw->data[1]); |
70 | input_report_key(dev, BTN_TOUCH, value: 1); |
71 | input_sync(dev); |
72 | tw->idx = 0; |
73 | } |
74 | } else if (tw->touched) { /* untouch */ |
75 | input_report_key(dev, BTN_TOUCH, value: 0); |
76 | input_sync(dev); |
77 | tw->idx = 0; |
78 | tw->touched = 0; |
79 | } |
80 | |
81 | return IRQ_HANDLED; |
82 | } |
83 | |
84 | /* |
85 | * tw_disconnect() is the opposite of tw_connect() |
86 | */ |
87 | |
88 | static void tw_disconnect(struct serio *serio) |
89 | { |
90 | struct tw *tw = serio_get_drvdata(serio); |
91 | |
92 | input_get_device(dev: tw->dev); |
93 | input_unregister_device(tw->dev); |
94 | serio_close(serio); |
95 | serio_set_drvdata(serio, NULL); |
96 | input_put_device(dev: tw->dev); |
97 | kfree(objp: tw); |
98 | } |
99 | |
100 | /* |
101 | * tw_connect() is the routine that is called when someone adds a |
102 | * new serio device that supports the Touchwin protocol and registers it as |
103 | * an input device. |
104 | */ |
105 | |
106 | static int tw_connect(struct serio *serio, struct serio_driver *drv) |
107 | { |
108 | struct tw *tw; |
109 | struct input_dev *input_dev; |
110 | int err; |
111 | |
112 | tw = kzalloc(size: sizeof(struct tw), GFP_KERNEL); |
113 | input_dev = input_allocate_device(); |
114 | if (!tw || !input_dev) { |
115 | err = -ENOMEM; |
116 | goto fail1; |
117 | } |
118 | |
119 | tw->serio = serio; |
120 | tw->dev = input_dev; |
121 | snprintf(buf: tw->phys, size: sizeof(tw->phys), fmt: "%s/input0" , serio->phys); |
122 | |
123 | input_dev->name = "Touchwindow Serial TouchScreen" ; |
124 | input_dev->phys = tw->phys; |
125 | input_dev->id.bustype = BUS_RS232; |
126 | input_dev->id.vendor = SERIO_TOUCHWIN; |
127 | input_dev->id.product = 0; |
128 | input_dev->id.version = 0x0100; |
129 | input_dev->dev.parent = &serio->dev; |
130 | input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS); |
131 | input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH); |
132 | input_set_abs_params(dev: tw->dev, ABS_X, TW_MIN_XC, TW_MAX_XC, fuzz: 0, flat: 0); |
133 | input_set_abs_params(dev: tw->dev, ABS_Y, TW_MIN_YC, TW_MAX_YC, fuzz: 0, flat: 0); |
134 | |
135 | serio_set_drvdata(serio, data: tw); |
136 | |
137 | err = serio_open(serio, drv); |
138 | if (err) |
139 | goto fail2; |
140 | |
141 | err = input_register_device(tw->dev); |
142 | if (err) |
143 | goto fail3; |
144 | |
145 | return 0; |
146 | |
147 | fail3: serio_close(serio); |
148 | fail2: serio_set_drvdata(serio, NULL); |
149 | fail1: input_free_device(dev: input_dev); |
150 | kfree(objp: tw); |
151 | return err; |
152 | } |
153 | |
154 | /* |
155 | * The serio driver structure. |
156 | */ |
157 | |
158 | static const struct serio_device_id tw_serio_ids[] = { |
159 | { |
160 | .type = SERIO_RS232, |
161 | .proto = SERIO_TOUCHWIN, |
162 | .id = SERIO_ANY, |
163 | .extra = SERIO_ANY, |
164 | }, |
165 | { 0 } |
166 | }; |
167 | |
168 | MODULE_DEVICE_TABLE(serio, tw_serio_ids); |
169 | |
170 | static struct serio_driver tw_drv = { |
171 | .driver = { |
172 | .name = "touchwin" , |
173 | }, |
174 | .description = DRIVER_DESC, |
175 | .id_table = tw_serio_ids, |
176 | .interrupt = tw_interrupt, |
177 | .connect = tw_connect, |
178 | .disconnect = tw_disconnect, |
179 | }; |
180 | |
181 | module_serio_driver(tw_drv); |
182 | |