1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * Sahara TouchIT-213 serial touchscreen driver |
4 | * |
5 | * Copyright (c) 2007-2008 Claudio Nieder <private@claudio.ch> |
6 | * |
7 | * Based on Touchright driver (drivers/input/touchscreen/touchright.c) |
8 | * Copyright (c) 2006 Rick Koch <n1gp@hotmail.com> |
9 | * Copyright (c) 2004 Vojtech Pavlik |
10 | * and Dan Streetman <ddstreet@ieee.org> |
11 | */ |
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 "Sahara TouchIT-213 serial touchscreen driver" |
22 | |
23 | MODULE_AUTHOR("Claudio Nieder <private@claudio.ch>" ); |
24 | MODULE_DESCRIPTION(DRIVER_DESC); |
25 | MODULE_LICENSE("GPL" ); |
26 | |
27 | /* |
28 | * Definitions & global arrays. |
29 | */ |
30 | |
31 | /* |
32 | * Data is received through COM1 at 9600bit/s,8bit,no parity in packets |
33 | * of 5 byte each. |
34 | * |
35 | * +--------+ +--------+ +--------+ +--------+ +--------+ |
36 | * |1000000p| |0xxxxxxx| |0xxxxxxx| |0yyyyyyy| |0yyyyyyy| |
37 | * +--------+ +--------+ +--------+ +--------+ +--------+ |
38 | * MSB LSB MSB LSB |
39 | * |
40 | * The value of p is 1 as long as the screen is touched and 0 when |
41 | * reporting the location where touching stopped, e.g. where the pen was |
42 | * lifted from the screen. |
43 | * |
44 | * When holding the screen in landscape mode as the BIOS text output is |
45 | * presented, x is the horizontal axis with values growing from left to |
46 | * right and y is the vertical axis with values growing from top to |
47 | * bottom. |
48 | * |
49 | * When holding the screen in portrait mode with the Sahara logo in its |
50 | * correct position, x ist the vertical axis with values growing from |
51 | * top to bottom and y is the horizontal axis with values growing from |
52 | * right to left. |
53 | */ |
54 | |
55 | #define T213_FORMAT_TOUCH_BIT 0x01 |
56 | #define T213_FORMAT_STATUS_BYTE 0x80 |
57 | #define T213_FORMAT_STATUS_MASK ~T213_FORMAT_TOUCH_BIT |
58 | |
59 | /* |
60 | * On my Sahara Touch-IT 213 I have observed x values from 0 to 0x7f0 |
61 | * and y values from 0x1d to 0x7e9, so the actual measurement is |
62 | * probably done with an 11 bit precision. |
63 | */ |
64 | #define T213_MIN_XC 0 |
65 | #define T213_MAX_XC 0x07ff |
66 | #define T213_MIN_YC 0 |
67 | #define T213_MAX_YC 0x07ff |
68 | |
69 | /* |
70 | * Per-touchscreen data. |
71 | */ |
72 | |
73 | struct touchit213 { |
74 | struct input_dev *dev; |
75 | struct serio *serio; |
76 | int idx; |
77 | unsigned char csum; |
78 | unsigned char data[5]; |
79 | char phys[32]; |
80 | }; |
81 | |
82 | static irqreturn_t touchit213_interrupt(struct serio *serio, |
83 | unsigned char data, unsigned int flags) |
84 | { |
85 | struct touchit213 *touchit213 = serio_get_drvdata(serio); |
86 | struct input_dev *dev = touchit213->dev; |
87 | |
88 | touchit213->data[touchit213->idx] = data; |
89 | |
90 | switch (touchit213->idx++) { |
91 | case 0: |
92 | if ((touchit213->data[0] & T213_FORMAT_STATUS_MASK) != |
93 | T213_FORMAT_STATUS_BYTE) { |
94 | pr_debug("unsynchronized data: 0x%02x\n" , data); |
95 | touchit213->idx = 0; |
96 | } |
97 | break; |
98 | |
99 | case 4: |
100 | touchit213->idx = 0; |
101 | input_report_abs(dev, ABS_X, |
102 | value: (touchit213->data[1] << 7) | touchit213->data[2]); |
103 | input_report_abs(dev, ABS_Y, |
104 | value: (touchit213->data[3] << 7) | touchit213->data[4]); |
105 | input_report_key(dev, BTN_TOUCH, |
106 | value: touchit213->data[0] & T213_FORMAT_TOUCH_BIT); |
107 | input_sync(dev); |
108 | break; |
109 | } |
110 | |
111 | return IRQ_HANDLED; |
112 | } |
113 | |
114 | /* |
115 | * touchit213_disconnect() is the opposite of touchit213_connect() |
116 | */ |
117 | |
118 | static void touchit213_disconnect(struct serio *serio) |
119 | { |
120 | struct touchit213 *touchit213 = serio_get_drvdata(serio); |
121 | |
122 | input_get_device(dev: touchit213->dev); |
123 | input_unregister_device(touchit213->dev); |
124 | serio_close(serio); |
125 | serio_set_drvdata(serio, NULL); |
126 | input_put_device(dev: touchit213->dev); |
127 | kfree(objp: touchit213); |
128 | } |
129 | |
130 | /* |
131 | * touchit213_connect() is the routine that is called when someone adds a |
132 | * new serio device that supports the Touchright protocol and registers it as |
133 | * an input device. |
134 | */ |
135 | |
136 | static int touchit213_connect(struct serio *serio, struct serio_driver *drv) |
137 | { |
138 | struct touchit213 *touchit213; |
139 | struct input_dev *input_dev; |
140 | int err; |
141 | |
142 | touchit213 = kzalloc(size: sizeof(struct touchit213), GFP_KERNEL); |
143 | input_dev = input_allocate_device(); |
144 | if (!touchit213 || !input_dev) { |
145 | err = -ENOMEM; |
146 | goto fail1; |
147 | } |
148 | |
149 | touchit213->serio = serio; |
150 | touchit213->dev = input_dev; |
151 | snprintf(buf: touchit213->phys, size: sizeof(touchit213->phys), |
152 | fmt: "%s/input0" , serio->phys); |
153 | |
154 | input_dev->name = "Sahara Touch-iT213 Serial TouchScreen" ; |
155 | input_dev->phys = touchit213->phys; |
156 | input_dev->id.bustype = BUS_RS232; |
157 | input_dev->id.vendor = SERIO_TOUCHIT213; |
158 | input_dev->id.product = 0; |
159 | input_dev->id.version = 0x0100; |
160 | input_dev->dev.parent = &serio->dev; |
161 | input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS); |
162 | input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH); |
163 | input_set_abs_params(dev: touchit213->dev, ABS_X, |
164 | T213_MIN_XC, T213_MAX_XC, fuzz: 0, flat: 0); |
165 | input_set_abs_params(dev: touchit213->dev, ABS_Y, |
166 | T213_MIN_YC, T213_MAX_YC, fuzz: 0, flat: 0); |
167 | |
168 | serio_set_drvdata(serio, data: touchit213); |
169 | |
170 | err = serio_open(serio, drv); |
171 | if (err) |
172 | goto fail2; |
173 | |
174 | err = input_register_device(touchit213->dev); |
175 | if (err) |
176 | goto fail3; |
177 | |
178 | return 0; |
179 | |
180 | fail3: serio_close(serio); |
181 | fail2: serio_set_drvdata(serio, NULL); |
182 | fail1: input_free_device(dev: input_dev); |
183 | kfree(objp: touchit213); |
184 | return err; |
185 | } |
186 | |
187 | /* |
188 | * The serio driver structure. |
189 | */ |
190 | |
191 | static const struct serio_device_id touchit213_serio_ids[] = { |
192 | { |
193 | .type = SERIO_RS232, |
194 | .proto = SERIO_TOUCHIT213, |
195 | .id = SERIO_ANY, |
196 | .extra = SERIO_ANY, |
197 | }, |
198 | { 0 } |
199 | }; |
200 | |
201 | MODULE_DEVICE_TABLE(serio, touchit213_serio_ids); |
202 | |
203 | static struct serio_driver touchit213_drv = { |
204 | .driver = { |
205 | .name = "touchit213" , |
206 | }, |
207 | .description = DRIVER_DESC, |
208 | .id_table = touchit213_serio_ids, |
209 | .interrupt = touchit213_interrupt, |
210 | .connect = touchit213_connect, |
211 | .disconnect = touchit213_disconnect, |
212 | }; |
213 | |
214 | module_serio_driver(touchit213_drv); |
215 | |