1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * Hampshire serial touchscreen driver |
4 | * |
5 | * Copyright (c) 2010 Adam Bennett |
6 | * Based on the dynapro driver (c) Tias Guns |
7 | */ |
8 | |
9 | |
10 | /* |
11 | * 2010/04/08 Adam Bennett <abennett72@gmail.com> |
12 | * Copied dynapro.c and edited for Hampshire 4-byte protocol |
13 | */ |
14 | |
15 | #include <linux/errno.h> |
16 | #include <linux/kernel.h> |
17 | #include <linux/module.h> |
18 | #include <linux/slab.h> |
19 | #include <linux/input.h> |
20 | #include <linux/serio.h> |
21 | |
22 | #define DRIVER_DESC "Hampshire serial touchscreen driver" |
23 | |
24 | MODULE_AUTHOR("Adam Bennett <abennett72@gmail.com>" ); |
25 | MODULE_DESCRIPTION(DRIVER_DESC); |
26 | MODULE_LICENSE("GPL" ); |
27 | |
28 | /* |
29 | * Definitions & global arrays. |
30 | */ |
31 | |
32 | #define HAMPSHIRE_FORMAT_TOUCH_BIT 0x40 |
33 | #define HAMPSHIRE_FORMAT_LENGTH 4 |
34 | #define HAMPSHIRE_RESPONSE_BEGIN_BYTE 0x80 |
35 | |
36 | #define HAMPSHIRE_MIN_XC 0 |
37 | #define HAMPSHIRE_MAX_XC 0x1000 |
38 | #define HAMPSHIRE_MIN_YC 0 |
39 | #define HAMPSHIRE_MAX_YC 0x1000 |
40 | |
41 | #define HAMPSHIRE_GET_XC(data) (((data[3] & 0x0c) >> 2) | (data[1] << 2) | ((data[0] & 0x38) << 6)) |
42 | #define HAMPSHIRE_GET_YC(data) ((data[3] & 0x03) | (data[2] << 2) | ((data[0] & 0x07) << 9)) |
43 | #define HAMPSHIRE_GET_TOUCHED(data) (HAMPSHIRE_FORMAT_TOUCH_BIT & data[0]) |
44 | |
45 | /* |
46 | * Per-touchscreen data. |
47 | */ |
48 | |
49 | struct hampshire { |
50 | struct input_dev *dev; |
51 | struct serio *serio; |
52 | int idx; |
53 | unsigned char data[HAMPSHIRE_FORMAT_LENGTH]; |
54 | char phys[32]; |
55 | }; |
56 | |
57 | static void hampshire_process_data(struct hampshire *phampshire) |
58 | { |
59 | struct input_dev *dev = phampshire->dev; |
60 | |
61 | if (HAMPSHIRE_FORMAT_LENGTH == ++phampshire->idx) { |
62 | input_report_abs(dev, ABS_X, HAMPSHIRE_GET_XC(phampshire->data)); |
63 | input_report_abs(dev, ABS_Y, HAMPSHIRE_GET_YC(phampshire->data)); |
64 | input_report_key(dev, BTN_TOUCH, |
65 | HAMPSHIRE_GET_TOUCHED(phampshire->data)); |
66 | input_sync(dev); |
67 | |
68 | phampshire->idx = 0; |
69 | } |
70 | } |
71 | |
72 | static irqreturn_t hampshire_interrupt(struct serio *serio, |
73 | unsigned char data, unsigned int flags) |
74 | { |
75 | struct hampshire *phampshire = serio_get_drvdata(serio); |
76 | |
77 | phampshire->data[phampshire->idx] = data; |
78 | |
79 | if (HAMPSHIRE_RESPONSE_BEGIN_BYTE & phampshire->data[0]) |
80 | hampshire_process_data(phampshire); |
81 | else |
82 | dev_dbg(&serio->dev, "unknown/unsynchronized data: %x\n" , |
83 | phampshire->data[0]); |
84 | |
85 | return IRQ_HANDLED; |
86 | } |
87 | |
88 | static void hampshire_disconnect(struct serio *serio) |
89 | { |
90 | struct hampshire *phampshire = serio_get_drvdata(serio); |
91 | |
92 | input_get_device(dev: phampshire->dev); |
93 | input_unregister_device(phampshire->dev); |
94 | serio_close(serio); |
95 | serio_set_drvdata(serio, NULL); |
96 | input_put_device(dev: phampshire->dev); |
97 | kfree(objp: phampshire); |
98 | } |
99 | |
100 | /* |
101 | * hampshire_connect() is the routine that is called when someone adds a |
102 | * new serio device that supports hampshire protocol and registers it as |
103 | * an input device. This is usually accomplished using inputattach. |
104 | */ |
105 | |
106 | static int hampshire_connect(struct serio *serio, struct serio_driver *drv) |
107 | { |
108 | struct hampshire *phampshire; |
109 | struct input_dev *input_dev; |
110 | int err; |
111 | |
112 | phampshire = kzalloc(size: sizeof(struct hampshire), GFP_KERNEL); |
113 | input_dev = input_allocate_device(); |
114 | if (!phampshire || !input_dev) { |
115 | err = -ENOMEM; |
116 | goto fail1; |
117 | } |
118 | |
119 | phampshire->serio = serio; |
120 | phampshire->dev = input_dev; |
121 | snprintf(buf: phampshire->phys, size: sizeof(phampshire->phys), |
122 | fmt: "%s/input0" , serio->phys); |
123 | |
124 | input_dev->name = "Hampshire Serial TouchScreen" ; |
125 | input_dev->phys = phampshire->phys; |
126 | input_dev->id.bustype = BUS_RS232; |
127 | input_dev->id.vendor = SERIO_HAMPSHIRE; |
128 | input_dev->id.product = 0; |
129 | input_dev->id.version = 0x0001; |
130 | input_dev->dev.parent = &serio->dev; |
131 | input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS); |
132 | input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH); |
133 | input_set_abs_params(dev: phampshire->dev, ABS_X, |
134 | HAMPSHIRE_MIN_XC, HAMPSHIRE_MAX_XC, fuzz: 0, flat: 0); |
135 | input_set_abs_params(dev: phampshire->dev, ABS_Y, |
136 | HAMPSHIRE_MIN_YC, HAMPSHIRE_MAX_YC, fuzz: 0, flat: 0); |
137 | |
138 | serio_set_drvdata(serio, data: phampshire); |
139 | |
140 | err = serio_open(serio, drv); |
141 | if (err) |
142 | goto fail2; |
143 | |
144 | err = input_register_device(phampshire->dev); |
145 | if (err) |
146 | goto fail3; |
147 | |
148 | return 0; |
149 | |
150 | fail3: serio_close(serio); |
151 | fail2: serio_set_drvdata(serio, NULL); |
152 | fail1: input_free_device(dev: input_dev); |
153 | kfree(objp: phampshire); |
154 | return err; |
155 | } |
156 | |
157 | /* |
158 | * The serio driver structure. |
159 | */ |
160 | |
161 | static const struct serio_device_id hampshire_serio_ids[] = { |
162 | { |
163 | .type = SERIO_RS232, |
164 | .proto = SERIO_HAMPSHIRE, |
165 | .id = SERIO_ANY, |
166 | .extra = SERIO_ANY, |
167 | }, |
168 | { 0 } |
169 | }; |
170 | |
171 | MODULE_DEVICE_TABLE(serio, hampshire_serio_ids); |
172 | |
173 | static struct serio_driver hampshire_drv = { |
174 | .driver = { |
175 | .name = "hampshire" , |
176 | }, |
177 | .description = DRIVER_DESC, |
178 | .id_table = hampshire_serio_ids, |
179 | .interrupt = hampshire_interrupt, |
180 | .connect = hampshire_connect, |
181 | .disconnect = hampshire_disconnect, |
182 | }; |
183 | |
184 | module_serio_driver(hampshire_drv); |
185 | |