1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * Fujitsu serial touchscreen driver |
4 | * |
5 | * Copyright (c) Dmitry Torokhov <dtor@mail.ru> |
6 | */ |
7 | |
8 | |
9 | #include <linux/errno.h> |
10 | #include <linux/kernel.h> |
11 | #include <linux/module.h> |
12 | #include <linux/slab.h> |
13 | #include <linux/input.h> |
14 | #include <linux/serio.h> |
15 | |
16 | #define DRIVER_DESC "Fujitsu serial touchscreen driver" |
17 | |
18 | MODULE_AUTHOR("Dmitry Torokhov <dtor@mail.ru>" ); |
19 | MODULE_DESCRIPTION(DRIVER_DESC); |
20 | MODULE_LICENSE("GPL" ); |
21 | |
22 | #define FUJITSU_LENGTH 5 |
23 | |
24 | /* |
25 | * Per-touchscreen data. |
26 | */ |
27 | struct fujitsu { |
28 | struct input_dev *dev; |
29 | struct serio *serio; |
30 | int idx; |
31 | unsigned char data[FUJITSU_LENGTH]; |
32 | char phys[32]; |
33 | }; |
34 | |
35 | /* |
36 | * Decode serial data (5 bytes per packet) |
37 | * First byte |
38 | * 1 C 0 0 R S S S |
39 | * Where C is 1 while in calibration mode (which we don't use) |
40 | * R is 1 when no coordinate corection was done. |
41 | * S are button state |
42 | */ |
43 | static irqreturn_t fujitsu_interrupt(struct serio *serio, |
44 | unsigned char data, unsigned int flags) |
45 | { |
46 | struct fujitsu *fujitsu = serio_get_drvdata(serio); |
47 | struct input_dev *dev = fujitsu->dev; |
48 | |
49 | if (fujitsu->idx == 0) { |
50 | /* resync skip until start of frame */ |
51 | if ((data & 0xf0) != 0x80) |
52 | return IRQ_HANDLED; |
53 | } else { |
54 | /* resync skip garbage */ |
55 | if (data & 0x80) { |
56 | fujitsu->idx = 0; |
57 | return IRQ_HANDLED; |
58 | } |
59 | } |
60 | |
61 | fujitsu->data[fujitsu->idx++] = data; |
62 | if (fujitsu->idx == FUJITSU_LENGTH) { |
63 | input_report_abs(dev, ABS_X, |
64 | value: (fujitsu->data[2] << 7) | fujitsu->data[1]); |
65 | input_report_abs(dev, ABS_Y, |
66 | value: (fujitsu->data[4] << 7) | fujitsu->data[3]); |
67 | input_report_key(dev, BTN_TOUCH, |
68 | value: (fujitsu->data[0] & 0x03) != 2); |
69 | input_sync(dev); |
70 | fujitsu->idx = 0; |
71 | } |
72 | |
73 | return IRQ_HANDLED; |
74 | } |
75 | |
76 | /* |
77 | * fujitsu_disconnect() is the opposite of fujitsu_connect() |
78 | */ |
79 | static void fujitsu_disconnect(struct serio *serio) |
80 | { |
81 | struct fujitsu *fujitsu = serio_get_drvdata(serio); |
82 | |
83 | input_get_device(dev: fujitsu->dev); |
84 | input_unregister_device(fujitsu->dev); |
85 | serio_close(serio); |
86 | serio_set_drvdata(serio, NULL); |
87 | input_put_device(dev: fujitsu->dev); |
88 | kfree(objp: fujitsu); |
89 | } |
90 | |
91 | /* |
92 | * fujitsu_connect() is the routine that is called when someone adds a |
93 | * new serio device that supports the Fujitsu protocol and registers it |
94 | * as input device. |
95 | */ |
96 | static int fujitsu_connect(struct serio *serio, struct serio_driver *drv) |
97 | { |
98 | struct fujitsu *fujitsu; |
99 | struct input_dev *input_dev; |
100 | int err; |
101 | |
102 | fujitsu = kzalloc(size: sizeof(struct fujitsu), GFP_KERNEL); |
103 | input_dev = input_allocate_device(); |
104 | if (!fujitsu || !input_dev) { |
105 | err = -ENOMEM; |
106 | goto fail1; |
107 | } |
108 | |
109 | fujitsu->serio = serio; |
110 | fujitsu->dev = input_dev; |
111 | snprintf(buf: fujitsu->phys, size: sizeof(fujitsu->phys), |
112 | fmt: "%s/input0" , serio->phys); |
113 | |
114 | input_dev->name = "Fujitsu Serial Touchscreen" ; |
115 | input_dev->phys = fujitsu->phys; |
116 | input_dev->id.bustype = BUS_RS232; |
117 | input_dev->id.vendor = SERIO_FUJITSU; |
118 | input_dev->id.product = 0; |
119 | input_dev->id.version = 0x0100; |
120 | input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS); |
121 | input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH); |
122 | |
123 | input_set_abs_params(dev: input_dev, ABS_X, min: 0, max: 4096, fuzz: 0, flat: 0); |
124 | input_set_abs_params(dev: input_dev, ABS_Y, min: 0, max: 4096, fuzz: 0, flat: 0); |
125 | serio_set_drvdata(serio, data: fujitsu); |
126 | |
127 | err = serio_open(serio, drv); |
128 | if (err) |
129 | goto fail2; |
130 | |
131 | err = input_register_device(fujitsu->dev); |
132 | if (err) |
133 | goto fail3; |
134 | |
135 | return 0; |
136 | |
137 | fail3: |
138 | serio_close(serio); |
139 | fail2: |
140 | serio_set_drvdata(serio, NULL); |
141 | fail1: |
142 | input_free_device(dev: input_dev); |
143 | kfree(objp: fujitsu); |
144 | return err; |
145 | } |
146 | |
147 | /* |
148 | * The serio driver structure. |
149 | */ |
150 | static const struct serio_device_id fujitsu_serio_ids[] = { |
151 | { |
152 | .type = SERIO_RS232, |
153 | .proto = SERIO_FUJITSU, |
154 | .id = SERIO_ANY, |
155 | .extra = SERIO_ANY, |
156 | }, |
157 | { 0 } |
158 | }; |
159 | |
160 | MODULE_DEVICE_TABLE(serio, fujitsu_serio_ids); |
161 | |
162 | static struct serio_driver fujitsu_drv = { |
163 | .driver = { |
164 | .name = "fujitsu_ts" , |
165 | }, |
166 | .description = DRIVER_DESC, |
167 | .id_table = fujitsu_serio_ids, |
168 | .interrupt = fujitsu_interrupt, |
169 | .connect = fujitsu_connect, |
170 | .disconnect = fujitsu_disconnect, |
171 | }; |
172 | |
173 | module_serio_driver(fujitsu_drv); |
174 | |