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1/*
2 * EETI Egalax serial touchscreen driver
3 *
4 * Copyright (c) 2015 Zoltán Böszörményi <zboszor@pr.hu>
5 *
6 * based on the
7 *
8 * Hampshire serial touchscreen driver (Copyright (c) 2010 Adam Bennett)
9 */
10
11/*
12 * This program is free software; you can redistribute it and/or modify it
13 * under the terms of the GNU General Public License version 2 as published by
14 * the Free Software Foundation.
15 */
16
17#include <linux/errno.h>
18#include <linux/kernel.h>
19#include <linux/module.h>
20#include <linux/slab.h>
21#include <linux/input.h>
22#include <linux/serio.h>
23
24#define DRIVER_DESC "EETI Egalax serial touchscreen driver"
25
26/*
27 * Definitions & global arrays.
28 */
29
30#define EGALAX_FORMAT_MAX_LENGTH 6
31#define EGALAX_FORMAT_START_BIT BIT(7)
32#define EGALAX_FORMAT_PRESSURE_BIT BIT(6)
33#define EGALAX_FORMAT_TOUCH_BIT BIT(0)
34#define EGALAX_FORMAT_RESOLUTION_MASK 0x06
35
36#define EGALAX_MIN_XC 0
37#define EGALAX_MAX_XC 0x4000
38#define EGALAX_MIN_YC 0
39#define EGALAX_MAX_YC 0x4000
40
41/*
42 * Per-touchscreen data.
43 */
44struct egalax {
45 struct input_dev *input;
46 struct serio *serio;
47 int idx;
48 u8 data[EGALAX_FORMAT_MAX_LENGTH];
49 char phys[32];
50};
51
52static void egalax_process_data(struct egalax *egalax)
53{
54 struct input_dev *dev = egalax->input;
55 u8 *data = egalax->data;
56 u16 x, y;
57 u8 shift;
58 u8 mask;
59
60 shift = 3 - ((data[0] & EGALAX_FORMAT_RESOLUTION_MASK) >> 1);
61 mask = 0xff >> (shift + 1);
62
63 x = (((u16)(data[1] & mask) << 7) | (data[2] & 0x7f)) << shift;
64 y = (((u16)(data[3] & mask) << 7) | (data[4] & 0x7f)) << shift;
65
66 input_report_key(dev, BTN_TOUCH, data[0] & EGALAX_FORMAT_TOUCH_BIT);
67 input_report_abs(dev, ABS_X, x);
68 input_report_abs(dev, ABS_Y, y);
69 input_sync(dev);
70}
71
72static irqreturn_t egalax_interrupt(struct serio *serio,
73 unsigned char data, unsigned int flags)
74{
75 struct egalax *egalax = serio_get_drvdata(serio);
76 int pkt_len;
77
78 egalax->data[egalax->idx++] = data;
79
80 if (likely(egalax->data[0] & EGALAX_FORMAT_START_BIT)) {
81 pkt_len = egalax->data[0] & EGALAX_FORMAT_PRESSURE_BIT ? 6 : 5;
82 if (pkt_len == egalax->idx) {
83 egalax_process_data(egalax);
84 egalax->idx = 0;
85 }
86 } else {
87 dev_dbg(&serio->dev, "unknown/unsynchronized data: %x\n",
88 egalax->data[0]);
89 egalax->idx = 0;
90 }
91
92 return IRQ_HANDLED;
93}
94
95/*
96 * egalax_connect() is the routine that is called when someone adds a
97 * new serio device that supports egalax protocol and registers it as
98 * an input device. This is usually accomplished using inputattach.
99 */
100static int egalax_connect(struct serio *serio, struct serio_driver *drv)
101{
102 struct egalax *egalax;
103 struct input_dev *input_dev;
104 int error;
105
106 egalax = kzalloc(sizeof(struct egalax), GFP_KERNEL);
107 input_dev = input_allocate_device();
108 if (!egalax || !input_dev) {
109 error = -ENOMEM;
110 goto err_free_mem;
111 }
112
113 egalax->serio = serio;
114 egalax->input = input_dev;
115 snprintf(egalax->phys, sizeof(egalax->phys),
116 "%s/input0", serio->phys);
117
118 input_dev->name = "EETI eGalaxTouch Serial TouchScreen";
119 input_dev->phys = egalax->phys;
120 input_dev->id.bustype = BUS_RS232;
121 input_dev->id.vendor = SERIO_EGALAX;
122 input_dev->id.product = 0;
123 input_dev->id.version = 0x0001;
124 input_dev->dev.parent = &serio->dev;
125
126 input_set_capability(input_dev, EV_KEY, BTN_TOUCH);
127 input_set_abs_params(input_dev, ABS_X,
128 EGALAX_MIN_XC, EGALAX_MAX_XC, 0, 0);
129 input_set_abs_params(input_dev, ABS_Y,
130 EGALAX_MIN_YC, EGALAX_MAX_YC, 0, 0);
131
132 serio_set_drvdata(serio, egalax);
133
134 error = serio_open(serio, drv);
135 if (error)
136 goto err_reset_drvdata;
137
138 error = input_register_device(input_dev);
139 if (error)
140 goto err_close_serio;
141
142 return 0;
143
144err_close_serio:
145 serio_close(serio);
146err_reset_drvdata:
147 serio_set_drvdata(serio, NULL);
148err_free_mem:
149 input_free_device(input_dev);
150 kfree(egalax);
151 return error;
152}
153
154static void egalax_disconnect(struct serio *serio)
155{
156 struct egalax *egalax = serio_get_drvdata(serio);
157
158 serio_close(serio);
159 serio_set_drvdata(serio, NULL);
160 input_unregister_device(egalax->input);
161 kfree(egalax);
162}
163
164/*
165 * The serio driver structure.
166 */
167
168static const struct serio_device_id egalax_serio_ids[] = {
169 {
170 .type = SERIO_RS232,
171 .proto = SERIO_EGALAX,
172 .id = SERIO_ANY,
173 .extra = SERIO_ANY,
174 },
175 { 0 }
176};
177
178MODULE_DEVICE_TABLE(serio, egalax_serio_ids);
179
180static struct serio_driver egalax_drv = {
181 .driver = {
182 .name = "egalax",
183 },
184 .description = DRIVER_DESC,
185 .id_table = egalax_serio_ids,
186 .interrupt = egalax_interrupt,
187 .connect = egalax_connect,
188 .disconnect = egalax_disconnect,
189};
190module_serio_driver(egalax_drv);
191
192MODULE_AUTHOR("Zoltán Böszörményi <zboszor@pr.hu>");
193MODULE_DESCRIPTION(DRIVER_DESC);
194MODULE_LICENSE("GPL v2");
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * EETI Egalax serial touchscreen driver
4 *
5 * Copyright (c) 2015 Zoltán Böszörményi <zboszor@pr.hu>
6 *
7 * based on the
8 *
9 * Hampshire serial touchscreen driver (Copyright (c) 2010 Adam Bennett)
10 */
11
12
13#include <linux/errno.h>
14#include <linux/kernel.h>
15#include <linux/module.h>
16#include <linux/slab.h>
17#include <linux/input.h>
18#include <linux/serio.h>
19
20#define DRIVER_DESC "EETI Egalax serial touchscreen driver"
21
22/*
23 * Definitions & global arrays.
24 */
25
26#define EGALAX_FORMAT_MAX_LENGTH 6
27#define EGALAX_FORMAT_START_BIT BIT(7)
28#define EGALAX_FORMAT_PRESSURE_BIT BIT(6)
29#define EGALAX_FORMAT_TOUCH_BIT BIT(0)
30#define EGALAX_FORMAT_RESOLUTION_MASK 0x06
31
32#define EGALAX_MIN_XC 0
33#define EGALAX_MAX_XC 0x4000
34#define EGALAX_MIN_YC 0
35#define EGALAX_MAX_YC 0x4000
36
37/*
38 * Per-touchscreen data.
39 */
40struct egalax {
41 struct input_dev *input;
42 struct serio *serio;
43 int idx;
44 u8 data[EGALAX_FORMAT_MAX_LENGTH];
45 char phys[32];
46};
47
48static void egalax_process_data(struct egalax *egalax)
49{
50 struct input_dev *dev = egalax->input;
51 u8 *data = egalax->data;
52 u16 x, y;
53 u8 shift;
54 u8 mask;
55
56 shift = 3 - ((data[0] & EGALAX_FORMAT_RESOLUTION_MASK) >> 1);
57 mask = 0xff >> (shift + 1);
58
59 x = (((u16)(data[1] & mask) << 7) | (data[2] & 0x7f)) << shift;
60 y = (((u16)(data[3] & mask) << 7) | (data[4] & 0x7f)) << shift;
61
62 input_report_key(dev, BTN_TOUCH, data[0] & EGALAX_FORMAT_TOUCH_BIT);
63 input_report_abs(dev, ABS_X, x);
64 input_report_abs(dev, ABS_Y, y);
65 input_sync(dev);
66}
67
68static irqreturn_t egalax_interrupt(struct serio *serio,
69 unsigned char data, unsigned int flags)
70{
71 struct egalax *egalax = serio_get_drvdata(serio);
72 int pkt_len;
73
74 egalax->data[egalax->idx++] = data;
75
76 if (likely(egalax->data[0] & EGALAX_FORMAT_START_BIT)) {
77 pkt_len = egalax->data[0] & EGALAX_FORMAT_PRESSURE_BIT ? 6 : 5;
78 if (pkt_len == egalax->idx) {
79 egalax_process_data(egalax);
80 egalax->idx = 0;
81 }
82 } else {
83 dev_dbg(&serio->dev, "unknown/unsynchronized data: %x\n",
84 egalax->data[0]);
85 egalax->idx = 0;
86 }
87
88 return IRQ_HANDLED;
89}
90
91/*
92 * egalax_connect() is the routine that is called when someone adds a
93 * new serio device that supports egalax protocol and registers it as
94 * an input device. This is usually accomplished using inputattach.
95 */
96static int egalax_connect(struct serio *serio, struct serio_driver *drv)
97{
98 struct egalax *egalax;
99 struct input_dev *input_dev;
100 int error;
101
102 egalax = kzalloc(sizeof(struct egalax), GFP_KERNEL);
103 input_dev = input_allocate_device();
104 if (!egalax || !input_dev) {
105 error = -ENOMEM;
106 goto err_free_mem;
107 }
108
109 egalax->serio = serio;
110 egalax->input = input_dev;
111 snprintf(egalax->phys, sizeof(egalax->phys),
112 "%s/input0", serio->phys);
113
114 input_dev->name = "EETI eGalaxTouch Serial TouchScreen";
115 input_dev->phys = egalax->phys;
116 input_dev->id.bustype = BUS_RS232;
117 input_dev->id.vendor = SERIO_EGALAX;
118 input_dev->id.product = 0;
119 input_dev->id.version = 0x0001;
120 input_dev->dev.parent = &serio->dev;
121
122 input_set_capability(input_dev, EV_KEY, BTN_TOUCH);
123 input_set_abs_params(input_dev, ABS_X,
124 EGALAX_MIN_XC, EGALAX_MAX_XC, 0, 0);
125 input_set_abs_params(input_dev, ABS_Y,
126 EGALAX_MIN_YC, EGALAX_MAX_YC, 0, 0);
127
128 serio_set_drvdata(serio, egalax);
129
130 error = serio_open(serio, drv);
131 if (error)
132 goto err_reset_drvdata;
133
134 error = input_register_device(input_dev);
135 if (error)
136 goto err_close_serio;
137
138 return 0;
139
140err_close_serio:
141 serio_close(serio);
142err_reset_drvdata:
143 serio_set_drvdata(serio, NULL);
144err_free_mem:
145 input_free_device(input_dev);
146 kfree(egalax);
147 return error;
148}
149
150static void egalax_disconnect(struct serio *serio)
151{
152 struct egalax *egalax = serio_get_drvdata(serio);
153
154 serio_close(serio);
155 serio_set_drvdata(serio, NULL);
156 input_unregister_device(egalax->input);
157 kfree(egalax);
158}
159
160/*
161 * The serio driver structure.
162 */
163
164static const struct serio_device_id egalax_serio_ids[] = {
165 {
166 .type = SERIO_RS232,
167 .proto = SERIO_EGALAX,
168 .id = SERIO_ANY,
169 .extra = SERIO_ANY,
170 },
171 { 0 }
172};
173
174MODULE_DEVICE_TABLE(serio, egalax_serio_ids);
175
176static struct serio_driver egalax_drv = {
177 .driver = {
178 .name = "egalax",
179 },
180 .description = DRIVER_DESC,
181 .id_table = egalax_serio_ids,
182 .interrupt = egalax_interrupt,
183 .connect = egalax_connect,
184 .disconnect = egalax_disconnect,
185};
186module_serio_driver(egalax_drv);
187
188MODULE_AUTHOR("Zoltán Böszörményi <zboszor@pr.hu>");
189MODULE_DESCRIPTION(DRIVER_DESC);
190MODULE_LICENSE("GPL v2");