1
2
3
4
5
6
7
8
9
10
11
12
13
14
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
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
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
97
98
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
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");
195
