summaryrefslogtreecommitdiffstats
path: root/drivers/input/touchscreen/egalax_ts.c
blob: eadcc2e83c7756844ad109557bbb45c5fa72f6bb (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
/*
 * Driver for EETI eGalax Multiple Touch Controller
 *
 * Copyright (C) 2011 Freescale Semiconductor, Inc.
 *
 * based on max11801_ts.c
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

/* EETI eGalax serial touch screen controller is a I2C based multiple
 * touch screen controller, it supports 5 point multiple touch. */

/* TODO:
  - auto idle mode support
*/

#include <linux/module.h>
#include <linux/init.h>
#include <linux/i2c.h>
#include <linux/interrupt.h>
#include <linux/input.h>
#include <linux/irq.h>
#include <linux/gpio.h>
#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/bitops.h>
#include <linux/input/mt.h>

/*
 * Mouse Mode: some panel may configure the controller to mouse mode,
 * which can only report one point at a given time.
 * This driver will ignore events in this mode.
 */
#define REPORT_MODE_MOUSE		0x1
/*
 * Vendor Mode: this mode is used to transfer some vendor specific
 * messages.
 * This driver will ignore events in this mode.
 */
#define REPORT_MODE_VENDOR		0x3
/* Multiple Touch Mode */
#define REPORT_MODE_MTTOUCH		0x4

#define MAX_SUPPORT_POINTS		5

#define EVENT_VALID_OFFSET	7
#define EVENT_VALID_MASK	(0x1 << EVENT_VALID_OFFSET)
#define EVENT_ID_OFFSET		2
#define EVENT_ID_MASK		(0xf << EVENT_ID_OFFSET)
#define EVENT_IN_RANGE		(0x1 << 1)
#define EVENT_DOWN_UP		(0X1 << 0)

#define MAX_I2C_DATA_LEN	10

#define EGALAX_MAX_X	32760
#define EGALAX_MAX_Y	32760
#define EGALAX_MAX_TRIES 100

struct egalax_ts {
	struct i2c_client		*client;
	struct input_dev		*input_dev;
};

static irqreturn_t egalax_ts_interrupt(int irq, void *dev_id)
{
	struct egalax_ts *ts = dev_id;
	struct input_dev *input_dev = ts->input_dev;
	struct i2c_client *client = ts->client;
	u8 buf[MAX_I2C_DATA_LEN];
	int id, ret, x, y, z;
	int tries = 0;
	bool down, valid;
	u8 state;

	do {
		ret = i2c_master_recv(client, buf, MAX_I2C_DATA_LEN);
	} while (ret == -EAGAIN && tries++ < EGALAX_MAX_TRIES);

	if (ret < 0)
		return IRQ_HANDLED;

	if (buf[0] != REPORT_MODE_MTTOUCH) {
		/* ignore mouse events and vendor events */
		return IRQ_HANDLED;
	}

	state = buf[1];
	x = (buf[3] << 8) | buf[2];
	y = (buf[5] << 8) | buf[4];
	z = (buf[7] << 8) | buf[6];

	valid = state & EVENT_VALID_MASK;
	id = (state & EVENT_ID_MASK) >> EVENT_ID_OFFSET;
	down = state & EVENT_DOWN_UP;

	if (!valid || id > MAX_SUPPORT_POINTS) {
		dev_dbg(&client->dev, "point invalid\n");
		return IRQ_HANDLED;
	}

	input_mt_slot(input_dev, id);
	input_mt_report_slot_state(input_dev, MT_TOOL_FINGER, down);

	dev_dbg(&client->dev, "%s id:%d x:%d y:%d z:%d",
		down ? "down" : "up", id, x, y, z);

	if (down) {
		input_report_abs(input_dev, ABS_MT_POSITION_X, x);
		input_report_abs(input_dev, ABS_MT_POSITION_Y, y);
		input_report_abs(input_dev, ABS_MT_PRESSURE, z);
	}

	input_mt_report_pointer_emulation(input_dev, true);
	input_sync(input_dev);

	return IRQ_HANDLED;
}

/* wake up controller by an falling edge of interrupt gpio.  */
static int egalax_wake_up_device(struct i2c_client *client)
{
	int gpio = irq_to_gpio(client->irq);
	int ret;

	ret = gpio_request(gpio, "egalax_irq");
	if (ret < 0) {
		dev_err(&client->dev,
			"request gpio failed, cannot wake up controller: %d\n",
			ret);
		return ret;
	}

	/* wake up controller via an falling edge on IRQ gpio. */
	gpio_direction_output(gpio, 0);
	gpio_set_value(gpio, 1);

	/* controller should be waken up, return irq.  */
	gpio_direction_input(gpio);
	gpio_free(gpio);

	return 0;
}

static int __devinit egalax_firmware_version(struct i2c_client *client)
{
	static const u8 cmd[MAX_I2C_DATA_LEN] = { 0x03, 0x03, 0xa, 0x01, 0x41 };
	int ret;

	ret = i2c_master_send(client, cmd, MAX_I2C_DATA_LEN);
	if (ret < 0)
		return ret;

	return 0;
}

static int __devinit egalax_ts_probe(struct i2c_client *client,
				       const struct i2c_device_id *id)
{
	struct egalax_ts *ts;
	struct input_dev *input_dev;
	int ret;
	int error;

	ts = kzalloc(sizeof(struct egalax_ts), GFP_KERNEL);
	if (!ts) {
		dev_err(&client->dev, "Failed to allocate memory\n");
		return -ENOMEM;
	}

	input_dev = input_allocate_device();
	if (!input_dev) {
		dev_err(&client->dev, "Failed to allocate memory\n");
		error = -ENOMEM;
		goto err_free_ts;
	}

	ts->client = client;
	ts->input_dev = input_dev;

	/* controller may be in sleep, wake it up. */
	egalax_wake_up_device(client);

	ret = egalax_firmware_version(client);
	if (ret < 0) {
		dev_err(&client->dev, "Failed to read firmware version\n");
		error = -EIO;
		goto err_free_dev;
	}

	input_dev->name = "EETI eGalax Touch Screen";
	input_dev->id.bustype = BUS_I2C;
	input_dev->dev.parent = &client->dev;

	__set_bit(EV_ABS, input_dev->evbit);
	__set_bit(EV_KEY, input_dev->evbit);
	__set_bit(BTN_TOUCH, input_dev->keybit);

	input_set_abs_params(input_dev, ABS_X, 0, EGALAX_MAX_X, 0, 0);
	input_set_abs_params(input_dev, ABS_Y, 0, EGALAX_MAX_Y, 0, 0);
	input_set_abs_params(input_dev,
			     ABS_MT_POSITION_X, 0, EGALAX_MAX_X, 0, 0);
	input_set_abs_params(input_dev,
			     ABS_MT_POSITION_X, 0, EGALAX_MAX_Y, 0, 0);
	input_mt_init_slots(input_dev, MAX_SUPPORT_POINTS);

	input_set_drvdata(input_dev, ts);

	error = request_threaded_irq(client->irq, NULL, egalax_ts_interrupt,
				     IRQF_TRIGGER_LOW | IRQF_ONESHOT,
				     "egalax_ts", ts);
	if (error < 0) {
		dev_err(&client->dev, "Failed to register interrupt\n");
		goto err_free_dev;
	}

	error = input_register_device(ts->input_dev);
	if (error)
		goto err_free_irq;

	i2c_set_clientdata(client, ts);
	return 0;

err_free_irq:
	free_irq(client->irq, ts);
err_free_dev:
	input_free_device(input_dev);
err_free_ts:
	kfree(ts);

	return error;
}

static __devexit int egalax_ts_remove(struct i2c_client *client)
{
	struct egalax_ts *ts = i2c_get_clientdata(client);

	free_irq(client->irq, ts);

	input_unregister_device(ts->input_dev);
	kfree(ts);

	return 0;
}

static const struct i2c_device_id egalax_ts_id[] = {
	{ "egalax_ts", 0 },
	{ }
};
MODULE_DEVICE_TABLE(i2c, egalax_ts_id);

#ifdef CONFIG_PM_SLEEP
static int egalax_ts_suspend(struct device *dev)
{
	static const u8 suspend_cmd[MAX_I2C_DATA_LEN] = {
		0x3, 0x6, 0xa, 0x3, 0x36, 0x3f, 0x2, 0, 0, 0
	};
	struct i2c_client *client = to_i2c_client(dev);
	int ret;

	ret = i2c_master_send(client, suspend_cmd, MAX_I2C_DATA_LEN);
	return ret > 0 ? 0 : ret;
}

static int egalax_ts_resume(struct device *dev)
{
	struct i2c_client *client = to_i2c_client(dev);

	return egalax_wake_up_device(client);
}
#endif

static SIMPLE_DEV_PM_OPS(egalax_ts_pm_ops, egalax_ts_suspend, egalax_ts_resume);

static struct i2c_driver egalax_ts_driver = {
	.driver = {
		.name	= "egalax_ts",
		.owner	= THIS_MODULE,
		.pm	= &egalax_ts_pm_ops,
	},
	.id_table	= egalax_ts_id,
	.probe		= egalax_ts_probe,
	.remove		= __devexit_p(egalax_ts_remove),
};

static int __init egalax_ts_init(void)
{
	return i2c_add_driver(&egalax_ts_driver);
}

static void __exit egalax_ts_exit(void)
{
	i2c_del_driver(&egalax_ts_driver);
}

module_init(egalax_ts_init);
module_exit(egalax_ts_exit);

MODULE_AUTHOR("Freescale Semiconductor, Inc.");
MODULE_DESCRIPTION("Touchscreen driver for EETI eGalax touch controller");
MODULE_LICENSE("GPL");
OpenPOWER on IntegriCloud