summaryrefslogtreecommitdiff
path: root/drivers/input/touchscreen/eeti_ts.c
blob: a2d9a65e586d23aa537f698f17688370e88bcb62 (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
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
/*
 * Touch Screen driver for EETI's I2C connected touch screen panels
 *   Copyright (c) 2009 Daniel Mack <daniel@caiaq.de>
 *
 * See EETI's software guide for the protocol specification:
 *   http://home.eeti.com.tw/web20/eg/guide.htm
 *
 * Based on migor_ts.c
 *   Copyright (c) 2008 Magnus Damm
 *   Copyright (c) 2007 Ujjwal Pande <ujjwal@kenati.com>
 *
 * This file is free software; you can redistribute it and/or
 * modify it under the terms of the GNU  General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This file is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *  General Public License for more details.
 *
 * You should have received a copy of the GNU General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/kernel.h>
#include <linux/input.h>
#include <linux/interrupt.h>
#include <linux/i2c.h>
#include <linux/timer.h>
#include <linux/gpio.h>
#include <linux/input/eeti_ts.h>
#include <linux/slab.h>

static bool flip_x;
module_param(flip_x, bool, 0644);
MODULE_PARM_DESC(flip_x, "flip x coordinate");

static bool flip_y;
module_param(flip_y, bool, 0644);
MODULE_PARM_DESC(flip_y, "flip y coordinate");

struct eeti_ts_priv {
	struct i2c_client *client;
	struct input_dev *input;
	struct work_struct work;
	struct mutex mutex;
	int irq_gpio, irq, irq_active_high;
};

#define EETI_TS_BITDEPTH	(11)
#define EETI_MAXVAL		((1 << (EETI_TS_BITDEPTH + 1)) - 1)

#define REPORT_BIT_PRESSED	(1 << 0)
#define REPORT_BIT_AD0		(1 << 1)
#define REPORT_BIT_AD1		(1 << 2)
#define REPORT_BIT_HAS_PRESSURE	(1 << 6)
#define REPORT_RES_BITS(v)	(((v) >> 1) + EETI_TS_BITDEPTH)

static inline int eeti_ts_irq_active(struct eeti_ts_priv *priv)
{
	return gpio_get_value(priv->irq_gpio) == priv->irq_active_high;
}

static void eeti_ts_read(struct work_struct *work)
{
	char buf[6];
	unsigned int x, y, res, pressed, to = 100;
	struct eeti_ts_priv *priv =
		container_of(work, struct eeti_ts_priv, work);

	mutex_lock(&priv->mutex);

	while (eeti_ts_irq_active(priv) && --to)
		i2c_master_recv(priv->client, buf, sizeof(buf));

	if (!to) {
		dev_err(&priv->client->dev,
			"unable to clear IRQ - line stuck?\n");
		goto out;
	}

	/* drop non-report packets */
	if (!(buf[0] & 0x80))
		goto out;

	pressed = buf[0] & REPORT_BIT_PRESSED;
	res = REPORT_RES_BITS(buf[0] & (REPORT_BIT_AD0 | REPORT_BIT_AD1));
	x = buf[2] | (buf[1] << 8);
	y = buf[4] | (buf[3] << 8);

	/* fix the range to 11 bits */
	x >>= res - EETI_TS_BITDEPTH;
	y >>= res - EETI_TS_BITDEPTH;

	if (flip_x)
		x = EETI_MAXVAL - x;

	if (flip_y)
		y = EETI_MAXVAL - y;

	if (buf[0] & REPORT_BIT_HAS_PRESSURE)
		input_report_abs(priv->input, ABS_PRESSURE, buf[5]);

	input_report_abs(priv->input, ABS_X, x);
	input_report_abs(priv->input, ABS_Y, y);
	input_report_key(priv->input, BTN_TOUCH, !!pressed);
	input_sync(priv->input);

out:
	mutex_unlock(&priv->mutex);
}

static irqreturn_t eeti_ts_isr(int irq, void *dev_id)
{
	struct eeti_ts_priv *priv = dev_id;

	 /* postpone I2C transactions as we are atomic */
	schedule_work(&priv->work);

	return IRQ_HANDLED;
}

static void eeti_ts_start(struct eeti_ts_priv *priv)
{
	enable_irq(priv->irq);

	/* Read the events once to arm the IRQ */
	eeti_ts_read(&priv->work);
}

static void eeti_ts_stop(struct eeti_ts_priv *priv)
{
	disable_irq(priv->irq);
	cancel_work_sync(&priv->work);
}

static int eeti_ts_open(struct input_dev *dev)
{
	struct eeti_ts_priv *priv = input_get_drvdata(dev);

	eeti_ts_start(priv);

	return 0;
}

static void eeti_ts_close(struct input_dev *dev)
{
	struct eeti_ts_priv *priv = input_get_drvdata(dev);

	eeti_ts_stop(priv);
}

static int __devinit eeti_ts_probe(struct i2c_client *client,
				   const struct i2c_device_id *idp)
{
	struct eeti_ts_platform_data *pdata = client->dev.platform_data;
	struct eeti_ts_priv *priv;
	struct input_dev *input;
	unsigned int irq_flags;
	int err = -ENOMEM;

	/*
	 * In contrast to what's described in the datasheet, there seems
	 * to be no way of probing the presence of that device using I2C
	 * commands. So we need to blindly believe it is there, and wait
	 * for interrupts to occur.
	 */

	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
	if (!priv) {
		dev_err(&client->dev, "failed to allocate driver data\n");
		goto err0;
	}

	mutex_init(&priv->mutex);
	input = input_allocate_device();

	if (!input) {
		dev_err(&client->dev, "Failed to allocate input device.\n");
		goto err1;
	}

	input->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
	input->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);

	input_set_abs_params(input, ABS_X, 0, EETI_MAXVAL, 0, 0);
	input_set_abs_params(input, ABS_Y, 0, EETI_MAXVAL, 0, 0);
	input_set_abs_params(input, ABS_PRESSURE, 0, 0xff, 0, 0);

	input->name = client->name;
	input->id.bustype = BUS_I2C;
	input->dev.parent = &client->dev;
	input->open = eeti_ts_open;
	input->close = eeti_ts_close;

	priv->client = client;
	priv->input = input;
	priv->irq_gpio = pdata->irq_gpio;
	priv->irq = gpio_to_irq(pdata->irq_gpio);

	err = gpio_request_one(pdata->irq_gpio, GPIOF_IN, client->name);
	if (err < 0)
		goto err1;

	if (pdata)
		priv->irq_active_high = pdata->irq_active_high;

	irq_flags = priv->irq_active_high ?
		IRQF_TRIGGER_RISING : IRQF_TRIGGER_FALLING;

	INIT_WORK(&priv->work, eeti_ts_read);
	i2c_set_clientdata(client, priv);
	input_set_drvdata(input, priv);

	err = input_register_device(input);
	if (err)
		goto err2;

	err = request_irq(priv->irq, eeti_ts_isr, irq_flags,
			  client->name, priv);
	if (err) {
		dev_err(&client->dev, "Unable to request touchscreen IRQ.\n");
		goto err3;
	}

	/*
	 * Disable the device for now. It will be enabled once the
	 * input device is opened.
	 */
	eeti_ts_stop(priv);

	device_init_wakeup(&client->dev, 0);
	return 0;

err3:
	input_unregister_device(input);
	input = NULL; /* so we dont try to free it below */
err2:
	gpio_free(pdata->irq_gpio);
err1:
	input_free_device(input);
	kfree(priv);
err0:
	return err;
}

static int __devexit eeti_ts_remove(struct i2c_client *client)
{
	struct eeti_ts_priv *priv = i2c_get_clientdata(client);

	free_irq(priv->irq, priv);
	/*
	 * eeti_ts_stop() leaves IRQ disabled. We need to re-enable it
	 * so that device still works if we reload the driver.
	 */
	enable_irq(priv->irq);

	input_unregister_device(priv->input);
	kfree(priv);

	return 0;
}

#ifdef CONFIG_PM
static int eeti_ts_suspend(struct device *dev)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct eeti_ts_priv *priv = i2c_get_clientdata(client);
	struct input_dev *input_dev = priv->input;

	mutex_lock(&input_dev->mutex);

	if (input_dev->users)
		eeti_ts_stop(priv);

	mutex_unlock(&input_dev->mutex);

	if (device_may_wakeup(&client->dev))
		enable_irq_wake(priv->irq);

	return 0;
}

static int eeti_ts_resume(struct device *dev)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct eeti_ts_priv *priv = i2c_get_clientdata(client);
	struct input_dev *input_dev = priv->input;

	if (device_may_wakeup(&client->dev))
		disable_irq_wake(priv->irq);

	mutex_lock(&input_dev->mutex);

	if (input_dev->users)
		eeti_ts_start(priv);

	mutex_unlock(&input_dev->mutex);

	return 0;
}

static SIMPLE_DEV_PM_OPS(eeti_ts_pm, eeti_ts_suspend, eeti_ts_resume);
#endif

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

static struct i2c_driver eeti_ts_driver = {
	.driver = {
		.name = "eeti_ts",
#ifdef CONFIG_PM
		.pm = &eeti_ts_pm,
#endif
	},
	.probe = eeti_ts_probe,
	.remove = eeti_ts_remove,
	.id_table = eeti_ts_id,
};

module_i2c_driver(eeti_ts_driver);

MODULE_DESCRIPTION("EETI Touchscreen driver");
MODULE_AUTHOR("Daniel Mack <daniel@caiaq.de>");
MODULE_LICENSE("GPL");