summaryrefslogtreecommitdiffstats
path: root/drivers/input/touchscreen/imagis.c
blob: 07111ca2445561702980070c2afe0655919bd808 (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
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
// SPDX-License-Identifier: GPL-2.0-only

#include <linux/bits.h>
#include <linux/delay.h>
#include <linux/i2c.h>
#include <linux/input.h>
#include <linux/input/mt.h>
#include <linux/input/touchscreen.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/property.h>
#include <linux/regulator/consumer.h>

#define IST3038C_HIB_ACCESS		(0x800B << 16)
#define IST3038C_DIRECT_ACCESS		BIT(31)
#define IST3038C_REG_CHIPID		0x40001000
#define IST3038C_REG_HIB_BASE		0x30000100
#define IST3038C_REG_TOUCH_STATUS	(IST3038C_REG_HIB_BASE | IST3038C_HIB_ACCESS)
#define IST3038C_REG_TOUCH_COORD	(IST3038C_REG_HIB_BASE | IST3038C_HIB_ACCESS | 0x8)
#define IST3038C_REG_INTR_MESSAGE	(IST3038C_REG_HIB_BASE | IST3038C_HIB_ACCESS | 0x4)
#define IST3038C_WHOAMI			0x38c
#define IST3038C_CHIP_ON_DELAY_MS	60
#define IST3038C_I2C_RETRY_COUNT	3
#define IST3038C_MAX_FINGER_NUM		10
#define IST3038C_X_MASK			GENMASK(23, 12)
#define IST3038C_X_SHIFT		12
#define IST3038C_Y_MASK			GENMASK(11, 0)
#define IST3038C_AREA_MASK		GENMASK(27, 24)
#define IST3038C_AREA_SHIFT		24
#define IST3038C_FINGER_COUNT_MASK	GENMASK(15, 12)
#define IST3038C_FINGER_COUNT_SHIFT	12
#define IST3038C_FINGER_STATUS_MASK	GENMASK(9, 0)

struct imagis_ts {
	struct i2c_client *client;
	struct input_dev *input_dev;
	struct touchscreen_properties prop;
	struct regulator_bulk_data supplies[2];
};

static int imagis_i2c_read_reg(struct imagis_ts *ts,
			       unsigned int reg, u32 *data)
{
	__be32 ret_be;
	__be32 reg_be = cpu_to_be32(reg);
	struct i2c_msg msg[] = {
		{
			.addr = ts->client->addr,
			.flags = 0,
			.buf = (unsigned char *)&reg_be,
			.len = sizeof(reg_be),
		}, {
			.addr = ts->client->addr,
			.flags = I2C_M_RD,
			.buf = (unsigned char *)&ret_be,
			.len = sizeof(ret_be),
		},
	};
	int ret, error;
	int retry = IST3038C_I2C_RETRY_COUNT;

	/* Retry in case the controller fails to respond */
	do {
		ret = i2c_transfer(ts->client->adapter, msg, ARRAY_SIZE(msg));
		if (ret == ARRAY_SIZE(msg)) {
			*data = be32_to_cpu(ret_be);
			return 0;
		}

		error = ret < 0 ? ret : -EIO;
		dev_err(&ts->client->dev,
			"%s - i2c_transfer failed: %d (%d)\n",
			__func__, error, ret);
	} while (--retry);

	return error;
}

static irqreturn_t imagis_interrupt(int irq, void *dev_id)
{
	struct imagis_ts *ts = dev_id;
	u32 intr_message, finger_status;
	unsigned int finger_count, finger_pressed;
	int i;
	int error;

	error = imagis_i2c_read_reg(ts, IST3038C_REG_INTR_MESSAGE,
				    &intr_message);
	if (error) {
		dev_err(&ts->client->dev,
			"failed to read the interrupt message: %d\n", error);
		goto out;
	}

	finger_count = (intr_message & IST3038C_FINGER_COUNT_MASK) >>
				IST3038C_FINGER_COUNT_SHIFT;
	if (finger_count > IST3038C_MAX_FINGER_NUM) {
		dev_err(&ts->client->dev,
			"finger count %d is more than maximum supported\n",
			finger_count);
		goto out;
	}

	finger_pressed = intr_message & IST3038C_FINGER_STATUS_MASK;

	for (i = 0; i < finger_count; i++) {
		error = imagis_i2c_read_reg(ts,
					    IST3038C_REG_TOUCH_COORD + (i * 4),
					    &finger_status);
		if (error) {
			dev_err(&ts->client->dev,
				"failed to read coordinates for finger %d: %d\n",
				i, error);
			goto out;
		}

		input_mt_slot(ts->input_dev, i);
		input_mt_report_slot_state(ts->input_dev, MT_TOOL_FINGER,
					   finger_pressed & BIT(i));
		touchscreen_report_pos(ts->input_dev, &ts->prop,
				       (finger_status & IST3038C_X_MASK) >>
						IST3038C_X_SHIFT,
				       finger_status & IST3038C_Y_MASK, 1);
		input_report_abs(ts->input_dev, ABS_MT_TOUCH_MAJOR,
				 (finger_status & IST3038C_AREA_MASK) >>
					IST3038C_AREA_SHIFT);
	}

	input_mt_sync_frame(ts->input_dev);
	input_sync(ts->input_dev);

out:
	return IRQ_HANDLED;
}

static void imagis_power_off(void *_ts)
{
	struct imagis_ts *ts = _ts;

	regulator_bulk_disable(ARRAY_SIZE(ts->supplies), ts->supplies);
}

static int imagis_power_on(struct imagis_ts *ts)
{
	int error;

	error = regulator_bulk_enable(ARRAY_SIZE(ts->supplies), ts->supplies);
	if (error)
		return error;

	msleep(IST3038C_CHIP_ON_DELAY_MS);

	return 0;
}

static int imagis_start(struct imagis_ts *ts)
{
	int error;

	error = imagis_power_on(ts);
	if (error)
		return error;

	enable_irq(ts->client->irq);

	return 0;
}

static int imagis_stop(struct imagis_ts *ts)
{
	disable_irq(ts->client->irq);

	imagis_power_off(ts);

	return 0;
}

static int imagis_input_open(struct input_dev *dev)
{
	struct imagis_ts *ts = input_get_drvdata(dev);

	return imagis_start(ts);
}

static void imagis_input_close(struct input_dev *dev)
{
	struct imagis_ts *ts = input_get_drvdata(dev);

	imagis_stop(ts);
}

static int imagis_init_input_dev(struct imagis_ts *ts)
{
	struct input_dev *input_dev;
	int error;

	input_dev = devm_input_allocate_device(&ts->client->dev);
	if (!input_dev)
		return -ENOMEM;

	ts->input_dev = input_dev;

	input_dev->name = "Imagis capacitive touchscreen";
	input_dev->phys = "input/ts";
	input_dev->id.bustype = BUS_I2C;
	input_dev->open = imagis_input_open;
	input_dev->close = imagis_input_close;

	input_set_drvdata(input_dev, ts);

	input_set_capability(input_dev, EV_ABS, ABS_MT_POSITION_X);
	input_set_capability(input_dev, EV_ABS, ABS_MT_POSITION_Y);
	input_set_abs_params(input_dev, ABS_MT_TOUCH_MAJOR, 0, 255, 0, 0);

	touchscreen_parse_properties(input_dev, true, &ts->prop);
	if (!ts->prop.max_x || !ts->prop.max_y) {
		dev_err(&ts->client->dev,
			"Touchscreen-size-x and/or touchscreen-size-y not set in dts\n");
		return -EINVAL;
	}

	error = input_mt_init_slots(input_dev,
				    IST3038C_MAX_FINGER_NUM,
				    INPUT_MT_DIRECT | INPUT_MT_DROP_UNUSED);
	if (error) {
		dev_err(&ts->client->dev,
			"Failed to initialize MT slots: %d", error);
		return error;
	}

	error = input_register_device(input_dev);
	if (error) {
		dev_err(&ts->client->dev,
			"Failed to register input device: %d", error);
		return error;
	}

	return 0;
}

static int imagis_init_regulators(struct imagis_ts *ts)
{
	struct i2c_client *client = ts->client;

	ts->supplies[0].supply = "vdd";
	ts->supplies[1].supply = "vddio";
	return devm_regulator_bulk_get(&client->dev,
				       ARRAY_SIZE(ts->supplies),
				       ts->supplies);
}

static int imagis_probe(struct i2c_client *i2c)
{
	struct device *dev = &i2c->dev;
	struct imagis_ts *ts;
	int chip_id, error;

	ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL);
	if (!ts)
		return -ENOMEM;

	ts->client = i2c;

	error = imagis_init_regulators(ts);
	if (error) {
		dev_err(dev, "regulator init error: %d\n", error);
		return error;
	}

	error = imagis_power_on(ts);
	if (error) {
		dev_err(dev, "failed to enable regulators: %d\n", error);
		return error;
	}

	error = devm_add_action_or_reset(dev, imagis_power_off, ts);
	if (error) {
		dev_err(dev, "failed to install poweroff action: %d\n", error);
		return error;
	}

	error = imagis_i2c_read_reg(ts,
			IST3038C_REG_CHIPID | IST3038C_DIRECT_ACCESS,
			&chip_id);
	if (error) {
		dev_err(dev, "chip ID read failure: %d\n", error);
		return error;
	}

	if (chip_id != IST3038C_WHOAMI) {
		dev_err(dev, "unknown chip ID: 0x%x\n", chip_id);
		return -EINVAL;
	}

	error = devm_request_threaded_irq(dev, i2c->irq,
					  NULL, imagis_interrupt,
					  IRQF_ONESHOT | IRQF_NO_AUTOEN,
					  "imagis-touchscreen", ts);
	if (error) {
		dev_err(dev, "IRQ %d allocation failure: %d\n",
			i2c->irq, error);
		return error;
	}

	error = imagis_init_input_dev(ts);
	if (error)
		return error;

	return 0;
}

static int imagis_suspend(struct device *dev)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct imagis_ts *ts = i2c_get_clientdata(client);
	int retval = 0;

	mutex_lock(&ts->input_dev->mutex);

	if (input_device_enabled(ts->input_dev))
		retval = imagis_stop(ts);

	mutex_unlock(&ts->input_dev->mutex);

	return retval;
}

static int imagis_resume(struct device *dev)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct imagis_ts *ts = i2c_get_clientdata(client);
	int retval = 0;

	mutex_lock(&ts->input_dev->mutex);

	if (input_device_enabled(ts->input_dev))
		retval = imagis_start(ts);

	mutex_unlock(&ts->input_dev->mutex);

	return retval;
}

static DEFINE_SIMPLE_DEV_PM_OPS(imagis_pm_ops, imagis_suspend, imagis_resume);

#ifdef CONFIG_OF
static const struct of_device_id imagis_of_match[] = {
	{ .compatible = "imagis,ist3038c", },
	{ },
};
MODULE_DEVICE_TABLE(of, imagis_of_match);
#endif

static struct i2c_driver imagis_ts_driver = {
	.driver = {
		.name = "imagis-touchscreen",
		.pm = pm_sleep_ptr(&imagis_pm_ops),
		.of_match_table = of_match_ptr(imagis_of_match),
	},
	.probe = imagis_probe,
};

module_i2c_driver(imagis_ts_driver);

MODULE_DESCRIPTION("Imagis IST3038C Touchscreen Driver");
MODULE_AUTHOR("Markuss Broks <markuss.broks@gmail.com>");
MODULE_LICENSE("GPL");