summaryrefslogtreecommitdiff
path: root/drivers/input/touchscreen/tps6507x-ts.c
blob: f488717677636a73ce4aab6e9acf918f209c1899 (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
/*
 * Touchscreen driver for the tps6507x chip.
 *
 * Copyright (c) 2009 RidgeRun (todd.fischer@ridgerun.com)
 *
 * Credits:
 *
 *    Using code from tsc2007, MtekVision Co., Ltd.
 *
 * For licencing details see kernel-base/COPYING
 *
 * TPS65070, TPS65073, TPS650731, and TPS650732 support
 * 10 bit touch screen interface.
 */

#include <linux/module.h>
#include <linux/workqueue.h>
#include <linux/slab.h>
#include <linux/input.h>
#include <linux/platform_device.h>
#include <linux/mfd/tps6507x.h>
#include <linux/input/tps6507x-ts.h>
#include <linux/delay.h>

#define TSC_DEFAULT_POLL_PERIOD 30 /* ms */
#define TPS_DEFAULT_MIN_PRESSURE 0x30
#define MAX_10BIT ((1 << 10) - 1)

#define	TPS6507X_ADCONFIG_CONVERT_TS (TPS6507X_ADCONFIG_AD_ENABLE | \
					 TPS6507X_ADCONFIG_START_CONVERSION | \
					 TPS6507X_ADCONFIG_INPUT_REAL_TSC)
#define	TPS6507X_ADCONFIG_POWER_DOWN_TS (TPS6507X_ADCONFIG_INPUT_REAL_TSC)

struct ts_event {
	u16	x;
	u16	y;
	u16	pressure;
};

struct tps6507x_ts {
	struct device		*dev;
	struct input_dev	*input;
	struct tps6507x_dev	*mfd;
	char			phys[32];
	struct ts_event		tc;
	u16			min_pressure;
	bool			pendown;
};

static int tps6507x_read_u8(struct tps6507x_ts *tsc, u8 reg, u8 *data)
{
	return tsc->mfd->read_dev(tsc->mfd, reg, 1, data);
}

static int tps6507x_write_u8(struct tps6507x_ts *tsc, u8 reg, u8 data)
{
	return tsc->mfd->write_dev(tsc->mfd, reg, 1, &data);
}

static s32 tps6507x_adc_conversion(struct tps6507x_ts *tsc,
				   u8 tsc_mode, u16 *value)
{
	s32 ret;
	u8 adc_status;
	u8 result;

	/* Route input signal to A/D converter */

	ret = tps6507x_write_u8(tsc, TPS6507X_REG_TSCMODE, tsc_mode);
	if (ret) {
		dev_err(tsc->dev, "TSC mode read failed\n");
		goto err;
	}

	/* Start A/D conversion */

	ret = tps6507x_write_u8(tsc, TPS6507X_REG_ADCONFIG,
				TPS6507X_ADCONFIG_CONVERT_TS);
	if (ret) {
		dev_err(tsc->dev, "ADC config write failed\n");
		return ret;
	}

	do {
		ret = tps6507x_read_u8(tsc, TPS6507X_REG_ADCONFIG,
				       &adc_status);
		if (ret) {
			dev_err(tsc->dev, "ADC config read failed\n");
			goto err;
		}
	} while (adc_status & TPS6507X_ADCONFIG_START_CONVERSION);

	ret = tps6507x_read_u8(tsc, TPS6507X_REG_ADRESULT_2, &result);
	if (ret) {
		dev_err(tsc->dev, "ADC result 2 read failed\n");
		goto err;
	}

	*value = (result & TPS6507X_REG_ADRESULT_2_MASK) << 8;

	ret = tps6507x_read_u8(tsc, TPS6507X_REG_ADRESULT_1, &result);
	if (ret) {
		dev_err(tsc->dev, "ADC result 1 read failed\n");
		goto err;
	}

	*value |= result;

	dev_dbg(tsc->dev, "TSC channel %d = 0x%X\n", tsc_mode, *value);

err:
	return ret;
}

/* Need to call tps6507x_adc_standby() after using A/D converter for the
 * touch screen interrupt to work properly.
 */

static s32 tps6507x_adc_standby(struct tps6507x_ts *tsc)
{
	s32 ret;
	u8 val;

	ret = tps6507x_write_u8(tsc,  TPS6507X_REG_ADCONFIG,
				TPS6507X_ADCONFIG_INPUT_TSC);
	if (ret)
		return ret;

	ret = tps6507x_write_u8(tsc, TPS6507X_REG_TSCMODE,
				TPS6507X_TSCMODE_STANDBY);
	if (ret)
		return ret;

	ret = tps6507x_read_u8(tsc, TPS6507X_REG_INT, &val);
	if (ret)
		return ret;

	while (val & TPS6507X_REG_TSC_INT) {
		mdelay(10);
		ret = tps6507x_read_u8(tsc, TPS6507X_REG_INT, &val);
		if (ret)
			return ret;
	}

	return ret;
}

static void tps6507x_ts_poll(struct input_dev *input_dev)
{
	struct tps6507x_ts *tsc = input_get_drvdata(input_dev);
	bool pendown;
	s32 ret;

	ret = tps6507x_adc_conversion(tsc, TPS6507X_TSCMODE_PRESSURE,
				      &tsc->tc.pressure);
	if (ret)
		goto done;

	pendown = tsc->tc.pressure > tsc->min_pressure;

	if (unlikely(!pendown && tsc->pendown)) {
		dev_dbg(tsc->dev, "UP\n");
		input_report_key(input_dev, BTN_TOUCH, 0);
		input_report_abs(input_dev, ABS_PRESSURE, 0);
		input_sync(input_dev);
		tsc->pendown = false;
	}

	if (pendown) {

		if (!tsc->pendown) {
			dev_dbg(tsc->dev, "DOWN\n");
			input_report_key(input_dev, BTN_TOUCH, 1);
		} else
			dev_dbg(tsc->dev, "still down\n");

		ret =  tps6507x_adc_conversion(tsc, TPS6507X_TSCMODE_X_POSITION,
					       &tsc->tc.x);
		if (ret)
			goto done;

		ret =  tps6507x_adc_conversion(tsc, TPS6507X_TSCMODE_Y_POSITION,
					       &tsc->tc.y);
		if (ret)
			goto done;

		input_report_abs(input_dev, ABS_X, tsc->tc.x);
		input_report_abs(input_dev, ABS_Y, tsc->tc.y);
		input_report_abs(input_dev, ABS_PRESSURE, tsc->tc.pressure);
		input_sync(input_dev);
		tsc->pendown = true;
	}

done:
	tps6507x_adc_standby(tsc);
}

static int tps6507x_ts_probe(struct platform_device *pdev)
{
	struct tps6507x_dev *tps6507x_dev = dev_get_drvdata(pdev->dev.parent);
	const struct tps6507x_board *tps_board;
	const struct touchscreen_init_data *init_data;
	struct tps6507x_ts *tsc;
	struct input_dev *input_dev;
	int error;

	/*
	 * tps_board points to pmic related constants
	 * coming from the board-evm file.
	 */
	tps_board = dev_get_platdata(tps6507x_dev->dev);
	if (!tps_board) {
		dev_err(tps6507x_dev->dev,
			"Could not find tps6507x platform data\n");
		return -ENODEV;
	}

	/*
	 * init_data points to array of regulator_init structures
	 * coming from the board-evm file.
	 */
	init_data = tps_board->tps6507x_ts_init_data;

	tsc = devm_kzalloc(&pdev->dev, sizeof(struct tps6507x_ts), GFP_KERNEL);
	if (!tsc) {
		dev_err(tps6507x_dev->dev, "failed to allocate driver data\n");
		return -ENOMEM;
	}

	tsc->mfd = tps6507x_dev;
	tsc->dev = tps6507x_dev->dev;
	tsc->min_pressure = init_data ?
			init_data->min_pressure : TPS_DEFAULT_MIN_PRESSURE;

	snprintf(tsc->phys, sizeof(tsc->phys),
		 "%s/input0", dev_name(tsc->dev));

	input_dev = devm_input_allocate_device(&pdev->dev);
	if (!input_dev) {
		dev_err(tsc->dev, "Failed to allocate polled input device.\n");
		return -ENOMEM;
	}

	tsc->input = input_dev;
	input_set_drvdata(input_dev, tsc);

	input_set_capability(input_dev, EV_KEY, BTN_TOUCH);
	input_set_abs_params(input_dev, ABS_X, 0, MAX_10BIT, 0, 0);
	input_set_abs_params(input_dev, ABS_Y, 0, MAX_10BIT, 0, 0);
	input_set_abs_params(input_dev, ABS_PRESSURE, 0, MAX_10BIT, 0, 0);

	input_dev->name = "TPS6507x Touchscreen";
	input_dev->phys = tsc->phys;
	input_dev->dev.parent = tsc->dev;
	input_dev->id.bustype = BUS_I2C;
	if (init_data) {
		input_dev->id.vendor = init_data->vendor;
		input_dev->id.product = init_data->product;
		input_dev->id.version = init_data->version;
	}

	error = tps6507x_adc_standby(tsc);
	if (error)
		return error;

	error = input_setup_polling(input_dev, tps6507x_ts_poll);
	if (error)
		return error;

	input_set_poll_interval(input_dev,
				init_data ? init_data->poll_period :
					    TSC_DEFAULT_POLL_PERIOD);

	error = input_register_device(input_dev);
	if (error)
		return error;

	return 0;
}

static struct platform_driver tps6507x_ts_driver = {
	.driver = {
		.name = "tps6507x-ts",
	},
	.probe = tps6507x_ts_probe,
};
module_platform_driver(tps6507x_ts_driver);

MODULE_AUTHOR("Todd Fischer <todd.fischer@ridgerun.com>");
MODULE_DESCRIPTION("TPS6507x - TouchScreen driver");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:tps6507x-ts");