summaryrefslogtreecommitdiff
path: root/drivers/input/touchscreen/pcap_ts.c
blob: 23a354a392aed7ab259bf3d8f0a53203dbab28b7 (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
/*
 * Driver for Motorola PCAP2 touchscreen as found in the EZX phone platform.
 *
 *  Copyright (C) 2006 Harald Welte <laforge@openezx.org>
 *  Copyright (C) 2009 Daniel Ribeiro <drwyrm@gmail.com>
 *
 *  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.
 *
 */

#include <linux/module.h>
#include <linux/fs.h>
#include <linux/string.h>
#include <linux/slab.h>
#include <linux/pm.h>
#include <linux/timer.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>
#include <linux/input.h>
#include <linux/mfd/ezx-pcap.h>

struct pcap_ts {
	struct pcap_chip *pcap;
	struct input_dev *input;
	struct delayed_work work;
	u16 x, y;
	u16 pressure;
	u8 read_state;
};

#define SAMPLE_DELAY	20 /* msecs */

#define X_AXIS_MIN	0
#define X_AXIS_MAX	1023
#define Y_AXIS_MAX	X_AXIS_MAX
#define Y_AXIS_MIN	X_AXIS_MIN
#define PRESSURE_MAX	X_AXIS_MAX
#define PRESSURE_MIN	X_AXIS_MIN

static void pcap_ts_read_xy(void *data, u16 res[2])
{
	struct pcap_ts *pcap_ts = data;

	switch (pcap_ts->read_state) {
	case PCAP_ADC_TS_M_PRESSURE:
		/* pressure reading is unreliable */
		if (res[0] > PRESSURE_MIN && res[0] < PRESSURE_MAX)
			pcap_ts->pressure = res[0];
		pcap_ts->read_state = PCAP_ADC_TS_M_XY;
		schedule_delayed_work(&pcap_ts->work, 0);
		break;
	case PCAP_ADC_TS_M_XY:
		pcap_ts->y = res[0];
		pcap_ts->x = res[1];
		if (pcap_ts->x <= X_AXIS_MIN || pcap_ts->x >= X_AXIS_MAX ||
		    pcap_ts->y <= Y_AXIS_MIN || pcap_ts->y >= Y_AXIS_MAX) {
			/* pen has been released */
			input_report_abs(pcap_ts->input, ABS_PRESSURE, 0);
			input_report_key(pcap_ts->input, BTN_TOUCH, 0);

			pcap_ts->read_state = PCAP_ADC_TS_M_STANDBY;
			schedule_delayed_work(&pcap_ts->work, 0);
		} else {
			/* pen is touching the screen */
			input_report_abs(pcap_ts->input, ABS_X, pcap_ts->x);
			input_report_abs(pcap_ts->input, ABS_Y, pcap_ts->y);
			input_report_key(pcap_ts->input, BTN_TOUCH, 1);
			input_report_abs(pcap_ts->input, ABS_PRESSURE,
						pcap_ts->pressure);

			/* switch back to pressure read mode */
			pcap_ts->read_state = PCAP_ADC_TS_M_PRESSURE;
			schedule_delayed_work(&pcap_ts->work,
					msecs_to_jiffies(SAMPLE_DELAY));
		}
		input_sync(pcap_ts->input);
		break;
	default:
		dev_warn(&pcap_ts->input->dev,
				"pcap_ts: Warning, unhandled read_state %d\n",
				pcap_ts->read_state);
		break;
	}
}

static void pcap_ts_work(struct work_struct *work)
{
	struct delayed_work *dw = container_of(work, struct delayed_work, work);
	struct pcap_ts *pcap_ts = container_of(dw, struct pcap_ts, work);
	u8 ch[2];

	pcap_set_ts_bits(pcap_ts->pcap,
			pcap_ts->read_state << PCAP_ADC_TS_M_SHIFT);

	if (pcap_ts->read_state == PCAP_ADC_TS_M_STANDBY)
		return;

	/* start adc conversion */
	ch[0] = PCAP_ADC_CH_TS_X1;
	ch[1] = PCAP_ADC_CH_TS_Y1;
	pcap_adc_async(pcap_ts->pcap, PCAP_ADC_BANK_1, 0, ch,
						pcap_ts_read_xy, pcap_ts);
}

static irqreturn_t pcap_ts_event_touch(int pirq, void *data)
{
	struct pcap_ts *pcap_ts = data;

	if (pcap_ts->read_state == PCAP_ADC_TS_M_STANDBY) {
		pcap_ts->read_state = PCAP_ADC_TS_M_PRESSURE;
		schedule_delayed_work(&pcap_ts->work, 0);
	}
	return IRQ_HANDLED;
}

static int pcap_ts_open(struct input_dev *dev)
{
	struct pcap_ts *pcap_ts = input_get_drvdata(dev);

	pcap_ts->read_state = PCAP_ADC_TS_M_STANDBY;
	schedule_delayed_work(&pcap_ts->work, 0);

	return 0;
}

static void pcap_ts_close(struct input_dev *dev)
{
	struct pcap_ts *pcap_ts = input_get_drvdata(dev);

	cancel_delayed_work_sync(&pcap_ts->work);

	pcap_ts->read_state = PCAP_ADC_TS_M_NONTS;
	pcap_set_ts_bits(pcap_ts->pcap,
				pcap_ts->read_state << PCAP_ADC_TS_M_SHIFT);
}

static int pcap_ts_probe(struct platform_device *pdev)
{
	struct input_dev *input_dev;
	struct pcap_ts *pcap_ts;
	int err = -ENOMEM;

	pcap_ts = kzalloc(sizeof(*pcap_ts), GFP_KERNEL);
	if (!pcap_ts)
		return err;

	pcap_ts->pcap = dev_get_drvdata(pdev->dev.parent);
	platform_set_drvdata(pdev, pcap_ts);

	input_dev = input_allocate_device();
	if (!input_dev)
		goto fail;

	INIT_DELAYED_WORK(&pcap_ts->work, pcap_ts_work);

	pcap_ts->read_state = PCAP_ADC_TS_M_NONTS;
	pcap_set_ts_bits(pcap_ts->pcap,
				pcap_ts->read_state << PCAP_ADC_TS_M_SHIFT);

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

	input_dev->name = "pcap-touchscreen";
	input_dev->phys = "pcap_ts/input0";
	input_dev->id.bustype = BUS_HOST;
	input_dev->id.vendor = 0x0001;
	input_dev->id.product = 0x0002;
	input_dev->id.version = 0x0100;
	input_dev->dev.parent = &pdev->dev;
	input_dev->open = pcap_ts_open;
	input_dev->close = pcap_ts_close;

	input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
	input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
	input_set_abs_params(input_dev, ABS_X, X_AXIS_MIN, X_AXIS_MAX, 0, 0);
	input_set_abs_params(input_dev, ABS_Y, Y_AXIS_MIN, Y_AXIS_MAX, 0, 0);
	input_set_abs_params(input_dev, ABS_PRESSURE, PRESSURE_MIN,
			     PRESSURE_MAX, 0, 0);

	err = input_register_device(pcap_ts->input);
	if (err)
		goto fail_allocate;

	err = request_irq(pcap_to_irq(pcap_ts->pcap, PCAP_IRQ_TS),
			pcap_ts_event_touch, 0, "Touch Screen", pcap_ts);
	if (err)
		goto fail_register;

	return 0;

fail_register:
	input_unregister_device(input_dev);
	goto fail;
fail_allocate:
	input_free_device(input_dev);
fail:
	kfree(pcap_ts);

	return err;
}

static int pcap_ts_remove(struct platform_device *pdev)
{
	struct pcap_ts *pcap_ts = platform_get_drvdata(pdev);

	free_irq(pcap_to_irq(pcap_ts->pcap, PCAP_IRQ_TS), pcap_ts);
	cancel_delayed_work_sync(&pcap_ts->work);

	input_unregister_device(pcap_ts->input);

	kfree(pcap_ts);

	return 0;
}

#ifdef CONFIG_PM
static int pcap_ts_suspend(struct device *dev)
{
	struct pcap_ts *pcap_ts = dev_get_drvdata(dev);

	pcap_set_ts_bits(pcap_ts->pcap, PCAP_ADC_TS_REF_LOWPWR);
	return 0;
}

static int pcap_ts_resume(struct device *dev)
{
	struct pcap_ts *pcap_ts = dev_get_drvdata(dev);

	pcap_set_ts_bits(pcap_ts->pcap,
				pcap_ts->read_state << PCAP_ADC_TS_M_SHIFT);
	return 0;
}

static const struct dev_pm_ops pcap_ts_pm_ops = {
	.suspend	= pcap_ts_suspend,
	.resume		= pcap_ts_resume,
};
#define PCAP_TS_PM_OPS (&pcap_ts_pm_ops)
#else
#define PCAP_TS_PM_OPS NULL
#endif

static struct platform_driver pcap_ts_driver = {
	.probe		= pcap_ts_probe,
	.remove		= pcap_ts_remove,
	.driver		= {
		.name	= "pcap-ts",
		.pm	= PCAP_TS_PM_OPS,
	},
};
module_platform_driver(pcap_ts_driver);

MODULE_DESCRIPTION("Motorola PCAP2 touchscreen driver");
MODULE_AUTHOR("Daniel Ribeiro / Harald Welte");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:pcap_ts");