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/drivers/input/touchscreen/pcap_ts.c

http://github.com/mirrors/linux
C | 254 lines | 196 code | 46 blank | 12 comment | 15 complexity | 47ec07503491ae6343daff2d14963fee MD5 | raw file
  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * Driver for Motorola PCAP2 touchscreen as found in the EZX phone platform.
  4 *
  5 *  Copyright (C) 2006 Harald Welte <laforge@openezx.org>
  6 *  Copyright (C) 2009 Daniel Ribeiro <drwyrm@gmail.com>
  7 */
  8
  9#include <linux/module.h>
 10#include <linux/fs.h>
 11#include <linux/string.h>
 12#include <linux/slab.h>
 13#include <linux/pm.h>
 14#include <linux/timer.h>
 15#include <linux/interrupt.h>
 16#include <linux/platform_device.h>
 17#include <linux/input.h>
 18#include <linux/mfd/ezx-pcap.h>
 19
 20struct pcap_ts {
 21	struct pcap_chip *pcap;
 22	struct input_dev *input;
 23	struct delayed_work work;
 24	u16 x, y;
 25	u16 pressure;
 26	u8 read_state;
 27};
 28
 29#define SAMPLE_DELAY	20 /* msecs */
 30
 31#define X_AXIS_MIN	0
 32#define X_AXIS_MAX	1023
 33#define Y_AXIS_MAX	X_AXIS_MAX
 34#define Y_AXIS_MIN	X_AXIS_MIN
 35#define PRESSURE_MAX	X_AXIS_MAX
 36#define PRESSURE_MIN	X_AXIS_MIN
 37
 38static void pcap_ts_read_xy(void *data, u16 res[2])
 39{
 40	struct pcap_ts *pcap_ts = data;
 41
 42	switch (pcap_ts->read_state) {
 43	case PCAP_ADC_TS_M_PRESSURE:
 44		/* pressure reading is unreliable */
 45		if (res[0] > PRESSURE_MIN && res[0] < PRESSURE_MAX)
 46			pcap_ts->pressure = res[0];
 47		pcap_ts->read_state = PCAP_ADC_TS_M_XY;
 48		schedule_delayed_work(&pcap_ts->work, 0);
 49		break;
 50	case PCAP_ADC_TS_M_XY:
 51		pcap_ts->y = res[0];
 52		pcap_ts->x = res[1];
 53		if (pcap_ts->x <= X_AXIS_MIN || pcap_ts->x >= X_AXIS_MAX ||
 54		    pcap_ts->y <= Y_AXIS_MIN || pcap_ts->y >= Y_AXIS_MAX) {
 55			/* pen has been released */
 56			input_report_abs(pcap_ts->input, ABS_PRESSURE, 0);
 57			input_report_key(pcap_ts->input, BTN_TOUCH, 0);
 58
 59			pcap_ts->read_state = PCAP_ADC_TS_M_STANDBY;
 60			schedule_delayed_work(&pcap_ts->work, 0);
 61		} else {
 62			/* pen is touching the screen */
 63			input_report_abs(pcap_ts->input, ABS_X, pcap_ts->x);
 64			input_report_abs(pcap_ts->input, ABS_Y, pcap_ts->y);
 65			input_report_key(pcap_ts->input, BTN_TOUCH, 1);
 66			input_report_abs(pcap_ts->input, ABS_PRESSURE,
 67						pcap_ts->pressure);
 68
 69			/* switch back to pressure read mode */
 70			pcap_ts->read_state = PCAP_ADC_TS_M_PRESSURE;
 71			schedule_delayed_work(&pcap_ts->work,
 72					msecs_to_jiffies(SAMPLE_DELAY));
 73		}
 74		input_sync(pcap_ts->input);
 75		break;
 76	default:
 77		dev_warn(&pcap_ts->input->dev,
 78				"pcap_ts: Warning, unhandled read_state %d\n",
 79				pcap_ts->read_state);
 80		break;
 81	}
 82}
 83
 84static void pcap_ts_work(struct work_struct *work)
 85{
 86	struct delayed_work *dw = to_delayed_work(work);
 87	struct pcap_ts *pcap_ts = container_of(dw, struct pcap_ts, work);
 88	u8 ch[2];
 89
 90	pcap_set_ts_bits(pcap_ts->pcap,
 91			pcap_ts->read_state << PCAP_ADC_TS_M_SHIFT);
 92
 93	if (pcap_ts->read_state == PCAP_ADC_TS_M_STANDBY)
 94		return;
 95
 96	/* start adc conversion */
 97	ch[0] = PCAP_ADC_CH_TS_X1;
 98	ch[1] = PCAP_ADC_CH_TS_Y1;
 99	pcap_adc_async(pcap_ts->pcap, PCAP_ADC_BANK_1, 0, ch,
100						pcap_ts_read_xy, pcap_ts);
101}
102
103static irqreturn_t pcap_ts_event_touch(int pirq, void *data)
104{
105	struct pcap_ts *pcap_ts = data;
106
107	if (pcap_ts->read_state == PCAP_ADC_TS_M_STANDBY) {
108		pcap_ts->read_state = PCAP_ADC_TS_M_PRESSURE;
109		schedule_delayed_work(&pcap_ts->work, 0);
110	}
111	return IRQ_HANDLED;
112}
113
114static int pcap_ts_open(struct input_dev *dev)
115{
116	struct pcap_ts *pcap_ts = input_get_drvdata(dev);
117
118	pcap_ts->read_state = PCAP_ADC_TS_M_STANDBY;
119	schedule_delayed_work(&pcap_ts->work, 0);
120
121	return 0;
122}
123
124static void pcap_ts_close(struct input_dev *dev)
125{
126	struct pcap_ts *pcap_ts = input_get_drvdata(dev);
127
128	cancel_delayed_work_sync(&pcap_ts->work);
129
130	pcap_ts->read_state = PCAP_ADC_TS_M_NONTS;
131	pcap_set_ts_bits(pcap_ts->pcap,
132				pcap_ts->read_state << PCAP_ADC_TS_M_SHIFT);
133}
134
135static int pcap_ts_probe(struct platform_device *pdev)
136{
137	struct input_dev *input_dev;
138	struct pcap_ts *pcap_ts;
139	int err = -ENOMEM;
140
141	pcap_ts = kzalloc(sizeof(*pcap_ts), GFP_KERNEL);
142	if (!pcap_ts)
143		return err;
144
145	pcap_ts->pcap = dev_get_drvdata(pdev->dev.parent);
146	platform_set_drvdata(pdev, pcap_ts);
147
148	input_dev = input_allocate_device();
149	if (!input_dev)
150		goto fail;
151
152	INIT_DELAYED_WORK(&pcap_ts->work, pcap_ts_work);
153
154	pcap_ts->read_state = PCAP_ADC_TS_M_NONTS;
155	pcap_set_ts_bits(pcap_ts->pcap,
156				pcap_ts->read_state << PCAP_ADC_TS_M_SHIFT);
157
158	pcap_ts->input = input_dev;
159	input_set_drvdata(input_dev, pcap_ts);
160
161	input_dev->name = "pcap-touchscreen";
162	input_dev->phys = "pcap_ts/input0";
163	input_dev->id.bustype = BUS_HOST;
164	input_dev->id.vendor = 0x0001;
165	input_dev->id.product = 0x0002;
166	input_dev->id.version = 0x0100;
167	input_dev->dev.parent = &pdev->dev;
168	input_dev->open = pcap_ts_open;
169	input_dev->close = pcap_ts_close;
170
171	input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
172	input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
173	input_set_abs_params(input_dev, ABS_X, X_AXIS_MIN, X_AXIS_MAX, 0, 0);
174	input_set_abs_params(input_dev, ABS_Y, Y_AXIS_MIN, Y_AXIS_MAX, 0, 0);
175	input_set_abs_params(input_dev, ABS_PRESSURE, PRESSURE_MIN,
176			     PRESSURE_MAX, 0, 0);
177
178	err = input_register_device(pcap_ts->input);
179	if (err)
180		goto fail_allocate;
181
182	err = request_irq(pcap_to_irq(pcap_ts->pcap, PCAP_IRQ_TS),
183			pcap_ts_event_touch, 0, "Touch Screen", pcap_ts);
184	if (err)
185		goto fail_register;
186
187	return 0;
188
189fail_register:
190	input_unregister_device(input_dev);
191	goto fail;
192fail_allocate:
193	input_free_device(input_dev);
194fail:
195	kfree(pcap_ts);
196
197	return err;
198}
199
200static int pcap_ts_remove(struct platform_device *pdev)
201{
202	struct pcap_ts *pcap_ts = platform_get_drvdata(pdev);
203
204	free_irq(pcap_to_irq(pcap_ts->pcap, PCAP_IRQ_TS), pcap_ts);
205	cancel_delayed_work_sync(&pcap_ts->work);
206
207	input_unregister_device(pcap_ts->input);
208
209	kfree(pcap_ts);
210
211	return 0;
212}
213
214#ifdef CONFIG_PM
215static int pcap_ts_suspend(struct device *dev)
216{
217	struct pcap_ts *pcap_ts = dev_get_drvdata(dev);
218
219	pcap_set_ts_bits(pcap_ts->pcap, PCAP_ADC_TS_REF_LOWPWR);
220	return 0;
221}
222
223static int pcap_ts_resume(struct device *dev)
224{
225	struct pcap_ts *pcap_ts = dev_get_drvdata(dev);
226
227	pcap_set_ts_bits(pcap_ts->pcap,
228				pcap_ts->read_state << PCAP_ADC_TS_M_SHIFT);
229	return 0;
230}
231
232static const struct dev_pm_ops pcap_ts_pm_ops = {
233	.suspend	= pcap_ts_suspend,
234	.resume		= pcap_ts_resume,
235};
236#define PCAP_TS_PM_OPS (&pcap_ts_pm_ops)
237#else
238#define PCAP_TS_PM_OPS NULL
239#endif
240
241static struct platform_driver pcap_ts_driver = {
242	.probe		= pcap_ts_probe,
243	.remove		= pcap_ts_remove,
244	.driver		= {
245		.name	= "pcap-ts",
246		.pm	= PCAP_TS_PM_OPS,
247	},
248};
249module_platform_driver(pcap_ts_driver);
250
251MODULE_DESCRIPTION("Motorola PCAP2 touchscreen driver");
252MODULE_AUTHOR("Daniel Ribeiro / Harald Welte");
253MODULE_LICENSE("GPL");
254MODULE_ALIAS("platform:pcap_ts");