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 void 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
212#ifdef CONFIG_PM
213static int pcap_ts_suspend(struct device *dev)
214{
215	struct pcap_ts *pcap_ts = dev_get_drvdata(dev);
216
217	pcap_set_ts_bits(pcap_ts->pcap, PCAP_ADC_TS_REF_LOWPWR);
218	return 0;
219}
220
221static int pcap_ts_resume(struct device *dev)
222{
223	struct pcap_ts *pcap_ts = dev_get_drvdata(dev);
224
225	pcap_set_ts_bits(pcap_ts->pcap,
226				pcap_ts->read_state << PCAP_ADC_TS_M_SHIFT);
227	return 0;
228}
229
230static const struct dev_pm_ops pcap_ts_pm_ops = {
231	.suspend	= pcap_ts_suspend,
232	.resume		= pcap_ts_resume,
233};
234#define PCAP_TS_PM_OPS (&pcap_ts_pm_ops)
235#else
236#define PCAP_TS_PM_OPS NULL
237#endif
238
239static struct platform_driver pcap_ts_driver = {
240	.probe		= pcap_ts_probe,
241	.remove_new	= pcap_ts_remove,
242	.driver		= {
243		.name	= "pcap-ts",
244		.pm	= PCAP_TS_PM_OPS,
245	},
246};
247module_platform_driver(pcap_ts_driver);
248
249MODULE_DESCRIPTION("Motorola PCAP2 touchscreen driver");
250MODULE_AUTHOR("Daniel Ribeiro / Harald Welte");
251MODULE_LICENSE("GPL");
252MODULE_ALIAS("platform:pcap_ts");
253