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  1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 * Copyright (C) 2016, Jelle van der Waa <jelle@vdwaa.nl>
  4 */
  5
  6#include <linux/delay.h>
  7#include <linux/i2c.h>
  8#include <linux/input.h>
  9#include <linux/input/mt.h>
 10#include <linux/input/touchscreen.h>
 11#include <linux/interrupt.h>
 12#include <linux/module.h>
 13#include <linux/regulator/consumer.h>
 14#include <asm/unaligned.h>
 15
 16#define ZET6223_MAX_FINGERS		16
 17#define ZET6223_MAX_PKT_SIZE		(3 + 4 * ZET6223_MAX_FINGERS)
 18
 19#define ZET6223_CMD_INFO		0xB2
 20#define ZET6223_CMD_INFO_LENGTH		17
 21#define ZET6223_VALID_PACKET		0x3c
 22
 23#define ZET6223_POWER_ON_DELAY_MSEC	30
 24
 25struct zet6223_ts {
 26	struct i2c_client *client;
 27	struct input_dev *input;
 28	struct regulator *vcc;
 29	struct regulator *vio;
 30	struct touchscreen_properties prop;
 31	struct regulator_bulk_data supplies[2];
 32	u16 max_x;
 33	u16 max_y;
 34	u8 fingernum;
 35};
 36
 37static int zet6223_start(struct input_dev *dev)
 38{
 39	struct zet6223_ts *ts = input_get_drvdata(dev);
 40
 41	enable_irq(ts->client->irq);
 42
 43	return 0;
 44}
 45
 46static void zet6223_stop(struct input_dev *dev)
 47{
 48	struct zet6223_ts *ts = input_get_drvdata(dev);
 49
 50	disable_irq(ts->client->irq);
 51}
 52
 53static irqreturn_t zet6223_irq(int irq, void *dev_id)
 54{
 55	struct zet6223_ts *ts = dev_id;
 56	u16 finger_bits;
 57
 58	/*
 59	 * First 3 bytes are an identifier, two bytes of finger data.
 60	 * X, Y data per finger is 4 bytes.
 61	 */
 62	u8 bufsize = 3 + 4 * ts->fingernum;
 63	u8 buf[ZET6223_MAX_PKT_SIZE];
 64	int i;
 65	int ret;
 66	int error;
 67
 68	ret = i2c_master_recv(ts->client, buf, bufsize);
 69	if (ret != bufsize) {
 70		error = ret < 0 ? ret : -EIO;
 71		dev_err_ratelimited(&ts->client->dev,
 72				    "Error reading input data: %d\n", error);
 73		return IRQ_HANDLED;
 74	}
 75
 76	if (buf[0] != ZET6223_VALID_PACKET)
 77		return IRQ_HANDLED;
 78
 79	finger_bits = get_unaligned_be16(buf + 1);
 80	for (i = 0; i < ts->fingernum; i++) {
 81		if (!(finger_bits & BIT(15 - i)))
 82			continue;
 83
 84		input_mt_slot(ts->input, i);
 85		input_mt_report_slot_state(ts->input, MT_TOOL_FINGER, true);
 86		input_event(ts->input, EV_ABS, ABS_MT_POSITION_X,
 87				((buf[i + 3] >> 4) << 8) + buf[i + 4]);
 88		input_event(ts->input, EV_ABS, ABS_MT_POSITION_Y,
 89				((buf[i + 3] & 0xF) << 8) + buf[i + 5]);
 90	}
 91
 92	input_mt_sync_frame(ts->input);
 93	input_sync(ts->input);
 94
 95	return IRQ_HANDLED;
 96}
 97
 98static void zet6223_power_off(void *_ts)
 99{
100	struct zet6223_ts *ts = _ts;
101
102	regulator_bulk_disable(ARRAY_SIZE(ts->supplies), ts->supplies);
103}
104
105static int zet6223_power_on(struct zet6223_ts *ts)
106{
107	struct device *dev = &ts->client->dev;
108	int error;
109
110	ts->supplies[0].supply = "vio";
111	ts->supplies[1].supply = "vcc";
112
113	error = devm_regulator_bulk_get(dev, ARRAY_SIZE(ts->supplies),
114					ts->supplies);
115	if (error)
116		return error;
117
118	error = regulator_bulk_enable(ARRAY_SIZE(ts->supplies), ts->supplies);
119	if (error)
120		return error;
121
122	msleep(ZET6223_POWER_ON_DELAY_MSEC);
123
124	error = devm_add_action_or_reset(dev, zet6223_power_off, ts);
125	if (error) {
126		dev_err(dev, "failed to install poweroff action: %d\n", error);
127		return error;
128	}
129
130	return 0;
131}
132
133static int zet6223_query_device(struct zet6223_ts *ts)
134{
135	u8 buf[ZET6223_CMD_INFO_LENGTH];
136	u8 cmd = ZET6223_CMD_INFO;
137	int ret;
138	int error;
139
140	ret = i2c_master_send(ts->client, &cmd, sizeof(cmd));
141	if (ret != sizeof(cmd)) {
142		error = ret < 0 ? ret : -EIO;
143		dev_err(&ts->client->dev,
144			"touchpanel info cmd failed: %d\n", error);
145		return error;
146	}
147
148	ret = i2c_master_recv(ts->client, buf, sizeof(buf));
149	if (ret != sizeof(buf)) {
150		error = ret < 0 ? ret : -EIO;
151		dev_err(&ts->client->dev,
152			"failed to retrieve touchpanel info: %d\n", error);
153		return error;
154	}
155
156	ts->fingernum = buf[15] & 0x7F;
157	if (ts->fingernum > ZET6223_MAX_FINGERS) {
158		dev_warn(&ts->client->dev,
159			 "touchpanel reports %d fingers, limiting to %d\n",
160			 ts->fingernum, ZET6223_MAX_FINGERS);
161		ts->fingernum = ZET6223_MAX_FINGERS;
162	}
163
164	ts->max_x = get_unaligned_le16(&buf[8]);
165	ts->max_y = get_unaligned_le16(&buf[10]);
166
167	return 0;
168}
169
170static int zet6223_probe(struct i2c_client *client)
171{
172	struct device *dev = &client->dev;
173	struct zet6223_ts *ts;
174	struct input_dev *input;
175	int error;
176
177	if (!client->irq) {
178		dev_err(dev, "no irq specified\n");
179		return -EINVAL;
180	}
181
182	ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL);
183	if (!ts)
184		return -ENOMEM;
185
186	ts->client = client;
187
188	error = zet6223_power_on(ts);
189	if (error)
190		return error;
191
192	error = zet6223_query_device(ts);
193	if (error)
194		return error;
195
196	ts->input = input = devm_input_allocate_device(dev);
197	if (!input)
198		return -ENOMEM;
199
200	input_set_drvdata(input, ts);
201
202	input->name = client->name;
203	input->id.bustype = BUS_I2C;
204	input->open = zet6223_start;
205	input->close = zet6223_stop;
206
207	input_set_abs_params(input, ABS_MT_POSITION_X, 0, ts->max_x, 0, 0);
208	input_set_abs_params(input, ABS_MT_POSITION_Y, 0, ts->max_y, 0, 0);
209
210	touchscreen_parse_properties(input, true, &ts->prop);
211
212	error = input_mt_init_slots(input, ts->fingernum,
213				    INPUT_MT_DIRECT | INPUT_MT_DROP_UNUSED);
214	if (error)
215		return error;
216
217	error = devm_request_threaded_irq(dev, client->irq, NULL, zet6223_irq,
218					  IRQF_ONESHOT, client->name, ts);
219	if (error) {
220		dev_err(dev, "failed to request irq %d: %d\n",
221			client->irq, error);
222		return error;
223	}
224
225	zet6223_stop(input);
226
227	error = input_register_device(input);
228	if (error)
229		return error;
230
231	return 0;
232}
233
234static const struct of_device_id zet6223_of_match[] = {
235	{ .compatible = "zeitec,zet6223" },
236	{ }
237};
238MODULE_DEVICE_TABLE(of, zet6223_of_match);
239
240static const struct i2c_device_id zet6223_id[] = {
241	{ "zet6223", 0},
242	{ }
243};
244MODULE_DEVICE_TABLE(i2c, zet6223_id);
245
246static struct i2c_driver zet6223_driver = {
247	.driver = {
248		.name = "zet6223",
249		.of_match_table = zet6223_of_match,
250	},
251	.probe_new = zet6223_probe,
252	.id_table = zet6223_id
253};
254module_i2c_driver(zet6223_driver);
255
256MODULE_AUTHOR("Jelle van der Waa <jelle@vdwaa.nl>");
257MODULE_DESCRIPTION("ZEITEC zet622x I2C touchscreen driver");
258MODULE_LICENSE("GPL");