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