1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * Driver for EETI eGalax Multiple Touch Controller
  4 *
  5 * Copyright (C) 2011 Freescale Semiconductor, Inc.
  6 *
  7 * based on max11801_ts.c
  8 */
  9
 10/* EETI eGalax serial touch screen controller is a I2C based multiple
 11 * touch screen controller, it supports 5 point multiple touch. */
 12
 13/* TODO:
 14  - auto idle mode support
 15*/
 16
 17#include <linux/module.h>
 18#include <linux/i2c.h>
 19#include <linux/interrupt.h>
 20#include <linux/input.h>
 21#include <linux/irq.h>
 22#include <linux/gpio.h>
 23#include <linux/delay.h>
 24#include <linux/slab.h>
 25#include <linux/bitops.h>
 26#include <linux/input/mt.h>
 27#include <linux/of_gpio.h>
 28
 29/*
 30 * Mouse Mode: some panel may configure the controller to mouse mode,
 31 * which can only report one point at a given time.
 32 * This driver will ignore events in this mode.
 33 */
 34#define REPORT_MODE_MOUSE		0x1
 35/*
 36 * Vendor Mode: this mode is used to transfer some vendor specific
 37 * messages.
 38 * This driver will ignore events in this mode.
 39 */
 40#define REPORT_MODE_VENDOR		0x3
 41/* Multiple Touch Mode */
 42#define REPORT_MODE_MTTOUCH		0x4
 43
 44#define MAX_SUPPORT_POINTS		5
 45
 46#define EVENT_VALID_OFFSET	7
 47#define EVENT_VALID_MASK	(0x1 << EVENT_VALID_OFFSET)
 48#define EVENT_ID_OFFSET		2
 49#define EVENT_ID_MASK		(0xf << EVENT_ID_OFFSET)
 50#define EVENT_IN_RANGE		(0x1 << 1)
 51#define EVENT_DOWN_UP		(0X1 << 0)
 52
 53#define MAX_I2C_DATA_LEN	10
 54
 55#define EGALAX_MAX_X	32760
 56#define EGALAX_MAX_Y	32760
 57#define EGALAX_MAX_TRIES 100
 58
 59struct egalax_ts {
 60	struct i2c_client		*client;
 61	struct input_dev		*input_dev;
 62};
 63
 64static irqreturn_t egalax_ts_interrupt(int irq, void *dev_id)
 65{
 66	struct egalax_ts *ts = dev_id;
 67	struct input_dev *input_dev = ts->input_dev;
 68	struct i2c_client *client = ts->client;
 69	u8 buf[MAX_I2C_DATA_LEN];
 70	int id, ret, x, y, z;
 71	int tries = 0;
 72	bool down, valid;
 73	u8 state;
 74
 75	do {
 76		ret = i2c_master_recv(client, buf, MAX_I2C_DATA_LEN);
 77	} while (ret == -EAGAIN && tries++ < EGALAX_MAX_TRIES);
 78
 79	if (ret < 0)
 80		return IRQ_HANDLED;
 81
 82	if (buf[0] != REPORT_MODE_MTTOUCH) {
 83		/* ignore mouse events and vendor events */
 84		return IRQ_HANDLED;
 85	}
 86
 87	state = buf[1];
 88	x = (buf[3] << 8) | buf[2];
 89	y = (buf[5] << 8) | buf[4];
 90	z = (buf[7] << 8) | buf[6];
 91
 92	valid = state & EVENT_VALID_MASK;
 93	id = (state & EVENT_ID_MASK) >> EVENT_ID_OFFSET;
 94	down = state & EVENT_DOWN_UP;
 95
 96	if (!valid || id > MAX_SUPPORT_POINTS) {
 97		dev_dbg(&client->dev, "point invalid\n");
 98		return IRQ_HANDLED;
 99	}
100
101	input_mt_slot(input_dev, id);
102	input_mt_report_slot_state(input_dev, MT_TOOL_FINGER, down);
103
104	dev_dbg(&client->dev, "%s id:%d x:%d y:%d z:%d",
105		down ? "down" : "up", id, x, y, z);
106
107	if (down) {
108		input_report_abs(input_dev, ABS_MT_POSITION_X, x);
109		input_report_abs(input_dev, ABS_MT_POSITION_Y, y);
110		input_report_abs(input_dev, ABS_MT_PRESSURE, z);
111	}
112
113	input_mt_report_pointer_emulation(input_dev, true);
114	input_sync(input_dev);
115
116	return IRQ_HANDLED;
117}
118
119/* wake up controller by an falling edge of interrupt gpio.  */
120static int egalax_wake_up_device(struct i2c_client *client)
121{
122	struct device_node *np = client->dev.of_node;
123	int gpio;
124	int ret;
125
126	if (!np)
127		return -ENODEV;
128
129	gpio = of_get_named_gpio(np, "wakeup-gpios", 0);
130	if (!gpio_is_valid(gpio))
131		return -ENODEV;
132
133	ret = gpio_request(gpio, "egalax_irq");
134	if (ret < 0) {
135		dev_err(&client->dev,
136			"request gpio failed, cannot wake up controller: %d\n",
137			ret);
138		return ret;
139	}
140
141	/* wake up controller via an falling edge on IRQ gpio. */
142	gpio_direction_output(gpio, 0);
143	gpio_set_value(gpio, 1);
144
145	/* controller should be waken up, return irq.  */
146	gpio_direction_input(gpio);
147	gpio_free(gpio);
148
149	return 0;
150}
151
152static int egalax_firmware_version(struct i2c_client *client)
153{
154	static const u8 cmd[MAX_I2C_DATA_LEN] = { 0x03, 0x03, 0xa, 0x01, 0x41 };
155	int ret;
156
157	ret = i2c_master_send(client, cmd, MAX_I2C_DATA_LEN);
158	if (ret < 0)
159		return ret;
160
161	return 0;
162}
163
164static int egalax_ts_probe(struct i2c_client *client,
165			   const struct i2c_device_id *id)
166{
167	struct egalax_ts *ts;
168	struct input_dev *input_dev;
169	int error;
170
171	ts = devm_kzalloc(&client->dev, sizeof(struct egalax_ts), GFP_KERNEL);
172	if (!ts) {
173		dev_err(&client->dev, "Failed to allocate memory\n");
174		return -ENOMEM;
175	}
176
177	input_dev = devm_input_allocate_device(&client->dev);
178	if (!input_dev) {
179		dev_err(&client->dev, "Failed to allocate memory\n");
180		return -ENOMEM;
181	}
182
183	ts->client = client;
184	ts->input_dev = input_dev;
185
186	/* controller may be in sleep, wake it up. */
187	error = egalax_wake_up_device(client);
188	if (error) {
189		dev_err(&client->dev, "Failed to wake up the controller\n");
190		return error;
191	}
192
193	error = egalax_firmware_version(client);
194	if (error < 0) {
195		dev_err(&client->dev, "Failed to read firmware version\n");
196		return error;
197	}
198
199	input_dev->name = "EETI eGalax Touch Screen";
200	input_dev->id.bustype = BUS_I2C;
201
202	__set_bit(EV_ABS, input_dev->evbit);
203	__set_bit(EV_KEY, input_dev->evbit);
204	__set_bit(BTN_TOUCH, input_dev->keybit);
205
206	input_set_abs_params(input_dev, ABS_X, 0, EGALAX_MAX_X, 0, 0);
207	input_set_abs_params(input_dev, ABS_Y, 0, EGALAX_MAX_Y, 0, 0);
208	input_set_abs_params(input_dev,
209			     ABS_MT_POSITION_X, 0, EGALAX_MAX_X, 0, 0);
210	input_set_abs_params(input_dev,
211			     ABS_MT_POSITION_Y, 0, EGALAX_MAX_Y, 0, 0);
212	input_mt_init_slots(input_dev, MAX_SUPPORT_POINTS, 0);
213
214	error = devm_request_threaded_irq(&client->dev, client->irq, NULL,
215					  egalax_ts_interrupt,
216					  IRQF_TRIGGER_LOW | IRQF_ONESHOT,
217					  "egalax_ts", ts);
218	if (error < 0) {
219		dev_err(&client->dev, "Failed to register interrupt\n");
220		return error;
221	}
222
223	error = input_register_device(ts->input_dev);
224	if (error)
225		return error;
226
227	return 0;
228}
229
230static const struct i2c_device_id egalax_ts_id[] = {
231	{ "egalax_ts", 0 },
232	{ }
233};
234MODULE_DEVICE_TABLE(i2c, egalax_ts_id);
235
236static int __maybe_unused egalax_ts_suspend(struct device *dev)
237{
238	static const u8 suspend_cmd[MAX_I2C_DATA_LEN] = {
239		0x3, 0x6, 0xa, 0x3, 0x36, 0x3f, 0x2, 0, 0, 0
240	};
241	struct i2c_client *client = to_i2c_client(dev);
242	int ret;
243
244	if (device_may_wakeup(dev))
245		return enable_irq_wake(client->irq);
246
247	ret = i2c_master_send(client, suspend_cmd, MAX_I2C_DATA_LEN);
248	return ret > 0 ? 0 : ret;
249}
250
251static int __maybe_unused egalax_ts_resume(struct device *dev)
252{
253	struct i2c_client *client = to_i2c_client(dev);
254
255	if (device_may_wakeup(dev))
256		return disable_irq_wake(client->irq);
257
258	return egalax_wake_up_device(client);
259}
260
261static SIMPLE_DEV_PM_OPS(egalax_ts_pm_ops, egalax_ts_suspend, egalax_ts_resume);
262
263static const struct of_device_id egalax_ts_dt_ids[] = {
264	{ .compatible = "eeti,egalax_ts" },
265	{ /* sentinel */ }
266};
267MODULE_DEVICE_TABLE(of, egalax_ts_dt_ids);
268
269static struct i2c_driver egalax_ts_driver = {
270	.driver = {
271		.name	= "egalax_ts",
272		.pm	= &egalax_ts_pm_ops,
273		.of_match_table	= egalax_ts_dt_ids,
274	},
275	.id_table	= egalax_ts_id,
276	.probe		= egalax_ts_probe,
277};
278
279module_i2c_driver(egalax_ts_driver);
280
281MODULE_AUTHOR("Freescale Semiconductor, Inc.");
282MODULE_DESCRIPTION("Touchscreen driver for EETI eGalax touch controller");
283MODULE_LICENSE("GPL");