// SPDX-License-Identifier: GPL-2.0-or-later/* * Driver for MAXI MAX11801 - A Resistive touch screen controller with * i2c interface * * Copyright (C) 2011 Freescale Semiconductor, Inc. * Author: Zhang Jiejing <jiejing.zhang@freescale.com> * * Based on mcs5000_ts.c */ /* * This driver aims to support the series of MAXI touch chips max11801 * through max11803. The main difference between these 4 chips can be * found in the table below: * ----------------------------------------------------- * | CHIP     |  AUTO MODE SUPPORT(FIFO) | INTERFACE    | * |----------------------------------------------------| * | max11800 |  YES                     |   SPI        | * | max11801 |  YES                     |   I2C        | * | max11802 |  NO                      |   SPI        | * | max11803 |  NO                      |   I2C        | * ------------------------------------------------------ * * Currently, this driver only supports max11801. * * Data Sheet: * http://www.maxim-ic.com/datasheet/index.mvp/id/5943 */ #include <linux/module.h>#include <linux/i2c.h>#include <linux/interrupt.h>#include <linux/input.h>#include <linux/slab.h>#include <linux/bitops.h> /* Register Address define */#define GENERNAL_STATUS_REG		0x00#define GENERNAL_CONF_REG		0x01#define MESURE_RES_CONF_REG		0x02#define MESURE_AVER_CONF_REG		0x03#define ADC_SAMPLE_TIME_CONF_REG	0x04#define PANEL_SETUPTIME_CONF_REG	0x05#define DELAY_CONVERSION_CONF_REG	0x06#define TOUCH_DETECT_PULLUP_CONF_REG	0x07#define AUTO_MODE_TIME_CONF_REG		0x08 /* only for max11800/max11801 */#define APERTURE_CONF_REG		0x09 /* only for max11800/max11801 */#define AUX_MESURE_CONF_REG		0x0a#define OP_MODE_CONF_REG		0x0b /* FIFO is found only in max11800 and max11801 */#define FIFO_RD_CMD			(0x50 << 1)#define MAX11801_FIFO_INT		(1 << 2)#define MAX11801_FIFO_OVERFLOW		(1 << 3) #define XY_BUFSIZE			4#define XY_BUF_OFFSET			4 #define MAX11801_MAX_X			0xfff#define MAX11801_MAX_Y			0xfff #define MEASURE_TAG_OFFSET		2#define MEASURE_TAG_MASK		(3 << MEASURE_TAG_OFFSET)#define EVENT_TAG_OFFSET		0#define EVENT_TAG_MASK			(3 << EVENT_TAG_OFFSET)#define MEASURE_X_TAG			(0 << MEASURE_TAG_OFFSET)#define MEASURE_Y_TAG			(1 << MEASURE_TAG_OFFSET) /* These are the state of touch event state machine */enum {	EVENT_INIT,	EVENT_MIDDLE,	EVENT_RELEASE,	EVENT_FIFO_END}; struct max11801_data {	struct i2c_client		*client;	struct input_dev		*input_dev;}; static u8 read_register(struct i2c_client *client, int addr){	/* XXX: The chip ignores LSB of register address */	return i2c_smbus_read_byte_data(client, addr << 1);} static int max11801_write_reg(struct i2c_client *client, int addr, int data){	/* XXX: The chip ignores LSB of register address */	return i2c_smbus_write_byte_data(client, addr << 1, data);} static irqreturn_t max11801_ts_interrupt(int irq, void *dev_id){	struct max11801_data *data = dev_id;	struct i2c_client *client = data->client;	int status, i, ret;	u8 buf[XY_BUFSIZE];	int x = -1;	int y = -1; 	status = read_register(data->client, GENERNAL_STATUS_REG); 	if (status & (MAX11801_FIFO_INT | MAX11801_FIFO_OVERFLOW)) {		status = read_register(data->client, GENERNAL_STATUS_REG); 		ret = i2c_smbus_read_i2c_block_data(client, FIFO_RD_CMD,						    XY_BUFSIZE, buf); 		/*		 * We should get 4 bytes buffer that contains X,Y		 * and event tag		 */		if (ret < XY_BUFSIZE)			goto out; 		for (i = 0; i < XY_BUFSIZE; i += XY_BUFSIZE / 2) {			if ((buf[i + 1] & MEASURE_TAG_MASK) == MEASURE_X_TAG)				x = (buf[i] << XY_BUF_OFFSET) +				    (buf[i + 1] >> XY_BUF_OFFSET);			else if ((buf[i + 1] & MEASURE_TAG_MASK) == MEASURE_Y_TAG)				y = (buf[i] << XY_BUF_OFFSET) +				    (buf[i + 1] >> XY_BUF_OFFSET);		} 		if ((buf[1] & EVENT_TAG_MASK) != (buf[3] & EVENT_TAG_MASK))			goto out; 		switch (buf[1] & EVENT_TAG_MASK) {		case EVENT_INIT:		case EVENT_MIDDLE:			input_report_abs(data->input_dev, ABS_X, x);			input_report_abs(data->input_dev, ABS_Y, y);			input_event(data->input_dev, EV_KEY, BTN_TOUCH, 1);			input_sync(data->input_dev);			break; 		case EVENT_RELEASE:			input_event(data->input_dev, EV_KEY, BTN_TOUCH, 0);			input_sync(data->input_dev);			break; 		case EVENT_FIFO_END:			break;		}	}out:	return IRQ_HANDLED;} static void max11801_ts_phy_init(struct max11801_data *data){	struct i2c_client *client = data->client; 	/* Average X,Y, take 16 samples, average eight media sample */	max11801_write_reg(client, MESURE_AVER_CONF_REG, 0xff);	/* X,Y panel setup time set to 20us */	max11801_write_reg(client, PANEL_SETUPTIME_CONF_REG, 0x11);	/* Rough pullup time (2uS), Fine pullup time (10us)  */	max11801_write_reg(client, TOUCH_DETECT_PULLUP_CONF_REG, 0x10);	/* Auto mode init period = 5ms , scan period = 5ms*/	max11801_write_reg(client, AUTO_MODE_TIME_CONF_REG, 0xaa);	/* Aperture X,Y set to +- 4LSB */	max11801_write_reg(client, APERTURE_CONF_REG, 0x33);	/* Enable Power, enable Automode, enable Aperture, enable Average X,Y */	max11801_write_reg(client, OP_MODE_CONF_REG, 0x36);} static int max11801_ts_probe(struct i2c_client *client){	struct max11801_data *data;	struct input_dev *input_dev;	int error; 	data = devm_kzalloc(&client->dev, sizeof(*data), GFP_KERNEL);	input_dev = devm_input_allocate_device(&client->dev);	if (!data || !input_dev) {		dev_err(&client->dev, "Failed to allocate memory\n");		return -ENOMEM;	} 	data->client = client;	data->input_dev = input_dev; 	input_dev->name = "max11801_ts";	input_dev->id.bustype = BUS_I2C;	input_dev->dev.parent = &client->dev; 	__set_bit(EV_ABS, input_dev->evbit);	__set_bit(EV_KEY, input_dev->evbit);	__set_bit(BTN_TOUCH, input_dev->keybit);	input_set_abs_params(input_dev, ABS_X, 0, MAX11801_MAX_X, 0, 0);	input_set_abs_params(input_dev, ABS_Y, 0, MAX11801_MAX_Y, 0, 0); 	max11801_ts_phy_init(data); 	error = devm_request_threaded_irq(&client->dev, client->irq, NULL,					  max11801_ts_interrupt,					  IRQF_TRIGGER_LOW | IRQF_ONESHOT,					  "max11801_ts", data);	if (error) {		dev_err(&client->dev, "Failed to register interrupt\n");		return error;	} 	error = input_register_device(data->input_dev);	if (error)		return error; 	return 0;} static const struct i2c_device_id max11801_ts_id[] = {	{ .name = "max11801" },	{ }};MODULE_DEVICE_TABLE(i2c, max11801_ts_id); static const struct of_device_id max11801_ts_dt_ids[] = {	{ .compatible = "maxim,max11801" },	{ /* sentinel */ }};MODULE_DEVICE_TABLE(of, max11801_ts_dt_ids); static struct i2c_driver max11801_ts_driver = {	.driver = {		.name	= "max11801_ts",		.of_match_table = max11801_ts_dt_ids,	},	.id_table	= max11801_ts_id,	.probe		= max11801_ts_probe,}; module_i2c_driver(max11801_ts_driver); MODULE_AUTHOR("Zhang Jiejing <jiejing.zhang@freescale.com>");MODULE_DESCRIPTION("Touchscreen driver for MAXI MAX11801 controller");MODULE_LICENSE("GPL");