/*
* 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 program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*/
/*
* 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:
/* fall through */
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,
const struct i2c_device_id *id)
{
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);
input_set_drvdata(input_dev, data);
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;
i2c_set_clientdata(client, data);
return 0;
}
static const struct i2c_device_id max11801_ts_id[] = {
{"max11801", 0},
{ }
};
MODULE_DEVICE_TABLE(i2c, max11801_ts_id);
static struct i2c_driver max11801_ts_driver = {
.driver = {
.name = "max11801_ts",
.owner = THIS_MODULE,
},
.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");
