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