/* * 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); 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[] = { {"max11801", 0}, { } }; 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");