2 * Driver for MAXI MAX11801 - A Resistive touch screen controller with
5 * Copyright (C) 2011 Freescale Semiconductor, Inc.
6 * Author: Zhang Jiejing <jiejing.zhang@freescale.com>
8 * Based on mcs5000_ts.c
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
17 * This driver aims to support the series of MAXI touch chips max11801
18 * through max11803. The main difference between these 4 chips can be
19 * found in the table below:
20 * -----------------------------------------------------
21 * | CHIP | AUTO MODE SUPPORT(FIFO) | INTERFACE |
22 * |----------------------------------------------------|
23 * | max11800 | YES | SPI |
24 * | max11801 | YES | I2C |
25 * | max11802 | NO | SPI |
26 * | max11803 | NO | I2C |
27 * ------------------------------------------------------
29 * Currently, this driver only supports max11801.
32 * http://www.maxim-ic.com/datasheet/index.mvp/id/5943
35 #include <linux/module.h>
36 #include <linux/i2c.h>
37 #include <linux/interrupt.h>
38 #include <linux/input.h>
39 #include <linux/slab.h>
40 #include <linux/bitops.h>
42 /* Register Address define */
43 #define GENERNAL_STATUS_REG 0x00
44 #define GENERNAL_CONF_REG 0x01
45 #define MESURE_RES_CONF_REG 0x02
46 #define MESURE_AVER_CONF_REG 0x03
47 #define ADC_SAMPLE_TIME_CONF_REG 0x04
48 #define PANEL_SETUPTIME_CONF_REG 0x05
49 #define DELAY_CONVERSION_CONF_REG 0x06
50 #define TOUCH_DETECT_PULLUP_CONF_REG 0x07
51 #define AUTO_MODE_TIME_CONF_REG 0x08 /* only for max11800/max11801 */
52 #define APERTURE_CONF_REG 0x09 /* only for max11800/max11801 */
53 #define AUX_MESURE_CONF_REG 0x0a
54 #define OP_MODE_CONF_REG 0x0b
56 /* FIFO is found only in max11800 and max11801 */
57 #define FIFO_RD_CMD (0x50 << 1)
58 #define MAX11801_FIFO_INT (1 << 2)
59 #define MAX11801_FIFO_OVERFLOW (1 << 3)
62 #define XY_BUF_OFFSET 4
64 #define MAX11801_MAX_X 0xfff
65 #define MAX11801_MAX_Y 0xfff
67 #define MEASURE_TAG_OFFSET 2
68 #define MEASURE_TAG_MASK (3 << MEASURE_TAG_OFFSET)
69 #define EVENT_TAG_OFFSET 0
70 #define EVENT_TAG_MASK (3 << EVENT_TAG_OFFSET)
71 #define MEASURE_X_TAG (0 << MEASURE_TAG_OFFSET)
72 #define MEASURE_Y_TAG (1 << MEASURE_TAG_OFFSET)
74 /* These are the state of touch event state machine */
82 struct max11801_data {
83 struct i2c_client *client;
84 struct input_dev *input_dev;
87 static u8 read_register(struct i2c_client *client, int addr)
89 /* XXX: The chip ignores LSB of register address */
90 return i2c_smbus_read_byte_data(client, addr << 1);
93 static int max11801_write_reg(struct i2c_client *client, int addr, int data)
95 /* XXX: The chip ignores LSB of register address */
96 return i2c_smbus_write_byte_data(client, addr << 1, data);
99 static irqreturn_t max11801_ts_interrupt(int irq, void *dev_id)
101 struct max11801_data *data = dev_id;
102 struct i2c_client *client = data->client;
108 status = read_register(data->client, GENERNAL_STATUS_REG);
110 if (status & (MAX11801_FIFO_INT | MAX11801_FIFO_OVERFLOW)) {
111 status = read_register(data->client, GENERNAL_STATUS_REG);
113 ret = i2c_smbus_read_i2c_block_data(client, FIFO_RD_CMD,
117 * We should get 4 bytes buffer that contains X,Y
120 if (ret < XY_BUFSIZE)
123 for (i = 0; i < XY_BUFSIZE; i += XY_BUFSIZE / 2) {
124 if ((buf[i + 1] & MEASURE_TAG_MASK) == MEASURE_X_TAG)
125 x = (buf[i] << XY_BUF_OFFSET) +
126 (buf[i + 1] >> XY_BUF_OFFSET);
127 else if ((buf[i + 1] & MEASURE_TAG_MASK) == MEASURE_Y_TAG)
128 y = (buf[i] << XY_BUF_OFFSET) +
129 (buf[i + 1] >> XY_BUF_OFFSET);
132 if ((buf[1] & EVENT_TAG_MASK) != (buf[3] & EVENT_TAG_MASK))
135 switch (buf[1] & EVENT_TAG_MASK) {
139 input_report_abs(data->input_dev, ABS_X, x);
140 input_report_abs(data->input_dev, ABS_Y, y);
141 input_event(data->input_dev, EV_KEY, BTN_TOUCH, 1);
142 input_sync(data->input_dev);
146 input_event(data->input_dev, EV_KEY, BTN_TOUCH, 0);
147 input_sync(data->input_dev);
158 static void max11801_ts_phy_init(struct max11801_data *data)
160 struct i2c_client *client = data->client;
162 /* Average X,Y, take 16 samples, average eight media sample */
163 max11801_write_reg(client, MESURE_AVER_CONF_REG, 0xff);
164 /* X,Y panel setup time set to 20us */
165 max11801_write_reg(client, PANEL_SETUPTIME_CONF_REG, 0x11);
166 /* Rough pullup time (2uS), Fine pullup time (10us) */
167 max11801_write_reg(client, TOUCH_DETECT_PULLUP_CONF_REG, 0x10);
168 /* Auto mode init period = 5ms , scan period = 5ms*/
169 max11801_write_reg(client, AUTO_MODE_TIME_CONF_REG, 0xaa);
170 /* Aperture X,Y set to +- 4LSB */
171 max11801_write_reg(client, APERTURE_CONF_REG, 0x33);
172 /* Enable Power, enable Automode, enable Aperture, enable Average X,Y */
173 max11801_write_reg(client, OP_MODE_CONF_REG, 0x36);
176 static int max11801_ts_probe(struct i2c_client *client,
177 const struct i2c_device_id *id)
179 struct max11801_data *data;
180 struct input_dev *input_dev;
183 data = devm_kzalloc(&client->dev, sizeof(*data), GFP_KERNEL);
184 input_dev = devm_input_allocate_device(&client->dev);
185 if (!data || !input_dev) {
186 dev_err(&client->dev, "Failed to allocate memory\n");
190 data->client = client;
191 data->input_dev = input_dev;
193 input_dev->name = "max11801_ts";
194 input_dev->id.bustype = BUS_I2C;
195 input_dev->dev.parent = &client->dev;
197 __set_bit(EV_ABS, input_dev->evbit);
198 __set_bit(EV_KEY, input_dev->evbit);
199 __set_bit(BTN_TOUCH, input_dev->keybit);
200 input_set_abs_params(input_dev, ABS_X, 0, MAX11801_MAX_X, 0, 0);
201 input_set_abs_params(input_dev, ABS_Y, 0, MAX11801_MAX_Y, 0, 0);
203 max11801_ts_phy_init(data);
205 error = devm_request_threaded_irq(&client->dev, client->irq, NULL,
206 max11801_ts_interrupt,
207 IRQF_TRIGGER_LOW | IRQF_ONESHOT,
208 "max11801_ts", data);
210 dev_err(&client->dev, "Failed to register interrupt\n");
214 error = input_register_device(data->input_dev);
221 static const struct i2c_device_id max11801_ts_id[] = {
225 MODULE_DEVICE_TABLE(i2c, max11801_ts_id);
227 static struct i2c_driver max11801_ts_driver = {
229 .name = "max11801_ts",
231 .id_table = max11801_ts_id,
232 .probe = max11801_ts_probe,
235 module_i2c_driver(max11801_ts_driver);
237 MODULE_AUTHOR("Zhang Jiejing <jiejing.zhang@freescale.com>");
238 MODULE_DESCRIPTION("Touchscreen driver for MAXI MAX11801 controller");
239 MODULE_LICENSE("GPL");