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.
16
* This driver aims to support the series of MAXI touch chips max11801
17
* through max11803. The main difference between these 4 chips can be
18
* found in the table below:
19
* -----------------------------------------------------
20
* | CHIP | AUTO MODE SUPPORT(FIFO) | INTERFACE |
21
* |----------------------------------------------------|
22
* | max11800 | YES | SPI |
23
* | max11801 | YES | I2C |
24
* | max11802 | NO | SPI |
25
* | max11803 | NO | I2C |
26
* ------------------------------------------------------
28
* Currently, this driver only supports max11801.
31
* http://www.maxim-ic.com/datasheet/index.mvp/id/5943
34
#include <linux/module.h>
35
#include <linux/init.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 __devinit 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 __devinit 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 = kzalloc(sizeof(struct max11801_data), GFP_KERNEL);
184
input_dev = input_allocate_device();
185
if (!data || !input_dev) {
186
dev_err(&client->dev, "Failed to allocate memory\n");
191
data->client = client;
192
data->input_dev = input_dev;
194
input_dev->name = "max11801_ts";
195
input_dev->id.bustype = BUS_I2C;
196
input_dev->dev.parent = &client->dev;
198
__set_bit(EV_ABS, input_dev->evbit);
199
__set_bit(EV_KEY, input_dev->evbit);
200
__set_bit(BTN_TOUCH, input_dev->keybit);
201
input_set_abs_params(input_dev, ABS_X, 0, MAX11801_MAX_X, 0, 0);
202
input_set_abs_params(input_dev, ABS_Y, 0, MAX11801_MAX_Y, 0, 0);
203
input_set_drvdata(input_dev, data);
205
max11801_ts_phy_init(data);
207
error = request_threaded_irq(client->irq, NULL, max11801_ts_interrupt,
208
IRQF_TRIGGER_LOW | IRQF_ONESHOT,
209
"max11801_ts", data);
211
dev_err(&client->dev, "Failed to register interrupt\n");
215
error = input_register_device(data->input_dev);
219
i2c_set_clientdata(client, data);
223
free_irq(client->irq, data);
225
input_free_device(input_dev);
230
static __devexit int max11801_ts_remove(struct i2c_client *client)
232
struct max11801_data *data = i2c_get_clientdata(client);
234
free_irq(client->irq, data);
235
input_unregister_device(data->input_dev);
241
static const struct i2c_device_id max11801_ts_id[] = {
245
MODULE_DEVICE_TABLE(i2c, max11801_ts_id);
247
static struct i2c_driver max11801_ts_driver = {
249
.name = "max11801_ts",
250
.owner = THIS_MODULE,
252
.id_table = max11801_ts_id,
253
.probe = max11801_ts_probe,
254
.remove = __devexit_p(max11801_ts_remove),
257
static int __init max11801_ts_init(void)
259
return i2c_add_driver(&max11801_ts_driver);
262
static void __exit max11801_ts_exit(void)
264
i2c_del_driver(&max11801_ts_driver);
267
module_init(max11801_ts_init);
268
module_exit(max11801_ts_exit);
270
MODULE_AUTHOR("Zhang Jiejing <jiejing.zhang@freescale.com>");
271
MODULE_DESCRIPTION("Touchscreen driver for MAXI MAX11801 controller");
272
MODULE_LICENSE("GPL");