diff options
Diffstat (limited to 'drivers/input/touchscreen/max11801_ts.c')
| -rw-r--r-- | drivers/input/touchscreen/max11801_ts.c | 272 |
1 files changed, 272 insertions, 0 deletions
diff --git a/drivers/input/touchscreen/max11801_ts.c b/drivers/input/touchscreen/max11801_ts.c new file mode 100644 index 0000000..4f2713d --- /dev/null +++ b/drivers/input/touchscreen/max11801_ts.c @@ -0,0 +1,272 @@ +/* + * 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. + */ + +/* + * 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/init.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 __devinit 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 __devinit 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 = kzalloc(sizeof(struct max11801_data), GFP_KERNEL); + input_dev = input_allocate_device(); + if (!data || !input_dev) { + dev_err(&client->dev, "Failed to allocate memory\n"); + error = -ENOMEM; + goto err_free_mem; + } + + 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 = request_threaded_irq(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"); + goto err_free_mem; + } + + error = input_register_device(data->input_dev); + if (error) + goto err_free_irq; + + i2c_set_clientdata(client, data); + return 0; + +err_free_irq: + free_irq(client->irq, data); +err_free_mem: + input_free_device(input_dev); + kfree(data); + return error; +} + +static __devexit int max11801_ts_remove(struct i2c_client *client) +{ + struct max11801_data *data = i2c_get_clientdata(client); + + free_irq(client->irq, data); + input_unregister_device(data->input_dev); + kfree(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, + .remove = __devexit_p(max11801_ts_remove), +}; + +static int __init max11801_ts_init(void) +{ + return i2c_add_driver(&max11801_ts_driver); +} + +static void __exit max11801_ts_exit(void) +{ + i2c_del_driver(&max11801_ts_driver); +} + +module_init(max11801_ts_init); +module_exit(max11801_ts_exit); + +MODULE_AUTHOR("Zhang Jiejing <jiejing.zhang@freescale.com>"); +MODULE_DESCRIPTION("Touchscreen driver for MAXI MAX11801 controller"); +MODULE_LICENSE("GPL"); |
