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/*
* Copyright 2009 Freescale Semiconductor, Inc. All Rights Reserved.
*/
/*
* The code contained herein is licensed under the GNU General Public
* License. You may obtain a copy of the GNU General Public License
* Version 2 or later at the following locations:
*
* http://www.opensource.org/licenses/gpl-license.html
* http://www.gnu.org/copyleft/gpl.html
*/
/*!
* @file imx_adc_ts.c
*
* @brief Driver for the Freescale Semiconductor i.MX ADC touchscreen.
*
* This touchscreen driver is designed as a standard input driver. It is a
* wrapper around the low level ADC driver. Much of the hardware configuration
* and touchscreen functionality is implemented in the low level ADC driver.
* During initialization, this driver creates a kernel thread. This thread
* then calls the ADC driver to obtain touchscreen values continously. These
* values are then passed to the input susbsystem.
*
* @ingroup touchscreen
*/
#include <linux/kernel.h>
#include <linux/kthread.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/input.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/freezer.h>
#include <linux/imx_adc.h>
#define IMX_ADC_TS_NAME "imx_adc_ts"
static struct input_dev *imx_inputdev;
static u32 input_ts_installed;
static int ts_thread(void *arg)
{
struct t_touch_screen ts_sample;
int wait = 0;
daemonize("imx_adc_ts");
while (input_ts_installed) {
try_to_freeze();
memset(&ts_sample, 0, sizeof(ts_sample));
if (0 != imx_adc_get_touch_sample(&ts_sample, !wait))
continue;
input_report_abs(imx_inputdev, ABS_X, ts_sample.x_position);
input_report_abs(imx_inputdev, ABS_Y, ts_sample.y_position);
input_report_abs(imx_inputdev, ABS_PRESSURE,
ts_sample.contact_resistance);
input_sync(imx_inputdev);
wait = ts_sample.contact_resistance;
msleep(10);
}
return 0;
}
static int __init imx_adc_ts_init(void)
{
int retval;
if (!is_imx_adc_ready())
return -ENODEV;
imx_inputdev = input_allocate_device();
if (!imx_inputdev) {
pr_err("imx_ts_init: not enough memory for input device\n");
return -ENOMEM;
}
imx_inputdev->name = IMX_ADC_TS_NAME;
imx_inputdev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
imx_inputdev->keybit[BIT_WORD(BTN_TOUCH)] |= BIT_MASK(BTN_TOUCH);
imx_inputdev->absbit[0] =
BIT_MASK(ABS_X) | BIT_MASK(ABS_Y) | BIT_MASK(ABS_PRESSURE);
retval = input_register_device(imx_inputdev);
if (retval < 0) {
input_free_device(imx_inputdev);
return retval;
}
input_ts_installed = 1;
kthread_run(ts_thread, NULL, "ts_thread");
pr_info("i.MX ADC input touchscreen loaded.\n");
return 0;
}
static void __exit imx_adc_ts_exit(void)
{
input_ts_installed = 0;
input_unregister_device(imx_inputdev);
if (imx_inputdev) {
input_free_device(imx_inputdev);
imx_inputdev = NULL;
}
}
late_initcall(imx_adc_ts_init);
module_exit(imx_adc_ts_exit);
MODULE_DESCRIPTION("i.MX ADC input touchscreen driver");
MODULE_AUTHOR("Freescale Semiconductor, Inc.");
MODULE_LICENSE("GPL");
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