diff options
Diffstat (limited to 'drivers/input/touchscreen/imx_adc_ts.c')
-rw-r--r-- | drivers/input/touchscreen/imx_adc_ts.c | 114 |
1 files changed, 114 insertions, 0 deletions
diff --git a/drivers/input/touchscreen/imx_adc_ts.c b/drivers/input/touchscreen/imx_adc_ts.c new file mode 100644 index 000000000000..797eff5672dc --- /dev/null +++ b/drivers/input/touchscreen/imx_adc_ts.c @@ -0,0 +1,114 @@ +/* + * Copyright 2009-2010 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"); |