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/*
* STMicroelectronics sensors trigger library driver
*
* Copyright 2012-2013 STMicroelectronics Inc.
*
* Denis Ciocca <denis.ciocca@st.com>
*
* Licensed under the GPL-2.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/iio/iio.h>
#include <linux/iio/trigger.h>
#include <linux/interrupt.h>
#include <linux/iio/common/st_sensors.h>
#include "st_sensors_core.h"
int st_sensors_allocate_trigger(struct iio_dev *indio_dev,
const struct iio_trigger_ops *trigger_ops)
{
int err, irq;
struct st_sensor_data *sdata = iio_priv(indio_dev);
unsigned long irq_trig;
sdata->trig = iio_trigger_alloc("%s-trigger", indio_dev->name);
if (sdata->trig == NULL) {
dev_err(&indio_dev->dev, "failed to allocate iio trigger.\n");
return -ENOMEM;
}
irq = sdata->get_irq_data_ready(indio_dev);
irq_trig = irqd_get_trigger_type(irq_get_irq_data(irq));
/*
* If the IRQ is triggered on falling edge, we need to mark the
* interrupt as active low, if the hardware supports this.
*/
if (irq_trig == IRQF_TRIGGER_FALLING) {
if (!sdata->sensor_settings->drdy_irq.addr_ihl) {
dev_err(&indio_dev->dev,
"falling edge specified for IRQ but hardware "
"only support rising edge, will request "
"rising edge\n");
irq_trig = IRQF_TRIGGER_RISING;
} else {
/* Set up INT active low i.e. falling edge */
err = st_sensors_write_data_with_mask(indio_dev,
sdata->sensor_settings->drdy_irq.addr_ihl,
sdata->sensor_settings->drdy_irq.mask_ihl, 1);
if (err < 0)
goto iio_trigger_free;
dev_info(&indio_dev->dev,
"interrupts on the falling edge\n");
}
} else if (irq_trig == IRQF_TRIGGER_RISING) {
dev_info(&indio_dev->dev,
"interrupts on the rising edge\n");
} else {
dev_err(&indio_dev->dev,
"unsupported IRQ trigger specified (%lx), only "
"rising and falling edges supported, enforce "
"rising edge\n", irq_trig);
irq_trig = IRQF_TRIGGER_RISING;
}
/*
* If the interrupt pin is Open Drain, by definition this
* means that the interrupt line may be shared with other
* peripherals. But to do this we also need to have a status
* register and mask to figure out if this sensor was firing
* the IRQ or not, so we can tell the interrupt handle that
* it was "our" interrupt.
*/
if (sdata->int_pin_open_drain &&
sdata->sensor_settings->drdy_irq.addr_stat_drdy)
irq_trig |= IRQF_SHARED;
err = request_threaded_irq(irq,
iio_trigger_generic_data_rdy_poll,
NULL,
irq_trig,
sdata->trig->name,
sdata->trig);
if (err) {
dev_err(&indio_dev->dev, "failed to request trigger IRQ.\n");
goto iio_trigger_free;
}
iio_trigger_set_drvdata(sdata->trig, indio_dev);
sdata->trig->ops = trigger_ops;
sdata->trig->dev.parent = sdata->dev;
err = iio_trigger_register(sdata->trig);
if (err < 0) {
dev_err(&indio_dev->dev, "failed to register iio trigger.\n");
goto iio_trigger_register_error;
}
indio_dev->trig = iio_trigger_get(sdata->trig);
return 0;
iio_trigger_register_error:
free_irq(sdata->get_irq_data_ready(indio_dev), sdata->trig);
iio_trigger_free:
iio_trigger_free(sdata->trig);
return err;
}
EXPORT_SYMBOL(st_sensors_allocate_trigger);
void st_sensors_deallocate_trigger(struct iio_dev *indio_dev)
{
struct st_sensor_data *sdata = iio_priv(indio_dev);
iio_trigger_unregister(sdata->trig);
free_irq(sdata->get_irq_data_ready(indio_dev), sdata->trig);
iio_trigger_free(sdata->trig);
}
EXPORT_SYMBOL(st_sensors_deallocate_trigger);
MODULE_AUTHOR("Denis Ciocca <denis.ciocca@st.com>");
MODULE_DESCRIPTION("STMicroelectronics ST-sensors trigger");
MODULE_LICENSE("GPL v2");
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