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a9fd053b56
Most ST MEMS Sensors that support interrupts can also handle sending an active low interrupt, i.e. going from high to low on data ready (or other interrupt) and thus triggering on a falling edge to the interrupt controller. Set up logic to inspect the interrupt line we get for a sensor: if it is triggering on rising edge, leave everything alone, but if it triggers on falling edges, set up active low, and if unsupported configurations appear: warn with errors and reconfigure the interrupt to a rising edge, which all interrupt generating sensors support. Create a local header for st_sensors_core.h to share functions between the sensor core and the trigger setup code. Cc: Giuseppe Barba <giuseppe.barba@st.com> Cc: Denis Ciocca <denis.ciocca@st.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
112 lines
3.1 KiB
C
112 lines
3.1 KiB
C
/*
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* STMicroelectronics sensors trigger library driver
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*
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* Copyright 2012-2013 STMicroelectronics Inc.
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*
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* Denis Ciocca <denis.ciocca@st.com>
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*
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* Licensed under the GPL-2.
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/slab.h>
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#include <linux/iio/iio.h>
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#include <linux/iio/trigger.h>
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#include <linux/interrupt.h>
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#include <linux/iio/common/st_sensors.h>
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#include "st_sensors_core.h"
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int st_sensors_allocate_trigger(struct iio_dev *indio_dev,
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const struct iio_trigger_ops *trigger_ops)
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{
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int err, irq;
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struct st_sensor_data *sdata = iio_priv(indio_dev);
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unsigned long irq_trig;
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sdata->trig = iio_trigger_alloc("%s-trigger", indio_dev->name);
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if (sdata->trig == NULL) {
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dev_err(&indio_dev->dev, "failed to allocate iio trigger.\n");
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return -ENOMEM;
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}
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irq = sdata->get_irq_data_ready(indio_dev);
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irq_trig = irqd_get_trigger_type(irq_get_irq_data(irq));
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/*
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* If the IRQ is triggered on falling edge, we need to mark the
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* interrupt as active low, if the hardware supports this.
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*/
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if (irq_trig == IRQF_TRIGGER_FALLING) {
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if (!sdata->sensor_settings->drdy_irq.addr_ihl) {
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dev_err(&indio_dev->dev,
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"falling edge specified for IRQ but hardware "
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"only support rising edge, will request "
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"rising edge\n");
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irq_trig = IRQF_TRIGGER_RISING;
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} else {
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/* Set up INT active low i.e. falling edge */
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err = st_sensors_write_data_with_mask(indio_dev,
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sdata->sensor_settings->drdy_irq.addr_ihl,
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sdata->sensor_settings->drdy_irq.mask_ihl, 1);
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if (err < 0)
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goto iio_trigger_free;
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dev_info(&indio_dev->dev,
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"interrupts on the falling edge\n");
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}
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} else if (irq_trig == IRQF_TRIGGER_RISING) {
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dev_info(&indio_dev->dev,
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"interrupts on the rising edge\n");
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} else {
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dev_err(&indio_dev->dev,
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"unsupported IRQ trigger specified (%lx), only "
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"rising and falling edges supported, enforce "
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"rising edge\n", irq_trig);
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irq_trig = IRQF_TRIGGER_RISING;
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}
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err = request_threaded_irq(irq,
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iio_trigger_generic_data_rdy_poll,
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NULL,
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irq_trig,
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sdata->trig->name,
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sdata->trig);
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if (err) {
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dev_err(&indio_dev->dev, "failed to request trigger IRQ.\n");
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goto iio_trigger_free;
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}
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iio_trigger_set_drvdata(sdata->trig, indio_dev);
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sdata->trig->ops = trigger_ops;
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sdata->trig->dev.parent = sdata->dev;
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err = iio_trigger_register(sdata->trig);
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if (err < 0) {
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dev_err(&indio_dev->dev, "failed to register iio trigger.\n");
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goto iio_trigger_register_error;
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}
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indio_dev->trig = iio_trigger_get(sdata->trig);
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return 0;
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iio_trigger_register_error:
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free_irq(sdata->get_irq_data_ready(indio_dev), sdata->trig);
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iio_trigger_free:
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iio_trigger_free(sdata->trig);
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return err;
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}
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EXPORT_SYMBOL(st_sensors_allocate_trigger);
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void st_sensors_deallocate_trigger(struct iio_dev *indio_dev)
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{
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struct st_sensor_data *sdata = iio_priv(indio_dev);
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iio_trigger_unregister(sdata->trig);
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free_irq(sdata->get_irq_data_ready(indio_dev), sdata->trig);
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iio_trigger_free(sdata->trig);
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}
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EXPORT_SYMBOL(st_sensors_deallocate_trigger);
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MODULE_AUTHOR("Denis Ciocca <denis.ciocca@st.com>");
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MODULE_DESCRIPTION("STMicroelectronics ST-sensors trigger");
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MODULE_LICENSE("GPL v2");
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