#include <linux/iio/common/st_sensors.h>
#include "st_sensors_core.h"
+/**
+ * st_sensors_new_samples_available() - check if more samples came in
+ * returns:
+ * 0 - no new samples available
+ * 1 - new samples available
+ * negative - error or unknown
+ */
+static int st_sensors_new_samples_available(struct iio_dev *indio_dev,
+ struct st_sensor_data *sdata)
+{
+ u8 status;
+ int ret;
+
+ /* How would I know if I can't check it? */
+ if (!sdata->sensor_settings->drdy_irq.addr_stat_drdy)
+ return -EINVAL;
+
+ /* No scan mask, no interrupt */
+ if (!indio_dev->active_scan_mask)
+ return 0;
+
+ ret = sdata->tf->read_byte(&sdata->tb, sdata->dev,
+ sdata->sensor_settings->drdy_irq.addr_stat_drdy,
+ &status);
+ if (ret < 0) {
+ dev_err(sdata->dev,
+ "error checking samples available\n");
+ return ret;
+ }
+ /*
+ * the lower bits of .active_scan_mask[0] is directly mapped
+ * to the channels on the sensor: either bit 0 for
+ * one-dimensional sensors, or e.g. x,y,z for accelerometers,
+ * gyroscopes or magnetometers. No sensor use more than 3
+ * channels, so cut the other status bits here.
+ */
+ status &= 0x07;
+
+ if (status & (u8)indio_dev->active_scan_mask[0])
+ return 1;
+
+ return 0;
+}
+
/**
* st_sensors_irq_handler() - top half of the IRQ-based triggers
* @irq: irq number
struct iio_trigger *trig = p;
struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
struct st_sensor_data *sdata = iio_priv(indio_dev);
- int ret;
/*
* If this trigger is backed by a hardware interrupt and we have a
- * status register, check if this IRQ came from us
+ * status register, check if this IRQ came from us. Notice that
+ * we will process also if st_sensors_new_samples_available()
+ * returns negative: if we can't check status, then poll
+ * unconditionally.
*/
- if (sdata->sensor_settings->drdy_irq.addr_stat_drdy) {
- u8 status;
-
- ret = sdata->tf->read_byte(&sdata->tb, sdata->dev,
- sdata->sensor_settings->drdy_irq.addr_stat_drdy,
- &status);
- if (ret < 0) {
- dev_err(sdata->dev, "could not read channel status\n");
- goto out_poll;
- }
- /*
- * the lower bits of .active_scan_mask[0] is directly mapped
- * to the channels on the sensor: either bit 0 for
- * one-dimensional sensors, or e.g. x,y,z for accelerometers,
- * gyroscopes or magnetometers. No sensor use more than 3
- * channels, so cut the other status bits here.
- */
- status &= 0x07;
+ if (sdata->hw_irq_trigger &&
+ st_sensors_new_samples_available(indio_dev, sdata)) {
+ iio_trigger_poll_chained(p);
+ } else {
+ dev_dbg(sdata->dev, "spurious IRQ\n");
+ return IRQ_NONE;
+ }
- /*
- * If this was not caused by any channels on this sensor,
- * return IRQ_NONE
- */
- if (!indio_dev->active_scan_mask)
- return IRQ_NONE;
- if (!(status & (u8)indio_dev->active_scan_mask[0]))
- return IRQ_NONE;
+ /*
+ * If we have proper level IRQs the handler will be re-entered if
+ * the line is still active, so return here and come back in through
+ * the top half if need be.
+ */
+ if (!sdata->edge_irq)
+ return IRQ_HANDLED;
+
+ /*
+ * If we are using egde IRQs, new samples arrived while processing
+ * the IRQ and those may be missed unless we pick them here, so poll
+ * again. If the sensor delivery frequency is very high, this thread
+ * turns into a polled loop handler.
+ */
+ while (sdata->hw_irq_trigger &&
+ st_sensors_new_samples_available(indio_dev, sdata)) {
+ dev_dbg(sdata->dev, "more samples came in during polling\n");
+ sdata->hw_timestamp = iio_get_time_ns(indio_dev);
+ iio_trigger_poll_chained(p);
}
-out_poll:
- /* It's our IRQ: proceed to handle the register polling */
- iio_trigger_poll_chained(p);
return IRQ_HANDLED;
}
* 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) {
+ switch(irq_trig) {
+ case IRQF_TRIGGER_FALLING:
+ case IRQF_TRIGGER_LOW:
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;
+ "falling/low specified for IRQ "
+ "but hardware only support rising/high: "
+ "will request rising/high\n");
+ if (irq_trig == IRQF_TRIGGER_FALLING)
+ irq_trig = IRQF_TRIGGER_RISING;
+ if (irq_trig == IRQF_TRIGGER_LOW)
+ irq_trig = IRQF_TRIGGER_HIGH;
} else {
/* Set up INT active low i.e. falling edge */
err = st_sensors_write_data_with_mask(indio_dev,
if (err < 0)
goto iio_trigger_free;
dev_info(&indio_dev->dev,
- "interrupts on the falling edge\n");
+ "interrupts on the falling edge or "
+ "active low level\n");
}
- } else if (irq_trig == IRQF_TRIGGER_RISING) {
+ break;
+ case IRQF_TRIGGER_RISING:
dev_info(&indio_dev->dev,
"interrupts on the rising edge\n");
-
- } else {
+ break;
+ case IRQF_TRIGGER_HIGH:
+ dev_info(&indio_dev->dev,
+ "interrupts active high level\n");
+ break;
+ default:
+ /* This is the most preferred mode, if possible */
dev_err(&indio_dev->dev,
- "unsupported IRQ trigger specified (%lx), only "
- "rising and falling edges supported, enforce "
+ "unsupported IRQ trigger specified (%lx), enforce "
"rising edge\n", irq_trig);
irq_trig = IRQF_TRIGGER_RISING;
}
+ /* Tell the interrupt handler that we're dealing with edges */
+ if (irq_trig == IRQF_TRIGGER_FALLING ||
+ irq_trig == IRQF_TRIGGER_RISING)
+ sdata->edge_irq = true;
+ else
+ /*
+ * If we're not using edges (i.e. level interrupts) we
+ * just mask off the IRQ, handle one interrupt, then
+ * if the line is still low, we return to the
+ * interrupt handler top half again and start over.
+ */
+ irq_trig |= IRQF_ONESHOT;
+
/*
* If the interrupt pin is Open Drain, by definition this
* means that the interrupt line may be shared with other
sdata->sensor_settings->drdy_irq.addr_stat_drdy)
irq_trig |= IRQF_SHARED;
- /* Let's create an interrupt thread masking the hard IRQ here */
- irq_trig |= IRQF_ONESHOT;
-
err = request_threaded_irq(sdata->get_irq_data_ready(indio_dev),
st_sensors_irq_handler,
st_sensors_irq_thread,
projects / karo-tx-linux.git / commitdiff