On Mon, 11 Jan 2021 09:21:34 +0100
Lorenzo Bianconi [off-list ref] wrote:

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On Tue, 22 Dec 2020 11:53:57 +0100
Lorenzo Bianconi [off-list ref] wrote:
  

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[...]

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It's a very minor gamble, so I've applied it to the fixes-togreg branch of
iio.git.  Fingers crossed no one hits the corner case and has somehow been
getting away with it.

Thanks,  

Hi Jonathan,

I am not able to find this commit in your tree. Am I missing something?

oops. Now pushed out.

J

Regards,
Lorenzo

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Jonathan
  

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Regards,
Lorenzo
   

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It's possible we would be better falling back to interrupt free support
in that case rather than failing to probe at all.
I think that would be best done by moving the check out to the
various per type drivers so we fail in the same fashion as no irq
provided + a warning.    

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thanks,

Jonathan

   

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---
Changes since v2:
- return -EOPNOTSUPP if the drv requests edge IRQ and the sensor does not support
  status register

Changes since v1:
- return true if the sensor does not have stat_drdy register
---
 .../common/st_sensors/st_sensors_trigger.c    | 31 ++++++++++---------
 1 file changed, 17 insertions(+), 14 deletions(-)

diff --git a/drivers/iio/common/st_sensors/st_sensors_trigger.c b/drivers/iio/common/st_sensors/st_sensors_trigger.c
index 0507283bd4c1..2dbd2646e44e 100644
--- a/drivers/iio/common/st_sensors/st_sensors_trigger.c
+++ b/drivers/iio/common/st_sensors/st_sensors_trigger.c

@@ -23,35 +23,31 @@
  * @sdata: Sensor data.
  *
  * returns:
- * 0 - no new samples available
- * 1 - new samples available
- * negative - error or unknown
+ * false - no new samples available or read error
+ * true - new samples available
  */
-static int st_sensors_new_samples_available(struct iio_dev *indio_dev,
-                                         struct st_sensor_data *sdata)
+static bool st_sensors_new_samples_available(struct iio_dev *indio_dev,
+                                          struct st_sensor_data *sdata)
 {
      int ret, status;

      /* How would I know if I can't check it? */
      if (!sdata->sensor_settings->drdy_irq.stat_drdy.addr)
-             return -EINVAL;
+             return true;

      /* No scan mask, no interrupt */
      if (!indio_dev->active_scan_mask)
-             return 0;
+             return false;

      ret = regmap_read(sdata->regmap,
                        sdata->sensor_settings->drdy_irq.stat_drdy.addr,
                        &status);
      if (ret < 0) {
              dev_err(sdata->dev, "error checking samples available\n");
-             return ret;
+             return false;
      }

-     if (status & sdata->sensor_settings->drdy_irq.stat_drdy.mask)
-             return 1;
-
-     return 0;
+     return !!(status & sdata->sensor_settings->drdy_irq.stat_drdy.mask);    

No need for the !! as you can rely on type conversion to a boolean.
   

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 }

 /**

@@ -180,9 +176,15 @@ int st_sensors_allocate_trigger(struct iio_dev *indio_dev,

      /* Tell the interrupt handler that we're dealing with edges */
      if (irq_trig == IRQF_TRIGGER_FALLING ||
-         irq_trig == IRQF_TRIGGER_RISING)
+         irq_trig == IRQF_TRIGGER_RISING) {
+             if (!sdata->sensor_settings->drdy_irq.stat_drdy.addr) {
+                     dev_err(&indio_dev->dev,
+                             "edge IRQ not supported w/o stat register.\n");
+                     err = -EOPNOTSUPP;
+                     goto iio_trigger_free;
+             }
              sdata->edge_irq = true;
-     else
+     } else {
              /*
               * If we're not using edges (i.e. level interrupts) we
               * just mask off the IRQ, handle one interrupt, then

@@ -190,6 +192,7 @@ int st_sensors_allocate_trigger(struct iio_dev *indio_dev,
               * interrupt handler top half again and start over.
               */
              irq_trig |= IRQF_ONESHOT;
+     }

      /*
       * If the interrupt pin is Open Drain, by definition this