iio: trigger: allow devices to suspend/resume theirs associated trigger

When a machine enters a sleep state while a trigger is associated to
an iio device that trigger is not resumed after exiting the sleep state:
provide iio device drivers a way to suspend and resume
the associated trigger to solve the aforementioned bug.

Each iio driver supporting external triggers is expected to call
iio_device_suspend_triggering before suspending,
and iio_device_resume_triggering upon resuming.

Signed-off-by: Denis Benato <benato.denis96@gmail.com>
Link: https://patch.msgid.link/20240807185619.7261-2-benato.denis96@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

diff --git a/drivers/iio/industrialio-trigger.c b/drivers/iio/industrialio-trigger.c
index 2e84776f4fbd4d80d695c75934514372f90c2fa3..54416a384232b3bb1f0b492c3552f29c74999cd6 100644 (file)
--- a/drivers/iio/industrialio-trigger.c
+++ b/drivers/iio/industrialio-trigger.c
@@ -347,6 +347,7 @@ int iio_trigger_detach_poll_func(struct iio_trigger *trig,
        iio_trigger_put_irq(trig, pf->irq);
        free_irq(pf->irq, pf);
        module_put(iio_dev_opaque->driver_module);
+       pf->irq = 0;
 
        return ret;
 }
@@ -770,3 +771,29 @@ void iio_device_unregister_trigger_consumer(struct iio_dev *indio_dev)
        if (indio_dev->trig)
                iio_trigger_put(indio_dev->trig);
 }
+
+int iio_device_suspend_triggering(struct iio_dev *indio_dev)
+{
+       struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
+
+       guard(mutex)(&iio_dev_opaque->mlock);
+
+       if ((indio_dev->pollfunc) && (indio_dev->pollfunc->irq > 0))
+               disable_irq(indio_dev->pollfunc->irq);
+
+       return 0;
+}
+EXPORT_SYMBOL(iio_device_suspend_triggering);
+
+int iio_device_resume_triggering(struct iio_dev *indio_dev)
+{
+       struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
+
+       guard(mutex)(&iio_dev_opaque->mlock);
+
+       if ((indio_dev->pollfunc) && (indio_dev->pollfunc->irq > 0))
+               enable_irq(indio_dev->pollfunc->irq);
+
+       return 0;
+}
+EXPORT_SYMBOL(iio_device_resume_triggering);

diff --git a/include/linux/iio/iio.h b/include/linux/iio/iio.h
index 3a735a9a9eae4e2f142858428e693fd0c499590f..18779b631e9071801958fc9d50b941b548fab940 100644 (file)
--- a/include/linux/iio/iio.h
+++ b/include/linux/iio/iio.h
@@ -810,6 +810,23 @@ static inline struct dentry *iio_get_debugfs_dentry(struct iio_dev *indio_dev)
 }
 #endif
 
+/**
+ * iio_device_suspend_triggering() - suspend trigger attached to an iio_dev
+ * @indio_dev: iio_dev associated with the device that will have triggers suspended
+ *
+ * Return 0 if successful, negative otherwise
+ **/
+int iio_device_suspend_triggering(struct iio_dev *indio_dev);
+
+/**
+ * iio_device_resume_triggering() - resume trigger attached to an iio_dev
+ *     that was previously suspended with iio_device_suspend_triggering()
+ * @indio_dev: iio_dev associated with the device that will have triggers resumed
+ *
+ * Return 0 if successful, negative otherwise
+ **/
+int iio_device_resume_triggering(struct iio_dev *indio_dev);
+
 #ifdef CONFIG_ACPI
 bool iio_read_acpi_mount_matrix(struct device *dev,
                                struct iio_mount_matrix *orientation,