Merge tag 'iio-for-4.9b' of git://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio into staging-next

Jonathan writes:

Second set of iio new device support, features and cleanups for the 4.9 cycle.

New device support
* ad8801 dac
  - new driver supporting ad8801 and ad8803 DACs.
* adc12138
  - new driver supporting TI adc12130/adc12132 and adc12138 ADCs.
* ltc2485 adc
  - new driver
* mxc6255
  - add support for the mxc6225 part name and fixup the ID check so it works.
* vz89x VOC sensor
  - add support for the vz89te part which drops the voc_short channel and adds
    CRCs compared to other supported parts.

New features
* core
  - immutable triggers.  These effectively grant exclusive control over a
    trigger. The typical usecase is a device representing an analog part
    (perhaps a MUX) that needs to control the sampling of a downstream
    ADC.
  - resource managed trigger registration and triggered_buffer_init.
  - iio_push_event now protected against case of the event interface
    registration not having yet occured.  Only matters if an interrupt
    can occur during this window - might happen on shared interrupt lines.
  - helper to let a driver query if the trigger it is using is provided by
    itself (using the convention of both device and trigger having the same
    parent).
* tools
  - iio-utils. Used channel modifier scaling in preference to generic scaling
    when both exist.
* at91-adc
  - Add support for touchscreen switches closure time needed by some newer
    parts.
* stx104
  - support the ADC channels on this ADC/DAC board. As these are the primary
    feature of the board also move the driver to the iio/adc directory.
* sx9500
  - device tree bindings.

Cleanups / Fixes
* ad5755
  - fix an off-by-one on devnr limit check (introduced earlier this cycle)
* ad7266
  - drop NULL check on devm_regulator_get_optional as it can't return NULL.
* ak8974
  - avoid an unused functional warning due to rework in PM core code.
  - remove .owner field setting as done by i2c_core.
* ina2xx
  - clear out a left over debug field from chip global data.
* hid-sensors
  - avoid an unused functional warning due to rework in PM core code.
* maxim-thermocouple
  - fix non static symbol warnings.
* ms5611
  - fetch and enable regulators unconditionally when they aren't optional.
* sca3000
  - whitespace cleanup.
* st_sensors
  - fetch and enable regulators unconditionally rather than having them
    supported as optional regulators (missunderstanding on my part amongst
    others a while back)
  - followup to previous patch fixes error checking on the regulators.
  - mark symbols static where possible.
  - use the 'is it my trigger' help function.  This prevents the odd case
    of another device triggering from the st-sensors trigger whilst the
    st-sensors trigger is itself not using it but rather using say an hrtimer.
* ti-ads1015
  - add missing of_node_put.
* vz89x
  - rework to all support of new devices.
  - prevent reading of a corrupted buffer.
  - fixup a return value of 0/1 in a bool returning function.

Address updates
- Vlad Dogaru email address change.

1 files changed, 95 insertions, 0 deletions

diff --git a/drivers/iio/industrialio-trigger.c b/drivers/iio/industrialio-trigger.c
index 7ad82fdd3e5b..e1e104845e38 100644
--- a/drivers/iio/industrialio-trigger.c
+++ b/drivers/iio/industrialio-trigger.c
@@ -119,6 +119,22 @@ void iio_trigger_unregister(struct iio_trigger *trig_info)
 }
 EXPORT_SYMBOL(iio_trigger_unregister);
 
+int iio_trigger_set_immutable(struct iio_dev *indio_dev, struct iio_trigger *trig)
+{
+	if (!indio_dev || !trig)
+		return -EINVAL;
+
+	mutex_lock(&indio_dev->mlock);
+	WARN_ON(indio_dev->trig_readonly);
+
+	indio_dev->trig = iio_trigger_get(trig);
+	indio_dev->trig_readonly = true;
+	mutex_unlock(&indio_dev->mlock);
+
+	return 0;
+}
+EXPORT_SYMBOL(iio_trigger_set_immutable);
+
 /* Search for trigger by name, assuming iio_trigger_list_lock held */
 static struct iio_trigger *__iio_trigger_find_by_name(const char *name)
 {
@@ -255,6 +271,14 @@ static int iio_trigger_attach_poll_func(struct iio_trigger *trig,
 			goto out_free_irq;
 	}
 
+	/*
+	 * Check if we just registered to our own trigger: we determine that
+	 * this is the case if the IIO device and the trigger device share the
+	 * same parent device.
+	 */
+	if (pf->indio_dev->dev.parent == trig->dev.parent)
+		trig->attached_own_device = true;
+
 	return ret;
 
 out_free_irq:
@@ -279,6 +303,8 @@ static int iio_trigger_detach_poll_func(struct iio_trigger *trig,
 		if (ret)
 			return ret;
 	}
+	if (pf->indio_dev->dev.parent == trig->dev.parent)
+		trig->attached_own_device = false;
 	iio_trigger_put_irq(trig, pf->irq);
 	free_irq(pf->irq, pf);
 	module_put(pf->indio_dev->info->driver_module);
@@ -384,6 +410,10 @@ static ssize_t iio_trigger_write_current(struct device *dev,
 		mutex_unlock(&indio_dev->mlock);
 		return -EBUSY;
 	}
+	if (indio_dev->trig_readonly) {
+		mutex_unlock(&indio_dev->mlock);
+		return -EPERM;
+	}
 	mutex_unlock(&indio_dev->mlock);
 
 	trig = iio_trigger_find_by_name(buf, len);
@@ -622,6 +652,71 @@ void devm_iio_trigger_free(struct device *dev, struct iio_trigger *iio_trig)
 }
 EXPORT_SYMBOL_GPL(devm_iio_trigger_free);
 
+static void devm_iio_trigger_unreg(struct device *dev, void *res)
+{
+	iio_trigger_unregister(*(struct iio_trigger **)res);
+}
+
+/**
+ * devm_iio_trigger_register - Resource-managed iio_trigger_register()
+ * @dev:	device this trigger was allocated for
+ * @trig_info:	trigger to register
+ *
+ * Managed iio_trigger_register().  The IIO trigger registered with this
+ * function is automatically unregistered on driver detach. This function
+ * calls iio_trigger_register() internally. Refer to that function for more
+ * information.
+ *
+ * If an iio_trigger registered with this function needs to be unregistered
+ * separately, devm_iio_trigger_unregister() must be used.
+ *
+ * RETURNS:
+ * 0 on success, negative error number on failure.
+ */
+int devm_iio_trigger_register(struct device *dev, struct iio_trigger *trig_info)
+{
+	struct iio_trigger **ptr;
+	int ret;
+
+	ptr = devres_alloc(devm_iio_trigger_unreg, sizeof(*ptr), GFP_KERNEL);
+	if (!ptr)
+		return -ENOMEM;
+
+	*ptr = trig_info;
+	ret = iio_trigger_register(trig_info);
+	if (!ret)
+		devres_add(dev, ptr);
+	else
+		devres_free(ptr);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(devm_iio_trigger_register);
+
+/**
+ * devm_iio_trigger_unregister - Resource-managed iio_trigger_unregister()
+ * @dev:	device this iio_trigger belongs to
+ * @trig_info:	the trigger associated with the device
+ *
+ * Unregister trigger registered with devm_iio_trigger_register().
+ */
+void devm_iio_trigger_unregister(struct device *dev,
+				 struct iio_trigger *trig_info)
+{
+	int rc;
+
+	rc = devres_release(dev, devm_iio_trigger_unreg, devm_iio_trigger_match,
+			    trig_info);
+	WARN_ON(rc);
+}
+EXPORT_SYMBOL_GPL(devm_iio_trigger_unregister);
+
+bool iio_trigger_using_own(struct iio_dev *indio_dev)
+{
+	return indio_dev->trig->attached_own_device;
+}
+EXPORT_SYMBOL(iio_trigger_using_own);
+
 void iio_device_register_trigger_consumer(struct iio_dev *indio_dev)
 {
 	indio_dev->groups[indio_dev->groupcounter++] =