[PATCH v15 00/32] Unified fwnode endpoint parser, async sub-device notifier support, N9 flash DTS

[PATCH v15 00/32] Unified fwnode endpoint parser, async sub-device notifier support, N9 flash DTS

[Sakari Ailus]

Hi folks,

	I've dropped the full set from devicetree and linux-acpi lists;
	let me know if you want it back. The entire set is posted to
	linux-media list.

We have a large influx of new, unmerged, drivers that are now parsing
fwnode endpoints and each one of them is doing this a little bit
differently. The needs are still exactly the same for the graph data
structure is device independent. This is still a non-trivial task and the
majority of the driver implementations are buggy, just buggy in different
ways.

Facilitate parsing endpoints by adding a convenience function for parsing
the endpoints, and make the omap3isp and rcar-vin drivers use them as an
example.

To show where we're getting with this, I've added support for async
sub-device notifier support that is notifiers that can be registered by
sub-device drivers as well as V4L2 fwnode improvements to make use of them
and the DTS changes for the Nokia N9. Some of these patches I've posted
previously in this set here:

<URL:http://www.spinics.net/lists/linux-media/msg118764.html>

Since that, the complete callback of the master notifier registering the
V4L2 device is only called once all sub-notifiers have been completed as
well. This way the device node creation can be postponed until all devices
have been successfully initialised.

With this, the as3645a driver successfully registers a sub-device to the
media device created by the omap3isp driver. The kernel also has the
information it's related to the sensor driven by the smiapp driver but we
don't have a way to expose that information yet.

The patches have a dependency to the as3645a driver fixes:

<URL:https://git.kernel.org/pub/scm/linux/kernel/git/j.anaszewski/linux-leds.git/log/?h=fixes-4.14-rc3>

since v14:

- Patch "v4l: fwnode: Support generic parsing of graph endpoints in a
  device" depends on another patch "device property: preserve usecount for
  node passed to of_fwnode_graph_get_port_parent()". Add Depends-on tag.

- Add patch "v4l: async: fix unbind error in
  v4l2_async_notifier_unregister()" by Niklas. Effectively the notifier's
  unbind callback is called before v4l2_async_cleanup(), not after it.

- Fix complete callback error handling (patch "v4l: async: Fix notifier
  complete callback error handling").

- Rework error handling in in v4l2_async_match_notify() and add comments.
  No functional changes there.

- Don't assign sd->dev to NULL in v4l2_async_cleanup() (patch "v4l: async:
  Don't set sd->dev NULL in v4l2_async_cleanup").

- Introduce a function to unbind sub-devices from a notifier. This is a
  common operation so a common implementation is beneficial.

- Assign notifier's v4l2_dev (or sd for sub-device notifiers) NULL on
  failure.

- Make v4l2_async_notifier_unregister() safe to call with a NULL argument.

- Set the implicitly allocated sub-device notifier NULL on async
  sub-device unregistration (used to be a dangling pointer).

- Clean up async sub-device unregistration.

- Fix v4l2_fwnode_endpoint_free() comment to match KernelDoc style, i.e.
  make the function visible in documentation.

- Don't add a random newline near the end of v4l2_async.h.

- Move patch "v4l: fwnode: Move KernelDoc documentation to the header"
  later in the set. The five first patches should now address bugs in the
  V4L2 async framework, causing an oops on complete callback failure.

since v13:

- Add patch "v4l: fwnode: Add a convenience function for registering sensors"
  and make the sensor driver changes a lot smaller.

- Fix v4l2_async_notifier_parse_fwnode_endpoints() error handling for
  omap3isp.

- Return -ENODEV in rcar-vin if no async sub-device is available. I.e. fix
  a bug in previous versions of "rcar-vin: Use generic parser for parsing
  fwnode endpoints".

- Rework notifier completion in patch "v4l: async: Allow binding notifiers to
  sub-devices". This fixes calling complete notifiers more than once; they
  are now all called once when all async sub-devices in all related
  notifiers have been bound.

- Split the same patch ("v4l: async: Allow binding notifiers to
  sub-devices") into two, first one that prepares for async sub-devices
  and another that implements the bulk of support for sub-device notifiers.

- Postpone sub-device bound callback until v4l2_device is available in all
  cases. This also applies to the media device. The notifier's bound
  callback was in some cases called before having v4l2_device in v13.

- Prevent registering fwnodes as async sub-devices more than once.

- Use list_move instead of list_del and list_add in
  v4l2_async_notifier_unbind_all_subdevs.

- Call v4l2_async_notifier_release v4l2_async_notifier_cleanup instead.
  It's a cleanup function and does not release the object passed to it.

- In v4l2_async_notifier_fwnode_parse_endpoint, set match_type field with
  the fwnode.fwnode field, not later.

- In debug and other messages, use port@number/endpoint@number format.

- Call fwnode_handle_put() to release references obtained using e.g.
  fwnode_graph_get_port_parent.

- Multiple KernelDoc documentation fixes.

since v12:

- Merge patches "v4l: fwnode: Support generic parsing of graph endpoints
  in a device" and "v4l: fwnode: Support generic parsing of graph
  endpoints, per port". Improve the commit and KernelDoc documentation as
  well.

- Reformat loop conditions in v4l2_async_notifier_try_complete() and
  v4l2_fwnode_reference_get_int_prop(). Improve comments in
  fwnode_property_get_reference_args() return value handling. Also check
  for -ENODATA in v4l2_fwnode_reference_parse_int_props().

- Add an ACPI example for v4l2_fwnode_reference_get_int_prop().

- Document index parameter, document nprops parameter better and fix
  -EINVAL error code documentation for
  v4l2_fwnode_reference_get_int_prop().

- Use WARN_ON_ONCE(true) instead of WARN_ON_ONCE(1) in
  v4l2_async_notifier_release().

since v11:

- Add patch "et8ek8: Add support for flash and lens devices".

- Add patch "v4l: fwnode: Support generic parsing of graph endpoints, per
  port". The use case for this is to parse only upstream ports in a device
  with sources and sinks. The downstream ports have already been parsed by
  other drivers.

- Rename v4l2_fwnode_reference_parse_sensor_common as
  v4l2_async_notifier_parse_fwnode_sensor_common. This is in line with
  other functions that parse information using fwnode API and set up async
  sub-devices in the notifier.

since v10:

- Rename v4l2_async_get_subdev_notifier as
  v4l2_async_find_subdev_notifier, as this is what it effectively does:
  finds a notifier for a sub-device. Same for v4l2_async_notifier_get_v4l2_dev
  / v4l2_async_notifier_get_v4l2_dev.

- Initialise lists before calling v4l2_async_notifier_call_complete() if
  there are no sub-devices in a notifier.

- Warn on missing sub-device or existing v4l2_device on sub-device
  notifier register, and conversely missing v4l2_device or existing
  sub-device for a master notifier.

- Set notifier's sd and v4l2_dev fields NULL when the sub-device is
  unregistered.

- Document the newly added helper functions for parsing external
  references in v4l2-fwnode.c better.

- Return -ENOENT in v4l2_fwnode_reference_parse if no entries are found,
  and other errors as they occur.

- Turn the loop in v4l2_fwnode_reference_get_int_prop a while loop (was
  for).

- Don't put fwnodes in v4l2_fwnode_reference_parse_int_props.

- Fix description of parent field in struct v4l2_async_notifier.

- In the documentation of v4l2_async_notifier_release, document that this
  function must be called also after
  v4l2_fwnode_reference_parse_sensor_common, not just
  v4l2_async_notifier_parse_fwnode_endpoints. The same goes for
  v4l2_async_notifier_parse_fwnode_endpoints as well as
  v4l2_fwnode_reference_parse_sensor_common.

since v9:

- Drop "as3645a: Switch to fwnode property API" and "ACPI: Document how to
  refer to LEDs from remote nodes" patches. They're better off separately
  from this set.

- Address property documentation redundancy in smiapp DT binding
  documentation.

- Add patches "ov5670: Add support for flash and lens devices" and
  "ov13858: Add support for flash and lens devices".

since v8:

- Improve terminology for notifiers. Instead of master / subdev, we
  have root, parent and subdev notifiers.

- Renamed "flash" property as "flash-leds". There are many, and currently
  we make assumptions in a lot of places (e.g. LED bindings) that these
  are LEDs. While we don't have any other types of flashes supported right
  now (e.g. Xenon), it's safer to assume we might have them in the future.

- Use ENOTCONN instead of EPERM to tell from driver's callback function
  that an endpoint is to be skipped but not handled as an error.

- Avoid accessing notifier's subdevs array as well as num_subdevs field
  from rcar-vin driver.

- Add a patch "v4l: async: Allow async notifier register call succeed with no
  subdevs", which allows, well, what the subject says.

- Move checks for subdev / v4l2_dev from __v4l2_async_notifier_register()
  to v4l2_async_notifier_register() and
  v4l2_async_subdev_notifier_register().

- Don't initialise notifier->list. There was no need to do so, as this is
  the entry added to the list and not used otherwise. I.e. regarding this,
  the state before this patchset is restored.

- Clean up error handling in v4l2_async_notifier_fwnode_parse_endpoint().

- WARN_ON() in v4l2_async_notifier_parse_fwnode_endpoints() if the
  asd_struct_size is smaller than size of struct v4l2_async_subdev.

- Make v4l2_fwnode_reference_parse() static as there should be no need to
  use it outside the V4L2 fwnode framework. Also, remove the callback
  function as well as other arguments that always have the same value in
  current usage. (This can be changed later on if needed without affecting
  drivers.)

- Add the patch "v4l: fwnode: Add a helper function to obtain device /
  interger references", which allows similar use than
  v4l2_fwnode_reference_parse() but is more useful on ACPI based systems
  --- on ACPI, you can only refer to device nodes (corresponding struct
  deice in Linux), not to data extension nodes under the devices.

- Improve v4l2_fwnode_reference_parse_sensor_common() to work on ACPI
  based systems.

- Add patch "ACPI: Document how to refer to LEDs from remote nodes" to
  document using and referring to LEDs on ACPI.

- Rebase the set on AS3645A fixes I just sent ("AS3645A fixes")

- In v4l2_fwnode_reference_parse_sensor_common(), tell if parsing a
  property failed.

- Improved documentation for v4l2_async_notifier_parse_fwnode_endpoints().

- Fix v4l2_async_notifier_try_all_subdevs(); it is allowed that the list
  entry being iterated over is deleted but no other changes to the list
  are allowed. This could be the case if a sub-device driver's notifier
  binds a sub-device. Restart the loop whenever a match is found.

- Add patch "as3645a: Switch to fwnode property API" which also adds ACPI
  support.

since v7:

- Added three more patches:

	v4l: async: Remove re-probing support
	v4l: async: Use more intuitive names for internal functions
	dt: bindings: smiapp: Document lens-focus and flash properties

  The last one was already sent previously after the rest of the patchset.

- Removed re-probing support. This is hard to support and only useful in
  special cases. It can be reintroduced later on if there's really a need
  --- note that in e.g. omap3isp this was always broken and no-one ever
  complained.

- Remove smiapp driver's async complete callback (and ops). It is
  redundant: the sub-device nodes are created through the master notifier.

- Improve flash property documentation in video-interfaces.txt.

- Introduce helper functions to call notifier operations, one for each
  operation.

- Rename v4l2_async_test_notify as v4l2_async_match_notify and
  v4l2_async_belongs to v4l2_async_find_match.

- v4l2_async_notifier_test_all_subdevs() renamed as
  v4l2_async_notifier_try_all_subdevs().

- Made notifier_v4l2_dev a function (it was a macro).

- Registering subdev notifiers from sub-device drivers that control
  sub-devices created through sub-notifiers is now supported. In other
  words, subdev notifiers may be registered through other subdev
  notifiers. This is the source of the bulk of the changes between v7 and
  v8.

- Add explanatory comments to helper functions used by V4L2 async
  framework. This should help understanding the internal workings of the
  framework.

- Removed the "notifiers" list in struct v4l2_async_notifier. The
  information can be found from existing data structures.

- Explicitly check that registering a non-subdev notifier has v4l2_dev and
  a subdev notifier has a sub-device pointer.

- Unified several code paths between subdev notifiers and non-subdev
  notifiers.

- Fixed v4l2_async_notifier_release() --- calling it on a notifier for
  which the driver had allocated the subdevs array would lead calling
  kvfree() on that array. Now notifier->max_subdevs is checked before
  proceeding.

- Fixed a use-after-free issue in
  v4l2_async_notifier_fwnode_parse_endpoints().

- Small fixes to KernelDoc documentation for
  v4l2_async_notifier_parse_fwnode_endpoints().

since v6:

- Drop the last patch that added variant for parsing endpoints given
  specific port and endpoints numbers.

- Separate driver changes from the fwnode endpoint parser patch into two
  patches. rcar-vin driver is now using the name function.

- Use -ENOTCONN to tell the parser that and endpoint (or a reference) is
  to be ignored.

- parse_endpoint and parse_single callback functions are now optional and
  documented as such.

- Added Laurent's patch adding notifier operations struct which I rebase
  on the fwnode parser patchset. I wrote another patch to call the
  notifier operations through macros.

- Add DT bindings for flash and lens devices.

- V4L2 fwnode parser for references (such as flash and lens).

- Added smiapp driver support for async sub-devices (lens and flash).

- Added a few fixes for omap3isp.

since v5:

- Use v4l2_async_ prefix for static functions as well (4th patch)

- Use memcpy() to copy array rather than a loop

- Document that the v4l2_async_subdev pointer in driver specific struct
  must be the first member

- Improve documentation of the added functions (4th and 5th
  patches)

	- Arguments

	- More thorough explation of the purpose, usage and object
	  lifetime

- Added acks

since v4:

- Prepend the set with three documentation fixes.

- The driver's async struct must begin with struct v4l2_async_subdev. Fix this
  for omap3isp and document it.

- Improve documentation for new functions.

- Don't use devm_ family of functions for allocating memory. Introduce
  v4l2_async_notifier_release() to release memory resources.

- Rework both v4l2_async_notifier_fwnode_parse_endpoints() and
  v4l2_async_notifier_fwnode_parse_endpoint() and the local functions they
  call. This should make the code cleaner. Despite the name, for linking
  and typical usage reasons the functions remain in v4l2-fwnode.c.

- Convert rcar-vin to use v4l2_async_notifier_fwnode_parse_endpoint().

- Use kvmalloc() for allocating the notifier's subdevs array.

- max_subdevs argument for notifier_realloc is now the total maximum
  number of subdevs, not the number of available subdevs.

- Use fwnode_device_is_available() to make sure the device actually
  exists.

- Move the note telling v4l2_async_notifier_fwnode_parse_endpoints()
  should not be used by new drivers to the last patch adding
  v4l2_async_notifier_fwnode_parse_endpoint().

since v3:

- Rebase on current mediatree master.

since v2:

- Rebase on CCP2 support patches.

- Prepend a patch cleaning up omap3isp driver a little.

since v1:

- The first patch has been merged (it was a bugfix).

- In anticipation that the parsing can take place over several iterations,
  take the existing number of async sub-devices into account when
  re-allocating an array of async sub-devices.

- Rework the first patch to better anticipate parsing single endpoint at a
  time by a driver.

- Add a second patch that adds a function for parsing endpoints one at a
  time based on port and endpoint numbers.

Laurent Pinchart (1):
  v4l: async: Move async subdev notifier operations to a separate
    structure

Niklas Söderlund (1):
  v4l: async: fix unbind error in v4l2_async_notifier_unregister()

Sakari Ailus (30):
  v4l: async: Remove re-probing support
  v4l: async: Don't set sd->dev NULL in v4l2_async_cleanup
  v4l: async: Fix notifier complete callback error handling
  v4l: async: Correctly serialise async sub-device unregistration
  v4l: async: Use more intuitive names for internal functions
  v4l: async: Add V4L2 async documentation to the documentation build
  v4l: fwnode: Support generic parsing of graph endpoints in a device
  omap3isp: Use generic parser for parsing fwnode endpoints
  rcar-vin: Use generic parser for parsing fwnode endpoints
  omap3isp: Fix check for our own sub-devices
  omap3isp: Print the name of the entity where no source pads could be
    found
  v4l: async: Introduce helpers for calling async ops callbacks
  v4l: async: Register sub-devices before calling bound callback
  v4l: async: Allow async notifier register call succeed with no subdevs
  v4l: async: Prepare for async sub-device notifiers
  v4l: async: Allow binding notifiers to sub-devices
  v4l: async: Ensure only unique fwnodes are registered to notifiers
  dt: bindings: Add a binding for flash LED devices associated to a
    sensor
  dt: bindings: Add lens-focus binding for image sensors
  v4l: fwnode: Move KernelDoc documentation to the header
  v4l: fwnode: Add a helper function for parsing generic references
  v4l: fwnode: Add a helper function to obtain device / integer
    references
  v4l: fwnode: Add convenience function for parsing common external refs
  v4l: fwnode: Add a convenience function for registering sensors
  dt: bindings: smiapp: Document lens-focus and flash-leds properties
  smiapp: Add support for flash and lens devices
  et8ek8: Add support for flash and lens devices
  ov5670: Add support for flash and lens devices
  ov13858: Add support for flash and lens devices
  arm: dts: omap3: N9/N950: Add flash references to the camera

 .../devicetree/bindings/media/i2c/nokia,smia.txt   |   2 +
 .../devicetree/bindings/media/video-interfaces.txt |  10 +
 Documentation/media/kapi/v4l2-async.rst            |   3 +
 Documentation/media/kapi/v4l2-core.rst             |   1 +
 arch/arm/boot/dts/omap3-n9.dts                     |   1 +
 arch/arm/boot/dts/omap3-n950-n9.dtsi               |   4 +-
 arch/arm/boot/dts/omap3-n950.dts                   |   1 +
 drivers/media/i2c/et8ek8/et8ek8_driver.c           |   2 +-
 drivers/media/i2c/ov13858.c                        |   2 +-
 drivers/media/i2c/ov5670.c                         |   2 +-
 drivers/media/i2c/smiapp/smiapp-core.c             |   2 +-
 drivers/media/platform/am437x/am437x-vpfe.c        |   8 +-
 drivers/media/platform/atmel/atmel-isc.c           |  10 +-
 drivers/media/platform/atmel/atmel-isi.c           |  10 +-
 drivers/media/platform/davinci/vpif_capture.c      |   8 +-
 drivers/media/platform/davinci/vpif_display.c      |   8 +-
 drivers/media/platform/exynos4-is/media-dev.c      |   8 +-
 drivers/media/platform/omap3isp/isp.c              | 133 ++---
 drivers/media/platform/omap3isp/isp.h              |   5 +-
 drivers/media/platform/pxa_camera.c                |   8 +-
 drivers/media/platform/qcom/camss-8x16/camss.c     |   8 +-
 drivers/media/platform/rcar-vin/rcar-core.c        | 117 ++--
 drivers/media/platform/rcar-vin/rcar-dma.c         |  10 +-
 drivers/media/platform/rcar-vin/rcar-v4l2.c        |  14 +-
 drivers/media/platform/rcar-vin/rcar-vin.h         |   4 +-
 drivers/media/platform/rcar_drif.c                 |  10 +-
 drivers/media/platform/soc_camera/soc_camera.c     |  14 +-
 drivers/media/platform/stm32/stm32-dcmi.c          |  10 +-
 drivers/media/platform/ti-vpe/cal.c                |   8 +-
 drivers/media/platform/xilinx/xilinx-vipp.c        |   8 +-
 drivers/media/v4l2-core/v4l2-async.c               | 537 ++++++++++++++----
 drivers/media/v4l2-core/v4l2-fwnode.c              | 623 ++++++++++++++++++---
 drivers/staging/media/imx/imx-media-dev.c          |   8 +-
 include/media/v4l2-async.h                         |  90 ++-
 include/media/v4l2-fwnode.h                        | 220 +++++++-
 include/media/v4l2-subdev.h                        |   3 +
 36 files changed, 1488 insertions(+), 424 deletions(-)
 create mode 100644 Documentation/media/kapi/v4l2-async.rst

-- 
2.11.0

[PATCH v15 01/32] v4l: async: Remove re-probing support

[Sakari Ailus]

Remove V4L2 async re-probing support. The re-probing support has been
there to support cases where the sub-devices require resources provided by
the main driver's hardware to function, such as clocks.

Reprobing has allowed unbinding and again binding the main driver without
explicilty unbinding the sub-device drivers. This is certainly not a
common need, and the responsibility will be the user's going forward.

An alternative could have been to introduce notifier specific locks.
Considering the complexity of the re-probing and that it isn't really a
solution to a problem but a workaround, remove re-probing instead.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
 drivers/media/v4l2-core/v4l2-async.c | 54 +-----------------------------------
 1 file changed, 1 insertion(+), 53 deletions(-)

diff --git a/drivers/media/v4l2-core/v4l2-async.c b/drivers/media/v4l2-core/v4l2-async.c
index d741a8e0fdac..60a1a50b9537 100644
--- a/drivers/media/v4l2-core/v4l2-async.c
+++ b/drivers/media/v4l2-core/v4l2-async.c
@@ -198,78 +198,26 @@ EXPORT_SYMBOL(v4l2_async_notifier_register);
 void v4l2_async_notifier_unregister(struct v4l2_async_notifier *notifier)
 {
 	struct v4l2_subdev *sd, *tmp;
-	unsigned int notif_n_subdev = notifier->num_subdevs;
-	unsigned int n_subdev = min(notif_n_subdev, V4L2_MAX_SUBDEVS);
-	struct device **dev;
-	int i = 0;
 
 	if (!notifier->v4l2_dev)
 		return;
 
-	dev = kvmalloc_array(n_subdev, sizeof(*dev), GFP_KERNEL);
-	if (!dev) {
-		dev_err(notifier->v4l2_dev->dev,
-			"Failed to allocate device cache!\n");
-	}
-
 	mutex_lock(&list_lock);
 
 	list_del(&notifier->list);
 
 	list_for_each_entry_safe(sd, tmp, &notifier->done, async_list) {
-		struct device *d;
-
-		d = get_device(sd->dev);
-
 		v4l2_async_cleanup(sd);
 
-		/* If we handled USB devices, we'd have to lock the parent too */
-		device_release_driver(d);
-
 		if (notifier->unbind)
 			notifier->unbind(notifier, sd, sd->asd);
 
-		/*
-		 * Store device at the device cache, in order to call
-		 * put_device() on the final step
-		 */
-		if (dev)
-			dev[i++] = d;
-		else
-			put_device(d);
+		list_move(&sd->async_list, &subdev_list);
 	}
 
 	mutex_unlock(&list_lock);
 
-	/*
-	 * Call device_attach() to reprobe devices
-	 *
-	 * NOTE: If dev allocation fails, i is 0, and the whole loop won't be
-	 * executed.
-	 */
-	while (i--) {
-		struct device *d = dev[i];
-
-		if (d && device_attach(d) < 0) {
-			const char *name = "(none)";
-			int lock = device_trylock(d);
-
-			if (lock && d->driver)
-				name = d->driver->name;
-			dev_err(d, "Failed to re-probe to %s\n", name);
-			if (lock)
-				device_unlock(d);
-		}
-		put_device(d);
-	}
-	kvfree(dev);
-
 	notifier->v4l2_dev = NULL;
-
-	/*
-	 * Don't care about the waiting list, it is initialised and populated
-	 * upon notifier registration.
-	 */
 }
 EXPORT_SYMBOL(v4l2_async_notifier_unregister);
 
-- 
2.11.0

[PATCH v15 02/32] v4l: async: Don't set sd->dev NULL in v4l2_async_cleanup

[Sakari Ailus]

v4l2_async_cleanup() is called when the async sub-device is unbound from
the media device. As the pointer is set by the driver registering the
async sub-device, leave the pointer as set by the driver.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
---
 drivers/media/v4l2-core/v4l2-async.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/drivers/media/v4l2-core/v4l2-async.c b/drivers/media/v4l2-core/v4l2-async.c
index 60a1a50b9537..21c748bf3a7b 100644
--- a/drivers/media/v4l2-core/v4l2-async.c
+++ b/drivers/media/v4l2-core/v4l2-async.c
@@ -134,7 +134,6 @@ static void v4l2_async_cleanup(struct v4l2_subdev *sd)
 	/* Subdevice driver will reprobe and put the subdev back onto the list */
 	list_del_init(&sd->async_list);
 	sd->asd = NULL;
-	sd->dev = NULL;
 }
 
 int v4l2_async_notifier_register(struct v4l2_device *v4l2_dev,
-- 
2.11.0

[PATCH v15 03/32] v4l: async: fix unbind error in v4l2_async_notifier_unregister()

[Sakari Ailus]

From: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>

The call to v4l2_async_cleanup() will set sd->asd to NULL so passing it to
notifier->unbind() have no effect and leaves the notifier confused. Call
the unbind() callback prior to cleaning up the subdevice to avoid this.

Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
---
 drivers/media/v4l2-core/v4l2-async.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/media/v4l2-core/v4l2-async.c b/drivers/media/v4l2-core/v4l2-async.c
index 21c748bf3a7b..ca281438a0ae 100644
--- a/drivers/media/v4l2-core/v4l2-async.c
+++ b/drivers/media/v4l2-core/v4l2-async.c
@@ -206,11 +206,11 @@ void v4l2_async_notifier_unregister(struct v4l2_async_notifier *notifier)
 	list_del(&notifier->list);
 
 	list_for_each_entry_safe(sd, tmp, &notifier->done, async_list) {
-		v4l2_async_cleanup(sd);
-
 		if (notifier->unbind)
 			notifier->unbind(notifier, sd, sd->asd);
 
+		v4l2_async_cleanup(sd);
+
 		list_move(&sd->async_list, &subdev_list);
 	}
 
@@ -268,11 +268,11 @@ void v4l2_async_unregister_subdev(struct v4l2_subdev *sd)
 
 	list_add(&sd->asd->list, &notifier->waiting);
 
-	v4l2_async_cleanup(sd);
-
 	if (notifier->unbind)
 		notifier->unbind(notifier, sd, sd->asd);
 
+	v4l2_async_cleanup(sd);
+
 	mutex_unlock(&list_lock);
 }
 EXPORT_SYMBOL(v4l2_async_unregister_subdev);
-- 
2.11.0

[PATCH v15 04/32] v4l: async: Fix notifier complete callback error handling

[Sakari Ailus]

The notifier complete callback may return an error. This error code was
simply returned to the caller but never handled properly.

Move calling the complete callback function to the caller from
v4l2_async_test_notify and undo the work that was done either in async
sub-device or async notifier registration.

Reported-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
---
 drivers/media/v4l2-core/v4l2-async.c | 78 +++++++++++++++++++++++++++---------
 1 file changed, 60 insertions(+), 18 deletions(-)

diff --git a/drivers/media/v4l2-core/v4l2-async.c b/drivers/media/v4l2-core/v4l2-async.c
index ca281438a0ae..4924481451ca 100644
--- a/drivers/media/v4l2-core/v4l2-async.c
+++ b/drivers/media/v4l2-core/v4l2-async.c
@@ -122,9 +122,6 @@ static int v4l2_async_test_notify(struct v4l2_async_notifier *notifier,
 	/* Move from the global subdevice list to notifier's done */
 	list_move(&sd->async_list, &notifier->done);
 
-	if (list_empty(&notifier->waiting) && notifier->complete)
-		return notifier->complete(notifier);
-
 	return 0;
 }
 
@@ -136,11 +133,27 @@ static void v4l2_async_cleanup(struct v4l2_subdev *sd)
 	sd->asd = NULL;
 }
 
+static void v4l2_async_notifier_unbind_all_subdevs(
+	struct v4l2_async_notifier *notifier)
+{
+	struct v4l2_subdev *sd, *tmp;
+
+	list_for_each_entry_safe(sd, tmp, &notifier->done, async_list) {
+		if (notifier->unbind)
+			notifier->unbind(notifier, sd, sd->asd);
+
+		v4l2_async_cleanup(sd);
+
+		list_move(&sd->async_list, &subdev_list);
+	}
+}
+
 int v4l2_async_notifier_register(struct v4l2_device *v4l2_dev,
 				 struct v4l2_async_notifier *notifier)
 {
 	struct v4l2_subdev *sd, *tmp;
 	struct v4l2_async_subdev *asd;
+	int ret;
 	int i;
 
 	if (!v4l2_dev || !notifier->num_subdevs ||
@@ -185,19 +198,30 @@ int v4l2_async_notifier_register(struct v4l2_device *v4l2_dev,
 		}
 	}
 
+	if (list_empty(&notifier->waiting) && notifier->complete) {
+		ret = notifier->complete(notifier);
+		if (ret)
+			goto err_complete;
+	}
+
 	/* Keep also completed notifiers on the list */
 	list_add(&notifier->list, &notifier_list);
 
 	mutex_unlock(&list_lock);
 
 	return 0;
+
+err_complete:
+	v4l2_async_notifier_unbind_all_subdevs(notifier);
+
+	mutex_unlock(&list_lock);
+
+	return ret;
 }
 EXPORT_SYMBOL(v4l2_async_notifier_register);
 
 void v4l2_async_notifier_unregister(struct v4l2_async_notifier *notifier)
 {
-	struct v4l2_subdev *sd, *tmp;
-
 	if (!notifier->v4l2_dev)
 		return;
 
@@ -205,14 +229,7 @@ void v4l2_async_notifier_unregister(struct v4l2_async_notifier *notifier)
 
 	list_del(&notifier->list);
 
-	list_for_each_entry_safe(sd, tmp, &notifier->done, async_list) {
-		if (notifier->unbind)
-			notifier->unbind(notifier, sd, sd->asd);
-
-		v4l2_async_cleanup(sd);
-
-		list_move(&sd->async_list, &subdev_list);
-	}
+	v4l2_async_notifier_unbind_all_subdevs(notifier);
 
 	mutex_unlock(&list_lock);
 
@@ -223,6 +240,7 @@ EXPORT_SYMBOL(v4l2_async_notifier_unregister);
 int v4l2_async_register_subdev(struct v4l2_subdev *sd)
 {
 	struct v4l2_async_notifier *notifier;
+	int ret;
 
 	/*
 	 * No reference taken. The reference is held by the device
@@ -238,19 +256,43 @@ int v4l2_async_register_subdev(struct v4l2_subdev *sd)
 
 	list_for_each_entry(notifier, &notifier_list, list) {
 		struct v4l2_async_subdev *asd = v4l2_async_belongs(notifier, sd);
-		if (asd) {
-			int ret = v4l2_async_test_notify(notifier, sd, asd);
-			mutex_unlock(&list_lock);
-			return ret;
-		}
+		int ret;
+
+		if (!asd)
+			continue;
+
+		ret = v4l2_async_test_notify(notifier, sd, asd);
+		if (ret)
+			goto err_unlock;
+
+		if (!list_empty(&notifier->waiting) || !notifier->complete)
+			goto out_unlock;
+
+		ret = notifier->complete(notifier);
+		if (ret)
+			goto err_cleanup;
+
+		goto out_unlock;
 	}
 
 	/* None matched, wait for hot-plugging */
 	list_add(&sd->async_list, &subdev_list);
 
+out_unlock:
 	mutex_unlock(&list_lock);
 
 	return 0;
+
+err_cleanup:
+	if (notifier->unbind)
+		notifier->unbind(notifier, sd, sd->asd);
+
+	v4l2_async_cleanup(sd);
+
+err_unlock:
+	mutex_unlock(&list_lock);
+
+	return ret;
 }
 EXPORT_SYMBOL(v4l2_async_register_subdev);
 
-- 
2.11.0

[PATCH v15 05/32] v4l: async: Correctly serialise async sub-device unregistration

[Sakari Ailus]

The check whether an async sub-device is bound to a notifier was performed
without list_lock held, making it possible for another process to
unbind the async sub-device before the sub-device unregistration function
proceeds to take the lock.

Fix this by first acquiring the lock and then proceeding with the check.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
---
 drivers/media/v4l2-core/v4l2-async.c | 18 +++++++-----------
 1 file changed, 7 insertions(+), 11 deletions(-)

diff --git a/drivers/media/v4l2-core/v4l2-async.c b/drivers/media/v4l2-core/v4l2-async.c
index 4924481451ca..cde2cf2ab4b0 100644
--- a/drivers/media/v4l2-core/v4l2-async.c
+++ b/drivers/media/v4l2-core/v4l2-async.c
@@ -298,20 +298,16 @@ EXPORT_SYMBOL(v4l2_async_register_subdev);
 
 void v4l2_async_unregister_subdev(struct v4l2_subdev *sd)
 {
-	struct v4l2_async_notifier *notifier = sd->notifier;
-
-	if (!sd->asd) {
-		if (!list_empty(&sd->async_list))
-			v4l2_async_cleanup(sd);
-		return;
-	}
-
 	mutex_lock(&list_lock);
 
-	list_add(&sd->asd->list, &notifier->waiting);
+	if (sd->asd) {
+		struct v4l2_async_notifier *notifier = sd->notifier;
 
-	if (notifier->unbind)
-		notifier->unbind(notifier, sd, sd->asd);
+		list_add(&sd->asd->list, &notifier->waiting);
+
+		if (notifier->unbind)
+			notifier->unbind(notifier, sd, sd->asd);
+	}
 
 	v4l2_async_cleanup(sd);
 
-- 
2.11.0

[PATCH v15 06/32] v4l: async: Use more intuitive names for internal functions

[Sakari Ailus]

Rename internal functions to make the names of the functions better
describe what they do.

	Old name			New name
	v4l2_async_test_notify	v4l2_async_match_notify
	v4l2_async_belongs	v4l2_async_find_match

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
 drivers/media/v4l2-core/v4l2-async.c | 19 ++++++++++---------
 1 file changed, 10 insertions(+), 9 deletions(-)

diff --git a/drivers/media/v4l2-core/v4l2-async.c b/drivers/media/v4l2-core/v4l2-async.c
index cde2cf2ab4b0..8b84fea50c2a 100644
--- a/drivers/media/v4l2-core/v4l2-async.c
+++ b/drivers/media/v4l2-core/v4l2-async.c
@@ -60,8 +60,8 @@ static LIST_HEAD(subdev_list);
 static LIST_HEAD(notifier_list);
 static DEFINE_MUTEX(list_lock);
 
-static struct v4l2_async_subdev *v4l2_async_belongs(struct v4l2_async_notifier *notifier,
-						    struct v4l2_subdev *sd)
+static struct v4l2_async_subdev *v4l2_async_find_match(
+	struct v4l2_async_notifier *notifier, struct v4l2_subdev *sd)
 {
 	bool (*match)(struct v4l2_subdev *, struct v4l2_async_subdev *);
 	struct v4l2_async_subdev *asd;
@@ -95,9 +95,9 @@ static struct v4l2_async_subdev *v4l2_async_belongs(struct v4l2_async_notifier *
 	return NULL;
 }
 
-static int v4l2_async_test_notify(struct v4l2_async_notifier *notifier,
-				  struct v4l2_subdev *sd,
-				  struct v4l2_async_subdev *asd)
+static int v4l2_async_match_notify(struct v4l2_async_notifier *notifier,
+				   struct v4l2_subdev *sd,
+				   struct v4l2_async_subdev *asd)
 {
 	int ret;
 
@@ -187,11 +187,11 @@ int v4l2_async_notifier_register(struct v4l2_device *v4l2_dev,
 	list_for_each_entry_safe(sd, tmp, &subdev_list, async_list) {
 		int ret;
 
-		asd = v4l2_async_belongs(notifier, sd);
+		asd = v4l2_async_find_match(notifier, sd);
 		if (!asd)
 			continue;
 
-		ret = v4l2_async_test_notify(notifier, sd, asd);
+		ret = v4l2_async_match_notify(notifier, sd, asd);
 		if (ret < 0) {
 			mutex_unlock(&list_lock);
 			return ret;
@@ -255,13 +255,14 @@ int v4l2_async_register_subdev(struct v4l2_subdev *sd)
 	INIT_LIST_HEAD(&sd->async_list);
 
 	list_for_each_entry(notifier, &notifier_list, list) {
-		struct v4l2_async_subdev *asd = v4l2_async_belongs(notifier, sd);
+		struct v4l2_async_subdev *asd = v4l2_async_find_match(notifier,
+								      sd);
 		int ret;
 
 		if (!asd)
 			continue;
 
-		ret = v4l2_async_test_notify(notifier, sd, asd);
+		ret = v4l2_async_match_notify(notifier, sd, asd);
 		if (ret)
 			goto err_unlock;
 
-- 
2.11.0

[PATCH v15 07/32] v4l: async: Add V4L2 async documentation to the documentation build

[Sakari Ailus]

The V4L2 async wasn't part of the documentation build. Fix this.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
 Documentation/media/kapi/v4l2-async.rst | 3 +++
 Documentation/media/kapi/v4l2-core.rst  | 1 +
 2 files changed, 4 insertions(+)
 create mode 100644 Documentation/media/kapi/v4l2-async.rst

diff --git a/Documentation/media/kapi/v4l2-async.rst b/Documentation/media/kapi/v4l2-async.rst
new file mode 100644
index 000000000000..523ff9eb09a0
--- /dev/null
+++ b/Documentation/media/kapi/v4l2-async.rst
@@ -0,0 +1,3 @@
+V4L2 async kAPI
+^^^^^^^^^^^^^^^
+.. kernel-doc:: include/media/v4l2-async.h
diff --git a/Documentation/media/kapi/v4l2-core.rst b/Documentation/media/kapi/v4l2-core.rst
index c7434f38fd9c..5cf292037a48 100644
--- a/Documentation/media/kapi/v4l2-core.rst
+++ b/Documentation/media/kapi/v4l2-core.rst
@@ -19,6 +19,7 @@ Video4Linux devices
     v4l2-mc
     v4l2-mediabus
     v4l2-mem2mem
+    v4l2-async
     v4l2-fwnode
     v4l2-rect
     v4l2-tuner
-- 
2.11.0

[PATCH v15 08/32] v4l: fwnode: Support generic parsing of graph endpoints in a device

[Sakari Ailus]

Add two functions for parsing devices graph endpoints:
v4l2_async_notifier_parse_fwnode_endpoints and
v4l2_async_notifier_parse_fwnode_endpoints_by_port. The former iterates
over all endpoints whereas the latter only iterates over the endpoints in
a given port.

The former is mostly useful for existing drivers that currently implement
the iteration over all the endpoints themselves whereas the latter is
especially intended for devices with both sinks and sources: async
sub-devices for external devices connected to the device's sources will
have already been set up, or the external sub-devices are part of the
master device.

Depends-on: ("device property: preserve usecount for node passed to of_fwnode_graph_get_port_parent()")
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
---
 drivers/media/v4l2-core/v4l2-async.c  |  31 ++++++
 drivers/media/v4l2-core/v4l2-fwnode.c | 196 ++++++++++++++++++++++++++++++++++
 include/media/v4l2-async.h            |  24 ++++-
 include/media/v4l2-fwnode.h           | 118 ++++++++++++++++++++
 4 files changed, 367 insertions(+), 2 deletions(-)

diff --git a/drivers/media/v4l2-core/v4l2-async.c b/drivers/media/v4l2-core/v4l2-async.c
index 8b84fea50c2a..46aebfc75e43 100644
--- a/drivers/media/v4l2-core/v4l2-async.c
+++ b/drivers/media/v4l2-core/v4l2-async.c
@@ -22,6 +22,7 @@
 
 #include <media/v4l2-async.h>
 #include <media/v4l2-device.h>
+#include <media/v4l2-fwnode.h>
 #include <media/v4l2-subdev.h>
 
 static bool match_i2c(struct v4l2_subdev *sd, struct v4l2_async_subdev *asd)
@@ -237,6 +238,36 @@ void v4l2_async_notifier_unregister(struct v4l2_async_notifier *notifier)
 }
 EXPORT_SYMBOL(v4l2_async_notifier_unregister);
 
+void v4l2_async_notifier_cleanup(struct v4l2_async_notifier *notifier)
+{
+	unsigned int i;
+
+	if (!notifier->max_subdevs)
+		return;
+
+	for (i = 0; i < notifier->num_subdevs; i++) {
+		struct v4l2_async_subdev *asd = notifier->subdevs[i];
+
+		switch (asd->match_type) {
+		case V4L2_ASYNC_MATCH_FWNODE:
+			fwnode_handle_put(asd->match.fwnode.fwnode);
+			break;
+		default:
+			WARN_ON_ONCE(true);
+			break;
+		}
+
+		kfree(asd);
+	}
+
+	notifier->max_subdevs = 0;
+	notifier->num_subdevs = 0;
+
+	kvfree(notifier->subdevs);
+	notifier->subdevs = NULL;
+}
+EXPORT_SYMBOL_GPL(v4l2_async_notifier_cleanup);
+
 int v4l2_async_register_subdev(struct v4l2_subdev *sd)
 {
 	struct v4l2_async_notifier *notifier;
diff --git a/drivers/media/v4l2-core/v4l2-fwnode.c b/drivers/media/v4l2-core/v4l2-fwnode.c
index 40b2fbfe8865..df0695b7bbcc 100644
--- a/drivers/media/v4l2-core/v4l2-fwnode.c
+++ b/drivers/media/v4l2-core/v4l2-fwnode.c
@@ -19,6 +19,7 @@
  */
 #include <linux/acpi.h>
 #include <linux/kernel.h>
+#include <linux/mm.h>
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/property.h>
@@ -26,6 +27,7 @@
 #include <linux/string.h>
 #include <linux/types.h>
 
+#include <media/v4l2-async.h>
 #include <media/v4l2-fwnode.h>
 
 enum v4l2_fwnode_bus_type {
@@ -388,6 +390,200 @@ void v4l2_fwnode_put_link(struct v4l2_fwnode_link *link)
 }
 EXPORT_SYMBOL_GPL(v4l2_fwnode_put_link);
 
+static int v4l2_async_notifier_realloc(struct v4l2_async_notifier *notifier,
+				       unsigned int max_subdevs)
+{
+	struct v4l2_async_subdev **subdevs;
+
+	if (max_subdevs <= notifier->max_subdevs)
+		return 0;
+
+	subdevs = kvmalloc_array(
+		max_subdevs, sizeof(*notifier->subdevs),
+		GFP_KERNEL | __GFP_ZERO);
+	if (!subdevs)
+		return -ENOMEM;
+
+	if (notifier->subdevs) {
+		memcpy(subdevs, notifier->subdevs,
+		       sizeof(*subdevs) * notifier->num_subdevs);
+
+		kvfree(notifier->subdevs);
+	}
+
+	notifier->subdevs = subdevs;
+	notifier->max_subdevs = max_subdevs;
+
+	return 0;
+}
+
+static int v4l2_async_notifier_fwnode_parse_endpoint(
+	struct device *dev, struct v4l2_async_notifier *notifier,
+	struct fwnode_handle *endpoint, unsigned int asd_struct_size,
+	int (*parse_endpoint)(struct device *dev,
+			    struct v4l2_fwnode_endpoint *vep,
+			    struct v4l2_async_subdev *asd))
+{
+	struct v4l2_async_subdev *asd;
+	struct v4l2_fwnode_endpoint *vep;
+	int ret = 0;
+
+	asd = kzalloc(asd_struct_size, GFP_KERNEL);
+	if (!asd)
+		return -ENOMEM;
+
+	asd->match_type = V4L2_ASYNC_MATCH_FWNODE;
+	asd->match.fwnode.fwnode =
+		fwnode_graph_get_remote_port_parent(endpoint);
+	if (!asd->match.fwnode.fwnode) {
+		dev_warn(dev, "bad remote port parent\n");
+		ret = -EINVAL;
+		goto out_err;
+	}
+
+	vep = v4l2_fwnode_endpoint_alloc_parse(endpoint);
+	if (IS_ERR(vep)) {
+		ret = PTR_ERR(vep);
+		dev_warn(dev, "unable to parse V4L2 fwnode endpoint (%d)\n",
+			 ret);
+		goto out_err;
+	}
+
+	ret = parse_endpoint ? parse_endpoint(dev, vep, asd) : 0;
+	if (ret == -ENOTCONN)
+		dev_dbg(dev, "ignoring port@%u/endpoint@%u\n", vep->base.port,
+			vep->base.id);
+	else if (ret < 0)
+		dev_warn(dev,
+			 "driver could not parse port@%u/endpoint@%u (%d)\n",
+			 vep->base.port, vep->base.id, ret);
+	v4l2_fwnode_endpoint_free(vep);
+	if (ret < 0)
+		goto out_err;
+
+	notifier->subdevs[notifier->num_subdevs] = asd;
+	notifier->num_subdevs++;
+
+	return 0;
+
+out_err:
+	fwnode_handle_put(asd->match.fwnode.fwnode);
+	kfree(asd);
+
+	return ret == -ENOTCONN ? 0 : ret;
+}
+
+static int __v4l2_async_notifier_parse_fwnode_endpoints(
+	struct device *dev, struct v4l2_async_notifier *notifier,
+	size_t asd_struct_size, unsigned int port, bool has_port,
+	int (*parse_endpoint)(struct device *dev,
+			    struct v4l2_fwnode_endpoint *vep,
+			    struct v4l2_async_subdev *asd))
+{
+	struct fwnode_handle *fwnode;
+	unsigned int max_subdevs = notifier->max_subdevs;
+	int ret;
+
+	if (WARN_ON(asd_struct_size < sizeof(struct v4l2_async_subdev)))
+		return -EINVAL;
+
+	for (fwnode = NULL; (fwnode = fwnode_graph_get_next_endpoint(
+				     dev_fwnode(dev), fwnode)); ) {
+		struct fwnode_handle *dev_fwnode;
+		bool is_available;
+
+		dev_fwnode = fwnode_graph_get_port_parent(fwnode);
+		is_available = fwnode_device_is_available(dev_fwnode);
+		fwnode_handle_put(dev_fwnode);
+		if (!is_available)
+			continue;
+
+		if (has_port) {
+			struct fwnode_endpoint ep;
+
+			ret = fwnode_graph_parse_endpoint(fwnode, &ep);
+			if (ret) {
+				fwnode_handle_put(fwnode);
+				return ret;
+			}
+
+			if (ep.port != port)
+				continue;
+		}
+		max_subdevs++;
+	}
+
+	/* No subdevs to add? Return here. */
+	if (max_subdevs == notifier->max_subdevs)
+		return 0;
+
+	ret = v4l2_async_notifier_realloc(notifier, max_subdevs);
+	if (ret)
+		return ret;
+
+	for (fwnode = NULL; (fwnode = fwnode_graph_get_next_endpoint(
+				     dev_fwnode(dev), fwnode)); ) {
+		struct fwnode_handle *dev_fwnode;
+		bool is_available;
+
+		dev_fwnode = fwnode_graph_get_port_parent(fwnode);
+		is_available = fwnode_device_is_available(dev_fwnode);
+		fwnode_handle_put(dev_fwnode);
+
+		if (!fwnode_device_is_available(dev_fwnode))
+			continue;
+
+		if (WARN_ON(notifier->num_subdevs >= notifier->max_subdevs)) {
+			ret = -EINVAL;
+			break;
+		}
+
+		if (has_port) {
+			struct fwnode_endpoint ep;
+
+			ret = fwnode_graph_parse_endpoint(fwnode, &ep);
+			if (ret)
+				break;
+
+			if (ep.port != port)
+				continue;
+		}
+
+		ret = v4l2_async_notifier_fwnode_parse_endpoint(
+			dev, notifier, fwnode, asd_struct_size, parse_endpoint);
+		if (ret < 0)
+			break;
+	}
+
+	fwnode_handle_put(fwnode);
+
+	return ret;
+}
+
+int v4l2_async_notifier_parse_fwnode_endpoints(
+	struct device *dev, struct v4l2_async_notifier *notifier,
+	size_t asd_struct_size,
+	int (*parse_endpoint)(struct device *dev,
+			    struct v4l2_fwnode_endpoint *vep,
+			    struct v4l2_async_subdev *asd))
+{
+	return __v4l2_async_notifier_parse_fwnode_endpoints(
+		dev, notifier, asd_struct_size, 0, false, parse_endpoint);
+}
+EXPORT_SYMBOL_GPL(v4l2_async_notifier_parse_fwnode_endpoints);
+
+int v4l2_async_notifier_parse_fwnode_endpoints_by_port(
+	struct device *dev, struct v4l2_async_notifier *notifier,
+	size_t asd_struct_size, unsigned int port,
+	int (*parse_endpoint)(struct device *dev,
+			    struct v4l2_fwnode_endpoint *vep,
+			    struct v4l2_async_subdev *asd))
+{
+	return __v4l2_async_notifier_parse_fwnode_endpoints(
+		dev, notifier, asd_struct_size, port, true, parse_endpoint);
+}
+EXPORT_SYMBOL_GPL(v4l2_async_notifier_parse_fwnode_endpoints_by_port);
+
 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Sakari Ailus <sakari.ailus@linux.intel.com>");
 MODULE_AUTHOR("Sylwester Nawrocki <s.nawrocki@samsung.com>");
diff --git a/include/media/v4l2-async.h b/include/media/v4l2-async.h
index c69d8c8a66d0..329aeebd1a80 100644
--- a/include/media/v4l2-async.h
+++ b/include/media/v4l2-async.h
@@ -18,7 +18,6 @@ struct device;
 struct device_node;
 struct v4l2_device;
 struct v4l2_subdev;
-struct v4l2_async_notifier;
 
 /* A random max subdevice number, used to allocate an array on stack */
 #define V4L2_MAX_SUBDEVS 128U
@@ -50,6 +49,10 @@ enum v4l2_async_match_type {
  * @match:	union of per-bus type matching data sets
  * @list:	used to link struct v4l2_async_subdev objects, waiting to be
  *		probed, to a notifier->waiting list
+ *
+ * When this struct is used as a member in a driver specific struct,
+ * the driver specific struct shall contain the &struct
+ * v4l2_async_subdev as its first member.
  */
 struct v4l2_async_subdev {
 	enum v4l2_async_match_type match_type;
@@ -78,7 +81,8 @@ struct v4l2_async_subdev {
 /**
  * struct v4l2_async_notifier - v4l2_device notifier data
  *
- * @num_subdevs: number of subdevices
+ * @num_subdevs: number of subdevices used in the subdevs array
+ * @max_subdevs: number of subdevices allocated in the subdevs array
  * @subdevs:	array of pointers to subdevice descriptors
  * @v4l2_dev:	pointer to struct v4l2_device
  * @waiting:	list of struct v4l2_async_subdev, waiting for their drivers
@@ -90,6 +94,7 @@ struct v4l2_async_subdev {
  */
 struct v4l2_async_notifier {
 	unsigned int num_subdevs;
+	unsigned int max_subdevs;
 	struct v4l2_async_subdev **subdevs;
 	struct v4l2_device *v4l2_dev;
 	struct list_head waiting;
@@ -121,6 +126,21 @@ int v4l2_async_notifier_register(struct v4l2_device *v4l2_dev,
 void v4l2_async_notifier_unregister(struct v4l2_async_notifier *notifier);
 
 /**
+ * v4l2_async_notifier_cleanup - clean up notifier resources
+ * @notifier: the notifier the resources of which are to be cleaned up
+ *
+ * Release memory resources related to a notifier, including the async
+ * sub-devices allocated for the purposes of the notifier but not the notifier
+ * itself. The user is responsible for calling this function to clean up the
+ * notifier after calling @v4l2_async_notifier_parse_fwnode_endpoints.
+ *
+ * There is no harm from calling v4l2_async_notifier_cleanup in other
+ * cases as long as its memory has been zeroed after it has been
+ * allocated.
+ */
+void v4l2_async_notifier_cleanup(struct v4l2_async_notifier *notifier);
+
+/**
  * v4l2_async_register_subdev - registers a sub-device to the asynchronous
  * 	subdevice framework
  *
diff --git a/include/media/v4l2-fwnode.h b/include/media/v4l2-fwnode.h
index 7adec9851d9e..ac605af9b877 100644
--- a/include/media/v4l2-fwnode.h
+++ b/include/media/v4l2-fwnode.h
@@ -25,6 +25,8 @@
 #include <media/v4l2-mediabus.h>
 
 struct fwnode_handle;
+struct v4l2_async_notifier;
+struct v4l2_async_subdev;
 
 #define V4L2_FWNODE_CSI2_MAX_DATA_LANES	4
 
@@ -122,4 +124,120 @@ int v4l2_fwnode_parse_link(struct fwnode_handle *fwnode,
 			   struct v4l2_fwnode_link *link);
 void v4l2_fwnode_put_link(struct v4l2_fwnode_link *link);
 
+/**
+ * v4l2_async_notifier_parse_fwnode_endpoints - Parse V4L2 fwnode endpoints in a
+ *						device node
+ * @dev: the device the endpoints of which are to be parsed
+ * @notifier: notifier for @dev
+ * @asd_struct_size: size of the driver's async sub-device struct, including
+ *		     sizeof(struct v4l2_async_subdev). The &struct
+ *		     v4l2_async_subdev shall be the first member of
+ *		     the driver's async sub-device struct, i.e. both
+ *		     begin at the same memory address.
+ * @parse_endpoint: Driver's callback function called on each V4L2 fwnode
+ *		    endpoint. Optional.
+ *		    Return: %0 on success
+ *			    %-ENOTCONN if the endpoint is to be skipped but this
+ *				       should not be considered as an error
+ *			    %-EINVAL if the endpoint configuration is invalid
+ *
+ * Parse the fwnode endpoints of the @dev device and populate the async sub-
+ * devices array of the notifier. The @parse_endpoint callback function is
+ * called for each endpoint with the corresponding async sub-device pointer to
+ * let the caller initialize the driver-specific part of the async sub-device
+ * structure.
+ *
+ * The notifier memory shall be zeroed before this function is called on the
+ * notifier.
+ *
+ * This function may not be called on a registered notifier and may be called on
+ * a notifier only once.
+ *
+ * Do not change the notifier's subdevs array, take references to the subdevs
+ * array itself or change the notifier's num_subdevs field. This is because this
+ * function allocates and reallocates the subdevs array based on parsing
+ * endpoints.
+ *
+ * The &struct v4l2_fwnode_endpoint passed to the callback function
+ * @parse_endpoint is released once the function is finished. If there is a need
+ * to retain that configuration, the user needs to allocate memory for it.
+ *
+ * Any notifier populated using this function must be released with a call to
+ * v4l2_async_notifier_cleanup() after it has been unregistered and the async
+ * sub-devices are no longer in use, even if the function returned an error.
+ *
+ * Return: %0 on success, including when no async sub-devices are found
+ *	   %-ENOMEM if memory allocation failed
+ *	   %-EINVAL if graph or endpoint parsing failed
+ *	   Other error codes as returned by @parse_endpoint
+ */
+int v4l2_async_notifier_parse_fwnode_endpoints(
+	struct device *dev, struct v4l2_async_notifier *notifier,
+	size_t asd_struct_size,
+	int (*parse_endpoint)(struct device *dev,
+			      struct v4l2_fwnode_endpoint *vep,
+			      struct v4l2_async_subdev *asd));
+
+/**
+ * v4l2_async_notifier_parse_fwnode_endpoints_by_port - Parse V4L2 fwnode
+ *							endpoints of a port in a
+ *							device node
+ * @dev: the device the endpoints of which are to be parsed
+ * @notifier: notifier for @dev
+ * @asd_struct_size: size of the driver's async sub-device struct, including
+ *		     sizeof(struct v4l2_async_subdev). The &struct
+ *		     v4l2_async_subdev shall be the first member of
+ *		     the driver's async sub-device struct, i.e. both
+ *		     begin at the same memory address.
+ * @port: port number where endpoints are to be parsed
+ * @parse_endpoint: Driver's callback function called on each V4L2 fwnode
+ *		    endpoint. Optional.
+ *		    Return: %0 on success
+ *			    %-ENOTCONN if the endpoint is to be skipped but this
+ *				       should not be considered as an error
+ *			    %-EINVAL if the endpoint configuration is invalid
+ *
+ * This function is just like v4l2_async_notifier_parse_fwnode_endpoints() with
+ * the exception that it only parses endpoints in a given port. This is useful
+ * on devices that have both sinks and sources: the async sub-devices connected
+ * to sources have already been configured by another driver (on capture
+ * devices). In this case the driver must know which ports to parse.
+ *
+ * Parse the fwnode endpoints of the @dev device on a given @port and populate
+ * the async sub-devices array of the notifier. The @parse_endpoint callback
+ * function is called for each endpoint with the corresponding async sub-device
+ * pointer to let the caller initialize the driver-specific part of the async
+ * sub-device structure.
+ *
+ * The notifier memory shall be zeroed before this function is called on the
+ * notifier the first time.
+ *
+ * This function may not be called on a registered notifier and may be called on
+ * a notifier only once per port.
+ *
+ * Do not change the notifier's subdevs array, take references to the subdevs
+ * array itself or change the notifier's num_subdevs field. This is because this
+ * function allocates and reallocates the subdevs array based on parsing
+ * endpoints.
+ *
+ * The &struct v4l2_fwnode_endpoint passed to the callback function
+ * @parse_endpoint is released once the function is finished. If there is a need
+ * to retain that configuration, the user needs to allocate memory for it.
+ *
+ * Any notifier populated using this function must be released with a call to
+ * v4l2_async_notifier_cleanup() after it has been unregistered and the async
+ * sub-devices are no longer in use, even if the function returned an error.
+ *
+ * Return: %0 on success, including when no async sub-devices are found
+ *	   %-ENOMEM if memory allocation failed
+ *	   %-EINVAL if graph or endpoint parsing failed
+ *	   Other error codes as returned by @parse_endpoint
+ */
+int v4l2_async_notifier_parse_fwnode_endpoints_by_port(
+	struct device *dev, struct v4l2_async_notifier *notifier,
+	size_t asd_struct_size, unsigned int port,
+	int (*parse_endpoint)(struct device *dev,
+			      struct v4l2_fwnode_endpoint *vep,
+			      struct v4l2_async_subdev *asd));
+
 #endif /* _V4L2_FWNODE_H */
-- 
2.11.0

[PATCH v15 09/32] omap3isp: Use generic parser for parsing fwnode endpoints

[Sakari Ailus]

Instead of using a custom driver implementation, use
v4l2_async_notifier_parse_fwnode_endpoints() to parse the fwnode endpoints
of the device.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
 drivers/media/platform/omap3isp/isp.c | 121 +++++++++++-----------------------
 drivers/media/platform/omap3isp/isp.h |   5 +-
 2 files changed, 40 insertions(+), 86 deletions(-)

diff --git a/drivers/media/platform/omap3isp/isp.c b/drivers/media/platform/omap3isp/isp.c
index 1a428fe9f070..97a5206b6ddc 100644
--- a/drivers/media/platform/omap3isp/isp.c
+++ b/drivers/media/platform/omap3isp/isp.c
@@ -2001,6 +2001,7 @@ static int isp_remove(struct platform_device *pdev)
 	__omap3isp_put(isp, false);
 
 	media_entity_enum_cleanup(&isp->crashed);
+	v4l2_async_notifier_cleanup(&isp->notifier);
 
 	return 0;
 }
@@ -2011,44 +2012,41 @@ enum isp_of_phy {
 	ISP_OF_PHY_CSIPHY2,
 };
 
-static int isp_fwnode_parse(struct device *dev, struct fwnode_handle *fwnode,
-			    struct isp_async_subdev *isd)
+static int isp_fwnode_parse(struct device *dev,
+			    struct v4l2_fwnode_endpoint *vep,
+			    struct v4l2_async_subdev *asd)
 {
+	struct isp_async_subdev *isd =
+		container_of(asd, struct isp_async_subdev, asd);
 	struct isp_bus_cfg *buscfg = &isd->bus;
-	struct v4l2_fwnode_endpoint vep;
-	unsigned int i;
-	int ret;
 	bool csi1 = false;
-
-	ret = v4l2_fwnode_endpoint_parse(fwnode, &vep);
-	if (ret)
-		return ret;
+	unsigned int i;
 
 	dev_dbg(dev, "parsing endpoint %pOF, interface %u\n",
-		to_of_node(fwnode), vep.base.port);
+		to_of_node(vep->base.local_fwnode), vep->base.port);
 
-	switch (vep.base.port) {
+	switch (vep->base.port) {
 	case ISP_OF_PHY_PARALLEL:
 		buscfg->interface = ISP_INTERFACE_PARALLEL;
 		buscfg->bus.parallel.data_lane_shift =
-			vep.bus.parallel.data_shift;
+			vep->bus.parallel.data_shift;
 		buscfg->bus.parallel.clk_pol =
-			!!(vep.bus.parallel.flags
+			!!(vep->bus.parallel.flags
 			   & V4L2_MBUS_PCLK_SAMPLE_FALLING);
 		buscfg->bus.parallel.hs_pol =
-			!!(vep.bus.parallel.flags & V4L2_MBUS_VSYNC_ACTIVE_LOW);
+			!!(vep->bus.parallel.flags & V4L2_MBUS_VSYNC_ACTIVE_LOW);
 		buscfg->bus.parallel.vs_pol =
-			!!(vep.bus.parallel.flags & V4L2_MBUS_HSYNC_ACTIVE_LOW);
+			!!(vep->bus.parallel.flags & V4L2_MBUS_HSYNC_ACTIVE_LOW);
 		buscfg->bus.parallel.fld_pol =
-			!!(vep.bus.parallel.flags & V4L2_MBUS_FIELD_EVEN_LOW);
+			!!(vep->bus.parallel.flags & V4L2_MBUS_FIELD_EVEN_LOW);
 		buscfg->bus.parallel.data_pol =
-			!!(vep.bus.parallel.flags & V4L2_MBUS_DATA_ACTIVE_LOW);
-		buscfg->bus.parallel.bt656 = vep.bus_type == V4L2_MBUS_BT656;
+			!!(vep->bus.parallel.flags & V4L2_MBUS_DATA_ACTIVE_LOW);
+		buscfg->bus.parallel.bt656 = vep->bus_type == V4L2_MBUS_BT656;
 		break;
 
 	case ISP_OF_PHY_CSIPHY1:
 	case ISP_OF_PHY_CSIPHY2:
-		switch (vep.bus_type) {
+		switch (vep->bus_type) {
 		case V4L2_MBUS_CCP2:
 		case V4L2_MBUS_CSI1:
 			dev_dbg(dev, "CSI-1/CCP-2 configuration\n");
@@ -2060,11 +2058,11 @@ static int isp_fwnode_parse(struct device *dev, struct fwnode_handle *fwnode,
 			break;
 		default:
 			dev_err(dev, "unsupported bus type %u\n",
-				vep.bus_type);
+				vep->bus_type);
 			return -EINVAL;
 		}
 
-		switch (vep.base.port) {
+		switch (vep->base.port) {
 		case ISP_OF_PHY_CSIPHY1:
 			if (csi1)
 				buscfg->interface = ISP_INTERFACE_CCP2B_PHY1;
@@ -2080,47 +2078,47 @@ static int isp_fwnode_parse(struct device *dev, struct fwnode_handle *fwnode,
 		}
 		if (csi1) {
 			buscfg->bus.ccp2.lanecfg.clk.pos =
-				vep.bus.mipi_csi1.clock_lane;
+				vep->bus.mipi_csi1.clock_lane;
 			buscfg->bus.ccp2.lanecfg.clk.pol =
-				vep.bus.mipi_csi1.lane_polarity[0];
+				vep->bus.mipi_csi1.lane_polarity[0];
 			dev_dbg(dev, "clock lane polarity %u, pos %u\n",
 				buscfg->bus.ccp2.lanecfg.clk.pol,
 				buscfg->bus.ccp2.lanecfg.clk.pos);
 
 			buscfg->bus.ccp2.lanecfg.data[0].pos =
-				vep.bus.mipi_csi1.data_lane;
+				vep->bus.mipi_csi1.data_lane;
 			buscfg->bus.ccp2.lanecfg.data[0].pol =
-				vep.bus.mipi_csi1.lane_polarity[1];
+				vep->bus.mipi_csi1.lane_polarity[1];
 
 			dev_dbg(dev, "data lane polarity %u, pos %u\n",
 				buscfg->bus.ccp2.lanecfg.data[0].pol,
 				buscfg->bus.ccp2.lanecfg.data[0].pos);
 
 			buscfg->bus.ccp2.strobe_clk_pol =
-				vep.bus.mipi_csi1.clock_inv;
-			buscfg->bus.ccp2.phy_layer = vep.bus.mipi_csi1.strobe;
+				vep->bus.mipi_csi1.clock_inv;
+			buscfg->bus.ccp2.phy_layer = vep->bus.mipi_csi1.strobe;
 			buscfg->bus.ccp2.ccp2_mode =
-				vep.bus_type == V4L2_MBUS_CCP2;
+				vep->bus_type == V4L2_MBUS_CCP2;
 			buscfg->bus.ccp2.vp_clk_pol = 1;
 
 			buscfg->bus.ccp2.crc = 1;
 		} else {
 			buscfg->bus.csi2.lanecfg.clk.pos =
-				vep.bus.mipi_csi2.clock_lane;
+				vep->bus.mipi_csi2.clock_lane;
 			buscfg->bus.csi2.lanecfg.clk.pol =
-				vep.bus.mipi_csi2.lane_polarities[0];
+				vep->bus.mipi_csi2.lane_polarities[0];
 			dev_dbg(dev, "clock lane polarity %u, pos %u\n",
 				buscfg->bus.csi2.lanecfg.clk.pol,
 				buscfg->bus.csi2.lanecfg.clk.pos);
 
 			buscfg->bus.csi2.num_data_lanes =
-				vep.bus.mipi_csi2.num_data_lanes;
+				vep->bus.mipi_csi2.num_data_lanes;
 
 			for (i = 0; i < buscfg->bus.csi2.num_data_lanes; i++) {
 				buscfg->bus.csi2.lanecfg.data[i].pos =
-					vep.bus.mipi_csi2.data_lanes[i];
+					vep->bus.mipi_csi2.data_lanes[i];
 				buscfg->bus.csi2.lanecfg.data[i].pol =
-					vep.bus.mipi_csi2.lane_polarities[i + 1];
+					vep->bus.mipi_csi2.lane_polarities[i + 1];
 				dev_dbg(dev,
 					"data lane %u polarity %u, pos %u\n", i,
 					buscfg->bus.csi2.lanecfg.data[i].pol,
@@ -2137,57 +2135,13 @@ static int isp_fwnode_parse(struct device *dev, struct fwnode_handle *fwnode,
 
 	default:
 		dev_warn(dev, "%pOF: invalid interface %u\n",
-			 to_of_node(fwnode), vep.base.port);
+			 to_of_node(vep->base.local_fwnode), vep->base.port);
 		return -EINVAL;
 	}
 
 	return 0;
 }
 
-static int isp_fwnodes_parse(struct device *dev,
-			     struct v4l2_async_notifier *notifier)
-{
-	struct fwnode_handle *fwnode = NULL;
-
-	notifier->subdevs = devm_kcalloc(
-		dev, ISP_MAX_SUBDEVS, sizeof(*notifier->subdevs), GFP_KERNEL);
-	if (!notifier->subdevs)
-		return -ENOMEM;
-
-	while (notifier->num_subdevs < ISP_MAX_SUBDEVS &&
-	       (fwnode = fwnode_graph_get_next_endpoint(
-			of_fwnode_handle(dev->of_node), fwnode))) {
-		struct isp_async_subdev *isd;
-
-		isd = devm_kzalloc(dev, sizeof(*isd), GFP_KERNEL);
-		if (!isd)
-			goto error;
-
-		if (isp_fwnode_parse(dev, fwnode, isd)) {
-			devm_kfree(dev, isd);
-			continue;
-		}
-
-		notifier->subdevs[notifier->num_subdevs] = &isd->asd;
-
-		isd->asd.match.fwnode.fwnode =
-			fwnode_graph_get_remote_port_parent(fwnode);
-		if (!isd->asd.match.fwnode.fwnode) {
-			dev_warn(dev, "bad remote port parent\n");
-			goto error;
-		}
-
-		isd->asd.match_type = V4L2_ASYNC_MATCH_FWNODE;
-		notifier->num_subdevs++;
-	}
-
-	return notifier->num_subdevs;
-
-error:
-	fwnode_handle_put(fwnode);
-	return -EINVAL;
-}
-
 static int isp_subdev_notifier_complete(struct v4l2_async_notifier *async)
 {
 	struct isp_device *isp = container_of(async, struct isp_device,
@@ -2256,15 +2210,17 @@ static int isp_probe(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
-	ret = isp_fwnodes_parse(&pdev->dev, &isp->notifier);
-	if (ret < 0)
-		return ret;
-
 	isp->autoidle = autoidle;
 
 	mutex_init(&isp->isp_mutex);
 	spin_lock_init(&isp->stat_lock);
 
+	ret = v4l2_async_notifier_parse_fwnode_endpoints(
+		&pdev->dev, &isp->notifier, sizeof(struct isp_async_subdev),
+		isp_fwnode_parse);
+	if (ret < 0)
+		goto error;
+
 	isp->dev = &pdev->dev;
 	isp->ref_count = 0;
 
@@ -2406,6 +2362,7 @@ static int isp_probe(struct platform_device *pdev)
 	isp_xclk_cleanup(isp);
 	__omap3isp_put(isp, false);
 error:
+	v4l2_async_notifier_cleanup(&isp->notifier);
 	mutex_destroy(&isp->isp_mutex);
 
 	return ret;
diff --git a/drivers/media/platform/omap3isp/isp.h b/drivers/media/platform/omap3isp/isp.h
index e528df6efc09..8b9043db94b3 100644
--- a/drivers/media/platform/omap3isp/isp.h
+++ b/drivers/media/platform/omap3isp/isp.h
@@ -220,14 +220,11 @@ struct isp_device {
 
 	unsigned int sbl_resources;
 	unsigned int subclk_resources;
-
-#define ISP_MAX_SUBDEVS		8
-	struct v4l2_subdev *subdevs[ISP_MAX_SUBDEVS];
 };
 
 struct isp_async_subdev {
-	struct isp_bus_cfg bus;
 	struct v4l2_async_subdev asd;
+	struct isp_bus_cfg bus;
 };
 
 #define v4l2_subdev_to_bus_cfg(sd) \
-- 
2.11.0

[PATCH v15 10/32] rcar-vin: Use generic parser for parsing fwnode endpoints

[Sakari Ailus]

Instead of using a custom driver implementation, use
v4l2_async_notifier_parse_fwnode_endpoints() to parse the fwnode endpoints
of the device.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
---
 drivers/media/platform/rcar-vin/rcar-core.c | 107 +++++++++-------------------
 drivers/media/platform/rcar-vin/rcar-dma.c  |  10 +--
 drivers/media/platform/rcar-vin/rcar-v4l2.c |  14 ++--
 drivers/media/platform/rcar-vin/rcar-vin.h  |   4 +-
 4 files changed, 46 insertions(+), 89 deletions(-)

diff --git a/drivers/media/platform/rcar-vin/rcar-core.c b/drivers/media/platform/rcar-vin/rcar-core.c
index 142de447aaaa..380288658601 100644
--- a/drivers/media/platform/rcar-vin/rcar-core.c
+++ b/drivers/media/platform/rcar-vin/rcar-core.c
@@ -21,6 +21,7 @@
 #include <linux/platform_device.h>
 #include <linux/pm_runtime.h>
 
+#include <media/v4l2-async.h>
 #include <media/v4l2-fwnode.h>
 
 #include "rcar-vin.h"
@@ -77,14 +78,14 @@ static int rvin_digital_notify_complete(struct v4l2_async_notifier *notifier)
 	int ret;
 
 	/* Verify subdevices mbus format */
-	if (!rvin_mbus_supported(&vin->digital)) {
+	if (!rvin_mbus_supported(vin->digital)) {
 		vin_err(vin, "Unsupported media bus format for %s\n",
-			vin->digital.subdev->name);
+			vin->digital->subdev->name);
 		return -EINVAL;
 	}
 
 	vin_dbg(vin, "Found media bus format for %s: %d\n",
-		vin->digital.subdev->name, vin->digital.code);
+		vin->digital->subdev->name, vin->digital->code);
 
 	ret = v4l2_device_register_subdev_nodes(&vin->v4l2_dev);
 	if (ret < 0) {
@@ -103,7 +104,7 @@ static void rvin_digital_notify_unbind(struct v4l2_async_notifier *notifier,
 
 	vin_dbg(vin, "unbind digital subdev %s\n", subdev->name);
 	rvin_v4l2_remove(vin);
-	vin->digital.subdev = NULL;
+	vin->digital->subdev = NULL;
 }
 
 static int rvin_digital_notify_bound(struct v4l2_async_notifier *notifier,
@@ -120,117 +121,71 @@ static int rvin_digital_notify_bound(struct v4l2_async_notifier *notifier,
 	ret = rvin_find_pad(subdev, MEDIA_PAD_FL_SOURCE);
 	if (ret < 0)
 		return ret;
-	vin->digital.source_pad = ret;
+	vin->digital->source_pad = ret;
 
 	ret = rvin_find_pad(subdev, MEDIA_PAD_FL_SINK);
-	vin->digital.sink_pad = ret < 0 ? 0 : ret;
+	vin->digital->sink_pad = ret < 0 ? 0 : ret;
 
-	vin->digital.subdev = subdev;
+	vin->digital->subdev = subdev;
 
 	vin_dbg(vin, "bound subdev %s source pad: %u sink pad: %u\n",
-		subdev->name, vin->digital.source_pad,
-		vin->digital.sink_pad);
+		subdev->name, vin->digital->source_pad,
+		vin->digital->sink_pad);
 
 	return 0;
 }
 
-static int rvin_digitial_parse_v4l2(struct rvin_dev *vin,
-				    struct device_node *ep,
-				    struct v4l2_mbus_config *mbus_cfg)
+static int rvin_digital_parse_v4l2(struct device *dev,
+				   struct v4l2_fwnode_endpoint *vep,
+				   struct v4l2_async_subdev *asd)
 {
-	struct v4l2_fwnode_endpoint v4l2_ep;
-	int ret;
+	struct rvin_dev *vin = dev_get_drvdata(dev);
+	struct rvin_graph_entity *rvge =
+		container_of(asd, struct rvin_graph_entity, asd);
 
-	ret = v4l2_fwnode_endpoint_parse(of_fwnode_handle(ep), &v4l2_ep);
-	if (ret) {
-		vin_err(vin, "Could not parse v4l2 endpoint\n");
-		return -EINVAL;
-	}
+	if (vep->base.port || vep->base.id)
+		return -ENOTCONN;
 
-	mbus_cfg->type = v4l2_ep.bus_type;
+	rvge->mbus_cfg.type = vep->bus_type;
 
-	switch (mbus_cfg->type) {
+	switch (rvge->mbus_cfg.type) {
 	case V4L2_MBUS_PARALLEL:
 		vin_dbg(vin, "Found PARALLEL media bus\n");
-		mbus_cfg->flags = v4l2_ep.bus.parallel.flags;
+		rvge->mbus_cfg.flags = vep->bus.parallel.flags;
 		break;
 	case V4L2_MBUS_BT656:
 		vin_dbg(vin, "Found BT656 media bus\n");
-		mbus_cfg->flags = 0;
+		rvge->mbus_cfg.flags = 0;
 		break;
 	default:
 		vin_err(vin, "Unknown media bus type\n");
 		return -EINVAL;
 	}
 
-	return 0;
-}
-
-static int rvin_digital_graph_parse(struct rvin_dev *vin)
-{
-	struct device_node *ep, *np;
-	int ret;
-
-	vin->digital.asd.match.fwnode.fwnode = NULL;
-	vin->digital.subdev = NULL;
-
-	/*
-	 * Port 0 id 0 is local digital input, try to get it.
-	 * Not all instances can or will have this, that is OK
-	 */
-	ep = of_graph_get_endpoint_by_regs(vin->dev->of_node, 0, 0);
-	if (!ep)
-		return 0;
-
-	np = of_graph_get_remote_port_parent(ep);
-	if (!np) {
-		vin_err(vin, "No remote parent for digital input\n");
-		of_node_put(ep);
-		return -EINVAL;
-	}
-	of_node_put(np);
-
-	ret = rvin_digitial_parse_v4l2(vin, ep, &vin->digital.mbus_cfg);
-	of_node_put(ep);
-	if (ret)
-		return ret;
-
-	vin->digital.asd.match.fwnode.fwnode = of_fwnode_handle(np);
-	vin->digital.asd.match_type = V4L2_ASYNC_MATCH_FWNODE;
+	vin->digital = rvge;
 
 	return 0;
 }
 
 static int rvin_digital_graph_init(struct rvin_dev *vin)
 {
-	struct v4l2_async_subdev **subdevs = NULL;
 	int ret;
 
-	ret = rvin_digital_graph_parse(vin);
+	ret = v4l2_async_notifier_parse_fwnode_endpoints(
+		vin->dev, &vin->notifier,
+		sizeof(struct rvin_graph_entity), rvin_digital_parse_v4l2);
 	if (ret)
 		return ret;
 
-	if (!vin->digital.asd.match.fwnode.fwnode) {
-		vin_dbg(vin, "No digital subdevice found\n");
+	if (!vin->digital)
 		return -ENODEV;
-	}
-
-	/* Register the subdevices notifier. */
-	subdevs = devm_kzalloc(vin->dev, sizeof(*subdevs), GFP_KERNEL);
-	if (subdevs == NULL)
-		return -ENOMEM;
-
-	subdevs[0] = &vin->digital.asd;
 
 	vin_dbg(vin, "Found digital subdevice %pOF\n",
-		to_of_node(subdevs[0]->match.fwnode.fwnode));
+		to_of_node(vin->digital->asd.match.fwnode.fwnode));
 
-	vin->notifier.num_subdevs = 1;
-	vin->notifier.subdevs = subdevs;
 	vin->notifier.bound = rvin_digital_notify_bound;
 	vin->notifier.unbind = rvin_digital_notify_unbind;
 	vin->notifier.complete = rvin_digital_notify_complete;
-
 	ret = v4l2_async_notifier_register(&vin->v4l2_dev, &vin->notifier);
 	if (ret < 0) {
 		vin_err(vin, "Notifier registration failed\n");
@@ -290,6 +245,8 @@ static int rcar_vin_probe(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
+	platform_set_drvdata(pdev, vin);
+
 	ret = rvin_digital_graph_init(vin);
 	if (ret < 0)
 		goto error;
@@ -297,11 +254,10 @@ static int rcar_vin_probe(struct platform_device *pdev)
 	pm_suspend_ignore_children(&pdev->dev, true);
 	pm_runtime_enable(&pdev->dev);
 
-	platform_set_drvdata(pdev, vin);
-
 	return 0;
 error:
 	rvin_dma_remove(vin);
+	v4l2_async_notifier_cleanup(&vin->notifier);
 
 	return ret;
 }
@@ -313,6 +269,7 @@ static int rcar_vin_remove(struct platform_device *pdev)
 	pm_runtime_disable(&pdev->dev);
 
 	v4l2_async_notifier_unregister(&vin->notifier);
+	v4l2_async_notifier_cleanup(&vin->notifier);
 
 	rvin_dma_remove(vin);
 
diff --git a/drivers/media/platform/rcar-vin/rcar-dma.c b/drivers/media/platform/rcar-vin/rcar-dma.c
index b136844499f6..23fdff7a7370 100644
--- a/drivers/media/platform/rcar-vin/rcar-dma.c
+++ b/drivers/media/platform/rcar-vin/rcar-dma.c
@@ -183,7 +183,7 @@ static int rvin_setup(struct rvin_dev *vin)
 	/*
 	 * Input interface
 	 */
-	switch (vin->digital.code) {
+	switch (vin->digital->code) {
 	case MEDIA_BUS_FMT_YUYV8_1X16:
 		/* BT.601/BT.1358 16bit YCbCr422 */
 		vnmc |= VNMC_INF_YUV16;
@@ -191,7 +191,7 @@ static int rvin_setup(struct rvin_dev *vin)
 		break;
 	case MEDIA_BUS_FMT_UYVY8_2X8:
 		/* BT.656 8bit YCbCr422 or BT.601 8bit YCbCr422 */
-		vnmc |= vin->digital.mbus_cfg.type == V4L2_MBUS_BT656 ?
+		vnmc |= vin->digital->mbus_cfg.type == V4L2_MBUS_BT656 ?
 			VNMC_INF_YUV8_BT656 : VNMC_INF_YUV8_BT601;
 		input_is_yuv = true;
 		break;
@@ -200,7 +200,7 @@ static int rvin_setup(struct rvin_dev *vin)
 		break;
 	case MEDIA_BUS_FMT_UYVY10_2X10:
 		/* BT.656 10bit YCbCr422 or BT.601 10bit YCbCr422 */
-		vnmc |= vin->digital.mbus_cfg.type == V4L2_MBUS_BT656 ?
+		vnmc |= vin->digital->mbus_cfg.type == V4L2_MBUS_BT656 ?
 			VNMC_INF_YUV10_BT656 : VNMC_INF_YUV10_BT601;
 		input_is_yuv = true;
 		break;
@@ -212,11 +212,11 @@ static int rvin_setup(struct rvin_dev *vin)
 	dmr2 = VNDMR2_FTEV | VNDMR2_VLV(1);
 
 	/* Hsync Signal Polarity Select */
-	if (!(vin->digital.mbus_cfg.flags & V4L2_MBUS_HSYNC_ACTIVE_LOW))
+	if (!(vin->digital->mbus_cfg.flags & V4L2_MBUS_HSYNC_ACTIVE_LOW))
 		dmr2 |= VNDMR2_HPS;
 
 	/* Vsync Signal Polarity Select */
-	if (!(vin->digital.mbus_cfg.flags & V4L2_MBUS_VSYNC_ACTIVE_LOW))
+	if (!(vin->digital->mbus_cfg.flags & V4L2_MBUS_VSYNC_ACTIVE_LOW))
 		dmr2 |= VNDMR2_VPS;
 
 	/*
diff --git a/drivers/media/platform/rcar-vin/rcar-v4l2.c b/drivers/media/platform/rcar-vin/rcar-v4l2.c
index dd37ea811680..b479b882da12 100644
--- a/drivers/media/platform/rcar-vin/rcar-v4l2.c
+++ b/drivers/media/platform/rcar-vin/rcar-v4l2.c
@@ -111,7 +111,7 @@ static int rvin_reset_format(struct rvin_dev *vin)
 	struct v4l2_mbus_framefmt *mf = &fmt.format;
 	int ret;
 
-	fmt.pad = vin->digital.source_pad;
+	fmt.pad = vin->digital->source_pad;
 
 	ret = v4l2_subdev_call(vin_to_source(vin), pad, get_fmt, NULL, &fmt);
 	if (ret)
@@ -172,13 +172,13 @@ static int __rvin_try_format_source(struct rvin_dev *vin,
 
 	sd = vin_to_source(vin);
 
-	v4l2_fill_mbus_format(&format.format, pix, vin->digital.code);
+	v4l2_fill_mbus_format(&format.format, pix, vin->digital->code);
 
 	pad_cfg = v4l2_subdev_alloc_pad_config(sd);
 	if (pad_cfg == NULL)
 		return -ENOMEM;
 
-	format.pad = vin->digital.source_pad;
+	format.pad = vin->digital->source_pad;
 
 	field = pix->field;
 
@@ -555,7 +555,7 @@ static int rvin_enum_dv_timings(struct file *file, void *priv_fh,
 	if (timings->pad)
 		return -EINVAL;
 
-	timings->pad = vin->digital.sink_pad;
+	timings->pad = vin->digital->sink_pad;
 
 	ret = v4l2_subdev_call(sd, pad, enum_dv_timings, timings);
 
@@ -607,7 +607,7 @@ static int rvin_dv_timings_cap(struct file *file, void *priv_fh,
 	if (cap->pad)
 		return -EINVAL;
 
-	cap->pad = vin->digital.sink_pad;
+	cap->pad = vin->digital->sink_pad;
 
 	ret = v4l2_subdev_call(sd, pad, dv_timings_cap, cap);
 
@@ -625,7 +625,7 @@ static int rvin_g_edid(struct file *file, void *fh, struct v4l2_edid *edid)
 	if (edid->pad)
 		return -EINVAL;
 
-	edid->pad = vin->digital.sink_pad;
+	edid->pad = vin->digital->sink_pad;
 
 	ret = v4l2_subdev_call(sd, pad, get_edid, edid);
 
@@ -643,7 +643,7 @@ static int rvin_s_edid(struct file *file, void *fh, struct v4l2_edid *edid)
 	if (edid->pad)
 		return -EINVAL;
 
-	edid->pad = vin->digital.sink_pad;
+	edid->pad = vin->digital->sink_pad;
 
 	ret = v4l2_subdev_call(sd, pad, set_edid, edid);
 
diff --git a/drivers/media/platform/rcar-vin/rcar-vin.h b/drivers/media/platform/rcar-vin/rcar-vin.h
index 9bfb5a7c4dc4..5382078143fb 100644
--- a/drivers/media/platform/rcar-vin/rcar-vin.h
+++ b/drivers/media/platform/rcar-vin/rcar-vin.h
@@ -126,7 +126,7 @@ struct rvin_dev {
 	struct v4l2_device v4l2_dev;
 	struct v4l2_ctrl_handler ctrl_handler;
 	struct v4l2_async_notifier notifier;
-	struct rvin_graph_entity digital;
+	struct rvin_graph_entity *digital;
 
 	struct mutex lock;
 	struct vb2_queue queue;
@@ -145,7 +145,7 @@ struct rvin_dev {
 	struct v4l2_rect compose;
 };
 
-#define vin_to_source(vin)		vin->digital.subdev
+#define vin_to_source(vin)		((vin)->digital->subdev)
 
 /* Debug */
 #define vin_dbg(d, fmt, arg...)		dev_dbg(d->dev, fmt, ##arg)
-- 
2.11.0

[PATCH v15 11/32] omap3isp: Fix check for our own sub-devices

[Sakari Ailus]

We only want to link sub-devices that were bound to the async notifier the
isp driver registered but there may be other sub-devices in the
v4l2_device as well. Check for the correct async notifier.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
---
 drivers/media/platform/omap3isp/isp.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/media/platform/omap3isp/isp.c b/drivers/media/platform/omap3isp/isp.c
index 97a5206b6ddc..4afd7ba4fad6 100644
--- a/drivers/media/platform/omap3isp/isp.c
+++ b/drivers/media/platform/omap3isp/isp.c
@@ -2155,7 +2155,7 @@ static int isp_subdev_notifier_complete(struct v4l2_async_notifier *async)
 		return ret;
 
 	list_for_each_entry(sd, &v4l2_dev->subdevs, list) {
-		if (!sd->asd)
+		if (sd->notifier != &isp->notifier)
 			continue;
 
 		ret = isp_link_entity(isp, &sd->entity,
-- 
2.11.0

[PATCH v15 12/32] omap3isp: Print the name of the entity where no source pads could be found

[Sakari Ailus]

If no source pads are found in an entity, print the name of the entity.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
---
 drivers/media/platform/omap3isp/isp.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/media/platform/omap3isp/isp.c b/drivers/media/platform/omap3isp/isp.c
index 4afd7ba4fad6..35687c9707e0 100644
--- a/drivers/media/platform/omap3isp/isp.c
+++ b/drivers/media/platform/omap3isp/isp.c
@@ -1669,8 +1669,8 @@ static int isp_link_entity(
 			break;
 	}
 	if (i == entity->num_pads) {
-		dev_err(isp->dev, "%s: no source pad in external entity\n",
-			__func__);
+		dev_err(isp->dev, "%s: no source pad in external entity %s\n",
+			__func__, entity->name);
 		return -EINVAL;
 	}
 
-- 
2.11.0

[PATCH v15 13/32] v4l: async: Move async subdev notifier operations to a separate structure

[Sakari Ailus]

From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

The async subdev notifier .bound(), .unbind() and .complete() operations
are function pointers stored directly in the v4l2_async_subdev
structure. As the structure isn't immutable, this creates a potential
security risk as the function pointers are mutable.

To fix this, move the function pointers to a new
v4l2_async_subdev_operations structure that can be made const in
drivers.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
---
 drivers/media/platform/am437x/am437x-vpfe.c    |  8 +++++--
 drivers/media/platform/atmel/atmel-isc.c       | 10 ++++++---
 drivers/media/platform/atmel/atmel-isi.c       | 10 ++++++---
 drivers/media/platform/davinci/vpif_capture.c  |  8 +++++--
 drivers/media/platform/davinci/vpif_display.c  |  8 +++++--
 drivers/media/platform/exynos4-is/media-dev.c  |  8 +++++--
 drivers/media/platform/omap3isp/isp.c          |  6 +++++-
 drivers/media/platform/pxa_camera.c            |  8 +++++--
 drivers/media/platform/qcom/camss-8x16/camss.c |  8 +++++--
 drivers/media/platform/rcar-vin/rcar-core.c    | 10 ++++++---
 drivers/media/platform/rcar_drif.c             | 10 ++++++---
 drivers/media/platform/soc_camera/soc_camera.c | 14 ++++++------
 drivers/media/platform/stm32/stm32-dcmi.c      | 10 ++++++---
 drivers/media/platform/ti-vpe/cal.c            |  8 +++++--
 drivers/media/platform/xilinx/xilinx-vipp.c    |  8 +++++--
 drivers/media/v4l2-core/v4l2-async.c           | 30 ++++++++++++--------------
 drivers/staging/media/imx/imx-media-dev.c      |  8 +++++--
 include/media/v4l2-async.h                     | 29 ++++++++++++++++---------
 18 files changed, 135 insertions(+), 66 deletions(-)

diff --git a/drivers/media/platform/am437x/am437x-vpfe.c b/drivers/media/platform/am437x/am437x-vpfe.c
index dfcc484cab89..0997c640191d 100644
--- a/drivers/media/platform/am437x/am437x-vpfe.c
+++ b/drivers/media/platform/am437x/am437x-vpfe.c
@@ -2417,6 +2417,11 @@ static int vpfe_async_complete(struct v4l2_async_notifier *notifier)
 	return vpfe_probe_complete(vpfe);
 }
 
+static const struct v4l2_async_notifier_operations vpfe_async_ops = {
+	.bound = vpfe_async_bound,
+	.complete = vpfe_async_complete,
+};
+
 static struct vpfe_config *
 vpfe_get_pdata(struct platform_device *pdev)
 {
@@ -2590,8 +2595,7 @@ static int vpfe_probe(struct platform_device *pdev)
 
 	vpfe->notifier.subdevs = vpfe->cfg->asd;
 	vpfe->notifier.num_subdevs = ARRAY_SIZE(vpfe->cfg->asd);
-	vpfe->notifier.bound = vpfe_async_bound;
-	vpfe->notifier.complete = vpfe_async_complete;
+	vpfe->notifier.ops = &vpfe_async_ops;
 	ret = v4l2_async_notifier_register(&vpfe->v4l2_dev,
 						&vpfe->notifier);
 	if (ret) {
diff --git a/drivers/media/platform/atmel/atmel-isc.c b/drivers/media/platform/atmel/atmel-isc.c
index 2f8e345d297e..382fe355e616 100644
--- a/drivers/media/platform/atmel/atmel-isc.c
+++ b/drivers/media/platform/atmel/atmel-isc.c
@@ -1637,6 +1637,12 @@ static int isc_async_complete(struct v4l2_async_notifier *notifier)
 	return 0;
 }
 
+static const struct v4l2_async_notifier_operations isc_async_ops = {
+	.bound = isc_async_bound,
+	.unbind = isc_async_unbind,
+	.complete = isc_async_complete,
+};
+
 static void isc_subdev_cleanup(struct isc_device *isc)
 {
 	struct isc_subdev_entity *subdev_entity;
@@ -1849,9 +1855,7 @@ static int atmel_isc_probe(struct platform_device *pdev)
 	list_for_each_entry(subdev_entity, &isc->subdev_entities, list) {
 		subdev_entity->notifier.subdevs = &subdev_entity->asd;
 		subdev_entity->notifier.num_subdevs = 1;
-		subdev_entity->notifier.bound = isc_async_bound;
-		subdev_entity->notifier.unbind = isc_async_unbind;
-		subdev_entity->notifier.complete = isc_async_complete;
+		subdev_entity->notifier.ops = &isc_async_ops;
 
 		ret = v4l2_async_notifier_register(&isc->v4l2_dev,
 						   &subdev_entity->notifier);
diff --git a/drivers/media/platform/atmel/atmel-isi.c b/drivers/media/platform/atmel/atmel-isi.c
index 463c0146915e..e900995143a3 100644
--- a/drivers/media/platform/atmel/atmel-isi.c
+++ b/drivers/media/platform/atmel/atmel-isi.c
@@ -1103,6 +1103,12 @@ static int isi_graph_notify_bound(struct v4l2_async_notifier *notifier,
 	return 0;
 }
 
+static const struct v4l2_async_notifier_operations isi_graph_notify_ops = {
+	.bound = isi_graph_notify_bound,
+	.unbind = isi_graph_notify_unbind,
+	.complete = isi_graph_notify_complete,
+};
+
 static int isi_graph_parse(struct atmel_isi *isi, struct device_node *node)
 {
 	struct device_node *ep = NULL;
@@ -1150,9 +1156,7 @@ static int isi_graph_init(struct atmel_isi *isi)
 
 	isi->notifier.subdevs = subdevs;
 	isi->notifier.num_subdevs = 1;
-	isi->notifier.bound = isi_graph_notify_bound;
-	isi->notifier.unbind = isi_graph_notify_unbind;
-	isi->notifier.complete = isi_graph_notify_complete;
+	isi->notifier.ops = &isi_graph_notify_ops;
 
 	ret = v4l2_async_notifier_register(&isi->v4l2_dev, &isi->notifier);
 	if (ret < 0) {
diff --git a/drivers/media/platform/davinci/vpif_capture.c b/drivers/media/platform/davinci/vpif_capture.c
index 0ef36cec21d1..a89367ab1e06 100644
--- a/drivers/media/platform/davinci/vpif_capture.c
+++ b/drivers/media/platform/davinci/vpif_capture.c
@@ -1500,6 +1500,11 @@ static int vpif_async_complete(struct v4l2_async_notifier *notifier)
 	return vpif_probe_complete();
 }
 
+static const struct v4l2_async_notifier_operations vpif_async_ops = {
+	.bound = vpif_async_bound,
+	.complete = vpif_async_complete,
+};
+
 static struct vpif_capture_config *
 vpif_capture_get_pdata(struct platform_device *pdev)
 {
@@ -1691,8 +1696,7 @@ static __init int vpif_probe(struct platform_device *pdev)
 	} else {
 		vpif_obj.notifier.subdevs = vpif_obj.config->asd;
 		vpif_obj.notifier.num_subdevs = vpif_obj.config->asd_sizes[0];
-		vpif_obj.notifier.bound = vpif_async_bound;
-		vpif_obj.notifier.complete = vpif_async_complete;
+		vpif_obj.notifier.ops = &vpif_async_ops;
 		err = v4l2_async_notifier_register(&vpif_obj.v4l2_dev,
 						   &vpif_obj.notifier);
 		if (err) {
diff --git a/drivers/media/platform/davinci/vpif_display.c b/drivers/media/platform/davinci/vpif_display.c
index 56fe4e5b396e..ff2f75a328c9 100644
--- a/drivers/media/platform/davinci/vpif_display.c
+++ b/drivers/media/platform/davinci/vpif_display.c
@@ -1232,6 +1232,11 @@ static int vpif_async_complete(struct v4l2_async_notifier *notifier)
 	return vpif_probe_complete();
 }
 
+static const struct v4l2_async_notifier_operations vpif_async_ops = {
+	.bound = vpif_async_bound,
+	.complete = vpif_async_complete,
+};
+
 /*
  * vpif_probe: This function creates device entries by register itself to the
  * V4L2 driver and initializes fields of each channel objects
@@ -1313,8 +1318,7 @@ static __init int vpif_probe(struct platform_device *pdev)
 	} else {
 		vpif_obj.notifier.subdevs = vpif_obj.config->asd;
 		vpif_obj.notifier.num_subdevs = vpif_obj.config->asd_sizes[0];
-		vpif_obj.notifier.bound = vpif_async_bound;
-		vpif_obj.notifier.complete = vpif_async_complete;
+		vpif_obj.notifier.ops = &vpif_async_ops;
 		err = v4l2_async_notifier_register(&vpif_obj.v4l2_dev,
 						   &vpif_obj.notifier);
 		if (err) {
diff --git a/drivers/media/platform/exynos4-is/media-dev.c b/drivers/media/platform/exynos4-is/media-dev.c
index d4656d5175d7..c15596b56dc9 100644
--- a/drivers/media/platform/exynos4-is/media-dev.c
+++ b/drivers/media/platform/exynos4-is/media-dev.c
@@ -1405,6 +1405,11 @@ static int subdev_notifier_complete(struct v4l2_async_notifier *notifier)
 	return media_device_register(&fmd->media_dev);
 }
 
+static const struct v4l2_async_notifier_operations subdev_notifier_ops = {
+	.bound = subdev_notifier_bound,
+	.complete = subdev_notifier_complete,
+};
+
 static int fimc_md_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
@@ -1479,8 +1484,7 @@ static int fimc_md_probe(struct platform_device *pdev)
 	if (fmd->num_sensors > 0) {
 		fmd->subdev_notifier.subdevs = fmd->async_subdevs;
 		fmd->subdev_notifier.num_subdevs = fmd->num_sensors;
-		fmd->subdev_notifier.bound = subdev_notifier_bound;
-		fmd->subdev_notifier.complete = subdev_notifier_complete;
+		fmd->subdev_notifier.ops = &subdev_notifier_ops;
 		fmd->num_sensors = 0;
 
 		ret = v4l2_async_notifier_register(&fmd->v4l2_dev,
diff --git a/drivers/media/platform/omap3isp/isp.c b/drivers/media/platform/omap3isp/isp.c
index 35687c9707e0..b7ff3842afc0 100644
--- a/drivers/media/platform/omap3isp/isp.c
+++ b/drivers/media/platform/omap3isp/isp.c
@@ -2171,6 +2171,10 @@ static int isp_subdev_notifier_complete(struct v4l2_async_notifier *async)
 	return media_device_register(&isp->media_dev);
 }
 
+static const struct v4l2_async_notifier_operations isp_subdev_notifier_ops = {
+	.complete = isp_subdev_notifier_complete,
+};
+
 /*
  * isp_probe - Probe ISP platform device
  * @pdev: Pointer to ISP platform device
@@ -2341,7 +2345,7 @@ static int isp_probe(struct platform_device *pdev)
 	if (ret < 0)
 		goto error_register_entities;
 
-	isp->notifier.complete = isp_subdev_notifier_complete;
+	isp->notifier.ops = &isp_subdev_notifier_ops;
 
 	ret = v4l2_async_notifier_register(&isp->v4l2_dev, &isp->notifier);
 	if (ret)
diff --git a/drivers/media/platform/pxa_camera.c b/drivers/media/platform/pxa_camera.c
index edca993c2b1f..9d3f0cb1d95a 100644
--- a/drivers/media/platform/pxa_camera.c
+++ b/drivers/media/platform/pxa_camera.c
@@ -2221,6 +2221,11 @@ static void pxa_camera_sensor_unbind(struct v4l2_async_notifier *notifier,
 	mutex_unlock(&pcdev->mlock);
 }
 
+static const struct v4l2_async_notifier_operations pxa_camera_sensor_ops = {
+	.bound = pxa_camera_sensor_bound,
+	.unbind = pxa_camera_sensor_unbind,
+};
+
 /*
  * Driver probe, remove, suspend and resume operations
  */
@@ -2489,8 +2494,7 @@ static int pxa_camera_probe(struct platform_device *pdev)
 	pcdev->asds[0] = &pcdev->asd;
 	pcdev->notifier.subdevs = pcdev->asds;
 	pcdev->notifier.num_subdevs = 1;
-	pcdev->notifier.bound = pxa_camera_sensor_bound;
-	pcdev->notifier.unbind = pxa_camera_sensor_unbind;
+	pcdev->notifier.ops = &pxa_camera_sensor_ops;
 
 	if (!of_have_populated_dt())
 		pcdev->asd.match_type = V4L2_ASYNC_MATCH_I2C;
diff --git a/drivers/media/platform/qcom/camss-8x16/camss.c b/drivers/media/platform/qcom/camss-8x16/camss.c
index a3760b5dd1d1..390a42c17b66 100644
--- a/drivers/media/platform/qcom/camss-8x16/camss.c
+++ b/drivers/media/platform/qcom/camss-8x16/camss.c
@@ -601,6 +601,11 @@ static int camss_subdev_notifier_complete(struct v4l2_async_notifier *async)
 	return media_device_register(&camss->media_dev);
 }
 
+static const struct v4l2_async_notifier_operations camss_subdev_notifier_ops = {
+	.bound = camss_subdev_notifier_bound,
+	.complete = camss_subdev_notifier_complete,
+};
+
 static const struct media_device_ops camss_media_ops = {
 	.link_notify = v4l2_pipeline_link_notify,
 };
@@ -655,8 +660,7 @@ static int camss_probe(struct platform_device *pdev)
 		goto err_register_entities;
 
 	if (camss->notifier.num_subdevs) {
-		camss->notifier.bound = camss_subdev_notifier_bound;
-		camss->notifier.complete = camss_subdev_notifier_complete;
+		camss->notifier.ops = &camss_subdev_notifier_ops;
 
 		ret = v4l2_async_notifier_register(&camss->v4l2_dev,
 						   &camss->notifier);
diff --git a/drivers/media/platform/rcar-vin/rcar-core.c b/drivers/media/platform/rcar-vin/rcar-core.c
index 380288658601..108d776f3265 100644
--- a/drivers/media/platform/rcar-vin/rcar-core.c
+++ b/drivers/media/platform/rcar-vin/rcar-core.c
@@ -134,6 +134,12 @@ static int rvin_digital_notify_bound(struct v4l2_async_notifier *notifier,
 
 	return 0;
 }
+static const struct v4l2_async_notifier_operations rvin_digital_notify_ops = {
+	.bound = rvin_digital_notify_bound,
+	.unbind = rvin_digital_notify_unbind,
+	.complete = rvin_digital_notify_complete,
+};
+
 
 static int rvin_digital_parse_v4l2(struct device *dev,
 				   struct v4l2_fwnode_endpoint *vep,
@@ -183,9 +189,7 @@ static int rvin_digital_graph_init(struct rvin_dev *vin)
 	vin_dbg(vin, "Found digital subdevice %pOF\n",
 		to_of_node(vin->digital->asd.match.fwnode.fwnode));
 
-	vin->notifier.bound = rvin_digital_notify_bound;
-	vin->notifier.unbind = rvin_digital_notify_unbind;
-	vin->notifier.complete = rvin_digital_notify_complete;
+	vin->notifier.ops = &rvin_digital_notify_ops;
 	ret = v4l2_async_notifier_register(&vin->v4l2_dev, &vin->notifier);
 	if (ret < 0) {
 		vin_err(vin, "Notifier registration failed\n");
diff --git a/drivers/media/platform/rcar_drif.c b/drivers/media/platform/rcar_drif.c
index 522364ff0d5d..0b2214d6d621 100644
--- a/drivers/media/platform/rcar_drif.c
+++ b/drivers/media/platform/rcar_drif.c
@@ -1185,6 +1185,12 @@ static int rcar_drif_notify_complete(struct v4l2_async_notifier *notifier)
 	return ret;
 }
 
+static const struct v4l2_async_notifier_operations rcar_drif_notify_ops = {
+	.bound = rcar_drif_notify_bound,
+	.unbind = rcar_drif_notify_unbind,
+	.complete = rcar_drif_notify_complete,
+};
+
 /* Read endpoint properties */
 static void rcar_drif_get_ep_properties(struct rcar_drif_sdr *sdr,
 					struct fwnode_handle *fwnode)
@@ -1347,9 +1353,7 @@ static int rcar_drif_sdr_probe(struct rcar_drif_sdr *sdr)
 	if (ret)
 		goto error;
 
-	sdr->notifier.bound = rcar_drif_notify_bound;
-	sdr->notifier.unbind = rcar_drif_notify_unbind;
-	sdr->notifier.complete = rcar_drif_notify_complete;
+	sdr->notifier.ops = &rcar_drif_notify_ops;
 
 	/* Register notifier */
 	ret = v4l2_async_notifier_register(&sdr->v4l2_dev, &sdr->notifier);
diff --git a/drivers/media/platform/soc_camera/soc_camera.c b/drivers/media/platform/soc_camera/soc_camera.c
index 1f3c450c7a69..916ff68b73d4 100644
--- a/drivers/media/platform/soc_camera/soc_camera.c
+++ b/drivers/media/platform/soc_camera/soc_camera.c
@@ -1391,6 +1391,12 @@ static int soc_camera_async_complete(struct v4l2_async_notifier *notifier)
 	return 0;
 }
 
+static const struct v4l2_async_notifier_operations soc_camera_async_ops = {
+	.bound = soc_camera_async_bound,
+	.unbind = soc_camera_async_unbind,
+	.complete = soc_camera_async_complete,
+};
+
 static int scan_async_group(struct soc_camera_host *ici,
 			    struct v4l2_async_subdev **asd, unsigned int size)
 {
@@ -1437,9 +1443,7 @@ static int scan_async_group(struct soc_camera_host *ici,
 
 	sasc->notifier.subdevs = asd;
 	sasc->notifier.num_subdevs = size;
-	sasc->notifier.bound = soc_camera_async_bound;
-	sasc->notifier.unbind = soc_camera_async_unbind;
-	sasc->notifier.complete = soc_camera_async_complete;
+	sasc->notifier.ops = &soc_camera_async_ops;
 
 	icd->sasc = sasc;
 	icd->parent = ici->v4l2_dev.dev;
@@ -1537,9 +1541,7 @@ static int soc_of_bind(struct soc_camera_host *ici,
 
 	sasc->notifier.subdevs = &info->subdev;
 	sasc->notifier.num_subdevs = 1;
-	sasc->notifier.bound = soc_camera_async_bound;
-	sasc->notifier.unbind = soc_camera_async_unbind;
-	sasc->notifier.complete = soc_camera_async_complete;
+	sasc->notifier.ops = &soc_camera_async_ops;
 
 	icd->sasc = sasc;
 	icd->parent = ici->v4l2_dev.dev;
diff --git a/drivers/media/platform/stm32/stm32-dcmi.c b/drivers/media/platform/stm32/stm32-dcmi.c
index 35ba6f211b79..ac4c450a6c7d 100644
--- a/drivers/media/platform/stm32/stm32-dcmi.c
+++ b/drivers/media/platform/stm32/stm32-dcmi.c
@@ -1495,6 +1495,12 @@ static int dcmi_graph_notify_bound(struct v4l2_async_notifier *notifier,
 	return 0;
 }
 
+static const struct v4l2_async_notifier_operations dcmi_graph_notify_ops = {
+	.bound = dcmi_graph_notify_bound,
+	.unbind = dcmi_graph_notify_unbind,
+	.complete = dcmi_graph_notify_complete,
+};
+
 static int dcmi_graph_parse(struct stm32_dcmi *dcmi, struct device_node *node)
 {
 	struct device_node *ep = NULL;
@@ -1542,9 +1548,7 @@ static int dcmi_graph_init(struct stm32_dcmi *dcmi)
 
 	dcmi->notifier.subdevs = subdevs;
 	dcmi->notifier.num_subdevs = 1;
-	dcmi->notifier.bound = dcmi_graph_notify_bound;
-	dcmi->notifier.unbind = dcmi_graph_notify_unbind;
-	dcmi->notifier.complete = dcmi_graph_notify_complete;
+	dcmi->notifier.ops = &dcmi_graph_notify_ops;
 
 	ret = v4l2_async_notifier_register(&dcmi->v4l2_dev, &dcmi->notifier);
 	if (ret < 0) {
diff --git a/drivers/media/platform/ti-vpe/cal.c b/drivers/media/platform/ti-vpe/cal.c
index 42e383a48ffe..8b586c864524 100644
--- a/drivers/media/platform/ti-vpe/cal.c
+++ b/drivers/media/platform/ti-vpe/cal.c
@@ -1522,6 +1522,11 @@ static int cal_async_complete(struct v4l2_async_notifier *notifier)
 	return 0;
 }
 
+static const struct v4l2_async_notifier_operations cal_async_ops = {
+	.bound = cal_async_bound,
+	.complete = cal_async_complete,
+};
+
 static int cal_complete_ctx(struct cal_ctx *ctx)
 {
 	struct video_device *vfd;
@@ -1736,8 +1741,7 @@ static int of_cal_create_instance(struct cal_ctx *ctx, int inst)
 	ctx->asd_list[0] = asd;
 	ctx->notifier.subdevs = ctx->asd_list;
 	ctx->notifier.num_subdevs = 1;
-	ctx->notifier.bound = cal_async_bound;
-	ctx->notifier.complete = cal_async_complete;
+	ctx->notifier.ops = &cal_async_ops;
 	ret = v4l2_async_notifier_register(&ctx->v4l2_dev,
 					   &ctx->notifier);
 	if (ret) {
diff --git a/drivers/media/platform/xilinx/xilinx-vipp.c b/drivers/media/platform/xilinx/xilinx-vipp.c
index ebfdf334d99c..d881cf09876d 100644
--- a/drivers/media/platform/xilinx/xilinx-vipp.c
+++ b/drivers/media/platform/xilinx/xilinx-vipp.c
@@ -351,6 +351,11 @@ static int xvip_graph_notify_bound(struct v4l2_async_notifier *notifier,
 	return -EINVAL;
 }
 
+static const struct v4l2_async_notifier_operations xvip_graph_notify_ops = {
+	.bound = xvip_graph_notify_bound,
+	.complete = xvip_graph_notify_complete,
+};
+
 static int xvip_graph_parse_one(struct xvip_composite_device *xdev,
 				struct device_node *node)
 {
@@ -548,8 +553,7 @@ static int xvip_graph_init(struct xvip_composite_device *xdev)
 
 	xdev->notifier.subdevs = subdevs;
 	xdev->notifier.num_subdevs = num_subdevs;
-	xdev->notifier.bound = xvip_graph_notify_bound;
-	xdev->notifier.complete = xvip_graph_notify_complete;
+	xdev->notifier.ops = &xvip_graph_notify_ops;
 
 	ret = v4l2_async_notifier_register(&xdev->v4l2_dev, &xdev->notifier);
 	if (ret < 0) {
diff --git a/drivers/media/v4l2-core/v4l2-async.c b/drivers/media/v4l2-core/v4l2-async.c
index 46aebfc75e43..9d6fc5f25619 100644
--- a/drivers/media/v4l2-core/v4l2-async.c
+++ b/drivers/media/v4l2-core/v4l2-async.c
@@ -102,16 +102,16 @@ static int v4l2_async_match_notify(struct v4l2_async_notifier *notifier,
 {
 	int ret;
 
-	if (notifier->bound) {
-		ret = notifier->bound(notifier, sd, asd);
+	if (notifier->ops->bound) {
+		ret = notifier->ops->bound(notifier, sd, asd);
 		if (ret < 0)
 			return ret;
 	}
 
 	ret = v4l2_device_register_subdev(notifier->v4l2_dev, sd);
 	if (ret < 0) {
-		if (notifier->unbind)
-			notifier->unbind(notifier, sd, asd);
+		if (notifier->ops->unbind)
+			notifier->ops->unbind(notifier, sd, asd);
 		return ret;
 	}
 
@@ -140,9 +140,8 @@ static void v4l2_async_notifier_unbind_all_subdevs(
 	struct v4l2_subdev *sd, *tmp;
 
 	list_for_each_entry_safe(sd, tmp, &notifier->done, async_list) {
-		if (notifier->unbind)
-			notifier->unbind(notifier, sd, sd->asd);
-
+		if (notifier->ops->unbind)
+			notifier->ops->unbind(notifier, sd, sd->asd);
 		v4l2_async_cleanup(sd);
 
 		list_move(&sd->async_list, &subdev_list);
@@ -199,8 +198,8 @@ int v4l2_async_notifier_register(struct v4l2_device *v4l2_dev,
 		}
 	}
 
-	if (list_empty(&notifier->waiting) && notifier->complete) {
-		ret = notifier->complete(notifier);
+	if (list_empty(&notifier->waiting) && notifier->ops->complete) {
+		ret = notifier->ops->complete(notifier);
 		if (ret)
 			goto err_complete;
 	}
@@ -297,10 +296,10 @@ int v4l2_async_register_subdev(struct v4l2_subdev *sd)
 		if (ret)
 			goto err_unlock;
 
-		if (!list_empty(&notifier->waiting) || !notifier->complete)
+		if (!list_empty(&notifier->waiting) || !notifier->ops->complete)
 			goto out_unlock;
 
-		ret = notifier->complete(notifier);
+		ret = notifier->ops->complete(notifier);
 		if (ret)
 			goto err_cleanup;
 
@@ -316,9 +315,8 @@ int v4l2_async_register_subdev(struct v4l2_subdev *sd)
 	return 0;
 
 err_cleanup:
-	if (notifier->unbind)
-		notifier->unbind(notifier, sd, sd->asd);
-
+	if (notifier->ops->unbind)
+		notifier->ops->unbind(notifier, sd, sd->asd);
 	v4l2_async_cleanup(sd);
 
 err_unlock:
@@ -337,8 +335,8 @@ void v4l2_async_unregister_subdev(struct v4l2_subdev *sd)
 
 		list_add(&sd->asd->list, &notifier->waiting);
 
-		if (notifier->unbind)
-			notifier->unbind(notifier, sd, sd->asd);
+		if (notifier->ops->unbind)
+			notifier->ops->unbind(notifier, sd, sd->asd);
 	}
 
 	v4l2_async_cleanup(sd);
diff --git a/drivers/staging/media/imx/imx-media-dev.c b/drivers/staging/media/imx/imx-media-dev.c
index b55e5ebba8b4..47c4c954fed5 100644
--- a/drivers/staging/media/imx/imx-media-dev.c
+++ b/drivers/staging/media/imx/imx-media-dev.c
@@ -440,6 +440,11 @@ static int imx_media_probe_complete(struct v4l2_async_notifier *notifier)
 	return media_device_register(&imxmd->md);
 }
 
+static const struct v4l2_async_notifier_operations imx_media_subdev_ops = {
+	.bound = imx_media_subdev_bound,
+	.complete = imx_media_probe_complete,
+};
+
 /*
  * adds controls to a video device from an entity subdevice.
  * Continues upstream from the entity's sink pads.
@@ -608,8 +613,7 @@ static int imx_media_probe(struct platform_device *pdev)
 
 	/* prepare the async subdev notifier and register it */
 	imxmd->subdev_notifier.subdevs = imxmd->async_ptrs;
-	imxmd->subdev_notifier.bound = imx_media_subdev_bound;
-	imxmd->subdev_notifier.complete = imx_media_probe_complete;
+	imxmd->subdev_notifier.ops = &imx_media_subdev_ops;
 	ret = v4l2_async_notifier_register(&imxmd->v4l2_dev,
 					   &imxmd->subdev_notifier);
 	if (ret) {
diff --git a/include/media/v4l2-async.h b/include/media/v4l2-async.h
index 329aeebd1a80..68606afb5ef9 100644
--- a/include/media/v4l2-async.h
+++ b/include/media/v4l2-async.h
@@ -18,6 +18,7 @@ struct device;
 struct device_node;
 struct v4l2_device;
 struct v4l2_subdev;
+struct v4l2_async_notifier;
 
 /* A random max subdevice number, used to allocate an array on stack */
 #define V4L2_MAX_SUBDEVS 128U
@@ -79,8 +80,25 @@ struct v4l2_async_subdev {
 };
 
 /**
+ * struct v4l2_async_notifier_operations - Asynchronous V4L2 notifier operations
+ * @bound:	a subdevice driver has successfully probed one of the subdevices
+ * @complete:	all subdevices have been probed successfully
+ * @unbind:	a subdevice is leaving
+ */
+struct v4l2_async_notifier_operations {
+	int (*bound)(struct v4l2_async_notifier *notifier,
+		     struct v4l2_subdev *subdev,
+		     struct v4l2_async_subdev *asd);
+	int (*complete)(struct v4l2_async_notifier *notifier);
+	void (*unbind)(struct v4l2_async_notifier *notifier,
+		       struct v4l2_subdev *subdev,
+		       struct v4l2_async_subdev *asd);
+};
+
+/**
  * struct v4l2_async_notifier - v4l2_device notifier data
  *
+ * @ops:	notifier operations
  * @num_subdevs: number of subdevices used in the subdevs array
  * @max_subdevs: number of subdevices allocated in the subdevs array
  * @subdevs:	array of pointers to subdevice descriptors
@@ -88,11 +106,9 @@ struct v4l2_async_subdev {
  * @waiting:	list of struct v4l2_async_subdev, waiting for their drivers
  * @done:	list of struct v4l2_subdev, already probed
  * @list:	member in a global list of notifiers
- * @bound:	a subdevice driver has successfully probed one of subdevices
- * @complete:	all subdevices have been probed successfully
- * @unbind:	a subdevice is leaving
  */
 struct v4l2_async_notifier {
+	const struct v4l2_async_notifier_operations *ops;
 	unsigned int num_subdevs;
 	unsigned int max_subdevs;
 	struct v4l2_async_subdev **subdevs;
@@ -100,13 +116,6 @@ struct v4l2_async_notifier {
 	struct list_head waiting;
 	struct list_head done;
 	struct list_head list;
-	int (*bound)(struct v4l2_async_notifier *notifier,
-		     struct v4l2_subdev *subdev,
-		     struct v4l2_async_subdev *asd);
-	int (*complete)(struct v4l2_async_notifier *notifier);
-	void (*unbind)(struct v4l2_async_notifier *notifier,
-		       struct v4l2_subdev *subdev,
-		       struct v4l2_async_subdev *asd);
 };
 
 /**
-- 
2.11.0

[PATCH v15 14/32] v4l: async: Introduce helpers for calling async ops callbacks

[Sakari Ailus]

Add three helper functions to call async operations callbacks. Besides
simplifying callbacks, this allows async notifiers to have no ops set,
i.e. it can be left NULL.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
---
 drivers/media/v4l2-core/v4l2-async.c | 56 +++++++++++++++++++++++++-----------
 1 file changed, 39 insertions(+), 17 deletions(-)

diff --git a/drivers/media/v4l2-core/v4l2-async.c b/drivers/media/v4l2-core/v4l2-async.c
index 9d6fc5f25619..e170682dae78 100644
--- a/drivers/media/v4l2-core/v4l2-async.c
+++ b/drivers/media/v4l2-core/v4l2-async.c
@@ -25,6 +25,34 @@
 #include <media/v4l2-fwnode.h>
 #include <media/v4l2-subdev.h>
 
+static int v4l2_async_notifier_call_bound(struct v4l2_async_notifier *n,
+					  struct v4l2_subdev *subdev,
+					  struct v4l2_async_subdev *asd)
+{
+	if (!n->ops || !n->ops->bound)
+		return 0;
+
+	return n->ops->bound(n, subdev, asd);
+}
+
+static void v4l2_async_notifier_call_unbind(struct v4l2_async_notifier *n,
+					    struct v4l2_subdev *subdev,
+					    struct v4l2_async_subdev *asd)
+{
+	if (!n->ops || !n->ops->unbind)
+		return;
+
+	n->ops->unbind(n, subdev, asd);
+}
+
+static int v4l2_async_notifier_call_complete(struct v4l2_async_notifier *n)
+{
+	if (!n->ops || !n->ops->complete)
+		return 0;
+
+	return n->ops->complete(n);
+}
+
 static bool match_i2c(struct v4l2_subdev *sd, struct v4l2_async_subdev *asd)
 {
 #if IS_ENABLED(CONFIG_I2C)
@@ -102,16 +130,13 @@ static int v4l2_async_match_notify(struct v4l2_async_notifier *notifier,
 {
 	int ret;
 
-	if (notifier->ops->bound) {
-		ret = notifier->ops->bound(notifier, sd, asd);
-		if (ret < 0)
-			return ret;
-	}
+	ret = v4l2_async_notifier_call_bound(notifier, sd, asd);
+	if (ret < 0)
+		return ret;
 
 	ret = v4l2_device_register_subdev(notifier->v4l2_dev, sd);
 	if (ret < 0) {
-		if (notifier->ops->unbind)
-			notifier->ops->unbind(notifier, sd, asd);
+		v4l2_async_notifier_call_unbind(notifier, sd, asd);
 		return ret;
 	}
 
@@ -140,8 +165,7 @@ static void v4l2_async_notifier_unbind_all_subdevs(
 	struct v4l2_subdev *sd, *tmp;
 
 	list_for_each_entry_safe(sd, tmp, &notifier->done, async_list) {
-		if (notifier->ops->unbind)
-			notifier->ops->unbind(notifier, sd, sd->asd);
+		v4l2_async_notifier_call_unbind(notifier, sd, sd->asd);
 		v4l2_async_cleanup(sd);
 
 		list_move(&sd->async_list, &subdev_list);
@@ -198,8 +222,8 @@ int v4l2_async_notifier_register(struct v4l2_device *v4l2_dev,
 		}
 	}
 
-	if (list_empty(&notifier->waiting) && notifier->ops->complete) {
-		ret = notifier->ops->complete(notifier);
+	if (list_empty(&notifier->waiting)) {
+		ret = v4l2_async_notifier_call_complete(notifier);
 		if (ret)
 			goto err_complete;
 	}
@@ -296,10 +320,10 @@ int v4l2_async_register_subdev(struct v4l2_subdev *sd)
 		if (ret)
 			goto err_unlock;
 
-		if (!list_empty(&notifier->waiting) || !notifier->ops->complete)
+		if (!list_empty(&notifier->waiting))
 			goto out_unlock;
 
-		ret = notifier->ops->complete(notifier);
+		ret = v4l2_async_notifier_call_complete(notifier);
 		if (ret)
 			goto err_cleanup;
 
@@ -315,8 +339,7 @@ int v4l2_async_register_subdev(struct v4l2_subdev *sd)
 	return 0;
 
 err_cleanup:
-	if (notifier->ops->unbind)
-		notifier->ops->unbind(notifier, sd, sd->asd);
+	v4l2_async_notifier_call_unbind(notifier, sd, sd->asd);
 	v4l2_async_cleanup(sd);
 
 err_unlock:
@@ -335,8 +358,7 @@ void v4l2_async_unregister_subdev(struct v4l2_subdev *sd)
 
 		list_add(&sd->asd->list, &notifier->waiting);
 
-		if (notifier->ops->unbind)
-			notifier->ops->unbind(notifier, sd, sd->asd);
+		v4l2_async_notifier_call_unbind(notifier, sd, sd->asd);
 	}
 
 	v4l2_async_cleanup(sd);
-- 
2.11.0

[PATCH v15 15/32] v4l: async: Register sub-devices before calling bound callback

[Sakari Ailus]

Register the sub-device before calling the notifier's bound callback.
Doing this the other way around is problematic as the struct v4l2_device
has not assigned for the sub-device yet and may be required by the bound
callback.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
---
 drivers/media/v4l2-core/v4l2-async.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/media/v4l2-core/v4l2-async.c b/drivers/media/v4l2-core/v4l2-async.c
index e170682dae78..46db85685894 100644
--- a/drivers/media/v4l2-core/v4l2-async.c
+++ b/drivers/media/v4l2-core/v4l2-async.c
@@ -130,13 +130,13 @@ static int v4l2_async_match_notify(struct v4l2_async_notifier *notifier,
 {
 	int ret;
 
-	ret = v4l2_async_notifier_call_bound(notifier, sd, asd);
+	ret = v4l2_device_register_subdev(notifier->v4l2_dev, sd);
 	if (ret < 0)
 		return ret;
 
-	ret = v4l2_device_register_subdev(notifier->v4l2_dev, sd);
+	ret = v4l2_async_notifier_call_bound(notifier, sd, asd);
 	if (ret < 0) {
-		v4l2_async_notifier_call_unbind(notifier, sd, asd);
+		v4l2_device_unregister_subdev(sd);
 		return ret;
 	}
 
-- 
2.11.0

[PATCH v15 16/32] v4l: async: Allow async notifier register call succeed with no subdevs

[Sakari Ailus]

The information on how many async sub-devices would be bindable to a
notifier is typically dependent on information from platform firmware and
it's not driver's business to be aware of that.

Many V4L2 main drivers are perfectly usable (and useful) without async
sub-devices and so if there aren't any around, just proceed call the
notifier's complete callback immediately without registering the notifier
itself.

If a driver needs to check whether there are async sub-devices available,
it can be done by inspecting the notifier's num_subdevs field which tells
the number of async sub-devices.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
---
 drivers/media/v4l2-core/v4l2-async.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/drivers/media/v4l2-core/v4l2-async.c b/drivers/media/v4l2-core/v4l2-async.c
index 46db85685894..1b536d68cedf 100644
--- a/drivers/media/v4l2-core/v4l2-async.c
+++ b/drivers/media/v4l2-core/v4l2-async.c
@@ -180,14 +180,22 @@ int v4l2_async_notifier_register(struct v4l2_device *v4l2_dev,
 	int ret;
 	int i;
 
-	if (!v4l2_dev || !notifier->num_subdevs ||
-	    notifier->num_subdevs > V4L2_MAX_SUBDEVS)
+	if (!v4l2_dev || notifier->num_subdevs > V4L2_MAX_SUBDEVS)
 		return -EINVAL;
 
 	notifier->v4l2_dev = v4l2_dev;
 	INIT_LIST_HEAD(&notifier->waiting);
 	INIT_LIST_HEAD(&notifier->done);
 
+	if (!notifier->num_subdevs) {
+		int ret;
+
+		ret = v4l2_async_notifier_call_complete(notifier);
+		notifier->v4l2_dev = NULL;
+
+		return ret;
+	}
+
 	for (i = 0; i < notifier->num_subdevs; i++) {
 		asd = notifier->subdevs[i];
 
-- 
2.11.0

[PATCH v15 17/32] v4l: async: Prepare for async sub-device notifiers

[Sakari Ailus]

Refactor the V4L2 async framework a little in preparation for async
sub-device notifiers. This avoids making some structural changes in the
patch actually implementing sub-device notifiers, making that patch easier
to review.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
---
 drivers/media/v4l2-core/v4l2-async.c | 70 ++++++++++++++++++++++++++----------
 1 file changed, 51 insertions(+), 19 deletions(-)

diff --git a/drivers/media/v4l2-core/v4l2-async.c b/drivers/media/v4l2-core/v4l2-async.c
index 1b536d68cedf..1812310746d9 100644
--- a/drivers/media/v4l2-core/v4l2-async.c
+++ b/drivers/media/v4l2-core/v4l2-async.c
@@ -125,12 +125,13 @@ static struct v4l2_async_subdev *v4l2_async_find_match(
 }
 
 static int v4l2_async_match_notify(struct v4l2_async_notifier *notifier,
+				   struct v4l2_device *v4l2_dev,
 				   struct v4l2_subdev *sd,
 				   struct v4l2_async_subdev *asd)
 {
 	int ret;
 
-	ret = v4l2_device_register_subdev(notifier->v4l2_dev, sd);
+	ret = v4l2_device_register_subdev(v4l2_dev, sd);
 	if (ret < 0)
 		return ret;
 
@@ -151,6 +152,31 @@ static int v4l2_async_match_notify(struct v4l2_async_notifier *notifier,
 	return 0;
 }
 
+/* Test all async sub-devices in a notifier for a match. */
+static int v4l2_async_notifier_try_all_subdevs(
+	struct v4l2_async_notifier *notifier)
+{
+	struct v4l2_device *v4l2_dev = notifier->v4l2_dev;
+	struct v4l2_subdev *sd, *tmp;
+
+	list_for_each_entry_safe(sd, tmp, &subdev_list, async_list) {
+		struct v4l2_async_subdev *asd;
+		int ret;
+
+		asd = v4l2_async_find_match(notifier, sd);
+		if (!asd)
+			continue;
+
+		ret = v4l2_async_match_notify(notifier, v4l2_dev, sd, asd);
+		if (ret < 0) {
+			mutex_unlock(&list_lock);
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
 static void v4l2_async_cleanup(struct v4l2_subdev *sd)
 {
 	v4l2_device_unregister_subdev(sd);
@@ -172,18 +198,15 @@ static void v4l2_async_notifier_unbind_all_subdevs(
 	}
 }
 
-int v4l2_async_notifier_register(struct v4l2_device *v4l2_dev,
-				 struct v4l2_async_notifier *notifier)
+static int __v4l2_async_notifier_register(struct v4l2_async_notifier *notifier)
 {
-	struct v4l2_subdev *sd, *tmp;
 	struct v4l2_async_subdev *asd;
 	int ret;
 	int i;
 
-	if (!v4l2_dev || notifier->num_subdevs > V4L2_MAX_SUBDEVS)
+	if (notifier->num_subdevs > V4L2_MAX_SUBDEVS)
 		return -EINVAL;
 
-	notifier->v4l2_dev = v4l2_dev;
 	INIT_LIST_HEAD(&notifier->waiting);
 	INIT_LIST_HEAD(&notifier->done);
 
@@ -216,18 +239,10 @@ int v4l2_async_notifier_register(struct v4l2_device *v4l2_dev,
 
 	mutex_lock(&list_lock);
 
-	list_for_each_entry_safe(sd, tmp, &subdev_list, async_list) {
-		int ret;
-
-		asd = v4l2_async_find_match(notifier, sd);
-		if (!asd)
-			continue;
-
-		ret = v4l2_async_match_notify(notifier, sd, asd);
-		if (ret < 0) {
-			mutex_unlock(&list_lock);
-			return ret;
-		}
+	ret = v4l2_async_notifier_try_all_subdevs(notifier);
+	if (ret) {
+		mutex_unlock(&list_lock);
+		return ret;
 	}
 
 	if (list_empty(&notifier->waiting)) {
@@ -250,6 +265,22 @@ int v4l2_async_notifier_register(struct v4l2_device *v4l2_dev,
 
 	return ret;
 }
+
+int v4l2_async_notifier_register(struct v4l2_device *v4l2_dev,
+				 struct v4l2_async_notifier *notifier)
+{
+	int ret;
+	if (WARN_ON(!v4l2_dev))
+		return -EINVAL;
+
+	notifier->v4l2_dev = v4l2_dev;
+
+	ret = __v4l2_async_notifier_register(notifier);
+	if (ret)
+		notifier->v4l2_dev = NULL;
+
+	return ret;
+}
 EXPORT_SYMBOL(v4l2_async_notifier_register);
 
 void v4l2_async_notifier_unregister(struct v4l2_async_notifier *notifier)
@@ -324,7 +355,8 @@ int v4l2_async_register_subdev(struct v4l2_subdev *sd)
 		if (!asd)
 			continue;
 
-		ret = v4l2_async_match_notify(notifier, sd, asd);
+		ret = v4l2_async_match_notify(notifier, notifier->v4l2_dev, sd,
+					      asd);
 		if (ret)
 			goto err_unlock;
 
-- 
2.11.0

[PATCH v15 18/32] v4l: async: Allow binding notifiers to sub-devices

[Sakari Ailus]

Registering a notifier has required the knowledge of struct v4l2_device
for the reason that sub-devices generally are registered to the
v4l2_device (as well as the media device, also available through
v4l2_device).

This information is not available for sub-device drivers at probe time.

What this patch does is that it allows registering notifiers without
having v4l2_device around. Instead the sub-device pointer is stored in the
notifier. Once the sub-device of the driver that registered the notifier
is registered, the notifier will gain the knowledge of the v4l2_device,
and the binding of async sub-devices from the sub-device driver's notifier
may proceed.

The complete callbacks will be called only when the v4l2_device is
available and no notifier has pending sub-devices to bind.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
---
 drivers/media/v4l2-core/v4l2-async.c | 239 ++++++++++++++++++++++++++++-------
 include/media/v4l2-async.h           |  16 ++-
 2 files changed, 211 insertions(+), 44 deletions(-)

diff --git a/drivers/media/v4l2-core/v4l2-async.c b/drivers/media/v4l2-core/v4l2-async.c
index 1812310746d9..3621ed6e6e3c 100644
--- a/drivers/media/v4l2-core/v4l2-async.c
+++ b/drivers/media/v4l2-core/v4l2-async.c
@@ -124,11 +124,109 @@ static struct v4l2_async_subdev *v4l2_async_find_match(
 	return NULL;
 }
 
+/* Find the sub-device notifier registered by a sub-device driver. */
+static struct v4l2_async_notifier *v4l2_async_find_subdev_notifier(
+	struct v4l2_subdev *sd)
+{
+	struct v4l2_async_notifier *n;
+
+	list_for_each_entry(n, &notifier_list, list)
+		if (n->sd == sd)
+			return n;
+
+	return NULL;
+}
+
+/* Get v4l2_device related to the notifier if one can be found. */
+static struct v4l2_device *v4l2_async_notifier_find_v4l2_dev(
+	struct v4l2_async_notifier *notifier)
+{
+	while (notifier->parent)
+		notifier = notifier->parent;
+
+	return notifier->v4l2_dev;
+}
+
+/*
+ * Return true if all child sub-device notifiers are complete, false otherwise.
+ */
+static bool v4l2_async_notifier_can_complete(
+	struct v4l2_async_notifier *notifier)
+{
+	struct v4l2_subdev *sd;
+
+	if (!list_empty(&notifier->waiting))
+		return false;
+
+	list_for_each_entry(sd, &notifier->done, async_list) {
+		struct v4l2_async_notifier *subdev_notifier =
+			v4l2_async_find_subdev_notifier(sd);
+
+		if (subdev_notifier &&
+		    !v4l2_async_notifier_can_complete(subdev_notifier))
+			return false;
+	}
+
+	return true;
+}
+
+/* Complete all notifiers. Call on the root notifier. */
+static int v4l2_async_notifier_complete(
+	struct v4l2_async_notifier *notifier)
+{
+	struct v4l2_subdev *sd;
+
+	list_for_each_entry(sd, &notifier->done, async_list) {
+		struct v4l2_async_notifier *subdev_notifier =
+			v4l2_async_find_subdev_notifier(sd);
+		int ret;
+
+		if (!subdev_notifier)
+			continue;
+
+		ret = v4l2_async_notifier_complete(subdev_notifier);
+		if (ret)
+			return ret;
+	}
+
+	return v4l2_async_notifier_call_complete(notifier);
+}
+
+/*
+ * Complete notifiers if possible. This is done when all async sub-devices have
+ * been bound; v4l2_device is also available then.
+ */
+static int v4l2_async_notifier_try_complete(
+	struct v4l2_async_notifier *notifier)
+{
+	/* Quick check whether there are still more sub-devices here. */
+	if (!list_empty(&notifier->waiting))
+		return 0;
+
+	/* Check the entire notifier tree; find the root notifier first. */
+	while (notifier->parent)
+		notifier = notifier->parent;
+
+	/* This is root if it has v4l2_dev. */
+	if (!notifier->v4l2_dev)
+		return 0;
+
+	/* Is everything ready? */
+	if (!v4l2_async_notifier_can_complete(notifier))
+		return 0;
+
+	return v4l2_async_notifier_complete(notifier);
+}
+
+static int v4l2_async_notifier_try_all_subdevs(
+	struct v4l2_async_notifier *notifier);
+
 static int v4l2_async_match_notify(struct v4l2_async_notifier *notifier,
 				   struct v4l2_device *v4l2_dev,
 				   struct v4l2_subdev *sd,
 				   struct v4l2_async_subdev *asd)
 {
+	struct v4l2_async_notifier *subdev_notifier;
 	int ret;
 
 	ret = v4l2_device_register_subdev(v4l2_dev, sd);
@@ -149,17 +247,36 @@ static int v4l2_async_match_notify(struct v4l2_async_notifier *notifier,
 	/* Move from the global subdevice list to notifier's done */
 	list_move(&sd->async_list, &notifier->done);
 
-	return 0;
+	/*
+	 * See if the sub-device has a notifier. If not, return here.
+	 */
+	subdev_notifier = v4l2_async_find_subdev_notifier(sd);
+	if (!subdev_notifier || subdev_notifier->parent)
+		return 0;
+
+	/*
+	 * Proceed with checking for the sub-device notifier's async
+	 * sub-devices, and return the result. The error will be handled by the
+	 * caller.
+	 */
+	subdev_notifier->parent = notifier;
+
+	return v4l2_async_notifier_try_all_subdevs(subdev_notifier);
 }
 
 /* Test all async sub-devices in a notifier for a match. */
 static int v4l2_async_notifier_try_all_subdevs(
 	struct v4l2_async_notifier *notifier)
 {
-	struct v4l2_device *v4l2_dev = notifier->v4l2_dev;
-	struct v4l2_subdev *sd, *tmp;
+	struct v4l2_device *v4l2_dev =
+		v4l2_async_notifier_find_v4l2_dev(notifier);
+	struct v4l2_subdev *sd;
 
-	list_for_each_entry_safe(sd, tmp, &subdev_list, async_list) {
+	if (!v4l2_dev)
+		return 0;
+
+again:
+	list_for_each_entry(sd, &subdev_list, async_list) {
 		struct v4l2_async_subdev *asd;
 		int ret;
 
@@ -168,10 +285,16 @@ static int v4l2_async_notifier_try_all_subdevs(
 			continue;
 
 		ret = v4l2_async_match_notify(notifier, v4l2_dev, sd, asd);
-		if (ret < 0) {
-			mutex_unlock(&list_lock);
+		if (ret < 0)
 			return ret;
-		}
+
+		/*
+		 * v4l2_async_match_notify() may lead to registering a
+		 * new notifier and thus changing the async subdevs
+		 * list. In order to proceed safely from here, restart
+		 * parsing the list from the beginning.
+		 */
+		goto again;
 	}
 
 	return 0;
@@ -185,17 +308,26 @@ static void v4l2_async_cleanup(struct v4l2_subdev *sd)
 	sd->asd = NULL;
 }
 
+/* Unbind all sub-devices in the notifier tree. */
 static void v4l2_async_notifier_unbind_all_subdevs(
 	struct v4l2_async_notifier *notifier)
 {
 	struct v4l2_subdev *sd, *tmp;
 
 	list_for_each_entry_safe(sd, tmp, &notifier->done, async_list) {
+		struct v4l2_async_notifier *subdev_notifier =
+			v4l2_async_find_subdev_notifier(sd);
+
+		if (subdev_notifier)
+			v4l2_async_notifier_unbind_all_subdevs(subdev_notifier);
+
 		v4l2_async_notifier_call_unbind(notifier, sd, sd->asd);
 		v4l2_async_cleanup(sd);
 
 		list_move(&sd->async_list, &subdev_list);
 	}
+
+	notifier->parent = NULL;
 }
 
 static int __v4l2_async_notifier_register(struct v4l2_async_notifier *notifier)
@@ -210,15 +342,6 @@ static int __v4l2_async_notifier_register(struct v4l2_async_notifier *notifier)
 	INIT_LIST_HEAD(&notifier->waiting);
 	INIT_LIST_HEAD(&notifier->done);
 
-	if (!notifier->num_subdevs) {
-		int ret;
-
-		ret = v4l2_async_notifier_call_complete(notifier);
-		notifier->v4l2_dev = NULL;
-
-		return ret;
-	}
-
 	for (i = 0; i < notifier->num_subdevs; i++) {
 		asd = notifier->subdevs[i];
 
@@ -240,16 +363,12 @@ static int __v4l2_async_notifier_register(struct v4l2_async_notifier *notifier)
 	mutex_lock(&list_lock);
 
 	ret = v4l2_async_notifier_try_all_subdevs(notifier);
-	if (ret) {
-		mutex_unlock(&list_lock);
-		return ret;
-	}
+	if (ret)
+		goto err_unbind;
 
-	if (list_empty(&notifier->waiting)) {
-		ret = v4l2_async_notifier_call_complete(notifier);
-		if (ret)
-			goto err_complete;
-	}
+	ret = v4l2_async_notifier_try_complete(notifier);
+	if (ret)
+		goto err_unbind;
 
 	/* Keep also completed notifiers on the list */
 	list_add(&notifier->list, &notifier_list);
@@ -258,7 +377,10 @@ static int __v4l2_async_notifier_register(struct v4l2_async_notifier *notifier)
 
 	return 0;
 
-err_complete:
+err_unbind:
+	/*
+	 * On failure, unbind all sub-devices registered through this notifier.
+	 */
 	v4l2_async_notifier_unbind_all_subdevs(notifier);
 
 	mutex_unlock(&list_lock);
@@ -270,7 +392,8 @@ int v4l2_async_notifier_register(struct v4l2_device *v4l2_dev,
 				 struct v4l2_async_notifier *notifier)
 {
 	int ret;
-	if (WARN_ON(!v4l2_dev))
+
+	if (WARN_ON(!v4l2_dev || notifier->sd))
 		return -EINVAL;
 
 	notifier->v4l2_dev = v4l2_dev;
@@ -283,20 +406,39 @@ int v4l2_async_notifier_register(struct v4l2_device *v4l2_dev,
 }
 EXPORT_SYMBOL(v4l2_async_notifier_register);
 
+int v4l2_async_subdev_notifier_register(struct v4l2_subdev *sd,
+					struct v4l2_async_notifier *notifier)
+{
+	int ret;
+
+	if (WARN_ON(!sd || notifier->v4l2_dev))
+		return -EINVAL;
+
+	notifier->sd = sd;
+
+	ret = __v4l2_async_notifier_register(notifier);
+	if (ret)
+		notifier->sd = NULL;
+
+	return ret;
+}
+EXPORT_SYMBOL(v4l2_async_subdev_notifier_register);
+
 void v4l2_async_notifier_unregister(struct v4l2_async_notifier *notifier)
 {
-	if (!notifier->v4l2_dev)
+	if (!notifier->v4l2_dev && !notifier->sd)
 		return;
 
 	mutex_lock(&list_lock);
 
-	list_del(&notifier->list);
-
 	v4l2_async_notifier_unbind_all_subdevs(notifier);
 
-	mutex_unlock(&list_lock);
-
+	notifier->sd = NULL;
 	notifier->v4l2_dev = NULL;
+
+	list_del(&notifier->list);
+
+	mutex_unlock(&list_lock);
 }
 EXPORT_SYMBOL(v4l2_async_notifier_unregister);
 
@@ -332,6 +474,7 @@ EXPORT_SYMBOL_GPL(v4l2_async_notifier_cleanup);
 
 int v4l2_async_register_subdev(struct v4l2_subdev *sd)
 {
+	struct v4l2_async_notifier *subdev_notifier;
 	struct v4l2_async_notifier *notifier;
 	int ret;
 
@@ -348,24 +491,26 @@ int v4l2_async_register_subdev(struct v4l2_subdev *sd)
 	INIT_LIST_HEAD(&sd->async_list);
 
 	list_for_each_entry(notifier, &notifier_list, list) {
-		struct v4l2_async_subdev *asd = v4l2_async_find_match(notifier,
-								      sd);
+		struct v4l2_device *v4l2_dev =
+			v4l2_async_notifier_find_v4l2_dev(notifier);
+		struct v4l2_async_subdev *asd;
 		int ret;
 
+		if (!v4l2_dev)
+			continue;
+
+		asd = v4l2_async_find_match(notifier, sd);
 		if (!asd)
 			continue;
 
 		ret = v4l2_async_match_notify(notifier, notifier->v4l2_dev, sd,
 					      asd);
 		if (ret)
-			goto err_unlock;
+			goto err_unbind;
 
-		if (!list_empty(&notifier->waiting))
-			goto out_unlock;
-
-		ret = v4l2_async_notifier_call_complete(notifier);
+		ret = v4l2_async_notifier_try_complete(notifier);
 		if (ret)
-			goto err_cleanup;
+			goto err_unbind;
 
 		goto out_unlock;
 	}
@@ -378,11 +523,19 @@ int v4l2_async_register_subdev(struct v4l2_subdev *sd)
 
 	return 0;
 
-err_cleanup:
-	v4l2_async_notifier_call_unbind(notifier, sd, sd->asd);
+err_unbind:
+	/*
+	 * Complete failed. Unbind the sub-devices bound through registering
+	 * this async sub-device.
+	 */
+	subdev_notifier = v4l2_async_find_subdev_notifier(sd);
+	if (subdev_notifier)
+		v4l2_async_notifier_unbind_all_subdevs(subdev_notifier);
+
+	if (sd->asd)
+		v4l2_async_notifier_call_unbind(notifier, sd, sd->asd);
 	v4l2_async_cleanup(sd);
 
-err_unlock:
 	mutex_unlock(&list_lock);
 
 	return ret;
diff --git a/include/media/v4l2-async.h b/include/media/v4l2-async.h
index 68606afb5ef9..d33a52be2501 100644
--- a/include/media/v4l2-async.h
+++ b/include/media/v4l2-async.h
@@ -102,7 +102,9 @@ struct v4l2_async_notifier_operations {
  * @num_subdevs: number of subdevices used in the subdevs array
  * @max_subdevs: number of subdevices allocated in the subdevs array
  * @subdevs:	array of pointers to subdevice descriptors
- * @v4l2_dev:	pointer to struct v4l2_device
+ * @v4l2_dev:	v4l2_device of the root notifier, NULL otherwise
+ * @sd:		sub-device that registered the notifier, NULL otherwise
+ * @parent:	parent notifier
  * @waiting:	list of struct v4l2_async_subdev, waiting for their drivers
  * @done:	list of struct v4l2_subdev, already probed
  * @list:	member in a global list of notifiers
@@ -113,6 +115,8 @@ struct v4l2_async_notifier {
 	unsigned int max_subdevs;
 	struct v4l2_async_subdev **subdevs;
 	struct v4l2_device *v4l2_dev;
+	struct v4l2_subdev *sd;
+	struct v4l2_async_notifier *parent;
 	struct list_head waiting;
 	struct list_head done;
 	struct list_head list;
@@ -128,6 +132,16 @@ int v4l2_async_notifier_register(struct v4l2_device *v4l2_dev,
 				 struct v4l2_async_notifier *notifier);
 
 /**
+ * v4l2_async_subdev_notifier_register - registers a subdevice asynchronous
+ *					 notifier for a sub-device
+ *
+ * @sd: pointer to &struct v4l2_subdev
+ * @notifier: pointer to &struct v4l2_async_notifier
+ */
+int v4l2_async_subdev_notifier_register(struct v4l2_subdev *sd,
+					struct v4l2_async_notifier *notifier);
+
+/**
  * v4l2_async_notifier_unregister - unregisters a subdevice asynchronous notifier
  *
  * @notifier: pointer to &struct v4l2_async_notifier
-- 
2.11.0

[PATCH v15 19/32] v4l: async: Ensure only unique fwnodes are registered to notifiers

[Sakari Ailus]

While registering a notifier, check that each newly added fwnode is
unique, and return an error if it is not. Also check that a newly added
notifier does not have the same fwnodes twice.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
---
 drivers/media/v4l2-core/v4l2-async.c | 82 +++++++++++++++++++++++++++++++++---
 1 file changed, 77 insertions(+), 5 deletions(-)

diff --git a/drivers/media/v4l2-core/v4l2-async.c b/drivers/media/v4l2-core/v4l2-async.c
index 3621ed6e6e3c..e1fe3567127a 100644
--- a/drivers/media/v4l2-core/v4l2-async.c
+++ b/drivers/media/v4l2-core/v4l2-async.c
@@ -330,8 +330,71 @@ static void v4l2_async_notifier_unbind_all_subdevs(
 	notifier->parent = NULL;
 }
 
+/* See if an fwnode can be found in a notifier's lists. */
+static bool __v4l2_async_notifier_fwnode_has_async_subdev(
+	struct v4l2_async_notifier *notifier, struct fwnode_handle *fwnode)
+{
+	struct v4l2_async_subdev *asd;
+	struct v4l2_subdev *sd;
+
+	list_for_each_entry(asd, &notifier->waiting, list) {
+		if (asd->match_type != V4L2_ASYNC_MATCH_FWNODE)
+			continue;
+
+		if (asd->match.fwnode.fwnode == fwnode)
+			return true;
+	}
+
+	list_for_each_entry(sd, &notifier->done, async_list) {
+		if (WARN_ON(!sd->asd))
+			continue;
+
+		if (sd->asd->match_type != V4L2_ASYNC_MATCH_FWNODE)
+			continue;
+
+		if (sd->asd->match.fwnode.fwnode == fwnode)
+			return true;
+	}
+
+	return false;
+}
+
+/*
+ * Find out whether an async sub-device was set up for an fwnode already or
+ * whether it exists in a given notifier before @this_index.
+ */
+static bool v4l2_async_notifier_fwnode_has_async_subdev(
+	struct v4l2_async_notifier *notifier, struct fwnode_handle *fwnode,
+	unsigned int this_index)
+{
+	unsigned int j;
+
+	lockdep_assert_held(&list_lock);
+
+	/* Check that an fwnode is not being added more than once. */
+	for (j = 0; j < this_index; j++) {
+		struct v4l2_async_subdev *asd = notifier->subdevs[this_index];
+		struct v4l2_async_subdev *other_asd = notifier->subdevs[j];
+
+		if (other_asd->match_type == V4L2_ASYNC_MATCH_FWNODE &&
+		    asd->match.fwnode.fwnode ==
+		    other_asd->match.fwnode.fwnode)
+			return true;
+	}
+
+	/* Check than an fwnode did not exist in other notifiers. */
+	list_for_each_entry(notifier, &notifier_list, list)
+		if (__v4l2_async_notifier_fwnode_has_async_subdev(
+			    notifier, fwnode))
+			return true;
+
+	return false;
+}
+
 static int __v4l2_async_notifier_register(struct v4l2_async_notifier *notifier)
 {
+	struct device *dev =
+		notifier->v4l2_dev ? notifier->v4l2_dev->dev : NULL;
 	struct v4l2_async_subdev *asd;
 	int ret;
 	int i;
@@ -342,6 +405,8 @@ static int __v4l2_async_notifier_register(struct v4l2_async_notifier *notifier)
 	INIT_LIST_HEAD(&notifier->waiting);
 	INIT_LIST_HEAD(&notifier->done);
 
+	mutex_lock(&list_lock);
+
 	for (i = 0; i < notifier->num_subdevs; i++) {
 		asd = notifier->subdevs[i];
 
@@ -349,19 +414,25 @@ static int __v4l2_async_notifier_register(struct v4l2_async_notifier *notifier)
 		case V4L2_ASYNC_MATCH_CUSTOM:
 		case V4L2_ASYNC_MATCH_DEVNAME:
 		case V4L2_ASYNC_MATCH_I2C:
+			break;
 		case V4L2_ASYNC_MATCH_FWNODE:
+			if (v4l2_async_notifier_fwnode_has_async_subdev(
+				    notifier, asd->match.fwnode.fwnode, i)) {
+				dev_err(dev,
+					"fwnode has already been registered or in notifier's subdev list\n");
+				ret = -EEXIST;
+				goto out_unlock;
+			}
 			break;
 		default:
-			dev_err(notifier->v4l2_dev ? notifier->v4l2_dev->dev : NULL,
-				"Invalid match type %u on %p\n",
+			dev_err(dev, "Invalid match type %u on %p\n",
 				asd->match_type, asd);
-			return -EINVAL;
+			ret = -EINVAL;
+			goto out_unlock;
 		}
 		list_add_tail(&asd->list, &notifier->waiting);
 	}
 
-	mutex_lock(&list_lock);
-
 	ret = v4l2_async_notifier_try_all_subdevs(notifier);
 	if (ret)
 		goto err_unbind;
@@ -373,6 +444,7 @@ static int __v4l2_async_notifier_register(struct v4l2_async_notifier *notifier)
 	/* Keep also completed notifiers on the list */
 	list_add(&notifier->list, &notifier_list);
 
+out_unlock:
 	mutex_unlock(&list_lock);
 
 	return 0;
-- 
2.11.0

[PATCH v15 20/32] dt: bindings: Add a binding for flash LED devices associated to a sensor

[Sakari Ailus]

Camera flash drivers (and LEDs) are separate from the sensor devices in
DT. In order to make an association between the two, provide the
association information to the software.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Cc: Rob Herring <robh@kernel.org>
Cc: devicetree@vger.kernel.org
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
---
 Documentation/devicetree/bindings/media/video-interfaces.txt | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/Documentation/devicetree/bindings/media/video-interfaces.txt b/Documentation/devicetree/bindings/media/video-interfaces.txt
index 852041a7480c..fdba30479b47 100644
--- a/Documentation/devicetree/bindings/media/video-interfaces.txt
+++ b/Documentation/devicetree/bindings/media/video-interfaces.txt
@@ -67,6 +67,14 @@ are required in a relevant parent node:
 		    identifier, should be 1.
  - #size-cells    : should be zero.
 
+
+Optional properties
+-------------------
+
+- flash-leds: An array of phandles, each referring to a flash LED, a sub-node
+  of the LED driver device node.
+
+
 Optional endpoint properties
 ----------------------------
 
-- 
2.11.0

[PATCH v15 21/32] dt: bindings: Add lens-focus binding for image sensors

[Sakari Ailus]

The lens-focus property contains a phandle to the lens voice coil driver
that is associated to the sensor; typically both are contained in the same
camera module.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Cc: Rob Herring <robh@kernel.org>
Cc: devicetree@vger.kernel.org
Acked-by: Pavel Machek <pavel@ucw.cz>
Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>
Acked-by: Rob Herring <robh@kernel.org>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
---
 Documentation/devicetree/bindings/media/video-interfaces.txt | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/Documentation/devicetree/bindings/media/video-interfaces.txt b/Documentation/devicetree/bindings/media/video-interfaces.txt
index fdba30479b47..b535bdde861c 100644
--- a/Documentation/devicetree/bindings/media/video-interfaces.txt
+++ b/Documentation/devicetree/bindings/media/video-interfaces.txt
@@ -74,6 +74,8 @@ Optional properties
 - flash-leds: An array of phandles, each referring to a flash LED, a sub-node
   of the LED driver device node.
 
+- lens-focus: A phandle to the node of the focus lens controller.
+
 
 Optional endpoint properties
 ----------------------------
-- 
2.11.0

[PATCH v15 22/32] v4l: fwnode: Move KernelDoc documentation to the header

[Sakari Ailus]

In V4L2 the practice is to have the KernelDoc documentation in the header
and not in .c source code files. This consequently makes the V4L2 fwnode
function documentation part of the Media documentation build.

Also correct the link related function and argument naming in
documentation and add an asterisk to v4l2_fwnode_endpoint_free()
documentation to make it proper KernelDoc documentation.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
---
 drivers/media/v4l2-core/v4l2-fwnode.c | 75 --------------------------------
 include/media/v4l2-fwnode.h           | 81 ++++++++++++++++++++++++++++++++++-
 2 files changed, 80 insertions(+), 76 deletions(-)

diff --git a/drivers/media/v4l2-core/v4l2-fwnode.c b/drivers/media/v4l2-core/v4l2-fwnode.c
index df0695b7bbcc..65bdcd59744a 100644
--- a/drivers/media/v4l2-core/v4l2-fwnode.c
+++ b/drivers/media/v4l2-core/v4l2-fwnode.c
@@ -183,25 +183,6 @@ v4l2_fwnode_endpoint_parse_csi1_bus(struct fwnode_handle *fwnode,
 		vep->bus_type = V4L2_MBUS_CSI1;
 }
 
-/**
- * v4l2_fwnode_endpoint_parse() - parse all fwnode node properties
- * @fwnode: pointer to the endpoint's fwnode handle
- * @vep: pointer to the V4L2 fwnode data structure
- *
- * All properties are optional. If none are found, we don't set any flags. This
- * means the port has a static configuration and no properties have to be
- * specified explicitly. If any properties that identify the bus as parallel
- * are found and slave-mode isn't set, we set V4L2_MBUS_MASTER. Similarly, if
- * we recognise the bus as serial CSI-2 and clock-noncontinuous isn't set, we
- * set the V4L2_MBUS_CSI2_CONTINUOUS_CLOCK flag. The caller should hold a
- * reference to @fwnode.
- *
- * NOTE: This function does not parse properties the size of which is variable
- * without a low fixed limit. Please use v4l2_fwnode_endpoint_alloc_parse() in
- * new drivers instead.
- *
- * Return: 0 on success or a negative error code on failure.
- */
 int v4l2_fwnode_endpoint_parse(struct fwnode_handle *fwnode,
 			       struct v4l2_fwnode_endpoint *vep)
 {
@@ -241,14 +222,6 @@ int v4l2_fwnode_endpoint_parse(struct fwnode_handle *fwnode,
 }
 EXPORT_SYMBOL_GPL(v4l2_fwnode_endpoint_parse);
 
-/*
- * v4l2_fwnode_endpoint_free() - free the V4L2 fwnode acquired by
- * v4l2_fwnode_endpoint_alloc_parse()
- * @vep - the V4L2 fwnode the resources of which are to be released
- *
- * It is safe to call this function with NULL argument or on a V4L2 fwnode the
- * parsing of which failed.
- */
 void v4l2_fwnode_endpoint_free(struct v4l2_fwnode_endpoint *vep)
 {
 	if (IS_ERR_OR_NULL(vep))
@@ -259,29 +232,6 @@ void v4l2_fwnode_endpoint_free(struct v4l2_fwnode_endpoint *vep)
 }
 EXPORT_SYMBOL_GPL(v4l2_fwnode_endpoint_free);
 
-/**
- * v4l2_fwnode_endpoint_alloc_parse() - parse all fwnode node properties
- * @fwnode: pointer to the endpoint's fwnode handle
- *
- * All properties are optional. If none are found, we don't set any flags. This
- * means the port has a static configuration and no properties have to be
- * specified explicitly. If any properties that identify the bus as parallel
- * are found and slave-mode isn't set, we set V4L2_MBUS_MASTER. Similarly, if
- * we recognise the bus as serial CSI-2 and clock-noncontinuous isn't set, we
- * set the V4L2_MBUS_CSI2_CONTINUOUS_CLOCK flag. The caller should hold a
- * reference to @fwnode.
- *
- * v4l2_fwnode_endpoint_alloc_parse() has two important differences to
- * v4l2_fwnode_endpoint_parse():
- *
- * 1. It also parses variable size data.
- *
- * 2. The memory it has allocated to store the variable size data must be freed
- *    using v4l2_fwnode_endpoint_free() when no longer needed.
- *
- * Return: Pointer to v4l2_fwnode_endpoint if successful, on an error pointer
- * on error.
- */
 struct v4l2_fwnode_endpoint *v4l2_fwnode_endpoint_alloc_parse(
 	struct fwnode_handle *fwnode)
 {
@@ -324,24 +274,6 @@ struct v4l2_fwnode_endpoint *v4l2_fwnode_endpoint_alloc_parse(
 }
 EXPORT_SYMBOL_GPL(v4l2_fwnode_endpoint_alloc_parse);
 
-/**
- * v4l2_fwnode_endpoint_parse_link() - parse a link between two endpoints
- * @__fwnode: pointer to the endpoint's fwnode at the local end of the link
- * @link: pointer to the V4L2 fwnode link data structure
- *
- * Fill the link structure with the local and remote nodes and port numbers.
- * The local_node and remote_node fields are set to point to the local and
- * remote port's parent nodes respectively (the port parent node being the
- * parent node of the port node if that node isn't a 'ports' node, or the
- * grand-parent node of the port node otherwise).
- *
- * A reference is taken to both the local and remote nodes, the caller must use
- * v4l2_fwnode_endpoint_put_link() to drop the references when done with the
- * link.
- *
- * Return: 0 on success, or -ENOLINK if the remote endpoint fwnode can't be
- * found.
- */
 int v4l2_fwnode_parse_link(struct fwnode_handle *__fwnode,
 			   struct v4l2_fwnode_link *link)
 {
@@ -376,13 +308,6 @@ int v4l2_fwnode_parse_link(struct fwnode_handle *__fwnode,
 }
 EXPORT_SYMBOL_GPL(v4l2_fwnode_parse_link);
 
-/**
- * v4l2_fwnode_put_link() - drop references to nodes in a link
- * @link: pointer to the V4L2 fwnode link data structure
- *
- * Drop references to the local and remote nodes in the link. This function
- * must be called on every link parsed with v4l2_fwnode_parse_link().
- */
 void v4l2_fwnode_put_link(struct v4l2_fwnode_link *link)
 {
 	fwnode_handle_put(link->local_node);
diff --git a/include/media/v4l2-fwnode.h b/include/media/v4l2-fwnode.h
index ac605af9b877..671e76e2d285 100644
--- a/include/media/v4l2-fwnode.h
+++ b/include/media/v4l2-fwnode.h
@@ -115,13 +115,92 @@ struct v4l2_fwnode_link {
 	unsigned int remote_port;
 };
 
+/**
+ * v4l2_fwnode_endpoint_parse() - parse all fwnode node properties
+ * @fwnode: pointer to the endpoint's fwnode handle
+ * @vep: pointer to the V4L2 fwnode data structure
+ *
+ * All properties are optional. If none are found, we don't set any flags. This
+ * means the port has a static configuration and no properties have to be
+ * specified explicitly. If any properties that identify the bus as parallel
+ * are found and slave-mode isn't set, we set V4L2_MBUS_MASTER. Similarly, if
+ * we recognise the bus as serial CSI-2 and clock-noncontinuous isn't set, we
+ * set the V4L2_MBUS_CSI2_CONTINUOUS_CLOCK flag. The caller should hold a
+ * reference to @fwnode.
+ *
+ * NOTE: This function does not parse properties the size of which is variable
+ * without a low fixed limit. Please use v4l2_fwnode_endpoint_alloc_parse() in
+ * new drivers instead.
+ *
+ * Return: 0 on success or a negative error code on failure.
+ */
 int v4l2_fwnode_endpoint_parse(struct fwnode_handle *fwnode,
 			       struct v4l2_fwnode_endpoint *vep);
+
+/**
+ * v4l2_fwnode_endpoint_free() - free the V4L2 fwnode acquired by
+ * v4l2_fwnode_endpoint_alloc_parse()
+ * @vep - the V4L2 fwnode the resources of which are to be released
+ *
+ * It is safe to call this function with NULL argument or on a V4L2 fwnode the
+ * parsing of which failed.
+ */
+void v4l2_fwnode_endpoint_free(struct v4l2_fwnode_endpoint *vep);
+
+/**
+ * v4l2_fwnode_endpoint_alloc_parse() - parse all fwnode node properties
+ * @fwnode: pointer to the endpoint's fwnode handle
+ *
+ * All properties are optional. If none are found, we don't set any flags. This
+ * means the port has a static configuration and no properties have to be
+ * specified explicitly. If any properties that identify the bus as parallel
+ * are found and slave-mode isn't set, we set V4L2_MBUS_MASTER. Similarly, if
+ * we recognise the bus as serial CSI-2 and clock-noncontinuous isn't set, we
+ * set the V4L2_MBUS_CSI2_CONTINUOUS_CLOCK flag. The caller should hold a
+ * reference to @fwnode.
+ *
+ * v4l2_fwnode_endpoint_alloc_parse() has two important differences to
+ * v4l2_fwnode_endpoint_parse():
+ *
+ * 1. It also parses variable size data.
+ *
+ * 2. The memory it has allocated to store the variable size data must be freed
+ *    using v4l2_fwnode_endpoint_free() when no longer needed.
+ *
+ * Return: Pointer to v4l2_fwnode_endpoint if successful, on an error pointer
+ * on error.
+ */
 struct v4l2_fwnode_endpoint *v4l2_fwnode_endpoint_alloc_parse(
 	struct fwnode_handle *fwnode);
-void v4l2_fwnode_endpoint_free(struct v4l2_fwnode_endpoint *vep);
+
+/**
+ * v4l2_fwnode_parse_link() - parse a link between two endpoints
+ * @fwnode: pointer to the endpoint's fwnode at the local end of the link
+ * @link: pointer to the V4L2 fwnode link data structure
+ *
+ * Fill the link structure with the local and remote nodes and port numbers.
+ * The local_node and remote_node fields are set to point to the local and
+ * remote port's parent nodes respectively (the port parent node being the
+ * parent node of the port node if that node isn't a 'ports' node, or the
+ * grand-parent node of the port node otherwise).
+ *
+ * A reference is taken to both the local and remote nodes, the caller must use
+ * v4l2_fwnode_put_link() to drop the references when done with the
+ * link.
+ *
+ * Return: 0 on success, or -ENOLINK if the remote endpoint fwnode can't be
+ * found.
+ */
 int v4l2_fwnode_parse_link(struct fwnode_handle *fwnode,
 			   struct v4l2_fwnode_link *link);
+
+/**
+ * v4l2_fwnode_put_link() - drop references to nodes in a link
+ * @link: pointer to the V4L2 fwnode link data structure
+ *
+ * Drop references to the local and remote nodes in the link. This function
+ * must be called on every link parsed with v4l2_fwnode_parse_link().
+ */
 void v4l2_fwnode_put_link(struct v4l2_fwnode_link *link);
 
 /**
-- 
2.11.0

[PATCH v15 23/32] v4l: fwnode: Add a helper function for parsing generic references

[Sakari Ailus]

Add function v4l2_fwnode_reference_parse() for parsing them as async
sub-devices. This can be done on e.g. flash or lens async sub-devices that
are not part of but are associated with a sensor.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
---
 drivers/media/v4l2-core/v4l2-fwnode.c | 69 +++++++++++++++++++++++++++++++++++
 1 file changed, 69 insertions(+)

diff --git a/drivers/media/v4l2-core/v4l2-fwnode.c b/drivers/media/v4l2-core/v4l2-fwnode.c
index 65bdcd59744a..edd2e8d983a1 100644
--- a/drivers/media/v4l2-core/v4l2-fwnode.c
+++ b/drivers/media/v4l2-core/v4l2-fwnode.c
@@ -509,6 +509,75 @@ int v4l2_async_notifier_parse_fwnode_endpoints_by_port(
 }
 EXPORT_SYMBOL_GPL(v4l2_async_notifier_parse_fwnode_endpoints_by_port);
 
+/*
+ * v4l2_fwnode_reference_parse - parse references for async sub-devices
+ * @dev: the device node the properties of which are parsed for references
+ * @notifier: the async notifier where the async subdevs will be added
+ * @prop: the name of the property
+ *
+ * Return: 0 on success
+ *	   -ENOENT if no entries were found
+ *	   -ENOMEM if memory allocation failed
+ *	   -EINVAL if property parsing failed
+ */
+static int v4l2_fwnode_reference_parse(
+	struct device *dev, struct v4l2_async_notifier *notifier,
+	const char *prop)
+{
+	struct fwnode_reference_args args;
+	unsigned int index;
+	int ret;
+
+	for (index = 0;
+	     !(ret = fwnode_property_get_reference_args(
+		       dev_fwnode(dev), prop, NULL, 0, index, &args));
+	     index++)
+		fwnode_handle_put(args.fwnode);
+
+	if (!index)
+		return -ENOENT;
+
+	/*
+	 * Note that right now both -ENODATA and -ENOENT may signal
+	 * out-of-bounds access. Return the error in cases other than that.
+	 */
+	if (ret != -ENOENT && ret != -ENODATA)
+		return ret;
+
+	ret = v4l2_async_notifier_realloc(notifier,
+					  notifier->num_subdevs + index);
+	if (ret)
+		return ret;
+
+	for (index = 0; !fwnode_property_get_reference_args(
+		     dev_fwnode(dev), prop, NULL, 0, index, &args);
+	     index++) {
+		struct v4l2_async_subdev *asd;
+
+		if (WARN_ON(notifier->num_subdevs >= notifier->max_subdevs)) {
+			ret = -EINVAL;
+			goto error;
+		}
+
+		asd = kzalloc(sizeof(*asd), GFP_KERNEL);
+		if (!asd) {
+			ret = -ENOMEM;
+			goto error;
+		}
+
+		notifier->subdevs[notifier->num_subdevs] = asd;
+		asd->match.fwnode.fwnode = args.fwnode;
+		asd->match_type = V4L2_ASYNC_MATCH_FWNODE;
+		notifier->num_subdevs++;
+	}
+
+	return 0;
+
+error:
+	fwnode_handle_put(args.fwnode);
+	return ret;
+}
+
 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Sakari Ailus <sakari.ailus@linux.intel.com>");
 MODULE_AUTHOR("Sylwester Nawrocki <s.nawrocki@samsung.com>");
-- 
2.11.0

[PATCH v15 24/32] v4l: fwnode: Add a helper function to obtain device / integer references

[Sakari Ailus]

v4l2_fwnode_reference_parse_int_prop() will find an fwnode such that under
the device's own fwnode, it will follow child fwnodes with the given
property-value pair and return the resulting fwnode.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
---
 drivers/media/v4l2-core/v4l2-fwnode.c | 207 ++++++++++++++++++++++++++++++++++
 1 file changed, 207 insertions(+)

diff --git a/drivers/media/v4l2-core/v4l2-fwnode.c b/drivers/media/v4l2-core/v4l2-fwnode.c
index edd2e8d983a1..c8acf5bf9916 100644
--- a/drivers/media/v4l2-core/v4l2-fwnode.c
+++ b/drivers/media/v4l2-core/v4l2-fwnode.c
@@ -578,6 +578,213 @@ static int v4l2_fwnode_reference_parse(
 	return ret;
 }
 
+/*
+ * v4l2_fwnode_reference_get_int_prop - parse a reference with integer
+ *					arguments
+ * @dev: struct device pointer
+ * @notifier: notifier for @dev
+ * @prop: the name of the property
+ * @index: the index of the reference to get
+ * @props: the array of integer property names
+ * @nprops: the number of integer property names in @nprops
+ *
+ * First find an fwnode referred to by the reference at @index in @prop.
+ *
+ * Then under that fwnode, @nprops times, for each property in @props,
+ * iteratively follow child nodes starting from fwnode such that they have the
+ * property in @props array at the index of the child node distance from the
+ * root node and the value of that property matching with the integer argument
+ * of the reference, at the same index.
+ *
+ * The child fwnode reched at the end of the iteration is then returned to the
+ * caller.
+ *
+ * For example, if this function was called with arguments and values
+ * @dev corresponding to device "SEN", @prop == "flash-leds", @index
+ * == 1, @props == { "led" }, @nprops == 1, with the ASL snippet below
+ * it would return the node marked with THISONE. The @dev argument in
+ * the ASL below.
+ *
+ *	Device (LED)
+ *	{
+ *		Name (_DSD, Package () {
+ *			ToUUID("dbb8e3e6-5886-4ba6-8795-1319f52a966b"),
+ *			Package () {
+ *				Package () { "led0", "LED0" },
+ *				Package () { "led1", "LED1" },
+ *			}
+ *		})
+ *		Name (LED0, Package () {
+ *			ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
+ *			Package () {
+ *				Package () { "led", 0 },
+ *			}
+ *		})
+ *		Name (LED1, Package () {
+ *			// THISONE
+ *			ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
+ *			Package () {
+ *				Package () { "led", 1 },
+ *			}
+ *		})
+ *	}
+ *
+ *	Device (SEN)
+ *	{
+ *		Name (_DSD, Package () {
+ *			ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
+ *			Package () {
+ *				Package () {
+ *					"flash-leds",
+ *					Package () { ^LED, 0, ^LED, 1 },
+ *				}
+ *			}
+ *		})
+ *	}
+ *
+ * where
+ *
+ *	LED	LED driver device
+ *	LED0	First LED
+ *	LED1	Second LED
+ *	SEN	Camera sensor device (or another device the LED is
+ *		related to)
+ *
+ * Return: 0 on success
+ *	   -ENOENT if no entries (or the property itself) were found
+ *	   -EINVAL if property parsing otherwise failed
+ *	   -ENOMEM if memory allocation failed
+ */
+static struct fwnode_handle *v4l2_fwnode_reference_get_int_prop(
+	struct fwnode_handle *fwnode, const char *prop, unsigned int index,
+	const char **props, unsigned int nprops)
+{
+	struct fwnode_reference_args fwnode_args;
+	unsigned int *args = fwnode_args.args;
+	struct fwnode_handle *child;
+	int ret;
+
+	/*
+	 * Obtain remote fwnode as well as the integer arguments.
+	 *
+	 * Note that right now both -ENODATA and -ENOENT may signal
+	 * out-of-bounds access. Return -ENOENT in that case.
+	 */
+	ret = fwnode_property_get_reference_args(fwnode, prop, NULL, nprops,
+						 index, &fwnode_args);
+	if (ret)
+		return ERR_PTR(ret == -ENODATA ? -ENOENT : ret);
+
+	/*
+	 * Find a node in the tree under the referred fwnode corresponding to
+	 * the integer arguments.
+	 */
+	fwnode = fwnode_args.fwnode;
+	while (nprops--) {
+		u32 val;
+
+		/* Loop over all child nodes under fwnode. */
+		fwnode_for_each_child_node(fwnode, child) {
+			if (fwnode_property_read_u32(child, *props, &val))
+				continue;
+
+			/* Found property, see if its value matches. */
+			if (val == *args)
+				break;
+		}
+
+		fwnode_handle_put(fwnode);
+
+		/* No property found; return an error here. */
+		if (!child) {
+			fwnode = ERR_PTR(-ENOENT);
+			break;
+		}
+
+		props++;
+		args++;
+		fwnode = child;
+	}
+
+	return fwnode;
+}
+
+/*
+ * v4l2_fwnode_reference_parse_int_props - parse references for async sub-devices
+ * @dev: struct device pointer
+ * @notifier: notifier for @dev
+ * @prop: the name of the property
+ * @props: the array of integer property names
+ * @nprops: the number of integer properties
+ *
+ * Use v4l2_fwnode_reference_get_int_prop to find fwnodes through reference in
+ * property @prop with integer arguments with child nodes matching in properties
+ * @props. Then, set up V4L2 async sub-devices for those fwnodes in the notifier
+ * accordingly.
+ *
+ * While it is technically possible to use this function on DT, it is only
+ * meaningful on ACPI. On Device tree you can refer to any node in the tree but
+ * on ACPI the references are limited to devices.
+ *
+ * Return: 0 on success
+ *	   -ENOENT if no entries (or the property itself) were found
+ *	   -EINVAL if property parsing otherwisefailed
+ *	   -ENOMEM if memory allocation failed
+ */
+static int v4l2_fwnode_reference_parse_int_props(
+	struct device *dev, struct v4l2_async_notifier *notifier,
+	const char *prop, const char **props, unsigned int nprops)
+{
+	struct fwnode_handle *fwnode;
+	unsigned int index;
+	int ret;
+
+	for (index = 0; !IS_ERR((fwnode = v4l2_fwnode_reference_get_int_prop(
+					 dev_fwnode(dev), prop, index, props,
+					 nprops))); index++)
+		fwnode_handle_put(fwnode);
+
+	/*
+	 * Note that right now both -ENODATA and -ENOENT may signal
+	 * out-of-bounds access. Return the error in cases other than that.
+	 */
+	if (PTR_ERR(fwnode) != -ENOENT && PTR_ERR(fwnode) != -ENODATA)
+		return PTR_ERR(fwnode);
+
+	ret = v4l2_async_notifier_realloc(notifier,
+					  notifier->num_subdevs + index);
+	if (ret)
+		return -ENOMEM;
+
+	for (index = 0; !IS_ERR((fwnode = v4l2_fwnode_reference_get_int_prop(
+					 dev_fwnode(dev), prop, index, props,
+					 nprops))); index++) {
+		struct v4l2_async_subdev *asd;
+
+		if (WARN_ON(notifier->num_subdevs >= notifier->max_subdevs)) {
+			ret = -EINVAL;
+			goto error;
+		}
+
+		asd = kzalloc(sizeof(struct v4l2_async_subdev), GFP_KERNEL);
+		if (!asd) {
+			ret = -ENOMEM;
+			goto error;
+		}
+
+		notifier->subdevs[notifier->num_subdevs] = asd;
+		asd->match.fwnode.fwnode = fwnode;
+		asd->match_type = V4L2_ASYNC_MATCH_FWNODE;
+		notifier->num_subdevs++;
+	}
+
+	return PTR_ERR(fwnode) == -ENOENT ? 0 : PTR_ERR(fwnode);
+
+error:
+	fwnode_handle_put(fwnode);
+	return ret;
+}
+
 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Sakari Ailus <sakari.ailus@linux.intel.com>");
 MODULE_AUTHOR("Sylwester Nawrocki <s.nawrocki@samsung.com>");
-- 
2.11.0

[PATCH v15 25/32] v4l: fwnode: Add convenience function for parsing common external refs

[Sakari Ailus]

Add v4l2_fwnode_parse_reference_sensor_common for parsing common
sensor properties that refer to adjacent devices such as flash or lens
driver chips.

As this is an association only, there's little a regular driver needs to
know about these devices as such.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
---
 drivers/media/v4l2-core/v4l2-fwnode.c | 35 +++++++++++++++++++++++++++++++++++
 include/media/v4l2-async.h            |  3 ++-
 include/media/v4l2-fwnode.h           | 21 +++++++++++++++++++++
 3 files changed, 58 insertions(+), 1 deletion(-)

diff --git a/drivers/media/v4l2-core/v4l2-fwnode.c b/drivers/media/v4l2-core/v4l2-fwnode.c
index c8acf5bf9916..18ea7cd34f21 100644
--- a/drivers/media/v4l2-core/v4l2-fwnode.c
+++ b/drivers/media/v4l2-core/v4l2-fwnode.c
@@ -785,6 +785,41 @@ static int v4l2_fwnode_reference_parse_int_props(
 	return ret;
 }
 
+int v4l2_async_notifier_parse_fwnode_sensor_common(
+	struct device *dev, struct v4l2_async_notifier *notifier)
+{
+	static const char *led_props[] = { "led" };
+	static const struct {
+		const char *name;
+		const char **props;
+		unsigned int nprops;
+	} props[] = {
+		{ "flash-leds", led_props, ARRAY_SIZE(led_props) },
+		{ "lens-focus", NULL, 0 },
+	};
+	unsigned int i;
+
+	for (i = 0; i < ARRAY_SIZE(props); i++) {
+		int ret;
+
+		if (props[i].props && is_acpi_node(dev_fwnode(dev)))
+			ret = v4l2_fwnode_reference_parse_int_props(
+				dev, notifier, props[i].name,
+				props[i].props, props[i].nprops);
+		else
+			ret = v4l2_fwnode_reference_parse(
+				dev, notifier, props[i].name);
+		if (ret && ret != -ENOENT) {
+			dev_warn(dev, "parsing property \"%s\" failed (%d)\n",
+				 props[i].name, ret);
+			return ret;
+		}
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(v4l2_async_notifier_parse_fwnode_sensor_common);
+
 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Sakari Ailus <sakari.ailus@linux.intel.com>");
 MODULE_AUTHOR("Sylwester Nawrocki <s.nawrocki@samsung.com>");
diff --git a/include/media/v4l2-async.h b/include/media/v4l2-async.h
index d33a52be2501..1e5e3f186b38 100644
--- a/include/media/v4l2-async.h
+++ b/include/media/v4l2-async.h
@@ -155,7 +155,8 @@ void v4l2_async_notifier_unregister(struct v4l2_async_notifier *notifier);
  * Release memory resources related to a notifier, including the async
  * sub-devices allocated for the purposes of the notifier but not the notifier
  * itself. The user is responsible for calling this function to clean up the
- * notifier after calling @v4l2_async_notifier_parse_fwnode_endpoints.
+ * notifier after calling @v4l2_async_notifier_parse_fwnode_endpoints or
+ * @v4l2_fwnode_reference_parse_sensor_common.
  *
  * There is no harm from calling v4l2_async_notifier_cleanup in other
  * cases as long as its memory has been zeroed after it has been
diff --git a/include/media/v4l2-fwnode.h b/include/media/v4l2-fwnode.h
index 671e76e2d285..43fd1a278bcc 100644
--- a/include/media/v4l2-fwnode.h
+++ b/include/media/v4l2-fwnode.h
@@ -319,4 +319,25 @@ int v4l2_async_notifier_parse_fwnode_endpoints_by_port(
 			      struct v4l2_fwnode_endpoint *vep,
 			      struct v4l2_async_subdev *asd));
 
+/**
+ * v4l2_fwnode_reference_parse_sensor_common - parse common references on
+ *					       sensors for async sub-devices
+ * @dev: the device node the properties of which are parsed for references
+ * @notifier: the async notifier where the async subdevs will be added
+ *
+ * Parse common sensor properties for remote devices related to the
+ * sensor and set up async sub-devices for them.
+ *
+ * Any notifier populated using this function must be released with a call to
+ * v4l2_async_notifier_release() after it has been unregistered and the async
+ * sub-devices are no longer in use, even in the case the function returned an
+ * error.
+ *
+ * Return: 0 on success
+ *	   -ENOMEM if memory allocation failed
+ *	   -EINVAL if property parsing failed
+ */
+int v4l2_async_notifier_parse_fwnode_sensor_common(
+	struct device *dev, struct v4l2_async_notifier *notifier);
+
 #endif /* _V4L2_FWNODE_H */
-- 
2.11.0

[PATCH v15 26/32] v4l: fwnode: Add a convenience function for registering sensors

[Sakari Ailus]

Add a convenience function for parsing firmware for information on related
devices using v4l2_async_notifier_parse_fwnode_sensor_common() registering
the notifier and finally the async sub-device itself.

This should be useful for sensor drivers that do not have device specific
requirements related to firmware information parsing or the async
framework.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
---
 drivers/media/v4l2-core/v4l2-async.c  | 19 ++++++++++++----
 drivers/media/v4l2-core/v4l2-fwnode.c | 41 +++++++++++++++++++++++++++++++++++
 include/media/v4l2-async.h            | 22 +++++++++++++++++++
 include/media/v4l2-subdev.h           |  3 +++
 4 files changed, 81 insertions(+), 4 deletions(-)

diff --git a/drivers/media/v4l2-core/v4l2-async.c b/drivers/media/v4l2-core/v4l2-async.c
index e1fe3567127a..ae026eee3d03 100644
--- a/drivers/media/v4l2-core/v4l2-async.c
+++ b/drivers/media/v4l2-core/v4l2-async.c
@@ -496,19 +496,25 @@ int v4l2_async_subdev_notifier_register(struct v4l2_subdev *sd,
 }
 EXPORT_SYMBOL(v4l2_async_subdev_notifier_register);
 
-void v4l2_async_notifier_unregister(struct v4l2_async_notifier *notifier)
+static void __v4l2_async_notifier_unregister(
+	struct v4l2_async_notifier *notifier)
 {
-	if (!notifier->v4l2_dev && !notifier->sd)
+	if (!notifier || (!notifier->v4l2_dev && !notifier->sd))
 		return;
 
-	mutex_lock(&list_lock);
-
 	v4l2_async_notifier_unbind_all_subdevs(notifier);
 
 	notifier->sd = NULL;
 	notifier->v4l2_dev = NULL;
 
 	list_del(&notifier->list);
+}
+
+void v4l2_async_notifier_unregister(struct v4l2_async_notifier *notifier)
+{
+	mutex_lock(&list_lock);
+
+	__v4l2_async_notifier_unregister(notifier);
 
 	mutex_unlock(&list_lock);
 }
@@ -618,6 +624,11 @@ void v4l2_async_unregister_subdev(struct v4l2_subdev *sd)
 {
 	mutex_lock(&list_lock);
 
+	__v4l2_async_notifier_unregister(sd->subdev_notifier);
+	v4l2_async_notifier_cleanup(sd->subdev_notifier);
+	kfree(sd->subdev_notifier);
+	sd->subdev_notifier = NULL;
+
 	if (sd->asd) {
 		struct v4l2_async_notifier *notifier = sd->notifier;
 
diff --git a/drivers/media/v4l2-core/v4l2-fwnode.c b/drivers/media/v4l2-core/v4l2-fwnode.c
index 18ea7cd34f21..e5856f1e39b9 100644
--- a/drivers/media/v4l2-core/v4l2-fwnode.c
+++ b/drivers/media/v4l2-core/v4l2-fwnode.c
@@ -29,6 +29,7 @@
 
 #include <media/v4l2-async.h>
 #include <media/v4l2-fwnode.h>
+#include <media/v4l2-subdev.h>
 
 enum v4l2_fwnode_bus_type {
 	V4L2_FWNODE_BUS_TYPE_GUESS = 0,
@@ -820,6 +821,46 @@ int v4l2_async_notifier_parse_fwnode_sensor_common(
 }
 EXPORT_SYMBOL_GPL(v4l2_async_notifier_parse_fwnode_sensor_common);
 
+int v4l2_async_register_subdev_sensor_common(struct v4l2_subdev *sd)
+{
+	struct v4l2_async_notifier *notifier;
+	int ret;
+
+	if (WARN_ON(!sd->dev))
+		return -ENODEV;
+
+	notifier = kzalloc(sizeof(*notifier), GFP_KERNEL);
+	if (!notifier)
+		return -ENOMEM;
+
+	ret = v4l2_async_notifier_parse_fwnode_sensor_common(sd->dev,
+							     notifier);
+	if (ret < 0)
+		goto out_cleanup;
+
+	ret = v4l2_async_subdev_notifier_register(sd, notifier);
+	if (ret < 0)
+		goto out_cleanup;
+
+	ret = v4l2_async_register_subdev(sd);
+	if (ret < 0)
+		goto out_unregister;
+
+	sd->subdev_notifier = notifier;
+
+	return 0;
+
+out_unregister:
+	v4l2_async_notifier_unregister(notifier);
+
+out_cleanup:
+	v4l2_async_notifier_cleanup(notifier);
+	kfree(notifier);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(v4l2_async_register_subdev_sensor_common);
+
 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Sakari Ailus <sakari.ailus@linux.intel.com>");
 MODULE_AUTHOR("Sylwester Nawrocki <s.nawrocki@samsung.com>");
diff --git a/include/media/v4l2-async.h b/include/media/v4l2-async.h
index 1e5e3f186b38..65f87e80081a 100644
--- a/include/media/v4l2-async.h
+++ b/include/media/v4l2-async.h
@@ -173,6 +173,28 @@ void v4l2_async_notifier_cleanup(struct v4l2_async_notifier *notifier);
 int v4l2_async_register_subdev(struct v4l2_subdev *sd);
 
 /**
+ * v4l2_async_register_subdev_sensor_common - registers a sensor sub-device to
+ *					      the asynchronous sub-device
+ *					      framework and parse set up common
+ *					      sensor related devices
+ *
+ * @sd: pointer to struct &v4l2_subdev
+ *
+ * This function is just like v4l2_async_register_subdev() with the exception
+ * that calling it will also parse firmware interfaces for remote references
+ * using v4l2_async_notifier_parse_fwnode_sensor_common() and registers the
+ * async sub-devices. The sub-device is similarly unregistered by calling
+ * v4l2_async_unregister_subdev().
+ *
+ * While registered, the subdev module is marked as in-use.
+ *
+ * An error is returned if the module is no longer loaded on any attempts
+ * to register it.
+ */
+int __must_check v4l2_async_register_subdev_sensor_common(
+	struct v4l2_subdev *sd);
+
+/**
  * v4l2_async_unregister_subdev - unregisters a sub-device to the asynchronous
  * 	subdevice framework
  *
diff --git a/include/media/v4l2-subdev.h b/include/media/v4l2-subdev.h
index e83872078376..ec399c770301 100644
--- a/include/media/v4l2-subdev.h
+++ b/include/media/v4l2-subdev.h
@@ -793,6 +793,8 @@ struct v4l2_subdev_platform_data {
  *	list.
  * @asd: Pointer to respective &struct v4l2_async_subdev.
  * @notifier: Pointer to the managing notifier.
+ * @subdev_notifier: A sub-device notifier implicitly registered for the sub-
+ *		     device using v4l2_device_register_sensor_subdev().
  * @pdata: common part of subdevice platform data
  *
  * Each instance of a subdev driver should create this struct, either
@@ -823,6 +825,7 @@ struct v4l2_subdev {
 	struct list_head async_list;
 	struct v4l2_async_subdev *asd;
 	struct v4l2_async_notifier *notifier;
+	struct v4l2_async_notifier *subdev_notifier;
 	struct v4l2_subdev_platform_data *pdata;
 };
 
-- 
2.11.0

[PATCH v15 27/32] dt: bindings: smiapp: Document lens-focus and flash-leds properties

[Sakari Ailus]

Document optional lens-focus and flash-leds properties for the smiapp
driver.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
---
 Documentation/devicetree/bindings/media/i2c/nokia,smia.txt | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/Documentation/devicetree/bindings/media/i2c/nokia,smia.txt b/Documentation/devicetree/bindings/media/i2c/nokia,smia.txt
index 855e1faf73e2..33f10a94c381 100644
--- a/Documentation/devicetree/bindings/media/i2c/nokia,smia.txt
+++ b/Documentation/devicetree/bindings/media/i2c/nokia,smia.txt
@@ -27,6 +27,8 @@ Optional properties
 - nokia,nvm-size: The size of the NVM, in bytes. If the size is not given,
   the NVM contents will not be read.
 - reset-gpios: XSHUTDOWN GPIO
+- flash-leds: See ../video-interfaces.txt
+- lens-focus: See ../video-interfaces.txt
 
 
 Endpoint node mandatory properties
-- 
2.11.0

[PATCH v15 28/32] smiapp: Add support for flash and lens devices

[Sakari Ailus]

Parse async sub-devices related to the sensor by switching the async
sub-device registration function.

These types devices aren't directly related to the sensor, but are
nevertheless handled by the smiapp driver due to the relationship of these
component to the main part of the camera module --- the sensor.

This does not yet address providing the user space with information on how
to associate the sensor or lens devices but the kernel now has the
necessary information to do that.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
---
 drivers/media/i2c/smiapp/smiapp-core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/media/i2c/smiapp/smiapp-core.c b/drivers/media/i2c/smiapp/smiapp-core.c
index 700f433261d0..3d9a251ca825 100644
--- a/drivers/media/i2c/smiapp/smiapp-core.c
+++ b/drivers/media/i2c/smiapp/smiapp-core.c
@@ -3092,7 +3092,7 @@ static int smiapp_probe(struct i2c_client *client,
 	if (rval < 0)
 		goto out_media_entity_cleanup;
 
-	rval = v4l2_async_register_subdev(&sensor->src->sd);
+	rval = v4l2_async_register_subdev_sensor_common(&sensor->src->sd);
 	if (rval < 0)
 		goto out_media_entity_cleanup;
 
-- 
2.11.0

[PATCH v15 29/32] et8ek8: Add support for flash and lens devices

[Sakari Ailus]

Parse async sub-devices related to the sensor by switching the async
sub-device registration function.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
---
 drivers/media/i2c/et8ek8/et8ek8_driver.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/media/i2c/et8ek8/et8ek8_driver.c b/drivers/media/i2c/et8ek8/et8ek8_driver.c
index c14f0fd6ded3..e9eff9039ef5 100644
--- a/drivers/media/i2c/et8ek8/et8ek8_driver.c
+++ b/drivers/media/i2c/et8ek8/et8ek8_driver.c
@@ -1453,7 +1453,7 @@ static int et8ek8_probe(struct i2c_client *client,
 		goto err_mutex;
 	}
 
-	ret = v4l2_async_register_subdev(&sensor->subdev);
+	ret = v4l2_async_register_subdev_sensor_common(&sensor->subdev);
 	if (ret < 0)
 		goto err_entity;
 
-- 
2.11.0

[PATCH v15 30/32] ov5670: Add support for flash and lens devices

[Sakari Ailus]

Parse async sub-devices related to the sensor by switching the async
sub-device registration function.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
---
 drivers/media/i2c/ov5670.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/media/i2c/ov5670.c b/drivers/media/i2c/ov5670.c
index 6f7a1d6d2200..0a1723f5a66c 100644
--- a/drivers/media/i2c/ov5670.c
+++ b/drivers/media/i2c/ov5670.c
@@ -2514,7 +2514,7 @@ static int ov5670_probe(struct i2c_client *client)
 	}
 
 	/* Async register for subdev */
-	ret = v4l2_async_register_subdev(&ov5670->sd);
+	ret = v4l2_async_register_subdev_sensor_common(&ov5670->sd);
 	if (ret < 0) {
 		err_msg = "v4l2_async_register_subdev() error";
 		goto error_entity_cleanup;
-- 
2.11.0

[PATCH v15 31/32] ov13858: Add support for flash and lens devices

[Sakari Ailus]

Parse async sub-devices related to the sensor by switching the async
sub-device registration function.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
---
 drivers/media/i2c/ov13858.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/media/i2c/ov13858.c b/drivers/media/i2c/ov13858.c
index af7af0d14c69..c86525982e17 100644
--- a/drivers/media/i2c/ov13858.c
+++ b/drivers/media/i2c/ov13858.c
@@ -1746,7 +1746,7 @@ static int ov13858_probe(struct i2c_client *client,
 		goto error_handler_free;
 	}
 
-	ret = v4l2_async_register_subdev(&ov13858->sd);
+	ret = v4l2_async_register_subdev_sensor_common(&ov13858->sd);
 	if (ret < 0)
 		goto error_media_entity;
 
-- 
2.11.0

[PATCH v15 32/32] arm: dts: omap3: N9/N950: Add flash references to the camera

[Sakari Ailus]

Add flash and indicator LED phandles to the sensor node.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
---
 arch/arm/boot/dts/omap3-n9.dts       | 1 +
 arch/arm/boot/dts/omap3-n950-n9.dtsi | 4 ++--
 arch/arm/boot/dts/omap3-n950.dts     | 1 +
 3 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/arch/arm/boot/dts/omap3-n9.dts b/arch/arm/boot/dts/omap3-n9.dts
index b9e58c536afd..39e35f8b8206 100644
--- a/arch/arm/boot/dts/omap3-n9.dts
+++ b/arch/arm/boot/dts/omap3-n9.dts
@@ -26,6 +26,7 @@
 		clocks = <&isp 0>;
 		clock-frequency = <9600000>;
 		nokia,nvm-size = <(16 * 64)>;
+		flash-leds = <&as3645a_flash &as3645a_indicator>;
 		port {
 			smia_1_1: endpoint {
 				link-frequencies = /bits/ 64 <199200000 210000000 499200000>;
diff --git a/arch/arm/boot/dts/omap3-n950-n9.dtsi b/arch/arm/boot/dts/omap3-n950-n9.dtsi
index 1b0bd72945f2..12fbb3da5fce 100644
--- a/arch/arm/boot/dts/omap3-n950-n9.dtsi
+++ b/arch/arm/boot/dts/omap3-n950-n9.dtsi
@@ -271,14 +271,14 @@
 		#size-cells = <0>;
 		reg = <0x30>;
 		compatible = "ams,as3645a";
-		flash@0 {
+		as3645a_flash: flash@0 {
 			reg = <0x0>;
 			flash-timeout-us = <150000>;
 			flash-max-microamp = <320000>;
 			led-max-microamp = <60000>;
 			ams,input-max-microamp = <1750000>;
 		};
-		indicator@1 {
+		as3645a_indicator: indicator@1 {
 			reg = <0x1>;
 			led-max-microamp = <10000>;
 		};
diff --git a/arch/arm/boot/dts/omap3-n950.dts b/arch/arm/boot/dts/omap3-n950.dts
index 646601a3ebd8..c354a1ed1e70 100644
--- a/arch/arm/boot/dts/omap3-n950.dts
+++ b/arch/arm/boot/dts/omap3-n950.dts
@@ -60,6 +60,7 @@
 		clocks = <&isp 0>;
 		clock-frequency = <9600000>;
 		nokia,nvm-size = <(16 * 64)>;
+		flash-leds = <&as3645a_flash &as3645a_indicator>;
 		port {
 			smia_1_1: endpoint {
 				link-frequencies = /bits/ 64 <210000000 333600000 398400000>;
-- 
2.11.0

Re: [PATCH v15 00/32] Unified fwnode endpoint parser, async sub-device notifier support, N9 flash DTS

[Sakari Ailus]

On Thu, Oct 05, 2017 at 12:50:19AM +0300, Sakari Ailus wrote:
> Hi folks,
> 
> 	I've dropped the full set from devicetree and linux-acpi lists;
> 	let me know if you want it back. The entire set is posted to
> 	linux-media list.

Here's the diff between v14 and v15. The patches can be found here, with
the dependencies:

<URL:https://git.linuxtv.org/sailus/media_tree.git/log/?h=fwnode-parse>

diff --git a/drivers/media/v4l2-core/v4l2-async.c b/drivers/media/v4l2-core/v4l2-async.c
index 5aae5cb38b81..ae026eee3d03 100644
--- a/drivers/media/v4l2-core/v4l2-async.c
+++ b/drivers/media/v4l2-core/v4l2-async.c
@@ -248,18 +248,20 @@ static int v4l2_async_match_notify(struct v4l2_async_notifier *notifier,
 	list_move(&sd->async_list, &notifier->done);
 
 	/*
-	 * See if the sub-device has a notifier. If it does, proceed
-	 * with checking for its async sub-devices.
+	 * See if the sub-device has a notifier. If not, return here.
 	 */
 	subdev_notifier = v4l2_async_find_subdev_notifier(sd);
-	if (subdev_notifier && !subdev_notifier->parent) {
-		subdev_notifier->parent = notifier;
-		ret = v4l2_async_notifier_try_all_subdevs(subdev_notifier);
-		if (ret)
-			return ret;
-	}
+	if (!subdev_notifier || subdev_notifier->parent)
+		return 0;
 
-	return 0;
+	/*
+	 * Proceed with checking for the sub-device notifier's async
+	 * sub-devices, and return the result. The error will be handled by the
+	 * caller.
+	 */
+	subdev_notifier->parent = notifier;
+
+	return v4l2_async_notifier_try_all_subdevs(subdev_notifier);
 }
 
 /* Test all async sub-devices in a notifier for a match. */
@@ -304,7 +306,28 @@ static void v4l2_async_cleanup(struct v4l2_subdev *sd)
 	/* Subdevice driver will reprobe and put the subdev back onto the list */
 	list_del_init(&sd->async_list);
 	sd->asd = NULL;
-	sd->dev = NULL;
+}
+
+/* Unbind all sub-devices in the notifier tree. */
+static void v4l2_async_notifier_unbind_all_subdevs(
+	struct v4l2_async_notifier *notifier)
+{
+	struct v4l2_subdev *sd, *tmp;
+
+	list_for_each_entry_safe(sd, tmp, &notifier->done, async_list) {
+		struct v4l2_async_notifier *subdev_notifier =
+			v4l2_async_find_subdev_notifier(sd);
+
+		if (subdev_notifier)
+			v4l2_async_notifier_unbind_all_subdevs(subdev_notifier);
+
+		v4l2_async_notifier_call_unbind(notifier, sd, sd->asd);
+		v4l2_async_cleanup(sd);
+
+		list_move(&sd->async_list, &subdev_list);
+	}
+
+	notifier->parent = NULL;
 }
 
 /* See if an fwnode can be found in a notifier's lists. */
@@ -412,9 +435,11 @@ static int __v4l2_async_notifier_register(struct v4l2_async_notifier *notifier)
 
 	ret = v4l2_async_notifier_try_all_subdevs(notifier);
 	if (ret)
-		goto out_unlock;
+		goto err_unbind;
 
 	ret = v4l2_async_notifier_try_complete(notifier);
+	if (ret)
+		goto err_unbind;
 
 	/* Keep also completed notifiers on the list */
 	list_add(&notifier->list, &notifier_list);
@@ -422,69 +447,74 @@ static int __v4l2_async_notifier_register(struct v4l2_async_notifier *notifier)
 out_unlock:
 	mutex_unlock(&list_lock);
 
+	return 0;
+
+err_unbind:
+	/*
+	 * On failure, unbind all sub-devices registered through this notifier.
+	 */
+	v4l2_async_notifier_unbind_all_subdevs(notifier);
+
+	mutex_unlock(&list_lock);
+
 	return ret;
 }
 
 int v4l2_async_notifier_register(struct v4l2_device *v4l2_dev,
 				 struct v4l2_async_notifier *notifier)
 {
+	int ret;
+
 	if (WARN_ON(!v4l2_dev || notifier->sd))
 		return -EINVAL;
 
 	notifier->v4l2_dev = v4l2_dev;
 
-	return __v4l2_async_notifier_register(notifier);
+	ret = __v4l2_async_notifier_register(notifier);
+	if (ret)
+		notifier->v4l2_dev = NULL;
+
+	return ret;
 }
 EXPORT_SYMBOL(v4l2_async_notifier_register);
 
 int v4l2_async_subdev_notifier_register(struct v4l2_subdev *sd,
 					struct v4l2_async_notifier *notifier)
 {
+	int ret;
+
 	if (WARN_ON(!sd || notifier->v4l2_dev))
 		return -EINVAL;
 
 	notifier->sd = sd;
 
-	return __v4l2_async_notifier_register(notifier);
+	ret = __v4l2_async_notifier_register(notifier);
+	if (ret)
+		notifier->sd = NULL;
+
+	return ret;
 }
 EXPORT_SYMBOL(v4l2_async_subdev_notifier_register);
 
-/* Unbind all sub-devices in the notifier tree. */
-static void v4l2_async_notifier_unbind_all_subdevs(
+static void __v4l2_async_notifier_unregister(
 	struct v4l2_async_notifier *notifier)
 {
-	struct v4l2_subdev *sd, *tmp;
-
-	list_for_each_entry_safe(sd, tmp, &notifier->done, async_list) {
-		struct v4l2_async_notifier *subdev_notifier =
-			v4l2_async_find_subdev_notifier(sd);
-
-		if (subdev_notifier)
-			v4l2_async_notifier_unbind_all_subdevs(subdev_notifier);
-
-		v4l2_async_cleanup(sd);
+	if (!notifier || (!notifier->v4l2_dev && !notifier->sd))
+		return;
 
-		v4l2_async_notifier_call_unbind(notifier, sd, sd->asd);
+	v4l2_async_notifier_unbind_all_subdevs(notifier);
 
-		list_move(&sd->async_list, &subdev_list);
-	}
+	notifier->sd = NULL;
+	notifier->v4l2_dev = NULL;
 
-	notifier->parent = NULL;
+	list_del(&notifier->list);
 }
 
 void v4l2_async_notifier_unregister(struct v4l2_async_notifier *notifier)
 {
-	if (!notifier->v4l2_dev && !notifier->sd)
-		return;
-
 	mutex_lock(&list_lock);
 
-	v4l2_async_notifier_unbind_all_subdevs(notifier);
-
-	notifier->sd = NULL;
-	notifier->v4l2_dev = NULL;
-
-	list_del(&notifier->list);
+	__v4l2_async_notifier_unregister(notifier);
 
 	mutex_unlock(&list_lock);
 }
@@ -522,7 +552,9 @@ EXPORT_SYMBOL_GPL(v4l2_async_notifier_cleanup);
 
 int v4l2_async_register_subdev(struct v4l2_subdev *sd)
 {
+	struct v4l2_async_notifier *subdev_notifier;
 	struct v4l2_async_notifier *notifier;
+	int ret;
 
 	/*
 	 * No reference taken. The reference is held by the device
@@ -549,47 +581,64 @@ int v4l2_async_register_subdev(struct v4l2_subdev *sd)
 		if (!asd)
 			continue;
 
-		ret = v4l2_async_match_notify(notifier, v4l2_dev, sd, asd);
+		ret = v4l2_async_match_notify(notifier, notifier->v4l2_dev, sd,
+					      asd);
+		if (ret)
+			goto err_unbind;
 
-		if (!ret)
-			ret = v4l2_async_notifier_try_complete(notifier);
+		ret = v4l2_async_notifier_try_complete(notifier);
+		if (ret)
+			goto err_unbind;
 
-		mutex_unlock(&list_lock);
-		return ret;
+		goto out_unlock;
 	}
 
 	/* None matched, wait for hot-plugging */
 	list_add(&sd->async_list, &subdev_list);
 
+out_unlock:
 	mutex_unlock(&list_lock);
 
 	return 0;
+
+err_unbind:
+	/*
+	 * Complete failed. Unbind the sub-devices bound through registering
+	 * this async sub-device.
+	 */
+	subdev_notifier = v4l2_async_find_subdev_notifier(sd);
+	if (subdev_notifier)
+		v4l2_async_notifier_unbind_all_subdevs(subdev_notifier);
+
+	if (sd->asd)
+		v4l2_async_notifier_call_unbind(notifier, sd, sd->asd);
+	v4l2_async_cleanup(sd);
+
+	mutex_unlock(&list_lock);
+
+	return ret;
 }
 EXPORT_SYMBOL(v4l2_async_register_subdev);
 
 void v4l2_async_unregister_subdev(struct v4l2_subdev *sd)
 {
-	struct v4l2_async_notifier *notifier = sd->notifier;
+	mutex_lock(&list_lock);
 
-	if (sd->subdev_notifier)
-		v4l2_async_notifier_unregister(sd->subdev_notifier);
+	__v4l2_async_notifier_unregister(sd->subdev_notifier);
 	v4l2_async_notifier_cleanup(sd->subdev_notifier);
 	kfree(sd->subdev_notifier);
+	sd->subdev_notifier = NULL;
 
-	if (!sd->asd) {
-		if (!list_empty(&sd->async_list))
-			v4l2_async_cleanup(sd);
-		return;
-	}
+	if (sd->asd) {
+		struct v4l2_async_notifier *notifier = sd->notifier;
 
-	mutex_lock(&list_lock);
+		list_add(&sd->asd->list, &notifier->waiting);
 
-	list_add(&sd->asd->list, &notifier->waiting);
+		v4l2_async_notifier_call_unbind(notifier, sd, sd->asd);
+	}
 
 	v4l2_async_cleanup(sd);
 
-	v4l2_async_notifier_call_unbind(notifier, sd, sd->asd);
-
 	mutex_unlock(&list_lock);
 }
 EXPORT_SYMBOL(v4l2_async_unregister_subdev);
diff --git a/include/media/v4l2-async.h b/include/media/v4l2-async.h
index 74f2ea27d117..65f87e80081a 100644
--- a/include/media/v4l2-async.h
+++ b/include/media/v4l2-async.h
@@ -201,5 +201,4 @@ int __must_check v4l2_async_register_subdev_sensor_common(
  * @sd: pointer to &struct v4l2_subdev
  */
 void v4l2_async_unregister_subdev(struct v4l2_subdev *sd);
-
 #endif
diff --git a/include/media/v4l2-fwnode.h b/include/media/v4l2-fwnode.h
index 834e74246412..43fd1a278bcc 100644
--- a/include/media/v4l2-fwnode.h
+++ b/include/media/v4l2-fwnode.h
@@ -137,7 +137,7 @@ struct v4l2_fwnode_link {
 int v4l2_fwnode_endpoint_parse(struct fwnode_handle *fwnode,
 			       struct v4l2_fwnode_endpoint *vep);
 
-/*
+/**
  * v4l2_fwnode_endpoint_free() - free the V4L2 fwnode acquired by
  * v4l2_fwnode_endpoint_alloc_parse()
  * @vep - the V4L2 fwnode the resources of which are to be released


-- 
Sakari Ailus
e-mail: sakari.ailus@iki.fi

[PATCH v15.1 22/32] v4l: fwnode: Move KernelDoc documentation to the header

[Sakari Ailus]

In V4L2 the practice is to have the KernelDoc documentation in the header
and not in .c source code files. This consequently makes the V4L2 fwnode
function documentation part of the Media documentation build.

Also correct the link related function and argument naming in
documentation and add an asterisk to v4l2_fwnode_endpoint_free()
documentation to make it proper KernelDoc documentation.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
---
since v15:

- Fix vep parameter documentation for v4l2_fwnode_endpoint_free

 drivers/media/v4l2-core/v4l2-fwnode.c | 75 --------------------------------
 include/media/v4l2-fwnode.h           | 81 ++++++++++++++++++++++++++++++++++-
 2 files changed, 80 insertions(+), 76 deletions(-)

diff --git a/drivers/media/v4l2-core/v4l2-fwnode.c b/drivers/media/v4l2-core/v4l2-fwnode.c
index df0695b7bbcc..65bdcd59744a 100644
--- a/drivers/media/v4l2-core/v4l2-fwnode.c
+++ b/drivers/media/v4l2-core/v4l2-fwnode.c
@@ -183,25 +183,6 @@ v4l2_fwnode_endpoint_parse_csi1_bus(struct fwnode_handle *fwnode,
 		vep->bus_type = V4L2_MBUS_CSI1;
 }
 
-/**
- * v4l2_fwnode_endpoint_parse() - parse all fwnode node properties
- * @fwnode: pointer to the endpoint's fwnode handle
- * @vep: pointer to the V4L2 fwnode data structure
- *
- * All properties are optional. If none are found, we don't set any flags. This
- * means the port has a static configuration and no properties have to be
- * specified explicitly. If any properties that identify the bus as parallel
- * are found and slave-mode isn't set, we set V4L2_MBUS_MASTER. Similarly, if
- * we recognise the bus as serial CSI-2 and clock-noncontinuous isn't set, we
- * set the V4L2_MBUS_CSI2_CONTINUOUS_CLOCK flag. The caller should hold a
- * reference to @fwnode.
- *
- * NOTE: This function does not parse properties the size of which is variable
- * without a low fixed limit. Please use v4l2_fwnode_endpoint_alloc_parse() in
- * new drivers instead.
- *
- * Return: 0 on success or a negative error code on failure.
- */
 int v4l2_fwnode_endpoint_parse(struct fwnode_handle *fwnode,
 			       struct v4l2_fwnode_endpoint *vep)
 {
@@ -241,14 +222,6 @@ int v4l2_fwnode_endpoint_parse(struct fwnode_handle *fwnode,
 }
 EXPORT_SYMBOL_GPL(v4l2_fwnode_endpoint_parse);
 
-/*
- * v4l2_fwnode_endpoint_free() - free the V4L2 fwnode acquired by
- * v4l2_fwnode_endpoint_alloc_parse()
- * @vep - the V4L2 fwnode the resources of which are to be released
- *
- * It is safe to call this function with NULL argument or on a V4L2 fwnode the
- * parsing of which failed.
- */
 void v4l2_fwnode_endpoint_free(struct v4l2_fwnode_endpoint *vep)
 {
 	if (IS_ERR_OR_NULL(vep))
@@ -259,29 +232,6 @@ void v4l2_fwnode_endpoint_free(struct v4l2_fwnode_endpoint *vep)
 }
 EXPORT_SYMBOL_GPL(v4l2_fwnode_endpoint_free);
 
-/**
- * v4l2_fwnode_endpoint_alloc_parse() - parse all fwnode node properties
- * @fwnode: pointer to the endpoint's fwnode handle
- *
- * All properties are optional. If none are found, we don't set any flags. This
- * means the port has a static configuration and no properties have to be
- * specified explicitly. If any properties that identify the bus as parallel
- * are found and slave-mode isn't set, we set V4L2_MBUS_MASTER. Similarly, if
- * we recognise the bus as serial CSI-2 and clock-noncontinuous isn't set, we
- * set the V4L2_MBUS_CSI2_CONTINUOUS_CLOCK flag. The caller should hold a
- * reference to @fwnode.
- *
- * v4l2_fwnode_endpoint_alloc_parse() has two important differences to
- * v4l2_fwnode_endpoint_parse():
- *
- * 1. It also parses variable size data.
- *
- * 2. The memory it has allocated to store the variable size data must be freed
- *    using v4l2_fwnode_endpoint_free() when no longer needed.
- *
- * Return: Pointer to v4l2_fwnode_endpoint if successful, on an error pointer
- * on error.
- */
 struct v4l2_fwnode_endpoint *v4l2_fwnode_endpoint_alloc_parse(
 	struct fwnode_handle *fwnode)
 {
@@ -324,24 +274,6 @@ struct v4l2_fwnode_endpoint *v4l2_fwnode_endpoint_alloc_parse(
 }
 EXPORT_SYMBOL_GPL(v4l2_fwnode_endpoint_alloc_parse);
 
-/**
- * v4l2_fwnode_endpoint_parse_link() - parse a link between two endpoints
- * @__fwnode: pointer to the endpoint's fwnode at the local end of the link
- * @link: pointer to the V4L2 fwnode link data structure
- *
- * Fill the link structure with the local and remote nodes and port numbers.
- * The local_node and remote_node fields are set to point to the local and
- * remote port's parent nodes respectively (the port parent node being the
- * parent node of the port node if that node isn't a 'ports' node, or the
- * grand-parent node of the port node otherwise).
- *
- * A reference is taken to both the local and remote nodes, the caller must use
- * v4l2_fwnode_endpoint_put_link() to drop the references when done with the
- * link.
- *
- * Return: 0 on success, or -ENOLINK if the remote endpoint fwnode can't be
- * found.
- */
 int v4l2_fwnode_parse_link(struct fwnode_handle *__fwnode,
 			   struct v4l2_fwnode_link *link)
 {
@@ -376,13 +308,6 @@ int v4l2_fwnode_parse_link(struct fwnode_handle *__fwnode,
 }
 EXPORT_SYMBOL_GPL(v4l2_fwnode_parse_link);
 
-/**
- * v4l2_fwnode_put_link() - drop references to nodes in a link
- * @link: pointer to the V4L2 fwnode link data structure
- *
- * Drop references to the local and remote nodes in the link. This function
- * must be called on every link parsed with v4l2_fwnode_parse_link().
- */
 void v4l2_fwnode_put_link(struct v4l2_fwnode_link *link)
 {
 	fwnode_handle_put(link->local_node);
diff --git a/include/media/v4l2-fwnode.h b/include/media/v4l2-fwnode.h
index ac605af9b877..105cfeee44ef 100644
--- a/include/media/v4l2-fwnode.h
+++ b/include/media/v4l2-fwnode.h
@@ -115,13 +115,92 @@ struct v4l2_fwnode_link {
 	unsigned int remote_port;
 };
 
+/**
+ * v4l2_fwnode_endpoint_parse() - parse all fwnode node properties
+ * @fwnode: pointer to the endpoint's fwnode handle
+ * @vep: pointer to the V4L2 fwnode data structure
+ *
+ * All properties are optional. If none are found, we don't set any flags. This
+ * means the port has a static configuration and no properties have to be
+ * specified explicitly. If any properties that identify the bus as parallel
+ * are found and slave-mode isn't set, we set V4L2_MBUS_MASTER. Similarly, if
+ * we recognise the bus as serial CSI-2 and clock-noncontinuous isn't set, we
+ * set the V4L2_MBUS_CSI2_CONTINUOUS_CLOCK flag. The caller should hold a
+ * reference to @fwnode.
+ *
+ * NOTE: This function does not parse properties the size of which is variable
+ * without a low fixed limit. Please use v4l2_fwnode_endpoint_alloc_parse() in
+ * new drivers instead.
+ *
+ * Return: 0 on success or a negative error code on failure.
+ */
 int v4l2_fwnode_endpoint_parse(struct fwnode_handle *fwnode,
 			       struct v4l2_fwnode_endpoint *vep);
+
+/**
+ * v4l2_fwnode_endpoint_free() - free the V4L2 fwnode acquired by
+ * v4l2_fwnode_endpoint_alloc_parse()
+ * @vep: the V4L2 fwnode the resources of which are to be released
+ *
+ * It is safe to call this function with NULL argument or on a V4L2 fwnode the
+ * parsing of which failed.
+ */
+void v4l2_fwnode_endpoint_free(struct v4l2_fwnode_endpoint *vep);
+
+/**
+ * v4l2_fwnode_endpoint_alloc_parse() - parse all fwnode node properties
+ * @fwnode: pointer to the endpoint's fwnode handle
+ *
+ * All properties are optional. If none are found, we don't set any flags. This
+ * means the port has a static configuration and no properties have to be
+ * specified explicitly. If any properties that identify the bus as parallel
+ * are found and slave-mode isn't set, we set V4L2_MBUS_MASTER. Similarly, if
+ * we recognise the bus as serial CSI-2 and clock-noncontinuous isn't set, we
+ * set the V4L2_MBUS_CSI2_CONTINUOUS_CLOCK flag. The caller should hold a
+ * reference to @fwnode.
+ *
+ * v4l2_fwnode_endpoint_alloc_parse() has two important differences to
+ * v4l2_fwnode_endpoint_parse():
+ *
+ * 1. It also parses variable size data.
+ *
+ * 2. The memory it has allocated to store the variable size data must be freed
+ *    using v4l2_fwnode_endpoint_free() when no longer needed.
+ *
+ * Return: Pointer to v4l2_fwnode_endpoint if successful, on an error pointer
+ * on error.
+ */
 struct v4l2_fwnode_endpoint *v4l2_fwnode_endpoint_alloc_parse(
 	struct fwnode_handle *fwnode);
-void v4l2_fwnode_endpoint_free(struct v4l2_fwnode_endpoint *vep);
+
+/**
+ * v4l2_fwnode_parse_link() - parse a link between two endpoints
+ * @fwnode: pointer to the endpoint's fwnode at the local end of the link
+ * @link: pointer to the V4L2 fwnode link data structure
+ *
+ * Fill the link structure with the local and remote nodes and port numbers.
+ * The local_node and remote_node fields are set to point to the local and
+ * remote port's parent nodes respectively (the port parent node being the
+ * parent node of the port node if that node isn't a 'ports' node, or the
+ * grand-parent node of the port node otherwise).
+ *
+ * A reference is taken to both the local and remote nodes, the caller must use
+ * v4l2_fwnode_put_link() to drop the references when done with the
+ * link.
+ *
+ * Return: 0 on success, or -ENOLINK if the remote endpoint fwnode can't be
+ * found.
+ */
 int v4l2_fwnode_parse_link(struct fwnode_handle *fwnode,
 			   struct v4l2_fwnode_link *link);
+
+/**
+ * v4l2_fwnode_put_link() - drop references to nodes in a link
+ * @link: pointer to the V4L2 fwnode link data structure
+ *
+ * Drop references to the local and remote nodes in the link. This function
+ * must be called on every link parsed with v4l2_fwnode_parse_link().
+ */
 void v4l2_fwnode_put_link(struct v4l2_fwnode_link *link);
 
 /**
-- 
2.11.0

Re: [PATCH v15 28/32] smiapp: Add support for flash and lens devices

[Pavel Machek]

[-- Attachment #1: Type: text/plain, Size: 865 bytes --]

On Thu 2017-10-05 00:50:47, Sakari Ailus wrote:
> Parse async sub-devices related to the sensor by switching the async
> sub-device registration function.
> 
> These types devices aren't directly related to the sensor, but are
> nevertheless handled by the smiapp driver due to the relationship of these
> component to the main part of the camera module --- the sensor.
> 
> This does not yet address providing the user space with information on how
> to associate the sensor or lens devices but the kernel now has the
> necessary information to do that.
> 
> Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
> Acked-by: Hans Verkuil <hans.verkuil@cisco.com>

Acked-by: Pavel Machek <pavel@ucw.cz>

-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

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Re: [PATCH v15 29/32] et8ek8: Add support for flash and lens devices

[Pavel Machek]

[-- Attachment #1: Type: text/plain, Size: 457 bytes --]

On Thu 2017-10-05 00:50:48, Sakari Ailus wrote:
> Parse async sub-devices related to the sensor by switching the async
> sub-device registration function.
> 
> Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
> Acked-by: Hans Verkuil <hans.verkuil@cisco.com>

Acked-by: Pavel Machek <pavel@ucw.cz>

-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

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Re: [PATCH v15 01/32] v4l: async: Remove re-probing support

[Sebastian Reichel]

[-- Attachment #1: Type: text/plain, Size: 3481 bytes --]

Hi,

On Thu, Oct 05, 2017 at 12:50:20AM +0300, Sakari Ailus wrote:
> Remove V4L2 async re-probing support. The re-probing support has been
> there to support cases where the sub-devices require resources provided by
> the main driver's hardware to function, such as clocks.
> 
> Reprobing has allowed unbinding and again binding the main driver without
> explicilty unbinding the sub-device drivers. This is certainly not a
> common need, and the responsibility will be the user's going forward.
> 
> An alternative could have been to introduce notifier specific locks.
> Considering the complexity of the re-probing and that it isn't really a
> solution to a problem but a workaround, remove re-probing instead.
> 
> Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
> Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
> Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> ---

Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>

-- Sebastian

>  drivers/media/v4l2-core/v4l2-async.c | 54 +-----------------------------------
>  1 file changed, 1 insertion(+), 53 deletions(-)
> 
> diff --git a/drivers/media/v4l2-core/v4l2-async.c b/drivers/media/v4l2-core/v4l2-async.c
> index d741a8e0fdac..60a1a50b9537 100644
> --- a/drivers/media/v4l2-core/v4l2-async.c
> +++ b/drivers/media/v4l2-core/v4l2-async.c
> @@ -198,78 +198,26 @@ EXPORT_SYMBOL(v4l2_async_notifier_register);
>  void v4l2_async_notifier_unregister(struct v4l2_async_notifier *notifier)
>  {
>  	struct v4l2_subdev *sd, *tmp;
> -	unsigned int notif_n_subdev = notifier->num_subdevs;
> -	unsigned int n_subdev = min(notif_n_subdev, V4L2_MAX_SUBDEVS);
> -	struct device **dev;
> -	int i = 0;
>  
>  	if (!notifier->v4l2_dev)
>  		return;
>  
> -	dev = kvmalloc_array(n_subdev, sizeof(*dev), GFP_KERNEL);
> -	if (!dev) {
> -		dev_err(notifier->v4l2_dev->dev,
> -			"Failed to allocate device cache!\n");
> -	}
> -
>  	mutex_lock(&list_lock);
>  
>  	list_del(&notifier->list);
>  
>  	list_for_each_entry_safe(sd, tmp, &notifier->done, async_list) {
> -		struct device *d;
> -
> -		d = get_device(sd->dev);
> -
>  		v4l2_async_cleanup(sd);
>  
> -		/* If we handled USB devices, we'd have to lock the parent too */
> -		device_release_driver(d);
> -
>  		if (notifier->unbind)
>  			notifier->unbind(notifier, sd, sd->asd);
>  
> -		/*
> -		 * Store device at the device cache, in order to call
> -		 * put_device() on the final step
> -		 */
> -		if (dev)
> -			dev[i++] = d;
> -		else
> -			put_device(d);
> +		list_move(&sd->async_list, &subdev_list);
>  	}
>  
>  	mutex_unlock(&list_lock);
>  
> -	/*
> -	 * Call device_attach() to reprobe devices
> -	 *
> -	 * NOTE: If dev allocation fails, i is 0, and the whole loop won't be
> -	 * executed.
> -	 */
> -	while (i--) {
> -		struct device *d = dev[i];
> -
> -		if (d && device_attach(d) < 0) {
> -			const char *name = "(none)";
> -			int lock = device_trylock(d);
> -
> -			if (lock && d->driver)
> -				name = d->driver->name;
> -			dev_err(d, "Failed to re-probe to %s\n", name);
> -			if (lock)
> -				device_unlock(d);
> -		}
> -		put_device(d);
> -	}
> -	kvfree(dev);
> -
>  	notifier->v4l2_dev = NULL;
> -
> -	/*
> -	 * Don't care about the waiting list, it is initialised and populated
> -	 * upon notifier registration.
> -	 */
>  }
>  EXPORT_SYMBOL(v4l2_async_notifier_unregister);
>  
> -- 
> 2.11.0
> 

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Re: [PATCH v15 02/32] v4l: async: Don't set sd->dev NULL in v4l2_async_cleanup

[Sebastian Reichel]

[-- Attachment #1: Type: text/plain, Size: 1088 bytes --]

Hi,

On Thu, Oct 05, 2017 at 12:50:21AM +0300, Sakari Ailus wrote:
> v4l2_async_cleanup() is called when the async sub-device is unbound from
> the media device. As the pointer is set by the driver registering the
> async sub-device, leave the pointer as set by the driver.
> 
> Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
> ---

Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>

-- Sebastian

>  drivers/media/v4l2-core/v4l2-async.c | 1 -
>  1 file changed, 1 deletion(-)
> 
> diff --git a/drivers/media/v4l2-core/v4l2-async.c b/drivers/media/v4l2-core/v4l2-async.c
> index 60a1a50b9537..21c748bf3a7b 100644
> --- a/drivers/media/v4l2-core/v4l2-async.c
> +++ b/drivers/media/v4l2-core/v4l2-async.c
> @@ -134,7 +134,6 @@ static void v4l2_async_cleanup(struct v4l2_subdev *sd)
>  	/* Subdevice driver will reprobe and put the subdev back onto the list */
>  	list_del_init(&sd->async_list);
>  	sd->asd = NULL;
> -	sd->dev = NULL;
>  }
>  
>  int v4l2_async_notifier_register(struct v4l2_device *v4l2_dev,
> -- 
> 2.11.0
> 

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Re: [PATCH v15 03/32] v4l: async: fix unbind error in v4l2_async_notifier_unregister()

[Sebastian Reichel]

[-- Attachment #1: Type: text/plain, Size: 1757 bytes --]

Hi,

On Thu, Oct 05, 2017 at 12:50:22AM +0300, Sakari Ailus wrote:
> From: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
> 
> The call to v4l2_async_cleanup() will set sd->asd to NULL so passing it to
> notifier->unbind() have no effect and leaves the notifier confused. Call
> the unbind() callback prior to cleaning up the subdevice to avoid this.
> 
> Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
> Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>

Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>

-- Sebastian

> ---
>  drivers/media/v4l2-core/v4l2-async.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/media/v4l2-core/v4l2-async.c b/drivers/media/v4l2-core/v4l2-async.c
> index 21c748bf3a7b..ca281438a0ae 100644
> --- a/drivers/media/v4l2-core/v4l2-async.c
> +++ b/drivers/media/v4l2-core/v4l2-async.c
> @@ -206,11 +206,11 @@ void v4l2_async_notifier_unregister(struct v4l2_async_notifier *notifier)
>  	list_del(&notifier->list);
>  
>  	list_for_each_entry_safe(sd, tmp, &notifier->done, async_list) {
> -		v4l2_async_cleanup(sd);
> -
>  		if (notifier->unbind)
>  			notifier->unbind(notifier, sd, sd->asd);
>  
> +		v4l2_async_cleanup(sd);
> +
>  		list_move(&sd->async_list, &subdev_list);
>  	}
>  
> @@ -268,11 +268,11 @@ void v4l2_async_unregister_subdev(struct v4l2_subdev *sd)
>  
>  	list_add(&sd->asd->list, &notifier->waiting);
>  
> -	v4l2_async_cleanup(sd);
> -
>  	if (notifier->unbind)
>  		notifier->unbind(notifier, sd, sd->asd);
>  
> +	v4l2_async_cleanup(sd);
> +
>  	mutex_unlock(&list_lock);
>  }
>  EXPORT_SYMBOL(v4l2_async_unregister_subdev);
> -- 
> 2.11.0
> 

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Re: [PATCH v15 05/32] v4l: async: Correctly serialise async sub-device unregistration

[Sebastian Reichel]

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Hi,

On Thu, Oct 05, 2017 at 12:50:24AM +0300, Sakari Ailus wrote:
> The check whether an async sub-device is bound to a notifier was performed
> without list_lock held, making it possible for another process to
> unbind the async sub-device before the sub-device unregistration function
> proceeds to take the lock.
> 
> Fix this by first acquiring the lock and then proceeding with the check.
> 
> Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>

Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>

-- Sebastian

> ---
>  drivers/media/v4l2-core/v4l2-async.c | 18 +++++++-----------
>  1 file changed, 7 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/media/v4l2-core/v4l2-async.c b/drivers/media/v4l2-core/v4l2-async.c
> index 4924481451ca..cde2cf2ab4b0 100644
> --- a/drivers/media/v4l2-core/v4l2-async.c
> +++ b/drivers/media/v4l2-core/v4l2-async.c
> @@ -298,20 +298,16 @@ EXPORT_SYMBOL(v4l2_async_register_subdev);
>  
>  void v4l2_async_unregister_subdev(struct v4l2_subdev *sd)
>  {
> -	struct v4l2_async_notifier *notifier = sd->notifier;
> -
> -	if (!sd->asd) {
> -		if (!list_empty(&sd->async_list))
> -			v4l2_async_cleanup(sd);
> -		return;
> -	}
> -
>  	mutex_lock(&list_lock);
>  
> -	list_add(&sd->asd->list, &notifier->waiting);
> +	if (sd->asd) {
> +		struct v4l2_async_notifier *notifier = sd->notifier;
>  
> -	if (notifier->unbind)
> -		notifier->unbind(notifier, sd, sd->asd);
> +		list_add(&sd->asd->list, &notifier->waiting);
> +
> +		if (notifier->unbind)
> +			notifier->unbind(notifier, sd, sd->asd);
> +	}
>  
>  	v4l2_async_cleanup(sd);
>  
> -- 
> 2.11.0
> 

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Re: [PATCH v15 06/32] v4l: async: Use more intuitive names for internal functions

[Sebastian Reichel]

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Hi,

On Thu, Oct 05, 2017 at 12:50:25AM +0300, Sakari Ailus wrote:
> Rename internal functions to make the names of the functions better
> describe what they do.
> 
> 	Old name			New name
> 	v4l2_async_test_notify	v4l2_async_match_notify
> 	v4l2_async_belongs	v4l2_async_find_match
> 
> Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
> Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
> Acked-by: Pavel Machek <pavel@ucw.cz>
> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>

-- Sebastian

> ---
>  drivers/media/v4l2-core/v4l2-async.c | 19 ++++++++++---------
>  1 file changed, 10 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/media/v4l2-core/v4l2-async.c b/drivers/media/v4l2-core/v4l2-async.c
> index cde2cf2ab4b0..8b84fea50c2a 100644
> --- a/drivers/media/v4l2-core/v4l2-async.c
> +++ b/drivers/media/v4l2-core/v4l2-async.c
> @@ -60,8 +60,8 @@ static LIST_HEAD(subdev_list);
>  static LIST_HEAD(notifier_list);
>  static DEFINE_MUTEX(list_lock);
>  
> -static struct v4l2_async_subdev *v4l2_async_belongs(struct v4l2_async_notifier *notifier,
> -						    struct v4l2_subdev *sd)
> +static struct v4l2_async_subdev *v4l2_async_find_match(
> +	struct v4l2_async_notifier *notifier, struct v4l2_subdev *sd)
>  {
>  	bool (*match)(struct v4l2_subdev *, struct v4l2_async_subdev *);
>  	struct v4l2_async_subdev *asd;
> @@ -95,9 +95,9 @@ static struct v4l2_async_subdev *v4l2_async_belongs(struct v4l2_async_notifier *
>  	return NULL;
>  }
>  
> -static int v4l2_async_test_notify(struct v4l2_async_notifier *notifier,
> -				  struct v4l2_subdev *sd,
> -				  struct v4l2_async_subdev *asd)
> +static int v4l2_async_match_notify(struct v4l2_async_notifier *notifier,
> +				   struct v4l2_subdev *sd,
> +				   struct v4l2_async_subdev *asd)
>  {
>  	int ret;
>  
> @@ -187,11 +187,11 @@ int v4l2_async_notifier_register(struct v4l2_device *v4l2_dev,
>  	list_for_each_entry_safe(sd, tmp, &subdev_list, async_list) {
>  		int ret;
>  
> -		asd = v4l2_async_belongs(notifier, sd);
> +		asd = v4l2_async_find_match(notifier, sd);
>  		if (!asd)
>  			continue;
>  
> -		ret = v4l2_async_test_notify(notifier, sd, asd);
> +		ret = v4l2_async_match_notify(notifier, sd, asd);
>  		if (ret < 0) {
>  			mutex_unlock(&list_lock);
>  			return ret;
> @@ -255,13 +255,14 @@ int v4l2_async_register_subdev(struct v4l2_subdev *sd)
>  	INIT_LIST_HEAD(&sd->async_list);
>  
>  	list_for_each_entry(notifier, &notifier_list, list) {
> -		struct v4l2_async_subdev *asd = v4l2_async_belongs(notifier, sd);
> +		struct v4l2_async_subdev *asd = v4l2_async_find_match(notifier,
> +								      sd);
>  		int ret;
>  
>  		if (!asd)
>  			continue;
>  
> -		ret = v4l2_async_test_notify(notifier, sd, asd);
> +		ret = v4l2_async_match_notify(notifier, sd, asd);
>  		if (ret)
>  			goto err_unlock;
>  
> -- 
> 2.11.0
> 

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Re: [PATCH v15 07/32] v4l: async: Add V4L2 async documentation to the documentation build

[Sebastian Reichel]

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Hi,

On Thu, Oct 05, 2017 at 12:50:26AM +0300, Sakari Ailus wrote:
> The V4L2 async wasn't part of the documentation build. Fix this.
> 
> Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
> Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
> Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>

-- Sebastian

> ---
>  Documentation/media/kapi/v4l2-async.rst | 3 +++
>  Documentation/media/kapi/v4l2-core.rst  | 1 +
>  2 files changed, 4 insertions(+)
>  create mode 100644 Documentation/media/kapi/v4l2-async.rst
> 
> diff --git a/Documentation/media/kapi/v4l2-async.rst b/Documentation/media/kapi/v4l2-async.rst
> new file mode 100644
> index 000000000000..523ff9eb09a0
> --- /dev/null
> +++ b/Documentation/media/kapi/v4l2-async.rst
> @@ -0,0 +1,3 @@
> +V4L2 async kAPI
> +^^^^^^^^^^^^^^^
> +.. kernel-doc:: include/media/v4l2-async.h
> diff --git a/Documentation/media/kapi/v4l2-core.rst b/Documentation/media/kapi/v4l2-core.rst
> index c7434f38fd9c..5cf292037a48 100644
> --- a/Documentation/media/kapi/v4l2-core.rst
> +++ b/Documentation/media/kapi/v4l2-core.rst
> @@ -19,6 +19,7 @@ Video4Linux devices
>      v4l2-mc
>      v4l2-mediabus
>      v4l2-mem2mem
> +    v4l2-async
>      v4l2-fwnode
>      v4l2-rect
>      v4l2-tuner
> -- 
> 2.11.0
> 

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Re: [PATCH v15 02/32] v4l: async: Don't set sd->dev NULL in v4l2_async_cleanup

[Hans Verkuil]

On 04/10/17 23:50, Sakari Ailus wrote:
> v4l2_async_cleanup() is called when the async sub-device is unbound from
> the media device. As the pointer is set by the driver registering the
> async sub-device, leave the pointer as set by the driver.
> 
> Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>

Acked-by: Hans Verkuil <hans.verkuil@cisco.com>

> ---
>  drivers/media/v4l2-core/v4l2-async.c | 1 -
>  1 file changed, 1 deletion(-)
> 
> diff --git a/drivers/media/v4l2-core/v4l2-async.c b/drivers/media/v4l2-core/v4l2-async.c
> index 60a1a50b9537..21c748bf3a7b 100644
> --- a/drivers/media/v4l2-core/v4l2-async.c
> +++ b/drivers/media/v4l2-core/v4l2-async.c
> @@ -134,7 +134,6 @@ static void v4l2_async_cleanup(struct v4l2_subdev *sd)
>  	/* Subdevice driver will reprobe and put the subdev back onto the list */
>  	list_del_init(&sd->async_list);
>  	sd->asd = NULL;
> -	sd->dev = NULL;
>  }
>  
>  int v4l2_async_notifier_register(struct v4l2_device *v4l2_dev,
> 

Re: [PATCH v15 01/32] v4l: async: Remove re-probing support

[Mauro Carvalho Chehab]

Em Thu,  5 Oct 2017 00:50:20 +0300
Sakari Ailus <sakari.ailus@linux.intel.com> escreveu:

> Remove V4L2 async re-probing support. The re-probing support has been
> there to support cases where the sub-devices require resources provided by
> the main driver's hardware to function, such as clocks.
> 
> Reprobing has allowed unbinding and again binding the main driver without
> explicilty unbinding the sub-device drivers. This is certainly not a
> common need, and the responsibility will be the user's going forward.
> 
> An alternative could have been to introduce notifier specific locks.
> Considering the complexity of the re-probing and that it isn't really a
> solution to a problem but a workaround, remove re-probing instead.

If the re-probing isn't using anywhere, that sounds a nice cleanup.
Did you check if this won't break any driver (like soc_camera)?

If not, then Acked-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

> 
> Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
> Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
> Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> ---
>  drivers/media/v4l2-core/v4l2-async.c | 54 +-----------------------------------
>  1 file changed, 1 insertion(+), 53 deletions(-)
> 
> diff --git a/drivers/media/v4l2-core/v4l2-async.c b/drivers/media/v4l2-core/v4l2-async.c
> index d741a8e0fdac..60a1a50b9537 100644
> --- a/drivers/media/v4l2-core/v4l2-async.c
> +++ b/drivers/media/v4l2-core/v4l2-async.c
> @@ -198,78 +198,26 @@ EXPORT_SYMBOL(v4l2_async_notifier_register);
>  void v4l2_async_notifier_unregister(struct v4l2_async_notifier *notifier)
>  {
>  	struct v4l2_subdev *sd, *tmp;
> -	unsigned int notif_n_subdev = notifier->num_subdevs;
> -	unsigned int n_subdev = min(notif_n_subdev, V4L2_MAX_SUBDEVS);
> -	struct device **dev;
> -	int i = 0;
>  
>  	if (!notifier->v4l2_dev)
>  		return;
>  
> -	dev = kvmalloc_array(n_subdev, sizeof(*dev), GFP_KERNEL);
> -	if (!dev) {
> -		dev_err(notifier->v4l2_dev->dev,
> -			"Failed to allocate device cache!\n");
> -	}
> -
>  	mutex_lock(&list_lock);
>  
>  	list_del(&notifier->list);
>  
>  	list_for_each_entry_safe(sd, tmp, &notifier->done, async_list) {
> -		struct device *d;
> -
> -		d = get_device(sd->dev);
> -
>  		v4l2_async_cleanup(sd);
>  
> -		/* If we handled USB devices, we'd have to lock the parent too */
> -		device_release_driver(d);
> -
>  		if (notifier->unbind)
>  			notifier->unbind(notifier, sd, sd->asd);
>  
> -		/*
> -		 * Store device at the device cache, in order to call
> -		 * put_device() on the final step
> -		 */
> -		if (dev)
> -			dev[i++] = d;
> -		else
> -			put_device(d);
> +		list_move(&sd->async_list, &subdev_list);
>  	}
>  
>  	mutex_unlock(&list_lock);
>  
> -	/*
> -	 * Call device_attach() to reprobe devices
> -	 *
> -	 * NOTE: If dev allocation fails, i is 0, and the whole loop won't be
> -	 * executed.
> -	 */
> -	while (i--) {
> -		struct device *d = dev[i];
> -
> -		if (d && device_attach(d) < 0) {
> -			const char *name = "(none)";
> -			int lock = device_trylock(d);
> -
> -			if (lock && d->driver)
> -				name = d->driver->name;
> -			dev_err(d, "Failed to re-probe to %s\n", name);
> -			if (lock)
> -				device_unlock(d);
> -		}
> -		put_device(d);
> -	}
> -	kvfree(dev);
> -
>  	notifier->v4l2_dev = NULL;
> -
> -	/*
> -	 * Don't care about the waiting list, it is initialised and populated
> -	 * upon notifier registration.
> -	 */
>  }
>  EXPORT_SYMBOL(v4l2_async_notifier_unregister);
>  



Thanks,
Mauro

Re: [PATCH v15 03/32] v4l: async: fix unbind error in v4l2_async_notifier_unregister()

[Hans Verkuil]

On 04/10/17 23:50, Sakari Ailus wrote:
> From: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
> 
> The call to v4l2_async_cleanup() will set sd->asd to NULL so passing it to
> notifier->unbind() have no effect and leaves the notifier confused. Call

have -> has

> the unbind() callback prior to cleaning up the subdevice to avoid this.
> 
> Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
> Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>

After fixing this small typo:

Acked-by: Hans Verkuil <hans.verkuil@cisco.com>

> ---
>  drivers/media/v4l2-core/v4l2-async.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/media/v4l2-core/v4l2-async.c b/drivers/media/v4l2-core/v4l2-async.c
> index 21c748bf3a7b..ca281438a0ae 100644
> --- a/drivers/media/v4l2-core/v4l2-async.c
> +++ b/drivers/media/v4l2-core/v4l2-async.c
> @@ -206,11 +206,11 @@ void v4l2_async_notifier_unregister(struct v4l2_async_notifier *notifier)
>  	list_del(&notifier->list);
>  
>  	list_for_each_entry_safe(sd, tmp, &notifier->done, async_list) {
> -		v4l2_async_cleanup(sd);
> -
>  		if (notifier->unbind)
>  			notifier->unbind(notifier, sd, sd->asd);
>  
> +		v4l2_async_cleanup(sd);
> +
>  		list_move(&sd->async_list, &subdev_list);
>  	}
>  
> @@ -268,11 +268,11 @@ void v4l2_async_unregister_subdev(struct v4l2_subdev *sd)
>  
>  	list_add(&sd->asd->list, &notifier->waiting);
>  
> -	v4l2_async_cleanup(sd);
> -
>  	if (notifier->unbind)
>  		notifier->unbind(notifier, sd, sd->asd);
>  
> +	v4l2_async_cleanup(sd);
> +
>  	mutex_unlock(&list_lock);
>  }
>  EXPORT_SYMBOL(v4l2_async_unregister_subdev);
> 

Re: [PATCH v15 07/32] v4l: async: Add V4L2 async documentation to the documentation build

[Mauro Carvalho Chehab]

Em Thu,  5 Oct 2017 00:50:26 +0300
Sakari Ailus <sakari.ailus@linux.intel.com> escreveu:

> The V4L2 async wasn't part of the documentation build. Fix this.
> 
> Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
> Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
> Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

Reviewed-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

It doesn't make sense to keep rebasing this patch or to delay
merging it: just add it at the next git pull request you send me,
as this is actually independent of the rest :-)


> ---
>  Documentation/media/kapi/v4l2-async.rst | 3 +++
>  Documentation/media/kapi/v4l2-core.rst  | 1 +
>  2 files changed, 4 insertions(+)
>  create mode 100644 Documentation/media/kapi/v4l2-async.rst
> 
> diff --git a/Documentation/media/kapi/v4l2-async.rst b/Documentation/media/kapi/v4l2-async.rst
> new file mode 100644
> index 000000000000..523ff9eb09a0
> --- /dev/null
> +++ b/Documentation/media/kapi/v4l2-async.rst
> @@ -0,0 +1,3 @@
> +V4L2 async kAPI
> +^^^^^^^^^^^^^^^
> +.. kernel-doc:: include/media/v4l2-async.h
> diff --git a/Documentation/media/kapi/v4l2-core.rst b/Documentation/media/kapi/v4l2-core.rst
> index c7434f38fd9c..5cf292037a48 100644
> --- a/Documentation/media/kapi/v4l2-core.rst
> +++ b/Documentation/media/kapi/v4l2-core.rst
> @@ -19,6 +19,7 @@ Video4Linux devices
>      v4l2-mc
>      v4l2-mediabus
>      v4l2-mem2mem
> +    v4l2-async
>      v4l2-fwnode
>      v4l2-rect
>      v4l2-tuner



Thanks,
Mauro

Re: [PATCH v15 05/32] v4l: async: Correctly serialise async sub-device unregistration

[Hans Verkuil]

On 04/10/17 23:50, Sakari Ailus wrote:
> The check whether an async sub-device is bound to a notifier was performed
> without list_lock held, making it possible for another process to
> unbind the async sub-device before the sub-device unregistration function
> proceeds to take the lock.
> 
> Fix this by first acquiring the lock and then proceeding with the check.
> 
> Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>

Acked-by: Hans Verkuil <hans.verkuil@cisco.com>

> ---
>  drivers/media/v4l2-core/v4l2-async.c | 18 +++++++-----------
>  1 file changed, 7 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/media/v4l2-core/v4l2-async.c b/drivers/media/v4l2-core/v4l2-async.c
> index 4924481451ca..cde2cf2ab4b0 100644
> --- a/drivers/media/v4l2-core/v4l2-async.c
> +++ b/drivers/media/v4l2-core/v4l2-async.c
> @@ -298,20 +298,16 @@ EXPORT_SYMBOL(v4l2_async_register_subdev);
>  
>  void v4l2_async_unregister_subdev(struct v4l2_subdev *sd)
>  {
> -	struct v4l2_async_notifier *notifier = sd->notifier;
> -
> -	if (!sd->asd) {
> -		if (!list_empty(&sd->async_list))
> -			v4l2_async_cleanup(sd);
> -		return;
> -	}
> -
>  	mutex_lock(&list_lock);
>  
> -	list_add(&sd->asd->list, &notifier->waiting);
> +	if (sd->asd) {
> +		struct v4l2_async_notifier *notifier = sd->notifier;
>  
> -	if (notifier->unbind)
> -		notifier->unbind(notifier, sd, sd->asd);
> +		list_add(&sd->asd->list, &notifier->waiting);
> +
> +		if (notifier->unbind)
> +			notifier->unbind(notifier, sd, sd->asd);
> +	}
>  
>  	v4l2_async_cleanup(sd);
>  
> 

Re: [PATCH v15 04/32] v4l: async: Fix notifier complete callback error handling

[Hans Verkuil]

On 04/10/17 23:50, Sakari Ailus wrote:
> The notifier complete callback may return an error. This error code was
> simply returned to the caller but never handled properly.
> 
> Move calling the complete callback function to the caller from
> v4l2_async_test_notify and undo the work that was done either in async
> sub-device or async notifier registration.
> 
> Reported-by: Russell King <rmk+kernel@armlinux.org.uk>
> Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
> ---
>  drivers/media/v4l2-core/v4l2-async.c | 78 +++++++++++++++++++++++++++---------
>  1 file changed, 60 insertions(+), 18 deletions(-)
> 
> diff --git a/drivers/media/v4l2-core/v4l2-async.c b/drivers/media/v4l2-core/v4l2-async.c
> index ca281438a0ae..4924481451ca 100644
> --- a/drivers/media/v4l2-core/v4l2-async.c
> +++ b/drivers/media/v4l2-core/v4l2-async.c
> @@ -122,9 +122,6 @@ static int v4l2_async_test_notify(struct v4l2_async_notifier *notifier,
>  	/* Move from the global subdevice list to notifier's done */
>  	list_move(&sd->async_list, &notifier->done);
>  
> -	if (list_empty(&notifier->waiting) && notifier->complete)
> -		return notifier->complete(notifier);
> -
>  	return 0;
>  }
>  
> @@ -136,11 +133,27 @@ static void v4l2_async_cleanup(struct v4l2_subdev *sd)
>  	sd->asd = NULL;
>  }
>  
> +static void v4l2_async_notifier_unbind_all_subdevs(
> +	struct v4l2_async_notifier *notifier)
> +{
> +	struct v4l2_subdev *sd, *tmp;
> +
> +	list_for_each_entry_safe(sd, tmp, &notifier->done, async_list) {
> +		if (notifier->unbind)
> +			notifier->unbind(notifier, sd, sd->asd);
> +
> +		v4l2_async_cleanup(sd);
> +
> +		list_move(&sd->async_list, &subdev_list);
> +	}
> +}
> +
>  int v4l2_async_notifier_register(struct v4l2_device *v4l2_dev,
>  				 struct v4l2_async_notifier *notifier)
>  {
>  	struct v4l2_subdev *sd, *tmp;
>  	struct v4l2_async_subdev *asd;
> +	int ret;
>  	int i;
>  
>  	if (!v4l2_dev || !notifier->num_subdevs ||
> @@ -185,19 +198,30 @@ int v4l2_async_notifier_register(struct v4l2_device *v4l2_dev,
>  		}
>  	}
>  
> +	if (list_empty(&notifier->waiting) && notifier->complete) {
> +		ret = notifier->complete(notifier);
> +		if (ret)
> +			goto err_complete;
> +	}
> +
>  	/* Keep also completed notifiers on the list */
>  	list_add(&notifier->list, &notifier_list);
>  
>  	mutex_unlock(&list_lock);
>  
>  	return 0;
> +
> +err_complete:
> +	v4l2_async_notifier_unbind_all_subdevs(notifier);
> +
> +	mutex_unlock(&list_lock);
> +
> +	return ret;
>  }
>  EXPORT_SYMBOL(v4l2_async_notifier_register);
>  
>  void v4l2_async_notifier_unregister(struct v4l2_async_notifier *notifier)
>  {
> -	struct v4l2_subdev *sd, *tmp;
> -
>  	if (!notifier->v4l2_dev)
>  		return;
>  
> @@ -205,14 +229,7 @@ void v4l2_async_notifier_unregister(struct v4l2_async_notifier *notifier)
>  
>  	list_del(&notifier->list);
>  
> -	list_for_each_entry_safe(sd, tmp, &notifier->done, async_list) {
> -		if (notifier->unbind)
> -			notifier->unbind(notifier, sd, sd->asd);
> -
> -		v4l2_async_cleanup(sd);
> -
> -		list_move(&sd->async_list, &subdev_list);
> -	}
> +	v4l2_async_notifier_unbind_all_subdevs(notifier);
>  
>  	mutex_unlock(&list_lock);
>  
> @@ -223,6 +240,7 @@ EXPORT_SYMBOL(v4l2_async_notifier_unregister);
>  int v4l2_async_register_subdev(struct v4l2_subdev *sd)
>  {
>  	struct v4l2_async_notifier *notifier;
> +	int ret;
>  
>  	/*
>  	 * No reference taken. The reference is held by the device
> @@ -238,19 +256,43 @@ int v4l2_async_register_subdev(struct v4l2_subdev *sd)
>  
>  	list_for_each_entry(notifier, &notifier_list, list) {
>  		struct v4l2_async_subdev *asd = v4l2_async_belongs(notifier, sd);
> -		if (asd) {
> -			int ret = v4l2_async_test_notify(notifier, sd, asd);
> -			mutex_unlock(&list_lock);
> -			return ret;
> -		}
> +		int ret;
> +
> +		if (!asd)
> +			continue;
> +
> +		ret = v4l2_async_test_notify(notifier, sd, asd);
> +		if (ret)
> +			goto err_unlock;
> +
> +		if (!list_empty(&notifier->waiting) || !notifier->complete)
> +			goto out_unlock;
> +
> +		ret = notifier->complete(notifier);
> +		if (ret)
> +			goto err_cleanup;
> +
> +		goto out_unlock;
>  	}
>  
>  	/* None matched, wait for hot-plugging */
>  	list_add(&sd->async_list, &subdev_list);
>  
> +out_unlock:
>  	mutex_unlock(&list_lock);
>  
>  	return 0;
> +
> +err_cleanup:
> +	if (notifier->unbind)
> +		notifier->unbind(notifier, sd, sd->asd);
> +
> +	v4l2_async_cleanup(sd);

I'm trying to understand this. Who will unbind all subdevs in this case?

And in the general case: if complete returns an error, the bridge driver
should be remove()d. Who will do that? Does that work at all?

Regards,

	Hans

> +
> +err_unlock:
> +	mutex_unlock(&list_lock);
> +
> +	return ret;
>  }
>  EXPORT_SYMBOL(v4l2_async_register_subdev);
>  
> 

Re: [PATCH v15 01/32] v4l: async: Remove re-probing support

[Sakari Ailus]

Hi Mauro,

On Mon, Oct 09, 2017 at 08:22:39AM -0300, Mauro Carvalho Chehab wrote:
> Em Thu,  5 Oct 2017 00:50:20 +0300
> Sakari Ailus <sakari.ailus@linux.intel.com> escreveu:
> 
> > Remove V4L2 async re-probing support. The re-probing support has been
> > there to support cases where the sub-devices require resources provided by
> > the main driver's hardware to function, such as clocks.
> > 
> > Reprobing has allowed unbinding and again binding the main driver without
> > explicilty unbinding the sub-device drivers. This is certainly not a
> > common need, and the responsibility will be the user's going forward.
> > 
> > An alternative could have been to introduce notifier specific locks.
> > Considering the complexity of the re-probing and that it isn't really a
> > solution to a problem but a workaround, remove re-probing instead.
> 
> If the re-probing isn't using anywhere, that sounds a nice cleanup.
> Did you check if this won't break any driver (like soc_camera)?

That was discussed earlier in the review; Laurent asked the same question.

Re-probing never was a proper solution to any problem; it was just a hack
to avoid unbinding the sensor if the bridge driver was unbound, no more: it
can't be generalised to support more complex use cases. Mind you, this is
on devices that aren't actually removable.

I've briefly discussed this with Laurent; the proper solution would need to
be implemented in the clock framework instead. There, the existing clocks
obtained by drivers could be re-activated when the driver for them comes
back.

My proposal is that if there's real a need to address this, then it could
be solved in the clock framework.

-- 
Kind regards,

Sakari Ailus
e-mail: sakari.ailus@iki.fi

Re: [PATCH v15 01/32] v4l: async: Remove re-probing support

[Hans Verkuil]

On 09/10/17 16:06, Sakari Ailus wrote:
> Hi Mauro,
> 
> On Mon, Oct 09, 2017 at 08:22:39AM -0300, Mauro Carvalho Chehab wrote:
>> Em Thu,  5 Oct 2017 00:50:20 +0300
>> Sakari Ailus <sakari.ailus@linux.intel.com> escreveu:
>>
>>> Remove V4L2 async re-probing support. The re-probing support has been
>>> there to support cases where the sub-devices require resources provided by
>>> the main driver's hardware to function, such as clocks.
>>>
>>> Reprobing has allowed unbinding and again binding the main driver without
>>> explicilty unbinding the sub-device drivers. This is certainly not a
>>> common need, and the responsibility will be the user's going forward.
>>>
>>> An alternative could have been to introduce notifier specific locks.
>>> Considering the complexity of the re-probing and that it isn't really a
>>> solution to a problem but a workaround, remove re-probing instead.
>>
>> If the re-probing isn't using anywhere, that sounds a nice cleanup.
>> Did you check if this won't break any driver (like soc_camera)?
> 
> That was discussed earlier in the review; Laurent asked the same question.
> 
> Re-probing never was a proper solution to any problem; it was just a hack
> to avoid unbinding the sensor if the bridge driver was unbound, no more: it
> can't be generalised to support more complex use cases. Mind you, this is
> on devices that aren't actually removable.
> 
> I've briefly discussed this with Laurent; the proper solution would need to
> be implemented in the clock framework instead. There, the existing clocks
> obtained by drivers could be re-activated when the driver for them comes
> back.
> 
> My proposal is that if there's real a need to address this, then it could
> be solved in the clock framework.

Can you add this information to the commit log?

I think that would be very helpful in the future.

Regards,

	Hans

Re: [PATCH v15 01/32] v4l: async: Remove re-probing support

[Sakari Ailus]

Hi Hans,

On Mon, Oct 09, 2017 at 04:08:47PM +0200, Hans Verkuil wrote:
> On 09/10/17 16:06, Sakari Ailus wrote:
> > Hi Mauro,
> > 
> > On Mon, Oct 09, 2017 at 08:22:39AM -0300, Mauro Carvalho Chehab wrote:
> >> Em Thu,  5 Oct 2017 00:50:20 +0300
> >> Sakari Ailus <sakari.ailus@linux.intel.com> escreveu:
> >>
> >>> Remove V4L2 async re-probing support. The re-probing support has been
> >>> there to support cases where the sub-devices require resources provided by
> >>> the main driver's hardware to function, such as clocks.
> >>>
> >>> Reprobing has allowed unbinding and again binding the main driver without
> >>> explicilty unbinding the sub-device drivers. This is certainly not a
> >>> common need, and the responsibility will be the user's going forward.
> >>>
> >>> An alternative could have been to introduce notifier specific locks.
> >>> Considering the complexity of the re-probing and that it isn't really a
> >>> solution to a problem but a workaround, remove re-probing instead.
> >>
> >> If the re-probing isn't using anywhere, that sounds a nice cleanup.
> >> Did you check if this won't break any driver (like soc_camera)?
> > 
> > That was discussed earlier in the review; Laurent asked the same question.
> > 
> > Re-probing never was a proper solution to any problem; it was just a hack
> > to avoid unbinding the sensor if the bridge driver was unbound, no more: it
> > can't be generalised to support more complex use cases. Mind you, this is
> > on devices that aren't actually removable.
> > 
> > I've briefly discussed this with Laurent; the proper solution would need to
> > be implemented in the clock framework instead. There, the existing clocks
> > obtained by drivers could be re-activated when the driver for them comes
> > back.
> > 
> > My proposal is that if there's real a need to address this, then it could
> > be solved in the clock framework.
> 
> Can you add this information to the commit log?
> 
> I think that would be very helpful in the future.

Sure, how about this at the end of the current commit message:

If there is a need to support removing the clock provider in the future,
this should be implemented in the clock framework instead, not in V4L2.

-- 
Regards,

Sakari Ailus
e-mail: sakari.ailus@iki.fi

Re: [PATCH v15 01/32] v4l: async: Remove re-probing support

[Hans Verkuil]

On 09/10/17 16:18, Sakari Ailus wrote:
> Hi Hans,
> 
> On Mon, Oct 09, 2017 at 04:08:47PM +0200, Hans Verkuil wrote:
>> On 09/10/17 16:06, Sakari Ailus wrote:
>>> Hi Mauro,
>>>
>>> On Mon, Oct 09, 2017 at 08:22:39AM -0300, Mauro Carvalho Chehab wrote:
>>>> Em Thu,  5 Oct 2017 00:50:20 +0300
>>>> Sakari Ailus <sakari.ailus@linux.intel.com> escreveu:
>>>>
>>>>> Remove V4L2 async re-probing support. The re-probing support has been
>>>>> there to support cases where the sub-devices require resources provided by
>>>>> the main driver's hardware to function, such as clocks.
>>>>>
>>>>> Reprobing has allowed unbinding and again binding the main driver without
>>>>> explicilty unbinding the sub-device drivers. This is certainly not a
>>>>> common need, and the responsibility will be the user's going forward.
>>>>>
>>>>> An alternative could have been to introduce notifier specific locks.
>>>>> Considering the complexity of the re-probing and that it isn't really a
>>>>> solution to a problem but a workaround, remove re-probing instead.
>>>>
>>>> If the re-probing isn't using anywhere, that sounds a nice cleanup.
>>>> Did you check if this won't break any driver (like soc_camera)?
>>>
>>> That was discussed earlier in the review; Laurent asked the same question.
>>>
>>> Re-probing never was a proper solution to any problem; it was just a hack
>>> to avoid unbinding the sensor if the bridge driver was unbound, no more: it
>>> can't be generalised to support more complex use cases. Mind you, this is
>>> on devices that aren't actually removable.
>>>
>>> I've briefly discussed this with Laurent; the proper solution would need to
>>> be implemented in the clock framework instead. There, the existing clocks
>>> obtained by drivers could be re-activated when the driver for them comes
>>> back.
>>>
>>> My proposal is that if there's real a need to address this, then it could
>>> be solved in the clock framework.
>>
>> Can you add this information to the commit log?
>>
>> I think that would be very helpful in the future.
> 
> Sure, how about this at the end of the current commit message:
> 
> If there is a need to support removing the clock provider in the future,
> this should be implemented in the clock framework instead, not in V4L2.

Yes, that sounds good.

Regards,

	Hans

Re: [PATCH v15 01/32] v4l: async: Remove re-probing support

[Mauro Carvalho Chehab]

Em Mon, 9 Oct 2017 16:20:08 +0200
Hans Verkuil <hverkuil@xs4all.nl> escreveu:

> On 09/10/17 16:18, Sakari Ailus wrote:
> > Hi Hans,
> > 
> > On Mon, Oct 09, 2017 at 04:08:47PM +0200, Hans Verkuil wrote:  
> >> On 09/10/17 16:06, Sakari Ailus wrote:  
> >>> Hi Mauro,
> >>>
> >>> On Mon, Oct 09, 2017 at 08:22:39AM -0300, Mauro Carvalho Chehab wrote:  
> >>>> Em Thu,  5 Oct 2017 00:50:20 +0300
> >>>> Sakari Ailus <sakari.ailus@linux.intel.com> escreveu:
> >>>>  
> >>>>> Remove V4L2 async re-probing support. The re-probing support has been
> >>>>> there to support cases where the sub-devices require resources provided by
> >>>>> the main driver's hardware to function, such as clocks.
> >>>>>
> >>>>> Reprobing has allowed unbinding and again binding the main driver without
> >>>>> explicilty unbinding the sub-device drivers. This is certainly not a
> >>>>> common need, and the responsibility will be the user's going forward.
> >>>>>
> >>>>> An alternative could have been to introduce notifier specific locks.
> >>>>> Considering the complexity of the re-probing and that it isn't really a
> >>>>> solution to a problem but a workaround, remove re-probing instead.  
> >>>>
> >>>> If the re-probing isn't using anywhere, that sounds a nice cleanup.
> >>>> Did you check if this won't break any driver (like soc_camera)?  
> >>>
> >>> That was discussed earlier in the review; Laurent asked the same question.
> >>>
> >>> Re-probing never was a proper solution to any problem; it was just a hack
> >>> to avoid unbinding the sensor if the bridge driver was unbound, no more: it
> >>> can't be generalised to support more complex use cases. Mind you, this is
> >>> on devices that aren't actually removable.
> >>>
> >>> I've briefly discussed this with Laurent; the proper solution would need to
> >>> be implemented in the clock framework instead. There, the existing clocks
> >>> obtained by drivers could be re-activated when the driver for them comes
> >>> back.
> >>>
> >>> My proposal is that if there's real a need to address this, then it could
> >>> be solved in the clock framework.  
> >>
> >> Can you add this information to the commit log?
> >>
> >> I think that would be very helpful in the future.  
> > 
> > Sure, how about this at the end of the current commit message:
> > 
> > If there is a need to support removing the clock provider in the future,
> > this should be implemented in the clock framework instead, not in V4L2.  
> 
> Yes, that sounds good.

Works for me too.

Regards,
Mauro

Re: [PATCH v15 01/32] v4l: async: Remove re-probing support

[Sylwester Nawrocki]

Hi Sakari,

On 10/09/2017 04:18 PM, Sakari Ailus wrote:
> Sure, how about this at the end of the current commit message:
> 
> If there is a need to support removing the clock provider in the future,
> this should be implemented in the clock framework instead, not in V4L2.

I find it a little bit misleading, there is already support for removing
the clock provider, only any clock references for consumers became then
stale.  Perhaps:

"If there is a need to support the clock provider unregister/register 
cycle while keeping the clock references in the consumers in the future, 
this should be implemented in the clock framework instead, not in V4L2."

? That said, I doubt this issue is going to be entirely solved solely 
in the clock framework, as it is a more general problem of resource 
dependencies.  It could be related to other resources, like regulator
or GPIO.  It has been discussed for a long time now and it will likely 
take time until a general solution is available.

--
Thanks, 
Sylwester

Re: [PATCH v15 01/32] v4l: async: Remove re-probing support

[Laurent Pinchart]

Hi Sylwester,

On Monday, 9 October 2017 19:44:52 EEST Sylwester Nawrocki wrote:
> On 10/09/2017 04:18 PM, Sakari Ailus wrote:
> > Sure, how about this at the end of the current commit message:
> > 
> > If there is a need to support removing the clock provider in the future,
> > this should be implemented in the clock framework instead, not in V4L2.
> 
> I find it a little bit misleading, there is already support for removing
> the clock provider, only any clock references for consumers became then
> stale.  Perhaps:
> 
> "If there is a need to support the clock provider unregister/register
> cycle while keeping the clock references in the consumers in the future,
> this should be implemented in the clock framework instead, not in V4L2."
> 
> ? That said, I doubt this issue is going to be entirely solved solely
> in the clock framework, as it is a more general problem of resource
> dependencies.  It could be related to other resources, like regulator
> or GPIO.  It has been discussed for a long time now and it will likely
> take time until a general solution is available.

I discussed this issue with Mike Turquette during LPC, and he believed we 
could fix it in the clock framework by adding support for "un-orphaning" a 
clock. This remains to be proven by a real implementation, but could work for 
our use case.

I agree with you that similar problems exist for other resources such as 
regulators and GPIOs, but to my knowledge we have no system that requires V4L2 
reprobing due to regulator or GPIO dependencies.

-- 
Regards,

Laurent Pinchart

Re: [PATCH v15 01/32] v4l: async: Remove re-probing support

[Sakari Ailus]

Hi Sylwester,

On Mon, Oct 09, 2017 at 06:44:52PM +0200, Sylwester Nawrocki wrote:
> Hi Sakari,
> 
> On 10/09/2017 04:18 PM, Sakari Ailus wrote:
> > Sure, how about this at the end of the current commit message:
> > 
> > If there is a need to support removing the clock provider in the future,
> > this should be implemented in the clock framework instead, not in V4L2.
> 
> I find it a little bit misleading, there is already support for removing
> the clock provider, only any clock references for consumers became then
> stale.  Perhaps:
> 
> "If there is a need to support the clock provider unregister/register 
> cycle while keeping the clock references in the consumers in the future, 
> this should be implemented in the clock framework instead, not in V4L2."

Yes, I'll use this in v16.

> 
> ? That said, I doubt this issue is going to be entirely solved solely 
> in the clock framework, as it is a more general problem of resource 
> dependencies.  It could be related to other resources, like regulator
> or GPIO.  It has been discussed for a long time now and it will likely 
> take time until a general solution is available.

I don't think we can have entirely generic solutions to this as the API
through which the resources are accessed is specific to the resources
(regulator, GPIO, clock). Or the generic solution would be used by the
frameworks behind those APIs. But as Laurent mentioned, we don't have this
case with other than clock currently.

-- 
Regards,

Sakari Ailus
e-mail: sakari.ailus@iki.fi

Re: [PATCH v15 04/32] v4l: async: Fix notifier complete callback error handling

[Sakari Ailus]

Hi Hans,

On Mon, Oct 09, 2017 at 01:45:25PM +0200, Hans Verkuil wrote:
> On 04/10/17 23:50, Sakari Ailus wrote:
> > The notifier complete callback may return an error. This error code was
> > simply returned to the caller but never handled properly.
> > 
> > Move calling the complete callback function to the caller from
> > v4l2_async_test_notify and undo the work that was done either in async
> > sub-device or async notifier registration.
> > 
> > Reported-by: Russell King <rmk+kernel@armlinux.org.uk>
> > Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
> > ---
> >  drivers/media/v4l2-core/v4l2-async.c | 78 +++++++++++++++++++++++++++---------
> >  1 file changed, 60 insertions(+), 18 deletions(-)
> > 
> > diff --git a/drivers/media/v4l2-core/v4l2-async.c b/drivers/media/v4l2-core/v4l2-async.c
> > index ca281438a0ae..4924481451ca 100644
> > --- a/drivers/media/v4l2-core/v4l2-async.c
> > +++ b/drivers/media/v4l2-core/v4l2-async.c
> > @@ -122,9 +122,6 @@ static int v4l2_async_test_notify(struct v4l2_async_notifier *notifier,
> >  	/* Move from the global subdevice list to notifier's done */
> >  	list_move(&sd->async_list, &notifier->done);
> >  
> > -	if (list_empty(&notifier->waiting) && notifier->complete)
> > -		return notifier->complete(notifier);
> > -
> >  	return 0;
> >  }
> >  
> > @@ -136,11 +133,27 @@ static void v4l2_async_cleanup(struct v4l2_subdev *sd)
> >  	sd->asd = NULL;
> >  }
> >  
> > +static void v4l2_async_notifier_unbind_all_subdevs(
> > +	struct v4l2_async_notifier *notifier)
> > +{
> > +	struct v4l2_subdev *sd, *tmp;
> > +
> > +	list_for_each_entry_safe(sd, tmp, &notifier->done, async_list) {
> > +		if (notifier->unbind)
> > +			notifier->unbind(notifier, sd, sd->asd);
> > +
> > +		v4l2_async_cleanup(sd);
> > +
> > +		list_move(&sd->async_list, &subdev_list);
> > +	}
> > +}
> > +
> >  int v4l2_async_notifier_register(struct v4l2_device *v4l2_dev,
> >  				 struct v4l2_async_notifier *notifier)
> >  {
> >  	struct v4l2_subdev *sd, *tmp;
> >  	struct v4l2_async_subdev *asd;
> > +	int ret;
> >  	int i;
> >  
> >  	if (!v4l2_dev || !notifier->num_subdevs ||
> > @@ -185,19 +198,30 @@ int v4l2_async_notifier_register(struct v4l2_device *v4l2_dev,
> >  		}
> >  	}
> >  
> > +	if (list_empty(&notifier->waiting) && notifier->complete) {
> > +		ret = notifier->complete(notifier);
> > +		if (ret)
> > +			goto err_complete;
> > +	}
> > +
> >  	/* Keep also completed notifiers on the list */
> >  	list_add(&notifier->list, &notifier_list);
> >  
> >  	mutex_unlock(&list_lock);
> >  
> >  	return 0;
> > +
> > +err_complete:
> > +	v4l2_async_notifier_unbind_all_subdevs(notifier);
> > +
> > +	mutex_unlock(&list_lock);
> > +
> > +	return ret;
> >  }
> >  EXPORT_SYMBOL(v4l2_async_notifier_register);
> >  
> >  void v4l2_async_notifier_unregister(struct v4l2_async_notifier *notifier)
> >  {
> > -	struct v4l2_subdev *sd, *tmp;
> > -
> >  	if (!notifier->v4l2_dev)
> >  		return;
> >  
> > @@ -205,14 +229,7 @@ void v4l2_async_notifier_unregister(struct v4l2_async_notifier *notifier)
> >  
> >  	list_del(&notifier->list);
> >  
> > -	list_for_each_entry_safe(sd, tmp, &notifier->done, async_list) {
> > -		if (notifier->unbind)
> > -			notifier->unbind(notifier, sd, sd->asd);
> > -
> > -		v4l2_async_cleanup(sd);
> > -
> > -		list_move(&sd->async_list, &subdev_list);
> > -	}
> > +	v4l2_async_notifier_unbind_all_subdevs(notifier);
> >  
> >  	mutex_unlock(&list_lock);
> >  
> > @@ -223,6 +240,7 @@ EXPORT_SYMBOL(v4l2_async_notifier_unregister);
> >  int v4l2_async_register_subdev(struct v4l2_subdev *sd)
> >  {
> >  	struct v4l2_async_notifier *notifier;
> > +	int ret;
> >  
> >  	/*
> >  	 * No reference taken. The reference is held by the device
> > @@ -238,19 +256,43 @@ int v4l2_async_register_subdev(struct v4l2_subdev *sd)
> >  
> >  	list_for_each_entry(notifier, &notifier_list, list) {
> >  		struct v4l2_async_subdev *asd = v4l2_async_belongs(notifier, sd);
> > -		if (asd) {
> > -			int ret = v4l2_async_test_notify(notifier, sd, asd);
> > -			mutex_unlock(&list_lock);
> > -			return ret;
> > -		}
> > +		int ret;
> > +
> > +		if (!asd)
> > +			continue;
> > +
> > +		ret = v4l2_async_test_notify(notifier, sd, asd);
> > +		if (ret)
> > +			goto err_unlock;
> > +
> > +		if (!list_empty(&notifier->waiting) || !notifier->complete)
> > +			goto out_unlock;
> > +
> > +		ret = notifier->complete(notifier);
> > +		if (ret)
> > +			goto err_cleanup;
> > +
> > +		goto out_unlock;
> >  	}
> >  
> >  	/* None matched, wait for hot-plugging */
> >  	list_add(&sd->async_list, &subdev_list);
> >  
> > +out_unlock:
> >  	mutex_unlock(&list_lock);
> >  
> >  	return 0;
> > +
> > +err_cleanup:
> > +	if (notifier->unbind)
> > +		notifier->unbind(notifier, sd, sd->asd);
> > +
> > +	v4l2_async_cleanup(sd);
> 
> I'm trying to understand this. Who will unbind all subdevs in this case?

The driver that registered them is responsible for that, as usual.

> 
> And in the general case: if complete returns an error, the bridge driver
> should be remove()d. Who will do that? Does that work at all?

The bridge driver can't do that alone, the bridge driver would need to be
unbound explicitly by the user.

This approach has the benefit that it's symmetric: on error we only tear
down the part that was added, no more. Doing otherwise would likely make
the error handling hard to understand and test properly. For instance, if a
driver's probe function calling v4l2_async_register_subdev() or
v4l2_async_notifier_register() fails, leading the driver binding to fail.
If the error is temporary for whatever reason, just retrying the operation
will help.

-- 
Kind regards,

Sakari Ailus
e-mail: sakari.ailus@iki.fi

Re: [PATCH v15 04/32] v4l: async: Fix notifier complete callback error handling

[Hans Verkuil]

On 10/10/2017 02:57 PM, Sakari Ailus wrote:
> Hi Hans,
> 
> On Mon, Oct 09, 2017 at 01:45:25PM +0200, Hans Verkuil wrote:
>> On 04/10/17 23:50, Sakari Ailus wrote:
>>> The notifier complete callback may return an error. This error code was
>>> simply returned to the caller but never handled properly.
>>>
>>> Move calling the complete callback function to the caller from
>>> v4l2_async_test_notify and undo the work that was done either in async
>>> sub-device or async notifier registration.
>>>
>>> Reported-by: Russell King <rmk+kernel@armlinux.org.uk>
>>> Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
>>> ---
>>>  drivers/media/v4l2-core/v4l2-async.c | 78 +++++++++++++++++++++++++++---------
>>>  1 file changed, 60 insertions(+), 18 deletions(-)
>>>
>>> diff --git a/drivers/media/v4l2-core/v4l2-async.c b/drivers/media/v4l2-core/v4l2-async.c
>>> index ca281438a0ae..4924481451ca 100644
>>> --- a/drivers/media/v4l2-core/v4l2-async.c
>>> +++ b/drivers/media/v4l2-core/v4l2-async.c
>>> @@ -122,9 +122,6 @@ static int v4l2_async_test_notify(struct v4l2_async_notifier *notifier,
>>>  	/* Move from the global subdevice list to notifier's done */
>>>  	list_move(&sd->async_list, &notifier->done);
>>>  
>>> -	if (list_empty(&notifier->waiting) && notifier->complete)
>>> -		return notifier->complete(notifier);
>>> -
>>>  	return 0;
>>>  }
>>>  
>>> @@ -136,11 +133,27 @@ static void v4l2_async_cleanup(struct v4l2_subdev *sd)
>>>  	sd->asd = NULL;
>>>  }
>>>  
>>> +static void v4l2_async_notifier_unbind_all_subdevs(
>>> +	struct v4l2_async_notifier *notifier)
>>> +{
>>> +	struct v4l2_subdev *sd, *tmp;
>>> +
>>> +	list_for_each_entry_safe(sd, tmp, &notifier->done, async_list) {
>>> +		if (notifier->unbind)
>>> +			notifier->unbind(notifier, sd, sd->asd);
>>> +
>>> +		v4l2_async_cleanup(sd);
>>> +
>>> +		list_move(&sd->async_list, &subdev_list);
>>> +	}
>>> +}
>>> +
>>>  int v4l2_async_notifier_register(struct v4l2_device *v4l2_dev,
>>>  				 struct v4l2_async_notifier *notifier)
>>>  {
>>>  	struct v4l2_subdev *sd, *tmp;
>>>  	struct v4l2_async_subdev *asd;
>>> +	int ret;
>>>  	int i;
>>>  
>>>  	if (!v4l2_dev || !notifier->num_subdevs ||
>>> @@ -185,19 +198,30 @@ int v4l2_async_notifier_register(struct v4l2_device *v4l2_dev,
>>>  		}
>>>  	}
>>>  
>>> +	if (list_empty(&notifier->waiting) && notifier->complete) {
>>> +		ret = notifier->complete(notifier);
>>> +		if (ret)
>>> +			goto err_complete;
>>> +	}
>>> +
>>>  	/* Keep also completed notifiers on the list */
>>>  	list_add(&notifier->list, &notifier_list);
>>>  
>>>  	mutex_unlock(&list_lock);
>>>  
>>>  	return 0;
>>> +
>>> +err_complete:
>>> +	v4l2_async_notifier_unbind_all_subdevs(notifier);
>>> +
>>> +	mutex_unlock(&list_lock);
>>> +
>>> +	return ret;
>>>  }
>>>  EXPORT_SYMBOL(v4l2_async_notifier_register);
>>>  
>>>  void v4l2_async_notifier_unregister(struct v4l2_async_notifier *notifier)
>>>  {
>>> -	struct v4l2_subdev *sd, *tmp;
>>> -
>>>  	if (!notifier->v4l2_dev)
>>>  		return;
>>>  
>>> @@ -205,14 +229,7 @@ void v4l2_async_notifier_unregister(struct v4l2_async_notifier *notifier)
>>>  
>>>  	list_del(&notifier->list);
>>>  
>>> -	list_for_each_entry_safe(sd, tmp, &notifier->done, async_list) {
>>> -		if (notifier->unbind)
>>> -			notifier->unbind(notifier, sd, sd->asd);
>>> -
>>> -		v4l2_async_cleanup(sd);
>>> -
>>> -		list_move(&sd->async_list, &subdev_list);
>>> -	}
>>> +	v4l2_async_notifier_unbind_all_subdevs(notifier);
>>>  
>>>  	mutex_unlock(&list_lock);
>>>  
>>> @@ -223,6 +240,7 @@ EXPORT_SYMBOL(v4l2_async_notifier_unregister);
>>>  int v4l2_async_register_subdev(struct v4l2_subdev *sd)
>>>  {
>>>  	struct v4l2_async_notifier *notifier;
>>> +	int ret;
>>>  
>>>  	/*
>>>  	 * No reference taken. The reference is held by the device
>>> @@ -238,19 +256,43 @@ int v4l2_async_register_subdev(struct v4l2_subdev *sd)
>>>  
>>>  	list_for_each_entry(notifier, &notifier_list, list) {
>>>  		struct v4l2_async_subdev *asd = v4l2_async_belongs(notifier, sd);
>>> -		if (asd) {
>>> -			int ret = v4l2_async_test_notify(notifier, sd, asd);
>>> -			mutex_unlock(&list_lock);
>>> -			return ret;
>>> -		}
>>> +		int ret;
>>> +
>>> +		if (!asd)
>>> +			continue;
>>> +
>>> +		ret = v4l2_async_test_notify(notifier, sd, asd);
>>> +		if (ret)
>>> +			goto err_unlock;
>>> +
>>> +		if (!list_empty(&notifier->waiting) || !notifier->complete)
>>> +			goto out_unlock;
>>> +
>>> +		ret = notifier->complete(notifier);
>>> +		if (ret)
>>> +			goto err_cleanup;
>>> +
>>> +		goto out_unlock;
>>>  	}
>>>  
>>>  	/* None matched, wait for hot-plugging */
>>>  	list_add(&sd->async_list, &subdev_list);
>>>  
>>> +out_unlock:
>>>  	mutex_unlock(&list_lock);
>>>  
>>>  	return 0;
>>> +
>>> +err_cleanup:
>>> +	if (notifier->unbind)
>>> +		notifier->unbind(notifier, sd, sd->asd);
>>> +
>>> +	v4l2_async_cleanup(sd);
>>
>> I'm trying to understand this. Who will unbind all subdevs in this case?
> 
> The driver that registered them is responsible for that, as usual.
> 
>>
>> And in the general case: if complete returns an error, the bridge driver
>> should be remove()d. Who will do that? Does that work at all?
> 
> The bridge driver can't do that alone, the bridge driver would need to be
> unbound explicitly by the user.
> 
> This approach has the benefit that it's symmetric: on error we only tear
> down the part that was added, no more. Doing otherwise would likely make
> the error handling hard to understand and test properly. For instance, if a
> driver's probe function calling v4l2_async_register_subdev() or
> v4l2_async_notifier_register() fails, leading the driver binding to fail.
> If the error is temporary for whatever reason, just retrying the operation
> will help.
> 

So to be clear: if complete() returns an error, then you basically end up with
a 'zombie' device: it's been successfully probed, but because complete() failed
it will just sit there until the user unbinds it (typically via rmmod).

For the record: this will only happen if the subdev is loaded after the main
driver. If the subdev is loaded before the main driver, then when the main driver
calls v4l2_async_notifier_register() from the probe() function it will return an
error and the probe will fail with an error.

Do I understand this correctly?

Regards,

	Hans

Re: [PATCH v15 04/32] v4l: async: Fix notifier complete callback error handling

[Sakari Ailus]

Hi Hans,

On Tue, Oct 10, 2017 at 03:18:13PM +0200, Hans Verkuil wrote:
> On 10/10/2017 02:57 PM, Sakari Ailus wrote:
> > Hi Hans,
> > 
> > On Mon, Oct 09, 2017 at 01:45:25PM +0200, Hans Verkuil wrote:
> >> On 04/10/17 23:50, Sakari Ailus wrote:
> >>> The notifier complete callback may return an error. This error code was
> >>> simply returned to the caller but never handled properly.
> >>>
> >>> Move calling the complete callback function to the caller from
> >>> v4l2_async_test_notify and undo the work that was done either in async
> >>> sub-device or async notifier registration.
> >>>
> >>> Reported-by: Russell King <rmk+kernel@armlinux.org.uk>
> >>> Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
> >>> ---
> >>>  drivers/media/v4l2-core/v4l2-async.c | 78 +++++++++++++++++++++++++++---------
> >>>  1 file changed, 60 insertions(+), 18 deletions(-)
> >>>
> >>> diff --git a/drivers/media/v4l2-core/v4l2-async.c b/drivers/media/v4l2-core/v4l2-async.c
> >>> index ca281438a0ae..4924481451ca 100644
> >>> --- a/drivers/media/v4l2-core/v4l2-async.c
> >>> +++ b/drivers/media/v4l2-core/v4l2-async.c
> >>> @@ -122,9 +122,6 @@ static int v4l2_async_test_notify(struct v4l2_async_notifier *notifier,
> >>>  	/* Move from the global subdevice list to notifier's done */
> >>>  	list_move(&sd->async_list, &notifier->done);
> >>>  
> >>> -	if (list_empty(&notifier->waiting) && notifier->complete)
> >>> -		return notifier->complete(notifier);
> >>> -
> >>>  	return 0;
> >>>  }
> >>>  
> >>> @@ -136,11 +133,27 @@ static void v4l2_async_cleanup(struct v4l2_subdev *sd)
> >>>  	sd->asd = NULL;
> >>>  }
> >>>  
> >>> +static void v4l2_async_notifier_unbind_all_subdevs(
> >>> +	struct v4l2_async_notifier *notifier)
> >>> +{
> >>> +	struct v4l2_subdev *sd, *tmp;
> >>> +
> >>> +	list_for_each_entry_safe(sd, tmp, &notifier->done, async_list) {
> >>> +		if (notifier->unbind)
> >>> +			notifier->unbind(notifier, sd, sd->asd);
> >>> +
> >>> +		v4l2_async_cleanup(sd);
> >>> +
> >>> +		list_move(&sd->async_list, &subdev_list);
> >>> +	}
> >>> +}
> >>> +
> >>>  int v4l2_async_notifier_register(struct v4l2_device *v4l2_dev,
> >>>  				 struct v4l2_async_notifier *notifier)
> >>>  {
> >>>  	struct v4l2_subdev *sd, *tmp;
> >>>  	struct v4l2_async_subdev *asd;
> >>> +	int ret;
> >>>  	int i;
> >>>  
> >>>  	if (!v4l2_dev || !notifier->num_subdevs ||
> >>> @@ -185,19 +198,30 @@ int v4l2_async_notifier_register(struct v4l2_device *v4l2_dev,
> >>>  		}
> >>>  	}
> >>>  
> >>> +	if (list_empty(&notifier->waiting) && notifier->complete) {
> >>> +		ret = notifier->complete(notifier);
> >>> +		if (ret)
> >>> +			goto err_complete;
> >>> +	}
> >>> +
> >>>  	/* Keep also completed notifiers on the list */
> >>>  	list_add(&notifier->list, &notifier_list);
> >>>  
> >>>  	mutex_unlock(&list_lock);
> >>>  
> >>>  	return 0;
> >>> +
> >>> +err_complete:
> >>> +	v4l2_async_notifier_unbind_all_subdevs(notifier);
> >>> +
> >>> +	mutex_unlock(&list_lock);
> >>> +
> >>> +	return ret;
> >>>  }
> >>>  EXPORT_SYMBOL(v4l2_async_notifier_register);
> >>>  
> >>>  void v4l2_async_notifier_unregister(struct v4l2_async_notifier *notifier)
> >>>  {
> >>> -	struct v4l2_subdev *sd, *tmp;
> >>> -
> >>>  	if (!notifier->v4l2_dev)
> >>>  		return;
> >>>  
> >>> @@ -205,14 +229,7 @@ void v4l2_async_notifier_unregister(struct v4l2_async_notifier *notifier)
> >>>  
> >>>  	list_del(&notifier->list);
> >>>  
> >>> -	list_for_each_entry_safe(sd, tmp, &notifier->done, async_list) {
> >>> -		if (notifier->unbind)
> >>> -			notifier->unbind(notifier, sd, sd->asd);
> >>> -
> >>> -		v4l2_async_cleanup(sd);
> >>> -
> >>> -		list_move(&sd->async_list, &subdev_list);
> >>> -	}
> >>> +	v4l2_async_notifier_unbind_all_subdevs(notifier);
> >>>  
> >>>  	mutex_unlock(&list_lock);
> >>>  
> >>> @@ -223,6 +240,7 @@ EXPORT_SYMBOL(v4l2_async_notifier_unregister);
> >>>  int v4l2_async_register_subdev(struct v4l2_subdev *sd)
> >>>  {
> >>>  	struct v4l2_async_notifier *notifier;
> >>> +	int ret;
> >>>  
> >>>  	/*
> >>>  	 * No reference taken. The reference is held by the device
> >>> @@ -238,19 +256,43 @@ int v4l2_async_register_subdev(struct v4l2_subdev *sd)
> >>>  
> >>>  	list_for_each_entry(notifier, &notifier_list, list) {
> >>>  		struct v4l2_async_subdev *asd = v4l2_async_belongs(notifier, sd);
> >>> -		if (asd) {
> >>> -			int ret = v4l2_async_test_notify(notifier, sd, asd);
> >>> -			mutex_unlock(&list_lock);
> >>> -			return ret;
> >>> -		}
> >>> +		int ret;
> >>> +
> >>> +		if (!asd)
> >>> +			continue;
> >>> +
> >>> +		ret = v4l2_async_test_notify(notifier, sd, asd);
> >>> +		if (ret)
> >>> +			goto err_unlock;
> >>> +
> >>> +		if (!list_empty(&notifier->waiting) || !notifier->complete)
> >>> +			goto out_unlock;
> >>> +
> >>> +		ret = notifier->complete(notifier);
> >>> +		if (ret)
> >>> +			goto err_cleanup;
> >>> +
> >>> +		goto out_unlock;
> >>>  	}
> >>>  
> >>>  	/* None matched, wait for hot-plugging */
> >>>  	list_add(&sd->async_list, &subdev_list);
> >>>  
> >>> +out_unlock:
> >>>  	mutex_unlock(&list_lock);
> >>>  
> >>>  	return 0;
> >>> +
> >>> +err_cleanup:
> >>> +	if (notifier->unbind)
> >>> +		notifier->unbind(notifier, sd, sd->asd);
> >>> +
> >>> +	v4l2_async_cleanup(sd);
> >>
> >> I'm trying to understand this. Who will unbind all subdevs in this case?
> > 
> > The driver that registered them is responsible for that, as usual.
> > 
> >>
> >> And in the general case: if complete returns an error, the bridge driver
> >> should be remove()d. Who will do that? Does that work at all?
> > 
> > The bridge driver can't do that alone, the bridge driver would need to be
> > unbound explicitly by the user.
> > 
> > This approach has the benefit that it's symmetric: on error we only tear
> > down the part that was added, no more. Doing otherwise would likely make
> > the error handling hard to understand and test properly. For instance, if a
> > driver's probe function calling v4l2_async_register_subdev() or
> > v4l2_async_notifier_register() fails, leading the driver binding to fail.
> > If the error is temporary for whatever reason, just retrying the operation
> > will help.
> > 
> 
> So to be clear: if complete() returns an error, then you basically end up with
> a 'zombie' device: it's been successfully probed, but because complete() failed
> it will just sit there until the user unbinds it (typically via rmmod).

Either that, or the complete callback is called again by re-probing the
sub-device driver (which failed as v4l2_async_register_subdev() failed).

> 
> For the record: this will only happen if the subdev is loaded after the main
> driver. If the subdev is loaded before the main driver, then when the main driver
> calls v4l2_async_notifier_register() from the probe() function it will return an
> error and the probe will fail with an error.

Correct.

In the long run it'd be good to get rid of the complete callback entirely
or make its return value void. I think that's still a separate matter
though.

Speaking of complete callbacks --- I don't think we have a use case for
calling them from the sub-device notifiers. I'll disable them in v16 for
that reason: we don't want to embrace their use, especially without a valid
reason.

-- 
Regards,

Sakari Ailus
sakari.ailus@linux.intel.com

Re: [PATCH v15 20/32] dt: bindings: Add a binding for flash LED devices associated to a sensor

[Rob Herring]

On Thu, Oct 05, 2017 at 12:50:39AM +0300, Sakari Ailus wrote:
> Camera flash drivers (and LEDs) are separate from the sensor devices in
> DT. In order to make an association between the two, provide the
> association information to the software.
> 
> Signed-off-by: Sakari Ailus <sakari.ailus-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
> Cc: Rob Herring <robh-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
> Cc: devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
> Acked-by: Hans Verkuil <hans.verkuil-FYB4Gu1CFyUAvxtiuMwx3w@public.gmane.org>
> Acked-by: Pavel Machek <pavel-+ZI9xUNit7I@public.gmane.org>
> ---
>  Documentation/devicetree/bindings/media/video-interfaces.txt | 8 ++++++++
>  1 file changed, 8 insertions(+)

Acked-by: Rob Herring <robh-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>

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Re: [PATCH v15 20/32] dt: bindings: Add a binding for flash LED devices associated to a sensor

[Rob Herring]

On Thu, Oct 05, 2017 at 12:50:39AM +0300, Sakari Ailus wrote:
> Camera flash drivers (and LEDs) are separate from the sensor devices in
> DT. In order to make an association between the two, provide the
> association information to the software.
> 
> Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
> Cc: Rob Herring <robh@kernel.org>
> Cc: devicetree@vger.kernel.org
> Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
> Acked-by: Pavel Machek <pavel@ucw.cz>
> ---
>  Documentation/devicetree/bindings/media/video-interfaces.txt | 8 ++++++++
>  1 file changed, 8 insertions(+)

Acked-by: Rob Herring <robh@kernel.org>

[PATCH v15.1 24/32] v4l: fwnode: Add a helper function to obtain device / integer references

[Sakari Ailus]

v4l2_fwnode_reference_parse_int_prop() will find an fwnode such that under
the device's own fwnode, it will follow child fwnodes with the given
property-value pair and return the resulting fwnode.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
---
since v15:

- Use a graph example instead of a LED one; this way nprops will be 2.

 drivers/media/v4l2-core/v4l2-fwnode.c | 252 ++++++++++++++++++++++++++++++++++
 1 file changed, 252 insertions(+)

diff --git a/drivers/media/v4l2-core/v4l2-fwnode.c b/drivers/media/v4l2-core/v4l2-fwnode.c
index edd2e8d983a1..989a6f8a09fa 100644
--- a/drivers/media/v4l2-core/v4l2-fwnode.c
+++ b/drivers/media/v4l2-core/v4l2-fwnode.c
@@ -578,6 +578,258 @@ static int v4l2_fwnode_reference_parse(
 	return ret;
 }
 
+/*
+ * v4l2_fwnode_reference_get_int_prop - parse a reference with integer
+ *					arguments
+ * @fwnode: fwnode to read @prop from
+ * @notifier: notifier for @dev
+ * @prop: the name of the property
+ * @index: the index of the reference to get
+ * @props: the array of integer property names
+ * @nprops: the number of integer property names in @nprops
+ *
+ * First find an fwnode referred to by the reference at @index in @prop.
+ *
+ * Then under that fwnode, @nprops times, for each property in @props,
+ * iteratively follow child nodes starting from fwnode such that they have the
+ * property in @props array at the index of the child node distance from the
+ * root node and the value of that property matching with the integer argument
+ * of the reference, at the same index.
+ *
+ * The child fwnode reched at the end of the iteration is then returned to the
+ * caller.
+ *
+ * An example with a graph, as defined in Documentation/acpi/dsd/graph.txt:
+ *
+ *	Scope (\_SB.PCI0.I2C2)
+ *	{
+ *		Device (CAM0)
+ *		{
+ *			Name (_DSD, Package () {
+ *				ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
+ *				Package () {
+ *					Package () {
+ *						"compatible",
+ *						Package () { "nokia,smia" }
+ *					},
+ *				},
+ *				ToUUID("dbb8e3e6-5886-4ba6-8795-1319f52a966b"),
+ *				Package () {
+ *					Package () { "port0", "PRT0" },
+ *				}
+ *			})
+ *			Name (PRT0, Package() {
+ *				ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
+ *				Package () {
+ *					Package () { "port", 0 },
+ *				},
+ *				ToUUID("dbb8e3e6-5886-4ba6-8795-1319f52a966b"),
+ *				Package () {
+ *					Package () { "endpoint0", "EP00" },
+ *				}
+ *			})
+ *			Name (EP00, Package() {
+ *				ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
+ *				Package () {
+ *					Package () { "endpoint", 0 },
+ *					Package () {
+ *						"remote-endpoint",
+ *						Package() {
+ *							\_SB.PCI0.ISP, 4, 0
+ *						}
+ *					},
+ *				}
+ *			})
+ *		}
+ *	}
+ *
+ *	Scope (\_SB.PCI0)
+ *	{
+ *		Device (ISP)
+ *		{
+ *			Name (_DSD, Package () {
+ *				ToUUID("dbb8e3e6-5886-4ba6-8795-1319f52a966b"),
+ *				Package () {
+ *					Package () { "port4", "PRT4" },
+ *				}
+ *			})
+ *
+ *			Name (PRT4, Package() {
+ *				ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
+ *				Package () {
+ *					Package () { "port", 4 },
+ *				},
+ *				ToUUID("dbb8e3e6-5886-4ba6-8795-1319f52a966b"),
+ *				Package () {
+ *					Package () { "endpoint0", "EP40" },
+ *				}
+ *			})
+ *
+ *			Name (EP40, Package() {
+ *				ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
+ *				Package () {
+ *					Package () { "endpoint", 0 },
+ *					Package () {
+ *						"remote-endpoint",
+ *						Package () {
+ *							\_SB.PCI0.I2C2.CAM0,
+ *							0, 0
+ *						}
+ *					},
+ *				}
+ *			})
+ *		}
+ *	}
+ *
+ * From the EP40 node under ISP device, you could parse the graph remote
+ * endpoint using v4l2_fwnode_reference_get_int_prop with these arguments:
+ *
+ *  @fwnode: fwnode referring to EP40 under ISP.
+ *  @prop: "remote-endpoint"
+ *  @index: 0
+ *  @props: "port", "endpoint"
+ *  @nprops: 2
+ *
+ * And you'd get back fwnode referring to EP00 under CAM0.
+ *
+ * The same works the other way around: if you use EP00 under CAM0 as the
+ * fwnode, you'll get fwnode referring to EP40 under ISP.
+ *
+ * Return: 0 on success
+ *	   -ENOENT if no entries (or the property itself) were found
+ *	   -EINVAL if property parsing otherwise failed
+ *	   -ENOMEM if memory allocation failed
+ */
+static struct fwnode_handle *v4l2_fwnode_reference_get_int_prop(
+	struct fwnode_handle *fwnode, const char *prop, unsigned int index,
+	const char **props, unsigned int nprops)
+{
+	struct fwnode_reference_args fwnode_args;
+	unsigned int *args = fwnode_args.args;
+	struct fwnode_handle *child;
+	int ret;
+
+	/*
+	 * Obtain remote fwnode as well as the integer arguments.
+	 *
+	 * Note that right now both -ENODATA and -ENOENT may signal
+	 * out-of-bounds access. Return -ENOENT in that case.
+	 */
+	ret = fwnode_property_get_reference_args(fwnode, prop, NULL, nprops,
+						 index, &fwnode_args);
+	if (ret)
+		return ERR_PTR(ret == -ENODATA ? -ENOENT : ret);
+
+	/*
+	 * Find a node in the tree under the referred fwnode corresponding to
+	 * the integer arguments.
+	 */
+	fwnode = fwnode_args.fwnode;
+	while (nprops--) {
+		u32 val;
+
+		/* Loop over all child nodes under fwnode. */
+		fwnode_for_each_child_node(fwnode, child) {
+			if (fwnode_property_read_u32(child, *props, &val))
+				continue;
+
+			/* Found property, see if its value matches. */
+			if (val == *args)
+				break;
+		}
+
+		fwnode_handle_put(fwnode);
+
+		/* No property found; return an error here. */
+		if (!child) {
+			fwnode = ERR_PTR(-ENOENT);
+			break;
+		}
+
+		props++;
+		args++;
+		fwnode = child;
+	}
+
+	return fwnode;
+}
+
+/*
+ * v4l2_fwnode_reference_parse_int_props - parse references for async sub-devices
+ * @dev: struct device pointer
+ * @notifier: notifier for @dev
+ * @prop: the name of the property
+ * @props: the array of integer property names
+ * @nprops: the number of integer properties
+ *
+ * Use v4l2_fwnode_reference_get_int_prop to find fwnodes through reference in
+ * property @prop with integer arguments with child nodes matching in properties
+ * @props. Then, set up V4L2 async sub-devices for those fwnodes in the notifier
+ * accordingly.
+ *
+ * While it is technically possible to use this function on DT, it is only
+ * meaningful on ACPI. On Device tree you can refer to any node in the tree but
+ * on ACPI the references are limited to devices.
+ *
+ * Return: 0 on success
+ *	   -ENOENT if no entries (or the property itself) were found
+ *	   -EINVAL if property parsing otherwisefailed
+ *	   -ENOMEM if memory allocation failed
+ */
+static int v4l2_fwnode_reference_parse_int_props(
+	struct device *dev, struct v4l2_async_notifier *notifier,
+	const char *prop, const char **props, unsigned int nprops)
+{
+	struct fwnode_handle *fwnode;
+	unsigned int index;
+	int ret;
+
+	for (index = 0; !IS_ERR((fwnode = v4l2_fwnode_reference_get_int_prop(
+					 dev_fwnode(dev), prop, index, props,
+					 nprops))); index++)
+		fwnode_handle_put(fwnode);
+
+	/*
+	 * Note that right now both -ENODATA and -ENOENT may signal
+	 * out-of-bounds access. Return the error in cases other than that.
+	 */
+	if (PTR_ERR(fwnode) != -ENOENT && PTR_ERR(fwnode) != -ENODATA)
+		return PTR_ERR(fwnode);
+
+	ret = v4l2_async_notifier_realloc(notifier,
+					  notifier->num_subdevs + index);
+	if (ret)
+		return -ENOMEM;
+
+	for (index = 0; !IS_ERR((fwnode = v4l2_fwnode_reference_get_int_prop(
+					 dev_fwnode(dev), prop, index, props,
+					 nprops))); index++) {
+		struct v4l2_async_subdev *asd;
+
+		if (WARN_ON(notifier->num_subdevs >= notifier->max_subdevs)) {
+			ret = -EINVAL;
+			goto error;
+		}
+
+		asd = kzalloc(sizeof(struct v4l2_async_subdev), GFP_KERNEL);
+		if (!asd) {
+			ret = -ENOMEM;
+			goto error;
+		}
+
+		notifier->subdevs[notifier->num_subdevs] = asd;
+		asd->match.fwnode.fwnode = fwnode;
+		asd->match_type = V4L2_ASYNC_MATCH_FWNODE;
+		notifier->num_subdevs++;
+	}
+
+	return PTR_ERR(fwnode) == -ENOENT ? 0 : PTR_ERR(fwnode);
+
+error:
+	fwnode_handle_put(fwnode);
+	return ret;
+}
+
 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Sakari Ailus <sakari.ailus@linux.intel.com>");
 MODULE_AUTHOR("Sylwester Nawrocki <s.nawrocki@samsung.com>");
-- 
2.11.0

Re: [PATCH v15.1 24/32] v4l: fwnode: Add a helper function to obtain device / integer references

[Sakari Ailus]

On Wed, Oct 18, 2017 at 04:56:56PM +0300, Sakari Ailus wrote:
> v4l2_fwnode_reference_parse_int_prop() will find an fwnode such that under
> the device's own fwnode, it will follow child fwnodes with the given
> property-value pair and return the resulting fwnode.
> 
> Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
> ---
> since v15:
> 
> - Use a graph example instead of a LED one; this way nprops will be 2.
> 
>  drivers/media/v4l2-core/v4l2-fwnode.c | 252 ++++++++++++++++++++++++++++++++++
>  1 file changed, 252 insertions(+)
> 
> diff --git a/drivers/media/v4l2-core/v4l2-fwnode.c b/drivers/media/v4l2-core/v4l2-fwnode.c
> index edd2e8d983a1..989a6f8a09fa 100644
> --- a/drivers/media/v4l2-core/v4l2-fwnode.c
> +++ b/drivers/media/v4l2-core/v4l2-fwnode.c
> @@ -578,6 +578,258 @@ static int v4l2_fwnode_reference_parse(
>  	return ret;
>  }
>  
> +/*
> + * v4l2_fwnode_reference_get_int_prop - parse a reference with integer
> + *					arguments
> + * @fwnode: fwnode to read @prop from
> + * @notifier: notifier for @dev
> + * @prop: the name of the property
> + * @index: the index of the reference to get
> + * @props: the array of integer property names
> + * @nprops: the number of integer property names in @nprops
> + *
> + * First find an fwnode referred to by the reference at @index in @prop.
> + *
> + * Then under that fwnode, @nprops times, for each property in @props,
> + * iteratively follow child nodes starting from fwnode such that they have the
> + * property in @props array at the index of the child node distance from the
> + * root node and the value of that property matching with the integer argument
> + * of the reference, at the same index.
> + *
> + * The child fwnode reched at the end of the iteration is then returned to the
> + * caller.

An alternative to these three paragraphs could be:

First obtain an fwnode, with integer arguments, referred to by the reference
at @index in @prop. These shall be referred as "remote fwnode" and "remote
fwnode arguments".

Under the remote fwnode, perform the following steps iteratively @nprops
times. Let the number of iteration be "i", starting from 0.

1. Designate the remote fwnode as the "current fwnode".

2. Begin iterating child fwnodes under the current fwnode.

3. Find next child fwnode under the current fwnode. If no node is found,
   return NULL.

4. From the child fwnode, read 32-bit unsigned integer property named as
   the i'th element in @props array.

5. Compare the value of that integer property with the i'th element in the
   remote fwnode argument array. If the values do not match, go to (3).

6. Increment i by one. If i matches with @nprops, return the child fwnode.

7. Designate the child fwnode as the current fwnode and continue from (2).

> + *
> + * An example with a graph, as defined in Documentation/acpi/dsd/graph.txt:
> + *
> + *	Scope (\_SB.PCI0.I2C2)
> + *	{
> + *		Device (CAM0)
> + *		{
> + *			Name (_DSD, Package () {
> + *				ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
> + *				Package () {
> + *					Package () {
> + *						"compatible",
> + *						Package () { "nokia,smia" }
> + *					},
> + *				},
> + *				ToUUID("dbb8e3e6-5886-4ba6-8795-1319f52a966b"),
> + *				Package () {
> + *					Package () { "port0", "PRT0" },
> + *				}
> + *			})
> + *			Name (PRT0, Package() {
> + *				ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
> + *				Package () {
> + *					Package () { "port", 0 },
> + *				},
> + *				ToUUID("dbb8e3e6-5886-4ba6-8795-1319f52a966b"),
> + *				Package () {
> + *					Package () { "endpoint0", "EP00" },
> + *				}
> + *			})
> + *			Name (EP00, Package() {
> + *				ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
> + *				Package () {
> + *					Package () { "endpoint", 0 },
> + *					Package () {
> + *						"remote-endpoint",
> + *						Package() {
> + *							\_SB.PCI0.ISP, 4, 0
> + *						}
> + *					},
> + *				}
> + *			})
> + *		}
> + *	}
> + *
> + *	Scope (\_SB.PCI0)
> + *	{
> + *		Device (ISP)
> + *		{
> + *			Name (_DSD, Package () {
> + *				ToUUID("dbb8e3e6-5886-4ba6-8795-1319f52a966b"),
> + *				Package () {
> + *					Package () { "port4", "PRT4" },
> + *				}
> + *			})
> + *
> + *			Name (PRT4, Package() {
> + *				ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
> + *				Package () {
> + *					Package () { "port", 4 },
> + *				},
> + *				ToUUID("dbb8e3e6-5886-4ba6-8795-1319f52a966b"),
> + *				Package () {
> + *					Package () { "endpoint0", "EP40" },
> + *				}
> + *			})
> + *
> + *			Name (EP40, Package() {
> + *				ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
> + *				Package () {
> + *					Package () { "endpoint", 0 },
> + *					Package () {
> + *						"remote-endpoint",
> + *						Package () {
> + *							\_SB.PCI0.I2C2.CAM0,
> + *							0, 0
> + *						}
> + *					},
> + *				}
> + *			})
> + *		}
> + *	}
> + *
> + * From the EP40 node under ISP device, you could parse the graph remote
> + * endpoint using v4l2_fwnode_reference_get_int_prop with these arguments:
> + *
> + *  @fwnode: fwnode referring to EP40 under ISP.
> + *  @prop: "remote-endpoint"
> + *  @index: 0
> + *  @props: "port", "endpoint"
> + *  @nprops: 2
> + *
> + * And you'd get back fwnode referring to EP00 under CAM0.
> + *
> + * The same works the other way around: if you use EP00 under CAM0 as the
> + * fwnode, you'll get fwnode referring to EP40 under ISP.
> + *
> + * Return: 0 on success
> + *	   -ENOENT if no entries (or the property itself) were found
> + *	   -EINVAL if property parsing otherwise failed
> + *	   -ENOMEM if memory allocation failed
> + */
> +static struct fwnode_handle *v4l2_fwnode_reference_get_int_prop(
> +	struct fwnode_handle *fwnode, const char *prop, unsigned int index,
> +	const char **props, unsigned int nprops)
> +{
> +	struct fwnode_reference_args fwnode_args;
> +	unsigned int *args = fwnode_args.args;
> +	struct fwnode_handle *child;
> +	int ret;
> +
> +	/*
> +	 * Obtain remote fwnode as well as the integer arguments.
> +	 *
> +	 * Note that right now both -ENODATA and -ENOENT may signal
> +	 * out-of-bounds access. Return -ENOENT in that case.
> +	 */
> +	ret = fwnode_property_get_reference_args(fwnode, prop, NULL, nprops,
> +						 index, &fwnode_args);
> +	if (ret)
> +		return ERR_PTR(ret == -ENODATA ? -ENOENT : ret);
> +
> +	/*
> +	 * Find a node in the tree under the referred fwnode corresponding to
> +	 * the integer arguments.
> +	 */
> +	fwnode = fwnode_args.fwnode;
> +	while (nprops--) {
> +		u32 val;
> +
> +		/* Loop over all child nodes under fwnode. */
> +		fwnode_for_each_child_node(fwnode, child) {
> +			if (fwnode_property_read_u32(child, *props, &val))
> +				continue;
> +
> +			/* Found property, see if its value matches. */
> +			if (val == *args)
> +				break;
> +		}
> +
> +		fwnode_handle_put(fwnode);
> +
> +		/* No property found; return an error here. */
> +		if (!child) {
> +			fwnode = ERR_PTR(-ENOENT);
> +			break;
> +		}
> +
> +		props++;
> +		args++;
> +		fwnode = child;
> +	}
> +
> +	return fwnode;
> +}
> +
> +/*
> + * v4l2_fwnode_reference_parse_int_props - parse references for async sub-devices
> + * @dev: struct device pointer
> + * @notifier: notifier for @dev
> + * @prop: the name of the property
> + * @props: the array of integer property names
> + * @nprops: the number of integer properties
> + *
> + * Use v4l2_fwnode_reference_get_int_prop to find fwnodes through reference in
> + * property @prop with integer arguments with child nodes matching in properties
> + * @props. Then, set up V4L2 async sub-devices for those fwnodes in the notifier
> + * accordingly.
> + *
> + * While it is technically possible to use this function on DT, it is only
> + * meaningful on ACPI. On Device tree you can refer to any node in the tree but
> + * on ACPI the references are limited to devices.
> + *
> + * Return: 0 on success
> + *	   -ENOENT if no entries (or the property itself) were found
> + *	   -EINVAL if property parsing otherwisefailed
> + *	   -ENOMEM if memory allocation failed
> + */
> +static int v4l2_fwnode_reference_parse_int_props(
> +	struct device *dev, struct v4l2_async_notifier *notifier,
> +	const char *prop, const char **props, unsigned int nprops)
> +{
> +	struct fwnode_handle *fwnode;
> +	unsigned int index;
> +	int ret;
> +
> +	for (index = 0; !IS_ERR((fwnode = v4l2_fwnode_reference_get_int_prop(
> +					 dev_fwnode(dev), prop, index, props,
> +					 nprops))); index++)
> +		fwnode_handle_put(fwnode);
> +
> +	/*
> +	 * Note that right now both -ENODATA and -ENOENT may signal
> +	 * out-of-bounds access. Return the error in cases other than that.
> +	 */
> +	if (PTR_ERR(fwnode) != -ENOENT && PTR_ERR(fwnode) != -ENODATA)
> +		return PTR_ERR(fwnode);
> +
> +	ret = v4l2_async_notifier_realloc(notifier,
> +					  notifier->num_subdevs + index);
> +	if (ret)
> +		return -ENOMEM;
> +
> +	for (index = 0; !IS_ERR((fwnode = v4l2_fwnode_reference_get_int_prop(
> +					 dev_fwnode(dev), prop, index, props,
> +					 nprops))); index++) {
> +		struct v4l2_async_subdev *asd;
> +
> +		if (WARN_ON(notifier->num_subdevs >= notifier->max_subdevs)) {
> +			ret = -EINVAL;
> +			goto error;
> +		}
> +
> +		asd = kzalloc(sizeof(struct v4l2_async_subdev), GFP_KERNEL);
> +		if (!asd) {
> +			ret = -ENOMEM;
> +			goto error;
> +		}
> +
> +		notifier->subdevs[notifier->num_subdevs] = asd;
> +		asd->match.fwnode.fwnode = fwnode;
> +		asd->match_type = V4L2_ASYNC_MATCH_FWNODE;
> +		notifier->num_subdevs++;
> +	}
> +
> +	return PTR_ERR(fwnode) == -ENOENT ? 0 : PTR_ERR(fwnode);
> +
> +error:
> +	fwnode_handle_put(fwnode);
> +	return ret;
> +}
> +
>  MODULE_LICENSE("GPL");
>  MODULE_AUTHOR("Sakari Ailus <sakari.ailus@linux.intel.com>");
>  MODULE_AUTHOR("Sylwester Nawrocki <s.nawrocki@samsung.com>");
> -- 
> 2.11.0
> 

-- 
Sakari Ailus
e-mail: sakari.ailus@iki.fi

Re: [PATCH v15.1 24/32] v4l: fwnode: Add a helper function to obtain device / integer references

[Hans Verkuil]

On 10/18/2017 05:32 PM, Sakari Ailus wrote:
> On Wed, Oct 18, 2017 at 04:56:56PM +0300, Sakari Ailus wrote:
>> v4l2_fwnode_reference_parse_int_prop() will find an fwnode such that under
>> the device's own fwnode, it will follow child fwnodes with the given
>> property-value pair and return the resulting fwnode.
>>
>> Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
>> ---
>> since v15:
>>
>> - Use a graph example instead of a LED one; this way nprops will be 2.
>>
>>  drivers/media/v4l2-core/v4l2-fwnode.c | 252 ++++++++++++++++++++++++++++++++++
>>  1 file changed, 252 insertions(+)
>>
>> diff --git a/drivers/media/v4l2-core/v4l2-fwnode.c b/drivers/media/v4l2-core/v4l2-fwnode.c
>> index edd2e8d983a1..989a6f8a09fa 100644
>> --- a/drivers/media/v4l2-core/v4l2-fwnode.c
>> +++ b/drivers/media/v4l2-core/v4l2-fwnode.c
>> @@ -578,6 +578,258 @@ static int v4l2_fwnode_reference_parse(
>>  	return ret;
>>  }
>>  
>> +/*
>> + * v4l2_fwnode_reference_get_int_prop - parse a reference with integer
>> + *					arguments
>> + * @fwnode: fwnode to read @prop from
>> + * @notifier: notifier for @dev
>> + * @prop: the name of the property
>> + * @index: the index of the reference to get
>> + * @props: the array of integer property names
>> + * @nprops: the number of integer property names in @nprops
>> + *
>> + * First find an fwnode referred to by the reference at @index in @prop.
>> + *
>> + * Then under that fwnode, @nprops times, for each property in @props,
>> + * iteratively follow child nodes starting from fwnode such that they have the
>> + * property in @props array at the index of the child node distance from the
>> + * root node and the value of that property matching with the integer argument
>> + * of the reference, at the same index.
>> + *
>> + * The child fwnode reched at the end of the iteration is then returned to the
>> + * caller.
> 
> An alternative to these three paragraphs could be:
> 
> First obtain an fwnode, with integer arguments, referred to by the reference
> at @index in @prop. These shall be referred as "remote fwnode" and "remote
> fwnode arguments".
> 
> Under the remote fwnode, perform the following steps iteratively @nprops
> times. Let the number of iteration be "i", starting from 0.
> 
> 1. Designate the remote fwnode as the "current fwnode".
> 
> 2. Begin iterating child fwnodes under the current fwnode.
> 
> 3. Find next child fwnode under the current fwnode. If no node is found,
>    return NULL.
> 
> 4. From the child fwnode, read 32-bit unsigned integer property named as
>    the i'th element in @props array.
> 
> 5. Compare the value of that integer property with the i'th element in the
>    remote fwnode argument array. If the values do not match, go to (3).
> 
> 6. Increment i by one. If i matches with @nprops, return the child fwnode.
> 
> 7. Designate the child fwnode as the current fwnode and continue from (2).

This is definitely a better text.

However, this describes the mechanics of the function, not what its purpose
actually is.

The core reason for this is that you cannot refer to just any node in ACPI.
So to refer to an endpoint (easy in DT) you need to refer to a device, then
provide a list of (property name, property value) tuples where each tuple
uniquely identifies a child node. The first tuple identifies a child directly
underneath the device fwnode, the next tuple identifies a child node underneath
the fwnode identified by the previous tuple, etc. until you reached the fwnode
you need.

Does this make sense?

> 
>> + *
>> + * An example with a graph, as defined in Documentation/acpi/dsd/graph.txt:
>> + *
>> + *	Scope (\_SB.PCI0.I2C2)
>> + *	{
>> + *		Device (CAM0)
>> + *		{
>> + *			Name (_DSD, Package () {
>> + *				ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
>> + *				Package () {
>> + *					Package () {
>> + *						"compatible",
>> + *						Package () { "nokia,smia" }
>> + *					},
>> + *				},
>> + *				ToUUID("dbb8e3e6-5886-4ba6-8795-1319f52a966b"),
>> + *				Package () {
>> + *					Package () { "port0", "PRT0" },
>> + *				}
>> + *			})
>> + *			Name (PRT0, Package() {
>> + *				ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
>> + *				Package () {
>> + *					Package () { "port", 0 },
>> + *				},
>> + *				ToUUID("dbb8e3e6-5886-4ba6-8795-1319f52a966b"),
>> + *				Package () {
>> + *					Package () { "endpoint0", "EP00" },
>> + *				}
>> + *			})
>> + *			Name (EP00, Package() {
>> + *				ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
>> + *				Package () {
>> + *					Package () { "endpoint", 0 },
>> + *					Package () {
>> + *						"remote-endpoint",
>> + *						Package() {
>> + *							\_SB.PCI0.ISP, 4, 0
>> + *						}
>> + *					},
>> + *				}
>> + *			})
>> + *		}
>> + *	}
>> + *
>> + *	Scope (\_SB.PCI0)
>> + *	{
>> + *		Device (ISP)
>> + *		{
>> + *			Name (_DSD, Package () {
>> + *				ToUUID("dbb8e3e6-5886-4ba6-8795-1319f52a966b"),
>> + *				Package () {
>> + *					Package () { "port4", "PRT4" },
>> + *				}
>> + *			})
>> + *
>> + *			Name (PRT4, Package() {
>> + *				ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
>> + *				Package () {
>> + *					Package () { "port", 4 },
>> + *				},
>> + *				ToUUID("dbb8e3e6-5886-4ba6-8795-1319f52a966b"),
>> + *				Package () {
>> + *					Package () { "endpoint0", "EP40" },
>> + *				}
>> + *			})
>> + *
>> + *			Name (EP40, Package() {
>> + *				ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
>> + *				Package () {
>> + *					Package () { "endpoint", 0 },
>> + *					Package () {
>> + *						"remote-endpoint",
>> + *						Package () {
>> + *							\_SB.PCI0.I2C2.CAM0,
>> + *							0, 0
>> + *						}
>> + *					},
>> + *				}
>> + *			})
>> + *		}
>> + *	}

Please provide the equivalent DT structure as well. A large part of the
problem was lack of ACPI syntax understanding on my side.

>> + *
>> + * From the EP40 node under ISP device, you could parse the graph remote
>> + * endpoint using v4l2_fwnode_reference_get_int_prop with these arguments:
>> + *
>> + *  @fwnode: fwnode referring to EP40 under ISP.
>> + *  @prop: "remote-endpoint"
>> + *  @index: 0
>> + *  @props: "port", "endpoint"
>> + *  @nprops: 2
>> + *
>> + * And you'd get back fwnode referring to EP00 under CAM0.
>> + *
>> + * The same works the other way around: if you use EP00 under CAM0 as the
>> + * fwnode, you'll get fwnode referring to EP40 under ISP.
>> + *
>> + * Return: 0 on success
>> + *	   -ENOENT if no entries (or the property itself) were found
>> + *	   -EINVAL if property parsing otherwise failed
>> + *	   -ENOMEM if memory allocation failed
>> + */
>> +static struct fwnode_handle *v4l2_fwnode_reference_get_int_prop(
>> +	struct fwnode_handle *fwnode, const char *prop, unsigned int index,
>> +	const char **props, unsigned int nprops)
>> +{
>> +	struct fwnode_reference_args fwnode_args;
>> +	unsigned int *args = fwnode_args.args;
>> +	struct fwnode_handle *child;
>> +	int ret;
>> +
>> +	/*
>> +	 * Obtain remote fwnode as well as the integer arguments.
>> +	 *
>> +	 * Note that right now both -ENODATA and -ENOENT may signal
>> +	 * out-of-bounds access. Return -ENOENT in that case.
>> +	 */
>> +	ret = fwnode_property_get_reference_args(fwnode, prop, NULL, nprops,
>> +						 index, &fwnode_args);
>> +	if (ret)
>> +		return ERR_PTR(ret == -ENODATA ? -ENOENT : ret);
>> +
>> +	/*
>> +	 * Find a node in the tree under the referred fwnode corresponding to
>> +	 * the integer arguments.
>> +	 */
>> +	fwnode = fwnode_args.fwnode;
>> +	while (nprops--) {
>> +		u32 val;
>> +
>> +		/* Loop over all child nodes under fwnode. */
>> +		fwnode_for_each_child_node(fwnode, child) {
>> +			if (fwnode_property_read_u32(child, *props, &val))
>> +				continue;
>> +
>> +			/* Found property, see if its value matches. */
>> +			if (val == *args)
>> +				break;
>> +		}
>> +
>> +		fwnode_handle_put(fwnode);
>> +
>> +		/* No property found; return an error here. */
>> +		if (!child) {
>> +			fwnode = ERR_PTR(-ENOENT);
>> +			break;
>> +		}
>> +
>> +		props++;
>> +		args++;
>> +		fwnode = child;
>> +	}
>> +
>> +	return fwnode;
>> +}
>> +
>> +/*
>> + * v4l2_fwnode_reference_parse_int_props - parse references for async sub-devices
>> + * @dev: struct device pointer
>> + * @notifier: notifier for @dev
>> + * @prop: the name of the property
>> + * @props: the array of integer property names
>> + * @nprops: the number of integer properties
>> + *
>> + * Use v4l2_fwnode_reference_get_int_prop to find fwnodes through reference in
>> + * property @prop with integer arguments with child nodes matching in properties
>> + * @props. Then, set up V4L2 async sub-devices for those fwnodes in the notifier
>> + * accordingly.
>> + *
>> + * While it is technically possible to use this function on DT, it is only
>> + * meaningful on ACPI. On Device tree you can refer to any node in the tree but
>> + * on ACPI the references are limited to devices.
>> + *
>> + * Return: 0 on success
>> + *	   -ENOENT if no entries (or the property itself) were found
>> + *	   -EINVAL if property parsing otherwisefailed
>> + *	   -ENOMEM if memory allocation failed
>> + */
>> +static int v4l2_fwnode_reference_parse_int_props(
>> +	struct device *dev, struct v4l2_async_notifier *notifier,
>> +	const char *prop, const char **props, unsigned int nprops)
>> +{
>> +	struct fwnode_handle *fwnode;
>> +	unsigned int index;
>> +	int ret;
>> +
>> +	for (index = 0; !IS_ERR((fwnode = v4l2_fwnode_reference_get_int_prop(
>> +					 dev_fwnode(dev), prop, index, props,
>> +					 nprops))); index++)
>> +		fwnode_handle_put(fwnode);
>> +
>> +	/*
>> +	 * Note that right now both -ENODATA and -ENOENT may signal
>> +	 * out-of-bounds access. Return the error in cases other than that.
>> +	 */
>> +	if (PTR_ERR(fwnode) != -ENOENT && PTR_ERR(fwnode) != -ENODATA)
>> +		return PTR_ERR(fwnode);
>> +
>> +	ret = v4l2_async_notifier_realloc(notifier,
>> +					  notifier->num_subdevs + index);
>> +	if (ret)
>> +		return -ENOMEM;
>> +
>> +	for (index = 0; !IS_ERR((fwnode = v4l2_fwnode_reference_get_int_prop(
>> +					 dev_fwnode(dev), prop, index, props,
>> +					 nprops))); index++) {
>> +		struct v4l2_async_subdev *asd;
>> +
>> +		if (WARN_ON(notifier->num_subdevs >= notifier->max_subdevs)) {
>> +			ret = -EINVAL;
>> +			goto error;
>> +		}
>> +
>> +		asd = kzalloc(sizeof(struct v4l2_async_subdev), GFP_KERNEL);
>> +		if (!asd) {
>> +			ret = -ENOMEM;
>> +			goto error;
>> +		}
>> +
>> +		notifier->subdevs[notifier->num_subdevs] = asd;
>> +		asd->match.fwnode.fwnode = fwnode;
>> +		asd->match_type = V4L2_ASYNC_MATCH_FWNODE;
>> +		notifier->num_subdevs++;
>> +	}
>> +
>> +	return PTR_ERR(fwnode) == -ENOENT ? 0 : PTR_ERR(fwnode);
>> +
>> +error:
>> +	fwnode_handle_put(fwnode);
>> +	return ret;
>> +}
>> +
>>  MODULE_LICENSE("GPL");
>>  MODULE_AUTHOR("Sakari Ailus <sakari.ailus@linux.intel.com>");
>>  MODULE_AUTHOR("Sylwester Nawrocki <s.nawrocki@samsung.com>");
>> -- 
>> 2.11.0
>>
> 

Regards,

	Hans

Re: [PATCH v15.1 24/32] v4l: fwnode: Add a helper function to obtain device / integer references

[Sakari Ailus]

Hi Hans,

On Thu, Oct 19, 2017 at 08:52:22AM +0200, Hans Verkuil wrote:
> On 10/18/2017 05:32 PM, Sakari Ailus wrote:
> > On Wed, Oct 18, 2017 at 04:56:56PM +0300, Sakari Ailus wrote:
> >> v4l2_fwnode_reference_parse_int_prop() will find an fwnode such that under
> >> the device's own fwnode, it will follow child fwnodes with the given
> >> property-value pair and return the resulting fwnode.
> >>
> >> Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
> >> ---
> >> since v15:
> >>
> >> - Use a graph example instead of a LED one; this way nprops will be 2.
> >>
> >>  drivers/media/v4l2-core/v4l2-fwnode.c | 252 ++++++++++++++++++++++++++++++++++
> >>  1 file changed, 252 insertions(+)
> >>
> >> diff --git a/drivers/media/v4l2-core/v4l2-fwnode.c b/drivers/media/v4l2-core/v4l2-fwnode.c
> >> index edd2e8d983a1..989a6f8a09fa 100644
> >> --- a/drivers/media/v4l2-core/v4l2-fwnode.c
> >> +++ b/drivers/media/v4l2-core/v4l2-fwnode.c
> >> @@ -578,6 +578,258 @@ static int v4l2_fwnode_reference_parse(
> >>  	return ret;
> >>  }
> >>  
> >> +/*
> >> + * v4l2_fwnode_reference_get_int_prop - parse a reference with integer
> >> + *					arguments
> >> + * @fwnode: fwnode to read @prop from
> >> + * @notifier: notifier for @dev
> >> + * @prop: the name of the property
> >> + * @index: the index of the reference to get
> >> + * @props: the array of integer property names
> >> + * @nprops: the number of integer property names in @nprops
> >> + *
> >> + * First find an fwnode referred to by the reference at @index in @prop.
> >> + *
> >> + * Then under that fwnode, @nprops times, for each property in @props,
> >> + * iteratively follow child nodes starting from fwnode such that they have the
> >> + * property in @props array at the index of the child node distance from the
> >> + * root node and the value of that property matching with the integer argument
> >> + * of the reference, at the same index.
> >> + *
> >> + * The child fwnode reched at the end of the iteration is then returned to the
> >> + * caller.
> > 
> > An alternative to these three paragraphs could be:
> > 
> > First obtain an fwnode, with integer arguments, referred to by the reference
> > at @index in @prop. These shall be referred as "remote fwnode" and "remote
> > fwnode arguments".
> > 
> > Under the remote fwnode, perform the following steps iteratively @nprops
> > times. Let the number of iteration be "i", starting from 0.
> > 
> > 1. Designate the remote fwnode as the "current fwnode".
> > 
> > 2. Begin iterating child fwnodes under the current fwnode.
> > 
> > 3. Find next child fwnode under the current fwnode. If no node is found,
> >    return NULL.
> > 
> > 4. From the child fwnode, read 32-bit unsigned integer property named as
> >    the i'th element in @props array.
> > 
> > 5. Compare the value of that integer property with the i'th element in the
> >    remote fwnode argument array. If the values do not match, go to (3).
> > 
> > 6. Increment i by one. If i matches with @nprops, return the child fwnode.
> > 
> > 7. Designate the child fwnode as the current fwnode and continue from (2).
> 
> This is definitely a better text.
> 
> However, this describes the mechanics of the function, not what its purpose
> actually is.
> 
> The core reason for this is that you cannot refer to just any node in ACPI.
> So to refer to an endpoint (easy in DT) you need to refer to a device, then
> provide a list of (property name, property value) tuples where each tuple
> uniquely identifies a child node. The first tuple identifies a child directly
> underneath the device fwnode, the next tuple identifies a child node underneath
> the fwnode identified by the previous tuple, etc. until you reached the fwnode
> you need.
> 
> Does this make sense?

I'm fine with using the above text. The function will move out of V4L2
probably quite soon and the documentation in the ACPI framework will likely
be different from whatever we end up using here anyway.

> 
> > 
> >> + *
> >> + * An example with a graph, as defined in Documentation/acpi/dsd/graph.txt:
> >> + *
> >> + *	Scope (\_SB.PCI0.I2C2)
> >> + *	{
> >> + *		Device (CAM0)
> >> + *		{
> >> + *			Name (_DSD, Package () {
> >> + *				ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
> >> + *				Package () {
> >> + *					Package () {
> >> + *						"compatible",
> >> + *						Package () { "nokia,smia" }
> >> + *					},
> >> + *				},
> >> + *				ToUUID("dbb8e3e6-5886-4ba6-8795-1319f52a966b"),
> >> + *				Package () {
> >> + *					Package () { "port0", "PRT0" },
> >> + *				}
> >> + *			})
> >> + *			Name (PRT0, Package() {
> >> + *				ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
> >> + *				Package () {
> >> + *					Package () { "port", 0 },
> >> + *				},
> >> + *				ToUUID("dbb8e3e6-5886-4ba6-8795-1319f52a966b"),
> >> + *				Package () {
> >> + *					Package () { "endpoint0", "EP00" },
> >> + *				}
> >> + *			})
> >> + *			Name (EP00, Package() {
> >> + *				ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
> >> + *				Package () {
> >> + *					Package () { "endpoint", 0 },
> >> + *					Package () {
> >> + *						"remote-endpoint",
> >> + *						Package() {
> >> + *							\_SB.PCI0.ISP, 4, 0
> >> + *						}
> >> + *					},
> >> + *				}
> >> + *			})
> >> + *		}
> >> + *	}
> >> + *
> >> + *	Scope (\_SB.PCI0)
> >> + *	{
> >> + *		Device (ISP)
> >> + *		{
> >> + *			Name (_DSD, Package () {
> >> + *				ToUUID("dbb8e3e6-5886-4ba6-8795-1319f52a966b"),
> >> + *				Package () {
> >> + *					Package () { "port4", "PRT4" },
> >> + *				}
> >> + *			})
> >> + *
> >> + *			Name (PRT4, Package() {
> >> + *				ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
> >> + *				Package () {
> >> + *					Package () { "port", 4 },
> >> + *				},
> >> + *				ToUUID("dbb8e3e6-5886-4ba6-8795-1319f52a966b"),
> >> + *				Package () {
> >> + *					Package () { "endpoint0", "EP40" },
> >> + *				}
> >> + *			})
> >> + *
> >> + *			Name (EP40, Package() {
> >> + *				ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
> >> + *				Package () {
> >> + *					Package () { "endpoint", 0 },
> >> + *					Package () {
> >> + *						"remote-endpoint",
> >> + *						Package () {
> >> + *							\_SB.PCI0.I2C2.CAM0,
> >> + *							0, 0
> >> + *						}
> >> + *					},
> >> + *				}
> >> + *			})
> >> + *		}
> >> + *	}
> 
> Please provide the equivalent DT structure as well. A large part of the
> problem was lack of ACPI syntax understanding on my side.

Yes, I'll add that.

> 
> >> + *
> >> + * From the EP40 node under ISP device, you could parse the graph remote
> >> + * endpoint using v4l2_fwnode_reference_get_int_prop with these arguments:
> >> + *
> >> + *  @fwnode: fwnode referring to EP40 under ISP.
> >> + *  @prop: "remote-endpoint"
> >> + *  @index: 0
> >> + *  @props: "port", "endpoint"
> >> + *  @nprops: 2
> >> + *
> >> + * And you'd get back fwnode referring to EP00 under CAM0.
> >> + *
> >> + * The same works the other way around: if you use EP00 under CAM0 as the
> >> + * fwnode, you'll get fwnode referring to EP40 under ISP.
> >> + *
> >> + * Return: 0 on success
> >> + *	   -ENOENT if no entries (or the property itself) were found
> >> + *	   -EINVAL if property parsing otherwise failed
> >> + *	   -ENOMEM if memory allocation failed
> >> + */
> >> +static struct fwnode_handle *v4l2_fwnode_reference_get_int_prop(
> >> +	struct fwnode_handle *fwnode, const char *prop, unsigned int index,
> >> +	const char **props, unsigned int nprops)
> >> +{
> >> +	struct fwnode_reference_args fwnode_args;
> >> +	unsigned int *args = fwnode_args.args;
> >> +	struct fwnode_handle *child;
> >> +	int ret;
> >> +
> >> +	/*
> >> +	 * Obtain remote fwnode as well as the integer arguments.
> >> +	 *
> >> +	 * Note that right now both -ENODATA and -ENOENT may signal
> >> +	 * out-of-bounds access. Return -ENOENT in that case.
> >> +	 */
> >> +	ret = fwnode_property_get_reference_args(fwnode, prop, NULL, nprops,
> >> +						 index, &fwnode_args);
> >> +	if (ret)
> >> +		return ERR_PTR(ret == -ENODATA ? -ENOENT : ret);
> >> +
> >> +	/*
> >> +	 * Find a node in the tree under the referred fwnode corresponding to
> >> +	 * the integer arguments.
> >> +	 */
> >> +	fwnode = fwnode_args.fwnode;
> >> +	while (nprops--) {
> >> +		u32 val;
> >> +
> >> +		/* Loop over all child nodes under fwnode. */
> >> +		fwnode_for_each_child_node(fwnode, child) {
> >> +			if (fwnode_property_read_u32(child, *props, &val))
> >> +				continue;
> >> +
> >> +			/* Found property, see if its value matches. */
> >> +			if (val == *args)
> >> +				break;
> >> +		}
> >> +
> >> +		fwnode_handle_put(fwnode);
> >> +
> >> +		/* No property found; return an error here. */
> >> +		if (!child) {
> >> +			fwnode = ERR_PTR(-ENOENT);
> >> +			break;
> >> +		}
> >> +
> >> +		props++;
> >> +		args++;
> >> +		fwnode = child;
> >> +	}
> >> +
> >> +	return fwnode;
> >> +}
> >> +
> >> +/*
> >> + * v4l2_fwnode_reference_parse_int_props - parse references for async sub-devices
> >> + * @dev: struct device pointer
> >> + * @notifier: notifier for @dev
> >> + * @prop: the name of the property
> >> + * @props: the array of integer property names
> >> + * @nprops: the number of integer properties
> >> + *
> >> + * Use v4l2_fwnode_reference_get_int_prop to find fwnodes through reference in
> >> + * property @prop with integer arguments with child nodes matching in properties
> >> + * @props. Then, set up V4L2 async sub-devices for those fwnodes in the notifier
> >> + * accordingly.
> >> + *
> >> + * While it is technically possible to use this function on DT, it is only
> >> + * meaningful on ACPI. On Device tree you can refer to any node in the tree but
> >> + * on ACPI the references are limited to devices.
> >> + *
> >> + * Return: 0 on success
> >> + *	   -ENOENT if no entries (or the property itself) were found
> >> + *	   -EINVAL if property parsing otherwisefailed
> >> + *	   -ENOMEM if memory allocation failed
> >> + */
> >> +static int v4l2_fwnode_reference_parse_int_props(
> >> +	struct device *dev, struct v4l2_async_notifier *notifier,
> >> +	const char *prop, const char **props, unsigned int nprops)
> >> +{
> >> +	struct fwnode_handle *fwnode;
> >> +	unsigned int index;
> >> +	int ret;
> >> +
> >> +	for (index = 0; !IS_ERR((fwnode = v4l2_fwnode_reference_get_int_prop(
> >> +					 dev_fwnode(dev), prop, index, props,
> >> +					 nprops))); index++)
> >> +		fwnode_handle_put(fwnode);
> >> +
> >> +	/*
> >> +	 * Note that right now both -ENODATA and -ENOENT may signal
> >> +	 * out-of-bounds access. Return the error in cases other than that.
> >> +	 */
> >> +	if (PTR_ERR(fwnode) != -ENOENT && PTR_ERR(fwnode) != -ENODATA)
> >> +		return PTR_ERR(fwnode);
> >> +
> >> +	ret = v4l2_async_notifier_realloc(notifier,
> >> +					  notifier->num_subdevs + index);
> >> +	if (ret)
> >> +		return -ENOMEM;
> >> +
> >> +	for (index = 0; !IS_ERR((fwnode = v4l2_fwnode_reference_get_int_prop(
> >> +					 dev_fwnode(dev), prop, index, props,
> >> +					 nprops))); index++) {
> >> +		struct v4l2_async_subdev *asd;
> >> +
> >> +		if (WARN_ON(notifier->num_subdevs >= notifier->max_subdevs)) {
> >> +			ret = -EINVAL;
> >> +			goto error;
> >> +		}
> >> +
> >> +		asd = kzalloc(sizeof(struct v4l2_async_subdev), GFP_KERNEL);
> >> +		if (!asd) {
> >> +			ret = -ENOMEM;
> >> +			goto error;
> >> +		}
> >> +
> >> +		notifier->subdevs[notifier->num_subdevs] = asd;
> >> +		asd->match.fwnode.fwnode = fwnode;
> >> +		asd->match_type = V4L2_ASYNC_MATCH_FWNODE;
> >> +		notifier->num_subdevs++;
> >> +	}
> >> +
> >> +	return PTR_ERR(fwnode) == -ENOENT ? 0 : PTR_ERR(fwnode);
> >> +
> >> +error:
> >> +	fwnode_handle_put(fwnode);
> >> +	return ret;
> >> +}
> >> +
> >>  MODULE_LICENSE("GPL");
> >>  MODULE_AUTHOR("Sakari Ailus <sakari.ailus@linux.intel.com>");
> >>  MODULE_AUTHOR("Sylwester Nawrocki <s.nawrocki@samsung.com>");
> >> -- 
> >> 2.11.0
> >>
> > 
> 
> Regards,
> 
> 	Hans

-- 
Sakari Ailus
e-mail: sakari.ailus@iki.fi

[PATCH v15.2 24/32] v4l: fwnode: Add a helper function to obtain device / integer references

[Sakari Ailus]

v4l2_fwnode_reference_parse_int_prop() will find an fwnode such that under
the device's own fwnode, it will follow child fwnodes with the given
property-value pair and return the resulting fwnode.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
---
 drivers/media/v4l2-core/v4l2-fwnode.c | 286 ++++++++++++++++++++++++++++++++++
 1 file changed, 286 insertions(+)

diff --git a/drivers/media/v4l2-core/v4l2-fwnode.c b/drivers/media/v4l2-core/v4l2-fwnode.c
index edd2e8d983a1..ed7e363a8a6a 100644
--- a/drivers/media/v4l2-core/v4l2-fwnode.c
+++ b/drivers/media/v4l2-core/v4l2-fwnode.c
@@ -578,6 +578,292 @@ static int v4l2_fwnode_reference_parse(
 	return ret;
 }
 
+/*
+ * v4l2_fwnode_reference_get_int_prop - parse a reference with integer
+ *					arguments
+ * @fwnode: fwnode to read @prop from
+ * @notifier: notifier for @dev
+ * @prop: the name of the property
+ * @index: the index of the reference to get
+ * @props: the array of integer property names
+ * @nprops: the number of integer property names in @nprops
+ *
+ * First find an fwnode referred to by the reference at @index in @prop.
+ *
+ * Then under that fwnode, @nprops times, for each property in @props,
+ * iteratively follow child nodes starting from fwnode such that they have the
+ * property in @props array at the index of the child node distance from the
+ * root node and the value of that property matching with the integer argument
+ * of the reference, at the same index.
+ *
+ * The child fwnode reched at the end of the iteration is then returned to the
+ * caller.
+ *
+ * The core reason for this is that you cannot refer to just any node in ACPI.
+ * So to refer to an endpoint (easy in DT) you need to refer to a device, then
+ * provide a list of (property name, property value) tuples where each tuple
+ * uniquely identifies a child node. The first tuple identifies a child directly
+ * underneath the device fwnode, the next tuple identifies a child node
+ * underneath the fwnode identified by the previous tuple, etc. until you
+ * reached the fwnode you need.
+ *
+ * An example with a graph, as defined in Documentation/acpi/dsd/graph.txt:
+ *
+ *	Scope (\_SB.PCI0.I2C2)
+ *	{
+ *		Device (CAM0)
+ *		{
+ *			Name (_DSD, Package () {
+ *				ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
+ *				Package () {
+ *					Package () {
+ *						"compatible",
+ *						Package () { "nokia,smia" }
+ *					},
+ *				},
+ *				ToUUID("dbb8e3e6-5886-4ba6-8795-1319f52a966b"),
+ *				Package () {
+ *					Package () { "port0", "PRT0" },
+ *				}
+ *			})
+ *			Name (PRT0, Package() {
+ *				ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
+ *				Package () {
+ *					Package () { "port", 0 },
+ *				},
+ *				ToUUID("dbb8e3e6-5886-4ba6-8795-1319f52a966b"),
+ *				Package () {
+ *					Package () { "endpoint0", "EP00" },
+ *				}
+ *			})
+ *			Name (EP00, Package() {
+ *				ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
+ *				Package () {
+ *					Package () { "endpoint", 0 },
+ *					Package () {
+ *						"remote-endpoint",
+ *						Package() {
+ *							\_SB.PCI0.ISP, 4, 0
+ *						}
+ *					},
+ *				}
+ *			})
+ *		}
+ *	}
+ *
+ *	Scope (\_SB.PCI0)
+ *	{
+ *		Device (ISP)
+ *		{
+ *			Name (_DSD, Package () {
+ *				ToUUID("dbb8e3e6-5886-4ba6-8795-1319f52a966b"),
+ *				Package () {
+ *					Package () { "port4", "PRT4" },
+ *				}
+ *			})
+ *
+ *			Name (PRT4, Package() {
+ *				ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
+ *				Package () {
+ *					Package () { "port", 4 },
+ *				},
+ *				ToUUID("dbb8e3e6-5886-4ba6-8795-1319f52a966b"),
+ *				Package () {
+ *					Package () { "endpoint0", "EP40" },
+ *				}
+ *			})
+ *
+ *			Name (EP40, Package() {
+ *				ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
+ *				Package () {
+ *					Package () { "endpoint", 0 },
+ *					Package () {
+ *						"remote-endpoint",
+ *						Package () {
+ *							\_SB.PCI0.I2C2.CAM0,
+ *							0, 0
+ *						}
+ *					},
+ *				}
+ *			})
+ *		}
+ *	}
+ *
+ * From the EP40 node under ISP device, you could parse the graph remote
+ * endpoint using v4l2_fwnode_reference_get_int_prop with these arguments:
+ *
+ *  @fwnode: fwnode referring to EP40 under ISP.
+ *  @prop: "remote-endpoint"
+ *  @index: 0
+ *  @props: "port", "endpoint"
+ *  @nprops: 2
+ *
+ * And you'd get back fwnode referring to EP00 under CAM0.
+ *
+ * The same works the other way around: if you use EP00 under CAM0 as the
+ * fwnode, you'll get fwnode referring to EP40 under ISP.
+ *
+ * The same example in DT syntax would look like this:
+ *
+ * cam: cam0 {
+ *	compatible = "nokia,smia";
+ *
+ *	port {
+ *		port = <0>;
+ *		endpoint {
+ *			endpoint = <0>;
+ *			remote-endpoint = <&isp 4 0>;
+ *		};
+ *	};
+ * };
+ *
+ * isp: isp {
+ *	ports {
+ *		port@4 {
+ *			port = <4>;
+ *			endpoint {
+ *				endpoint = <0>;
+ *				remote-endpoint = <&cam 0 0>;
+ *			};
+ *		};
+ *	};
+ * };
+ *
+ * Return: 0 on success
+ *	   -ENOENT if no entries (or the property itself) were found
+ *	   -EINVAL if property parsing otherwise failed
+ *	   -ENOMEM if memory allocation failed
+ */
+static struct fwnode_handle *v4l2_fwnode_reference_get_int_prop(
+	struct fwnode_handle *fwnode, const char *prop, unsigned int index,
+	const char **props, unsigned int nprops)
+{
+	struct fwnode_reference_args fwnode_args;
+	unsigned int *args = fwnode_args.args;
+	struct fwnode_handle *child;
+	int ret;
+
+	/*
+	 * Obtain remote fwnode as well as the integer arguments.
+	 *
+	 * Note that right now both -ENODATA and -ENOENT may signal
+	 * out-of-bounds access. Return -ENOENT in that case.
+	 */
+	ret = fwnode_property_get_reference_args(fwnode, prop, NULL, nprops,
+						 index, &fwnode_args);
+	if (ret)
+		return ERR_PTR(ret == -ENODATA ? -ENOENT : ret);
+
+	/*
+	 * Find a node in the tree under the referred fwnode corresponding to
+	 * the integer arguments.
+	 */
+	fwnode = fwnode_args.fwnode;
+	while (nprops--) {
+		u32 val;
+
+		/* Loop over all child nodes under fwnode. */
+		fwnode_for_each_child_node(fwnode, child) {
+			if (fwnode_property_read_u32(child, *props, &val))
+				continue;
+
+			/* Found property, see if its value matches. */
+			if (val == *args)
+				break;
+		}
+
+		fwnode_handle_put(fwnode);
+
+		/* No property found; return an error here. */
+		if (!child) {
+			fwnode = ERR_PTR(-ENOENT);
+			break;
+		}
+
+		props++;
+		args++;
+		fwnode = child;
+	}
+
+	return fwnode;
+}
+
+/*
+ * v4l2_fwnode_reference_parse_int_props - parse references for async sub-devices
+ * @dev: struct device pointer
+ * @notifier: notifier for @dev
+ * @prop: the name of the property
+ * @props: the array of integer property names
+ * @nprops: the number of integer properties
+ *
+ * Use v4l2_fwnode_reference_get_int_prop to find fwnodes through reference in
+ * property @prop with integer arguments with child nodes matching in properties
+ * @props. Then, set up V4L2 async sub-devices for those fwnodes in the notifier
+ * accordingly.
+ *
+ * While it is technically possible to use this function on DT, it is only
+ * meaningful on ACPI. On Device tree you can refer to any node in the tree but
+ * on ACPI the references are limited to devices.
+ *
+ * Return: 0 on success
+ *	   -ENOENT if no entries (or the property itself) were found
+ *	   -EINVAL if property parsing otherwisefailed
+ *	   -ENOMEM if memory allocation failed
+ */
+static int v4l2_fwnode_reference_parse_int_props(
+	struct device *dev, struct v4l2_async_notifier *notifier,
+	const char *prop, const char **props, unsigned int nprops)
+{
+	struct fwnode_handle *fwnode;
+	unsigned int index;
+	int ret;
+
+	for (index = 0; !IS_ERR((fwnode = v4l2_fwnode_reference_get_int_prop(
+					 dev_fwnode(dev), prop, index, props,
+					 nprops))); index++)
+		fwnode_handle_put(fwnode);
+
+	/*
+	 * Note that right now both -ENODATA and -ENOENT may signal
+	 * out-of-bounds access. Return the error in cases other than that.
+	 */
+	if (PTR_ERR(fwnode) != -ENOENT && PTR_ERR(fwnode) != -ENODATA)
+		return PTR_ERR(fwnode);
+
+	ret = v4l2_async_notifier_realloc(notifier,
+					  notifier->num_subdevs + index);
+	if (ret)
+		return -ENOMEM;
+
+	for (index = 0; !IS_ERR((fwnode = v4l2_fwnode_reference_get_int_prop(
+					 dev_fwnode(dev), prop, index, props,
+					 nprops))); index++) {
+		struct v4l2_async_subdev *asd;
+
+		if (WARN_ON(notifier->num_subdevs >= notifier->max_subdevs)) {
+			ret = -EINVAL;
+			goto error;
+		}
+
+		asd = kzalloc(sizeof(struct v4l2_async_subdev), GFP_KERNEL);
+		if (!asd) {
+			ret = -ENOMEM;
+			goto error;
+		}
+
+		notifier->subdevs[notifier->num_subdevs] = asd;
+		asd->match.fwnode.fwnode = fwnode;
+		asd->match_type = V4L2_ASYNC_MATCH_FWNODE;
+		notifier->num_subdevs++;
+	}
+
+	return PTR_ERR(fwnode) == -ENOENT ? 0 : PTR_ERR(fwnode);
+
+error:
+	fwnode_handle_put(fwnode);
+	return ret;
+}
+
 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Sakari Ailus <sakari.ailus@linux.intel.com>");
 MODULE_AUTHOR("Sylwester Nawrocki <s.nawrocki@samsung.com>");
-- 
2.11.0

Re: [PATCH v15.2 24/32] v4l: fwnode: Add a helper function to obtain device / integer references

[Sakari Ailus]

On Tue, Oct 24, 2017 at 11:32:54PM +0300, Sakari Ailus wrote:
> v4l2_fwnode_reference_parse_int_prop() will find an fwnode such that under
> the device's own fwnode, it will follow child fwnodes with the given
> property-value pair and return the resulting fwnode.
> 
> Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
> ---

since v15.1:

- Add DT example.

- Add textual description as suggested by Hans.


-- 
Sakari Ailus
e-mail: sakari.ailus@iki.fi

Re: [PATCH v15.2 24/32] v4l: fwnode: Add a helper function to obtain device / integer references

[Hans Verkuil]

On 10/24/2017 10:32 PM, Sakari Ailus wrote:
> v4l2_fwnode_reference_parse_int_prop() will find an fwnode such that under
> the device's own fwnode, it will follow child fwnodes with the given
> property-value pair and return the resulting fwnode.
> 
> Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>

The improved explanation and the DT example make this much easier to understand,
so:

Acked-by: Hans Verkuil <hans.verkuil@cisco.com>

Thanks!

	Hans