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media: imx: Switch to subdev notifiers

PATCH New Steve Longerbeam 1 participant 5 messages Sep 29, 2018 – Sep 30, 2018

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#0 lore raw

v7 cover media: imx: Switch to subdev notifiers

This patchset converts the imx-media driver and its dependent subdevs to use subdev notifiers.

There are a couple shortcomings in v4l2-core that prevented subdev notifiers from working correctly in imx-media:

1. v4l2_async_notifier_fwnode_parse_endpoint() treats a fwnode endpoint that is not connected to a remote device as an error. But in the case of the video-mux subdev, this is not an error, it is OK if some of the mux inputs have no connection. Also, Documentation/devicetree/bindings/media/video-interfaces.txt explicitly states that the 'remote-endpoint' property is optional. So the first patch is a small modification to ignore empty endpoints in v4l2_async_notifier_fwnode_parse_endpoint() and allow __v4l2_async_notifier_parse_fwnode_endpoints() to continue to parse the remaining port endpoints of the device.

2. In the imx-media graph, multiple subdevs will encounter the same upstream subdev (such as the imx6-mipi-csi2 receiver), and so v4l2_async_notifier_parse_fwnode_endpoints() will add imx6-mipi-csi2 multiple times. This is treated as an error by v4l2_async_notifier_register() later.

To get around this problem, add an v4l2_async_notifier_add_subdev() which first verifies the provided asd does not already exist in the given notifier asd list or in other registered notifiers. If the asd exists, the function returns -EEXIST and it's up to the caller to decide if that is an error (in imx-media case it is never an error).

Patches 2-5 deal with adding that support.

3. Patch 6 adds v4l2_async_register_fwnode_subdev(), which is a convenience function for parsing a subdev's fwnode port endpoints for connected remote subdevs, registering a subdev notifier, and then registering the sub-device itself.

4. Patches 7-14 update the subdev drivers to register a subdev notifier with endpoint parsing, and the changes to imx-media to support that.

5. Finally, the last 3 patches endeavor to completely remove support for the notifier->subdevs[] array in platform drivers and v4l2 core. All platform drivers are modified to make use of v4l2_async_notifier_add_subdev() and its related convenience functions to add asd's to the notifier @asd_list, and any allocation or reference to the notifier->subdevs[] array removed. After that large patch, notifier->subdevs[] array is stripped from v4l2-async and v4l2-subdev docs are updated to reflect the new method of adding asd's to notifiers.

Patches 07-14 (video-mux and the imx patches) are

Patches 01-14 are

on i.MX6 with Toshiba TC358743 connected via MIPI CSI-2.

History:

v7:
- Comment, error message, and whitespace fixes in patch 02/17. Suggested by Mauro Chehab.
- Fixed merge conflict in drivers/media/platform/ti-vpe/cal.c.
- Make patch author and SoB email addresses the same.

v6:
- Export v4l2_async_notifier_init(), which must be called by all drivers before the first call to v4l2_async_notifier_add_subdev(). Suggested by Sakari Ailus.
- Removed @num_subdevs from struct v4l2_async_notifier, and the macro V4L2_MAX_SUBDEVS. Sugested by Sakari.
- Fixed a double device node put in vpif_capture.c. Reported by Sakari.
- Fixed wrong printk format qualifiers in xilinx-vipp.c. Reported by Dan Carpenter.

v5:
- see point 5 above.

v4:
- small non-functional code cleanup in video-mux.c.
- strip TODO for comparing custom asd's for equivalence.
- add three more convenience functions: v4l2_async_notifier_add_fwnode_subdev, v4l2_async_notifier_add_i2c_subdev, v4l2_async_notifier_add_devname_subdev.
- strip support in v4l2_async_register_fwnode_subdev for sub-devices that register from port nodes.

v3:
- code optimization in asd_equal(), and remove unneeded braces, suggested by Sakari Ailus.
- add a NULL asd pointer check to v4l2_async_notifier_asd_valid().
- fix an error-out path in v4l2_async_register_fwnode_subdev() that forgot to put device.

v2:
- don't pass an empty endpoint to the parse_endpoint callback, v4l2_async_notifier_fwnode_parse_endpoint() now just ignores them and returns success.
- Fix a couple compile warnings and errors seen in i386 and sh archs.

Steve Longerbeam (17):
media: v4l2-fwnode: ignore endpoints that have no remote port parent
media: v4l2: async: Allow searching for asd of any type
media: v4l2: async: Add v4l2_async_notifier_add_subdev
media: v4l2: async: Add convenience functions to allocate and add
asd's
media: v4l2-fwnode: Switch to v4l2_async_notifier_add_subdev
media: v4l2-fwnode: Add a convenience function for registering subdevs
with notifiers
media: platform: video-mux: Register a subdev notifier
media: imx: csi: Register a subdev notifier
media: imx: mipi csi-2: Register a subdev notifier
media: staging/imx: of: Remove recursive graph walk
media: staging/imx: Loop through all registered subdevs for media
links
media: staging/imx: Rename root notifier
media: staging/imx: Switch to v4l2_async_notifier_add_*_subdev
media: staging/imx: TODO: Remove one assumption about OF graph parsing
media: platform: Switch to v4l2_async_notifier_add_subdev
media: v4l2: async: Remove notifier subdevs array
[media] v4l2-subdev.rst: Update doc regarding subdev descriptors

 Documentation/media/kapi/v4l2-subdev.rst      |  30 +-
 drivers/media/pci/intel/ipu3/ipu3-cio2.c      |  14 +-
 drivers/media/platform/Kconfig                |   1 +
 drivers/media/platform/am437x/am437x-vpfe.c   |  82 +++---
 drivers/media/platform/atmel/atmel-isc.c      |  15 +-
 drivers/media/platform/atmel/atmel-isi.c      |  17 +-
 drivers/media/platform/cadence/cdns-csi2rx.c  |  28 +-
 drivers/media/platform/davinci/vpif_capture.c |  71 ++---
 drivers/media/platform/davinci/vpif_display.c |  20 +-
 drivers/media/platform/exynos4-is/media-dev.c |  32 ++-
 drivers/media/platform/exynos4-is/media-dev.h |   1 -
 drivers/media/platform/omap3isp/isp.c         |   1 +
 drivers/media/platform/pxa_camera.c           |  25 +-
 drivers/media/platform/qcom/camss/camss.c     |  89 +++---
 drivers/media/platform/qcom/camss/camss.h     |   2 +-
 drivers/media/platform/rcar-vin/rcar-core.c   |   6 +-
 drivers/media/platform/rcar-vin/rcar-csi2.c   |  22 +-
 drivers/media/platform/rcar_drif.c            |  18 +-
 drivers/media/platform/renesas-ceu.c          |  53 ++--
 .../media/platform/soc_camera/soc_camera.c    |  35 ++-
 drivers/media/platform/stm32/stm32-dcmi.c     |  24 +-
 drivers/media/platform/ti-vpe/cal.c           |  33 ++-
 drivers/media/platform/video-mux.c            |  36 ++-
 drivers/media/platform/xilinx/xilinx-vipp.c   | 173 ++++++-----
 drivers/media/platform/xilinx/xilinx-vipp.h   |   4 -
 drivers/media/v4l2-core/v4l2-async.c          | 268 +++++++++++++-----
 drivers/media/v4l2-core/v4l2-fwnode.c         | 198 ++++++-------
 drivers/staging/media/imx/TODO                |  29 +-
 drivers/staging/media/imx/imx-media-csi.c     |  57 +++-
 drivers/staging/media/imx/imx-media-dev.c     | 145 +++-------
 .../staging/media/imx/imx-media-internal-sd.c |   5 +-
 drivers/staging/media/imx/imx-media-of.c      | 106 +------
 drivers/staging/media/imx/imx-media.h         |   6 +-
 drivers/staging/media/imx/imx6-mipi-csi2.c    |  31 +-
 include/media/v4l2-async.h                    | 101 ++++++-
 include/media/v4l2-fwnode.h                   |  52 +++-
 36 files changed, 1038 insertions(+), 792 deletions(-)
Signature · 1 line
2.17.1
#1 lore raw

PATCH v7 1/17 media: v4l2-fwnode: ignore endpoints that have no remote port parent

Documentation/devicetree/bindings/media/video-interfaces.txt states that the 'remote-endpoint' property is optional.

So v4l2_async_notifier_fwnode_parse_endpoint() should not return error if the endpoint has no remote port parent. Just ignore the endpoint, skip adding an asd to the notifier and return 0. __v4l2_async_notifier_parse_fwnode_endpoints() will then continue parsing the remaining port endpoints of the device.

---
Changes since v6:
- none
Changes since v5:
- none
Changes since v4:
- none
Changes since v3:
- none
Changes since v2:
- none
Changes since v1:
- don't pass an empty endpoint to the parse_endpoint callback, v4l2_async_notifier_fwnode_parse_endpoint() now just ignores them and returns success. The current users of v4l2_async_notifier_parse_fwnode_endpoints() (omap3isp, rcar-vin, intel-ipu3) no longer need modification.

---
 drivers/media/v4l2-core/v4l2-fwnode.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
drivers/media/v4l2-core/v4l2-fwnode.c +1 -1
index 169bdbb1f61a..0b8c736b1606 100644
@@ -367,7 +367,7 @@ static int v4l2_async_notifier_fwnode_parse_endpoint(
 		fwnode_graph_get_remote_port_parent(endpoint);
 	if (!asd->match.fwnode) {
 		dev_warn(dev, "bad remote port parent\n");
-		ret = -EINVAL;
+		ret = -ENOTCONN;
 		goto out_err;
 	}
 
Signature · 1 line
2.17.1
#2 lore raw

PATCH v7 2/17 media: v4l2: async: Allow searching for asd of any type

In reply to Steve Longerbeam

Generalize v4l2_async_notifier_fwnode_has_async_subdev() to allow searching for any type of async subdev, not just fwnodes. Rename to v4l2_async_notifier_has_async_subdev() and pass it an asd pointer.

---
Changes since v6:
- elaborate on comment for asd_equal(), suggested by Mauro Chehab.
- whitespace checkpatch fixes, suggested by Mauro.
- made an error message more clear in __v4l2_async_notifier_register(), suggested by Mauro.
Changes since v5:
- none
Changes since v4:
- none
Changes since v3:
- removed TODO to support asd compare with CUSTOM match type in asd_equal().
Changes since v2:
- code optimization in asd_equal(), and remove unneeded braces, suggested by Sakari Ailus.
Changes since v1:
- none

---
 drivers/media/v4l2-core/v4l2-async.c | 77 +++++++++++++++++-----------
 1 file changed, 46 insertions(+), 31 deletions(-)
drivers/media/v4l2-core/v4l2-async.c +46 -31
index 2b08d03b251d..f09d354b96a0 100644
@@ -124,6 +124,31 @@ static struct v4l2_async_subdev *v4l2_async_find_match(
 	return NULL;
 }
 
+/* Compare two async sub-device descriptors for equivalence */
+static bool asd_equal(struct v4l2_async_subdev *asd_x,
+		      struct v4l2_async_subdev *asd_y)
+{
+	if (asd_x->match_type != asd_y->match_type)
+		return false;
+
+	switch (asd_x->match_type) {
+	case V4L2_ASYNC_MATCH_DEVNAME:
+		return strcmp(asd_x->match.device_name,
+			      asd_y->match.device_name) == 0;
+	case V4L2_ASYNC_MATCH_I2C:
+		return asd_x->match.i2c.adapter_id ==
+			asd_y->match.i2c.adapter_id &&
+			asd_x->match.i2c.address ==
+			asd_y->match.i2c.address;
+	case V4L2_ASYNC_MATCH_FWNODE:
+		return asd_x->match.fwnode == asd_y->match.fwnode;
+	default:
+		break;
+	}
+
+	return false;
+}
+
 /* 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)
@@ -308,29 +333,23 @@ 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)
+/* See if an async sub-device can be found in a notifier's lists. */
+static bool
+__v4l2_async_notifier_has_async_subdev(struct v4l2_async_notifier *notifier,
+				       struct v4l2_async_subdev *asd)
 {
-	struct v4l2_async_subdev *asd;
+	struct v4l2_async_subdev *asd_y;
 	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)
+	list_for_each_entry(asd_y, &notifier->waiting, list)
+		if (asd_equal(asd, asd_y))
 			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)
+		if (asd_equal(asd, sd->asd))
 			return true;
 	}
 
@@ -338,32 +357,29 @@ static bool __v4l2_async_notifier_fwnode_has_async_subdev(
 }
 
 /*
- * Find out whether an async sub-device was set up for an fwnode already or
+ * Find out whether an async sub-device was set up 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)
+static bool
+v4l2_async_notifier_has_async_subdev(struct v4l2_async_notifier *notifier,
+				     struct v4l2_async_subdev *asd,
+				     unsigned int this_index)
 {
 	unsigned int j;
 
 	lockdep_assert_held(&list_lock);
 
-	/* Check that an fwnode is not being added more than once. */
+	/* Check that an asd 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];
+		struct v4l2_async_subdev *asd_y = notifier->subdevs[j];
 
-		if (other_asd->match_type == V4L2_ASYNC_MATCH_FWNODE &&
-		    asd->match.fwnode ==
-		    other_asd->match.fwnode)
+		if (asd_equal(asd, asd_y))
 			return true;
 	}
 
-	/* Check than an fwnode did not exist in other notifiers. */
+	/* Check that an asd does not exist in other notifiers. */
 	list_for_each_entry(notifier, &notifier_list, list)
-		if (__v4l2_async_notifier_fwnode_has_async_subdev(
-			    notifier, fwnode))
+		if (__v4l2_async_notifier_has_async_subdev(notifier, asd))
 			return true;
 
 	return false;
@@ -392,12 +408,11 @@ 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, i)) {
+			if (v4l2_async_notifier_has_async_subdev(notifier,
+								 asd, i)) {
 				dev_err(dev,
-					"fwnode has already been registered or in notifier's subdev list\n");
+					"subdev descriptor already listed in this or other notifiers\n");
 				ret = -EEXIST;
 				goto err_unlock;
 			}
Signature · 1 line
2.17.1
#3 lore raw

PATCH v7 3/17 media: v4l2: async: Add v4l2_async_notifier_add_subdev

In reply to Steve Longerbeam

v4l2_async_notifier_add_subdev() adds an asd to the notifier. It checks that no other equivalent asd's have already been added to this notifier's asd list, or to other registered notifier's waiting or done lists, and increments num_subdevs.

v4l2_async_notifier_add_subdev() does not make use of the notifier subdevs array, otherwise it would have to re-allocate the array every time the function was called. In place of the subdevs array, the function adds the newly allocated asd to a new master asd_list. The function will return error with a WARN() if it is ever called with the subdevs array allocated.

Drivers are now required to call a v4l2_async_notifier_init(), before the first call to v4l2_async_notifier_add_subdev(), in order to initialize the asd_list.

In v4l2_async_notifier_has_async_subdev(), __v4l2_async_notifier_register(), and v4l2_async_notifier_cleanup(), maintain backward compatibility with the subdevs array, by alternatively operate on the subdevs array or a non-empty notifier->asd_list.

---
Changes since v6:
- add "already listed asd" message from __v4l2_async_notifier_register() to v4l2_async_notifier_asd_valid() as a debug message.
Changes since v5:
- export v4l2_async_notifier_init() which must be called by drivers. Suggested by Sakari Ailus.
Changes since v4:
- none
Changes since v3:
- init notifier lists after the sanity checks.
Changes since v2:
- add a NULL asd pointer check to v4l2_async_notifier_asd_valid(). Changes since v1:
- none

---
 drivers/media/v4l2-core/v4l2-async.c | 191 +++++++++++++++++++++------
 include/media/v4l2-async.h           |  34 ++++-
 2 files changed, 182 insertions(+), 43 deletions(-)
drivers/media/v4l2-core/v4l2-async.c +149 -42
index f09d354b96a0..7925875d09b7 100644
@@ -365,16 +365,26 @@ v4l2_async_notifier_has_async_subdev(struct v4l2_async_notifier *notifier,
 				     struct v4l2_async_subdev *asd,
 				     unsigned int this_index)
 {
+	struct v4l2_async_subdev *asd_y;
 	unsigned int j;
 
 	lockdep_assert_held(&list_lock);
 
 	/* Check that an asd is not being added more than once. */
-	for (j = 0; j < this_index; j++) {
-		struct v4l2_async_subdev *asd_y = notifier->subdevs[j];
-
-		if (asd_equal(asd, asd_y))
-			return true;
+	if (notifier->subdevs) {
+		for (j = 0; j < this_index; j++) {
+			asd_y = notifier->subdevs[j];
+			if (asd_equal(asd, asd_y))
+				return true;
+		}
+	} else {
+		j = 0;
+		list_for_each_entry(asd_y, &notifier->asd_list, asd_list) {
+			if (j++ >= this_index)
+				break;
+			if (asd_equal(asd, asd_y))
+				return true;
+		}
 	}
 
 	/* Check that an asd does not exist in other notifiers. */
@@ -385,10 +395,48 @@ v4l2_async_notifier_has_async_subdev(struct v4l2_async_notifier *notifier,
 	return false;
 }
 
-static int __v4l2_async_notifier_register(struct v4l2_async_notifier *notifier)
+static int v4l2_async_notifier_asd_valid(struct v4l2_async_notifier *notifier,
+					 struct v4l2_async_subdev *asd,
+					 unsigned int this_index)
 {
 	struct device *dev =
 		notifier->v4l2_dev ? notifier->v4l2_dev->dev : NULL;
+
+	if (!asd)
+		return -EINVAL;
+
+	switch (asd->match_type) {
+	case V4L2_ASYNC_MATCH_CUSTOM:
+	case V4L2_ASYNC_MATCH_DEVNAME:
+	case V4L2_ASYNC_MATCH_I2C:
+	case V4L2_ASYNC_MATCH_FWNODE:
+		if (v4l2_async_notifier_has_async_subdev(notifier, asd,
+							 this_index)) {
+			dev_dbg(dev, "subdev descriptor already listed in this or other notifiers\n");
+			return -EEXIST;
+		}
+		break;
+	default:
+		dev_err(dev, "Invalid match type %u on %p\n",
+			asd->match_type, asd);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+void v4l2_async_notifier_init(struct v4l2_async_notifier *notifier)
+{
+	mutex_lock(&list_lock);
+
+	INIT_LIST_HEAD(&notifier->asd_list);
+
+	mutex_unlock(&list_lock);
+}
+EXPORT_SYMBOL(v4l2_async_notifier_init);
+
+static int __v4l2_async_notifier_register(struct v4l2_async_notifier *notifier)
+{
 	struct v4l2_async_subdev *asd;
 	int ret;
 	int i;
@@ -401,29 +449,25 @@ static int __v4l2_async_notifier_register(struct v4l2_async_notifier *notifier)
 
 	mutex_lock(&list_lock);
 
-	for (i = 0; i < notifier->num_subdevs; i++) {
-		asd = notifier->subdevs[i];
+	if (notifier->subdevs) {
+		for (i = 0; i < notifier->num_subdevs; i++) {
+			asd = notifier->subdevs[i];
 
-		switch (asd->match_type) {
-		case V4L2_ASYNC_MATCH_CUSTOM:
-		case V4L2_ASYNC_MATCH_DEVNAME:
-		case V4L2_ASYNC_MATCH_I2C:
-		case V4L2_ASYNC_MATCH_FWNODE:
-			if (v4l2_async_notifier_has_async_subdev(notifier,
-								 asd, i)) {
-				dev_err(dev,
-					"subdev descriptor already listed in this or other notifiers\n");
-				ret = -EEXIST;
+			ret = v4l2_async_notifier_asd_valid(notifier, asd, i);
+			if (ret)
 				goto err_unlock;
-			}
-			break;
-		default:
-			dev_err(dev, "Invalid match type %u on %p\n",
-				asd->match_type, asd);
-			ret = -EINVAL;
-			goto err_unlock;
+
+			list_add_tail(&asd->list, &notifier->waiting);
+		}
+	} else {
+		i = 0;
+		list_for_each_entry(asd, &notifier->asd_list, asd_list) {
+			ret = v4l2_async_notifier_asd_valid(notifier, asd, i++);
+			if (ret)
+				goto err_unlock;
+
+			list_add_tail(&asd->list, &notifier->waiting);
 		}
-		list_add_tail(&asd->list, &notifier->waiting);
 	}
 
 	ret = v4l2_async_notifier_try_all_subdevs(notifier);
@@ -513,36 +557,99 @@ 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)
+static void __v4l2_async_notifier_cleanup(struct v4l2_async_notifier *notifier)
 {
+	struct v4l2_async_subdev *asd, *tmp;
 	unsigned int i;
 
-	if (!notifier || !notifier->max_subdevs)
+	if (!notifier)
 		return;
 
-	for (i = 0; i < notifier->num_subdevs; i++) {
-		struct v4l2_async_subdev *asd = notifier->subdevs[i];
+	if (notifier->subdevs) {
+		if (!notifier->max_subdevs)
+			return;
 
-		switch (asd->match_type) {
-		case V4L2_ASYNC_MATCH_FWNODE:
-			fwnode_handle_put(asd->match.fwnode);
-			break;
-		default:
-			WARN_ON_ONCE(true);
-			break;
+		for (i = 0; i < notifier->num_subdevs; i++) {
+			asd = notifier->subdevs[i];
+
+			switch (asd->match_type) {
+			case V4L2_ASYNC_MATCH_FWNODE:
+				fwnode_handle_put(asd->match.fwnode);
+				break;
+			default:
+				break;
+			}
+
+			kfree(asd);
 		}
 
-		kfree(asd);
+		notifier->max_subdevs = 0;
+		kvfree(notifier->subdevs);
+		notifier->subdevs = NULL;
+	} else {
+		list_for_each_entry_safe(asd, tmp,
+					 &notifier->asd_list, asd_list) {
+			switch (asd->match_type) {
+			case V4L2_ASYNC_MATCH_FWNODE:
+				fwnode_handle_put(asd->match.fwnode);
+				break;
+			default:
+				break;
+			}
+
+			list_del(&asd->asd_list);
+			kfree(asd);
+		}
 	}
 
-	notifier->max_subdevs = 0;
 	notifier->num_subdevs = 0;
+}
+
+void v4l2_async_notifier_cleanup(struct v4l2_async_notifier *notifier)
+{
+	mutex_lock(&list_lock);
+
+	__v4l2_async_notifier_cleanup(notifier);
 
-	kvfree(notifier->subdevs);
-	notifier->subdevs = NULL;
+	mutex_unlock(&list_lock);
 }
 EXPORT_SYMBOL_GPL(v4l2_async_notifier_cleanup);
 
+int v4l2_async_notifier_add_subdev(struct v4l2_async_notifier *notifier,
+				   struct v4l2_async_subdev *asd)
+{
+	int ret;
+
+	mutex_lock(&list_lock);
+
+	if (notifier->num_subdevs >= V4L2_MAX_SUBDEVS) {
+		ret = -EINVAL;
+		goto unlock;
+	}
+
+	/*
+	 * If caller uses this function, it cannot also allocate and
+	 * place asd's in the notifier->subdevs array.
+	 */
+	if (WARN_ON(notifier->subdevs)) {
+		ret = -EINVAL;
+		goto unlock;
+	}
+
+	ret = v4l2_async_notifier_asd_valid(notifier, asd,
+					    notifier->num_subdevs);
+	if (ret)
+		goto unlock;
+
+	list_add_tail(&asd->asd_list, &notifier->asd_list);
+	notifier->num_subdevs++;
+
+unlock:
+	mutex_unlock(&list_lock);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(v4l2_async_notifier_add_subdev);
+
 int v4l2_async_register_subdev(struct v4l2_subdev *sd)
 {
 	struct v4l2_async_notifier *subdev_notifier;
@@ -616,7 +723,7 @@ 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);
+	__v4l2_async_notifier_cleanup(sd->subdev_notifier);
 	kfree(sd->subdev_notifier);
 	sd->subdev_notifier = NULL;
 
include/media/v4l2-async.h +33 -1
index 1592d323c577..ab4d7acb7960 100644
@@ -73,6 +73,8 @@ enum v4l2_async_match_type {
  * @match.custom.priv:
  *		Driver-specific private struct with match parameters
  *		to be used if %V4L2_ASYNC_MATCH_CUSTOM.
+ * @asd_list:	used to add struct v4l2_async_subdev objects to the
+ *		master notifier @asd_list
  * @list:	used to link struct v4l2_async_subdev objects, waiting to be
  *		probed, to a notifier->waiting list
  *
@@ -98,6 +100,7 @@ struct v4l2_async_subdev {
 
 	/* v4l2-async core private: not to be used by drivers */
 	struct list_head list;
+	struct list_head asd_list;
 };
 
 /**
@@ -127,6 +130,7 @@ struct v4l2_async_notifier_operations {
  * @v4l2_dev:	v4l2_device of the root notifier, NULL otherwise
  * @sd:		sub-device that registered the notifier, NULL otherwise
  * @parent:	parent notifier
+ * @asd_list:	master list of struct v4l2_async_subdev, replaces @subdevs
  * @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
@@ -139,11 +143,37 @@ struct v4l2_async_notifier {
 	struct v4l2_device *v4l2_dev;
 	struct v4l2_subdev *sd;
 	struct v4l2_async_notifier *parent;
+	struct list_head asd_list;
 	struct list_head waiting;
 	struct list_head done;
 	struct list_head list;
 };
 
+/**
+ * v4l2_async_notifier_init - Initialize a notifier.
+ *
+ * @notifier: pointer to &struct v4l2_async_notifier
+ *
+ * This function initializes the notifier @asd_list. It must be called
+ * before the first call to @v4l2_async_notifier_add_subdev.
+ */
+void v4l2_async_notifier_init(struct v4l2_async_notifier *notifier);
+
+/**
+ * v4l2_async_notifier_add_subdev - Add an async subdev to the
+ *				notifier's master asd list.
+ *
+ * @notifier: pointer to &struct v4l2_async_notifier
+ * @asd: pointer to &struct v4l2_async_subdev
+ *
+ * This can be used before registering a notifier to add an
+ * asd to the notifiers @asd_list. If the caller uses this
+ * method to compose an asd list, it must never allocate
+ * or place asd's in the @subdevs array.
+ */
+int v4l2_async_notifier_add_subdev(struct v4l2_async_notifier *notifier,
+				   struct v4l2_async_subdev *asd);
+
 /**
  * v4l2_async_notifier_register - registers a subdevice asynchronous notifier
  *
@@ -177,7 +207,9 @@ 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 or
+ * notifier after calling
+ * @v4l2_async_notifier_add_subdev,
+ * @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
Signature · 1 line
2.17.1
#4 lore raw

PATCH v7 4/17 media: v4l2: async: Add convenience functions to allocate and add asd's

In reply to Steve Longerbeam

Add these convenience functions, which allocate an asd of match type fwnode, i2c, or device-name, of size asd_struct_size, and then adds them to the notifier asd_list.

---
 drivers/media/v4l2-core/v4l2-async.c | 76 ++++++++++++++++++++++++++++
 include/media/v4l2-async.h           | 62 +++++++++++++++++++++++
 2 files changed, 138 insertions(+)
drivers/media/v4l2-core/v4l2-async.c +76 -0
index 7925875d09b7..196573f4ec48 100644
@@ -650,6 +650,82 @@ int v4l2_async_notifier_add_subdev(struct v4l2_async_notifier *notifier,
 }
 EXPORT_SYMBOL_GPL(v4l2_async_notifier_add_subdev);
 
+struct v4l2_async_subdev *
+v4l2_async_notifier_add_fwnode_subdev(struct v4l2_async_notifier *notifier,
+				      struct fwnode_handle *fwnode,
+				      unsigned int asd_struct_size)
+{
+	struct v4l2_async_subdev *asd;
+	int ret;
+
+	asd = kzalloc(asd_struct_size, GFP_KERNEL);
+	if (!asd)
+		return ERR_PTR(-ENOMEM);
+
+	asd->match_type = V4L2_ASYNC_MATCH_FWNODE;
+	asd->match.fwnode = fwnode;
+
+	ret = v4l2_async_notifier_add_subdev(notifier, asd);
+	if (ret) {
+		kfree(asd);
+		return ERR_PTR(ret);
+	}
+
+	return asd;
+}
+EXPORT_SYMBOL_GPL(v4l2_async_notifier_add_fwnode_subdev);
+
+struct v4l2_async_subdev *
+v4l2_async_notifier_add_i2c_subdev(struct v4l2_async_notifier *notifier,
+				   int adapter_id, unsigned short address,
+				   unsigned int asd_struct_size)
+{
+	struct v4l2_async_subdev *asd;
+	int ret;
+
+	asd = kzalloc(asd_struct_size, GFP_KERNEL);
+	if (!asd)
+		return ERR_PTR(-ENOMEM);
+
+	asd->match_type = V4L2_ASYNC_MATCH_I2C;
+	asd->match.i2c.adapter_id = adapter_id;
+	asd->match.i2c.address = address;
+
+	ret = v4l2_async_notifier_add_subdev(notifier, asd);
+	if (ret) {
+		kfree(asd);
+		return ERR_PTR(ret);
+	}
+
+	return asd;
+}
+EXPORT_SYMBOL_GPL(v4l2_async_notifier_add_i2c_subdev);
+
+struct v4l2_async_subdev *
+v4l2_async_notifier_add_devname_subdev(struct v4l2_async_notifier *notifier,
+				       const char *device_name,
+				       unsigned int asd_struct_size)
+{
+	struct v4l2_async_subdev *asd;
+	int ret;
+
+	asd = kzalloc(asd_struct_size, GFP_KERNEL);
+	if (!asd)
+		return ERR_PTR(-ENOMEM);
+
+	asd->match_type = V4L2_ASYNC_MATCH_DEVNAME;
+	asd->match.device_name = device_name;
+
+	ret = v4l2_async_notifier_add_subdev(notifier, asd);
+	if (ret) {
+		kfree(asd);
+		return ERR_PTR(ret);
+	}
+
+	return asd;
+}
+EXPORT_SYMBOL_GPL(v4l2_async_notifier_add_devname_subdev);
+
 int v4l2_async_register_subdev(struct v4l2_subdev *sd)
 {
 	struct v4l2_async_notifier *subdev_notifier;
include/media/v4l2-async.h +62 -0

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Signature · 1 line
2.17.1