Hi Sakari,
On 30/08/17 14:45, Sakari Ailus wrote:
> The current practice is that drivers iterate over their endpoints and
> parse each endpoint separately. This is very similar in a number of
> drivers, implement a generic function for the job. Driver specific matters
> can be taken into account in the driver specific callback.
>
> Convert the omap3isp as an example.
It would be much easier to review if the omap3isp conversion was done in a
separate patch. Ditto for the rcar conversion, and I prefer to have both
at the end of the patch series, after the core code patches.
>
> Signed-off-by: Sakari Ailus <sakari.ai...@linux.intel.com>
> ---
> since v6:
>
> - Set notifier->subdevs NULL and notifier->num_subdevs 0 in
> v4l2_async_notifier_release().
>
> drivers/media/platform/omap3isp/isp.c | 115 ++++++++++-------------------
> drivers/media/platform/omap3isp/isp.h | 5 +-
> drivers/media/v4l2-core/v4l2-async.c | 16 +++++
> drivers/media/v4l2-core/v4l2-fwnode.c | 131
> ++++++++++++++++++++++++++++++++++
> include/media/v4l2-async.h | 24 ++++++-
> include/media/v4l2-fwnode.h | 48 +++++++++++++
> 6 files changed, 254 insertions(+), 85 deletions(-)
>
> diff --git a/drivers/media/platform/omap3isp/isp.c
> b/drivers/media/platform/omap3isp/isp.c
> index 1a428fe9f070..a546cf774d40 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_release(&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,
> @@ -2256,7 +2210,9 @@ static int isp_probe(struct platform_device *pdev)
> if (ret)
> return ret;
>
> - ret = isp_fwnodes_parse(&pdev->dev, &isp->notifier);
> + ret = v4l2_async_notifier_parse_fwnode_endpoints(
> + &pdev->dev, &isp->notifier, sizeof(struct isp_async_subdev),
> + isp_fwnode_parse);
> if (ret < 0)
> return ret;
>
> @@ -2407,6 +2363,7 @@ static int isp_probe(struct platform_device *pdev)
> __omap3isp_put(isp, false);
> error:
> mutex_destroy(&isp->isp_mutex);
> + v4l2_async_notifier_release(&isp->notifier);
>
> 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) \
> diff --git a/drivers/media/v4l2-core/v4l2-async.c
> b/drivers/media/v4l2-core/v4l2-async.c
> index 851f128eba22..6740a241d4a1 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)
> @@ -278,6 +279,21 @@ void v4l2_async_notifier_unregister(struct
> v4l2_async_notifier *notifier)
> }
> EXPORT_SYMBOL(v4l2_async_notifier_unregister);
>
> +void v4l2_async_notifier_release(struct v4l2_async_notifier *notifier)
> +{
> + unsigned int i;
> +
> + for (i = 0; i < notifier->num_subdevs; i++)
> + kfree(notifier->subdevs[i]);
> +
> + notifier->max_subdevs = 0;
> + notifier->num_subdevs = 0;
> +
> + kvfree(notifier->subdevs);
> + notifier->subdevs = NULL;
> +}
> +EXPORT_SYMBOL_GPL(v4l2_async_notifier_release);
> +
> 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 706f9e7b90f1..2496d76eef4b 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 {
> @@ -313,6 +315,135 @@ 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;
Should probably be a WARN_ON. Or add a comment saying that this should
never happen.
> +
> + 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_single)(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.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;
> + }
> +
> + /* Ignore endpoints the parsing of which failed. */
> + 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_single(dev, vep, asd);
> + v4l2_fwnode_endpoint_free(vep);
> + if (ret) {
> + dev_warn(dev, "driver could not parse endpoint (%d)\n", ret);
> + goto out_err;
> + }
> +
> + asd->match_type = V4L2_ASYNC_MATCH_FWNODE;
> + notifier->subdevs[notifier->num_subdevs] = asd;
> + notifier->num_subdevs++;
> +
> + return 0;
> +
> +out_err:
> + fwnode_handle_put(asd->match.fwnode.fwnode);
Just checking: the fwnode_handle_put argument can safely be NULL?
> + kfree(asd);
> +
> + return ret;
> +}
> +
> +int v4l2_async_notifier_parse_fwnode_endpoints(
> + struct device *dev, struct v4l2_async_notifier *notifier,
> + size_t asd_struct_size,
> + int (*parse_single)(struct device *dev,
> + struct v4l2_fwnode_endpoint *vep,
> + struct v4l2_async_subdev *asd))
> +{
> + struct fwnode_handle *fwnode = NULL;
> + unsigned int max_subdevs = notifier->max_subdevs;
I thought the notifier was supposed to be zeroed?
> + int ret;
> +
> + if (asd_struct_size < sizeof(struct v4l2_async_subdev) ||
> + notifier->v4l2_dev)
This could use a comment why you check for notifier->v4l2_dev. That's not
obvious.
> + return -EINVAL;
Since we have the requirement that the notifier should be zeroed,
why not do that here?
> +
> + for (fwnode = NULL; (fwnode = fwnode_graph_get_next_endpoint(
> + dev_fwnode(dev), fwnode)); )
> + if (fwnode_device_is_available(
> + fwnode_graph_get_port_parent(fwnode)))
> + 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;
I think this is confusing. There is nothing to realloc here. Only in the
next patch (5/5) do you add support for recursively walking the graph and
adding more subdevs.
I would just call kvmalloc_array here.
> +
> + for (fwnode = NULL; (fwnode = fwnode_graph_get_next_endpoint(
> + dev_fwnode(dev), fwnode)); ) {
> + if (!fwnode_device_is_available(
> + fwnode_graph_get_port_parent(fwnode)))
> + continue;
> +
> + if (WARN_ON(notifier->num_subdevs >= notifier->max_subdevs))
> + break;
> +
> + ret = v4l2_async_notifier_fwnode_parse_endpoint(
> + dev, notifier, fwnode, asd_struct_size, parse_single);
> + if (ret < 0)
> + break;
> + }
> +
> + fwnode_handle_put(fwnode);
> +
> + return ret;
> +}
> +EXPORT_SYMBOL_GPL(v4l2_async_notifier_parse_fwnode_endpoints);
> +
> MODULE_LICENSE("GPL");
> MODULE_AUTHOR("Sakari Ailus <sakari.ai...@linux.intel.com>");
> MODULE_AUTHOR("Sylwester Nawrocki <s.nawro...@samsung.com>");
> diff --git a/include/media/v4l2-async.h b/include/media/v4l2-async.h
> index c69d8c8a66d0..cf13c7311a1c 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 the struct is used as the first member of a driver specific
Just replace "the first member" by "part"...
> + * struct, the driver specific struct shall contain the @struct
> + * v4l2_async_subdev as its first member.
...since you mention in the second part that it has to be the first member.
No need to mention that twice.
> */
> 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 subdevs array
in the
> + * @max_subdevs: number of subdevices allocated in subdevs array
in the
> * @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_release - release notifier resources
> + * @notifier: the notifier the resources of which are to be released
Just say: @notifier: pointer to &struct v4l2_async_notifier
> + *
> + * Release memory resources related to a notifier, including the async
s/a/the/
> + * sub-devices allocated for the purposes of the notifier. The user is
> + * responsible for releasing the notifier's resources after calling
> + * @v4l2_async_notifier_parse_fwnode_endpoints.
> + *
> + * There is no harm from calling v4l2_async_notifier_release in other
> + * cases as long as its memory has been zeroed after it has been
> + * allocated.
> + */
> +void v4l2_async_notifier_release(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 68eb22ba571b..d063ab4ff67b 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
>
> @@ -201,4 +203,50 @@ int v4l2_fwnode_parse_link(struct fwnode_handle *fwnode,
> */
> 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_single: driver's callback function called on each V4L2 fwnode
> endpoint
> + *
> + * Parse the fwnode endpoints of the @dev device and populate the async sub-
> + * devices array of the notifier. The @parse_endpoint callback function is
parse_endpoint -> parse_single
(Actually, I like the name parse_endpoint better)
> + * 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. When using this function, the user may not access
> the
> + * notifier's subdevs array nor change notifier's num_subdevs field, these
> are
> + * reserved for the framework's internal use only.
Ditto for the max_subdevs field, I think.
> + *
> + * The @struct v4l2_fwnode_endpoint passed to the callback function
> + * @parse_single 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_release() after it has been unregistered and the async
> + * sub-devices are no longer in use.
> + *
> + * 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_single
> + */
> +int v4l2_async_notifier_parse_fwnode_endpoints(
> + struct device *dev, struct v4l2_async_notifier *notifier,
> + size_t asd_struct_size,
> + int (*parse_single)(struct device *dev,
> + struct v4l2_fwnode_endpoint *vep,
> + struct v4l2_async_subdev *asd));
> +
> #endif /* _V4L2_FWNODE_H */
>
Regards,
Hans
