Hi Laurent,
On Tue, Aug 29, 2017 at 05:02:54PM +0300, Laurent Pinchart wrote:
> Hi Sakari,
>
> Thank you for the patch.
Thanks for the review!
>
> On Tuesday, 29 August 2017 14:03:12 EEST 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.
> >
> > Signed-off-by: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
> > ---
> > 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 | 132
> > ++++++++++++++++++++++++++++++++++ include/media/v4l2-async.h |
> > 20 +++++-
> > include/media/v4l2-fwnode.h | 39 ++++++++++
> > 6 files changed, 242 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..c490acf5ae82
> > 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;
> > +
> > + if (!notifier->max_subdevs)
> > + return;
> > +
> > + for (i = 0; i < notifier->num_subdevs; i++)
> > + kfree(notifier->subdevs[i]);
> > +
> > + kvfree(notifier->subdevs);
> > + notifier->max_subdevs = 0;
> > +}
> > +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..39a587c6992a
> > 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 +315,136 @@ void v4l2_fwnode_put_link(struct v4l2_fwnode_link
> > *link) }
> > EXPORT_SYMBOL_GPL(v4l2_fwnode_put_link);
> >
> > +static int notifier_realloc(struct v4l2_async_notifier *notifier,
> > + unsigned int max_subdevs)
>
> I'd prefix static functions with v4l2_async_ to avoid namespace clashes.
I can add that.
>
> > +{
> > + struct v4l2_async_subdev **subdevs;
> > + unsigned int i;
> > +
> > + if (max_subdevs <= notifier->max_subdevs)
> > + return 0;
> > +
> > + subdevs = kvmalloc_array(
> > + max_subdevs, sizeof(*notifier->subdevs),
> > + GFP_KERNEL | __GFP_ZERO);
>
> Should it be mentioned in the documentation that the address of the subdevs
> array will change during parsing and should not be stored by drivers ? It
> might be overkill.
It won't hurt. I'll add that.
>
> > + if (!subdevs)
> > + return -ENOMEM;
> > +
> > + if (notifier->subdevs) {
> > + for (i = 0; i < notifier->num_subdevs; i++)
> > + subdevs[i] = notifier->subdevs[i];
>
> To answer your previous question, yes, I would find
>
> memcpy(subdevs, notifier->subdevs, sizeof(*subdevs) * num_subdevs);
>
> easier to read :-)
I don't agree but I don't have a strong opinion about this, I can change
it.
>
> > + kvfree(notifier->subdevs);
> > + }
> > +
> > + notifier->subdevs = subdevs;
> > + notifier->max_subdevs = max_subdevs;
> > +
> > + return 0;
> > +}
> > +
> > +static int 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. */
>
> You don't ignore them anymore, the comment should be updated.
Hmm. I actually intended to do something else about this. :-) As there's a
single error code, handling that would need to be done a little bit
differently right now.
I'd print a warning and proceed. What do you think?
Even if there's a bad DT endpoint, that shouldn't prevent the rest from
working, right?
>
> > + 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);
> > + 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;
> > + int ret;
> > +
> > + if (asd_struct_size < sizeof(struct v4l2_async_subdev) ||
> > + notifier->v4l2_dev)
> > + return -EINVAL;
> > +
> > + 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 = notifier_realloc(notifier, max_subdevs);
> > + if (ret)
> > + return ret;
> > +
> > + 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 = 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.ailus@xxxxxxxxxxxxxxx>");
> > MODULE_AUTHOR("Sylwester Nawrocki <s.nawrocki@xxxxxxxxxxx>");
> > diff --git a/include/media/v4l2-async.h b/include/media/v4l2-async.h
> > index c69d8c8a66d0..4a44ab47ab04 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
> > @@ -78,7 +77,8 @@ 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
> > + * @max_subdevs: number of subdevices allocated in 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 +90,7 @@ 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 +122,21 @@ 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: pointer to &struct v4l2_async_notifier
>
> That's quite obvious given the type of the argument. It would be much more
> useful to tell which notifier pointer this function expects (although in this
> case it should be obvious too): "(pointer to )?the notifier whose resources
> will be released".
This fully matches to the documentation elsewhere in the same file. :-)
I'll replace the text with yours.
>
> > + *
> > + * Release memory resources related to a notifier, including the async
> > + * 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.
>
> Zeroing the memory is pretty much a requirement, as
> v4l2_async_notifier_parse_fwnode_endpoints() won't operate correctly if memory
> contains random data anyway. Maybe we should introduce
> v4l2_async_notifier_init() and make v4l2_async_notifier_release() mandatory,
> but that's out of scope for this patch.
Notifiers are typically allocated as part of a driver specific struct which
is zeroed by the driver.
Registering the notifier won't work either if the rest of the struct wasn't
zeroed.
>
> > + */
> > +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..46521e8c8872 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 +203,41 @@ 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: @struct device pointer
>
> Similarly to my previous comment (and my comments to v3), you should tell
> which device the function expects.
Will fix for the next version.
>
> > + * @notifier: pointer to &struct v4l2_async_notifier
> > + * @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.
>
> Should this be documented in the kerneldoc of the v4l2_async_subdev structure
> ?
Yes, I'll add that. It won't hurt to make it a requirement even if the
helper functions weren't used.
>
> > + * @parse_single: driver's callback function called on each V4L2 fwnode
> > endpoint
> > + *
> > + * Allocate async sub-device array and sub-devices for each fwnode
> > endpoint,
> > + * parse the related fwnode endpoints and finally call driver's callback
> > + * function to that V4L2 fwnode endpoint.
>
> I'd document this from the notifier point of view.
>
> "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."
Works for me.
>
> > + * The function may not be called on a registered notifier.
>
> You should mention that the function may be called multiple times on an
> unregistered notifier.
There's no point in calling it more than once as the endpoints wouldn't end
up being different from the previous time. Actually it'd make sense to
document this.
>
> "The function can be called multiple times to populate the same notifier from
> endpoints of different @dev devices before registering the notifier. It can't
> be called anymore once the notifier has been registered."
I don't think there's really a use case for calling this for more than one
device, is there?
>
> > + *
> > + * Once the user has called this function, the resources released by it
> > need to
> > + * be released by callin v4l2_async_notifier_release after the notifier has
> > been
> > + * unregistered and the sub-devices are no longer in use.
>
> "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."
Agreed.
>
> > + *
> > + * A driver supporting fwnode (currently Devicetree and ACPI) should call
> > this
> > + * function as part of its probe function before it registers the notifier.
> > + *
> > + * 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 */
>
>
--
Kind regards,
Sakari Ailus
e-mail: sakari.ailus@xxxxxx
