Hi Sakari, On 20-01-07 15:49, Sakari Ailus wrote: > Hi Marco, > > On Tue, Dec 10, 2019 at 10:50:03AM +0100, Marco Felsch wrote: > > Hi Sakari, > > > > On 19-11-27 14:24, Sakari Ailus wrote: > > > Hi Marco, > > > > > > On Wed, Nov 27, 2019 at 09:26:16AM +0100, Marco Felsch wrote: > > > > Hi Sakari, > > > > > > > > this is a gentle ping and I've added a comment inline. > > > > > > > > On 19-11-19 12:15, Marco Felsch wrote: > > > > > Hi Sakari, > > > > > > > > > > many thanks for the review :) > > > > > > > > > > On 19-11-16 01:06, Sakari Ailus wrote: > > > > > > Hi Marco, > > > > > > > > > > > > On Fri, Nov 08, 2019 at 09:58:52AM +0100, Marco Felsch wrote: > > > > > > > Hi Sakari, > > > > > > > > > > > > > > sorry for my delay now ^^ > > > > > > > > > > > > > > On 19-10-24 15:02, Sakari Ailus wrote: > > > > > > > > Hi Marco, > > > > > > > > > > > > > > > > On Wed, Oct 23, 2019 at 02:21:57PM +0200, Marco Felsch wrote: > > > > > > > > > Hi Sakari, > > > > > > > > > > > > > > > > > > On 19-10-23 13:57, Sakari Ailus wrote: > > > > > > > > > > Hi Marco, > > > > > > > > > > > > > > > > > > > > Apologies for the delay. > > > > > > > > > > > > > > > > > > No problem. > > > > > > > > > > > > > > > > > > > On Wed, Oct 02, 2019 at 10:07:35AM +0200, Marco Felsch wrote: > > > > > > > > > > > Hi Sakari, > > > > > > > > > > > > > > > > > > > > > > On 19-10-02 10:03, Sakari Ailus wrote: > > > > > > > > > > > > Hi Marco, > > > > > > > > > > > > > > > > > > > > > > > > On Fri, Aug 30, 2019 at 12:16:35PM +0200, Marco Felsch wrote: > > > > > > > > > > > > > The patch adds the initial connector parsing code, so we can move from a > > > > > > > > > > > > > driver specific parsing code to a generic one. Currently only the > > > > > > > > > > > > > generic fields and the analog-connector specific fields are parsed. Parsing > > > > > > > > > > > > > the other connector specific fields can be added by a simple callbacks. > > > > > > > > > > > > > > > > > > > > > > > > > > Signed-off-by: Marco Felsch <m.felsch@xxxxxxxxxxxxxx> > > > > > > > > > > > > > --- > > > > > > > > > > > > > [1] https://patchwork.kernel.org/cover/10794703/ > > > > > > > > > > > > > > > > > > > > > > > > > > v10: > > > > > > > > > > > > > - drop V4L2_CONN_HDMI support > > > > > > > > > > > > > - adapt pr_err msg to reflect new state (-> connector is unkown) > > > > > > > > > > > > > > > > > > > > > > > > > > v9: > > > > > > > > > > > > > - Fix leading semicolon found by kbuild semicolon.cocci > > > > > > > > > > > > > > > > > > > > > > > > > > v8: > > > > > > > > > > > > > - V4L2_CON_* -> V4L2_CONN_* > > > > > > > > > > > > > - tvnorms -> sdtv-standards > > > > > > > > > > > > > - adapt to new v4l2_fwnode_connector_analog member > > > > > > > > > > > > > - return error in case of V4L2_CONN_HDMI > > > > > > > > > > > > > > > > > > > > > > > > > > v7: > > > > > > > > > > > > > @Jacopo: I dropped your r b tag becuase of the amount of changes I > > > > > > > > > > > > > made.. > > > > > > > > > > > > > > > > > > > > > > > > > > - drop unnecessary comments > > > > > > > > > > > > > - fix commet style > > > > > > > > > > > > > - s/v4l2_fwnode_connector_conv.name/v4l2_fwnode_connector_conv.compatible/ > > > > > > > > > > > > > - make label size variable and drop V4L2_CONNECTOR_MAX_LABEL usage > > > > > > > > > > > > > - do not assign a default label in case of no label was specified > > > > > > > > > > > > > - remove useless /* fall through */ comments > > > > > > > > > > > > > - add support for N connector links > > > > > > > > > > > > > - rename local variables to be more meaningful > > > > > > > > > > > > > - adjust kernedoc > > > > > > > > > > > > > - add v4l2_fwnode_connector_free() > > > > > > > > > > > > > - improve error handling (use different error values) > > > > > > > > > > > > > - make use of pr_warn_once() > > > > > > > > > > > > > > > > > > > > > > > > > > v6: > > > > > > > > > > > > > - use unsigned count var > > > > > > > > > > > > > - fix comment and style issues > > > > > > > > > > > > > - place '/* fall through */' to correct places > > > > > > > > > > > > > - fix error handling and cleanup by releasing fwnode > > > > > > > > > > > > > - drop vga and dvi parsing support as those connectors are rarely used > > > > > > > > > > > > > these days > > > > > > > > > > > > > > > > > > > > > > > > > > v5: > > > > > > > > > > > > > - s/strlcpy/strscpy/ > > > > > > > > > > > > > > > > > > > > > > > > > > v2-v4: > > > > > > > > > > > > > - nothing since the patch was squashed from series [1] into this > > > > > > > > > > > > > series. > > > > > > > > > > > > > > > > > > > > > > > > > > drivers/media/v4l2-core/v4l2-fwnode.c | 129 ++++++++++++++++++++++++++ > > > > > > > > > > > > > include/media/v4l2-fwnode.h | 38 ++++++++ > > > > > > > > > > > > > 2 files changed, 167 insertions(+) > > > > > > > > > > > > > > > > > > > > > > > > > > diff --git a/drivers/media/v4l2-core/v4l2-fwnode.c b/drivers/media/v4l2-core/v4l2-fwnode.c > > > > > > > > > > > > > index 3bd1888787eb..0bfa7cbf78df 100644 > > > > > > > > > > > > > --- a/drivers/media/v4l2-core/v4l2-fwnode.c > > > > > > > > > > > > > +++ b/drivers/media/v4l2-core/v4l2-fwnode.c > > > > > > > > > > > > > @@ -595,6 +595,135 @@ void v4l2_fwnode_put_link(struct v4l2_fwnode_link *link) > > > > > > > > > > > > > } > > > > > > > > > > > > > EXPORT_SYMBOL_GPL(v4l2_fwnode_put_link); > > > > > > > > > > > > > > > > > > > > > > > > > > +static const struct v4l2_fwnode_connector_conv { > > > > > > > > > > > > > + enum v4l2_connector_type type; > > > > > > > > > > > > > + const char *compatible; > > > > > > > > > > > > > +} connectors[] = { > > > > > > > > > > > > > + { > > > > > > > > > > > > > + .type = V4L2_CONN_COMPOSITE, > > > > > > > > > > > > > + .compatible = "composite-video-connector", > > > > > > > > > > > > > + }, { > > > > > > > > > > > > > + .type = V4L2_CONN_SVIDEO, > > > > > > > > > > > > > + .compatible = "svideo-connector", > > > > > > > > > > > > > + }, > > > > > > > > > > > > > +}; > > > > > > > > > > > > > + > > > > > > > > > > > > > +static enum v4l2_connector_type > > > > > > > > > > > > > +v4l2_fwnode_string_to_connector_type(const char *con_str) > > > > > > > > > > > > > +{ > > > > > > > > > > > > > + unsigned int i; > > > > > > > > > > > > > + > > > > > > > > > > > > > + for (i = 0; i < ARRAY_SIZE(connectors); i++) > > > > > > > > > > > > > + if (!strcmp(con_str, connectors[i].compatible)) > > > > > > > > > > > > > + return connectors[i].type; > > > > > > > > > > > > > + > > > > > > > > > > > > > + return V4L2_CONN_UNKNOWN; > > > > > > > > > > > > > +} > > > > > > > > > > > > > + > > > > > > > > > > > > > +static int > > > > > > > > > > > > > +v4l2_fwnode_connector_parse_analog(struct fwnode_handle *fwnode, > > > > > > > > > > > > > + struct v4l2_fwnode_connector *vc) > > > > > > > > > > > > > +{ > > > > > > > > > > > > > + u32 stds; > > > > > > > > > > > > > + int ret; > > > > > > > > > > > > > + > > > > > > > > > > > > > + ret = fwnode_property_read_u32(fwnode, "sdtv-standards", &stds); > > > > > > > > > > > > > + > > > > > > > > > > > > > + /* The property is optional. */ > > > > > > > > > > > > > + vc->connector.analog.sdtv_stds = ret ? V4L2_STD_ALL : stds; > > > > > > > > > > > > > + > > > > > > > > > > > > > + return 0; > > > > > > > > > > > > > +} > > > > > > > > > > > > > + > > > > > > > > > > > > > +void v4l2_fwnode_connector_free(struct v4l2_fwnode_connector *connector) > > > > > > > > > > > > > +{ > > > > > > > > > > > > > + unsigned int i; > > > > > > > > > > > > > + > > > > > > > > > > > > > + if (IS_ERR_OR_NULL(connector)) > > > > > > > > > > > > > + return; > > > > > > > > > > > > > + > > > > > > > > > > > > > + for (i = 0; i < connector->nr_of_links; i++) > > > > > > > > > > > > > + v4l2_fwnode_put_link(&connector->links[i]); > > > > > > > > > > > > > + kfree(connector->links); > > > > > > > > > > > > > > > > > > > > > > > > Please assign connector->links NULL here, and nr_of_links to zero. > > > > > > > > > > > > > > > > > > > > > > Okay, I can do that. > > > > > > > > > > > > > > > > > > > > > > > > +} > > > > > > > > > > > > > +EXPORT_SYMBOL_GPL(v4l2_fwnode_connector_free); > > > > > > > > > > > > > + > > > > > > > > > > > > > +int v4l2_fwnode_connector_alloc_parse(struct fwnode_handle *fwnode, > > > > > > > > > > > > > + struct v4l2_fwnode_connector *connector) > > > > > > > > > > > > > +{ > > > > > > > > > > > > > + struct fwnode_handle *remote_pp, *remote_ep; > > > > > > > > > > > > > + const char *type_name; > > > > > > > > > > > > > + unsigned int i = 0, ep_num = 0; > > > > > > > > > > > > > + int err; > > > > > > > > > > > > > + > > > > > > > > > > > > > + memset(connector, 0, sizeof(*connector)); > > > > > > > > > > > > > + > > > > > > > > > > > > > + remote_pp = fwnode_graph_get_remote_port_parent(fwnode); > > > > > > > > > > > > > > > > > > > > > > > > How do you know a remote endpoint is a connector, and not another device's > > > > > > > > > > > > endpoint? > > > > > > > > > > > > > > > > > > > > > > Well, I think that the caller won't use this function if it isn't a > > > > > > > > > > > connector. If it helps I can check if the compatible of the remote ends > > > > > > > > > > > with "-connector". > > > > > > > > > > > > > > > > > > > > The function is called by a driver. A driver shouldn't know what's at the > > > > > > > > > > other end of the graph arc; the information should come from the firmware > > > > > > > > > > instead. > > > > > > > > > > > > > > > > > > > > On some board there could be another device where you have a connector now. > > > > > > > > > > > > > > > > > > > > As the connector has its own compatible string, there could be a connector > > > > > > > > > > driver to tell this is actually a connector, even if there's nothing to > > > > > > > > > > control. It'd be a very tiny driver. > > > > > > > > > > > > > > > > > > Yes I know a connector driver would be the best. This also have the > > > > > > > > > advantage to do drop the connector handling in each subdev driver.. But > > > > > > > > > unfortunately I haven't the time yet. Would it be okay for you too check > > > > > > > > > that the remote is a connector and if not to exit? > > > > > > > > > > > > > > > > The current design is also problematic in the sense that it parses remote DT > > > > > > > > graph endpoints (as well as device nodes) that are not under the device's > > > > > > > > own scope. > > > > > > > > > > > > > > You are right that is not good. Would it be okay with you to parse only > > > > > > > the local node so the caller must pass the connector node? > > > > > > > > > > > > > > > I wonder what kind of changes would that require, and how much more > > > > > > > > difficult would the changes be to implement later on if a number of drivers > > > > > > > > uses the newly added APIs. > > > > > > > > > > > > > > > > v4l2_fwnode_parse_endpoint() should be considered as well. This is the > > > > > > > > current API to parse endpoints. Could connectors be meaningfully parsed > > > > > > > > within v4l2_fwnode_parse_endpoint()? > > > > > > > > > > > > > > I think v4l2_fwnode_endpoint_parse() isn't the correct place. Of course > > > > > > > it is a endpoint but I don't think that a connector should be placed > > > > > > > there. Currently the endpoint is mostly used to describe the connection > > > > > > > between the isp and a sensor. I think we shouldn't add something > > > > > > > unrelated just because it's an fw-endpoint. The connector just describes > > > > > > > who users can interact with the device. A connector isn't connected to a > > > > > > > chip using mipi or something else. > > > > > > > > > > > > If the endpoints pointing to a connector are not parsed by > > > > > > v4l2_fwnode_endpoint_parse(), then it means that they're parsed somewhere > > > > > > else, and that's something the caller needs to know. The fact that there is > > > > > > a connector, is only apparent from the compatible string of the remote > > > > > > device. That's simply not something for the caller to figure out. > > > > > > > > > > That is a goot point, I got that. > > > > > > > > > > > Endpoints in general refer to other devices' connection points. It doesn't > > > > > > matter what kind of a device it is, they should be treated the same way. > > > > > > > > > > > > I'm still not proposing to mangle connectors with the bus properties. Still, > > > > > > the two are mostly exclusive: if there's a connector, then any properties of > > > > > > the signal likely have nothing to do what was described in the firmware. > > > > > > > > > > > > How about adding an fwnode API function called e.g.g > > > > > > v4l2_fwnode_is_connector(), to tell whether a given local endpoint is > > > > > > connected to a remote which is a connector? That, I think, would be > > > > > > sufficient to make the connectors vs. wired busses easy for drivers to work > > > > > > with. > > > > > > > > > > A v4l2_fwnode_is_connector() function is nice. Just to got you right, > > > > > you want something like: > > > > > > > > > > v4l2_fwnode_endpoint_alloc_parse() > > > > > { > > > > > int rval; > > > > > > > > > > if (v4l2_fwnode_is_connector()) > > > > > return v4l2_fwnode_connector_alloc_parse(); > > > > > > > > > > rval = __v4l2_fwnode_endpoint_parse(fwnode, vep); > > > > > if (rval < 0) > > > > > return rval; > > > > > > > > > > ... > > > > > } > > > > > > > > > > If I got that right we need to squash the 'struct v4l2_fwnode_connector' > > > > > into the 'struct v4l2_fwnode_endpoint' or we need to accept both structs. > > > > > The first attempt can be error prone if a caller access invalid data. > > > > > What do you think? > > > > > > > > After my short excursion to the drm subsystem I noticed such a function: > > > > drm_of_find_panel_or_bridge(). Basically the function fills a bridge or > > > > panel struct and the driver need to check if there was a panel or a > > > > bridge. It seems that we can use exactly the same logic for our > > > > use-case. > > > > > > We could. Then the bus_type field would likely need to be used for the > > > connector types as well. The field would seem to deserve a rename as a > > > result though. > > > > I don't think that we should squash both struct. Should we go the > > current way with just an additional v4l2_fwnode_is_connector() helper? > > So the driver knows which parse helper should be called? > > Thanks for the ping. ;) > I'm in favour of having such a helper, that's enough for drivers not having > to care too much about it. Connectors generally are somewhat different from > the rest of the busses (where the framework parses their properties) rather > than just the types of connectors being used. Okay, so just to get you right and summarise the discussion: * We have different helpers for parsing the endpoint (busses) and connectors. * Connectors are using seperate type: 'struct v4l2_fwnode_connector' * We have a helper to differentiate between connectors and other endpoints. Drivers can use this helper to check which helper should be called. Regards, Marco > -- > Regards, > > Sakari Ailus
