On Wed, Nov 30, 2016 at 04:14:11PM -0800, Kevin Hilman wrote:
> Sakari Ailus <sakari.ailus@xxxxxx> writes:
>
> > Hi Kevin,
> >
> > On Wed, Nov 23, 2016 at 03:25:32PM -0800, Kevin Hilman wrote:
> >> Hi Sakari,
> >>
> >> Sakari Ailus <sakari.ailus@xxxxxx> writes:
> >>
> >> > On Tue, Nov 22, 2016 at 07:52:43AM -0800, Kevin Hilman wrote:
> >> >> Allow getting of subdevs from DT ports and endpoints.
> >> >>
> >> >> The _get_pdata() function was larely inspired by (i.e. stolen from)
> >> >
> >> > vpif_capture_get_pdata and "largely"?
> >>
> >> Yes, thanks.
> >>
> >> >> am437x-vpfe.c
> >> >>
> >> >> Signed-off-by: Kevin Hilman <khilman@xxxxxxxxxxxx>
> >> >> ---
> >> >> drivers/media/platform/davinci/vpif_capture.c | 130 +++++++++++++++++++++++++-
> >> >> include/media/davinci/vpif_types.h | 9 +-
> >> >> 2 files changed, 133 insertions(+), 6 deletions(-)
> >> >>
> >> >> diff --git a/drivers/media/platform/davinci/vpif_capture.c b/drivers/media/platform/davinci/vpif_capture.c
> >> >> index 94ee6cf03f02..47a4699157e7 100644
> >> >> --- a/drivers/media/platform/davinci/vpif_capture.c
> >> >> +++ b/drivers/media/platform/davinci/vpif_capture.c
> >> >> @@ -26,6 +26,8 @@
> >> >> #include <linux/slab.h>
> >> >>
> >> >> #include <media/v4l2-ioctl.h>
> >> >> +#include <media/v4l2-of.h>
> >> >> +#include <media/i2c/tvp514x.h>
> >> >
> >> > Do you need this header?
> >> >
> >>
> >> Yes, based on discussion with Hans, since there is no DT binding for
> >> selecting the input pins of the TVP514x, I have to select it in the
> >> driver, so I need the defines from this header. More on this below...
> >>
> >> >>
> >> >> #include "vpif.h"
> >> >> #include "vpif_capture.h"
> >> >> @@ -650,6 +652,10 @@ static int vpif_input_to_subdev(
> >> >>
> >> >> vpif_dbg(2, debug, "vpif_input_to_subdev\n");
> >> >>
> >> >> + if (!chan_cfg)
> >> >> + return -1;
> >> >> + if (input_index >= chan_cfg->input_count)
> >> >> + return -1;
> >> >> subdev_name = chan_cfg->inputs[input_index].subdev_name;
> >> >> if (subdev_name == NULL)
> >> >> return -1;
> >> >> @@ -657,7 +663,7 @@ static int vpif_input_to_subdev(
> >> >> /* loop through the sub device list to get the sub device info */
> >> >> for (i = 0; i < vpif_cfg->subdev_count; i++) {
> >> >> subdev_info = &vpif_cfg->subdev_info[i];
> >> >> - if (!strcmp(subdev_info->name, subdev_name))
> >> >> + if (subdev_info && !strcmp(subdev_info->name, subdev_name))
> >> >> return i;
> >> >> }
> >> >> return -1;
> >> >> @@ -1327,6 +1333,21 @@ static int vpif_async_bound(struct v4l2_async_notifier *notifier,
> >> >> {
> >> >> int i;
> >> >>
> >> >> + for (i = 0; i < vpif_obj.config->asd_sizes[0]; i++) {
> >> >> + struct v4l2_async_subdev *_asd = vpif_obj.config->asd[i];
> >> >> + const struct device_node *node = _asd->match.of.node;
> >> >> +
> >> >> + if (node == subdev->of_node) {
> >> >> + vpif_obj.sd[i] = subdev;
> >> >> + vpif_obj.config->chan_config->inputs[i].subdev_name =
> >> >> + (char *)subdev->of_node->full_name;
> >> >> + vpif_dbg(2, debug,
> >> >> + "%s: setting input %d subdev_name = %s\n",
> >> >> + __func__, i, subdev->of_node->full_name);
> >> >> + return 0;
> >> >> + }
> >> >> + }
> >> >> +
> >> >> for (i = 0; i < vpif_obj.config->subdev_count; i++)
> >> >> if (!strcmp(vpif_obj.config->subdev_info[i].name,
> >> >> subdev->name)) {
> >> >> @@ -1422,6 +1443,110 @@ static int vpif_async_complete(struct v4l2_async_notifier *notifier)
> >> >> return vpif_probe_complete();
> >> >> }
> >> >>
> >> >> +static struct vpif_capture_config *
> >> >> +vpif_capture_get_pdata(struct platform_device *pdev)
> >> >> +{
> >> >> + struct device_node *endpoint = NULL;
> >> >> + struct v4l2_of_endpoint bus_cfg;
> >> >> + struct vpif_capture_config *pdata;
> >> >> + struct vpif_subdev_info *sdinfo;
> >> >> + struct vpif_capture_chan_config *chan;
> >> >> + unsigned int i;
> >> >> +
> >> >> + dev_dbg(&pdev->dev, "vpif_get_pdata\n");
> >> >> +
> >> >> + if (!IS_ENABLED(CONFIG_OF) || !pdev->dev.of_node)
> >> >> + return pdev->dev.platform_data;
> >> >> +
> >> >> + pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
> >> >> + if (!pdata)
> >> >> + return NULL;
> >> >> + pdata->subdev_info =
> >> >> + devm_kzalloc(&pdev->dev, sizeof(*pdata->subdev_info) *
> >> >> + VPIF_CAPTURE_MAX_CHANNELS, GFP_KERNEL);
> >> >> +
> >> >> + if (!pdata->subdev_info)
> >> >> + return NULL;
> >> >> + dev_dbg(&pdev->dev, "%s\n", __func__);
> >> >> +
> >> >> + for (i = 0; ; i++) {
> >> >> + struct device_node *rem;
> >> >> + unsigned int flags;
> >> >> + int err;
> >> >> +
> >> >> + endpoint = of_graph_get_next_endpoint(pdev->dev.of_node,
> >> >> + endpoint);
> >> >> + if (!endpoint)
> >> >> + break;
> >> >> +
> >> >> + sdinfo = &pdata->subdev_info[i];
> >> >
> >> > subdev_info[] has got VPIF_CAPTURE_MAX_CHANNELS entries only.
> >> >
> >>
> >> Right, I need to make the loop only go for a max of
> >> VPIF_CAPTURE_MAX_CHANNELS iterations.
> >>
> >> >> + chan = &pdata->chan_config[i];
> >> >> + chan->inputs = devm_kzalloc(&pdev->dev,
> >> >> + sizeof(*chan->inputs) *
> >> >> + VPIF_DISPLAY_MAX_CHANNELS,
> >> >> + GFP_KERNEL);
> >> >> +
> >> >> + chan->input_count++;
> >> >> + chan->inputs[i].input.type = V4L2_INPUT_TYPE_CAMERA;
> >> >
> >> > I wonder what's the purpose of using index i on this array as well.
> >>
> >> The number of endpoints in DT is the number of input channels configured
> >> (up to a max of VPIF_CAPTURE_MAX_CHANNELS.)
> >>
> >> > If you use that to access a corresponding entry in a different array, I'd
> >> > just create a struct that contains the port configuration and the async
> >> > sub-device. The omap3isp driver does that, for instance; see
> >> > isp_of_parse_nodes() in drivers/media/platform/omap3isp/isp.c if you're
> >> > interested. Up to you.
> >>
> >> OK, I'll have a look at that driver. The goal here with this series is
> >> just to get this working with DT, but also not break the existing legacy
> >> platform_device support, so I'm trying not to mess with the
> >> driver-interal data structures too much.
> >
> > Ack.
> >
> >>
> >> >> + chan->inputs[i].input.std = V4L2_STD_ALL;
> >> >> + chan->inputs[i].input.capabilities = V4L2_IN_CAP_STD;
> >> >> +
> >> >> + /* FIXME: need a new property? ch0:composite ch1: s-video */
> >> >> + if (i == 0)
> >> >
> >> > Can you assume that the first endopoint has got a particular kind of input?
> >> > What if it's not connected?
> >>
> >> On all the boards I know of (there aren't many using this SoC), it's a
> >> safe assumption.
> >>
> >> > If this is a different physical port (not in the meaning another) in the
> >> > device, I'd use the reg property for this. Please see
> >> > Documentation/devicetree/bindings/media/video-interfaces.txt .
> >>
> >> My understanding (which is admittedly somewhat fuzzy) of the TVP514x is
> >> that it's not physically a different port. Instead, it's just telling
> >> the TVP514x which pin(s) will be active inputs (and what kind of signal
> >> will be present.)
> >>
> >> I'm open to a better way to describe this input select from DT, but
> >> based on what I heard from Hans, there isn't currently a good way to do
> >> that except for in the driver:
> >> (c.f. https://marc.info/?l=linux-arm-kernel&m=147887871615788)
> >>
> >> Based on further discussion in that thread, it sounds like there may be
> >> a way forward coming soon, and I'll be glad to switch to that when it
> >> arrives.
> >
> > I'm not sure that properly supporting connectors will provide any help here.
> >
> > Looking at the s_routing() API, it's the calling driver that has to be aware
> > of sub-device specific function parameters. As such it's not a very good
> > idea to require that a driver is aware of the value range of another
> > driver's parameter. I wonder if a simple enumeration interface would help
> > here --- if I understand correctly, the purpose is just to provide a way to
> > choose the input using VIDIOC_S_INPUT.
> >
> > I guess that's somehow ok as long as you have no other combinations of these
> > devices but this is hardly future-proof. (And certainly not a problem
> > created by this patch.)
>
> Yeah, this is far from future proof.
>
> > It'd be still nice to fix that as presumably we don't have the option of
> > reworking how we expect the device tree to look like.
>
> Agreed.
>
> I'm just hoping someone can shed som light on "how we expect the device
> tree to look". ;)
:-)
For the tvp514x, do you need more than a single endpoint on the receiver
side? Does the input that's selected affect the bus parameters?
If it doesn't, you could create a custom endpoint property for the possible
input values. The s_routing() really should be fixed though, but that could
be postponed I guess. There are quite a few drivers using it.
--
Kind regards,
Sakari Ailus
e-mail: sakari.ailus@xxxxxx XMPP: sailus@xxxxxxxxxxxxxx
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