Hi Sakari,

Sakari Ailus [off-list ref] writes:

On Tue, Nov 22, 2016 at 07:52:43AM -0800, Kevin Hilman wrote:

quoted

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.

quoted

am437x-vpfe.c

Signed-off-by: Kevin Hilman <khilman-rdvid1DuHRBWk0Htik3J/w@public.gmane.org>
---
 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...

quoted

 
 #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.

quoted

+		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.

quoted

+		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.

quoted

+			chan->inputs[i].input_route = INPUT_CVBS_VI2B;
+		else
+			chan->inputs[i].input_route = INPUT_SVIDEO_VI2C_VI1C;
+		chan->inputs[i].output_route = OUTPUT_10BIT_422_EMBEDDED_SYNC;
+
+		err = v4l2_of_parse_endpoint(endpoint, &bus_cfg);
+		if (err) {
+			dev_err(&pdev->dev, "Could not parse the endpoint\n");
+			goto done;
+		}
+		dev_dbg(&pdev->dev, "Endpoint %s, bus_width = %d\n",
+			endpoint->full_name, bus_cfg.bus.parallel.bus_width);
+		flags = bus_cfg.bus.parallel.flags;
+
+		if (flags & V4L2_MBUS_HSYNC_ACTIVE_HIGH)
+			chan->vpif_if.hd_pol = 1;
+
+		if (flags & V4L2_MBUS_VSYNC_ACTIVE_HIGH)
+			chan->vpif_if.vd_pol = 1;
+
+		chan->vpif_if.if_type = VPIF_IF_BT656;
+		rem = of_graph_get_remote_port_parent(endpoint);
+		if (!rem) {
+			dev_dbg(&pdev->dev, "Remote device at %s not found\n",
+				endpoint->full_name);
+			goto done;
+		}
+
+		dev_dbg(&pdev->dev, "Remote device %s, %s found\n",
+			rem->name, rem->full_name);
+		sdinfo->name = rem->full_name;
+
+		pdata->asd[i] = devm_kzalloc(&pdev->dev,
+					     sizeof(struct v4l2_async_subdev),
+					     GFP_KERNEL);

Do you ensure somewhere that i isn't overrunning the pdata->asd[] array?
It's got VPIF_CAPTURE_MAX_CHANNELS entries.

Oops, no.  That will be fixed by making the outer for loop only iterate
for i = i..VPIF_CAPTURE_MAX_CHANNELS.


Thanks for the review,

Kevin
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