lkml.org 
[lkml]   [2018]   [Mar]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
SubjectRe: [PATCH v2 4/5] drm: bridge: lvds-encoder: allow specifying the input bus format
Hi Peter, Laurent,
thanks for the patches,

On Mon, Mar 26, 2018 at 11:24:46PM +0200, Peter Rosin wrote:
> If the bridge changes the bus format, allow this to be described in
> the bridge, instead of providing false information about the bus
> format of the connector or panel.
>
> Signed-off-by: Peter Rosin <peda@axentia.se>
> ---
> .../bindings/display/bridge/lvds-transmitter.txt | 6 ++++++
> drivers/gpu/drm/bridge/lvds-encoder.c | 25 ++++++++++++++++++++++
> 2 files changed, 31 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/display/bridge/lvds-transmitter.txt b/Documentation/devicetree/bindings/display/bridge/lvds-transmitter.txt
> index 50220190c203..8d40a2069252 100644
> --- a/Documentation/devicetree/bindings/display/bridge/lvds-transmitter.txt
> +++ b/Documentation/devicetree/bindings/display/bridge/lvds-transmitter.txt
> @@ -30,6 +30,12 @@ Required properties:
> device-specific version corresponding to the device first
> followed by the generic version.
>
> +Optional properties:
> +
> +- interface-pix-fmt:
> + List of valid input bus formats of the encoder. Recognized bus formats
> + are listed in ../bus-format.txt
> +

This comments applies here and to [3/5] as well.

Are we sure we want the supported bridge input format defined in DT
bindings?

Again, I may be biased, but as I see this, each bridge driver should
list its supported formats with MEDIA_BUS_FMT_ fourcc codes and return
the currently 'active' one when requested by the preceding bridge.

I understand for this driver, being compatible with both a generic lvds
encoder and a specific chip, the supported input formats are
different, but I would have used the 'of_device_id.data' field for
this and leave this out from DT bindings.

This makes the translation routine here implemented not required if
I'm not wrong...

Thanks
j

> Required nodes:
>
> This device has two video ports. Their connections are modeled using the OF
> diff --git a/drivers/gpu/drm/bridge/lvds-encoder.c b/drivers/gpu/drm/bridge/lvds-encoder.c
> index 75b0d3f6e4de..b78619b5560a 100644
> --- a/drivers/gpu/drm/bridge/lvds-encoder.c
> +++ b/drivers/gpu/drm/bridge/lvds-encoder.c
> @@ -9,6 +9,7 @@
>
> #include <drm/drmP.h>
> #include <drm/drm_bridge.h>
> +#include <drm/drm_of.h>
> #include <drm/drm_panel.h>
>
> #include <linux/of_graph.h>
> @@ -16,6 +17,8 @@
> struct lvds_encoder {
> struct drm_bridge bridge;
> struct drm_bridge *panel_bridge;
> + int num_bus_formats;
> + u32 *bus_formats;
> };
>
> static int lvds_encoder_attach(struct drm_bridge *bridge)
> @@ -28,8 +31,22 @@ static int lvds_encoder_attach(struct drm_bridge *bridge)
> bridge);
> }
>
> +static int lvds_encoder_input_formats(struct drm_bridge *bridge,
> + const u32 **bus_formats)
> +{
> + struct lvds_encoder *lvds_encoder = container_of(bridge,
> + struct lvds_encoder,
> + bridge);
> +
> + if (lvds_encoder->num_bus_formats)
> + *bus_formats = lvds_encoder->bus_formats;
> +
> + return lvds_encoder->num_bus_formats;
> +}
> +
> static struct drm_bridge_funcs funcs = {
> .attach = lvds_encoder_attach,
> + .input_formats = lvds_encoder_input_formats,
> };
>
> static int lvds_encoder_probe(struct platform_device *pdev)
> @@ -39,6 +56,7 @@ static int lvds_encoder_probe(struct platform_device *pdev)
> struct device_node *panel_node;
> struct drm_panel *panel;
> struct lvds_encoder *lvds_encoder;
> + int ret;
>
> lvds_encoder = devm_kzalloc(&pdev->dev, sizeof(*lvds_encoder),
> GFP_KERNEL);
> @@ -79,6 +97,12 @@ static int lvds_encoder_probe(struct platform_device *pdev)
> if (IS_ERR(lvds_encoder->panel_bridge))
> return PTR_ERR(lvds_encoder->panel_bridge);
>
> + ret = drm_of_bus_formats(pdev->dev.of_node, "interface-pix-fmt",
> + &lvds_encoder->bus_formats);
> + if (ret < 0)
> + return ret;
> + lvds_encoder->num_bus_formats = ret;
> +
> /* The panel_bridge bridge is attached to the panel's of_node,
> * but we need a bridge attached to our of_node for our user
> * to look up.
> @@ -96,6 +120,7 @@ static int lvds_encoder_remove(struct platform_device *pdev)
> {
> struct lvds_encoder *lvds_encoder = platform_get_drvdata(pdev);
>
> + kfree(lvds_encoder->bus_formats);
> drm_bridge_remove(&lvds_encoder->bridge);
>
> return 0;
> --
> 2.11.0
>
[unhandled content-type:application/pgp-signature]
\
 
 \ /
  Last update: 2018-03-27 12:28    [W:0.092 / U:23.752 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site