Hi Marek,
Thank you for the patch, and all my apologies for the delay.
On Tue, Jul 27, 2021 at 06:13:57PM +0200, Marek Vasut wrote:
> Decoder input LVDS format is a property of the decoder chip or even
> its strapping. Handle data-mapping the same way lvds-panel does. In
> case data-mapping is not present, do nothing, since there are still
> legacy bindings which do not specify this property.
>
> Signed-off-by: Marek Vasut <marex@xxxxxxx>
> Cc: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
> Cc: Sam Ravnborg <sam@xxxxxxxxxxxx>
> To: dri-devel@xxxxxxxxxxxxxxxxxxxxx
> ---
> V2: - Move the data-mapping to endpoint
> V3: - Rebase on V2 submitted a while ago, reinstate changelog
> - Use .atomic_get_input_bus_fmts for the decoder, separate funcs for encoder
> V4: - No change
> ---
> drivers/gpu/drm/bridge/lvds-codec.c | 76 ++++++++++++++++++++++++++++-
> 1 file changed, 75 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/bridge/lvds-codec.c b/drivers/gpu/drm/bridge/lvds-codec.c
> index dcf579a4cf833..afa7ce7ea01e8 100644
> --- a/drivers/gpu/drm/bridge/lvds-codec.c
> +++ b/drivers/gpu/drm/bridge/lvds-codec.c
> @@ -12,6 +12,7 @@
> #include <linux/platform_device.h>
> #include <linux/regulator/consumer.h>
>
> +#include <drm/drm_atomic_helper.h>
> #include <drm/drm_bridge.h>
> #include <drm/drm_panel.h>
>
> @@ -22,6 +23,7 @@ struct lvds_codec {
> struct regulator *vcc;
> struct gpio_desc *powerdown_gpio;
> u32 connector_type;
> + unsigned int bus_format;
> };
>
> static inline struct lvds_codec *to_lvds_codec(struct drm_bridge *bridge)
> @@ -74,12 +76,50 @@ static const struct drm_bridge_funcs funcs = {
> .disable = lvds_codec_disable,
> };
>
> +#define MAX_INPUT_SEL_FORMATS 1
> +static u32 *
> +lvds_codec_atomic_get_input_bus_fmts(struct drm_bridge *bridge,
> + struct drm_bridge_state *bridge_state,
> + struct drm_crtc_state *crtc_state,
> + struct drm_connector_state *conn_state,
> + u32 output_fmt,
> + unsigned int *num_input_fmts)
> +{
> + struct lvds_codec *lvds_codec = to_lvds_codec(bridge);
> + u32 *input_fmts;
> +
> + *num_input_fmts = 0;
> +
> + input_fmts = kcalloc(MAX_INPUT_SEL_FORMATS, sizeof(*input_fmts),
> + GFP_KERNEL);
> + if (!input_fmts)
> + return NULL;
> +
> + input_fmts[0] = lvds_codec->bus_format;
> + *num_input_fmts = MAX_INPUT_SEL_FORMATS;
Are there cases where the input format would depend on the output format
? For instance, a 24-bit RGB output that could also work in RGB666 mode,
where we would select between MEDIA_BUS_FMT_RGB666_1X7X3_SPWG and
MEDIA_BUS_FMT_RGB888_1X7X4_SPWG depending on whether the output is
RGB666 or RGB888 ? I don't think we need to handle this now, and I
believe it will be possible to do this in a backward-compatible way if
the need ever arises. A confirmation that I'm not missing something
obvious would be nice.
> +
> + return input_fmts;
> +}
> +
> +static const struct drm_bridge_funcs funcs_decoder = {
> + .attach = lvds_codec_attach,
> + .enable = lvds_codec_enable,
> + .disable = lvds_codec_disable,
> + .atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state,
> + .atomic_destroy_state = drm_atomic_helper_bridge_destroy_state,
> + .atomic_reset = drm_atomic_helper_bridge_reset,
> + .atomic_get_input_bus_fmts = lvds_codec_atomic_get_input_bus_fmts,
> +};
> +
> static int lvds_codec_probe(struct platform_device *pdev)
> {
> struct device *dev = &pdev->dev;
> struct device_node *panel_node;
> + struct device_node *bus_node;
> struct drm_panel *panel;
> struct lvds_codec *lvds_codec;
> + const char *mapping;
> + int ret;
>
> lvds_codec = devm_kzalloc(dev, sizeof(*lvds_codec), GFP_KERNEL);
> if (!lvds_codec)
> @@ -119,13 +159,47 @@ static int lvds_codec_probe(struct platform_device *pdev)
> if (IS_ERR(lvds_codec->panel_bridge))
> return PTR_ERR(lvds_codec->panel_bridge);
>
> + lvds_codec->bridge.funcs = &funcs;
> +
> + /*
> + * Decoder input LVDS format is a property of the decoder chip or even
> + * its strapping. Handle data-mapping the same way lvds-panel does. In
> + * case data-mapping is not present, do nothing, since there are still
> + * legacy bindings which do not specify this property.
> + */
> + if (lvds_codec->connector_type != DRM_MODE_CONNECTOR_LVDS) {
> + bus_node = of_graph_get_endpoint_by_regs(dev->of_node, 1, 0);
I think this should be
bus_node = of_graph_get_endpoint_by_regs(dev->of_node, 0, 0);
(see the comment on patch 1/2).
> + if (!bus_node) {
> + dev_dbg(dev, "bus DT node not found\n");
> + return -ENXIO;
> + }
> +
> + ret = of_property_read_string(bus_node, "data-mapping",
> + &mapping);
> + of_node_put(bus_node);
> + if (ret < 0) {
> + dev_err(dev, "missing 'data-mapping' DT property\n");
> + } else {
> + if (!strcmp(mapping, "jeida-18")) {
> + lvds_codec->bus_format = MEDIA_BUS_FMT_RGB666_1X7X3_SPWG;
> + } else if (!strcmp(mapping, "jeida-24")) {
> + lvds_codec->bus_format = MEDIA_BUS_FMT_RGB888_1X7X4_JEIDA;
> + } else if (!strcmp(mapping, "vesa-24")) {
> + lvds_codec->bus_format = MEDIA_BUS_FMT_RGB888_1X7X4_SPWG;
> + } else {
> + dev_err(dev, "invalid 'data-mapping' DT property\n");
> + return -EINVAL;
> + }
> + lvds_codec->bridge.funcs = &funcs_decoder;
> + }
I may have split this to a separate function to reduce line length and
simplify error handling, up to you.
With at least the port number fix above (unless I'm mistaken of course),
Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
> + }
> +
> /*
> * 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.
> */
> lvds_codec->bridge.of_node = dev->of_node;
> - lvds_codec->bridge.funcs = &funcs;
> drm_bridge_add(&lvds_codec->bridge);
>
> platform_set_drvdata(pdev, lvds_codec);
--
Regards,
Laurent Pinchart
