Hi Sam,
On Sun, Oct 10, 2021 at 10:16:22AM +0200, Sam Ravnborg wrote:
> On Sun, Oct 10, 2021 at 12:41:52AM +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.
> >
> > Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
> > Signed-off-by: Marek Vasut <marex@xxxxxxx>
> > Cc: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
> > Cc: Sam Ravnborg <sam@xxxxxxxxxxxx>
> > To: dri-devel@xxxxxxxxxxxxxxxxxxxxx
>
> I am late to the game here - sorry. A few details in the following.
> With these considered:
> Reviewed-by: Sam Ravnborg <sam@xxxxxxxxxxxx>
>
> > ---
> > 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
> > V5: - Move the data-mapping property to port@0 , decoder LVDS input
> > - Add RB from Laurent
> > ---
> > 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 dcf579a4cf83..08091bab4857 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;
> > +
> > + 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.
>
> The missing data-mapping property is reported as an error, but this
> comments says it is OK. Info?
It's not a fatal error, probe still continues in backward-compatibility
mode. The message is there to tell that the DT should be updated. Would
you downgrade that to a warning ?
> > + */
> > + if (lvds_codec->connector_type != DRM_MODE_CONNECTOR_LVDS) {
> > + bus_node = of_graph_get_endpoint_by_regs(dev->of_node, 0, 0);
>
> Are there any reg specified in the binding? If not then the second
> parameter should be -1 here.
Yes, the DT node has two ports, with port 0 being the input. For LVDS
decoders, that's where the LVDS bus is.
> > + 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 {
>
> It would be nice with a helper for the below code if we need this a third
> time.
Where would you store it ?
> > + 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;
> > + }
>
> Add empty line here.
>
> > + lvds_codec->bridge.funcs = &funcs_decoder;
> > + }
> > + }
> > +
> > /*
> > * 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
