Hi Neil,
On Tue, May 26, 2020 at 02:50:21PM +0200, Neil Armstrong wrote:
> On 26/05/2020 03:15, Laurent Pinchart wrote:
> > On all platforms except i.MX and Rockchip, the dw-hdmi DT bindings
> > require a video output port connected to an HDMI sink (most likely an
> > HDMI connector, in rare cases another bridges converting HDMI to another
> > protocol). For those platforms, retrieve the next bridge and attach it
> > from the dw-hdmi bridge attach handler.
> >
> > Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@xxxxxxxxxxxxxxxx>
> > ---
> > drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 52 ++++++++++++++++++++++-
> > include/drm/bridge/dw_hdmi.h | 2 +
> > 2 files changed, 53 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
> > index 6148a022569a..512e67bb1c32 100644
> > --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
> > +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
> > @@ -143,6 +143,7 @@ struct dw_hdmi_phy_data {
> > struct dw_hdmi {
> > struct drm_connector connector;
> > struct drm_bridge bridge;
> > + struct drm_bridge *next_bridge;
> >
> > unsigned int version;
> >
> > @@ -2797,7 +2798,8 @@ static int dw_hdmi_bridge_attach(struct drm_bridge *bridge,
> > struct dw_hdmi *hdmi = bridge->driver_private;
> >
> > if (flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR)
> > - return 0;
> > + return drm_bridge_attach(bridge->encoder, hdmi->next_bridge,
> > + bridge, flags);
> >
> > return dw_hdmi_connector_create(hdmi);
> > }
> > @@ -3179,6 +3181,50 @@ static void dw_hdmi_init_hw(struct dw_hdmi *hdmi)
> > hdmi->phy.ops->setup_hpd(hdmi, hdmi->phy.data);
> > }
> >
> > +static int dw_hdmi_parse_dt(struct dw_hdmi *hdmi)
> > +{
> > + struct device_node *endpoint;
> > + struct device_node *remote;
> > +
> > + if (!hdmi->plat_data->output_port)
> > + return 0;
> > +
> > + endpoint = of_graph_get_endpoint_by_regs(hdmi->dev->of_node,
> > + hdmi->plat_data->output_port,
> > + -1);
> > + if (!endpoint) {
> > + /*
> > + * Don't treat this as a fatal error as the Rockchip DW-HDMI
> > + * binding doesn't make the output port mandatory.
> > + */
> > + dev_dbg(hdmi->dev, "Missing endpoint in port@%u\n",
> > + hdmi->plat_data->output_port);
> > + return 0;
> > + }
> > +
> > + remote = of_graph_get_remote_port_parent(endpoint);
> > + of_node_put(endpoint);
> > + if (!remote) {
> > + dev_err(hdmi->dev, "Endpoint in port@%u unconnected\n",
> > + hdmi->plat_data->output_port);
> > + return -ENODEV;
> > + }
> > +
> > + if (!of_device_is_available(remote)) {
> > + dev_err(hdmi->dev, "port@%u remote device is disabled\n",
> > + hdmi->plat_data->output_port);
> > + of_node_put(remote);
> > + return -ENODEV;
> > + }
> > +
> > + hdmi->next_bridge = of_drm_find_bridge(remote);
> > + of_node_put(remote);
> > + if (!hdmi->next_bridge)
> > + return -EPROBE_DEFER;
>
> I'll be safer to print a warn for now until all platforms has been tested.
Probe deferral isn't an error though, it can happen in normal
conditions, if the next bridge hasn't been probed yet. A WARN_ON() would
be pretty bad in that case, and even a dev_warn() may generate
unnecessary worry.
Given that this code only runs if hdmi->plat_data->output_port != 0, and
only the rcar-du driver sets the output_port field, I think it's safe to
not print any message.
> > +
> > + return 0;
> > +}
> > +
> > static struct dw_hdmi *
> > __dw_hdmi_probe(struct platform_device *pdev,
> > const struct dw_hdmi_plat_data *plat_data)
> > @@ -3216,6 +3262,10 @@ __dw_hdmi_probe(struct platform_device *pdev,
> > mutex_init(&hdmi->cec_notifier_mutex);
> > spin_lock_init(&hdmi->audio_lock);
> >
> > + ret = dw_hdmi_parse_dt(hdmi);
> > + if (ret < 0)
> > + return ERR_PTR(ret);
> > +
> > ddc_node = of_parse_phandle(np, "ddc-i2c-bus", 0);
> > if (ddc_node) {
> > hdmi->ddc = of_get_i2c_adapter_by_node(ddc_node);
> > diff --git a/include/drm/bridge/dw_hdmi.h b/include/drm/bridge/dw_hdmi.h
> > index ea34ca146b82..8ebeb65d6371 100644
> > --- a/include/drm/bridge/dw_hdmi.h
> > +++ b/include/drm/bridge/dw_hdmi.h
> > @@ -126,6 +126,8 @@ struct dw_hdmi_phy_ops {
> > struct dw_hdmi_plat_data {
> > struct regmap *regm;
> >
> > + unsigned int output_port;
> > +
> > unsigned long input_bus_encoding;
> > bool use_drm_infoframe;
> > bool ycbcr_420_allowed;
> >
>
> I must check on meson, since I'm not sure for now if the connector probes.
>
> Anyway, this looks fine.
>
> Reviewed-by: Neil Armstrong <narmstrong@xxxxxxxxxxxx>
--
Regards,
Laurent Pinchart
