On Wed, Jul 11, 2018 at 4:35 AM, Jernej Skrabec <jernej.skrabec@xxxxxxxx> wrote: > Currently, TCON supports 2 ways to match TCON with engine (mixer in this > case). Old way is to just traverse of graph backwards and compare node > pointer. New way is to match TCON and engine by their respective ids. > All SoCs with DE2 enabled till now used the old way, which means mixer > id was never used and thus never implemented. > > However, for R40, only the new way will be used. To prepare for that, > implement mixer id fetching from DT. > > Signed-off-by: Jernej Skrabec <jernej.skrabec@xxxxxxxx> > --- > drivers/gpu/drm/sun4i/sun8i_mixer.c | 40 +++++++++++++++++++++++++++-- > 1 file changed, 38 insertions(+), 2 deletions(-) > > diff --git a/drivers/gpu/drm/sun4i/sun8i_mixer.c b/drivers/gpu/drm/sun4i/sun8i_mixer.c > index aa81b9838ae8..4bd4d8ccb34f 100644 > --- a/drivers/gpu/drm/sun4i/sun8i_mixer.c > +++ b/drivers/gpu/drm/sun4i/sun8i_mixer.c > @@ -22,6 +22,7 @@ > #include <linux/component.h> > #include <linux/dma-mapping.h> > #include <linux/of_device.h> > +#include <linux/of_graph.h> > #include <linux/reset.h> > > #include "sun4i_drv.h" > @@ -322,6 +323,42 @@ static struct regmap_config sun8i_mixer_regmap_config = { > .max_register = 0xbfffc, /* guessed */ > }; > > +static int sun8i_mixer_of_get_id(struct device_node *node) > +{ > + struct device_node *port, *ep; > + int ret = -EINVAL; > + > + /* output is port 1 */ > + port = of_graph_get_port_by_id(node, 1); > + if (!port) > + return -EINVAL; > + > + /* try to find downstream endpoint */ > + for_each_available_child_of_node(port, ep) { > + struct device_node *remote; > + u32 reg; > + > + remote = of_graph_get_remote_endpoint(ep); > + if (!remote) > + continue; > + > + ret = of_property_read_u32(remote, "reg", ®); > + if (!ret) { > + of_node_put(remote); > + of_node_put(ep); > + of_node_put(port); > + > + return reg; > + } > + > + of_node_put(remote); > + } > + > + of_node_put(port); > + > + return ret; > +} > + The above looks good. > static int sun8i_mixer_bind(struct device *dev, struct device *master, > void *data) > { > @@ -353,8 +390,7 @@ static int sun8i_mixer_bind(struct device *dev, struct device *master, > dev_set_drvdata(dev, mixer); > mixer->engine.ops = &sun8i_engine_ops; > mixer->engine.node = dev->of_node; > - /* The ID of the mixer currently doesn't matter */ > - mixer->engine.id = -1; > + mixer->engine.id = sun8i_mixer_of_get_id(dev->of_node); Should you be handling error codes? ChenYu -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html