Hi Kieran, On Friday, 7 December 2018 14:50:47 EET Kieran Bingham wrote: > On 25/11/2018 14:40, Laurent Pinchart wrote: > > DU channels are routed to DPAD outputs in an SoC-dependent way. The > > routing can be fixed (e.g. DU3 to DPAD0 on H3) or configurable (e.g. DU0 > > or DU1 to DPAD0 on D3/E3). The hardware offers no option to disconnect > > DPAD outputs, which are thus always driven by a DU channel. > > > > On SoCs that have less DU channels than DU outputs, such as D3 and E3, > > the DPAD output is always driven when all channels are in used by other > > s/used/use/ > > > outputs (such as the internal LVDS and HDMI encoders). This creates an > > unwanted clone on the DPAD output. > > > > However, the parallel output of the DU channels routed to DPAD can be > > set to fixed levels in the DU channels themselves through the DOFLR > > group register. Use this to turn the DPAD on or off by driving fixed > > signals at the output of any DU channel not routed to a DPAD output. > > This doesn't affect the DU output signals going to other outputs. > > > > Signed-off-by: Laurent Pinchart > > <laurent.pinchart+renesas@xxxxxxxxxxxxxxxx> > > Only spelling and bikeshedding here - so: > > Reviewed-by: Kieran Bingham <kieran.bingham+renesas@xxxxxxxxxxxxxxxx> > > > --- > > > > drivers/gpu/drm/rcar-du/rcar_du_group.c | 42 +++++++++++++++++++++++++ > > 1 file changed, 42 insertions(+) > > > > diff --git a/drivers/gpu/drm/rcar-du/rcar_du_group.c > > b/drivers/gpu/drm/rcar-du/rcar_du_group.c index > > 7e440f61977f..5aaf41b7a2ca 100644 > > --- a/drivers/gpu/drm/rcar-du/rcar_du_group.c > > +++ b/drivers/gpu/drm/rcar-du/rcar_du_group.c > > @@ -287,6 +287,46 @@ int rcar_du_set_dpad0_vsp1_routing(struct > > rcar_du_device *rcdu) > > return 0; > > } > > > > +static void rcar_du_group_set_output_levels(struct rcar_du_group *rgrp) > > +{ > > + static const u32 doflr_values[2] = { > > + DOFLR_HSYCFL0 | DOFLR_VSYCFL0 | DOFLR_ODDFL0 | > > + DOFLR_DISPFL0 | DOFLR_CDEFL0 | DOFLR_RGBFL0, > > + DOFLR_HSYCFL1 | DOFLR_VSYCFL1 | DOFLR_ODDFL1 | > > + DOFLR_DISPFL1 | DOFLR_CDEFL1 | DOFLR_RGBFL1, > > + }; > > + static const u32 dpad_mask = BIT(RCAR_DU_OUTPUT_DPAD1) > > + | BIT(RCAR_DU_OUTPUT_DPAD0); > > + struct rcar_du_device *rcdu = rgrp->dev; > > + u32 doflr = DOFLR_CODE; > > + unsigned int i; > > + > > + if (rcdu->info->gen < 2) > > + return; > > + > > + /* > > + * The DPAD outputs can't be controlled directly. However, the parallel > > + * output of the DU channels routed to DPAD can be set to fixed levels > > + * through the DOFLR group register. Use this to turn the DPAD on or off > > + * by driving fixed signals at the output of any DU channel not routed > > + * to a DPAD output. This doesn't affect the DU output signals going to > > + * other outputs, such as the internal LVDS and HDMI encoders. > > Perhaps more out of interest - what /fixed/ levels do we output. > High/Low/Hi-Z ? It's low-level, I'll update the comment. > > + */ > > + > > + for (i = 0; i < rgrp->num_crtcs; ++i) { > > + struct rcar_du_crtc_state *rstate; > > + struct rcar_du_crtc *rcrtc; > > + > > + rcrtc = &rcdu->crtcs[rgrp->index * 2 + i];> + rstate = > > to_rcar_crtc_state(rcrtc->crtc.state); + > > + if (!(rstate->outputs & dpad_mask)) > > + doflr |= doflr_values[i];> + } > > + > > + rcar_du_group_write(rgrp, DOFLR, doflr); > > +} > > + > > > > int rcar_du_group_set_routing(struct rcar_du_group *rgrp) > > { > > > > struct rcar_du_device *rcdu = rgrp->dev; > > > > @@ -306,5 +346,7 @@ int rcar_du_group_set_routing(struct rcar_du_group > > *rgrp)> > > rcar_du_group_write(rgrp, DORCR, dorcr); > > > > + rcar_du_group_set_output_levels(rgrp); > > Shouldn't this be: > > rcar_du_group_set_dpad_levels() > > Anyway - that's just bikeshedding - I'll leave the decision (even if > that's keeping this as is) to you. Good idea, I'll rename the function. > > + > > > > return rcar_du_set_dpad0_vsp1_routing(rgrp->dev); > > > > } -- Regards, Laurent Pinchart