From a3c477b33d6cf015fed50fe5ee23f57e2d579ef4 Mon Sep 17 00:00:00 2001 From: Laurent Pinchart Date: Sat, 22 Oct 2016 19:05:53 +0300 Subject: [PATCH] drm: rcar-du: Fix dot clock routing configuration Dot clock routing is setup through different registers depending on the DU generation. The code has been designed for Gen2 and hasn't been updated since. This works thanks to good reset default value, but isn't very safe. Fix it. Signed-off-by: Laurent Pinchart --- drivers/gpu/drm/rcar-du/rcar_du_group.c | 22 +++++++++++++--------- 1 file changed, 13 insertions(+), 9 deletions(-) diff --git a/drivers/gpu/drm/rcar-du/rcar_du_group.c b/drivers/gpu/drm/rcar-du/rcar_du_group.c index 33b2fc53da3e..64738fca96d0 100644 --- a/drivers/gpu/drm/rcar-du/rcar_du_group.c +++ b/drivers/gpu/drm/rcar-du/rcar_du_group.c @@ -105,16 +105,20 @@ static void rcar_du_group_setup(struct rcar_du_group *rgrp) if (rcar_du_has(rgrp->dev, RCAR_DU_FEATURE_EXT_CTRL_REGS)) { rcar_du_group_setup_defr8(rgrp); - /* Configure input dot clock routing. We currently hardcode the - * configuration to routing DOTCLKINn to DUn. + /* + * Configure input dot clock routing. We currently hardcode the + * configuration to routing DOTCLKINn to DUn. Register fields + * depend on the DU generation, but the resulting value is 0 in + * all cases. + * + * On Gen2 a single register in the first group controls dot + * clock selection for all channels, while on Gen3 dot clocks + * are setup through per-group registers, only available when + * the group has two channels. */ - rcar_du_group_write(rgrp, DIDSR, DIDSR_CODE | - DIDSR_LCDS_DCLKIN(2) | - DIDSR_LCDS_DCLKIN(1) | - DIDSR_LCDS_DCLKIN(0) | - DIDSR_PDCS_CLK(2, 0) | - DIDSR_PDCS_CLK(1, 0) | - DIDSR_PDCS_CLK(0, 0)); + if ((rcdu->info->gen < 3 && rgrp->index == 0) || + (rcdu->info->gen == 3 && rgrp->num_crtcs > 1)) + rcar_du_group_write(rgrp, DIDSR, DIDSR_CODE); } if (rcdu->info->gen >= 3) -- 2.20.1