[v2,0/4] Fix A64/R40 HDMI PHY device tree binding

Message

Icenowy Zheng Sept. 16, 2018, 4:34 a.m. UTC

When adding support for A64 HDMI PHY in 4.19, we assumed that the two
PLL-VIDEOs can both feed the HDMI PHY clock. However experiments show
that the mux bit discovered in R40 blob is not applicable on A64. This
is not discovered, as normally with a single display pipeline only
PLL-VIDEO0 will be used.

In this patchset the second PLL is dropped, and a binding specially for
R40 HDMI PHY is added (which seems to have the mux).

PATCH 1 is dropping second PLL for A64 HDMI PHY, and PATCH 2 to 4
are adding R40 HDMI PHY binding, as R40 behaves differently with A64
with this.

This patchset targets v4.19 fixes tree, because the binding is
introduced in v4.19, and if we don't fix it there a wrong binding will
be left in a stable version released. A64 display pipeline support is
not yet in v4.19, but R40 support is in it.

Icenowy Zheng (4):
  drm: sun4i: drop second PLL from A64 HDMI PHY
  dt-bindings: sun4i-drm: add compatible for R40 HDMI PHY
  drm/sun4i: add support for R40 HDMI PHY
  ARM: sun8i: dts: drop A64 HDMI PHY fallback compatible from R40 DT

 .../devicetree/bindings/display/sunxi/sun4i-drm.txt |  5 +++--
 arch/arm/boot/dts/sun8i-r40.dtsi                    |  3 +--
 drivers/gpu/drm/sun4i/sun8i_hdmi_phy.c              | 13 ++++++++++++-
 3 files changed, 16 insertions(+), 5 deletions(-)

Comments

Maxime Ripard Sept. 19, 2018, 9:32 a.m. UTC | #1

On Sun, Sep 16, 2018 at 12:34:05PM +0800, Icenowy Zheng wrote:
> When adding support for A64 HDMI PHY in 4.19, we assumed that the two
> PLL-VIDEOs can both feed the HDMI PHY clock. However experiments show
> that the mux bit discovered in R40 blob is not applicable on A64. This
> is not discovered, as normally with a single display pipeline only
> PLL-VIDEO0 will be used.
> 
> In this patchset the second PLL is dropped, and a binding specially for
> R40 HDMI PHY is added (which seems to have the mux).
> 
> PATCH 1 is dropping second PLL for A64 HDMI PHY, and PATCH 2 to 4
> are adding R40 HDMI PHY binding, as R40 behaves differently with A64
> with this.
> 
> This patchset targets v4.19 fixes tree, because the binding is
> introduced in v4.19, and if we don't fix it there a wrong binding will
> be left in a stable version released. A64 display pipeline support is
> not yet in v4.19, but R40 support is in it.

Applied 1 and 4 as fixes for 4.19, 2 and 3 for 4.20, since they are
not fixes per se, and the R40 display engine is not enabled in 4.19
anyway.

Maxime