Re: [PATCH v1 1/2] drm/msm/dp: Add support for SC7280 eDP

From: Stephen Boyd <swboyd@chromium.org>
To: Sankeerth Billakanti <sbillaka@codeaurora.org>,
	dri-devel@lists.freedesktop.org,
	 freedreno@lists.freedesktop.org, linux-arm-msm@vger.kernel.org,
	 linux-kernel@vger.kernel.org
Cc: robdclark@gmail.com, seanpaul@chromium.org,
	kalyan_t@codeaurora.org,  abhinavk@codeaurora.org,
	dianders@chromium.org, khsieh@codeaurora.org,
	 mkrishn@codeaurora.org
Subject: Re: [PATCH v1 1/2] drm/msm/dp: Add support for SC7280 eDP
Date: Mon, 13 Sep 2021 20:53:32 -0700	[thread overview]
Message-ID: <CAE-0n51EiVHB56AC5tdyRtkpy0B9OuOp_y5xBceaU_pyzr+_JA@mail.gmail.com> (raw)
In-Reply-To: <1628726882-27841-2-git-send-email-sbillaka@codeaurora.org>

Quoting Sankeerth Billakanti (2021-08-11 17:08:01)
> The eDP controller on SC7280 is similar to the eDP/DP controllers
> supported by the current driver implementation.
>
> SC7280 supports one EDP and one DP controller which can operate
> concurrently.
>
> The following are some required changes for the sc7280 sink:
> 1. Additional gpio configuration for backlight and pwm via pmic.
> 2. ASSR support programming on the sink.
> 3. SSC support programming on the sink.
>
> Signed-off-by: Sankeerth Billakanti <sbillaka@codeaurora.org>
> ---
>  drivers/gpu/drm/msm/disp/dpu1/dpu_hw_catalog.c |  4 ++--
>  drivers/gpu/drm/msm/dp/dp_ctrl.c               | 19 +++++++++++++++
>  drivers/gpu/drm/msm/dp/dp_display.c            | 32 ++++++++++++++++++++++++--
>  drivers/gpu/drm/msm/dp/dp_parser.c             | 31 +++++++++++++++++++++++++
>  drivers/gpu/drm/msm/dp/dp_parser.h             |  5 ++++
>  5 files changed, 87 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_catalog.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_catalog.c
> index b131fd37..1096c44 100644
> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_catalog.c
> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_catalog.c
> @@ -856,9 +856,9 @@ static const struct dpu_intf_cfg sm8150_intf[] = {
>  };
>
>  static const struct dpu_intf_cfg sc7280_intf[] = {
> -       INTF_BLK("intf_0", INTF_0, 0x34000, INTF_DP, 0, 24, INTF_SC7280_MASK, MDP_SSPP_TOP0_INTR, 24, 25),
> +       INTF_BLK("intf_0", INTF_0, 0x34000, INTF_DP, 1, 24, INTF_SC7280_MASK, MDP_SSPP_TOP0_INTR, 24, 25),
>         INTF_BLK("intf_1", INTF_1, 0x35000, INTF_DSI, 0, 24, INTF_SC7280_MASK, MDP_SSPP_TOP0_INTR, 26, 27),
> -       INTF_BLK("intf_5", INTF_5, 0x39000, INTF_EDP, 0, 24, INTF_SC7280_MASK, MDP_SSPP_TOP0_INTR, 22, 23),
> +       INTF_BLK("intf_5", INTF_5, 0x39000, INTF_DP, 0, 24, INTF_SC7280_MASK, MDP_SSPP_TOP0_INTR, 22, 23),

Why is this INTF_5? Instead of INTF_2? I noticed that if I changed it to
INTF_2 that I could get external DP to work but not the internal eDP.
Then changing it back to INTF_5 got eDP interface working but not DP. I
also noticed that we changed it from INTF_EDP to INTF_DP for the eDP
hardware. Can you please explain this struct? I looked at it and I still
don't understand what's going on.

The index (fifth element above) seems to need to match the index that is
set for the address in sc7280_edp_cfg[]. If the two don't match things
don't seem to work either. But then I also tried flipping that and still
things didn't work. Does that index matter? Or can the first INTF_DP be
0 still?