Re: [Freedreno] [PATCH 4/4] drm/msm/dp: Add support for SC8180x eDP

From: abhinavk@codeaurora.org
To: Bjorn Andersson <bjorn.andersson@linaro.org>
Cc: Rob Clark <robdclark@gmail.com>, Sean Paul <sean@poorly.run>,
	David Airlie <airlied@linux.ie>, Daniel Vetter <daniel@ffwll.ch>,
	Stephen Boyd <swboyd@chromium.org>,
	sbillaka@codeaurora.org, Tanmay Shah <tanmay@codeaurora.org>,
	linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org,
	dri-devel@lists.freedesktop.org,
	Dmitry Baryshkov <dmitry.baryshkov@linaro.org>,
	freedreno@lists.freedesktop.org,
	Chandan Uddaraju <chandanu@codeaurora.org>
Subject: Re: [Freedreno] [PATCH 4/4] drm/msm/dp: Add support for SC8180x eDP
Date: Fri, 28 May 2021 16:40:32 -0700	[thread overview]
Message-ID: <a1a8221a44edc3a509bdc1bb89bb5a97@codeaurora.org> (raw)
In-Reply-To: <20210511042043.592802-5-bjorn.andersson@linaro.org>

On 2021-05-10 21:20, Bjorn Andersson wrote:
> The eDP controller found in SC8180x is at large compatible with the
> current implementation, but has its register blocks at slightly
> different offsets.
> 
> Add the compatible and the new register layout.
> 
I am not able to completely recall the history of why in the DP bindings
we added DP register base as a big hunk and let catalog handle the 
submodule
offsets.

I guess earlier that made sense because DP sub-block offsets were fixed.
But if we plan to re-use the DP driver for eDP as well like this series, 
then maybe it might be
better if this comes from device tree like the earlier version was 
planning to

https://patchwork.kernel.org/project/dri-devel/patch/0101016ec6ddf446-e87ab1ce-5cbf-40a0-a0bb-cd0151cd577a-000000@us-west-2.amazonses.com/

+- reg:                  Base address and length of DP hardware's memory 
mapped regions.
+- cell-index:           Specifies the controller instance.
+- reg-names:            A list of strings that name the list of regs.
+			"dp_ahb" - DP controller memory region.
+			"dp_aux" - DP AUX memory region.
+			"dp_link" - DP link layer memory region.
+			"dp_p0" - DP pixel clock domain memory region.
+			"dp_phy" - DP PHY memory region.
+			"dp_ln_tx0" - USB3 DP PHY combo TX-0 lane memory region.
+			"dp_ln_tx1" - USB3 DP PHY combo TX-1 lane memory region.

Now there is more reason to separate the sub-module offsets like 
ahb/aux/link/p0
> Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
> ---
>  drivers/gpu/drm/msm/dp/dp_display.c |  1 +
>  drivers/gpu/drm/msm/dp/dp_parser.c  | 28 ++++++++++++++++++++--------
>  2 files changed, 21 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/gpu/drm/msm/dp/dp_display.c
> b/drivers/gpu/drm/msm/dp/dp_display.c
> index d1319b58e901..0be03bdc882c 100644
> --- a/drivers/gpu/drm/msm/dp/dp_display.c
> +++ b/drivers/gpu/drm/msm/dp/dp_display.c
> @@ -121,6 +121,7 @@ struct dp_display_private {
> 
>  static const struct of_device_id dp_dt_match[] = {
>  	{.compatible = "qcom,sc7180-dp"},
> +	{ .compatible = "qcom,sc8180x-edp" },
>  	{}
>  };
> 
> diff --git a/drivers/gpu/drm/msm/dp/dp_parser.c
> b/drivers/gpu/drm/msm/dp/dp_parser.c
> index 51ec85b4803b..47cf18bba4b2 100644
> --- a/drivers/gpu/drm/msm/dp/dp_parser.c
> +++ b/drivers/gpu/drm/msm/dp/dp_parser.c
> @@ -251,6 +251,7 @@ static int dp_parser_clock(struct dp_parser 
> *parser)
>  static int dp_parser_parse(struct dp_parser *parser)
>  {
>  	struct dss_io_data *io = &parser->io.dp_controller;
> +	struct device *dev = &parser->pdev->dev;
>  	int rc = 0;
> 
>  	if (!parser) {
> @@ -276,14 +277,25 @@ static int dp_parser_parse(struct dp_parser 
> *parser)
>  	 */
>  	parser->regulator_cfg = &sdm845_dp_reg_cfg;
> 
> -	io->ahb = io->base + 0x0;
> -	io->ahb_len = 0x200;
> -	io->aux = io->base + 0x200;
> -	io->aux_len = 0x200;
> -	io->link = io->base + 0x400;
> -	io->link_len = 0x600;
> -	io->p0 = io->base + 0x1000;
> -	io->p0_len = 0x400;
> +	if (of_device_is_compatible(dev->of_node, "qcom,sc8180x-edp")) {
> +		io->ahb = io->base + 0x0;
> +		io->ahb_len = 0x200;
> +		io->aux = io->base + 0x200;
> +		io->aux_len = 0x200;
> +		io->link = io->base + 0x400;
> +		io->link_len = 0x600;
> +		io->p0 = io->base + 0xa00;
> +		io->p0_len = 0x400;
> +	} else {
> +		io->ahb = io->base + 0x0;
> +		io->ahb_len = 0x200;
> +		io->aux = io->base + 0x200;
> +		io->aux_len = 0x200;
> +		io->link = io->base + 0x400;
> +		io->link_len = 0x600;
> +		io->p0 = io->base + 0x1000;
> +		io->p0_len = 0x400;
> +	}
> 
>  	return 0;
>  }