linux-mediatek.lists.infradead.org archive mirror
 help / color / mirror / Atom feed
From: CK Hu <ck.hu@mediatek.com>
To: Markus Schneider-Pargmann <msp@baylibre.com>
Cc: Chun-Kuang Hu <chunkuang.hu@kernel.org>,
	Philipp Zabel <p.zabel@pengutronix.de>,
	<dri-devel@lists.freedesktop.org>,
	<linux-mediatek@lists.infradead.org>,
	<linux-arm-kernel@lists.infradead.org>
Subject: Re: [RFC PATCH 2/5] drm/mediatek: dpi: Add dpintf support
Date: Tue, 17 Aug 2021 17:50:44 +0800	[thread overview]
Message-ID: <1629193844.19746.2.camel@mtksdaap41> (raw)
In-Reply-To: <20210816192523.1739365-3-msp@baylibre.com>

Hi, Markus:

On Mon, 2021-08-16 at 21:25 +0200, Markus Schneider-Pargmann wrote:
> dpintf is the displayport interface hardware unit. This unit is similar
> to dpi and can reuse most of the code.
> 
> This patch adds support for mt8195-dpintf to this dpi driver. Main
> differences are:
>  - Some features/functional components are not available for dpintf
>    which are now excluded from code execution once is_dpintf is set
>  - dpintf can and needs to choose between different clockdividers based
>    on the clockspeed. This is done by choosing a different clock parent.
>  - There are two additional clocks that need to be managed. These are
>    only set for dpintf and will be set to NULL if not supplied. The
>    clk_* calls handle these as normal clocks then.
>  - Some register contents differ slightly between the two components. To
>    work around this I added register bits/masks with a DPINTF_ prefix
>    and use them where different.
> 
> Based on a separate driver for dpintf created by
> Jason-JH.Lin <jason-jh.lin@mediatek.com>.
> 
> Signed-off-by: Markus Schneider-Pargmann <msp@baylibre.com>
> ---
>  drivers/gpu/drm/mediatek/mtk_dpi.c      | 282 ++++++++++++++++++++----
>  drivers/gpu/drm/mediatek/mtk_dpi_regs.h |  12 +
>  2 files changed, 247 insertions(+), 47 deletions(-)
> 

[snip]

>  
> +static void mtk_dpi_set_pixel_clk_parent(struct mtk_dpi *dpi,
> +					 unsigned int factor)
> +{
> +	struct clk *new_parent;
> +
> +	switch (factor) {
> +	case 16:
> +		new_parent = dpi->tvd_clks[MTK_DPI_TVDPLL_D16].clk;
> +		break;
> +	case 8:
> +		new_parent = dpi->tvd_clks[MTK_DPI_TVDPLL_D8].clk;
> +		break;
> +	case 4:
> +		new_parent = dpi->tvd_clks[MTK_DPI_TVDPLL_D4].clk;
> +		break;
> +	case 2:
> +		new_parent = dpi->tvd_clks[MTK_DPI_TVDPLL_D2].clk;
> +		break;
> +	default:
> +		new_parent = NULL;
> +	}
> +	if (new_parent)
> +		clk_set_parent(dpi->pixel_clk, new_parent);

I prefer that dpi->pixel_clk provide set_rate() interface, and let clock
driver to control the parent of dpi->pixel_clk.

Regards,
CK

> +}
> +
>  static int mtk_dpi_set_display_mode(struct mtk_dpi *dpi,
>  				    struct drm_display_mode *mode)
>  {
> @@ -465,6 +568,8 @@ static int mtk_dpi_set_display_mode(struct mtk_dpi *dpi,
>  	drm_display_mode_to_videomode(mode, &vm);
>  	pll_rate = vm.pixelclock * factor;
>  
> +	mtk_dpi_set_pixel_clk_parent(dpi, factor);
> +
>  	dev_dbg(dpi->dev, "Want PLL %lu Hz, pixel clock %lu Hz\n",
>  		pll_rate, vm.pixelclock);
>  


_______________________________________________
Linux-mediatek mailing list
Linux-mediatek@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-mediatek

  reply	other threads:[~2021-08-17  9:51 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-16 19:25 [RFC PATCH 0/5] drm/mediatek: Add mt8195 DisplayPort driver Markus Schneider-Pargmann
2021-08-16 19:25 ` [RFC PATCH 1/5] dt-bindings: mediatek,dpi: Add mt8195 dpintf Markus Schneider-Pargmann
2021-08-18  4:45   ` CK Hu
2021-08-18  7:30     ` Markus Schneider-Pargmann
2021-08-16 19:25 ` [RFC PATCH 2/5] drm/mediatek: dpi: Add dpintf support Markus Schneider-Pargmann
2021-08-17  9:50   ` CK Hu [this message]
2021-08-18  7:26     ` Markus Schneider-Pargmann
2021-08-16 19:25 ` [RFC PATCH 3/5] drm/edid: Add cea_sad helpers for freq/length Markus Schneider-Pargmann
2021-08-16 19:25 ` [RFC PATCH 4/5] video/hdmi: Add audio_infoframe packing for DP Markus Schneider-Pargmann
2021-08-16 19:25 ` [RFC PATCH 5/5] drm/mediatek: Add mt8195 DisplayPort driver Markus Schneider-Pargmann
2021-08-16 21:36   ` Sam Ravnborg
2021-08-17  7:31     ` Markus Schneider-Pargmann
2021-08-17  5:36   ` CK Hu
2021-08-17  7:35     ` Markus Schneider-Pargmann
2021-08-18  4:42   ` CK Hu

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1629193844.19746.2.camel@mtksdaap41 \
    --to=ck.hu@mediatek.com \
    --cc=chunkuang.hu@kernel.org \
    --cc=dri-devel@lists.freedesktop.org \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-mediatek@lists.infradead.org \
    --cc=msp@baylibre.com \
    --cc=p.zabel@pengutronix.de \
    --subject='Re: [RFC PATCH 2/5] drm/mediatek: dpi: Add dpintf support' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).