Re: [PATCH v4 02/12] drm: bridge: Add Samsung DSIM bridge driver

From: Jagan Teki <jagan@amarulasolutions.com>
To: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Andrzej Hajda <andrzej.hajda@intel.com>,
	Inki Dae <inki.dae@samsung.com>,
	Joonyoung Shim <jy0922.shim@samsung.com>,
	Seung-Woo Kim <sw0312.kim@samsung.com>,
	Kyungmin Park <kyungmin.park@samsung.com>,
	Frieder Schrempf <frieder.schrempf@kontron.de>,
	Fancy Fang <chen.fang@nxp.com>,
	Tim Harvey <tharvey@gateworks.com>,
	Michael Nazzareno Trimarchi <michael@amarulasolutions.com>,
	Adam Ford <aford173@gmail.com>,
	Neil Armstrong <narmstrong@baylibre.com>,
	Robert Foss <robert.foss@linaro.org>,
	Laurent Pinchart <Laurent.pinchart@ideasonboard.com>,
	Tommaso Merciai <tommaso.merciai@amarulasolutions.com>,
	Marek Vasut <marex@denx.de>,
	linux-samsung-soc@vger.kernel.org,
	Matteo Lisi <matteo.lisi@engicam.com>,
	dri-devel@lists.freedesktop.org,
	NXP Linux Team <linux-imx@nxp.com>,
	linux-amarula <linux-amarula@amarulasolutions.com>,
	linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v4 02/12] drm: bridge: Add Samsung DSIM bridge driver
Date: Wed, 7 Sep 2022 00:37:16 +0530	[thread overview]
Message-ID: <CAMty3ZBVrRa9VHDpGBM_r9gdU=Ex4iwpSHjzcOdxSBrwRrHF2A@mail.gmail.com> (raw)
In-Reply-To: <d750a140-c87e-16af-7683-22d48f68305a@samsung.com>

On Mon, Sep 5, 2022 at 4:54 PM Marek Szyprowski
<m.szyprowski@samsung.com> wrote:
>
> Hi All,
>
> On 02.09.2022 12:47, Marek Szyprowski wrote:
> > On 29.08.2022 20:40, Jagan Teki wrote:
> >> Samsung MIPI DSIM controller is common DSI IP that can be used in
> >> various
> >> SoCs like Exynos, i.MX8M Mini/Nano.
> >>
> >> In order to access this DSI controller between various platform SoCs,
> >> the ideal way to incorporate this in the drm stack is via the drm bridge
> >> driver.
> >>
> >> This patch is trying to differentiate platform-specific and bridge
> >> driver
> >> code and keep maintaining the exynos_drm_dsi.c code as platform-specific
> >> glue code and samsung-dsim.c as a common bridge driver code.
> >>
> >> - Exynos specific glue code is exynos specific te_irq, host_attach, and
> >>    detach code along with conventional component_ops.
> >>
> >> - Samsung DSIM is a bridge driver which is common across all
> >> platforms and
> >>    the respective platform-specific glue will initialize at the end
> >> of the
> >>    probe. The platform-specific operations and other glue calls will
> >> invoke
> >>    on associate code areas.
> >>
> >> v4:
> >> * include Inki Dae in MAINTAINERS
> >> * remove dsi_driver probe in exynos_drm_drv to support multi-arch build
> >
> > This breaks Exynos DRM completely as the Exynos DRM driver is not able
> > to wait until the DSI driver is probed and registered as component.
> >
> > I will show how to rework this the way it is done in
> > drivers/gpu/drm/exynos/exynos_dp.c and
> > drivers/gpu/drm/bridge/analogix/analogix_dp_core.c soon...
>
> I've finally had some time to implement such approach, see
> https://github.com/mszyprow/linux/tree/v6.0-dsi-v4-reworked
>
> If you want me to send the patches against your v4 patchset, let me
> know, but imho my changes are much more readable after squashing to the
> original patches.
>
> Now the driver is fully multi-arch safe and ready for further
> extensions. I've removed the weak functions, reworked the way the
> plat_data is used (dropped the patch related to it) and restored
> exynos-dsi driver as a part of the Exynos DRM drivers/subsystem. Feel
> free to resend the above as v5 after testing on your hardware. At least
> it properly works now on all Exynos boards I have, both compiled into
> the kernel or as modules.

Thanks. I've seen the repo added on top of Dave patches - does it mean
these depends on Dave changes as well?

Jagan.