From: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
To: Maxime Ripard <maxime.ripard@bootlin.com>
Cc: Mark Rutland <mark.rutland@arm.com>,
devicetree@vger.kernel.org, David Airlie <airlied@linux.ie>,
linux-sunxi@googlegroups.com, linux-kernel@vger.kernel.org,
dri-devel@lists.freedesktop.org,
Andrzej Hajda <a.hajda@samsung.com>, Chen-Yu Tsai <wens@csie.org>,
Rob Herring <robh+dt@kernel.org>,
jagan@amarulasolutions.com, Daniel Vetter <daniel@ffwll.ch>,
Michael Trimarchi <michael@amarulasolutions.com>,
linux-amarula@amarulasolutions.com,
linux-arm-kernel@lists.infradead.org,
Laurent Pinchart <Laurent.pinchart@ideasonboard.com>
Subject: Re: [linux-sunxi] [PATCH 3/6] drm/sun4i: dsi: Add bridge support
Date: Fri, 15 Mar 2019 14:48:07 +0100 [thread overview]
Message-ID: <3206b448f031ce22acc2db979781f19c1dded20c.camel@bootlin.com> (raw)
In-Reply-To: <20190315134555.ekpywymjx3xqmdhf@flea>
Hi,
On Fri, 2019-03-15 at 14:45 +0100, Maxime Ripard wrote:
> On Fri, Mar 15, 2019 at 02:32:55PM +0100, Paul Kocialkowski wrote:
> > Hi,
> >
> > On Fri, 2019-03-15 at 18:38 +0530, Jagan Teki wrote:
> > > Some display panels would come up with a non-DSI output which
> > > can have an option to connect DSI interface by means of bridge
> > > convertor.
> > >
> > > This DSI to non-DSI bridge convertor would require a bridge
> > > driver that would communicate the DSI controller for bridge
> > > functionalities.
> > >
> > > So, add support for bridge functionalities in Allwinner DSI
> > > controller.
> >
> > See a few comments below.
> >
> > > Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
> > > ---
> > > drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c | 65 +++++++++++++++++++-------
> > > drivers/gpu/drm/sun4i/sun6i_mipi_dsi.h | 1 +
> > > 2 files changed, 49 insertions(+), 17 deletions(-)
> > >
> > > diff --git a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
> > > index 0960b96b62cc..64d74313b842 100644
> > > --- a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
> > > +++ b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
> > > @@ -781,6 +781,9 @@ static void sun6i_dsi_encoder_enable(struct drm_encoder *encoder)
> > > if (!IS_ERR(dsi->panel))
> > > drm_panel_prepare(dsi->panel);
> > >
> > > + if (!IS_ERR(dsi->bridge))
> > > + drm_bridge_pre_enable(dsi->bridge);
> > > +
> > > /*
> > > * FIXME: This should be moved after the switch to HS mode.
> > > *
> > > @@ -796,6 +799,9 @@ static void sun6i_dsi_encoder_enable(struct drm_encoder *encoder)
> > > if (!IS_ERR(dsi->panel))
> > > drm_panel_enable(dsi->panel);
> > >
> > > + if (!IS_ERR(dsi->bridge))
> > > + drm_bridge_enable(dsi->bridge);
> > > +
> > > sun6i_dsi_start(dsi, DSI_START_HSC);
> > >
> > > udelay(1000);
> > > @@ -812,6 +818,9 @@ static void sun6i_dsi_encoder_disable(struct drm_encoder *encoder)
> > > if (!IS_ERR(dsi->panel)) {
> > > drm_panel_disable(dsi->panel);
> > > drm_panel_unprepare(dsi->panel);
> > > + } else if (!IS_ERR(dsi->bridge)) {
> > > + drm_bridge_disable(dsi->bridge);
> > > + drm_bridge_post_disable(dsi->bridge);
> > > }
> > >
> > > phy_power_off(dsi->dphy);
> > > @@ -973,11 +982,16 @@ static int sun6i_dsi_attach(struct mipi_dsi_host *host,
> > > struct sun6i_dsi *dsi = host_to_sun6i_dsi(host);
> > >
> > > dsi->device = device;
> > > - dsi->panel = of_drm_find_panel(device->dev.of_node);
> > > - if (IS_ERR(dsi->panel))
> > > - return PTR_ERR(dsi->panel);
> > >
> > > - dev_info(host->dev, "Attached device %s\n", device->name);
> > > + dsi->bridge = of_drm_find_bridge(device->dev.of_node);
> > > + if (!dsi->bridge) {
> >
> > You are using IS_ERR to check that the bridge is alive in the changes
> > above, but switch to checking that it's non-NULL at this point.
> >
> > Are both guaranteed to be interchangeable?
>
> They aren't. Any ERR_PTR will be !NULL
>
> > > + dsi->panel = of_drm_find_panel(device->dev.of_node);
> > > + if (IS_ERR(dsi->panel))
> > > + return PTR_ERR(dsi->panel);
> > > + }
> >
> > You should probably use drm_of_find_panel_or_bridge instead of
> > duplicating the logic here.
>
> Or we can even use the drm_panel_bridge_add to simplify things.
Indeed, I was just looking at that and it seems to be specifically
tailored for this use case.
Cheers,
Paul
--
Paul Kocialkowski, Bootlin
Embedded Linux and kernel engineering
https://bootlin.com
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next prev parent reply other threads:[~2019-03-15 13:48 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-15 13:08 [PATCH 0/6] drm/bridge: Add ICN6211 MIPI-DSI/RGB bridge Jagan Teki
2019-03-15 13:08 ` [PATCH 1/6] drm/bridge: Export drm_bridge_detach Jagan Teki
2019-03-15 13:27 ` [linux-sunxi] " Paul Kocialkowski
2019-03-18 16:48 ` Jagan Teki
2019-03-18 16:57 ` Paul Kocialkowski
2019-03-18 17:07 ` Jagan Teki
2019-03-15 13:08 ` [PATCH 2/6] drm/exynos: dsi: Use drm_bridge_detach Jagan Teki
2019-03-19 3:59 ` Inki Dae
2019-03-15 13:08 ` [PATCH 3/6] drm/sun4i: dsi: Add bridge support Jagan Teki
2019-03-15 13:32 ` [linux-sunxi] " Paul Kocialkowski
2019-03-15 13:45 ` Maxime Ripard
2019-03-15 13:48 ` Paul Kocialkowski [this message]
2019-05-22 12:01 ` Jagan Teki
2019-03-15 13:08 ` [PATCH 4/6] dt-bindings: display: bridge: Add ICN6211 MIPI-DSI to RGB convertor bridge Jagan Teki
2019-03-15 13:34 ` Maxime Ripard
2019-03-18 16:58 ` Jagan Teki
2019-03-19 2:59 ` [linux-sunxi] " Chen-Yu Tsai
2019-03-19 7:48 ` Jagan Teki
2019-03-19 8:35 ` Maxime Ripard
2019-03-15 13:08 ` [PATCH 5/6] drm/bridge: Add Chipone ICN6211 MIPI-DSI/RGB " Jagan Teki
2019-03-15 13:33 ` Maxime Ripard
2019-03-17 16:30 ` Laurent Pinchart
2019-03-18 17:59 ` Jagan Teki
2019-03-19 3:05 ` [linux-sunxi] " Chen-Yu Tsai
2019-03-15 13:08 ` [PATCH 6/6] arm64: dts: allwinner: bananapi-m64: Enable S070WV20-CT16 DSI panel Jagan Teki
2019-03-15 13:25 ` Maxime Ripard
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