From mboxrd@z Thu Jan 1 00:00:00 1970 From: Maxime Ripard Subject: Re: [PATCH 3/6] drm/sun4i: dsi: Add bridge support Date: Fri, 15 Mar 2019 14:45:55 +0100 Message-ID: <20190315134555.ekpywymjx3xqmdhf@flea> References: <20190315130825.9005-1-jagan@amarulasolutions.com> <20190315130825.9005-4-jagan@amarulasolutions.com> Reply-To: maxime.ripard-LDxbnhwyfcJBDgjK7y7TUQ@public.gmane.org Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="pswiqfcemuf43jfz" Return-path: Sender: linux-sunxi-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org Content-Disposition: inline In-Reply-To: List-Post: , List-Help: , List-Archive: , List-Unsubscribe: , To: Paul Kocialkowski Cc: jagan-dyjBcgdgk7Pe9wHmmfpqLFaTQe2KTcn/@public.gmane.org, Andrzej Hajda , Laurent Pinchart , Chen-Yu Tsai , David Airlie , Daniel Vetter , Rob Herring , Mark Rutland , Michael Trimarchi , dri-devel-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, linux-sunxi-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org, linux-amarula-dyjBcgdgk7Pe9wHmmfpqLFaTQe2KTcn/@public.gmane.org List-Id: dri-devel@lists.freedesktop.org --pswiqfcemuf43jfz Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline 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 > > --- > > 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. Maxime -- Maxime Ripard, Bootlin Embedded Linux and Kernel engineering https://bootlin.com --pswiqfcemuf43jfz--