From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751562AbdBFKS4 (ORCPT ); Mon, 6 Feb 2017 05:18:56 -0500 Received: from foss.arm.com ([217.140.101.70]:54530 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751115AbdBFKSy (ORCPT ); Mon, 6 Feb 2017 05:18:54 -0500 Date: Mon, 6 Feb 2017 10:18:51 +0000 From: Liviu Dudau To: Rob Herring Cc: David Airlie , Daniel Vetter , Sean Paul , dri-devel@lists.freedesktop.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, Frank Rowand , Boris Brezillon , Archit Taneja , Jingoo Han , Inki Dae , Joonyoung Shim , Seung-Woo Kim , Kyungmin Park , Kukjin Kim , Krzysztof Kozlowski , Javier Martinez Canillas , Stefan Agner , Alison Wang , Xinliang Liu , Rongrong Zou , Xinwei Kong , Chen Feng , Philipp Zabel , CK Hu , Matthias Brugger , Marek Vasut , Mark Yao , Heiko Stuebner , Maxime Ripard , Chen-Yu Tsai , Mali DP Maintainers , Neil Armstrong , Carlo Caione , Kevin Hilman , Rob Clark , Jyri Sarha , Tomi Valkeinen , Eric Anholt , Russell King Subject: Re: [PATCH 2/5] drm: of: introduce drm_of_find_panel_or_bridge Message-ID: <20170206101851.GU3140@e110455-lin.cambridge.arm.com> References: <20170204033635.10250-1-robh@kernel.org> <20170204033635.10250-3-robh@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20170204033635.10250-3-robh@kernel.org> User-Agent: Mutt/1.7.2 (2016-11-26) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Feb 03, 2017 at 09:36:32PM -0600, Rob Herring wrote: > Many drivers have a common pattern of searching the OF graph for either an > attached panel or bridge and then finding the DRM struct for the panel > or bridge. Also, most drivers need to handle deferred probing when the > DRM device is not yet instantiated. Create a common function, > drm_of_find_panel_or_bridge, to find the connected node and the > associated DRM panel or bridge device. > > Signed-off-by: Rob Herring > --- > drivers/gpu/drm/drm_of.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++++ > include/drm/drm_of.h | 13 +++++++++++++ > 2 files changed, 63 insertions(+) > > diff --git a/drivers/gpu/drm/drm_of.c b/drivers/gpu/drm/drm_of.c > index 47848ed8ca48..b29ce2f52113 100644 > --- a/drivers/gpu/drm/drm_of.c > +++ b/drivers/gpu/drm/drm_of.c > @@ -3,7 +3,9 @@ > #include > #include > #include > +#include > #include > +#include > #include > > static void drm_release_of(struct device *dev, void *data) > @@ -207,3 +209,51 @@ int drm_of_encoder_active_endpoint(struct device_node *node, > return -EINVAL; > } > EXPORT_SYMBOL_GPL(drm_of_encoder_active_endpoint); > + > +/* > + * drm_of_find_panel_or_bridge - return connected panel or bridge device > + * @np: device tree node containing encoder input ports > + * @panel: pointer to hold returned drm_panel > + * @bridge: pointer to hold returned drm_bridge > + * > + * Given a DT node's port and endpoint number, find the connected node and > + * return either the associated struct drm_panel or drm_bridge device. > + * > + * Returns zero if successful, or one of the standard error codes if it fails. > + */ > +int drm_of_find_panel_or_bridge(const struct device_node *np, > + int port, int endpoint, > + struct drm_panel **panel, > + struct drm_bridge **bridge) > +{ > + int ret = -ENODEV; Given that you never return 'ret' with -ENODEV can I suggest that you initialise 'ret' with -EPROBE_DEFER and then you can get rid of the two assignments further down? Otherwise, looks good to me. Best regards, Liviu > + struct device_node *remote; > + > + remote = of_graph_get_remote_node(np, port, endpoint); > + if (!remote) > + return -ENODEV; > + > + if (bridge) > + *bridge = NULL; > + > + if (panel) { > + *panel = of_drm_find_panel(remote); > + if (*panel) { > + ret = 0; > + goto out_put; > + } > + ret = -EPROBE_DEFER; > + } > + > + if (bridge) { > + *bridge = of_drm_find_bridge(remote); > + if (*bridge) > + ret = 0; > + else > + ret = -EPROBE_DEFER; > + } > +out_put: > + of_node_put(remote); > + return ret; > +} > +EXPORT_SYMBOL_GPL(drm_of_find_panel_or_bridge); > diff --git a/include/drm/drm_of.h b/include/drm/drm_of.h > index 26a64805cc15..f86507f0599b 100644 > --- a/include/drm/drm_of.h > +++ b/include/drm/drm_of.h > @@ -8,6 +8,8 @@ struct component_match; > struct device; > struct drm_device; > struct drm_encoder; > +struct drm_panel; > +struct drm_bridge; > struct device_node; > > #ifdef CONFIG_OF > @@ -23,6 +25,10 @@ extern int drm_of_component_probe(struct device *dev, > extern int drm_of_encoder_active_endpoint(struct device_node *node, > struct drm_encoder *encoder, > struct of_endpoint *endpoint); > +extern int drm_of_find_panel_or_bridge(const struct device_node *np, > + int port, int endpoint, > + struct drm_panel **panel, > + struct drm_bridge **bridge); > #else > static inline uint32_t drm_of_find_possible_crtcs(struct drm_device *dev, > struct device_node *port) > @@ -52,6 +58,13 @@ static inline int drm_of_encoder_active_endpoint(struct device_node *node, > { > return -EINVAL; > } > +static inline int drm_of_find_panel_or_bridge(const struct device_node *np, > + int port, int endpoint, > + struct drm_panel **panel, > + struct drm_bridge **bridge) > +{ > + return -EINVAL; > +} > #endif > > static inline int drm_of_encoder_active_endpoint_id(struct device_node *node, > -- > 2.10.1 > -- ==================== | I would like to | | fix the world, | | but they're not | | giving me the | \ source code! / --------------- ¯\_(ツ)_/¯