From mboxrd@z Thu Jan 1 00:00:00 1970 From: Derek Basehore Subject: [PATCH v7 1/4] drm/panel: Add helper for reading DT rotation Date: Tue, 9 Jul 2019 19:16:56 -0700 Message-ID: <20190710021659.177950-2-dbasehore@chromium.org> References: <20190710021659.177950-1-dbasehore@chromium.org> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <20190710021659.177950-1-dbasehore@chromium.org> Sender: linux-kernel-owner@vger.kernel.org To: linux-kernel@vger.kernel.org Cc: Maarten Lankhorst , Maxime Ripard , Sean Paul , David Airlie , Daniel Vetter , Thierry Reding , Sam Ravnborg , Jani Nikula , Joonas Lahtinen , Rodrigo Vivi , CK Hu , Philipp Zabel , Matthias Brugger , dri-devel@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org, Derek Basehore List-Id: linux-mediatek@lists.infradead.org This adds a helper function for reading the rotation (panel orientation) from the device tree. Signed-off-by: Derek Basehore --- drivers/gpu/drm/drm_panel.c | 43 +++++++++++++++++++++++++++++++++++++ include/drm/drm_panel.h | 9 ++++++++ 2 files changed, 52 insertions(+) diff --git a/drivers/gpu/drm/drm_panel.c b/drivers/gpu/drm/drm_panel.c index dbd5b873e8f2..169bab54d52d 100644 --- a/drivers/gpu/drm/drm_panel.c +++ b/drivers/gpu/drm/drm_panel.c @@ -172,6 +172,49 @@ struct drm_panel *of_drm_find_panel(const struct device_node *np) return ERR_PTR(-EPROBE_DEFER); } EXPORT_SYMBOL(of_drm_find_panel); + +/** + * of_drm_get_panel_orientation - look up the orientation of the panel through + * the "rotation" binding from a device tree node + * @np: device tree node of the panel + * @orientation: orientation enum to be filled in + * + * Looks up the rotation of a panel in the device tree. The orientation of the + * panel is expressed as a property name "rotation" in the device tree. The + * rotation in the device tree is counter clockwise. + * + * Return: 0 when a valid rotation value (0, 90, 180, or 270) is read or the + * rotation property doesn't exist. -EERROR otherwise. + */ +int of_drm_get_panel_orientation(const struct device_node *np, + enum drm_panel_orientation *orientation) +{ + int rotation, ret; + + ret = of_property_read_u32(np, "rotation", &rotation); + if (ret == -EINVAL) { + /* Don't return an error if there's no rotation property. */ + *orientation = DRM_MODE_PANEL_ORIENTATION_UNKNOWN; + return 0; + } + + if (ret < 0) + return ret; + + if (rotation == 0) + *orientation = DRM_MODE_PANEL_ORIENTATION_NORMAL; + else if (rotation == 90) + *orientation = DRM_MODE_PANEL_ORIENTATION_RIGHT_UP; + else if (rotation == 180) + *orientation = DRM_MODE_PANEL_ORIENTATION_BOTTOM_UP; + else if (rotation == 270) + *orientation = DRM_MODE_PANEL_ORIENTATION_LEFT_UP; + else + return -EINVAL; + + return 0; +} +EXPORT_SYMBOL(of_drm_get_panel_orientation); #endif MODULE_AUTHOR("Thierry Reding "); diff --git a/include/drm/drm_panel.h b/include/drm/drm_panel.h index 8c738c0e6e9f..fc7da55f41d9 100644 --- a/include/drm/drm_panel.h +++ b/include/drm/drm_panel.h @@ -33,6 +33,8 @@ struct drm_device; struct drm_panel; struct display_timing; +enum drm_panel_orientation; + /** * struct drm_panel_funcs - perform operations on a given panel * @disable: disable panel (turn off back light, etc.) @@ -197,11 +199,18 @@ int drm_panel_detach(struct drm_panel *panel); #if defined(CONFIG_OF) && defined(CONFIG_DRM_PANEL) struct drm_panel *of_drm_find_panel(const struct device_node *np); +int of_drm_get_panel_orientation(const struct device_node *np, + enum drm_panel_orientation *orientation); #else static inline struct drm_panel *of_drm_find_panel(const struct device_node *np) { return ERR_PTR(-ENODEV); } +static inline int of_drm_get_panel_orientation(const struct device_node *np, + enum drm_panel_orientation *orientation) +{ + return -ENODEV; +} #endif #endif -- 2.22.0.410.gd8fdbe21b5-goog