[PATCH 33/34] drm/bridge: add devm_drm_put_bridge()

[Luca Ceresoli]

Bridges obtained via devm_drm_bridge_alloc(dev, ...) will be put when the
requesting device (@dev) is removed.

However drivers which obtained them may need to put the obtained reference
explicitly. One such case is if they bind the devm removal action to a
different device than the one implemented by the driver itself and which
might be removed at a different time, such as bridge/panel.c.

Add devm_drm_put_bridge() to manually release a devm-obtained bridge in
such cases.

Signed-off-by: Luca Ceresoli <luca.ceresoli at bootlin.com>
---

To: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
To: Maxime Ripard <mripard at kernel.org>
To: Thomas Zimmermann <tzimmermann at suse.de>
To: David Airlie <airlied at gmail.com>
To: Simona Vetter <simona at ffwll.ch>
To: Andrzej Hajda <andrzej.hajda at intel.com>
To: Neil Armstrong <neil.armstrong at linaro.org>
To: Robert Foss <rfoss at kernel.org>
To: Laurent Pinchart <Laurent.pinchart at ideasonboard.com>
To: Jonas Karlman <jonas at kwiboo.se>
To: Jernej Skrabec <jernej.skrabec at gmail.com>
To: Jagan Teki <jagan at amarulasolutions.com>
To: Shawn Guo <shawnguo at kernel.org>
To: Sascha Hauer <s.hauer at pengutronix.de>
To: Pengutronix Kernel Team <kernel at pengutronix.de>
To: Fabio Estevam <festevam at gmail.com>
To: Douglas Anderson <dianders at chromium.org>
To: Chun-Kuang Hu <chunkuang.hu at kernel.org>
To: Krzysztof Kozlowski <krzk at kernel.org>
To: Dmitry Baryshkov <dmitry.baryshkov at linaro.org>
Cc: Anusha Srivatsa <asrivats at redhat.com>
Cc: Paul Kocialkowski <paulk at sys-base.io>
Cc: Dmitry Baryshkov <lumag at kernel.org>
Cc: Hervé Codina <herve.codina at bootlin.com>
Cc: Hui Pu <Hui.Pu at gehealthcare.com>
Cc: Thomas Petazzoni <thomas.petazzoni at bootlin.com>
Cc: dri-devel at lists.freedesktop.org
Cc: asahi at lists.linux.dev
Cc: linux-kernel at vger.kernel.org
Cc: chrome-platform at lists.linux.dev
Cc: imx at lists.linux.dev
Cc: linux-arm-kernel at lists.infradead.org
Cc: linux-mediatek at lists.infradead.org
Cc: linux-amlogic at lists.infradead.org
Cc: linux-renesas-soc at vger.kernel.org
Cc: platform-driver-x86 at vger.kernel.org
Cc: linux-samsung-soc at vger.kernel.org
Cc: linux-arm-msm at vger.kernel.org
Cc: freedreno at lists.freedesktop.org
Cc: linux-stm32 at st-md-mailman.stormreply.com
---
 drivers/gpu/drm/drm_bridge.c | 14 ++++++++++++++
 include/drm/drm_bridge.h     |  4 ++++
 2 files changed, 18 insertions(+)

diff --git a/drivers/gpu/drm/drm_bridge.c b/drivers/gpu/drm/drm_bridge.c
index b4c89ec01998b849018ce031c7cd84614e65e710..456363d86080b2a55035c3108c16afa4f9e57e06 100644
--- a/drivers/gpu/drm/drm_bridge.c
+++ b/drivers/gpu/drm/drm_bridge.c
@@ -1392,6 +1392,20 @@ struct drm_bridge *of_drm_find_bridge(struct device_node *np)
 EXPORT_SYMBOL(of_drm_find_bridge);
 #endif
 
+/**
+ * devm_drm_put_bridge - Release a bridge reference obtained via devm
+ * @dev: device that got the bridge via devm
+ * @bridge: pointer to a struct drm_bridge obtained via devm
+ *
+ * Same as drm_bridge_put() for bridge pointers obtained via devm functions
+ * such as devm_drm_bridge_alloc().
+ */
+void devm_drm_put_bridge(struct device *dev, struct drm_bridge *bridge)
+{
+	devm_release_action(dev, drm_bridge_put_void, bridge);
+}
+EXPORT_SYMBOL(devm_drm_put_bridge);
+
 static void drm_bridge_debugfs_show_bridge(struct drm_printer *p,
 					   struct drm_bridge *bridge,
 					   unsigned int idx)
diff --git a/include/drm/drm_bridge.h b/include/drm/drm_bridge.h
index df9bbf6fd1fb522add28b76406b74cdb7391fc57..5b4e5e935a17ba6fc4a6a53ad0a302e249ca418b 100644
--- a/include/drm/drm_bridge.h
+++ b/include/drm/drm_bridge.h
@@ -1167,6 +1167,8 @@ static inline struct drm_bridge *devm_drm_of_get_bridge(struct device *dev,
 	return ERR_PTR(-ENODEV);
 }
 
+static inline void devm_drm_put_bridge(struct device *dev, struct drm_bridge *bridge) {}
+
 static inline struct drm_bridge *drmm_of_get_bridge(struct drm_device *drm,
 						     struct device_node *node,
 						     u32 port,
@@ -1176,6 +1178,8 @@ static inline struct drm_bridge *drmm_of_get_bridge(struct drm_device *drm,
 }
 #endif
 
+void devm_drm_put_bridge(struct device *dev, struct drm_bridge *bridge);
+
 void drm_bridge_debugfs_params(struct dentry *root);
 void drm_bridge_debugfs_encoder_params(struct dentry *root, struct drm_encoder *encoder);
 

-- 
2.49.0