diff mbox series

[1/2] drivers: base: component: add function to query the bound status

Message ID 20250220234141.2788785-2-heiko@sntech.de (mailing list archive)
State New
Headers show
Series Fix the shutdown callback of a drm component device | expand

Commit Message

Heiko Stübner Feb. 20, 2025, 11:41 p.m. UTC
The component helpers already expose the bound status in debugfs, but at
times it might be necessary to also check that state in the kernel and
act differently depending on the result.

For example the shutdown handler of a drm-driver might need to stop
a whole output pipeline if the drm device is up and running, but may
run into problems if that drm-device has never been set up before,
for example because the binding deferred.

So add a little helper that returns the bound status for a componet
device.

Signed-off-by: Heiko Stuebner <heiko@sntech.de>
---
 drivers/base/component.c  | 14 ++++++++++++++
 include/linux/component.h |  4 +++-
 2 files changed, 17 insertions(+), 1 deletion(-)

Comments

Greg KH Feb. 21, 2025, 6:14 a.m. UTC | #1
On Fri, Feb 21, 2025 at 12:41:40AM +0100, Heiko Stuebner wrote:
> The component helpers already expose the bound status in debugfs, but at
> times it might be necessary to also check that state in the kernel and
> act differently depending on the result.
> 
> For example the shutdown handler of a drm-driver might need to stop
> a whole output pipeline if the drm device is up and running, but may
> run into problems if that drm-device has never been set up before,
> for example because the binding deferred.
> 
> So add a little helper that returns the bound status for a componet
> device.
> 
> Signed-off-by: Heiko Stuebner <heiko@sntech.de>
> ---
>  drivers/base/component.c  | 14 ++++++++++++++
>  include/linux/component.h |  4 +++-
>  2 files changed, 17 insertions(+), 1 deletion(-)

Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff mbox series

Patch

diff --git a/drivers/base/component.c b/drivers/base/component.c
index 741497324d78..d63e01f4851d 100644
--- a/drivers/base/component.c
+++ b/drivers/base/component.c
@@ -569,6 +569,20 @@  void component_master_del(struct device *parent,
 }
 EXPORT_SYMBOL_GPL(component_master_del);
 
+bool component_master_is_bound(struct device *parent,
+	const struct component_master_ops *ops)
+{
+	struct aggregate_device *adev;
+
+	guard(mutex)(&component_mutex);
+	adev = __aggregate_find(parent, ops);
+	if (!adev)
+		return 0;
+
+	return adev->bound;
+}
+EXPORT_SYMBOL_GPL(component_master_is_bound);
+
 static void component_unbind(struct component *component,
 	struct aggregate_device *adev, void *data)
 {
diff --git a/include/linux/component.h b/include/linux/component.h
index df4aa75c9e7c..9d6c66401280 100644
--- a/include/linux/component.h
+++ b/include/linux/component.h
@@ -3,7 +3,7 @@ 
 #define COMPONENT_H
 
 #include <linux/stddef.h>
-
+#include <linux/types.h>
 
 struct device;
 
@@ -90,6 +90,8 @@  int component_compare_dev_name(struct device *dev, void *data);
 
 void component_master_del(struct device *,
 	const struct component_master_ops *);
+bool component_master_is_bound(struct device *parent,
+	const struct component_master_ops *ops);
 
 struct component_match;