[PATCH 1/2] amba: Add dev_is_amba() function and export it for modules

[Kunwu Chan]

Add dev_is_amba() function to determine
whether the device is a AMBA device.

Suggested-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Signed-off-by: Kunwu Chan <chentao@xxxxxxxxxx>
---
 drivers/amba/bus.c       | 6 ++++++
 include/linux/amba/bus.h | 5 +++++
 2 files changed, 11 insertions(+)

diff --git a/drivers/amba/bus.c b/drivers/amba/bus.c
index 0230c43377c1..8ef259b4d037 100644
--- a/drivers/amba/bus.c
+++ b/drivers/amba/bus.c
@@ -449,6 +449,12 @@ const struct bus_type amba_bustype = {
 };
 EXPORT_SYMBOL_GPL(amba_bustype);
 
+bool dev_is_amba(const struct device *dev)
+{
+	return dev->bus == &amba_bustype;
+}
+EXPORT_SYMBOL_GPL(dev_is_amba);
+
 static int __init amba_init(void)
 {
 	return bus_register(&amba_bustype);
diff --git a/include/linux/amba/bus.h b/include/linux/amba/bus.h
index dda2f3ea89cb..9946276aff73 100644
--- a/include/linux/amba/bus.h
+++ b/include/linux/amba/bus.h
@@ -121,6 +121,7 @@ extern const struct bus_type amba_bustype;
 #ifdef CONFIG_ARM_AMBA
 int __amba_driver_register(struct amba_driver *, struct module *);
 void amba_driver_unregister(struct amba_driver *);
+bool dev_is_amba(const struct device *dev);
 #else
 static inline int __amba_driver_register(struct amba_driver *drv,
 					 struct module *owner)
@@ -130,6 +131,10 @@ static inline int __amba_driver_register(struct amba_driver *drv,
 static inline void amba_driver_unregister(struct amba_driver *drv)
 {
 }
+static inline bool dev_is_amba(const struct device *dev)
+{
+	return false;
+}
 #endif
 
 struct amba_device *amba_device_alloc(const char *, resource_size_t, size_t);
-- 
2.43.0