ipa: Add start() and stop() operations

Add two new operations to the IPA interface to start and stop it. The
intention is that these functions shall be used by the IPA to perform
actions when the camera is started and stopped.

Signed-off-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

include/ipa/ipa_interface.h

@@ -64,6 +64,8 @@ struct ipa_context_ops {
 	void (*destroy)(struct ipa_context *ctx);
 	void *(*get_interface)(struct ipa_context *ctx);
 	void (*init)(struct ipa_context *ctx);
+	int (*start)(struct ipa_context *ctx);
+	void (*stop)(struct ipa_context *ctx);
 	void (*register_callbacks)(struct ipa_context *ctx,
 				   const struct ipa_callback_ops *callbacks,
 				   void *cb_ctx);
@@ -120,6 +122,8 @@ public:
 	virtual ~IPAInterface() {}
 
 	virtual int init() = 0;
+	virtual int start() = 0;
+	virtual void stop() = 0;
 
 	virtual void configure(const std::map<unsigned int, IPAStream> &streamConfig,
 			       const std::map<unsigned int, const ControlInfoMap &> &entityControls) = 0;

include/ipa/ipa_vimc.h

@@ -15,6 +15,8 @@ namespace libcamera {
 enum IPAOperationCode {
 	IPAOperationNone,
 	IPAOperationInit,
+	IPAOperationStart,
+	IPAOperationStop,
 };
 
 } /* namespace libcamera */