ipa: vimc: Add support for tracing operations

Add support to the dummy VIMC IPA for tracing operation by using a FIFO
channel that will be used by the IPA Interface test to verify
communications with the IPA.

At the moment only add support for the init() operation as it's the only
defined one.

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Jacopo Mondi <jacopo@jmondi.org>

src/ipa/ipa_vimc.cpp

@@ -5,25 +5,91 @@
  * ipa_vimc.cpp - Vimc Image Processing Algorithm module
  */
 
+#include <ipa/ipa_vimc.h>
+
+#include <fcntl.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
 #include <iostream>
 
 #include <ipa/ipa_interface.h>
 #include <ipa/ipa_module_info.h>
 
+#include "log.h"
+
 namespace libcamera {
 
+LOG_DEFINE_CATEGORY(IPAVimc)
+
 class IPAVimc : public IPAInterface
 {
 public:
+	IPAVimc();
+	~IPAVimc();
+
 	int init();
+
+private:
+	void initTrace();
+	void trace(enum IPAOperationCode operation);
+
+	int fd_;
 };
 
+IPAVimc::IPAVimc()
+	: fd_(-1)
+{
+	initTrace();
+}
+
+IPAVimc::~IPAVimc()
+{
+	if (fd_)
+		::close(fd_);
+}
+
 int IPAVimc::init()
 {
-	std::cout << "initializing vimc IPA!" << std::endl;
+	trace(IPAOperationInit);
+
+	LOG(IPAVimc, Debug) << "initializing vimc IPA!";
+
 	return 0;
 }
 
+void IPAVimc::initTrace()
+{
+	struct stat fifoStat;
+	int ret = stat(VIMC_IPA_FIFO_PATH, &fifoStat);
+	if (ret)
+		return;
+
+	ret = ::open(VIMC_IPA_FIFO_PATH, O_WRONLY);
+	if (ret < 0) {
+		ret = errno;
+		LOG(IPAVimc, Error) << "Failed to open vimc IPA test FIFO: "
+				    << strerror(ret);
+		return;
+	}
+
+	fd_ = ret;
+}
+
+void IPAVimc::trace(enum IPAOperationCode operation)
+{
+	if (fd_ < 0)
+		return;
+
+	int ret = ::write(fd_, &operation, sizeof(operation));
+	if (ret < 0) {
+		ret = errno;
+		LOG(IPAVimc, Error) << "Failed to write to vimc IPA test FIFO: "
+				    << strerror(ret);
+	}
+}
+
 /*
  * External IPA module interface
  */