From f23e6127ad073a99d4374929f95aac9d3f24dba8 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Niklas=20S=C3=B6derlund?= <niklas.soderlund@ragnatech.se>
Date: Wed, 15 Jul 2020 17:31:46 +0200
Subject: libcamera: camera_sensor: Generate a sensor ID
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The ID is generated from information in the firmware description of the
sensor if available or from module and model information if the sensor
is virtual (for example VIMC).

Signed-off-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
 src/libcamera/camera_sensor.cpp | 31 +++++++++++++++++++++++++++++++
 1 file changed, 31 insertions(+)

(limited to 'src/libcamera/camera_sensor.cpp')

diff --git a/src/libcamera/camera_sensor.cpp b/src/libcamera/camera_sensor.cpp
index 350f49ac..79b2bc40 100644
--- a/src/libcamera/camera_sensor.cpp
+++ b/src/libcamera/camera_sensor.cpp
@@ -13,10 +13,12 @@
 #include <limits.h>
 #include <math.h>
 #include <regex>
+#include <string.h>
 
 #include <libcamera/property_ids.h>
 
 #include "libcamera/internal/formats.h"
+#include "libcamera/internal/sysfs.h"
 #include "libcamera/internal/utils.h"
 
 /**
@@ -204,6 +206,11 @@ int CameraSensor::init()
 	if (ret < 0)
 		return ret;
 
+	/* Generate a unique ID for the sensor. */
+	ret = generateId();
+	if (ret)
+		return ret;
+
 	/* Retrieve and store the camera sensor properties. */
 	const ControlInfoMap &controls = subdev_->controls();
 	int32_t propertyValue;
@@ -541,4 +548,28 @@ std::string CameraSensor::logPrefix() const
 	return "'" + entity_->name() + "'";
 }
 
+int CameraSensor::generateId()
+{
+	const std::string devPath = subdev_->devicePath();
+
+	/* Try to get ID from firmware description. */
+	id_ = sysfs::firmwareNodePath(devPath);
+	if (!id_.empty())
+		return 0;
+
+	/*
+	 * Virtual sensors not described in firmware
+	 *
+	 * Verify it's a platform device and construct ID from the deive path
+	 * and model of sensor.
+	 */
+	if (devPath.find("/sys/devices/platform/", 0) == 0) {
+		id_ = devPath.substr(strlen("/sys/devices/")) + " " + model();
+		return 0;
+	}
+
+	LOG(CameraSensor, Error) << "Can't generate sensor ID";
+	return -EINVAL;
+}
+
 } /* namespace libcamera */
-- 
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