From 68863657530812a21073fa463987fd414e1236bb Mon Sep 17 00:00:00 2001
From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Date: Tue, 28 Apr 2020 00:53:01 +0300
Subject: libcamera: camera_sensor: Add model() function

Add a new model() function to the CameraSensor class to report the
camera sensor model.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
---
 src/libcamera/camera_sensor.cpp | 40 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 40 insertions(+)

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

diff --git a/src/libcamera/camera_sensor.cpp b/src/libcamera/camera_sensor.cpp
index 7c1d9b9e..3d7cedca 100644
--- a/src/libcamera/camera_sensor.cpp
+++ b/src/libcamera/camera_sensor.cpp
@@ -12,6 +12,7 @@
 #include <iomanip>
 #include <limits.h>
 #include <math.h>
+#include <regex>
 
 #include <libcamera/property_ids.h>
 
@@ -87,6 +88,35 @@ int CameraSensor::init()
 		return -EINVAL;
 	}
 
+	/*
+	 * Extract the camera sensor model name from the media entity name.
+	 *
+	 * There is no standardized naming scheme for sensor entities in the
+	 * Linux kernel at the moment.
+	 *
+	 * - The most common rule, used by I2C sensors, associates the model
+	 *   name with the I2C bus number and address (e.g. 'imx219 0-0010').
+	 *
+	 * - When the sensor exposes multiple subdevs, the model name is
+	 *   usually followed by a function name, as in the smiapp driver (e.g.
+	 *   'jt8ew9 pixel_array 0-0010').
+	 *
+	 * - The vimc driver names its sensors 'Sensor A' and 'Sensor B'.
+	 *
+	 * Other schemes probably exist. As a best effort heuristic, use the
+	 * part of the entity name before the first space if the name contains
+	 * an I2C address, and use the full entity name otherwise.
+	 */
+	std::string entityName = entity_->name();
+	std::regex i2cRegex{ " [0-9]+-[0-9a-f]{4}" };
+	std::smatch match;
+
+	if (std::regex_search(entityName, match, i2cRegex))
+		model_ = entityName.substr(0, entityName.find(' '));
+	else
+		model_ = entityName;
+
+	/* Open the subdev. */
 	ret = subdev_->open();
 	if (ret < 0)
 		return ret;
@@ -163,6 +193,16 @@ int CameraSensor::init()
 	return 0;
 }
 
+/**
+ * \fn CameraSensor::model()
+ * \brief Retrieve the sensor model name
+ *
+ * The sensor model name is a free-formed string that uniquely identifies the
+ * sensor model.
+ *
+ * \return The sensor model name
+ */
+
 /**
  * \fn CameraSensor::entity()
  * \brief Retrieve the sensor media entity
-- 
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