isp: Add histogram supporthistogram

Support enabling the histogram statistics engine and retrieving
histogram data. Histogram data is currently ignored in the image quality
tuning implementation.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

1 files changed, 32 insertions, 5 deletions

diff --git a/isp/stats.h b/isp/stats.h
index fb6c26a..f68d4fa 100644
--- a/isp/stats.h
+++ b/isp/stats.h
@@ -27,6 +27,11 @@
 
 struct omap3_isp_device;
 
+enum omap3_isp_stat_engine {
+	OMAP3_ISP_STAT_AEWB = 1 << 0,
+	OMAP3_ISP_STAT_HIST = 1 << 1,
+};
+
 /*
  * struct omap3_isp_aewb_stats - OMAP3 ISP AEWB statistics
  * @npix: Total number of accumulated pixels
@@ -52,15 +57,28 @@ struct omap3_isp_aewb_stats {
 };
 
 /*
+ * struct omap3_isp_histogram_stats - OMAP3 ISP histogram statistics
+ * @nbins: Number of bins in the histogram
+ * @bins: Array of histogram frequency data
+ *
+ * Each bin entry is stored on 32 bits but limited to 20 bits.
+ */
+struct omap3_isp_histogram_stats {
+	unsigned int nbins;
+	uint32_t *bins;
+};
+
+/*
  * omap3_isp_stats_enable - Enable or disable the statistics engine
  * @isp: The ISP device
- * @enable: Whether to enable to disable the statistics engine
+ * @which: The statistics engine(s) to enable
  *
- * The statistics engine must be enabled prior to starting the video stream.
- * When enabled, it statistics will be computed for every frame and delivered
- * through the ISP aewb_ready() callback.
+ * The statistics engines must be enabled prior to starting the video stream.
+ * When enabled, statistics will be computed for every frame and delivered
+ * through the ISP aewb_ready() and histogram_ready() callbacks.
  */
-void omap3_isp_stats_enable(struct omap3_isp_device *isp, bool enable);
+void omap3_isp_stats_enable(struct omap3_isp_device *isp,
+			    enum omap3_isp_stat_engine which);
 
 /*
  * omap3_isp_stats_get_format - Get frame format at the statistics engine input
@@ -72,6 +90,7 @@ void omap3_isp_stats_enable(struct omap3_isp_device *isp, bool enable);
  */
 int omap3_isp_stats_get_format(struct omap3_isp_device *isp,
 			       struct v4l2_mbus_framefmt *format);
+
 /*
  * omap3_isp_aewb_configure - Configure the AEWB statistics engine
  * @isp: The ISP device
@@ -81,4 +100,12 @@ int omap3_isp_stats_get_format(struct omap3_isp_device *isp,
 int omap3_isp_aewb_configure(struct omap3_isp_device *isp, struct v4l2_rect *rect,
 			     unsigned int saturation);
 
+/*
+ * omap3_isp_histogram_configure - Configure the histogram statistics engine
+ * @isp: The ISP device
+ * @rect: The region of interest, relative to the sensor output frame size
+ */
+int omap3_isp_histogram_configure(struct omap3_isp_device *isp,
+				  struct v4l2_rect *rect);
+
 #endif