media: rppx1: hist: Add support histogram measurement

Extend the RPPX1 driver to allow setting the histogram measurement
configuration and consuming the resulting statistics. It uses the RPPX1
framework for parameters and its writer abstraction to allow the user to
control how, and when, configuration is applied to the RPPX1.

Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Co-developed-by: Jai Luthra <jai.luthra+renesas@ideasonboard.com>
Signed-off-by: Jai Luthra <jai.luthra+renesas@ideasonboard.com>
Co-developed-by: Jacopo Mondi <jacopo.mondi+renesas@ideasonboard.com>
Signed-off-by: Jacopo Mondi <jacopo.mondi+renesas@ideasonboard.com>
Reviewed-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>

1 files changed, 115 insertions, 2 deletions

diff --git a/include/uapi/linux/media/dreamchip/rppx1-config.h b/include/uapi/linux/media/dreamchip/rppx1-config.h
index 6864df2d4436..934e18731b08 100644
--- a/include/uapi/linux/media/dreamchip/rppx1-config.h
+++ b/include/uapi/linux/media/dreamchip/rppx1-config.h
@@ -82,6 +82,9 @@ enum rppx1_meas_chan {
  * @RPPX1_PARAMS_BLOCK_TYPE_AWBG_POST: MAIN_POST White Balance Gains
  * @RPPX1_PARAMS_BLOCK_TYPE_EXM_PRE1: PRE1 pipe Exposure Measurement
  * @RPPX1_PARAMS_BLOCK_TYPE_EXM_PRE2: PRE2 pipe Exposure Measurement
+ * @RPPX1_PARAMS_BLOCK_TYPE_HIST_PRE1: PRE1 pipe Histogram Measurement
+ * @RPPX1_PARAMS_BLOCK_TYPE_HIST_PRE2: PRE2 pipe Histogram Measurement
+ * @RPPX1_PARAMS_BLOCK_TYPE_HIST_POST: POST pipe Histogram Measurement
  */
 enum rppx1_params_block_type {
 	RPPX1_PARAMS_BLOCK_TYPE_WBMEAS_POST,
@@ -90,6 +93,9 @@ enum rppx1_params_block_type {
 	RPPX1_PARAMS_BLOCK_TYPE_AWBG_POST,
 	RPPX1_PARAMS_BLOCK_TYPE_EXM_PRE1,
 	RPPX1_PARAMS_BLOCK_TYPE_EXM_PRE2,
+	RPPX1_PARAMS_BLOCK_TYPE_HIST_PRE1,
+	RPPX1_PARAMS_BLOCK_TYPE_HIST_PRE2,
+	RPPX1_PARAMS_BLOCK_TYPE_HIST_POST,
 };
 
 /**
@@ -243,6 +249,87 @@ struct rppx1_exm_params {
 	__u8 reserved[3];
 };
 
+/* Histogram */
+#define RPPX1_HIST_WEIGHT_GRIDS_SIZE 25
+
+/**
+ * enum rppx1_hist_mode - Histogram measurement mode
+ *
+ * Histogram measurement mode. Select which channel or combination of channels
+ * the histogram measurement is performed on.
+ *
+ * @RPPX1_HIST_MODE_DISABLE: histogram disabled
+ * @RPPX1_HIST_MODE_RGB_COMBINED: combined RGB histogram
+ * @RPPX1_HIST_MODE_R_HISTOGRAM: red channel histogram
+ * @RPPX1_HIST_MODE_GR_HISTOGRAM: green/red channel histogram
+ * @RPPX1_HIST_MODE_B_HISTOGRAM: blue channel histogram
+ * @RPPX1_HIST_MODE_GB_HISTOGRAM: green/blue histogram
+ */
+enum rppx1_hist_mode {
+	RPPX1_HIST_MODE_DISABLE,
+	RPPX1_HIST_MODE_RGB_COMBINED,
+	RPPX1_HIST_MODE_R_HISTOGRAM,
+	RPPX1_HIST_MODE_GR_HISTOGRAM,
+	RPPX1_HIST_MODE_B_HISTOGRAM,
+	RPPX1_HIST_MODE_GB_HISTOGRAM,
+};
+
+/**
+ * struct rppx1_hist_params - Histogram measurement configuration
+ *
+ * The RPP-X1 Histogram measurement unit is available on the PRE1, PRE2 and
+ * MAIN_POST pipes. Userspace selects which pipe to operate by setting the
+ * @header.type field to RPPX1_PARAMS_BLOCK_TYPE_HIST_PRE1,
+ * RPPX1_PARAMS_BLOCK_TYPE_HIST_PRE2 or
+ * RPPX1_PARAMS_BLOCK_TYPE_HIST_POST.
+ *
+ * The histogram measurement point is selected using the @channel field while
+ * histogram measurement mode is selected using the @mode field.
+ *
+ * Histogram measurement is performed by programming subsampling factors using
+ * the @v_stepsize and @h_step_inc fields and by weighted windowing, by
+ * programming the size of the measurement window @wnd with @weights associated
+ * to each cell of the 5x5 measurement grid. Weights are represented as 5 bits
+ * integer values ranging from 0 to 16.
+ *
+ * The @last_line fields controls when the histogram measurement completes. It
+ * is usually programmed to the value of (@wnd.v_offs + @wnd.v_size - 1).
+ *
+ * Histogram values are calculated by applying a per-color channel coefficient
+ * represented as an 8 bits unsigned Q1.7 integer value. The @sample_offs and
+ * @sample_shift fields allow to reduce the color dynamic range on which
+ * histogram data are produced.
+ *
+ * @header: block header (type = RPPX1_PARAMS_BLOCK_TYPE_HIST_PRE1,
+ *	    type = RPPX1_PARAMS_BLOCK_TYPE_HIST_PRE2 or
+ *	    type = RPPX1_PARAMS_BLOCK_TYPE_HIST_POST)
+ * @wnd: measurement window coordinates
+ * @last_line: line number for which the histogram measurement completes
+ * @v_stepsize: vertical subsampling divider, 7 bits
+ * @h_step_inc: horizontal subsampling step counter, 17 bits
+ * @sample_offs: sample offset, 24 bits
+ * @mode: histogram measurement mode (from enum rppx1_hist_mode)
+ * @channel_sel: histogram measurement point (see enum rppx1_meas_chan)
+ * @weights: weighting factors for each sub-window (5x5 grid)
+ * @coeff: R-G-B coefficients, 8 bits unsigned Q1.7
+ * @sample_shift: sample shift, 4 bits
+ * @reserved: padding
+ */
+struct rppx1_hist_params {
+	struct v4l2_isp_params_block_header header;
+	struct rppx1_window wnd;
+	__u32 last_line;
+	__u32 v_stepsize;
+	__u32 h_step_inc;
+	__u32 sample_offs;
+	__u8 mode;
+	__u8 channel_sel;
+	__u8 weights[RPPX1_HIST_WEIGHT_GRIDS_SIZE];
+	__u8 coeff[3];
+	__u8 sample_shift;
+	__u8 reserved;
+};
+
 /**
  * RPPX1_PARAMS_MAX_SIZE - Maximum size of all RPP-X1 parameter blocks
  *
@@ -255,7 +342,10 @@ struct rppx1_exm_params {
 	sizeof(struct rppx1_awbg_params)			+	\
 	sizeof(struct rppx1_awbg_params)			+	\
 	sizeof(struct rppx1_exm_params)				+	\
-	sizeof(struct rppx1_exm_params))
+	sizeof(struct rppx1_exm_params)				+	\
+	sizeof(struct rppx1_hist_params)			+	\
+	sizeof(struct rppx1_hist_params)			+	\
+	sizeof(struct rppx1_hist_params))
 
 /* ---------------------------------------------------------------------------
  * Statistics Structures
@@ -274,11 +364,17 @@ struct rppx1_exm_params {
  * @RPPX1_STATS_BLOCK_TYPE_WBMEAS_POST: post-fusion white-balance measurement
  * @RPPX1_STATS_BLOCK_TYPE_EXM_PRE1: pre-fusion pipe1 exposure measurement
  * @RPPX1_STATS_BLOCK_TYPE_EXM_PRE2: pre-fusion pipe2 exposure measurement
+ * @RPPX1_STATS_BLOCK_TYPE_HIST_PRE1: pre-fusion pipe1 histogram
+ * @RPPX1_STATS_BLOCK_TYPE_HIST_PRE2: pre-fusion pipe2 histogram
+ * @RPPX1_STATS_BLOCK_TYPE_HIST_POST: post-fusion histogram
  */
 enum rppx1_stats_block_type {
 	RPPX1_STATS_BLOCK_TYPE_WBMEAS_POST,
 	RPPX1_STATS_BLOCK_TYPE_EXM_PRE1,
 	RPPX1_STATS_BLOCK_TYPE_EXM_PRE2,
+	RPPX1_STATS_BLOCK_TYPE_HIST_PRE1,
+	RPPX1_STATS_BLOCK_TYPE_HIST_PRE2,
+	RPPX1_STATS_BLOCK_TYPE_HIST_POST,
 };
 
 /**
@@ -317,6 +413,20 @@ struct rppx1_exm_stats {
 	__u32 reserved;
 };
 
+/* Histogram */
+#define RPPX1_HIST_NUM_BINS 32
+
+/**
+ * struct rppx1_hist_stats - Histogram statistics
+ *
+ * @header: block header (type = RPPX1_STATS_BLOCK_TYPE_HIST_POST)
+ * @hist_bins: accumulation histogram results in unsigned 20-bit Q16.4 format
+ */
+struct rppx1_hist_stats {
+	struct v4l2_isp_block_header header;
+	__u32 hist_bins[RPPX1_HIST_NUM_BINS];
+};
+
 /**
  * RPPX1_STATS_MAX_SIZE - Maximum size of all RPP-X1 statistics
  *
@@ -326,6 +436,9 @@ struct rppx1_exm_stats {
 #define RPPX1_STATS_MAX_SIZE						\
 	(sizeof(struct rppx1_wbmeas_stats)			+	\
 	sizeof(struct rppx1_exm_stats)				+	\
-	sizeof(struct rppx1_exm_stats))
+	sizeof(struct rppx1_exm_stats)				+	\
+	sizeof(struct rppx1_hist_stats)				+	\
+	sizeof(struct rppx1_hist_stats)				+	\
+	sizeof(struct rppx1_hist_stats))
 
 #endif /* __UAPI_RPP_X1_CONFIG_H */