Each entry in the array is a 20 bits value composed of 16 bits unsigned integer and 4 bits fractional part. So the type should change to __u32. In addition add a documentation of how the measurements are done. Signed-off-by: Dafna Hirschfeld <dafna.hirschfeld@xxxxxxxxxxxxx> --- include/uapi/linux/rkisp1-config.h | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/include/uapi/linux/rkisp1-config.h b/include/uapi/linux/rkisp1-config.h index 6e449e784260..24f05d6d258f 100644 --- a/include/uapi/linux/rkisp1-config.h +++ b/include/uapi/linux/rkisp1-config.h @@ -844,13 +844,18 @@ struct rkisp1_cif_isp_af_stat { /** * struct rkisp1_cif_isp_hist_stat - statistics histogram data * - * @hist_bins: measured bin counters + * @hist_bins: measured bin counters. Each bin is a 20 bits unsigned fixed point + * type. Bits 0-4 are the fractional part and bits 5-19 are the + * integer part. * - * Measurement window divided into 25 sub-windows, set - * with ISP_HIST_XXX + * The window of the measurements area is divided to 5x5 sub-windows. The + * histogram is then computed for each sub-window independently and the final + * result is a weighted average of the histogram measurements on all + * sub-windows. The window of the measurements area and the weight of each + * sub-window are configurable using struct @rkisp1_cif_isp_hst_config. */ struct rkisp1_cif_isp_hist_stat { - __u16 hist_bins[RKISP1_CIF_ISP_HIST_BIN_N_MAX]; + __u32 hist_bins[RKISP1_CIF_ISP_HIST_BIN_N_MAX]; }; /** -- 2.17.1