CAL_PIX_PROC
val = cal_read(ctx->cal, CAL_PIX_PROC(ctx->pix_proc));
cal_write(ctx->cal, CAL_PIX_PROC(ctx->pix_proc), val);
cal_read(ctx->cal, CAL_PIX_PROC(ctx->pix_proc)));
cal_write(ctx->cal, CAL_PIX_PROC(ctx->pix_proc), 0);