diff --git a/include/sound/pcm_params.h b/include/sound/pcm_params.h
index 85cf1cf..f494f1e 100644
--- a/include/sound/pcm_params.h
+++ b/include/sound/pcm_params.h
@@ -337,5 +337,19 @@
 	return 0;
 }
 
-#endif /* __SOUND_PCM_PARAMS_H */
+#define params_access(p) ((__force snd_pcm_access_t)\
+		snd_mask_min(hw_param_mask_c((p), SNDRV_PCM_HW_PARAM_ACCESS)))
+#define params_format(p) ((__force snd_pcm_format_t)\
+		snd_mask_min(hw_param_mask_c((p), SNDRV_PCM_HW_PARAM_FORMAT)))
+#define params_subformat(p) \
+	snd_mask_min(hw_param_mask_c((p), SNDRV_PCM_HW_PARAM_SUBFORMAT))
 
+static inline unsigned int
+params_period_bytes(const struct snd_pcm_hw_params *p)
+{
+	return (params_period_size(p) *
+		snd_pcm_format_physical_width(params_format(p)) *
+		params_channels(p)) / 8;
+}
+
+#endif /* __SOUND_PCM_PARAMS_H */