ALSA: pcm: Convert params_*() with static inline functions

... and add proper kerneldoc comments.
There is no big reason to keep them as macros.  Static inline
functions are safer in general, and suitable for kerneldoc, too.

Signed-off-by: Takashi Iwai <tiwai@suse.de>

include/sound/pcm.h

@@ -841,18 +841,59 @@ static inline const struct snd_interval *hw_param_interval_c(const struct snd_pc
 	return &params->intervals[var - SNDRV_PCM_HW_PARAM_FIRST_INTERVAL];
 }
 
-#define params_channels(p) \
-	(hw_param_interval_c((p), SNDRV_PCM_HW_PARAM_CHANNELS)->min)
-#define params_rate(p) \
-	(hw_param_interval_c((p), SNDRV_PCM_HW_PARAM_RATE)->min)
-#define params_period_size(p) \
-	(hw_param_interval_c((p), SNDRV_PCM_HW_PARAM_PERIOD_SIZE)->min)
-#define params_periods(p) \
-	(hw_param_interval_c((p), SNDRV_PCM_HW_PARAM_PERIODS)->min)
-#define params_buffer_size(p) \
-	(hw_param_interval_c((p), SNDRV_PCM_HW_PARAM_BUFFER_SIZE)->min)
-#define params_buffer_bytes(p) \
-	(hw_param_interval_c((p), SNDRV_PCM_HW_PARAM_BUFFER_BYTES)->min)
+/**
+ * params_channels - Get the number of channels from the hw params
+ * @p: hw params
+ */
+static inline unsigned int params_channels(const struct snd_pcm_hw_params *p)
+{
+	return hw_param_interval_c(p, SNDRV_PCM_HW_PARAM_CHANNELS)->min;
+}
+
+/**
+ * params_channels - Get the sample rate from the hw params
+ * @p: hw params
+ */
+static inline unsigned int params_rate(const struct snd_pcm_hw_params *p)
+{
+	return hw_param_interval_c(p, SNDRV_PCM_HW_PARAM_RATE)->min;
+}
+
+/**
+ * params_channels - Get the period size (in frames) from the hw params
+ * @p: hw params
+ */
+static inline unsigned int params_period_size(const struct snd_pcm_hw_params *p)
+{
+	return hw_param_interval_c(p, SNDRV_PCM_HW_PARAM_PERIOD_SIZE)->min;
+}
+
+/**
+ * params_channels - Get the number of periods from the hw params
+ * @p: hw params
+ */
+static inline unsigned int params_periods(const struct snd_pcm_hw_params *p)
+{
+	return hw_param_interval_c(p, SNDRV_PCM_HW_PARAM_PERIODS)->min;
+}
+
+/**
+ * params_channels - Get the buffer size (in frames) from the hw params
+ * @p: hw params
+ */
+static inline unsigned int params_buffer_size(const struct snd_pcm_hw_params *p)
+{
+	return hw_param_interval_c(p, SNDRV_PCM_HW_PARAM_BUFFER_SIZE)->min;
+}
+
+/**
+ * params_channels - Get the buffer size (in bytes) from the hw params
+ * @p: hw params
+ */
+static inline unsigned int params_buffer_bytes(const struct snd_pcm_hw_params *p)
+{
+	return hw_param_interval_c(p, SNDRV_PCM_HW_PARAM_BUFFER_BYTES)->min;
+}
 
 int snd_interval_refine(struct snd_interval *i, const struct snd_interval *v);
 void snd_interval_mul(const struct snd_interval *a, const struct snd_interval *b, struct snd_interval *c);