ASoC: Add bit clock rate calculator utility functions

Many devices need to calculate the bit clock rate desired to
work out the clock configuration required for the device.
Provide utility functions to do this using both hw_params
structures and raw numbers.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Liam Girdwood <lrg@slimlogic.co.uk>

include/sound/soc.h

@@ -227,6 +227,11 @@ int snd_soc_codec_set_cache_io(struct snd_soc_codec *codec,
 void snd_soc_free_pcms(struct snd_soc_device *socdev);
 int snd_soc_new_pcms(struct snd_soc_device *socdev, int idx, const char *xid);
 
+/* Utility functions to get clock rates from various things */
+int snd_soc_calc_frame_size(int sample_size, int channels, int tdm_slots);
+int snd_soc_params_to_frame_size(struct snd_pcm_hw_params *params);
+int snd_soc_params_to_bclk(struct snd_pcm_hw_params *parms);
+
 /* set runtime hw params */
 int snd_soc_set_runtime_hwparams(struct snd_pcm_substream *substream,
 	const struct snd_pcm_hardware *hw);

sound/soc/Makefile

-snd-soc-core-objs := soc-core.o soc-dapm.o soc-jack.o soc-cache.o
+snd-soc-core-objs := soc-core.o soc-dapm.o soc-jack.o soc-cache.o soc-utils.o
 
 obj-$(CONFIG_SND_SOC)	+= snd-soc-core.o
 obj-$(CONFIG_SND_SOC)	+= codecs/

sound/soc/soc-utils.c

+/*
+ * soc-util.c  --  ALSA SoC Audio Layer utility functions
+ *
+ * Copyright 2009 Wolfson Microelectronics PLC.
+ *
+ * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
+ *         Liam Girdwood <lrg@slimlogic.co.uk>
+ *         
+ *
+ *  This program is free software; you can redistribute  it and/or modify it
+ *  under  the terms of  the GNU General  Public License as published by the
+ *  Free Software Foundation;  either version 2 of the  License, or (at your
+ *  option) any later version.
+ */
+
+#include <sound/core.h>
+#include <sound/pcm.h>
+#include <sound/pcm_params.h>
+#include <sound/soc.h>
+
+int snd_soc_calc_frame_size(int sample_size, int channels, int tdm_slots)
+{
+	return sample_size * channels * tdm_slots;
+}
+EXPORT_SYMBOL_GPL(snd_soc_calc_frame_size);
+
+int snd_soc_params_to_frame_size(struct snd_pcm_hw_params *params)
+{
+	int sample_size;
+
+	switch (params_format(params)) {
+	case SNDRV_PCM_FORMAT_S16_LE:
+	case SNDRV_PCM_FORMAT_S16_BE:
+		sample_size = 16;
+		break;
+	case SNDRV_PCM_FORMAT_S20_3LE:
+	case SNDRV_PCM_FORMAT_S20_3BE:
+		sample_size = 20;
+		break;
+	case SNDRV_PCM_FORMAT_S24_LE:
+	case SNDRV_PCM_FORMAT_S24_BE:
+		sample_size = 24;
+		break;
+	case SNDRV_PCM_FORMAT_S32_LE:
+	case SNDRV_PCM_FORMAT_S32_BE:
+		sample_size = 32;
+		break;
+	default:
+		return -ENOTSUPP;
+	}
+
+	return snd_soc_calc_frame_size(sample_size, params_channels(params),
+				       1);
+}
+EXPORT_SYMBOL_GPL(snd_soc_params_to_frame_size);
+
+int snd_soc_params_to_bclk(struct snd_pcm_hw_params *params)
+{
+	int ret;
+
+	ret = snd_soc_params_to_frame_size(params);
+
+	if (ret > 0)
+		return ret * params_rate(params);
+	else
+		return ret;
+}
+EXPORT_SYMBOL_GPL(snd_soc_params_to_bclk);