ALSA: hda: Upgrade stream-format infrastructure

Introduce a set of functions that ultimately facilite SDxFMT-related
calculations in atomic manner:

First, introduce snd_pcm_subformat_width() and snd_pcm_hw_params_bits()
helpers that separate the base functionality from the HDAudio-specific
one.

snd_hdac_format_normalize() - format converter. S20_LE, S24_LE and their
unsigned and BE friends are invalid from HDAudio perspective but still
can be specified as function argument due to compatibility reasons.

snd_hdac_stream_format_bits() - obtain just the bits-per-sample value.
Does not ignore subformat and msbits parameters.

snd_hdac_stream_format() and snd_hdac_spdif_stream_format() - obtain the
SDxFMT value given the audio format parameters. The former is stripped
away of spdif-related information. Useful for users that do not care
about them.

Acked-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Cezary Rojewski <cezary.rojewski@intel.com>
Acked-by: Jaroslav Kysela <perex@perex.cz>
Link: https://lore.kernel.org/r/20231117120610.1755254-5-cezary.rojewski@intel.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>

include/sound/hdaudio.h

@@ -140,6 +140,11 @@ int snd_hdac_get_connections(struct hdac_device *codec, hda_nid_t nid,
 			     hda_nid_t *conn_list, int max_conns);
 int snd_hdac_get_sub_nodes(struct hdac_device *codec, hda_nid_t nid,
 			   hda_nid_t *start_id);
+unsigned int snd_hdac_stream_format_bits(snd_pcm_format_t format, snd_pcm_subformat_t subformat,
+					 unsigned int maxbits);
+unsigned int snd_hdac_stream_format(unsigned int channels, unsigned int bits, unsigned int rate);
+unsigned int snd_hdac_spdif_stream_format(unsigned int channels, unsigned int bits,
+					  unsigned int rate, unsigned short spdif_ctls);
 unsigned int snd_hdac_calc_stream_format(unsigned int rate,
 					 unsigned int channels,
 					 snd_pcm_format_t format,

include/sound/pcm_params.h

@@ -362,6 +362,8 @@ static inline int params_physical_width(const struct snd_pcm_hw_params *p)
 	return snd_pcm_format_physical_width(params_format(p));
 }
 
+int snd_pcm_hw_params_bits(const struct snd_pcm_hw_params *p);
+
 static inline void
 params_set_format(struct snd_pcm_hw_params *p, snd_pcm_format_t fmt)
 {

sound/core/pcm_lib.c

@@ -1706,6 +1706,40 @@ int snd_pcm_hw_param_last(struct snd_pcm_substream *pcm,
 }
 EXPORT_SYMBOL(snd_pcm_hw_param_last);
 
+/**
+ * snd_pcm_hw_params_bits - Get the number of bits per the sample.
+ * @p: hardware parameters
+ *
+ * Return: The number of bits per sample based on the format,
+ * subformat and msbits the specified hw params has.
+ */
+int snd_pcm_hw_params_bits(const struct snd_pcm_hw_params *p)
+{
+	snd_pcm_subformat_t subformat = params_subformat(p);
+	snd_pcm_format_t format = params_format(p);
+
+	switch (format) {
+	case SNDRV_PCM_FORMAT_S32_LE:
+	case SNDRV_PCM_FORMAT_U32_LE:
+	case SNDRV_PCM_FORMAT_S32_BE:
+	case SNDRV_PCM_FORMAT_U32_BE:
+		switch (subformat) {
+		case SNDRV_PCM_SUBFORMAT_MSBITS_20:
+			return 20;
+		case SNDRV_PCM_SUBFORMAT_MSBITS_24:
+			return 24;
+		case SNDRV_PCM_SUBFORMAT_MSBITS_MAX:
+		case SNDRV_PCM_SUBFORMAT_STD:
+		default:
+			break;
+		}
+		fallthrough;
+	default:
+		return snd_pcm_format_width(format);
+	}
+}
+EXPORT_SYMBOL(snd_pcm_hw_params_bits);
+
 static int snd_pcm_lib_ioctl_reset(struct snd_pcm_substream *substream,
 				   void *arg)
 {

sound/hda/hdac_device.c

@@ -13,6 +13,7 @@
 #include <sound/hdaudio.h>
 #include <sound/hda_regmap.h>
 #include <sound/pcm.h>
+#include <sound/pcm_params.h>
 #include "local.h"
 
 static void setup_fg_nodes(struct hdac_device *codec);
@@ -725,6 +726,129 @@ static const struct hda_rate_tbl rate_bits[] = {
 	{ 0 } /* terminator */
 };
 
+static snd_pcm_format_t snd_hdac_format_normalize(snd_pcm_format_t format)
+{
+	switch (format) {
+	case SNDRV_PCM_FORMAT_S20_LE:
+	case SNDRV_PCM_FORMAT_S24_LE:
+		return SNDRV_PCM_FORMAT_S32_LE;
+
+	case SNDRV_PCM_FORMAT_U20_LE:
+	case SNDRV_PCM_FORMAT_U24_LE:
+		return SNDRV_PCM_FORMAT_U32_LE;
+
+	case SNDRV_PCM_FORMAT_S20_BE:
+	case SNDRV_PCM_FORMAT_S24_BE:
+		return SNDRV_PCM_FORMAT_S32_BE;
+
+	case SNDRV_PCM_FORMAT_U20_BE:
+	case SNDRV_PCM_FORMAT_U24_BE:
+		return SNDRV_PCM_FORMAT_U32_BE;
+
+	default:
+		return format;
+	}
+}
+
+/**
+ * snd_hdac_stream_format_bits - obtain bits per sample value.
+ * @format:	the PCM format.
+ * @subformat:	the PCM subformat.
+ * @maxbits:	the maximum bits per sample.
+ *
+ * Return: The number of bits per sample.
+ */
+unsigned int snd_hdac_stream_format_bits(snd_pcm_format_t format, snd_pcm_subformat_t subformat,
+					 unsigned int maxbits)
+{
+	struct snd_pcm_hw_params params;
+	unsigned int bits;
+
+	memset(&params, 0, sizeof(params));
+
+	params_set_format(&params, snd_hdac_format_normalize(format));
+	snd_mask_set(hw_param_mask(&params, SNDRV_PCM_HW_PARAM_SUBFORMAT),
+		     (__force unsigned int)subformat);
+
+	bits = snd_pcm_hw_params_bits(&params);
+	if (maxbits)
+		return min(bits, maxbits);
+	return bits;
+}
+EXPORT_SYMBOL_GPL(snd_hdac_stream_format_bits);
+
+/**
+ * snd_hdac_stream_format - convert format parameters to SDxFMT value.
+ * @channels:	the number of channels.
+ * @bits:	bits per sample.
+ * @rate:	the sample rate.
+ *
+ * Return: The format bitset or zero if invalid.
+ */
+unsigned int snd_hdac_stream_format(unsigned int channels, unsigned int bits, unsigned int rate)
+{
+	unsigned int val = 0;
+	int i;
+
+	for (i = 0; rate_bits[i].hz; i++) {
+		if (rate_bits[i].hz == rate) {
+			val = rate_bits[i].hda_fmt;
+			break;
+		}
+	}
+
+	if (!rate_bits[i].hz)
+		return 0;
+
+	if (channels == 0 || channels > 8)
+		return 0;
+	val |= channels - 1;
+
+	switch (bits) {
+	case 8:
+		val |= AC_FMT_BITS_8;
+		break;
+	case 16:
+		val |= AC_FMT_BITS_16;
+		break;
+	case 20:
+		val |= AC_FMT_BITS_20;
+		break;
+	case 24:
+		val |= AC_FMT_BITS_24;
+		break;
+	case 32:
+		val |= AC_FMT_BITS_32;
+		break;
+	default:
+		return 0;
+	}
+
+	return val;
+}
+EXPORT_SYMBOL_GPL(snd_hdac_stream_format);
+
+/**
+ * snd_hdac_spdif_stream_format - convert format parameters to SDxFMT value.
+ * @channels:	the number of channels.
+ * @bits:	bits per sample.
+ * @rate:	the sample rate.
+ * @spdif_ctls:	HD-audio SPDIF status bits (0 if irrelevant).
+ *
+ * Return: The format bitset or zero if invalid.
+ */
+unsigned int snd_hdac_spdif_stream_format(unsigned int channels, unsigned int bits,
+					  unsigned int rate, unsigned short spdif_ctls)
+{
+	unsigned int val = snd_hdac_stream_format(channels, bits, rate);
+
+	if (val && spdif_ctls & AC_DIG1_NONAUDIO)
+		val |= AC_FMT_TYPE_NON_PCM;
+
+	return val;
+}
+EXPORT_SYMBOL_GPL(snd_hdac_spdif_stream_format);
+
 /**
  * snd_hdac_calc_stream_format - calculate the format bitset
  * @rate: the sample rate