diff --git a/include/sound/soc-dai.h b/include/sound/soc-dai.h index 6a42812bba8cad..df010a91b35059 100644 --- a/include/sound/soc-dai.h +++ b/include/sound/soc-dai.h @@ -17,6 +17,7 @@ struct snd_pcm_substream; struct snd_soc_dapm_widget; struct snd_compr_stream; +struct clk; /* * DAI hardware audio formats. @@ -188,6 +189,8 @@ int snd_soc_dai_set_pll(struct snd_soc_dai *dai, int snd_soc_dai_set_bclk_ratio(struct snd_soc_dai *dai, unsigned int ratio); +void snd_soc_dai_set_bclk_clk(struct snd_soc_dai *dai, struct clk *bclk); + /* Digital Audio interface formatting */ int snd_soc_dai_get_fmt_max_priority(const struct snd_soc_pcm_runtime *rtd); u64 snd_soc_dai_get_fmt(const struct snd_soc_dai *dai, int priority); @@ -473,6 +476,10 @@ struct snd_soc_dai { unsigned int symmetric_channels; unsigned int symmetric_sample_bits; + /* shared BCLK clock for cross-DAI rate constraints */ + struct clk *bclk; + unsigned int bclk_ratio; /* BCLK = rate * bclk_ratio (0 = use channels * sample_bits) */ + /* parent platform/codec */ struct snd_soc_component *component; diff --git a/sound/soc/soc-dai.c b/sound/soc/soc-dai.c index 2f370fda12665d..1719ddcefa4b03 100644 --- a/sound/soc/soc-dai.c +++ b/sound/soc/soc-dai.c @@ -116,10 +116,28 @@ int snd_soc_dai_set_bclk_ratio(struct snd_soc_dai *dai, unsigned int ratio) dai->driver->ops->set_bclk_ratio) ret = dai->driver->ops->set_bclk_ratio(dai, ratio); + if (!ret) + dai->bclk_ratio = ratio; + return soc_dai_ret(dai, ret); } EXPORT_SYMBOL_GPL(snd_soc_dai_set_bclk_ratio); +/** + * snd_soc_dai_set_bclk_clk - set the BCLK clock for shared clock detection + * @dai: DAI + * @bclk: BCLK clock pointer (or NULL to clear) + * + * When multiple DAIs share the same physical BCLK (detected via + * clk_is_match()), the ASoC core will automatically constrain their + * hw_params so that the resulting BCLK rates are compatible. + */ +void snd_soc_dai_set_bclk_clk(struct snd_soc_dai *dai, struct clk *bclk) +{ + dai->bclk = bclk; +} +EXPORT_SYMBOL_GPL(snd_soc_dai_set_bclk_clk); + int snd_soc_dai_get_fmt_max_priority(const struct snd_soc_pcm_runtime *rtd) { struct snd_soc_dai *dai; diff --git a/sound/soc/soc-pcm.c b/sound/soc/soc-pcm.c index 9b12eedb77c331..0e49290a8c903b 100644 --- a/sound/soc/soc-pcm.c +++ b/sound/soc/soc-pcm.c @@ -12,6 +12,7 @@ #include #include +#include #include #include #include @@ -26,6 +27,9 @@ #include #include + +DEFINE_GUARD(snd_soc_card_mutex, struct snd_soc_card *, + snd_soc_card_mutex_lock(_T), snd_soc_card_mutex_unlock(_T)) #define soc_pcm_ret(rtd, ret) _soc_pcm_ret(rtd, __func__, ret) static inline int _soc_pcm_ret(struct snd_soc_pcm_runtime *rtd, const char *func, int ret) @@ -467,6 +471,114 @@ static int soc_pcm_apply_symmetry(struct snd_pcm_substream *substream, return 0; } +/* + * Shared BCLK constraint: when multiple DAIs share the same physical BCLK, + * constrain hw_params so that the BCLK rate (rate * channels * sample_bits, + * or rate * slots * slot_width for TDM) remains consistent. + */ + +static int soc_pcm_shared_bclk_rule_rate(struct snd_pcm_hw_params *params, + struct snd_pcm_hw_rule *rule) +{ + struct snd_soc_dai *dai = rule->private; + struct snd_soc_card *card = dai->component->card; + struct snd_soc_pcm_runtime *rtd; + struct snd_soc_dai *other_dai; + unsigned long active_bclk_rate = 0; + struct snd_interval *rate = hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE); + struct snd_interval constraint = { .empty = 1 }; + unsigned int target_rate; + int i; + + /* Protect the rtd list traversal with the ASoC card mutex helper. */ + guard(snd_soc_card_mutex)(card); + + /* Scan all DAIs on the card for an active peer sharing the same BCLK */ + for_each_card_rtds(card, rtd) { + for_each_rtd_cpu_dais(rtd, i, other_dai) { + if (other_dai == dai) + continue; + if (!other_dai->bclk) + continue; + if (!snd_soc_dai_active(other_dai)) + continue; + /* + * Skip peers whose hw_params hasn't run yet. + * symmetric_rate is set by soc_pcm_set_dai_params() + * after snd_soc_dai_hw_params(), so non-zero means + * the DAI's clk_set_rate() has already executed. + */ + if (!other_dai->symmetric_rate) + continue; + if (!clk_is_match(dai->bclk, other_dai->bclk)) + continue; + + active_bclk_rate = clk_get_rate(other_dai->bclk); + if (active_bclk_rate) + goto found; + } + } + + return 0; + +found: + if (dai->bclk_ratio) { + /* + * Driver has set an explicit BCLK ratio (e.g. for TDM where + * BCLK = rate * slots * slot_width). The only valid rate is + * active_bclk_rate / bclk_ratio. + */ + target_rate = active_bclk_rate / dai->bclk_ratio; + + constraint.min = target_rate; + constraint.max = target_rate; + } else { + struct snd_interval *channels = hw_param_interval(params, + SNDRV_PCM_HW_PARAM_CHANNELS); + struct snd_interval *sample_bits = hw_param_interval(params, + SNDRV_PCM_HW_PARAM_SAMPLE_BITS); + + /* + * Default: BCLK = rate * channels * sample_bits. + * Calculate the range of valid rates given the current + * channel and sample_bits intervals. + */ + if (!channels->min || !sample_bits->min) + return 0; + + constraint.max = active_bclk_rate / + ((unsigned long)channels->min * sample_bits->min); + + if (channels->max && sample_bits->max) + constraint.min = active_bclk_rate / + ((unsigned long)channels->max * sample_bits->max); + else + constraint.min = constraint.max; + } + + constraint.integer = 1; + constraint.empty = 0; + + return snd_interval_refine(rate, &constraint); +} + +static int soc_pcm_apply_shared_bclk(struct snd_pcm_substream *substream, + struct snd_soc_dai *dai) +{ + if (!dai->bclk) + return 0; + + dev_dbg(dai->dev, + "ASoC: registering shared BCLK rate constraint\n"); + + return snd_pcm_hw_rule_add(substream->runtime, 0, + SNDRV_PCM_HW_PARAM_RATE, + soc_pcm_shared_bclk_rule_rate, dai, + SNDRV_PCM_HW_PARAM_CHANNELS, + SNDRV_PCM_HW_PARAM_SAMPLE_BITS, + -1); +} + static int soc_pcm_params_symmetry(struct snd_pcm_substream *substream, struct snd_pcm_hw_params *params) { @@ -903,6 +1015,13 @@ static int __soc_pcm_open(struct snd_soc_pcm_runtime *rtd, if (ret != 0) goto err; } + + /* Shared BCLK constraint across DAIs on the same card */ + for_each_rtd_cpu_dais(rtd, i, dai) { + ret = soc_pcm_apply_shared_bclk(substream, dai); + if (ret != 0) + goto err; + } dynamic: snd_soc_runtime_activate(rtd, substream->stream); ret = 0;