[PATCH v2] ASoC: qcom: sc8280xp: Derive TDM channels from DT mask

[PATCH v2] ASoC: qcom: sc8280xp: Derive TDM channels from DT mask

[Shawn Guo]

Derive the backend channel count of TDM DAIs from the cpu DAI TDM
slot mask in the DT, using the same DAI ID ranges and tx/rx mask
selection as q6tdm_set_tdm_slot(), so the channel count always matches
the number of slots programmed into the DSP. Each board then gets the
channel count its dai-link describes, e.g. 4/4 on Nord RRD, 6/4 on
RIDE. Keep the default of two when the link has no TDM slot
description.

Signed-off-by: Shawn Guo <shengchao.guo@oss.qualcomm.com>
---
Changes for v2:
- Cover all TDM DAIs (PRIMARY..QUINARY and AIF_TDM ranges), matching
  q6tdm_set_tdm_slot(), instead of only AIF_TDM_RX_8/TX_8 (Rafi)
- Link to v1: https://lore.kernel.org/all/20261021025310.2072026-1-shengchao.guo@oss.qualcomm.com/

 sound/soc/qcom/sc8280xp.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/sound/soc/qcom/sc8280xp.c b/sound/soc/qcom/sc8280xp.c
index 9aae6aadd43d..f5b147962afa 100644
--- a/sound/soc/qcom/sc8280xp.c
+++ b/sound/soc/qcom/sc8280xp.c
@@ -303,6 +303,22 @@ static int sc8280xp_be_hw_params_fixup(struct snd_soc_pcm_runtime *rtd,
 	channels->min = 2;
 	channels->max = 2;
 	switch (cpu_dai->id) {
+	case PRIMARY_TDM_RX_0 ... QUINARY_TDM_TX_7:
+	case AIF_TDM_RX_0 ... AIF_TDM_TX_12: {
+		struct qcom_snd_tdm_slot_cfg cpu_cfg, codec_cfg;
+		unsigned int mask;
+
+		if (qcom_snd_get_dai_tdm_slots(rtd, &cpu_cfg, &codec_cfg))
+			break;
+
+		/* Same slot mask selection as q6tdm_set_tdm_slot() */
+		mask = (cpu_dai->id & 0x1) ? cpu_cfg.tx_mask : cpu_cfg.rx_mask;
+		if (mask) {
+			channels->min = hweight32(mask);
+			channels->max = channels->min;
+		}
+		break;
+	}
 	case TX_CODEC_DMA_TX_0:
 	case TX_CODEC_DMA_TX_1:
 	case TX_CODEC_DMA_TX_2:
-- 
2.43.0

Re: [PATCH v2] ASoC: qcom: sc8280xp: Derive TDM channels from DT mask

[Prasad Kumpatla]

> diff --git a/sound/soc/qcom/sc8280xp.c b/sound/soc/qcom/sc8280xp.c
> index 9aae6aadd43d..f5b147962afa 100644
> --- a/sound/soc/qcom/sc8280xp.c
> +++ b/sound/soc/qcom/sc8280xp.c
> @@ -303,6 +303,22 @@ static int sc8280xp_be_hw_params_fixup(struct snd_soc_pcm_runtime *rtd,
>   	channels->min = 2;
>   	channels->max = 2;
>   	switch (cpu_dai->id) {
> +	case PRIMARY_TDM_RX_0 ... QUINARY_TDM_TX_7:
> +	case AIF_TDM_RX_0 ... AIF_TDM_TX_12: {
> +		struct qcom_snd_tdm_slot_cfg cpu_cfg, codec_cfg;
> +		unsigned int mask;
> +
> +		if (qcom_snd_get_dai_tdm_slots(rtd, &cpu_cfg, &codec_cfg))


qcom_snd_get_dai_tdm_slots() errors are silently ignored here and the channel count falls back to 2.
Could we distinguish the no-TDM-slot case from an actual parsing/configuration error?
This would also make invalid TDM configurations easier to debug.

Thanks,
Prasad

> +			break;
> +
> +		/* Same slot mask selection as q6tdm_set_tdm_slot() */
> +		mask = (cpu_dai->id & 0x1) ? cpu_cfg.tx_mask : cpu_cfg.rx_mask;
> +		if (mask) {
> +			channels->min = hweight32(mask);
> +			channels->max = channels->min;
> +		}
> +		break;
> +	}
>   	case TX_CODEC_DMA_TX_0:
>   	case TX_CODEC_DMA_TX_1:
>   	case TX_CODEC_DMA_TX_2: