[SRU][R][PATCH v2] ASoC: qcom: x1e80100: limit speaker volumes

[Tobias Heider]

Limit the digital gain and PA volumes to a combined -3 dB in the machine
driver to reduce the risk of speaker damage until we have active speaker
protection in place (or higher safe levels have been established).

Based on commit c481016bb4f8 ("ASoC: qcom: sc8280xp: limit speaker
volumes") which addressed the same issue on the sc8280x SoC with some
minor changes as explained below.

The Digital Volume behaves identical to sc8280x, both use the same
lpass-wsa-macro.
For PA x1e80100 machines use wsa884x amplifiers which expose a linear
scale from -9 dB to 9 dB with a 1.5 dB step size giving us
0 dB = -9 dB + 6 * 1.5 dB.

On x1e80100 there are two different speaker topologies we need to handle:
  2-Speakers: SpkrLeft, Spkr Right
  4-Speakers: WooferLeft, WooferRight, TweeterLeft, TweeterRight

Signed-off-by: Tobias Heider <tobias.heider at canonical.com>
---

- Changed in v2:
  Fixed names of Digital Volume Channels. On X1 they are prefixed with
  WSA and WSA2 (for 4 speaker configurations). Based on LKML feedback.

 sound/soc/qcom/x1e80100.c | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/sound/soc/qcom/x1e80100.c b/sound/soc/qcom/x1e80100.c
index a3f4785c4bbe..c81df41ace88 100644
--- a/sound/soc/qcom/x1e80100.c
+++ b/sound/soc/qcom/x1e80100.c
@@ -27,10 +27,29 @@ static int x1e80100_snd_init(struct snd_soc_pcm_runtime *rtd)
 {
 	struct x1e80100_snd_data *data = snd_soc_card_get_drvdata(rtd->card);
 	struct snd_soc_dai *cpu_dai = snd_soc_rtd_to_cpu(rtd, 0);
+	struct snd_soc_card *card = rtd->card;
 	struct snd_soc_jack *dp_jack = NULL;
 	int dp_pcm_id = 0;
 
 	switch (cpu_dai->id) {
+	case WSA_CODEC_DMA_RX_0:
+	case WSA_CODEC_DMA_RX_1:
+		/*
+		 * Set limit of -3 dB on Digital Volume and 0 dB on PA Volume
+		 * to reduce the risk of speaker damage until we have active
+		 * speaker protection in place.
+		 */
+		snd_soc_limit_volume(card, "WSA WSA_RX0 Digital Volume", 81);
+		snd_soc_limit_volume(card, "WSA WSA_RX1 Digital Volume", 81);
+		snd_soc_limit_volume(card, "WSA2 WSA_RX0 Digital Volume", 81);
+		snd_soc_limit_volume(card, "WSA2 WSA_RX1 Digital Volume", 81);
+		snd_soc_limit_volume(card, "SpkrLeft PA Volume", 6);
+		snd_soc_limit_volume(card, "SpkrRight PA Volume", 6);
+		snd_soc_limit_volume(card, "WooferLeft PA Volume", 6);
+		snd_soc_limit_volume(card, "TweeterLeft PA Volume", 6);
+		snd_soc_limit_volume(card, "WooferRight PA Volume", 6);
+		snd_soc_limit_volume(card, "TweeterRight PA Volume", 6);
+		break;
 	case DISPLAY_PORT_RX_0:
 		dp_pcm_id = 0;
 		dp_jack = &data->dp_jack[dp_pcm_id];
-- 
2.51.0