OpenWrt – Rev 1
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From 60e945e3c654aae415773a500b021914461ae928 Mon Sep 17 00:00:00 2001
From: Matthias Reichl <hias@horus.com>
Date: Thu, 22 Feb 2018 11:55:06 +0100
Subject: [PATCH 229/454] ASoC: pcm512x: implement set_tdm_slot interface
PCM512x can accept data padded with additional BCLK cycles
but the driver currently lacks an interface to configure this.
This leads to the problem that S24_LE format in master mode
can result in non-integer clock divisors and pcm512x running
at a rather off rate.
For example 48kHz with 48fs BCLK and SCLK at 24.576MHz uses
a divisor of 10 (rounded down from 10.6666) and results in a
51.2kHz LRCLK. With 64fs BCLK a divisor of 8 is used and
LRCLK runs at exactly 48kHz.
Fix this by providing a minimal set_tdm_slot implementation
so machine drivers can optionally configure custom BCLK ratios.
Signed-off-by: Matthias Reichl <hias@horus.com>
---
sound/soc/codecs/pcm512x.c | 28 +++++++++++++++++++++++++++-
1 file changed, 27 insertions(+), 1 deletion(-)
--- a/sound/soc/codecs/pcm512x.c
+++ b/sound/soc/codecs/pcm512x.c
@@ -53,6 +53,7 @@ struct pcm512x_priv {
unsigned long overclock_pll;
unsigned long overclock_dac;
unsigned long overclock_dsp;
+ int lrclk_div;
};
/*
@@ -851,7 +852,10 @@ static int pcm512x_set_dividers(struct s
int fssp;
int gpio;
- lrclk_div = snd_soc_params_to_frame_size(params);
+ if (pcm512x->lrclk_div)
+ lrclk_div = pcm512x->lrclk_div;
+ else
+ lrclk_div = snd_soc_params_to_frame_size(params);
if (lrclk_div == 0) {
dev_err(dev, "No LRCLK?\n");
return -EINVAL;
@@ -1319,10 +1323,32 @@ static int pcm512x_set_fmt(struct snd_so
return 0;
}
+static int pcm512x_set_tdm_slot(struct snd_soc_dai *dai,
+ unsigned int tx_mask, unsigned int rx_mask,
+ int slots, int width)
+{
+ struct snd_soc_codec *codec = dai->codec;
+ struct pcm512x_priv *pcm512x = snd_soc_codec_get_drvdata(codec);
+
+ switch (slots) {
+ case 0:
+ pcm512x->lrclk_div = 0;
+ return 0;
+ case 2:
+ if (tx_mask != 0x03 || rx_mask != 0x03)
+ return -EINVAL;
+ pcm512x->lrclk_div = slots * width;
+ return 0;
+ default:
+ return -EINVAL;
+ }
+}
+
static const struct snd_soc_dai_ops pcm512x_dai_ops = {
.startup = pcm512x_dai_startup,
.hw_params = pcm512x_hw_params,
.set_fmt = pcm512x_set_fmt,
+ .set_tdm_slot = pcm512x_set_tdm_slot,
};
static struct snd_soc_dai_driver pcm512x_dai = {