ASoC: cs42l42: Add bitclock frequency argument to cs42l42_pll_config()

Clean up the handling of bitclock frequency by keeping all the logic
in cs42l42_pcm_hw_params(), which then simply passes the frequency as
an argument to cs42l42_pll_config().

The previous code had become clunky as a legacy of earlier versions of
the clock handling. The logic was split across cs42l42_pcm_hw_params()
and cs42l42_pll_config(), with the params-derived bclk stashed in
struct cs42l42_private only to pass it to cs42l42_pll_config().
Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Signed-off-by: Martin Povišer <povik+lin@cutebit.org>
Link: https://lore.kernel.org/r/20220915094444.11434-3-povik+lin@cutebit.orgSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/codecs/cs42l42.c

@@ -647,18 +647,12 @@ static const struct cs42l42_pll_params pll_ratio_table[] = {
 	{ 24576000, 1, 0x03, 0x40, 0x000000, 0x03, 0x10, 12288000, 128, 1}
 };
 
-static int cs42l42_pll_config(struct snd_soc_component *component)
+static int cs42l42_pll_config(struct snd_soc_component *component, unsigned int clk)
 {
 	struct cs42l42_private *cs42l42 = snd_soc_component_get_drvdata(component);
 	int i;
-	u32 clk;
 	u32 fsync;
 
-	if (!cs42l42->sclk)
-		clk = cs42l42->bclk;
-	else
-		clk = cs42l42->sclk;
-
 	/* Don't reconfigure if there is an audio stream running */
 	if (cs42l42->stream_use) {
 		if (pll_ratio_table[cs42l42->pll_config].sclk == clk)
@@ -895,19 +889,25 @@ static int cs42l42_pcm_hw_params(struct snd_pcm_substream *substream,
 	unsigned int width = (params_width(params) / 8) - 1;
 	unsigned int slot_width = 0;
 	unsigned int val = 0;
+	unsigned int bclk;
 	int ret;
 
 	cs42l42->srate = params_rate(params);
 
-	/*
-	 * Assume 24-bit samples are in 32-bit slots, to prevent SCLK being
-	 * more than assumed (which would result in overclocking).
-	 */
-	if (params_width(params) == 24)
-		slot_width = 32;
+	if (cs42l42->sclk) {
+		/* machine driver has set the SCLK */
+		bclk = cs42l42->sclk;
+	} else {
+		/*
+		 * Assume 24-bit samples are in 32-bit slots, to prevent SCLK being
+		 * more than assumed (which would result in overclocking).
+		 */
+		if (params_width(params) == 24)
+			slot_width = 32;
 
-	/* I2S frame always has multiple of 2 channels */
-	cs42l42->bclk = snd_soc_tdm_params_to_bclk(params, slot_width, 0, 2);
+		/* I2S frame always has multiple of 2 channels */
+		bclk = snd_soc_tdm_params_to_bclk(params, slot_width, 0, 2);
+	}
 
 	switch (substream->stream) {
 	case SNDRV_PCM_STREAM_CAPTURE:
@@ -947,7 +947,7 @@ static int cs42l42_pcm_hw_params(struct snd_pcm_substream *substream,
 		break;
 	}
 
-	ret = cs42l42_pll_config(component);
+	ret = cs42l42_pll_config(component, bclk);
 	if (ret)
 		return ret;
 

sound/soc/codecs/cs42l42.h

@@ -30,7 +30,6 @@ struct  cs42l42_private {
 	struct snd_soc_jack *jack;
 	struct mutex irq_lock;
 	int pll_config;
-	int bclk;
 	u32 sclk;
 	u32 srate;
 	u8 plug_state;