ASoC: nau8822: Add operation for internal PLL off and on

We tried to enable the audio on an imx6sx EVB with the codec nau8822,
after setting the internal PLL fractional parameters, the audio still
couldn't work and the there was no sdma irq at all.

After checking with the section "8.1.1 Phase Locked Loop (PLL) Design
Example" of "NAU88C22 Datasheet Rev 0.6", we found we need to
turn off the PLL before programming fractional parameters and turn on
the PLL after programming.

After this change, the audio driver could record and play sound and
the sdma's irq is triggered when playing or recording.

Cc: David Lin <ctlin0@nuvoton.com>
Cc: John Hsu <kchsu0@nuvoton.com>
Cc: Seven Li <wtli@nuvoton.com>
Signed-off-by: Hui Wang <hui.wang@canonical.com>
Link: https://lore.kernel.org/r/20220530040151.95221-2-hui.wang@canonical.com
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/codecs/nau8822.c

@@ -740,6 +740,8 @@ static int nau8822_set_pll(struct snd_soc_dai *dai, int pll_id, int source,
 		pll_param->pll_int, pll_param->pll_frac,
 		pll_param->mclk_scaler, pll_param->pre_factor);
 
+	snd_soc_component_update_bits(component,
+		NAU8822_REG_POWER_MANAGEMENT_1, NAU8822_PLL_EN_MASK, NAU8822_PLL_OFF);
 	snd_soc_component_update_bits(component,
 		NAU8822_REG_PLL_N, NAU8822_PLLMCLK_DIV2 | NAU8822_PLLN_MASK,
 		(pll_param->pre_factor ? NAU8822_PLLMCLK_DIV2 : 0) |
@@ -757,6 +759,8 @@ static int nau8822_set_pll(struct snd_soc_dai *dai, int pll_id, int source,
 		pll_param->mclk_scaler << NAU8822_MCLKSEL_SFT);
 	snd_soc_component_update_bits(component,
 		NAU8822_REG_CLOCKING, NAU8822_CLKM_MASK, NAU8822_CLKM_PLL);
+	snd_soc_component_update_bits(component,
+		NAU8822_REG_POWER_MANAGEMENT_1, NAU8822_PLL_EN_MASK, NAU8822_PLL_ON);
 
 	return 0;
 }

sound/soc/codecs/nau8822.h

@@ -90,6 +90,9 @@
 #define NAU8822_REFIMP_3K			0x3
 #define NAU8822_IOBUF_EN			(0x1 << 2)
 #define NAU8822_ABIAS_EN			(0x1 << 3)
+#define NAU8822_PLL_EN_MASK			(0x1 << 5)
+#define NAU8822_PLL_ON				(0x1 << 5)
+#define NAU8822_PLL_OFF				(0x0 << 5)
 
 /* NAU8822_REG_AUDIO_INTERFACE (0x4) */
 #define NAU8822_AIFMT_MASK			(0x3 << 3)