[PATCH v6 2/6] ASoC: sgtl5000: Improve VAG power and mute control

From: Oleksandr Suvorov
Date: Fri Jul 19 2019 - 06:05:41 EST

VAG power control is improved to fit the manual [1]. This patch fixes as
minimum one bug: if customer muxes Headphone to Line-In right after boot,
the VAG power remains off that leads to poor sound quality from line-in.

I.e. after boot:
- Connect sound source to Line-In jack;
- Connect headphone to HP jack;
- Run following commands:
$ amixer set 'Headphone' 80%
$ amixer set 'Headphone Mux' LINE_IN

Change VAG power on/off control according to the following algorithm:
- turn VAG power ON on the 1st incoming event.
- keep it ON if there is any active VAG consumer (ADC/DAC/HP/Line-In).
- turn VAG power OFF when there is the latest consumer's pre-down event
come.
- always delay after VAG power OFF to avoid pop.
- delay after VAG power ON if the initiative consumer is Line-In, this
prevents pop during line-in muxing.

According to the data sheet [1], to avoid any pops/clicks,
the outputs should be muted during input/output
routing changes.

[1] https://www.nxp.com/docs/en/data-sheet/SGTL5000.pdf

Cc: stable@xxxxxxxxxxxxxxx
Fixes: 9b34e6cc3bc2 ("ASoC: Add Freescale SGTL5000 codec support")
Signed-off-by: Oleksandr Suvorov <oleksandr.suvorov@xxxxxxxxxxx>
Reviewed-by: Marcel Ziswiler <marcel.ziswiler@xxxxxxxxxxx>
Reviewed-by: Fabio Estevam <festevam@xxxxxxxxx>

---

Changes in v6:
- Code optimization

Changes in v5:
- Improve commit message
- Add explicit stable tag

Changes in v4:
- Code optimization, simplify function signature
(thanks to Cezary Rojewski <cezary.rojewski@xxxxxxxxx> for an idea)
- CC the patch to kernel-stable
- Add a Fixes tag

Changes in v3:
- Add the reference to NXP SGTL5000 data sheet to commit message

Changes in v2:
- Fix patch formatting

sound/soc/codecs/sgtl5000.c | 226 +++++++++++++++++++++++++++++++-----
1 file changed, 195 insertions(+), 31 deletions(-)

diff --git a/sound/soc/codecs/sgtl5000.c b/sound/soc/codecs/sgtl5000.c
index a6a4748c97f9..34cc85e49003 100644
--- a/sound/soc/codecs/sgtl5000.c
+++ b/sound/soc/codecs/sgtl5000.c
@@ -31,6 +31,13 @@
#define SGTL5000_DAP_REG_OFFSET 0x0100
#define SGTL5000_MAX_REG_OFFSET 0x013A

+/* Delay for the VAG ramp up */
+#define SGTL5000_VAG_POWERUP_DELAY 500 /* ms */
+/* Delay for the VAG ramp down */
+#define SGTL5000_VAG_POWERDOWN_DELAY 500 /* ms */
+
+#define SGTL5000_OUTPUTS_MUTE (SGTL5000_HP_MUTE | SGTL5000_LINE_OUT_MUTE)
+
/* default value of sgtl5000 registers */
static const struct reg_default sgtl5000_reg_defaults[] = {
{ SGTL5000_CHIP_DIG_POWER, 0x0000 },
@@ -123,6 +130,13 @@ enum {
I2S_SCLK_STRENGTH_HIGH,
};

+enum {
+ HP_POWER_EVENT,
+ DAC_POWER_EVENT,
+ ADC_POWER_EVENT,
+ LAST_POWER_EVENT = ADC_POWER_EVENT
+};
+
/* sgtl5000 private structure in codec */
struct sgtl5000_priv {
int sysclk; /* sysclk rate */
@@ -137,8 +151,109 @@ struct sgtl5000_priv {
u8 micbias_voltage;
u8 lrclk_strength;
u8 sclk_strength;
+ u16 mute_state[LAST_POWER_EVENT + 1];
};

+static inline int hp_sel_input(struct snd_soc_component *component)
+{
+ return (snd_soc_component_read32(component, SGTL5000_CHIP_ANA_CTRL) &
+ SGTL5000_HP_SEL_MASK) >> SGTL5000_HP_SEL_SHIFT;
+}
+
+static inline u16 mute_output(struct snd_soc_component *component,
+ u16 mute_mask)
+{
+ u16 mute_reg = snd_soc_component_read32(component,
+ SGTL5000_CHIP_ANA_CTRL);
+
+ snd_soc_component_update_bits(component, SGTL5000_CHIP_ANA_CTRL,
+ mute_mask, mute_mask);
+ return mute_reg;
+}
+
+static inline void restore_output(struct snd_soc_component *component,
+ u16 mute_mask, u16 mute_reg)
+{
+ snd_soc_component_update_bits(component, SGTL5000_CHIP_ANA_CTRL,
+ mute_mask, mute_reg);
+}
+
+static void vag_power_on(struct snd_soc_component *component, u32 source)
+{
+ if (snd_soc_component_read32(component, SGTL5000_CHIP_ANA_POWER) &
+ SGTL5000_VAG_POWERUP)
+ return;
+
+ snd_soc_component_update_bits(component, SGTL5000_CHIP_ANA_POWER,
+ SGTL5000_VAG_POWERUP, SGTL5000_VAG_POWERUP);
+
+ /* When VAG powering on to get local loop from Line-In, the sleep
+ * is required to avoid loud pop.
+ */
+ if (hp_sel_input(component) == SGTL5000_HP_SEL_LINE_IN &&
+ source == HP_POWER_EVENT)
+ msleep(SGTL5000_VAG_POWERUP_DELAY);
+}
+
+static int vag_power_consumers(struct snd_soc_component *component,
+ u16 ana_pwr_reg, u32 source)
+{
+ int consumers = 0;
+
+ /* count dac/adc consumers unconditional */
+ if (ana_pwr_reg & SGTL5000_DAC_POWERUP)
+ consumers++;
+ if (ana_pwr_reg & SGTL5000_ADC_POWERUP)
+ consumers++;
+
+ /*
+ * If the event comes from HP and Line-In is selected,
+ * current action is 'DAC to be powered down'.
+ * As HP_POWERUP is not set when HP muxed to line-in,
+ * we need to keep VAG power ON.
+ */
+ if (source == HP_POWER_EVENT) {
+ if (hp_sel_input(component) == SGTL5000_HP_SEL_LINE_IN)
+ consumers++;
+ } else {
+ if (ana_pwr_reg & SGTL5000_HP_POWERUP)
+ consumers++;
+ }
+
+ return consumers;
+}
+
+static void vag_power_off(struct snd_soc_component *component, u32 source)
+{
+ u16 ana_pwr = snd_soc_component_read32(component,
+ SGTL5000_CHIP_ANA_POWER);
+
+ if (!(ana_pwr & SGTL5000_VAG_POWERUP))
+ return;
+
+ /*
+ * This function calls when any of VAG power consumers is disappearing.
+ * Thus, if there is more than one consumer at the moment, as minimum
+ * one consumer will definitely stay after the end of the current
+ * event.
+ * Don't clear VAG_POWERUP if 2 or more consumers of VAG present:
+ * - LINE_IN (for HP events) / HP (for DAC/ADC events)
+ * - DAC
+ * - ADC
+ * (the current consumer is disappearing right now)
+ */
+ if (vag_power_consumers(component, ana_pwr, source) >= 2)
+ return;
+
+ snd_soc_component_update_bits(component, SGTL5000_CHIP_ANA_POWER,
+ SGTL5000_VAG_POWERUP, 0);
+ /* In power down case, we need wait 400-1000 ms
+ * when VAG fully ramped down.
+ * As longer we wait, as smaller pop we've got.
+ */
+ msleep(SGTL5000_VAG_POWERDOWN_DELAY);
+}
+
/*
* mic_bias power on/off share the same register bits with
* output impedance of mic bias, when power on mic bias, we
@@ -170,36 +285,46 @@ static int mic_bias_event(struct snd_soc_dapm_widget *w,
return 0;
}

-/*
- * As manual described, ADC/DAC only works when VAG powerup,
- * So enabled VAG before ADC/DAC up.
- * In power down case, we need wait 400ms when vag fully ramped down.
- */
-static int power_vag_event(struct snd_soc_dapm_widget *w,
- struct snd_kcontrol *kcontrol, int event)
+static int vag_and_mute_control(struct snd_soc_component *component,
+ int event, int event_source)
{
- struct snd_soc_component *component = snd_soc_dapm_to_component(w->dapm);
- const u32 mask = SGTL5000_DAC_POWERUP | SGTL5000_ADC_POWERUP;
+ static const u16 mute_mask[] = {
+ /*
+ * Mask for HP_POWER_EVENT.
+ * Muxing Headphones have to be wrapped with mute/unmute
+ * headphones only.
+ */
+ SGTL5000_HP_MUTE,
+ /*
+ * Masks for DAC_POWER_EVENT/ADC_POWER_EVENT.
+ * Muxing DAC or ADC block have to wrapped with mute/unmute
+ * both headphones and line-out.
+ */
+ SGTL5000_OUTPUTS_MUTE,
+ SGTL5000_OUTPUTS_MUTE
+ };
+
+ struct sgtl5000_priv *sgtl5000 =
+ snd_soc_component_get_drvdata(component);

switch (event) {
- case SND_SOC_DAPM_POST_PMU:
- snd_soc_component_update_bits(component, SGTL5000_CHIP_ANA_POWER,
- SGTL5000_VAG_POWERUP, SGTL5000_VAG_POWERUP);
- msleep(400);
+ case SND_SOC_DAPM_PRE_PMU:
+ sgtl5000->mute_state[event_source] =
+ mute_output(component, mute_mask[event_source]);
+ break;
+ case SND_SOC_DAPM_POST_PMU:
+ vag_power_on(component, event_source);
+ restore_output(component, mute_mask[event_source],
+ sgtl5000->mute_state[event_source]);
break;
-
case SND_SOC_DAPM_PRE_PMD:
- /*
- * Don't clear VAG_POWERUP, when both DAC and ADC are
- * operational to prevent inadvertently starving the
- * other one of them.
- */
- if ((snd_soc_component_read32(component, SGTL5000_CHIP_ANA_POWER) &
- mask) != mask) {
- snd_soc_component_update_bits(component, SGTL5000_CHIP_ANA_POWER,
- SGTL5000_VAG_POWERUP, 0);
- msleep(400);
- }
+ sgtl5000->mute_state[event_source] =
+ mute_output(component, mute_mask[event_source]);
+ vag_power_off(component, event_source);
+ break;
+ case SND_SOC_DAPM_POST_PMD:
+ restore_output(component, mute_mask[event_source],
+ sgtl5000->mute_state[event_source]);
break;
default:
break;
@@ -208,6 +333,41 @@ static int power_vag_event(struct snd_soc_dapm_widget *w,
return 0;
}

+/*
+ * Mute Headphone when power it up/down.
+ * Control VAG power on HP power path.
+ */
+static int headphone_pga_event(struct snd_soc_dapm_widget *w,
+ struct snd_kcontrol *kcontrol, int event)
+{
+ struct snd_soc_component *component =
+ snd_soc_dapm_to_component(w->dapm);
+
+ return vag_and_mute_control(component, event, HP_POWER_EVENT);
+}
+
+/* As manual describes, ADC/DAC powering up/down requires
+ * to mute outputs to avoid pops.
+ * Control VAG power on ADC/DAC power path.
+ */
+static int adc_updown_depop(struct snd_soc_dapm_widget *w,
+ struct snd_kcontrol *kcontrol, int event)
+{
+ struct snd_soc_component *component =
+ snd_soc_dapm_to_component(w->dapm);
+
+ return vag_and_mute_control(component, event, ADC_POWER_EVENT);
+}
+
+static int dac_updown_depop(struct snd_soc_dapm_widget *w,
+ struct snd_kcontrol *kcontrol, int event)
+{
+ struct snd_soc_component *component =
+ snd_soc_dapm_to_component(w->dapm);
+
+ return vag_and_mute_control(component, event, DAC_POWER_EVENT);
+}
+
/* input sources for ADC */
static const char *adc_mux_text[] = {
"MIC_IN", "LINE_IN"
@@ -280,7 +440,10 @@ static const struct snd_soc_dapm_widget sgtl5000_dapm_widgets[] = {
mic_bias_event,
SND_SOC_DAPM_POST_PMU | SND_SOC_DAPM_PRE_PMD),

- SND_SOC_DAPM_PGA("HP", SGTL5000_CHIP_ANA_POWER, 4, 0, NULL, 0),
+ SND_SOC_DAPM_PGA_E("HP", SGTL5000_CHIP_ANA_POWER, 4, 0, NULL, 0,
+ headphone_pga_event,
+ SND_SOC_DAPM_PRE_POST_PMU |
+ SND_SOC_DAPM_PRE_POST_PMD),
SND_SOC_DAPM_PGA("LO", SGTL5000_CHIP_ANA_POWER, 0, 0, NULL, 0),

SND_SOC_DAPM_MUX("Capture Mux", SND_SOC_NOPM, 0, 0, &adc_mux),
@@ -301,11 +464,12 @@ static const struct snd_soc_dapm_widget sgtl5000_dapm_widgets[] = {
0, SGTL5000_CHIP_DIG_POWER,
1, 0),

- SND_SOC_DAPM_ADC("ADC", "Capture", SGTL5000_CHIP_ANA_POWER, 1, 0),
- SND_SOC_DAPM_DAC("DAC", "Playback", SGTL5000_CHIP_ANA_POWER, 3, 0),
-
- SND_SOC_DAPM_PRE("VAG_POWER_PRE", power_vag_event),
- SND_SOC_DAPM_POST("VAG_POWER_POST", power_vag_event),
+ SND_SOC_DAPM_ADC_E("ADC", "Capture", SGTL5000_CHIP_ANA_POWER, 1, 0,
+ adc_updown_depop, SND_SOC_DAPM_PRE_POST_PMU |
+ SND_SOC_DAPM_PRE_POST_PMD),
+ SND_SOC_DAPM_DAC_E("DAC", "Playback", SGTL5000_CHIP_ANA_POWER, 3, 0,
+ dac_updown_depop, SND_SOC_DAPM_PRE_POST_PMU |
+ SND_SOC_DAPM_PRE_POST_PMD),
};

/* routes for sgtl5000 */
--
2.20.1