ASoC: Optimise WM8904 output stage power control

Handle the output PGAs as part of the output powerup since they can
never be powered separately and reorder things so that we remove the
output shorts after both line and headphone outputs have been brought
up, minimising the opportunity for any issues.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Liam Girdwood <lrg@slimlogic.co.uk>

sound/soc/codecs/wm8904.c

@@ -979,6 +979,7 @@ static int out_pga_event(struct snd_soc_dapm_widget *w,
 	int dcs_l, dcs_r;
 	int dcs_l_reg, dcs_r_reg;
 	int timeout;
+	int pwr_reg;
 
 	/* This code is shared between HP and LINEOUT; we do all our
 	 * power management in stereo pairs to avoid latency issues so
@@ -988,6 +989,7 @@ static int out_pga_event(struct snd_soc_dapm_widget *w,
 
 	switch (reg) {
 	case WM8904_ANALOGUE_HP_0:
+		pwr_reg = WM8904_POWER_MANAGEMENT_2;
 		dcs_mask = WM8904_DCS_ENA_CHAN_0 | WM8904_DCS_ENA_CHAN_1;
 		dcs_r_reg = WM8904_DC_SERVO_8;
 		dcs_l_reg = WM8904_DC_SERVO_9;
@@ -995,6 +997,7 @@ static int out_pga_event(struct snd_soc_dapm_widget *w,
 		dcs_r = 1;
 		break;
 	case WM8904_ANALOGUE_LINEOUT_0:
+		pwr_reg = WM8904_POWER_MANAGEMENT_3;
 		dcs_mask = WM8904_DCS_ENA_CHAN_2 | WM8904_DCS_ENA_CHAN_3;
 		dcs_r_reg = WM8904_DC_SERVO_6;
 		dcs_l_reg = WM8904_DC_SERVO_7;
@@ -1007,12 +1010,18 @@ static int out_pga_event(struct snd_soc_dapm_widget *w,
 	}
 
 	switch (event) {
-	case SND_SOC_DAPM_POST_PMU:
+	case SND_SOC_DAPM_PRE_PMU:
+		/* Power on the PGAs */
+		snd_soc_update_bits(codec, pwr_reg,
+				    WM8904_HPL_PGA_ENA | WM8904_HPR_PGA_ENA,
+				    WM8904_HPL_PGA_ENA | WM8904_HPR_PGA_ENA);
+
 		/* Power on the amplifier */
 		snd_soc_update_bits(codec, reg,
 				    WM8904_HPL_ENA | WM8904_HPR_ENA,
 				    WM8904_HPL_ENA | WM8904_HPR_ENA);
 
+
 		/* Enable the first stage */
 		snd_soc_update_bits(codec, reg,
 				    WM8904_HPL_ENA_DLY | WM8904_HPR_ENA_DLY,
@@ -1064,7 +1073,9 @@ static int out_pga_event(struct snd_soc_dapm_widget *w,
 		snd_soc_update_bits(codec, reg,
 				    WM8904_HPL_ENA_OUTP | WM8904_HPR_ENA_OUTP,
 				    WM8904_HPL_ENA_OUTP | WM8904_HPR_ENA_OUTP);
+		break;
 
+	case SND_SOC_DAPM_POST_PMU:
 		/* Unshort the output itself */
 		snd_soc_update_bits(codec, reg,
 				    WM8904_HPL_RMV_SHORT |
@@ -1079,7 +1090,9 @@ static int out_pga_event(struct snd_soc_dapm_widget *w,
 		snd_soc_update_bits(codec, reg,
 				    WM8904_HPL_RMV_SHORT |
 				    WM8904_HPR_RMV_SHORT, 0);
+		break;
 
+	case SND_SOC_DAPM_POST_PMD:
 		/* Cache the DC servo configuration; this will be
 		 * invalidated if we change the configuration. */
 		wm8904->dcs_state[dcs_l] = snd_soc_read(codec, dcs_l_reg);
@@ -1094,6 +1107,11 @@ static int out_pga_event(struct snd_soc_dapm_widget *w,
 				    WM8904_HPL_ENA_DLY | WM8904_HPR_ENA_DLY |
 				    WM8904_HPL_ENA_OUTP | WM8904_HPR_ENA_OUTP,
 				    0);
+
+		/* PGAs too */
+		snd_soc_update_bits(codec, pwr_reg,
+				    WM8904_HPL_PGA_ENA | WM8904_HPR_PGA_ENA,
+				    0);
 		break;
 	}
 
@@ -1212,18 +1230,20 @@ SND_SOC_DAPM_DAC("DACR", NULL, WM8904_POWER_MANAGEMENT_6, 2, 0),
 SND_SOC_DAPM_SUPPLY("Charge pump", WM8904_CHARGE_PUMP_0, 0, 0, cp_event,
 		    SND_SOC_DAPM_POST_PMU),
 
-SND_SOC_DAPM_PGA("HPL PGA", WM8904_POWER_MANAGEMENT_2, 1, 0, NULL, 0),
-SND_SOC_DAPM_PGA("HPR PGA", WM8904_POWER_MANAGEMENT_2, 0, 0, NULL, 0),
+SND_SOC_DAPM_PGA("HPL PGA", SND_SOC_NOPM, 1, 0, NULL, 0),
+SND_SOC_DAPM_PGA("HPR PGA", SND_SOC_NOPM, 0, 0, NULL, 0),
 
-SND_SOC_DAPM_PGA("LINEL PGA", WM8904_POWER_MANAGEMENT_3, 1, 0, NULL, 0),
-SND_SOC_DAPM_PGA("LINER PGA", WM8904_POWER_MANAGEMENT_3, 0, 0, NULL, 0),
+SND_SOC_DAPM_PGA("LINEL PGA", SND_SOC_NOPM, 1, 0, NULL, 0),
+SND_SOC_DAPM_PGA("LINER PGA", SND_SOC_NOPM, 0, 0, NULL, 0),
 
 SND_SOC_DAPM_PGA_E("Headphone Output", SND_SOC_NOPM, WM8904_ANALOGUE_HP_0,
 		   0, NULL, 0, out_pga_event,
-		   SND_SOC_DAPM_POST_PMU | SND_SOC_DAPM_PRE_PMD),
+		   SND_SOC_DAPM_PRE_PMU | SND_SOC_DAPM_POST_PMU |
+		   SND_SOC_DAPM_PRE_PMD | SND_SOC_DAPM_POST_PMD),
 SND_SOC_DAPM_PGA_E("Line Output", SND_SOC_NOPM, WM8904_ANALOGUE_LINEOUT_0,
 		   0, NULL, 0, out_pga_event,
-		   SND_SOC_DAPM_POST_PMU | SND_SOC_DAPM_PRE_PMD),
+		   SND_SOC_DAPM_PRE_PMU | SND_SOC_DAPM_POST_PMU |
+		   SND_SOC_DAPM_PRE_PMD | SND_SOC_DAPM_POST_PMD),
 
 SND_SOC_DAPM_OUTPUT("HPOUTL"),
 SND_SOC_DAPM_OUTPUT("HPOUTR"),