ASoC: da7219: Fix pole orientation detection on certain headsets

It has been recently found that certain 'active' headsets can
be mis-detected as OMTP instead of CTIA, causing obvious issus
with audio quality. This relates to increased resistances which
negatively impacts the pole detection circuitry within the device.

To counter this, ground switches on both headphone channels are
available to enable/disable and these allow for the detection
process to operate as intended, even with active headsets. This
commit adds control of the ground switches to the AAD logic.
Signed-off-by: Adam Thomson <DLG-Adam.Thomson.Opensource@dm.renesas.com>
Link: https://lore.kernel.org/r/e0a627725c189dd50d6ce24571aed87fe2597395.1653916368.git.DLG-Adam.Thomson.Opensource@dm.renesas.comSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/codecs/da7219-aad.c

@@ -60,6 +60,9 @@ static void da7219_aad_btn_det_work(struct work_struct *work)
 	bool micbias_up = false;
 	int retries = 0;
 
+	/* Disable ground switch */
+	snd_soc_component_update_bits(component, 0xFB, 0x01, 0x00);
+
 	/* Drive headphones/lineout */
 	snd_soc_component_update_bits(component, DA7219_HP_L_CTRL,
 			    DA7219_HP_L_AMP_OE_MASK,
@@ -153,6 +156,9 @@ static void da7219_aad_hptest_work(struct work_struct *work)
 		tonegen_freq_hptest = cpu_to_le16(DA7219_AAD_HPTEST_RAMP_FREQ_INT_OSC);
 	}
 
+	/* Disable ground switch */
+	snd_soc_component_update_bits(component, 0xFB, 0x01, 0x00);
+
 	/* Ensure gain ramping at fastest rate */
 	gain_ramp_ctrl = snd_soc_component_read(component, DA7219_GAIN_RAMP_CTRL);
 	snd_soc_component_write(component, DA7219_GAIN_RAMP_CTRL, DA7219_GAIN_RAMP_RATE_X8);
@@ -444,6 +450,9 @@ static irqreturn_t da7219_aad_irq_thread(int irq, void *data)
 			snd_soc_dapm_disable_pin(dapm, "Mic Bias");
 			snd_soc_dapm_sync(dapm);
 
+			/* Enable ground switch */
+			snd_soc_component_update_bits(component, 0xFB, 0x01, 0x01);
+
 			/* Cancel any pending work */
 			cancel_work_sync(&da7219_aad->btn_det_work);
 			cancel_work_sync(&da7219_aad->hptest_work);
@@ -899,6 +908,9 @@ int da7219_aad_init(struct snd_soc_component *component)
 	snd_soc_component_update_bits(component, DA7219_ACCDET_CONFIG_1,
 			    DA7219_BUTTON_CONFIG_MASK, 0);
 
+	/* Enable ground switch */
+	snd_soc_component_update_bits(component, 0xFB, 0x01, 0x01);
+
 	INIT_WORK(&da7219_aad->btn_det_work, da7219_aad_btn_det_work);
 	INIT_WORK(&da7219_aad->hptest_work, da7219_aad_hptest_work);