ASoC: codec: wcd-mbhc-v2: add support when connected behind an USB-C audio mux

When the WCD codec is connected behind an USB-C audio mux,
plug/unplug events, clock control, pull-up and threshold are
different.
Add a typec_analog_mux config enabling those changes and add
two callbacks to trigger plug/unplug events from USB-C events.
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://msgid.link/r/20231219-topic-sm8650-upstream-wcd939x-codec-v4-3-1c3bbff2d7ab@linaro.orgSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/codecs/wcd-mbhc-v2.c

@@ -16,6 +16,7 @@
 #define HS_DETECT_PLUG_TIME_MS		(3 * 1000)
 #define MBHC_BUTTON_PRESS_THRESHOLD_MIN	250
 #define GND_MIC_SWAP_THRESHOLD		4
+#define GND_MIC_USBC_SWAP_THRESHOLD	2
 #define WCD_FAKE_REMOVAL_MIN_PERIOD_MS	100
 #define HPHL_CROSS_CONN_THRESHOLD	100
 #define HS_VREF_MIN_VAL			1400
@@ -52,12 +53,15 @@ struct wcd_mbhc {
 	struct wcd_mbhc_field *fields;
 	/* Delayed work to report long button press */
 	struct delayed_work mbhc_btn_dwork;
+	/* Work to handle plug report */
+	struct work_struct mbhc_plug_detect_work;
 	/* Work to correct accessory type */
 	struct work_struct correct_plug_swch;
 	struct mutex lock;
 	int buttons_pressed;
 	u32 hph_status; /* track headhpone status */
 	u8 current_plug;
+	unsigned int swap_thr;
 	bool is_btn_press;
 	bool in_swch_irq_handler;
 	bool hs_detect_work_stop;
@@ -506,14 +510,13 @@ static void wcd_mbhc_adc_detect_plug_type(struct wcd_mbhc *mbhc)
 	}
 }
 
-static irqreturn_t wcd_mbhc_mech_plug_detect_irq(int irq, void *data)
+static void mbhc_plug_detect_fn(struct work_struct *work)
 {
-	struct snd_soc_component *component;
+	struct wcd_mbhc *mbhc = container_of(work, struct wcd_mbhc, mbhc_plug_detect_work);
+	struct snd_soc_component *component = mbhc->component;
 	enum snd_jack_types jack_type;
-	struct wcd_mbhc *mbhc = data;
 	bool detection_type;
 
-	component = mbhc->component;
 	mutex_lock(&mbhc->lock);
 
 	mbhc->in_swch_irq_handler = true;
@@ -576,9 +579,51 @@ static irqreturn_t wcd_mbhc_mech_plug_detect_irq(int irq, void *data)
 exit:
 	mbhc->in_swch_irq_handler = false;
 	mutex_unlock(&mbhc->lock);
+}
+
+static irqreturn_t wcd_mbhc_mech_plug_detect_irq(int irq, void *data)
+{
+	struct wcd_mbhc *mbhc = data;
+
+	if (!mbhc->cfg->typec_analog_mux)
+		schedule_work(&mbhc->mbhc_plug_detect_work);
+
 	return IRQ_HANDLED;
 }
 
+int wcd_mbhc_typec_report_unplug(struct wcd_mbhc *mbhc)
+{
+
+	if (!mbhc || !mbhc->cfg->typec_analog_mux)
+		return -EINVAL;
+
+	if (mbhc->mbhc_cb->clk_setup)
+		mbhc->mbhc_cb->clk_setup(mbhc->component, false);
+
+	wcd_mbhc_write_field(mbhc, WCD_MBHC_L_DET_EN, 0);
+	wcd_mbhc_write_field(mbhc, WCD_MBHC_MECH_DETECTION_TYPE, 0);
+
+	schedule_work(&mbhc->mbhc_plug_detect_work);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(wcd_mbhc_typec_report_unplug);
+
+int wcd_mbhc_typec_report_plug(struct wcd_mbhc *mbhc)
+{
+	if (!mbhc || !mbhc->cfg->typec_analog_mux)
+		return -EINVAL;
+
+	if (mbhc->mbhc_cb->clk_setup)
+		mbhc->mbhc_cb->clk_setup(mbhc->component, true);
+	wcd_mbhc_write_field(mbhc, WCD_MBHC_L_DET_EN, 1);
+
+	schedule_work(&mbhc->mbhc_plug_detect_work);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(wcd_mbhc_typec_report_plug);
+
 static int wcd_mbhc_get_button_mask(struct wcd_mbhc *mbhc)
 {
 	int mask = 0;
@@ -725,14 +770,23 @@ static int wcd_mbhc_initialise(struct wcd_mbhc *mbhc)
 
 	mutex_lock(&mbhc->lock);
 
-	/* enable HS detection */
+	if (mbhc->cfg->typec_analog_mux)
+		mbhc->swap_thr = GND_MIC_USBC_SWAP_THRESHOLD;
+	else
+		mbhc->swap_thr = GND_MIC_SWAP_THRESHOLD;
+
+	/* setup HS detection */
 	if (mbhc->mbhc_cb->hph_pull_up_control_v2)
 		mbhc->mbhc_cb->hph_pull_up_control_v2(component,
-						      HS_PULLUP_I_DEFAULT);
+				mbhc->cfg->typec_analog_mux ?
+					HS_PULLUP_I_OFF : HS_PULLUP_I_DEFAULT);
 	else if (mbhc->mbhc_cb->hph_pull_up_control)
-		mbhc->mbhc_cb->hph_pull_up_control(component, I_DEFAULT);
+		mbhc->mbhc_cb->hph_pull_up_control(component,
+				mbhc->cfg->typec_analog_mux ?
+					I_OFF : I_DEFAULT);
 	else
-		wcd_mbhc_write_field(mbhc, WCD_MBHC_HS_L_DET_PULL_UP_CTRL, 3);
+		wcd_mbhc_write_field(mbhc, WCD_MBHC_HS_L_DET_PULL_UP_CTRL,
+				mbhc->cfg->typec_analog_mux ? 0 : 3);
 
 	wcd_mbhc_write_field(mbhc, WCD_MBHC_HPHL_PLUG_TYPE, mbhc->cfg->hphl_swh);
 	wcd_mbhc_write_field(mbhc, WCD_MBHC_GND_PLUG_TYPE, mbhc->cfg->gnd_swh);
@@ -741,10 +795,18 @@ static int wcd_mbhc_initialise(struct wcd_mbhc *mbhc)
 		mbhc->mbhc_cb->mbhc_gnd_det_ctrl(component, true);
 	wcd_mbhc_write_field(mbhc, WCD_MBHC_HS_L_DET_PULL_UP_COMP_CTRL, 1);
 
-	wcd_mbhc_write_field(mbhc, WCD_MBHC_L_DET_EN, 1);
+	/* Plug detect is triggered manually if analog goes through USBCC */
+	if (mbhc->cfg->typec_analog_mux)
+		wcd_mbhc_write_field(mbhc, WCD_MBHC_L_DET_EN, 0);
+	else
+		wcd_mbhc_write_field(mbhc, WCD_MBHC_L_DET_EN, 1);
 
-	/* Insertion debounce set to 96ms */
-	wcd_mbhc_write_field(mbhc, WCD_MBHC_INSREM_DBNC, 6);
+	if (mbhc->cfg->typec_analog_mux)
+		/* Insertion debounce set to 48ms */
+		wcd_mbhc_write_field(mbhc, WCD_MBHC_INSREM_DBNC, 4);
+	else
+		/* Insertion debounce set to 96ms */
+		wcd_mbhc_write_field(mbhc, WCD_MBHC_INSREM_DBNC, 6);
 
 	/* Button Debounce set to 16ms */
 	wcd_mbhc_write_field(mbhc, WCD_MBHC_BTN_DBNC, 2);
@@ -753,7 +815,8 @@ static int wcd_mbhc_initialise(struct wcd_mbhc *mbhc)
 	mbhc->mbhc_cb->mbhc_bias(component, true);
 	/* enable MBHC clock */
 	if (mbhc->mbhc_cb->clk_setup)
-		mbhc->mbhc_cb->clk_setup(component, true);
+		mbhc->mbhc_cb->clk_setup(component,
+				mbhc->cfg->typec_analog_mux ? false : true);
 
 	/* program HS_VREF value */
 	wcd_program_hs_vref(mbhc);
@@ -1115,7 +1178,7 @@ static void wcd_correct_swch_plug(struct work_struct *work)
 	do {
 		cross_conn = wcd_check_cross_conn(mbhc);
 		try++;
-	} while (try < GND_MIC_SWAP_THRESHOLD);
+	} while (try < mbhc->swap_thr);
 
 	if (cross_conn > 0) {
 		plug_type = MBHC_PLUG_TYPE_GND_MIC_SWAP;
@@ -1183,7 +1246,7 @@ static void wcd_correct_swch_plug(struct work_struct *work)
 			cross_conn = wcd_check_cross_conn(mbhc);
 			if (cross_conn > 0) { /* cross-connection */
 				pt_gnd_mic_swap_cnt++;
-				if (pt_gnd_mic_swap_cnt < GND_MIC_SWAP_THRESHOLD)
+				if (pt_gnd_mic_swap_cnt < mbhc->swap_thr)
 					continue;
 				else
 					plug_type = MBHC_PLUG_TYPE_GND_MIC_SWAP;
@@ -1194,7 +1257,7 @@ static void wcd_correct_swch_plug(struct work_struct *work)
 			} else /* Error if (cross_conn < 0) */
 				continue;
 
-			if (pt_gnd_mic_swap_cnt == GND_MIC_SWAP_THRESHOLD) {
+			if (pt_gnd_mic_swap_cnt == mbhc->swap_thr) {
 				/* US_EU gpio present, flip switch */
 				if (mbhc->cfg->swap_gnd_mic) {
 					if (mbhc->cfg->swap_gnd_mic(component, true))
@@ -1473,6 +1536,7 @@ struct wcd_mbhc *wcd_mbhc_init(struct snd_soc_component *component,
 	mutex_init(&mbhc->lock);
 
 	INIT_WORK(&mbhc->correct_plug_swch, wcd_correct_swch_plug);
+	INIT_WORK(&mbhc->mbhc_plug_detect_work, mbhc_plug_detect_fn);
 
 	ret = request_threaded_irq(mbhc->intr_ids->mbhc_sw_intr, NULL,
 					wcd_mbhc_mech_plug_detect_irq,
@@ -1562,6 +1626,7 @@ void wcd_mbhc_deinit(struct wcd_mbhc *mbhc)
 
 	mutex_lock(&mbhc->lock);
 	wcd_cancel_hs_detect_plug(mbhc,	&mbhc->correct_plug_swch);
+	cancel_work_sync(&mbhc->mbhc_plug_detect_work);
 	mutex_unlock(&mbhc->lock);
 
 	kfree(mbhc);

sound/soc/codecs/wcd-mbhc-v2.h

@@ -193,6 +193,7 @@ struct wcd_mbhc_config {
 	int v_hs_max;
 	int num_btn;
 	bool mono_stero_detection;
+	bool typec_analog_mux;
 	bool (*swap_gnd_mic)(struct snd_soc_component *component, bool active);
 	bool hs_ext_micbias;
 	bool gnd_det_en;
@@ -273,6 +274,8 @@ int wcd_mbhc_start(struct wcd_mbhc *mbhc, struct wcd_mbhc_config *mbhc_cfg,
 void wcd_mbhc_stop(struct wcd_mbhc *mbhc);
 void wcd_mbhc_set_hph_type(struct wcd_mbhc *mbhc, int hph_type);
 int wcd_mbhc_get_hph_type(struct wcd_mbhc *mbhc);
+int wcd_mbhc_typec_report_plug(struct wcd_mbhc *mbhc);
+int wcd_mbhc_typec_report_unplug(struct wcd_mbhc *mbhc);
 struct wcd_mbhc *wcd_mbhc_init(struct snd_soc_component *component,
 		      const struct wcd_mbhc_cb *mbhc_cb,
 		      const struct wcd_mbhc_intr *mbhc_cdc_intr_ids,