[PATCH 0/2] ASoC: codecs: wcd937x: add USB Type-C analog audio mux support

[PATCH 0/2] ASoC: codecs: wcd937x: add USB Type-C analog audio mux support

[Val Packett]

Currently only wcd939x has support for USB-C SBU audio in mainline, but the
older WCD codecs can do the same thing 939x does with USBSS, with an
external 3rd party mux instead. This series adds support for that based on
wcd939x code.

Tested with the FSA4480 (with the [1] series) on sm7325-motorola-dubai.

[1]: https://lore.kernel.org/all/20261018225906.1265299-1-val@packett.cool/

Thanks,
~val

---

Val Packett (2):
  ASoC: dt-bindings: qcom,wcd937x: Add USB-C graph properties
  ASoC: codecs: wcd937x: add USB Type-C analog audio mux support

 .../bindings/sound/qcom,wcd937x.yaml          |  15 ++
 sound/soc/codecs/wcd937x.c                    | 151 +++++++++++++++++-
 2 files changed, 163 insertions(+), 3 deletions(-)

-- 
2.55.0

[PATCH 1/2] ASoC: dt-bindings: qcom,wcd937x: Add USB-C graph properties

[Val Packett]

This codec can be used with a USB-C SBU mux to support analog headphone
adapters. Describe the mode-switch, orientation-switch and port
properties similarly to wcd939x.

Signed-off-by: Val Packett <val@packett.cool>
---
 .../devicetree/bindings/sound/qcom,wcd937x.yaml   | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/Documentation/devicetree/bindings/sound/qcom,wcd937x.yaml b/Documentation/devicetree/bindings/sound/qcom,wcd937x.yaml
index f94203798f24..f15b9a9d90b1 100644
--- a/Documentation/devicetree/bindings/sound/qcom,wcd937x.yaml
+++ b/Documentation/devicetree/bindings/sound/qcom,wcd937x.yaml
@@ -25,6 +25,21 @@ properties:
           - const: qcom,wcd9375-codec
           - const: qcom,wcd9370-codec
 
+  mode-switch:
+    description: Flag the port as possible handler of altmode switching
+    type: boolean
+
+  orientation-switch:
+    description: Flag the port as possible handler of orientation switching
+    type: boolean
+
+  port:
+    $ref: /schemas/graph.yaml#/properties/port
+    description:
+      A port node to link the WCD937x Codec node to an external USB-C MUX IC for
+      handling altmode muxing and orientation switching to detect and enable
+      Audio Accessory Mode.
+
   vdd-px-supply:
     description: A reference to the 1.8V I/O supply
 
-- 
2.55.0

[PATCH 2/2] ASoC: codecs: wcd937x: add USB Type-C analog audio mux support

[Val Packett]

On mobile devices, this codec is frequently paired with a USB-C SBU mux
like the FSA4480 to support analog headphone adapters. To support this,
register the codec in the Type-C graph whenever one is present in the
device tree, handle the hotplug notifications and report detected GND-MIC
pin swap back to the external mux as Type-C orientation.

Based on code from the wcd939x driver.

Signed-off-by: Val Packett <val@packett.cool>
---
 sound/soc/codecs/wcd937x.c | 151 ++++++++++++++++++++++++++++++++++++-
 1 file changed, 148 insertions(+), 3 deletions(-)

diff --git a/sound/soc/codecs/wcd937x.c b/sound/soc/codecs/wcd937x.c
index 7ffbb445f8ac..770f5925e89f 100644
--- a/sound/soc/codecs/wcd937x.c
+++ b/sound/soc/codecs/wcd937x.c
@@ -8,12 +8,15 @@
 #include <linux/gpio/consumer.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
+#include <linux/of_graph.h>
 #include <linux/of.h>
 #include <linux/platform_device.h>
 #include <linux/pm_runtime.h>
 #include <linux/regmap.h>
 #include <linux/regulator/consumer.h>
 #include <linux/slab.h>
+#include <linux/usb/typec_mux.h>
+#include <linux/usb/typec_altmode.h>
 #include <sound/jack.h>
 #include <sound/pcm_params.h>
 #include <sound/pcm.h>
@@ -82,6 +85,13 @@ struct wcd937x_priv {
 	struct regmap *regmap;
 	/* micb setup lock */
 	struct mutex micb_lock;
+	/* typec handling */
+	bool typec_analog_mux;
+#if IS_ENABLED(CONFIG_TYPEC)
+	enum typec_orientation typec_orientation;
+	unsigned long typec_mode;
+	struct typec_switch *typec_switch;
+#endif /* CONFIG_TYPEC */
 	/* mbhc module */
 	struct wcd_mbhc *wcd_mbhc;
 	struct wcd_mbhc_config mbhc_cfg;
@@ -1869,7 +1879,7 @@ static void wcd937x_mbhc_moisture_config(struct snd_soc_component *component)
 {
 	struct wcd937x_priv *wcd937x = snd_soc_component_get_drvdata(component);
 
-	if (wcd937x->mbhc_cfg.moist_rref == R_OFF) {
+	if (wcd937x->mbhc_cfg.moist_rref == R_OFF || wcd937x->typec_analog_mux) {
 		snd_soc_component_write_field(component, WCD937X_MBHC_NEW_CTL_2,
 					      WCD937X_M_RTH_CTL_MASK, R_OFF);
 		return;
@@ -1905,7 +1915,7 @@ static bool wcd937x_mbhc_get_moisture_status(struct snd_soc_component *component
 	struct wcd937x_priv *wcd937x = snd_soc_component_get_drvdata(component);
 	bool ret = false;
 
-	if (wcd937x->mbhc_cfg.moist_rref == R_OFF) {
+	if (wcd937x->mbhc_cfg.moist_rref == R_OFF || wcd937x->typec_analog_mux) {
 		snd_soc_component_write_field(component, WCD937X_MBHC_NEW_CTL_2,
 					      WCD937X_M_RTH_CTL_MASK, R_OFF);
 		goto done;
@@ -2634,6 +2644,40 @@ static const struct snd_soc_component_driver soc_codec_dev_wcd937x = {
 	.endianness = 1,
 };
 
+#if IS_ENABLED(CONFIG_TYPEC)
+/* Get USB-C plug orientation to provide swap event for MBHC */
+static int wcd937x_typec_switch_set(struct typec_switch_dev *sw,
+				    enum typec_orientation orientation)
+{
+	struct wcd937x_priv *wcd937x = typec_switch_get_drvdata(sw);
+
+	wcd937x->typec_orientation = orientation;
+
+	return 0;
+}
+
+static int wcd937x_typec_mux_set(struct typec_mux_dev *mux,
+				 struct typec_mux_state *state)
+{
+	struct wcd937x_priv *wcd937x = typec_mux_get_drvdata(mux);
+	unsigned int previous_mode = wcd937x->typec_mode;
+
+	if (!wcd937x->wcd_mbhc)
+		return -EINVAL;
+
+	if (wcd937x->typec_mode != state->mode) {
+		wcd937x->typec_mode = state->mode;
+
+		if (wcd937x->typec_mode == TYPEC_MODE_AUDIO)
+			return wcd_mbhc_typec_report_plug(wcd937x->wcd_mbhc);
+		else if (previous_mode == TYPEC_MODE_AUDIO)
+			return wcd_mbhc_typec_report_unplug(wcd937x->wcd_mbhc);
+	}
+
+	return 0;
+}
+#endif /* CONFIG_TYPEC */
+
 static bool wcd937x_swap_gnd_mic(struct snd_soc_component *component)
 {
 	int value;
@@ -2644,6 +2688,13 @@ static bool wcd937x_swap_gnd_mic(struct snd_soc_component *component)
 	value = gpiod_get_value(wcd937x->us_euro_gpio);
 	gpiod_set_value(wcd937x->us_euro_gpio, !value);
 
+#if IS_ENABLED(CONFIG_TYPEC)
+	if (wcd937x->typec_analog_mux && wcd937x->typec_switch)
+		typec_switch_set(wcd937x->typec_switch,
+				 wcd937x->typec_orientation == TYPEC_ORIENTATION_REVERSE ?
+					TYPEC_ORIENTATION_NORMAL : TYPEC_ORIENTATION_REVERSE);
+#endif /* CONFIG_TYPEC */
+
 	return true;
 }
 
@@ -2761,10 +2812,24 @@ static int wcd937x_bind(struct device *dev)
 	/* Give the SDW subdevices some more time to settle */
 	usleep_range(5000, 5010);
 
+#if IS_ENABLED(CONFIG_TYPEC)
+	/*
+	 * Get the USB Type-C switch to send GND/MIC swap events.
+	 * typec_switch is fetched now to avoid a probe deadlock since
+	 * the switch depends on the typec_mux register in wcd937x_probe()
+	 */
+	if (wcd937x->typec_analog_mux) {
+		wcd937x->typec_switch = fwnode_typec_switch_get(dev->fwnode);
+		if (IS_ERR(wcd937x->typec_switch))
+			return dev_err_probe(dev, PTR_ERR(wcd937x->typec_switch),
+					     "failed to acquire orientation-switch\n");
+	}
+#endif /* CONFIG_TYPEC */
+
 	ret = component_bind_all(dev, wcd937x);
 	if (ret) {
 		dev_err(dev, "Slave bind failed, ret = %d\n", ret);
-		return ret;
+		goto err_put_typec_switch;
 	}
 
 	wcd937x->rxdev = of_sdw_find_device_by_node(wcd937x->rxnode);
@@ -2852,6 +2917,12 @@ static int wcd937x_bind(struct device *dev)
 	put_device(wcd937x->rxdev);
 err_component_unbind:
 	component_unbind_all(dev, wcd937x);
+err_put_typec_switch:
+#if IS_ENABLED(CONFIG_TYPEC)
+	if (wcd937x->typec_analog_mux)
+		typec_switch_put(wcd937x->typec_switch);
+#endif /* CONFIG_TYPEC */
+
 	return ret;
 }
 
@@ -2874,6 +2945,61 @@ static const struct component_master_ops wcd937x_comp_ops = {
 	.unbind = wcd937x_unbind,
 };
 
+#if IS_ENABLED(CONFIG_TYPEC)
+static void wcd937x_typec_mux_unregister(void *data)
+{
+	struct typec_mux_dev *typec_mux = data;
+
+	typec_mux_unregister(typec_mux);
+}
+
+static void wcd937x_typec_switch_unregister(void *data)
+{
+	struct typec_switch_dev *typec_sw = data;
+
+	typec_switch_unregister(typec_sw);
+}
+
+static int wcd937x_add_typec(struct wcd937x_priv *wcd937x, struct device *dev)
+{
+	int ret;
+	struct typec_mux_dev *typec_mux;
+	struct typec_switch_dev *typec_sw;
+	struct typec_mux_desc mux_desc = {
+		.drvdata = wcd937x,
+		.fwnode = dev_fwnode(dev),
+		.set = wcd937x_typec_mux_set,
+	};
+	struct typec_switch_desc sw_desc = {
+		.drvdata = wcd937x,
+		.fwnode = dev_fwnode(dev),
+		.set = wcd937x_typec_switch_set,
+	};
+
+	typec_mux = typec_mux_register(dev, &mux_desc);
+	if (IS_ERR(typec_mux))
+		return dev_err_probe(dev, PTR_ERR(typec_mux),
+				     "failed to register typec mux\n");
+
+	ret = devm_add_action_or_reset(dev, wcd937x_typec_mux_unregister,
+				       typec_mux);
+	if (ret)
+		return ret;
+
+	typec_sw = typec_switch_register(dev, &sw_desc);
+	if (IS_ERR(typec_sw))
+		return dev_err_probe(dev, PTR_ERR(typec_sw),
+				     "failed to register typec switch\n");
+
+	ret = devm_add_action_or_reset(dev, wcd937x_typec_switch_unregister,
+				       typec_sw);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+#endif
+
 static int wcd937x_add_slave_components(struct wcd937x_priv *wcd937x,
 					struct device *dev,
 					struct component_match **matchptr)
@@ -2907,6 +3033,9 @@ static int wcd937x_probe(struct platform_device *pdev)
 	struct device *dev = &pdev->dev;
 	struct wcd937x_priv *wcd937x;
 	struct wcd_mbhc_config *cfg;
+#if IS_ENABLED(CONFIG_TYPEC)
+	struct device_node *np;
+#endif /* CONFIG_TYPEC */
 	int ret;
 
 	wcd937x = devm_kzalloc(dev, sizeof(*wcd937x), GFP_KERNEL);
@@ -2951,6 +3080,22 @@ static int wcd937x_probe(struct platform_device *pdev)
 
 	wcd_dt_parse_mbhc_data(dev, &wcd937x->mbhc_cfg);
 
+#if IS_ENABLED(CONFIG_TYPEC)
+	/*
+	 * If the node has a port and a valid remote endpoint,
+	 * consider HP lines as connected to a USB-C SBU mux
+	 */
+	np = of_graph_get_remote_node(dev->of_node, 0, 0);
+	if (np) {
+		wcd937x->typec_analog_mux = true;
+		cfg->typec_analog_mux = true;
+
+		ret = wcd937x_add_typec(wcd937x, dev);
+		if (ret)
+			return ret;
+	}
+#endif /* CONFIG_TYPEC */
+
 	ret = wcd937x_add_slave_components(wcd937x, dev, &match);
 	if (ret)
 		return ret;
-- 
2.55.0