[PATCH 2/2] usb: typec: fsa4480: Report switch & mux events to codec

[Val Packett <val@packett.cool>]

From: Luca Weiss <luca.weiss@fairphone.com>

In the Type-C graph, the FSA4480 switch is in between the USB-C connector
and the audio codec, but the audio codec also needs to receive the
switch and mux events from the FSA4480.

Update the driver to get an Type-C mux on the next endpoint and
broadcast the recevied mux & switch state to it.

Signed-off-by: Luca Weiss <luca.weiss@fairphone.com>
[val: enable the SENSE/MIC bits used downstream, they do improve detection]
Signed-off-by: Val Packett <val@packett.cool>
---

Originaly in the WIP tree Luca sent me, the chunk with the two enable bits
was in a separate debug commit. I have tested the difference, without them
the codec does detect the headphones but complains in the process:

wcd937x_codec audio-codec: Impedance detect ramp error, c1=0, x1=0x0
wcd937x_codec audio-codec: Impedance detect ramp error, c1=0, x1=0x0
wcd937x_codec audio-codec: Impedance detect ramp error, c1=0, x1=0x0
wcd937x_codec audio-codec: wcd937x_mbhc_get_result_params: d1=30, c1=3, x1=0xb69, z_val=19776 (milliohm)

With FSA4480_ENABLE_SENSE | FSA4480_ENABLE_MIC set, there are no complaints,
the headset is detected on the first iteration:

wcd937x_codec audio-codec: wcd937x_mbhc_get_result_params: d1=5, c1=3, x1=0x2d31, z_val=33984 (milliohm)
wcd937x_codec audio-codec: wcd937x_mbhc_get_result_params: d1=5, c1=3, x1=0x2dc7, z_val=33380 (milliohm)
wcd937x_codec audio-codec: wcd937x_mbhc_get_result_params: d1=5, c1=3, x1=0x2d57, z_val=33829 (milliohm)

---
 drivers/usb/typec/mux/fsa4480.c | 54 ++++++++++++++++++++++++++++-----
 1 file changed, 47 insertions(+), 7 deletions(-)

diff --git a/drivers/usb/typec/mux/fsa4480.c b/drivers/usb/typec/mux/fsa4480.c
index bea0c1deec94..d992a7e1887c 100644
--- a/drivers/usb/typec/mux/fsa4480.c
+++ b/drivers/usb/typec/mux/fsa4480.c
@@ -60,6 +60,9 @@ struct fsa4480 {
 
 	struct regmap *regmap;
 
+	struct typec_mux *codec;
+	struct typec_switch *codec_switch;
+
 	enum typec_orientation orientation;
 	unsigned long mode;
 	unsigned int svid;
@@ -115,7 +118,8 @@ static int fsa4480_set(struct fsa4480 *fsa)
 		}
 	} else if (fsa->mode == TYPEC_MODE_AUDIO) {
 		/* Audio Accessory Mode, setup to auto Jack Detection */
-		enable |= FSA4480_ENABLE_USB | FSA4480_ENABLE_AGND;
+		enable |= FSA4480_ENABLE_USB | FSA4480_ENABLE_AGND |
+			 FSA4480_ENABLE_SENSE | FSA4480_ENABLE_MIC;
 	} else
 		return -EOPNOTSUPP;
 
@@ -162,7 +166,11 @@ static int fsa4480_switch_set(struct typec_switch_dev *sw,
 
 	mutex_unlock(&fsa->lock);
 
-	return ret;
+	if (ret)
+		return ret;
+
+	/* Report orientation to codec after switch has been done */
+	return typec_switch_set(fsa->codec_switch, orientation);
 }
 
 static int fsa4480_mux_set(struct typec_mux_dev *mux, struct typec_mux_state *state)
@@ -185,7 +193,11 @@ static int fsa4480_mux_set(struct typec_mux_dev *mux, struct typec_mux_state *st
 
 	mutex_unlock(&fsa->lock);
 
-	return ret;
+	if (ret)
+		return ret;
+
+	/* Report event to codec after switch has been done */
+	return typec_mux_set(fsa->codec, state);
 }
 
 enum {
@@ -287,6 +299,19 @@ static int fsa4480_probe(struct i2c_client *client)
 		FIELD_GET(FSA4480_DEVICE_ID_REV_ID, val),
 		FIELD_GET(FSA4480_DEVICE_ID_VENDOR_ID, val));
 
+	/* Get Codec's MUX & Switch devices */
+	fsa->codec = fwnode_typec_mux_get(dev->fwnode);
+	if (IS_ERR(fsa->codec))
+		return dev_err_probe(dev, PTR_ERR(fsa->codec),
+				     "failed to acquire codec mode-switch\n");
+
+	fsa->codec_switch = fwnode_typec_switch_get(dev->fwnode);
+	if (IS_ERR(fsa->codec_switch)) {
+		ret = dev_err_probe(dev, PTR_ERR(fsa->codec_switch),
+				    "failed to acquire codec orientation-switch\n");
+		goto err_put_mux;
+	}
+
 	/* Safe mode */
 	fsa->cur_enable = FSA4480_ENABLE_DEVICE | FSA4480_ENABLE_USB;
 	fsa->mode = TYPEC_STATE_SAFE;
@@ -310,8 +335,11 @@ static int fsa4480_probe(struct i2c_client *client)
 	sw_desc.set = fsa4480_switch_set;
 
 	fsa->sw = typec_switch_register(dev, &sw_desc);
-	if (IS_ERR(fsa->sw))
-		return dev_err_probe(dev, PTR_ERR(fsa->sw), "failed to register typec switch\n");
+	if (IS_ERR(fsa->sw)) {
+		ret = dev_err_probe(dev, PTR_ERR(fsa->sw),
+				    "failed to register typec switch\n");
+		goto err_put_switch;
+	}
 
 	mux_desc.drvdata = fsa;
 	mux_desc.fwnode = dev_fwnode(dev);
@@ -319,12 +347,24 @@ static int fsa4480_probe(struct i2c_client *client)
 
 	fsa->mux = typec_mux_register(dev, &mux_desc);
 	if (IS_ERR(fsa->mux)) {
-		typec_switch_unregister(fsa->sw);
-		return dev_err_probe(dev, PTR_ERR(fsa->mux), "failed to register typec mux\n");
+		ret = dev_err_probe(dev, PTR_ERR(fsa->mux),
+				    "failed to register typec mux\n");
+		goto err_unregister_switch;
 	}
 
 	i2c_set_clientdata(client, fsa);
 	return 0;
+
+err_unregister_switch:
+	typec_switch_unregister(fsa->sw);
+
+err_put_switch:
+	typec_switch_put(fsa->codec_switch);
+
+err_put_mux:
+	typec_mux_put(fsa->codec);
+
+	return ret;
 }
 
 static void fsa4480_remove(struct i2c_client *client)
-- 
2.55.0