phy: qcom: qmp-combo: register a typec mux to change the QMPPHY_MODE

Register a typec mux in order to change the PHY mode on the Type-C
mux events depending on the mode and the svid when in Altmode setup.

The DisplayPort phy should be left enabled if is still powered on
by the DRM DisplayPort controller, so bail out until the DisplayPort
PHY is not powered off.

The Type-C Mode/SVID only changes on plug/unplug, and USB SAFE states
will be set in between of USB-Only, Combo and DisplayPort Only so
this will leave enough time to the DRM DisplayPort controller to
turn of the DisplayPort PHY.

Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
[konrad: renaming, rewording, bug fixes]
Signed-off-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Tested-by: Neil Armstrong <neil.armstrong@linaro.org> # on Lenovo Thinkpad T14S
Link: https://lore.kernel.org/r/20250807-topic-4ln_dp_respin-v4-5-43272d6eca92@oss.qualcomm.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

Author: superna9999

drivers/phy/qualcomm/phy-qcom-qmp-combo.c

@@ -19,6 +19,7 @@
 #include <linux/reset.h>
 #include <linux/slab.h>
 #include <linux/usb/typec.h>
+#include <linux/usb/typec_dp.h>
 #include <linux/usb/typec_mux.h>
 
 #include <drm/bridge/aux-bridge.h>
@@ -1868,6 +1869,8 @@ struct qmp_combo {
 
 	struct typec_switch_dev *sw;
 	enum typec_orientation orientation;
+
+	struct typec_mux_dev *mux;
 };
 
 static void qmp_v3_dp_aux_init(struct qmp_combo *qmp);
@@ -3802,17 +3805,109 @@ static int qmp_combo_typec_switch_set(struct typec_switch_dev *sw,
 	return 0;
 }
 
-static void qmp_combo_typec_unregister(void *data)
+static int qmp_combo_typec_mux_set(struct typec_mux_dev *mux, struct typec_mux_state *state)
+{
+	struct qmp_combo *qmp = typec_mux_get_drvdata(mux);
+	const struct qmp_phy_cfg *cfg = qmp->cfg;
+	enum qmpphy_mode new_mode;
+	unsigned int svid;
+
+	guard(mutex)(&qmp->phy_mutex);
+
+	if (state->alt)
+		svid = state->alt->svid;
+	else
+		svid = 0;
+
+	if (svid == USB_TYPEC_DP_SID) {
+		switch (state->mode) {
+		/* DP Only */
+		case TYPEC_DP_STATE_C:
+		case TYPEC_DP_STATE_E:
+			new_mode = QMPPHY_MODE_DP_ONLY;
+			break;
+
+		/* DP + USB */
+		case TYPEC_DP_STATE_D:
+		case TYPEC_DP_STATE_F:
+
+		/* Safe fallback...*/
+		default:
+			new_mode = QMPPHY_MODE_USB3DP;
+			break;
+		}
+	} else {
+		/* No DP SVID => don't care, assume it's just USB3 */
+		new_mode = QMPPHY_MODE_USB3_ONLY;
+	}
+
+	if (new_mode == qmp->qmpphy_mode) {
+		dev_dbg(qmp->dev, "typec_mux_set: same qmpphy mode, bail out\n");
+		return 0;
+	}
+
+	if (qmp->qmpphy_mode != QMPPHY_MODE_USB3_ONLY && qmp->dp_powered_on) {
+		dev_dbg(qmp->dev, "typec_mux_set: DP PHY is still in use, delaying switch\n");
+		return 0;
+	}
+
+	dev_dbg(qmp->dev, "typec_mux_set: switching from qmpphy mode %d to %d\n",
+		qmp->qmpphy_mode, new_mode);
+
+	qmp->qmpphy_mode = new_mode;
+
+	if (qmp->init_count) {
+		if (qmp->usb_init_count)
+			qmp_combo_usb_power_off(qmp->usb_phy);
+
+		if (qmp->dp_init_count)
+			writel(DP_PHY_PD_CTL_PSR_PWRDN, qmp->dp_dp_phy + QSERDES_DP_PHY_PD_CTL);
+
+		qmp_combo_com_exit(qmp, true);
+
+		/* Now everything's powered down, power up the right PHYs */
+		qmp_combo_com_init(qmp, true);
+
+		if (new_mode == QMPPHY_MODE_DP_ONLY) {
+			if (qmp->usb_init_count)
+				qmp->usb_init_count--;
+		}
+
+		if (new_mode == QMPPHY_MODE_USB3DP || new_mode == QMPPHY_MODE_USB3_ONLY) {
+			qmp_combo_usb_power_on(qmp->usb_phy);
+			if (!qmp->usb_init_count)
+				qmp->usb_init_count++;
+		}
+
+		if (new_mode == QMPPHY_MODE_DP_ONLY || new_mode == QMPPHY_MODE_USB3DP) {
+			if (qmp->dp_init_count)
+				cfg->dp_aux_init(qmp);
+		}
+	}
+
+	return 0;
+}
+
+static void qmp_combo_typec_switch_unregister(void *data)
 {
 	struct qmp_combo *qmp = data;
 
 	typec_switch_unregister(qmp->sw);
 }
 
-static int qmp_combo_typec_switch_register(struct qmp_combo *qmp)
+static void qmp_combo_typec_mux_unregister(void *data)
+{
+	struct qmp_combo *qmp = data;
+
+	typec_mux_unregister(qmp->mux);
+}
+
+static int qmp_combo_typec_register(struct qmp_combo *qmp)
 {
 	struct typec_switch_desc sw_desc = {};
+	struct typec_mux_desc mux_desc = { };
 	struct device *dev = qmp->dev;
+	int ret;
 
 	sw_desc.drvdata = qmp;
 	sw_desc.fwnode = dev->fwnode;
@@ -3823,10 +3918,23 @@ static int qmp_combo_typec_switch_register(struct qmp_combo *qmp)
 		return PTR_ERR(qmp->sw);
 	}
 
-	return devm_add_action_or_reset(dev, qmp_combo_typec_unregister, qmp);
+	ret = devm_add_action_or_reset(dev, qmp_combo_typec_switch_unregister, qmp);
+	if (ret)
+		return ret;
+
+	mux_desc.drvdata = qmp;
+	mux_desc.fwnode = dev->fwnode;
+	mux_desc.set = qmp_combo_typec_mux_set;
+	qmp->mux = typec_mux_register(dev, &mux_desc);
+	if (IS_ERR(qmp->mux)) {
+		dev_err(dev, "Unable to register typec mux: %pe\n", qmp->mux);
+		return PTR_ERR(qmp->mux);
+	}
+
+	return devm_add_action_or_reset(dev, qmp_combo_typec_mux_unregister, qmp);
 }
 #else
-static int qmp_combo_typec_switch_register(struct qmp_combo *qmp)
+static int qmp_combo_typec_register(struct qmp_combo *qmp)
 {
 	return 0;
 }
@@ -4059,7 +4167,7 @@ static int qmp_combo_probe(struct platform_device *pdev)
 	if (ret)
 		goto err_node_put;
 
-	ret = qmp_combo_typec_switch_register(qmp);
+	ret = qmp_combo_typec_register(qmp);
 	if (ret)
 		goto err_node_put;