From: Nicolas Frattaroli <nicolas.frattaroli@collabora.com>
To: Vinod Koul <vkoul@kernel.org>,
	 Kishon Vijay Abraham I <kishon@kernel.org>,
	Rob Herring <robh@kernel.org>,
	 Krzysztof Kozlowski <krzk+dt@kernel.org>,
	 Conor Dooley <conor+dt@kernel.org>,
	Heiko Stuebner <heiko@sntech.de>,
	 Kever Yang <kever.yang@rock-chips.com>,
	 Frank Wang <frank.wang@rock-chips.com>,
	 Neil Armstrong <neil.armstrong@linaro.org>
Cc: devicetree@vger.kernel.org,
	Sebastian Reichel <sebastian.reichel@collabora.com>,
	linux-kernel@vger.kernel.org, linux-rockchip@lists.infradead.org,
	Alexey Charkov <alchark@gmail.com>,
	linux-phy@lists.infradead.org, kernel@collabora.com,
	linux-arm-kernel@lists.infradead.org
Subject: [PATCH v5 1/2] phy: rockchip: inno-usb2: add soft vbusvalid control
Date: Thu, 19 Jun 2025 20:36:36 +0200	[thread overview]
Message-ID: <20250619-rk3576-sige5-usb-v5-1-9069a7e750e1@collabora.com> (raw)
In-Reply-To: <20250619-rk3576-sige5-usb-v5-0-9069a7e750e1@collabora.com>

With USB type C connectors, the vbus detect pin of the OTG controller
attached to it is pulled high by a USB Type C controller chip such as
the fusb302. This means USB enumeration on Type-C ports never works, as
the vbus is always seen as high.

Rockchip added some GRF register flags to deal with this situation. The
RK3576 TRM calls these "soft_vbusvalid_bvalid" (con0 bit index 15) and
"soft_vbusvalid_bvalid_sel" (con0 bit index 14).

Downstream introduces a new vendor property which tells the USB 2 PHY
that it's connected to a type C port, but we can do better. Since in
such an arrangement, we'll have an OF graph connection from the USB
controller to the USB connector anyway, we can walk said OF graph and
check the connector's compatible to determine this without adding any
further vendor properties.

Do keep in mind that the usbdp PHY driver seemingly fiddles with these
register fields as well, but what it does doesn't appear to be enough
for us to get working USB enumeration, presumably because the whole
vbus_attach logic needs to be adjusted as well either way.

Signed-off-by: Nicolas Frattaroli <nicolas.frattaroli@collabora.com>
---
 drivers/phy/rockchip/phy-rockchip-inno-usb2.c | 108 +++++++++++++++++++++++++-
 1 file changed, 104 insertions(+), 4 deletions(-)

--- a/drivers/phy/rockchip/phy-rockchip-inno-usb2.c
+++ b/drivers/phy/rockchip/phy-rockchip-inno-usb2.c
@@ -17,6 +17,7 @@
 #include <linux/module.h>
 #include <linux/mutex.h>
 #include <linux/of.h>
+#include <linux/of_graph.h>
 #include <linux/of_irq.h>
 #include <linux/phy/phy.h>
 #include <linux/platform_device.h>
@@ -114,6 +115,8 @@ struct rockchip_chg_det_reg {
 /**
  * struct rockchip_usb2phy_port_cfg - usb-phy port configuration.
  * @phy_sus: phy suspend register.
+ * @svbus_en: soft vbus bvalid enable register.
+ * @svbus_sel: soft vbus bvalid selection register.
  * @bvalid_det_en: vbus valid rise detection enable register.
  * @bvalid_det_st: vbus valid rise detection status register.
  * @bvalid_det_clr: vbus valid rise detection clear register.
@@ -140,6 +143,8 @@ struct rockchip_chg_det_reg {
  */
 struct rockchip_usb2phy_port_cfg {
 	struct usb2phy_reg	phy_sus;
+	struct usb2phy_reg	svbus_en;
+	struct usb2phy_reg	svbus_sel;
 	struct usb2phy_reg	bvalid_det_en;
 	struct usb2phy_reg	bvalid_det_st;
 	struct usb2phy_reg	bvalid_det_clr;
@@ -203,6 +208,7 @@ struct rockchip_usb2phy_cfg {
  * @event_nb: hold event notification callback.
  * @state: define OTG enumeration states before device reset.
  * @mode: the dr_mode of the controller.
+ * @typec_vbus_det: whether to apply Type C logic to OTG vbus detection.
  */
 struct rockchip_usb2phy_port {
 	struct phy	*phy;
@@ -222,6 +228,7 @@ struct rockchip_usb2phy_port {
 	struct notifier_block	event_nb;
 	enum usb_otg_state	state;
 	enum usb_dr_mode	mode;
+	bool typec_vbus_det;
 };
 
 /**
@@ -495,6 +502,13 @@ static int rockchip_usb2phy_init(struct
 	mutex_lock(&rport->mutex);
 
 	if (rport->port_id == USB2PHY_PORT_OTG) {
+		if (rport->typec_vbus_det) {
+			if (rport->port_cfg->svbus_en.enable &&
+					rport->port_cfg->svbus_sel.enable) {
+				property_enable(rphy->grf, &rport->port_cfg->svbus_en, true);
+				property_enable(rphy->grf, &rport->port_cfg->svbus_sel, true);
+			}
+		}
 		if (rport->mode != USB_DR_MODE_HOST &&
 		    rport->mode != USB_DR_MODE_UNKNOWN) {
 			/* clear bvalid status and enable bvalid detect irq */
@@ -535,8 +549,7 @@ static int rockchip_usb2phy_init(struct
 			if (ret)
 				goto out;
 
-			schedule_delayed_work(&rport->otg_sm_work,
-					      OTG_SCHEDULE_DELAY * 3);
+			schedule_delayed_work(&rport->otg_sm_work, 0);
 		} else {
 			/* If OTG works in host only mode, do nothing. */
 			dev_dbg(&rport->phy->dev, "mode %d\n", rport->mode);
@@ -666,8 +679,12 @@ static void rockchip_usb2phy_otg_sm_work
 	unsigned long delay;
 	bool vbus_attach, sch_work, notify_charger;
 
-	vbus_attach = property_enabled(rphy->grf,
-				       &rport->port_cfg->utmi_bvalid);
+	if (rport->port_cfg->svbus_en.enable && rport->typec_vbus_det) {
+		vbus_attach = true;
+	} else {
+		vbus_attach = property_enabled(rphy->grf,
+					       &rport->port_cfg->utmi_bvalid);
+	}
 
 	sch_work = false;
 	notify_charger = false;
@@ -1280,6 +1297,83 @@ static int rockchip_otg_event(struct not
 	return NOTIFY_DONE;
 }
 
+static const char *const rockchip_usb2phy_typec_cons[] = {
+	"usb-c-connector",
+	NULL,
+};
+
+static struct device_node *rockchip_usb2phy_to_controller(struct rockchip_usb2phy *rphy)
+{
+	struct device_node *np;
+	struct device_node *parent;
+
+	for_each_node_with_property(np, "phys") {
+		struct of_phandle_iterator it;
+		int ret;
+
+		of_for_each_phandle(&it, ret, np, "phys", NULL, 0) {
+			parent = of_get_parent(it.node);
+			if (it.node != rphy->dev->of_node && rphy->dev->of_node != parent) {
+				if (parent)
+					of_node_put(parent);
+				continue;
+			}
+
+			/*
+			 * Either the PHY phandle we're iterating or its parent
+			 * matched, we don't care about which out of the two in
+			 * particular as we just need to know it's the right
+			 * USB controller for this PHY.
+			 */
+			of_node_put(it.node);
+			of_node_put(parent);
+			return np;
+		}
+	}
+
+	return NULL;
+}
+
+static bool rockchip_usb2phy_otg_is_type_c(struct rockchip_usb2phy *rphy)
+{
+	struct device_node *controller = rockchip_usb2phy_to_controller(rphy);
+	struct device_node *ports;
+	struct device_node *ep = NULL;
+	struct device_node *parent;
+
+	if (!controller)
+		return false;
+
+	ports = of_get_child_by_name(controller, "ports");
+	if (ports) {
+		of_node_put(controller);
+		controller = ports;
+	}
+
+	for_each_of_graph_port(controller, port) {
+		ep = of_get_child_by_name(port, "endpoint");
+		if (!ep)
+			continue;
+
+		parent = of_graph_get_remote_port_parent(ep);
+		of_node_put(ep);
+		if (!parent)
+			continue;
+
+		if (of_device_compatible_match(parent, rockchip_usb2phy_typec_cons)) {
+			of_node_put(parent);
+			of_node_put(controller);
+			return true;
+		}
+
+		of_node_put(parent);
+	}
+
+	of_node_put(controller);
+
+	return false;
+}
+
 static int rockchip_usb2phy_otg_port_init(struct rockchip_usb2phy *rphy,
 					  struct rockchip_usb2phy_port *rport,
 					  struct device_node *child_np)
@@ -1301,6 +1395,8 @@ static int rockchip_usb2phy_otg_port_ini
 
 	mutex_init(&rport->mutex);
 
+	rport->typec_vbus_det = rockchip_usb2phy_otg_is_type_c(rphy);
+
 	rport->mode = of_usb_get_dr_mode_by_phy(child_np, -1);
 	if (rport->mode == USB_DR_MODE_HOST ||
 	    rport->mode == USB_DR_MODE_UNKNOWN) {
@@ -1982,6 +2078,8 @@ static const struct rockchip_usb2phy_cfg
 		.port_cfgs	= {
 			[USB2PHY_PORT_OTG] = {
 				.phy_sus	= { 0x0000, 8, 0, 0, 0x1d1 },
+				.svbus_en	= { 0x0000, 15, 15, 0, 1 },
+				.svbus_sel	= { 0x0000, 14, 14, 0, 1 },
 				.bvalid_det_en	= { 0x00c0, 1, 1, 0, 1 },
 				.bvalid_det_st	= { 0x00c4, 1, 1, 0, 1 },
 				.bvalid_det_clr = { 0x00c8, 1, 1, 0, 1 },
@@ -2019,6 +2117,8 @@ static const struct rockchip_usb2phy_cfg
 		.port_cfgs	= {
 			[USB2PHY_PORT_OTG] = {
 				.phy_sus	= { 0x2000, 8, 0, 0, 0x1d1 },
+				.svbus_en	= { 0x2000, 15, 15, 0, 1 },
+				.svbus_sel	= { 0x2000, 14, 14, 0, 1 },
 				.bvalid_det_en	= { 0x20c0, 1, 1, 0, 1 },
 				.bvalid_det_st	= { 0x20c4, 1, 1, 0, 1 },
 				.bvalid_det_clr = { 0x20c8, 1, 1, 0, 1 },
