[PATCH 04/22] usb: core: Set connect_type of ports based on DT node

[Stephen Boyd]

When a USB hub is described in DT, such as any device that matches the
onboard-hub driver, the connect_type is set to "unknown" or
USB_PORT_CONNECT_TYPE_UNKNOWN. This makes any device plugged into that
USB port report their 'removable' device attribute as "unknown". Improve
the connect_type attribute for ports, and in turn the removable
attribute for USB devices, by looking for child devices with a reg
property or an OF graph when the device is described in DT.

If the graph exists, endpoints that are connected to a remote node must
be something like a usb-{a,b,c}-connector compatible node, or an
intermediate node like a redriver, and not a hardwired USB device on the
board. Set the connect_type to USB_PORT_CONNECT_TYPE_HOT_PLUG in this
case because the device is going to be plugged in. Set the connect_type
to USB_PORT_CONNECT_TYPE_HARD_WIRED if there's a child node for the port
like 'device at 2' for port2. Set the connect_type to USB_PORT_NOT_USED if
there isn't an endpoint or child node corresponding to the port number.

To make sure things don't change, only set the port to not used if
there are child nodes. This way an onboard hub connect_type doesn't
change until ports are added or child nodes are added to describe
hardwired devices. It's assumed that all ports or no ports will be
described for a device.

Cc: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
Cc: Matthias Kaehlcke <mka at chromium.org>
Cc: <linux-usb at vger.kernel.org>
Cc: <devicetree at vger.kernel.org>
Cc: Pin-yen Lin <treapking at chromium.org>
Cc: maciek swiech <drmasquatch at google.com>
Signed-off-by: Stephen Boyd <swboyd at chromium.org>
---
 drivers/usb/core/port.c | 37 +++++++++++++++++++++++++++++++++++++
 1 file changed, 37 insertions(+)

diff --git a/drivers/usb/core/port.c b/drivers/usb/core/port.c
index c628c1abc907..622b8ada157c 100644
--- a/drivers/usb/core/port.c
+++ b/drivers/usb/core/port.c
@@ -9,6 +9,8 @@
 
 #include <linux/kstrtox.h>
 #include <linux/slab.h>
+#include <linux/of.h>
+#include <linux/of_graph.h>
 #include <linux/pm_qos.h>
 #include <linux/component.h>
 
@@ -696,7 +698,10 @@ int usb_hub_create_port_device(struct usb_hub *hub, int port1)
 {
 	struct usb_port *port_dev;
 	struct usb_device *hdev = hub->hdev;
+	struct device_node *np, *child, *ep, *remote_np, *port_np;
 	int retval;
+	enum usb_port_connect_type connect_type = USB_PORT_CONNECT_TYPE_UNKNOWN;
+	u32 reg;
 
 	port_dev = kzalloc(sizeof(*port_dev), GFP_KERNEL);
 	if (!port_dev)
@@ -708,6 +713,38 @@ int usb_hub_create_port_device(struct usb_hub *hub, int port1)
 		return -ENOMEM;
 	}
 
+	np = hdev->dev.of_node;
+	/* Only set connect_type if binding has ports/hardwired devices. */
+	if (of_get_child_count(np))
+		connect_type = USB_PORT_NOT_USED;
+
+	/* Hotplug ports are connected and available in the OF graph. */
+	if (of_graph_is_present(np)) {
+		port_np = of_graph_get_port_by_id(np, port1);
+		if (port_np) {
+			ep = of_graph_get_endpoint_by_regs(np, port1, -1);
+			if (ep) {
+				remote_np = of_graph_get_remote_port_parent(ep);
+				of_node_put(ep);
+				if (of_device_is_available(remote_np))
+					connect_type = USB_PORT_CONNECT_TYPE_HOT_PLUG;
+				of_node_put(remote_np);
+			}
+		}
+		of_node_put(port_np);
+	}
+
+	/*
+	 * Hard-wired ports are child nodes with a reg property corresponding
+	 * to the port number.
+	 */
+	for_each_available_child_of_node(np, child) {
+		if (!of_property_read_u32(child, "reg", &reg) && reg == port1)
+			connect_type = USB_PORT_CONNECT_TYPE_HARD_WIRED;
+	}
+
+	port_dev->connect_type = connect_type;
+
 	hub->ports[port1 - 1] = port_dev;
 	port_dev->portnum = port1;
 	set_bit(port1, hub->power_bits);
-- 
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