Adding upstream version 6.1.76.upstream/6.1.76upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 143 insertions, 0 deletions

diff --git a/drivers/usb/misc/onboard_usb_hub_pdevs.c b/drivers/usb/misc/onboard_usb_hub_pdevs.c
new file mode 100644
index 000000000..ed22a18f4
--- /dev/null
+++ b/drivers/usb/misc/onboard_usb_hub_pdevs.c
@@ -0,0 +1,143 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * API for creating and destroying USB onboard hub platform devices
+ *
+ * Copyright (c) 2022, Google LLC
+ */
+
+#include <linux/device.h>
+#include <linux/export.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/usb.h>
+#include <linux/usb/hcd.h>
+#include <linux/usb/of.h>
+#include <linux/usb/onboard_hub.h>
+
+#include "onboard_usb_hub.h"
+
+struct pdev_list_entry {
+	struct platform_device *pdev;
+	struct list_head node;
+};
+
+static bool of_is_onboard_usb_hub(const struct device_node *np)
+{
+	return !!of_match_node(onboard_hub_match, np);
+}
+
+/**
+ * onboard_hub_create_pdevs -- create platform devices for onboard USB hubs
+ * @parent_hub	: parent hub to scan for connected onboard hubs
+ * @pdev_list	: list of onboard hub platform devices owned by the parent hub
+ *
+ * Creates a platform device for each supported onboard hub that is connected to
+ * the given parent hub. The platform device is in charge of initializing the
+ * hub (enable regulators, take the hub out of reset, ...) and can optionally
+ * control whether the hub remains powered during system suspend or not.
+ *
+ * To keep track of the platform devices they are added to a list that is owned
+ * by the parent hub.
+ *
+ * Some background about the logic in this function, which can be a bit hard
+ * to follow:
+ *
+ * Root hubs don't have dedicated device tree nodes, but use the node of their
+ * HCD. The primary and secondary HCD are usually represented by a single DT
+ * node. That means the root hubs of the primary and secondary HCD share the
+ * same device tree node (the HCD node). As a result this function can be called
+ * twice with the same DT node for root hubs. We only want to create a single
+ * platform device for each physical onboard hub, hence for root hubs the loop
+ * is only executed for the root hub of the primary HCD. Since the function
+ * scans through all child nodes it still creates pdevs for onboard hubs
+ * connected to the root hub of the secondary HCD if needed.
+ *
+ * Further there must be only one platform device for onboard hubs with a peer
+ * hub (the hub is a single physical device). To achieve this two measures are
+ * taken: pdevs for onboard hubs with a peer are only created when the function
+ * is called on behalf of the parent hub that is connected to the primary HCD
+ * (directly or through other hubs). For onboard hubs connected to root hubs
+ * the function processes the nodes of both peers. A platform device is only
+ * created if the peer hub doesn't have one already.
+ */
+void onboard_hub_create_pdevs(struct usb_device *parent_hub, struct list_head *pdev_list)
+{
+	int i;
+	struct usb_hcd *hcd = bus_to_hcd(parent_hub->bus);
+	struct device_node *np, *npc;
+	struct platform_device *pdev;
+	struct pdev_list_entry *pdle;
+
+	if (!parent_hub->dev.of_node)
+		return;
+
+	if (!parent_hub->parent && !usb_hcd_is_primary_hcd(hcd))
+		return;
+
+	for (i = 1; i <= parent_hub->maxchild; i++) {
+		np = usb_of_get_device_node(parent_hub, i);
+		if (!np)
+			continue;
+
+		if (!of_is_onboard_usb_hub(np))
+			goto node_put;
+
+		npc = of_parse_phandle(np, "peer-hub", 0);
+		if (npc) {
+			if (!usb_hcd_is_primary_hcd(hcd)) {
+				of_node_put(npc);
+				goto node_put;
+			}
+
+			pdev = of_find_device_by_node(npc);
+			of_node_put(npc);
+
+			if (pdev) {
+				put_device(&pdev->dev);
+				goto node_put;
+			}
+		}
+
+		pdev = of_platform_device_create(np, NULL, &parent_hub->dev);
+		if (!pdev) {
+			dev_err(&parent_hub->dev,
+				"failed to create platform device for onboard hub '%pOF'\n", np);
+			goto node_put;
+		}
+
+		pdle = kzalloc(sizeof(*pdle), GFP_KERNEL);
+		if (!pdle) {
+			of_platform_device_destroy(&pdev->dev, NULL);
+			goto node_put;
+		}
+
+		pdle->pdev = pdev;
+		list_add(&pdle->node, pdev_list);
+
+node_put:
+		of_node_put(np);
+	}
+}
+EXPORT_SYMBOL_GPL(onboard_hub_create_pdevs);
+
+/**
+ * onboard_hub_destroy_pdevs -- free resources of onboard hub platform devices
+ * @pdev_list	: list of onboard hub platform devices
+ *
+ * Destroys the platform devices in the given list and frees the memory associated
+ * with the list entry.
+ */
+void onboard_hub_destroy_pdevs(struct list_head *pdev_list)
+{
+	struct pdev_list_entry *pdle, *tmp;
+
+	list_for_each_entry_safe(pdle, tmp, pdev_list, node) {
+		list_del(&pdle->node);
+		of_platform_device_destroy(&pdle->pdev->dev, NULL);
+		kfree(pdle);
+	}
+}
+EXPORT_SYMBOL_GPL(onboard_hub_destroy_pdevs);