// SPDX-License-Identifier: GPL-2.0
/*
 * USB-ACPI glue code
 *
 * Copyright 2012 Red Hat <mjg@redhat.com>
 */
#include <linux/module.h>
#include <linux/usb.h>
#include <linux/device.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/acpi.h>
#include <linux/pci.h>
#include <linux/usb/hcd.h>

#include "hub.h"

/**
 * usb_acpi_power_manageable - check whether usb port has
 * acpi power resource.
 * @hdev: USB device belonging to the usb hub
 * @index: port index based zero
 *
 * Return true if the port has acpi power resource and false if no.
 */
bool usb_acpi_power_manageable(struct usb_device *hdev, int index)
{
        acpi_handle port_handle;
        int port1 = index + 1;

        port_handle = usb_get_hub_port_acpi_handle(hdev,
                port1);
        if (port_handle)
                return acpi_bus_power_manageable(port_handle);
        else
                return false;
}
EXPORT_SYMBOL_GPL(usb_acpi_power_manageable);

#define UUID_USB_CONTROLLER_DSM "ce2ee385-00e6-48cb-9f05-2edb927c4899"
#define USB_DSM_DISABLE_U1_U2_FOR_PORT  5

/**
 * usb_acpi_port_lpm_incapable - check if lpm should be disabled for a port.
 * @hdev: USB device belonging to the usb hub
 * @index: zero based port index
 *
 * Some USB3 ports may not support USB3 link power management U1/U2 states
 * due to different retimer setup. ACPI provides _DSM method which returns 0x01
 * if U1 and U2 states should be disabled. Evaluate _DSM with:
 * Arg0: UUID = ce2ee385-00e6-48cb-9f05-2edb927c4899
 * Arg1: Revision ID = 0
 * Arg2: Function Index = 5
 * Arg3: (empty)
 *
 * Return 1 if USB3 port is LPM incapable, negative on error, otherwise 0
 */

int usb_acpi_port_lpm_incapable(struct usb_device *hdev, int index)
{
        union acpi_object *obj;
        acpi_handle port_handle;
        int port1 = index + 1;
        guid_t guid;
        int ret;

        ret = guid_parse(UUID_USB_CONTROLLER_DSM, &guid);
        if (ret)
                return ret;

        port_handle = usb_get_hub_port_acpi_handle(hdev, port1);
        if (!port_handle) {
                dev_dbg(&hdev->dev, "port-%d no acpi handle\n", port1);
                return -ENODEV;
        }

        if (!acpi_check_dsm(port_handle, &guid, 0,
                            BIT(USB_DSM_DISABLE_U1_U2_FOR_PORT))) {
                dev_dbg(&hdev->dev, "port-%d no _DSM function %d\n",
                        port1, USB_DSM_DISABLE_U1_U2_FOR_PORT);
                return -ENODEV;
        }

        obj = acpi_evaluate_dsm_typed(port_handle, &guid, 0,
                                      USB_DSM_DISABLE_U1_U2_FOR_PORT, NULL,
                                      ACPI_TYPE_INTEGER);
        if (!obj) {
                dev_dbg(&hdev->dev, "evaluate port-%d _DSM failed\n", port1);
                return -EINVAL;
        }

        if (obj->integer.value == 0x01)
                ret = 1;

        ACPI_FREE(obj);

        return ret;
}
EXPORT_SYMBOL_GPL(usb_acpi_port_lpm_incapable);

/**
 * usb_acpi_set_power_state - control usb port's power via acpi power
 * resource
 * @hdev: USB device belonging to the usb hub
 * @index: port index based zero
 * @enable: power state expected to be set
 *
 * Notice to use usb_acpi_power_manageable() to check whether the usb port
 * has acpi power resource before invoking this function.
 *
 * Returns 0 on success, else negative errno.
 */
int usb_acpi_set_power_state(struct usb_device *hdev, int index, bool enable)
{
        struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
        struct usb_port *port_dev;
        acpi_handle port_handle;
        unsigned char state;
        int port1 = index + 1;
        int error = -EINVAL;

        if (!hub)
                return -ENODEV;
        port_dev = hub->ports[port1 - 1];

        port_handle = (acpi_handle) usb_get_hub_port_acpi_handle(hdev, port1);
        if (!port_handle)
                return error;

        if (enable)
                state = ACPI_STATE_D0;
        else
                state = ACPI_STATE_D3_COLD;

        error = acpi_bus_set_power(port_handle, state);
        if (!error)
                dev_dbg(&port_dev->dev, "acpi: power was set to %d\n", enable);
        else
                dev_dbg(&port_dev->dev, "acpi: power failed to be set\n");

        return error;
}
EXPORT_SYMBOL_GPL(usb_acpi_set_power_state);

/**
 * usb_acpi_add_usb4_devlink - add device link to USB4 Host Interface for tunneled USB3 devices
 *
 * @udev: Tunneled USB3 device connected to a roothub.
 *
 * Adds a device link between a tunneled USB3 device and the USB4 Host Interface
 * device to ensure correct runtime PM suspend and resume order. This function
 * should only be called for tunneled USB3 devices.
 * The USB4 Host Interface this tunneled device depends on is found from the roothub
 * port ACPI device specific data _DSD entry.
 *
 * Return: negative error code on failure, 0 otherwise
 */
static int usb_acpi_add_usb4_devlink(struct usb_device *udev)
{
        struct device_link *link;
        struct usb_port *port_dev;
        struct usb_hub *hub;

        if (!udev->parent || udev->parent->parent)
                return 0;

        hub = usb_hub_to_struct_hub(udev->parent);
        if (!hub)
                return 0;
        port_dev = hub->ports[udev->portnum - 1];

        struct fwnode_handle *nhi_fwnode __free(fwnode_handle) =
                fwnode_find_reference(dev_fwnode(&port_dev->dev), "usb4-host-interface", 0);

        if (IS_ERR(nhi_fwnode) || !nhi_fwnode->dev)
                return 0;

        link = device_link_add(&port_dev->child->dev, nhi_fwnode->dev,
                               DL_FLAG_STATELESS |
                               DL_FLAG_RPM_ACTIVE |
                               DL_FLAG_PM_RUNTIME);
        if (!link) {
                dev_err(&port_dev->dev, "Failed to created device link from %s to %s\n",
                        dev_name(&port_dev->child->dev), dev_name(nhi_fwnode->dev));
                return -EINVAL;
        }

        dev_dbg(&port_dev->dev, "Created device link from %s to %s\n",
                dev_name(&port_dev->child->dev), dev_name(nhi_fwnode->dev));

        udev->usb4_link = link;

        return 0;
}

/*
 * Private to usb-acpi, all the core needs to know is that
 * port_dev->location is non-zero when it has been set by the firmware.
 */
#define USB_ACPI_LOCATION_VALID (1 << 31)

static void
usb_acpi_get_connect_type(struct usb_port *port_dev, acpi_handle *handle)
{
        enum usb_port_connect_type connect_type = USB_PORT_CONNECT_TYPE_UNKNOWN;
        struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
        union acpi_object *upc = NULL;
        struct acpi_pld_info *pld = NULL;
        acpi_status status;

        /*
         * According to 9.14 in ACPI Spec 6.2. _PLD indicates whether usb port
         * is user visible and _UPC indicates whether it is connectable. If
         * the port was visible and connectable, it could be freely connected
         * and disconnected with USB devices. If no visible and connectable,
         * a usb device is directly hard-wired to the port. If no visible and
         * no connectable, the port would be not used.
         */

        if (acpi_get_physical_device_location(handle, &pld) && pld)
                port_dev->location = USB_ACPI_LOCATION_VALID |
                        pld->group_token << 8 | pld->group_position;

        status = acpi_evaluate_object(handle, "_UPC", NULL, &buffer);
        if (ACPI_FAILURE(status))
                goto out;

        upc = buffer.pointer;
        if (!upc || (upc->type != ACPI_TYPE_PACKAGE) || upc->package.count != 4)
                goto out;

        /* UPC states port is connectable */
        if (upc->package.elements[0].integer.value)
                if (!pld)
                        ; /* keep connect_type as unknown */
                else if (pld->user_visible)
                        connect_type = USB_PORT_CONNECT_TYPE_HOT_PLUG;
                else
                        connect_type = USB_PORT_CONNECT_TYPE_HARD_WIRED;
        else
                connect_type = USB_PORT_NOT_USED;
out:
        port_dev->connect_type = connect_type;
        kfree(upc);
        ACPI_FREE(pld);
}

static struct acpi_device *
usb_acpi_get_companion_for_port(struct usb_port *port_dev)
{
        struct usb_device *udev;
        struct acpi_device *adev;
        acpi_handle *parent_handle;
        int port1;

        /* Get the struct usb_device point of port's hub */
        udev = to_usb_device(port_dev->dev.parent->parent);

        /*
         * The root hub ports' parent is the root hub. The non-root-hub
         * ports' parent is the parent hub port which the hub is
         * connected to.
         */
        if (!udev->parent) {
                adev = ACPI_COMPANION(&udev->dev);
                port1 = usb_hcd_find_raw_port_number(bus_to_hcd(udev->bus),
                                                     port_dev->portnum);
        } else {
                parent_handle = usb_get_hub_port_acpi_handle(udev->parent,
                                                             udev->portnum);
                if (!parent_handle)
                        return NULL;

                adev = acpi_fetch_acpi_dev(parent_handle);
                port1 = port_dev->portnum;
        }

        return acpi_find_child_by_adr(adev, port1);
}

static struct acpi_device *
usb_acpi_find_companion_for_port(struct usb_port *port_dev)
{
        struct acpi_device *adev;

        adev = usb_acpi_get_companion_for_port(port_dev);
        if (!adev)
                return NULL;

        usb_acpi_get_connect_type(port_dev, adev->handle);

        return adev;
}

static struct acpi_device *
usb_acpi_find_companion_for_device(struct usb_device *udev)
{
        struct acpi_device *adev;
        struct usb_port *port_dev;
        struct usb_hub *hub;

        if (!udev->parent) {
                /*
                 * root hub is only child (_ADR=0) under its parent, the HC.
                 * sysdev pointer is the HC as seen from firmware.
                 */
                adev = ACPI_COMPANION(udev->bus->sysdev);
                return acpi_find_child_device(adev, 0, false);
        }

        hub = usb_hub_to_struct_hub(udev->parent);
        if (!hub)
                return NULL;


        /* Tunneled USB3 devices depend on USB4 Host Interface, set device link to it */
        if (udev->speed >= USB_SPEED_SUPER &&
            udev->tunnel_mode != USB_LINK_NATIVE)
                usb_acpi_add_usb4_devlink(udev);

        /*
         * This is an embedded USB device connected to a port and such
         * devices share port's ACPI companion.
         */
        port_dev = hub->ports[udev->portnum - 1];
        return usb_acpi_get_companion_for_port(port_dev);
}

static struct acpi_device *usb_acpi_find_companion(struct device *dev)
{
        /*
         * The USB hierarchy like following:
         *
         * Device (EHC1)
         *      Device (HUBN)
         *              Device (PR01)
         *                      Device (PR11)
         *                      Device (PR12)
         *                              Device (FN12)
         *                              Device (FN13)
         *                      Device (PR13)
         *                      ...
         * where HUBN is root hub, and PRNN are USB ports and devices
         * connected to them, and FNNN are individualk functions for
         * connected composite USB devices. PRNN and FNNN may contain
         * _CRS and other methods describing sideband resources for
         * the connected device.
         *
         * On the kernel side both root hub and embedded USB devices are
         * represented as instances of usb_device structure, and ports
         * are represented as usb_port structures, so the whole process
         * is split into 2 parts: finding companions for devices and
         * finding companions for ports.
         *
         * Note that we do not handle individual functions of composite
         * devices yet, for that we would need to assign companions to
         * devices corresponding to USB interfaces.
         */
        if (is_usb_device(dev))
                return usb_acpi_find_companion_for_device(to_usb_device(dev));
        else if (is_usb_port(dev))
                return usb_acpi_find_companion_for_port(to_usb_port(dev));

        return NULL;
}

static bool usb_acpi_bus_match(struct device *dev)
{
        return is_usb_device(dev) || is_usb_port(dev);
}

static struct acpi_bus_type usb_acpi_bus = {
        .name = "USB",
        .match = usb_acpi_bus_match,
        .find_companion = usb_acpi_find_companion,
};

int usb_acpi_register(void)
{
        return register_acpi_bus_type(&usb_acpi_bus);
}

void usb_acpi_unregister(void)
{
        unregister_acpi_bus_type(&usb_acpi_bus);
}