treewide: remove redundant IS_ERR() before error code check

[linux/fpc-iii.git] / drivers / usb / typec / class.c

// SPDX-License-Identifier: GPL-2.0
/*
 * USB Type-C Connector Class
 *
 * Copyright (C) 2017, Intel Corporation
 * Author: Heikki Krogerus <heikki.krogerus@linux.intel.com>
 */

#include <linux/device.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/property.h>
#include <linux/slab.h>

#include "bus.h"

struct typec_plug {
        struct device                   dev;
        enum typec_plug_index           index;
        struct ida                      mode_ids;
};

struct typec_cable {
        struct device                   dev;
        enum typec_plug_type            type;
        struct usb_pd_identity          *identity;
        unsigned int                    active:1;
};

struct typec_partner {
        struct device                   dev;
        unsigned int                    usb_pd:1;
        struct usb_pd_identity          *identity;
        enum typec_accessory            accessory;
        struct ida                      mode_ids;
};

struct typec_port {
        unsigned int                    id;
        struct device                   dev;
        struct ida                      mode_ids;

        int                             prefer_role;
        enum typec_data_role            data_role;
        enum typec_role                 pwr_role;
        enum typec_role                 vconn_role;
        enum typec_pwr_opmode           pwr_opmode;
        enum typec_port_type            port_type;
        struct mutex                    port_type_lock;

        enum typec_orientation          orientation;
        struct typec_switch             *sw;
        struct typec_mux                *mux;

        const struct typec_capability   *cap;
        const struct typec_operations   *ops;
};

#define to_typec_port(_dev_) container_of(_dev_, struct typec_port, dev)
#define to_typec_plug(_dev_) container_of(_dev_, struct typec_plug, dev)
#define to_typec_cable(_dev_) container_of(_dev_, struct typec_cable, dev)
#define to_typec_partner(_dev_) container_of(_dev_, struct typec_partner, dev)

static const struct device_type typec_partner_dev_type;
static const struct device_type typec_cable_dev_type;
static const struct device_type typec_plug_dev_type;

#define is_typec_partner(_dev_) (_dev_->type == &typec_partner_dev_type)
#define is_typec_cable(_dev_) (_dev_->type == &typec_cable_dev_type)
#define is_typec_plug(_dev_) (_dev_->type == &typec_plug_dev_type)

static DEFINE_IDA(typec_index_ida);
static struct class *typec_class;

/* ------------------------------------------------------------------------- */
/* Common attributes */

static const char * const typec_accessory_modes[] = {
        [TYPEC_ACCESSORY_NONE]          = "none",
        [TYPEC_ACCESSORY_AUDIO]         = "analog_audio",
        [TYPEC_ACCESSORY_DEBUG]         = "debug",
};

static struct usb_pd_identity *get_pd_identity(struct device *dev)
{
        if (is_typec_partner(dev)) {
                struct typec_partner *partner = to_typec_partner(dev);

                return partner->identity;
        } else if (is_typec_cable(dev)) {
                struct typec_cable *cable = to_typec_cable(dev);

                return cable->identity;
        }
        return NULL;
}

static ssize_t id_header_show(struct device *dev, struct device_attribute *attr,
                              char *buf)
{
        struct usb_pd_identity *id = get_pd_identity(dev);

        return sprintf(buf, "0x%08x\n", id->id_header);
}
static DEVICE_ATTR_RO(id_header);

static ssize_t cert_stat_show(struct device *dev, struct device_attribute *attr,
                              char *buf)
{
        struct usb_pd_identity *id = get_pd_identity(dev);

        return sprintf(buf, "0x%08x\n", id->cert_stat);
}
static DEVICE_ATTR_RO(cert_stat);

static ssize_t product_show(struct device *dev, struct device_attribute *attr,
                            char *buf)
{
        struct usb_pd_identity *id = get_pd_identity(dev);

        return sprintf(buf, "0x%08x\n", id->product);
}
static DEVICE_ATTR_RO(product);

static struct attribute *usb_pd_id_attrs[] = {
        &dev_attr_id_header.attr,
        &dev_attr_cert_stat.attr,
        &dev_attr_product.attr,
        NULL
};

static const struct attribute_group usb_pd_id_group = {
        .name = "identity",
        .attrs = usb_pd_id_attrs,
};

static const struct attribute_group *usb_pd_id_groups[] = {
        &usb_pd_id_group,
        NULL,
};

static void typec_report_identity(struct device *dev)
{
        sysfs_notify(&dev->kobj, "identity", "id_header");
        sysfs_notify(&dev->kobj, "identity", "cert_stat");
        sysfs_notify(&dev->kobj, "identity", "product");
}

/* ------------------------------------------------------------------------- */
/* Alternate Modes */

static int altmode_match(struct device *dev, void *data)
{
        struct typec_altmode *adev = to_typec_altmode(dev);
        struct typec_device_id *id = data;

        if (!is_typec_altmode(dev))
                return 0;

        return ((adev->svid == id->svid) && (adev->mode == id->mode));
}

static void typec_altmode_set_partner(struct altmode *altmode)
{
        struct typec_altmode *adev = &altmode->adev;
        struct typec_device_id id = { adev->svid, adev->mode, };
        struct typec_port *port = typec_altmode2port(adev);
        struct altmode *partner;
        struct device *dev;

        dev = device_find_child(&port->dev, &id, altmode_match);
        if (!dev)
                return;

        /* Bind the port alt mode to the partner/plug alt mode. */
        partner = to_altmode(to_typec_altmode(dev));
        altmode->partner = partner;

        /* Bind the partner/plug alt mode to the port alt mode. */
        if (is_typec_plug(adev->dev.parent)) {
                struct typec_plug *plug = to_typec_plug(adev->dev.parent);

                partner->plug[plug->index] = altmode;
        } else {
                partner->partner = altmode;
        }
}

static void typec_altmode_put_partner(struct altmode *altmode)
{
        struct altmode *partner = altmode->partner;
        struct typec_altmode *adev;

        if (!partner)
                return;

        adev = &partner->adev;

        if (is_typec_plug(adev->dev.parent)) {
                struct typec_plug *plug = to_typec_plug(adev->dev.parent);

                partner->plug[plug->index] = NULL;
        } else {
                partner->partner = NULL;
        }
        put_device(&adev->dev);
}

static void *typec_port_match(struct device_connection *con, int ep, void *data)
{
        struct device *dev;

        /*
         * FIXME: Check does the fwnode supports the requested SVID. If it does
         * we need to return ERR_PTR(-PROBE_DEFER) when there is no device.
         */
        if (con->fwnode)
                return class_find_device_by_fwnode(typec_class, con->fwnode);

        dev = class_find_device_by_name(typec_class, con->endpoint[ep]);

        return dev ? dev : ERR_PTR(-EPROBE_DEFER);
}

struct typec_altmode *
typec_altmode_register_notifier(struct device *dev, u16 svid, u8 mode,
                                struct notifier_block *nb)
{
        struct typec_device_id id = { svid, mode, };
        struct device *altmode_dev;
        struct device *port_dev;
        struct altmode *altmode;
        int ret;

        /* Find the port linked to the caller */
        port_dev = device_connection_find_match(dev, NULL, NULL,
                                                typec_port_match);
        if (IS_ERR_OR_NULL(port_dev))
                return port_dev ? ERR_CAST(port_dev) : ERR_PTR(-ENODEV);

        /* Find the altmode with matching svid */
        altmode_dev = device_find_child(port_dev, &id, altmode_match);

        put_device(port_dev);

        if (!altmode_dev)
                return ERR_PTR(-ENODEV);

        altmode = to_altmode(to_typec_altmode(altmode_dev));

        /* Register notifier */
        ret = blocking_notifier_chain_register(&altmode->nh, nb);
        if (ret) {
                put_device(altmode_dev);
                return ERR_PTR(ret);
        }

        return &altmode->adev;
}
EXPORT_SYMBOL_GPL(typec_altmode_register_notifier);

void typec_altmode_unregister_notifier(struct typec_altmode *adev,
                                       struct notifier_block *nb)
{
        struct altmode *altmode = to_altmode(adev);

        blocking_notifier_chain_unregister(&altmode->nh, nb);
        put_device(&adev->dev);
}
EXPORT_SYMBOL_GPL(typec_altmode_unregister_notifier);

/**
 * typec_altmode_update_active - Report Enter/Exit mode
 * @adev: Handle to the alternate mode
 * @active: True when the mode has been entered
 *
 * If a partner or cable plug executes Enter/Exit Mode command successfully, the
 * drivers use this routine to report the updated state of the mode.
 */
void typec_altmode_update_active(struct typec_altmode *adev, bool active)
{
        char dir[6];

        if (adev->active == active)
                return;

        if (!is_typec_port(adev->dev.parent) && adev->dev.driver) {
                if (!active)
                        module_put(adev->dev.driver->owner);
                else
                        WARN_ON(!try_module_get(adev->dev.driver->owner));
        }

        adev->active = active;
        snprintf(dir, sizeof(dir), "mode%d", adev->mode);
        sysfs_notify(&adev->dev.kobj, dir, "active");
        sysfs_notify(&adev->dev.kobj, NULL, "active");
        kobject_uevent(&adev->dev.kobj, KOBJ_CHANGE);
}
EXPORT_SYMBOL_GPL(typec_altmode_update_active);

/**
 * typec_altmode2port - Alternate Mode to USB Type-C port
 * @alt: The Alternate Mode
 *
 * Returns handle to the port that a cable plug or partner with @alt is
 * connected to.
 */
struct typec_port *typec_altmode2port(struct typec_altmode *alt)
{
        if (is_typec_plug(alt->dev.parent))
                return to_typec_port(alt->dev.parent->parent->parent);
        if (is_typec_partner(alt->dev.parent))
                return to_typec_port(alt->dev.parent->parent);
        if (is_typec_port(alt->dev.parent))
                return to_typec_port(alt->dev.parent);

        return NULL;
}
EXPORT_SYMBOL_GPL(typec_altmode2port);

static ssize_t
vdo_show(struct device *dev, struct device_attribute *attr, char *buf)
{
        struct typec_altmode *alt = to_typec_altmode(dev);

        return sprintf(buf, "0x%08x\n", alt->vdo);
}
static DEVICE_ATTR_RO(vdo);

static ssize_t
description_show(struct device *dev, struct device_attribute *attr, char *buf)
{
        struct typec_altmode *alt = to_typec_altmode(dev);

        return sprintf(buf, "%s\n", alt->desc ? alt->desc : "");
}
static DEVICE_ATTR_RO(description);

static ssize_t
active_show(struct device *dev, struct device_attribute *attr, char *buf)
{
        struct typec_altmode *alt = to_typec_altmode(dev);

        return sprintf(buf, "%s\n", alt->active ? "yes" : "no");
}

static ssize_t active_store(struct device *dev, struct device_attribute *attr,
                            const char *buf, size_t size)
{
        struct typec_altmode *adev = to_typec_altmode(dev);
        struct altmode *altmode = to_altmode(adev);
        bool enter;
        int ret;

        ret = kstrtobool(buf, &enter);
        if (ret)
                return ret;

        if (adev->active == enter)
                return size;

        if (is_typec_port(adev->dev.parent)) {
                typec_altmode_update_active(adev, enter);

                /* Make sure that the partner exits the mode before disabling */
                if (altmode->partner && !enter && altmode->partner->adev.active)
                        typec_altmode_exit(&altmode->partner->adev);
        } else if (altmode->partner) {
                if (enter && !altmode->partner->adev.active) {
                        dev_warn(dev, "port has the mode disabled\n");
                        return -EPERM;
                }
        }

        /* Note: If there is no driver, the mode will not be entered */
        if (adev->ops && adev->ops->activate) {
                ret = adev->ops->activate(adev, enter);
                if (ret)
                        return ret;
        }

        return size;
}
static DEVICE_ATTR_RW(active);

static ssize_t
supported_roles_show(struct device *dev, struct device_attribute *attr,
                     char *buf)
{
        struct altmode *alt = to_altmode(to_typec_altmode(dev));
        ssize_t ret;

        switch (alt->roles) {
        case TYPEC_PORT_SRC:
                ret = sprintf(buf, "source\n");
                break;
        case TYPEC_PORT_SNK:
                ret = sprintf(buf, "sink\n");
                break;
        case TYPEC_PORT_DRP:
        default:
                ret = sprintf(buf, "source sink\n");
                break;
        }
        return ret;
}
static DEVICE_ATTR_RO(supported_roles);

static ssize_t
mode_show(struct device *dev, struct device_attribute *attr, char *buf)
{
        struct typec_altmode *adev = to_typec_altmode(dev);

        return sprintf(buf, "%u\n", adev->mode);
}
static DEVICE_ATTR_RO(mode);

static ssize_t
svid_show(struct device *dev, struct device_attribute *attr, char *buf)
{
        struct typec_altmode *adev = to_typec_altmode(dev);

        return sprintf(buf, "%04x\n", adev->svid);
}
static DEVICE_ATTR_RO(svid);

static struct attribute *typec_altmode_attrs[] = {
        &dev_attr_active.attr,
        &dev_attr_mode.attr,
        &dev_attr_svid.attr,
        &dev_attr_vdo.attr,
        NULL
};
ATTRIBUTE_GROUPS(typec_altmode);

static int altmode_id_get(struct device *dev)
{
        struct ida *ids;

        if (is_typec_partner(dev))
                ids = &to_typec_partner(dev)->mode_ids;
        else if (is_typec_plug(dev))
                ids = &to_typec_plug(dev)->mode_ids;
        else
                ids = &to_typec_port(dev)->mode_ids;

        return ida_simple_get(ids, 0, 0, GFP_KERNEL);
}

static void altmode_id_remove(struct device *dev, int id)
{
        struct ida *ids;

        if (is_typec_partner(dev))
                ids = &to_typec_partner(dev)->mode_ids;
        else if (is_typec_plug(dev))
                ids = &to_typec_plug(dev)->mode_ids;
        else
                ids = &to_typec_port(dev)->mode_ids;

        ida_simple_remove(ids, id);
}

static void typec_altmode_release(struct device *dev)
{
        struct altmode *alt = to_altmode(to_typec_altmode(dev));

        typec_altmode_put_partner(alt);

        altmode_id_remove(alt->adev.dev.parent, alt->id);
        kfree(alt);
}

const struct device_type typec_altmode_dev_type = {
        .name = "typec_alternate_mode",
        .groups = typec_altmode_groups,
        .release = typec_altmode_release,
};

static struct typec_altmode *
typec_register_altmode(struct device *parent,
                       const struct typec_altmode_desc *desc)
{
        unsigned int id = altmode_id_get(parent);
        bool is_port = is_typec_port(parent);
        struct altmode *alt;
        int ret;

        alt = kzalloc(sizeof(*alt), GFP_KERNEL);
        if (!alt)
                return ERR_PTR(-ENOMEM);

        alt->adev.svid = desc->svid;
        alt->adev.mode = desc->mode;
        alt->adev.vdo = desc->vdo;
        alt->roles = desc->roles;
        alt->id = id;

        alt->attrs[0] = &dev_attr_vdo.attr;
        alt->attrs[1] = &dev_attr_description.attr;
        alt->attrs[2] = &dev_attr_active.attr;

        if (is_port) {
                alt->attrs[3] = &dev_attr_supported_roles.attr;
                alt->adev.active = true; /* Enabled by default */
        }

        sprintf(alt->group_name, "mode%d", desc->mode);
        alt->group.name = alt->group_name;
        alt->group.attrs = alt->attrs;
        alt->groups[0] = &alt->group;

        alt->adev.dev.parent = parent;
        alt->adev.dev.groups = alt->groups;
        alt->adev.dev.type = &typec_altmode_dev_type;
        dev_set_name(&alt->adev.dev, "%s.%u", dev_name(parent), id);

        /* Link partners and plugs with the ports */
        if (is_port)
                BLOCKING_INIT_NOTIFIER_HEAD(&alt->nh);
        else
                typec_altmode_set_partner(alt);

        /* The partners are bind to drivers */
        if (is_typec_partner(parent))
                alt->adev.dev.bus = &typec_bus;

        ret = device_register(&alt->adev.dev);
        if (ret) {
                dev_err(parent, "failed to register alternate mode (%d)\n",
                        ret);
                put_device(&alt->adev.dev);
                return ERR_PTR(ret);
        }

        return &alt->adev;
}

/**
 * typec_unregister_altmode - Unregister Alternate Mode
 * @adev: The alternate mode to be unregistered
 *
 * Unregister device created with typec_partner_register_altmode(),
 * typec_plug_register_altmode() or typec_port_register_altmode().
 */
void typec_unregister_altmode(struct typec_altmode *adev)
{
        if (IS_ERR_OR_NULL(adev))
                return;
        typec_mux_put(to_altmode(adev)->mux);
        device_unregister(&adev->dev);
}
EXPORT_SYMBOL_GPL(typec_unregister_altmode);

/* ------------------------------------------------------------------------- */
/* Type-C Partners */

static ssize_t accessory_mode_show(struct device *dev,
                                   struct device_attribute *attr,
                                   char *buf)
{
        struct typec_partner *p = to_typec_partner(dev);

        return sprintf(buf, "%s\n", typec_accessory_modes[p->accessory]);
}
static DEVICE_ATTR_RO(accessory_mode);

static ssize_t supports_usb_power_delivery_show(struct device *dev,
                                                struct device_attribute *attr,
                                                char *buf)
{
        struct typec_partner *p = to_typec_partner(dev);

        return sprintf(buf, "%s\n", p->usb_pd ? "yes" : "no");
}
static DEVICE_ATTR_RO(supports_usb_power_delivery);

static struct attribute *typec_partner_attrs[] = {
        &dev_attr_accessory_mode.attr,
        &dev_attr_supports_usb_power_delivery.attr,
        NULL
};
ATTRIBUTE_GROUPS(typec_partner);

static void typec_partner_release(struct device *dev)
{
        struct typec_partner *partner = to_typec_partner(dev);

        ida_destroy(&partner->mode_ids);
        kfree(partner);
}

static const struct device_type typec_partner_dev_type = {
        .name = "typec_partner",
        .groups = typec_partner_groups,
        .release = typec_partner_release,
};

/**
 * typec_partner_set_identity - Report result from Discover Identity command
 * @partner: The partner updated identity values
 *
 * This routine is used to report that the result of Discover Identity USB power
 * delivery command has become available.
 */
int typec_partner_set_identity(struct typec_partner *partner)
{
        if (!partner->identity)
                return -EINVAL;

        typec_report_identity(&partner->dev);
        return 0;
}
EXPORT_SYMBOL_GPL(typec_partner_set_identity);

/**
 * typec_partner_register_altmode - Register USB Type-C Partner Alternate Mode
 * @partner: USB Type-C Partner that supports the alternate mode
 * @desc: Description of the alternate mode
 *
 * This routine is used to register each alternate mode individually that
 * @partner has listed in response to Discover SVIDs command. The modes for a
 * SVID listed in response to Discover Modes command need to be listed in an
 * array in @desc.
 *
 * Returns handle to the alternate mode on success or NULL on failure.
 */
struct typec_altmode *
typec_partner_register_altmode(struct typec_partner *partner,
                               const struct typec_altmode_desc *desc)
{
        return typec_register_altmode(&partner->dev, desc);
}
EXPORT_SYMBOL_GPL(typec_partner_register_altmode);

/**
 * typec_register_partner - Register a USB Type-C Partner
 * @port: The USB Type-C Port the partner is connected to
 * @desc: Description of the partner
 *
 * Registers a device for USB Type-C Partner described in @desc.
 *
 * Returns handle to the partner on success or ERR_PTR on failure.
 */
struct typec_partner *typec_register_partner(struct typec_port *port,
                                             struct typec_partner_desc *desc)
{
        struct typec_partner *partner;
        int ret;

        partner = kzalloc(sizeof(*partner), GFP_KERNEL);
        if (!partner)
                return ERR_PTR(-ENOMEM);

        ida_init(&partner->mode_ids);
        partner->usb_pd = desc->usb_pd;
        partner->accessory = desc->accessory;

        if (desc->identity) {
                /*
                 * Creating directory for the identity only if the driver is
                 * able to provide data to it.
                 */
                partner->dev.groups = usb_pd_id_groups;
                partner->identity = desc->identity;
        }

        partner->dev.class = typec_class;
        partner->dev.parent = &port->dev;
        partner->dev.type = &typec_partner_dev_type;
        dev_set_name(&partner->dev, "%s-partner", dev_name(&port->dev));

        ret = device_register(&partner->dev);
        if (ret) {
                dev_err(&port->dev, "failed to register partner (%d)\n", ret);
                put_device(&partner->dev);
                return ERR_PTR(ret);
        }

        return partner;
}
EXPORT_SYMBOL_GPL(typec_register_partner);

/**
 * typec_unregister_partner - Unregister a USB Type-C Partner
 * @partner: The partner to be unregistered
 *
 * Unregister device created with typec_register_partner().
 */
void typec_unregister_partner(struct typec_partner *partner)
{
        if (!IS_ERR_OR_NULL(partner))
                device_unregister(&partner->dev);
}
EXPORT_SYMBOL_GPL(typec_unregister_partner);

/* ------------------------------------------------------------------------- */
/* Type-C Cable Plugs */

static void typec_plug_release(struct device *dev)
{
        struct typec_plug *plug = to_typec_plug(dev);

        ida_destroy(&plug->mode_ids);
        kfree(plug);
}

static const struct device_type typec_plug_dev_type = {
        .name = "typec_plug",
        .release = typec_plug_release,
};

/**
 * typec_plug_register_altmode - Register USB Type-C Cable Plug Alternate Mode
 * @plug: USB Type-C Cable Plug that supports the alternate mode
 * @desc: Description of the alternate mode
 *
 * This routine is used to register each alternate mode individually that @plug
 * has listed in response to Discover SVIDs command. The modes for a SVID that
 * the plug lists in response to Discover Modes command need to be listed in an
 * array in @desc.
 *
 * Returns handle to the alternate mode on success or ERR_PTR on failure.
 */
struct typec_altmode *
typec_plug_register_altmode(struct typec_plug *plug,
                            const struct typec_altmode_desc *desc)
{
        return typec_register_altmode(&plug->dev, desc);
}
EXPORT_SYMBOL_GPL(typec_plug_register_altmode);

/**
 * typec_register_plug - Register a USB Type-C Cable Plug
 * @cable: USB Type-C Cable with the plug
 * @desc: Description of the cable plug
 *
 * Registers a device for USB Type-C Cable Plug described in @desc. A USB Type-C
 * Cable Plug represents a plug with electronics in it that can response to USB
 * Power Delivery SOP Prime or SOP Double Prime packages.
 *
 * Returns handle to the cable plug on success or ERR_PTR on failure.
 */
struct typec_plug *typec_register_plug(struct typec_cable *cable,
                                       struct typec_plug_desc *desc)
{
        struct typec_plug *plug;
        char name[8];
        int ret;

        plug = kzalloc(sizeof(*plug), GFP_KERNEL);
        if (!plug)
                return ERR_PTR(-ENOMEM);

        sprintf(name, "plug%d", desc->index);

        ida_init(&plug->mode_ids);
        plug->index = desc->index;
        plug->dev.class = typec_class;
        plug->dev.parent = &cable->dev;
        plug->dev.type = &typec_plug_dev_type;
        dev_set_name(&plug->dev, "%s-%s", dev_name(cable->dev.parent), name);

        ret = device_register(&plug->dev);
        if (ret) {
                dev_err(&cable->dev, "failed to register plug (%d)\n", ret);
                put_device(&plug->dev);
                return ERR_PTR(ret);
        }

        return plug;
}
EXPORT_SYMBOL_GPL(typec_register_plug);

/**
 * typec_unregister_plug - Unregister a USB Type-C Cable Plug
 * @plug: The cable plug to be unregistered
 *
 * Unregister device created with typec_register_plug().
 */
void typec_unregister_plug(struct typec_plug *plug)
{
        if (!IS_ERR_OR_NULL(plug))
                device_unregister(&plug->dev);
}
EXPORT_SYMBOL_GPL(typec_unregister_plug);

/* Type-C Cables */

static ssize_t
type_show(struct device *dev, struct device_attribute *attr, char *buf)
{
        struct typec_cable *cable = to_typec_cable(dev);

        return sprintf(buf, "%s\n", cable->active ? "active" : "passive");
}
static DEVICE_ATTR_RO(type);

static const char * const typec_plug_types[] = {
        [USB_PLUG_NONE]         = "unknown",
        [USB_PLUG_TYPE_A]       = "type-a",
        [USB_PLUG_TYPE_B]       = "type-b",
        [USB_PLUG_TYPE_C]       = "type-c",
        [USB_PLUG_CAPTIVE]      = "captive",
};

static ssize_t plug_type_show(struct device *dev,
                              struct device_attribute *attr, char *buf)
{
        struct typec_cable *cable = to_typec_cable(dev);

        return sprintf(buf, "%s\n", typec_plug_types[cable->type]);
}
static DEVICE_ATTR_RO(plug_type);

static struct attribute *typec_cable_attrs[] = {
        &dev_attr_type.attr,
        &dev_attr_plug_type.attr,
        NULL
};
ATTRIBUTE_GROUPS(typec_cable);

static void typec_cable_release(struct device *dev)
{
        struct typec_cable *cable = to_typec_cable(dev);

        kfree(cable);
}

static const struct device_type typec_cable_dev_type = {
        .name = "typec_cable",
        .groups = typec_cable_groups,
        .release = typec_cable_release,
};

static int cable_match(struct device *dev, void *data)
{
        return is_typec_cable(dev);
}

/**
 * typec_cable_get - Get a reference to the USB Type-C cable
 * @port: The USB Type-C Port the cable is connected to
 *
 * The caller must decrement the reference count with typec_cable_put() after
 * use.
 */
struct typec_cable *typec_cable_get(struct typec_port *port)
{
        struct device *dev;

        dev = device_find_child(&port->dev, NULL, cable_match);
        if (!dev)
                return NULL;

        return to_typec_cable(dev);
}
EXPORT_SYMBOL_GPL(typec_cable_get);

/**
 * typec_cable_get - Decrement the reference count on USB Type-C cable
 * @cable: The USB Type-C cable
 */
void typec_cable_put(struct typec_cable *cable)
{
        put_device(&cable->dev);
}
EXPORT_SYMBOL_GPL(typec_cable_put);

/**
 * typec_cable_is_active - Check is the USB Type-C cable active or passive
 * @cable: The USB Type-C Cable
 *
 * Return 1 if the cable is active or 0 if it's passive.
 */
int typec_cable_is_active(struct typec_cable *cable)
{
        return cable->active;
}
EXPORT_SYMBOL_GPL(typec_cable_is_active);

/**
 * typec_cable_set_identity - Report result from Discover Identity command
 * @cable: The cable updated identity values
 *
 * This routine is used to report that the result of Discover Identity USB power
 * delivery command has become available.
 */
int typec_cable_set_identity(struct typec_cable *cable)
{
        if (!cable->identity)
                return -EINVAL;

        typec_report_identity(&cable->dev);
        return 0;
}
EXPORT_SYMBOL_GPL(typec_cable_set_identity);

/**
 * typec_register_cable - Register a USB Type-C Cable
 * @port: The USB Type-C Port the cable is connected to
 * @desc: Description of the cable
 *
 * Registers a device for USB Type-C Cable described in @desc. The cable will be
 * parent for the optional cable plug devises.
 *
 * Returns handle to the cable on success or ERR_PTR on failure.
 */
struct typec_cable *typec_register_cable(struct typec_port *port,
                                         struct typec_cable_desc *desc)
{
        struct typec_cable *cable;
        int ret;

        cable = kzalloc(sizeof(*cable), GFP_KERNEL);
        if (!cable)
                return ERR_PTR(-ENOMEM);

        cable->type = desc->type;
        cable->active = desc->active;

        if (desc->identity) {
                /*
                 * Creating directory for the identity only if the driver is
                 * able to provide data to it.
                 */
                cable->dev.groups = usb_pd_id_groups;
                cable->identity = desc->identity;
        }

        cable->dev.class = typec_class;
        cable->dev.parent = &port->dev;
        cable->dev.type = &typec_cable_dev_type;
        dev_set_name(&cable->dev, "%s-cable", dev_name(&port->dev));

        ret = device_register(&cable->dev);
        if (ret) {
                dev_err(&port->dev, "failed to register cable (%d)\n", ret);
                put_device(&cable->dev);
                return ERR_PTR(ret);
        }

        return cable;
}
EXPORT_SYMBOL_GPL(typec_register_cable);

/**
 * typec_unregister_cable - Unregister a USB Type-C Cable
 * @cable: The cable to be unregistered
 *
 * Unregister device created with typec_register_cable().
 */
void typec_unregister_cable(struct typec_cable *cable)
{
        if (!IS_ERR_OR_NULL(cable))
                device_unregister(&cable->dev);
}
EXPORT_SYMBOL_GPL(typec_unregister_cable);

/* ------------------------------------------------------------------------- */
/* USB Type-C ports */

static const char * const typec_roles[] = {
        [TYPEC_SINK]    = "sink",
        [TYPEC_SOURCE]  = "source",
};

static const char * const typec_data_roles[] = {
        [TYPEC_DEVICE]  = "device",
        [TYPEC_HOST]    = "host",
};

static const char * const typec_port_power_roles[] = {
        [TYPEC_PORT_SRC] = "source",
        [TYPEC_PORT_SNK] = "sink",
        [TYPEC_PORT_DRP] = "dual",
};

static const char * const typec_port_data_roles[] = {
        [TYPEC_PORT_DFP] = "host",
        [TYPEC_PORT_UFP] = "device",
        [TYPEC_PORT_DRD] = "dual",
};

static const char * const typec_port_types_drp[] = {
        [TYPEC_PORT_SRC] = "dual [source] sink",
        [TYPEC_PORT_SNK] = "dual source [sink]",
        [TYPEC_PORT_DRP] = "[dual] source sink",
};

static ssize_t
preferred_role_store(struct device *dev, struct device_attribute *attr,
                     const char *buf, size_t size)
{
        struct typec_port *port = to_typec_port(dev);
        int role;
        int ret;

        if (port->cap->type != TYPEC_PORT_DRP) {
                dev_dbg(dev, "Preferred role only supported with DRP ports\n");
                return -EOPNOTSUPP;
        }

        if (!port->ops || !port->ops->try_role) {
                dev_dbg(dev, "Setting preferred role not supported\n");
                return -EOPNOTSUPP;
        }

        role = sysfs_match_string(typec_roles, buf);
        if (role < 0) {
                if (sysfs_streq(buf, "none"))
                        role = TYPEC_NO_PREFERRED_ROLE;
                else
                        return -EINVAL;
        }

        ret = port->ops->try_role(port, role);
        if (ret)
                return ret;

        port->prefer_role = role;
        return size;
}

static ssize_t
preferred_role_show(struct device *dev, struct device_attribute *attr,
                    char *buf)
{
        struct typec_port *port = to_typec_port(dev);

        if (port->cap->type != TYPEC_PORT_DRP)
                return 0;

        if (port->prefer_role < 0)
                return 0;

        return sprintf(buf, "%s\n", typec_roles[port->prefer_role]);
}
static DEVICE_ATTR_RW(preferred_role);

static ssize_t data_role_store(struct device *dev,
                               struct device_attribute *attr,
                               const char *buf, size_t size)
{
        struct typec_port *port = to_typec_port(dev);
        int ret;

        if (!port->ops || !port->ops->dr_set) {
                dev_dbg(dev, "data role swapping not supported\n");
                return -EOPNOTSUPP;
        }

        ret = sysfs_match_string(typec_data_roles, buf);
        if (ret < 0)
                return ret;

        mutex_lock(&port->port_type_lock);
        if (port->cap->data != TYPEC_PORT_DRD) {
                ret = -EOPNOTSUPP;
                goto unlock_and_ret;
        }

        ret = port->ops->dr_set(port, ret);
        if (ret)
                goto unlock_and_ret;

        ret = size;
unlock_and_ret:
        mutex_unlock(&port->port_type_lock);
        return ret;
}

static ssize_t data_role_show(struct device *dev,
                              struct device_attribute *attr, char *buf)
{
        struct typec_port *port = to_typec_port(dev);

        if (port->cap->data == TYPEC_PORT_DRD)
                return sprintf(buf, "%s\n", port->data_role == TYPEC_HOST ?
                               "[host] device" : "host [device]");

        return sprintf(buf, "[%s]\n", typec_data_roles[port->data_role]);
}
static DEVICE_ATTR_RW(data_role);

static ssize_t power_role_store(struct device *dev,
                                struct device_attribute *attr,
                                const char *buf, size_t size)
{
        struct typec_port *port = to_typec_port(dev);
        int ret;

        if (!port->cap->pd_revision) {
                dev_dbg(dev, "USB Power Delivery not supported\n");
                return -EOPNOTSUPP;
        }

        if (!port->ops || !port->ops->pr_set) {
                dev_dbg(dev, "power role swapping not supported\n");
                return -EOPNOTSUPP;
        }

        if (port->pwr_opmode != TYPEC_PWR_MODE_PD) {
                dev_dbg(dev, "partner unable to swap power role\n");
                return -EIO;
        }

        ret = sysfs_match_string(typec_roles, buf);
        if (ret < 0)
                return ret;

        mutex_lock(&port->port_type_lock);
        if (port->port_type != TYPEC_PORT_DRP) {
                dev_dbg(dev, "port type fixed at \"%s\"",
                             typec_port_power_roles[port->port_type]);
                ret = -EOPNOTSUPP;
                goto unlock_and_ret;
        }

        ret = port->ops->pr_set(port, ret);
        if (ret)
                goto unlock_and_ret;

        ret = size;
unlock_and_ret:
        mutex_unlock(&port->port_type_lock);
        return ret;
}

static ssize_t power_role_show(struct device *dev,
                               struct device_attribute *attr, char *buf)
{
        struct typec_port *port = to_typec_port(dev);

        if (port->cap->type == TYPEC_PORT_DRP)
                return sprintf(buf, "%s\n", port->pwr_role == TYPEC_SOURCE ?
                               "[source] sink" : "source [sink]");

        return sprintf(buf, "[%s]\n", typec_roles[port->pwr_role]);
}
static DEVICE_ATTR_RW(power_role);

static ssize_t
port_type_store(struct device *dev, struct device_attribute *attr,
                        const char *buf, size_t size)
{
        struct typec_port *port = to_typec_port(dev);
        int ret;
        enum typec_port_type type;

        if (port->cap->type != TYPEC_PORT_DRP ||
            !port->ops || !port->ops->port_type_set) {
                dev_dbg(dev, "changing port type not supported\n");
                return -EOPNOTSUPP;
        }

        ret = sysfs_match_string(typec_port_power_roles, buf);
        if (ret < 0)
                return ret;

        type = ret;
        mutex_lock(&port->port_type_lock);

        if (port->port_type == type) {
                ret = size;
                goto unlock_and_ret;
        }

        ret = port->ops->port_type_set(port, type);
        if (ret)
                goto unlock_and_ret;

        port->port_type = type;
        ret = size;

unlock_and_ret:
        mutex_unlock(&port->port_type_lock);
        return ret;
}

static ssize_t
port_type_show(struct device *dev, struct device_attribute *attr,
                char *buf)
{
        struct typec_port *port = to_typec_port(dev);

        if (port->cap->type == TYPEC_PORT_DRP)
                return sprintf(buf, "%s\n",
                               typec_port_types_drp[port->port_type]);

        return sprintf(buf, "[%s]\n", typec_port_power_roles[port->cap->type]);
}
static DEVICE_ATTR_RW(port_type);

static const char * const typec_pwr_opmodes[] = {
        [TYPEC_PWR_MODE_USB]    = "default",
        [TYPEC_PWR_MODE_1_5A]   = "1.5A",
        [TYPEC_PWR_MODE_3_0A]   = "3.0A",
        [TYPEC_PWR_MODE_PD]     = "usb_power_delivery",
};

static ssize_t power_operation_mode_show(struct device *dev,
                                         struct device_attribute *attr,
                                         char *buf)
{
        struct typec_port *port = to_typec_port(dev);

        return sprintf(buf, "%s\n", typec_pwr_opmodes[port->pwr_opmode]);
}
static DEVICE_ATTR_RO(power_operation_mode);

static ssize_t vconn_source_store(struct device *dev,
                                  struct device_attribute *attr,
                                  const char *buf, size_t size)
{
        struct typec_port *port = to_typec_port(dev);
        bool source;
        int ret;

        if (!port->cap->pd_revision) {
                dev_dbg(dev, "VCONN swap depends on USB Power Delivery\n");
                return -EOPNOTSUPP;
        }

        if (!port->ops || !port->ops->vconn_set) {
                dev_dbg(dev, "VCONN swapping not supported\n");
                return -EOPNOTSUPP;
        }

        ret = kstrtobool(buf, &source);
        if (ret)
                return ret;

        ret = port->ops->vconn_set(port, (enum typec_role)source);
        if (ret)
                return ret;

        return size;
}

static ssize_t vconn_source_show(struct device *dev,
                                 struct device_attribute *attr, char *buf)
{
        struct typec_port *port = to_typec_port(dev);

        return sprintf(buf, "%s\n",
                       port->vconn_role == TYPEC_SOURCE ? "yes" : "no");
}
static DEVICE_ATTR_RW(vconn_source);

static ssize_t supported_accessory_modes_show(struct device *dev,
                                              struct device_attribute *attr,
                                              char *buf)
{
        struct typec_port *port = to_typec_port(dev);
        ssize_t ret = 0;
        int i;

        for (i = 0; i < ARRAY_SIZE(port->cap->accessory); i++) {
                if (port->cap->accessory[i])
                        ret += sprintf(buf + ret, "%s ",
                               typec_accessory_modes[port->cap->accessory[i]]);
        }

        if (!ret)
                return sprintf(buf, "none\n");

        buf[ret - 1] = '\n';

        return ret;
}
static DEVICE_ATTR_RO(supported_accessory_modes);

static ssize_t usb_typec_revision_show(struct device *dev,
                                       struct device_attribute *attr,
                                       char *buf)
{
        struct typec_port *port = to_typec_port(dev);
        u16 rev = port->cap->revision;

        return sprintf(buf, "%d.%d\n", (rev >> 8) & 0xff, (rev >> 4) & 0xf);
}
static DEVICE_ATTR_RO(usb_typec_revision);

static ssize_t usb_power_delivery_revision_show(struct device *dev,
                                                struct device_attribute *attr,
                                                char *buf)
{
        struct typec_port *p = to_typec_port(dev);

        return sprintf(buf, "%d\n", (p->cap->pd_revision >> 8) & 0xff);
}
static DEVICE_ATTR_RO(usb_power_delivery_revision);

static struct attribute *typec_attrs[] = {
        &dev_attr_data_role.attr,
        &dev_attr_power_operation_mode.attr,
        &dev_attr_power_role.attr,
        &dev_attr_preferred_role.attr,
        &dev_attr_supported_accessory_modes.attr,
        &dev_attr_usb_power_delivery_revision.attr,
        &dev_attr_usb_typec_revision.attr,
        &dev_attr_vconn_source.attr,
        &dev_attr_port_type.attr,
        NULL,
};
ATTRIBUTE_GROUPS(typec);

static int typec_uevent(struct device *dev, struct kobj_uevent_env *env)
{
        int ret;

        ret = add_uevent_var(env, "TYPEC_PORT=%s", dev_name(dev));
        if (ret)
                dev_err(dev, "failed to add uevent TYPEC_PORT\n");

        return ret;
}

static void typec_release(struct device *dev)
{
        struct typec_port *port = to_typec_port(dev);

        ida_simple_remove(&typec_index_ida, port->id);
        ida_destroy(&port->mode_ids);
        typec_switch_put(port->sw);
        typec_mux_put(port->mux);
        kfree(port->cap);
        kfree(port);
}

const struct device_type typec_port_dev_type = {
        .name = "typec_port",
        .groups = typec_groups,
        .uevent = typec_uevent,
        .release = typec_release,
};

/* --------------------------------------- */
/* Driver callbacks to report role updates */

/**
 * typec_set_data_role - Report data role change
 * @port: The USB Type-C Port where the role was changed
 * @role: The new data role
 *
 * This routine is used by the port drivers to report data role changes.
 */
void typec_set_data_role(struct typec_port *port, enum typec_data_role role)
{
        if (port->data_role == role)
                return;

        port->data_role = role;
        sysfs_notify(&port->dev.kobj, NULL, "data_role");
        kobject_uevent(&port->dev.kobj, KOBJ_CHANGE);
}
EXPORT_SYMBOL_GPL(typec_set_data_role);

/**
 * typec_set_pwr_role - Report power role change
 * @port: The USB Type-C Port where the role was changed
 * @role: The new data role
 *
 * This routine is used by the port drivers to report power role changes.
 */
void typec_set_pwr_role(struct typec_port *port, enum typec_role role)
{
        if (port->pwr_role == role)
                return;

        port->pwr_role = role;
        sysfs_notify(&port->dev.kobj, NULL, "power_role");
        kobject_uevent(&port->dev.kobj, KOBJ_CHANGE);
}
EXPORT_SYMBOL_GPL(typec_set_pwr_role);

/**
 * typec_set_vconn_role - Report VCONN source change
 * @port: The USB Type-C Port which VCONN role changed
 * @role: Source when @port is sourcing VCONN, or Sink when it's not
 *
 * This routine is used by the port drivers to report if the VCONN source is
 * changes.
 */
void typec_set_vconn_role(struct typec_port *port, enum typec_role role)
{
        if (port->vconn_role == role)
                return;

        port->vconn_role = role;
        sysfs_notify(&port->dev.kobj, NULL, "vconn_source");
        kobject_uevent(&port->dev.kobj, KOBJ_CHANGE);
}
EXPORT_SYMBOL_GPL(typec_set_vconn_role);

static int partner_match(struct device *dev, void *data)
{
        return is_typec_partner(dev);
}

/**
 * typec_set_pwr_opmode - Report changed power operation mode
 * @port: The USB Type-C Port where the mode was changed
 * @opmode: New power operation mode
 *
 * This routine is used by the port drivers to report changed power operation
 * mode in @port. The modes are USB (default), 1.5A, 3.0A as defined in USB
 * Type-C specification, and "USB Power Delivery" when the power levels are
 * negotiated with methods defined in USB Power Delivery specification.
 */
void typec_set_pwr_opmode(struct typec_port *port,
                          enum typec_pwr_opmode opmode)
{
        struct device *partner_dev;

        if (port->pwr_opmode == opmode)
                return;

        port->pwr_opmode = opmode;
        sysfs_notify(&port->dev.kobj, NULL, "power_operation_mode");
        kobject_uevent(&port->dev.kobj, KOBJ_CHANGE);

        partner_dev = device_find_child(&port->dev, NULL, partner_match);
        if (partner_dev) {
                struct typec_partner *partner = to_typec_partner(partner_dev);

                if (opmode == TYPEC_PWR_MODE_PD && !partner->usb_pd) {
                        partner->usb_pd = 1;
                        sysfs_notify(&partner_dev->kobj, NULL,
                                     "supports_usb_power_delivery");
                }
                put_device(partner_dev);
        }
}
EXPORT_SYMBOL_GPL(typec_set_pwr_opmode);

/**
 * typec_find_port_power_role - Get the typec port power capability
 * @name: port power capability string
 *
 * This routine is used to find the typec_port_type by its string name.
 *
 * Returns typec_port_type if success, otherwise negative error code.
 */
int typec_find_port_power_role(const char *name)
{
        return match_string(typec_port_power_roles,
                            ARRAY_SIZE(typec_port_power_roles), name);
}
EXPORT_SYMBOL_GPL(typec_find_port_power_role);

/**
 * typec_find_power_role - Find the typec one specific power role
 * @name: power role string
 *
 * This routine is used to find the typec_role by its string name.
 *
 * Returns typec_role if success, otherwise negative error code.
 */
int typec_find_power_role(const char *name)
{
        return match_string(typec_roles, ARRAY_SIZE(typec_roles), name);
}
EXPORT_SYMBOL_GPL(typec_find_power_role);

/**
 * typec_find_port_data_role - Get the typec port data capability
 * @name: port data capability string
 *
 * This routine is used to find the typec_port_data by its string name.
 *
 * Returns typec_port_data if success, otherwise negative error code.
 */
int typec_find_port_data_role(const char *name)
{
        return match_string(typec_port_data_roles,
                            ARRAY_SIZE(typec_port_data_roles), name);
}
EXPORT_SYMBOL_GPL(typec_find_port_data_role);

/* ------------------------------------------ */
/* API for Multiplexer/DeMultiplexer Switches */

/**
 * typec_set_orientation - Set USB Type-C cable plug orientation
 * @port: USB Type-C Port
 * @orientation: USB Type-C cable plug orientation
 *
 * Set cable plug orientation for @port.
 */
int typec_set_orientation(struct typec_port *port,
                          enum typec_orientation orientation)
{
        int ret;

        if (port->sw) {
                ret = port->sw->set(port->sw, orientation);
                if (ret)
                        return ret;
        }

        port->orientation = orientation;

        return 0;
}
EXPORT_SYMBOL_GPL(typec_set_orientation);

/**
 * typec_get_orientation - Get USB Type-C cable plug orientation
 * @port: USB Type-C Port
 *
 * Get current cable plug orientation for @port.
 */
enum typec_orientation typec_get_orientation(struct typec_port *port)
{
        return port->orientation;
}
EXPORT_SYMBOL_GPL(typec_get_orientation);

/**
 * typec_set_mode - Set mode of operation for USB Type-C connector
 * @port: USB Type-C connector
 * @mode: Accessory Mode, USB Operation or Safe State
 *
 * Configure @port for Accessory Mode @mode. This function will configure the
 * muxes needed for @mode.
 */
int typec_set_mode(struct typec_port *port, int mode)
{
        struct typec_mux_state state = { };

        state.mode = mode;

        return port->mux ? port->mux->set(port->mux, &state) : 0;
}
EXPORT_SYMBOL_GPL(typec_set_mode);

/* --------------------------------------- */

/**
 * typec_get_drvdata - Return private driver data pointer
 * @port: USB Type-C port
 */
void *typec_get_drvdata(struct typec_port *port)
{
        return dev_get_drvdata(&port->dev);
}
EXPORT_SYMBOL_GPL(typec_get_drvdata);

/**
 * typec_port_register_altmode - Register USB Type-C Port Alternate Mode
 * @port: USB Type-C Port that supports the alternate mode
 * @desc: Description of the alternate mode
 *
 * This routine is used to register an alternate mode that @port is capable of
 * supporting.
 *
 * Returns handle to the alternate mode on success or ERR_PTR on failure.
 */
struct typec_altmode *
typec_port_register_altmode(struct typec_port *port,
                            const struct typec_altmode_desc *desc)
{
        struct typec_altmode *adev;
        struct typec_mux *mux;

        mux = typec_mux_get(&port->dev, desc);
        if (IS_ERR(mux))
                return ERR_CAST(mux);

        adev = typec_register_altmode(&port->dev, desc);
        if (IS_ERR(adev))
                typec_mux_put(mux);
        else
                to_altmode(adev)->mux = mux;

        return adev;
}
EXPORT_SYMBOL_GPL(typec_port_register_altmode);

/**
 * typec_register_port - Register a USB Type-C Port
 * @parent: Parent device
 * @cap: Description of the port
 *
 * Registers a device for USB Type-C Port described in @cap.
 *
 * Returns handle to the port on success or ERR_PTR on failure.
 */
struct typec_port *typec_register_port(struct device *parent,
                                       const struct typec_capability *cap)
{
        struct typec_port *port;
        int ret;
        int id;

        port = kzalloc(sizeof(*port), GFP_KERNEL);
        if (!port)
                return ERR_PTR(-ENOMEM);

        id = ida_simple_get(&typec_index_ida, 0, 0, GFP_KERNEL);
        if (id < 0) {
                kfree(port);
                return ERR_PTR(id);
        }

        switch (cap->type) {
        case TYPEC_PORT_SRC:
                port->pwr_role = TYPEC_SOURCE;
                port->vconn_role = TYPEC_SOURCE;
                break;
        case TYPEC_PORT_SNK:
                port->pwr_role = TYPEC_SINK;
                port->vconn_role = TYPEC_SINK;
                break;
        case TYPEC_PORT_DRP:
                if (cap->prefer_role != TYPEC_NO_PREFERRED_ROLE)
                        port->pwr_role = cap->prefer_role;
                else
                        port->pwr_role = TYPEC_SINK;
                break;
        }

        switch (cap->data) {
        case TYPEC_PORT_DFP:
                port->data_role = TYPEC_HOST;
                break;
        case TYPEC_PORT_UFP:
                port->data_role = TYPEC_DEVICE;
                break;
        case TYPEC_PORT_DRD:
                if (cap->prefer_role == TYPEC_SOURCE)
                        port->data_role = TYPEC_HOST;
                else
                        port->data_role = TYPEC_DEVICE;
                break;
        }

        ida_init(&port->mode_ids);
        mutex_init(&port->port_type_lock);

        port->id = id;
        port->ops = cap->ops;
        port->port_type = cap->type;
        port->prefer_role = cap->prefer_role;

        device_initialize(&port->dev);
        port->dev.class = typec_class;
        port->dev.parent = parent;
        port->dev.fwnode = cap->fwnode;
        port->dev.type = &typec_port_dev_type;
        dev_set_name(&port->dev, "port%d", id);
        dev_set_drvdata(&port->dev, cap->driver_data);

        port->cap = kmemdup(cap, sizeof(*cap), GFP_KERNEL);
        if (!port->cap) {
                put_device(&port->dev);
                return ERR_PTR(-ENOMEM);
        }

        port->sw = typec_switch_get(&port->dev);
        if (IS_ERR(port->sw)) {
                ret = PTR_ERR(port->sw);
                put_device(&port->dev);
                return ERR_PTR(ret);
        }

        port->mux = typec_mux_get(&port->dev, NULL);
        if (IS_ERR(port->mux)) {
                ret = PTR_ERR(port->mux);
                put_device(&port->dev);
                return ERR_PTR(ret);
        }

        ret = device_add(&port->dev);
        if (ret) {
                dev_err(parent, "failed to register port (%d)\n", ret);
                put_device(&port->dev);
                return ERR_PTR(ret);
        }

        return port;
}
EXPORT_SYMBOL_GPL(typec_register_port);

/**
 * typec_unregister_port - Unregister a USB Type-C Port
 * @port: The port to be unregistered
 *
 * Unregister device created with typec_register_port().
 */
void typec_unregister_port(struct typec_port *port)
{
        if (!IS_ERR_OR_NULL(port))
                device_unregister(&port->dev);
}
EXPORT_SYMBOL_GPL(typec_unregister_port);

static int __init typec_init(void)
{
        int ret;

        ret = bus_register(&typec_bus);
        if (ret)
                return ret;

        ret = class_register(&typec_mux_class);
        if (ret)
                goto err_unregister_bus;

        typec_class = class_create(THIS_MODULE, "typec");
        if (IS_ERR(typec_class)) {
                ret = PTR_ERR(typec_class);
                goto err_unregister_mux_class;
        }

        return 0;

err_unregister_mux_class:
        class_unregister(&typec_mux_class);

err_unregister_bus:
        bus_unregister(&typec_bus);

        return ret;
}
subsys_initcall(typec_init);

static void __exit typec_exit(void)
{
        class_destroy(typec_class);
        ida_destroy(&typec_index_ida);
        bus_unregister(&typec_bus);
        class_unregister(&typec_mux_class);
}
module_exit(typec_exit);

MODULE_AUTHOR("Heikki Krogerus <heikki.krogerus@linux.intel.com>");
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("USB Type-C Connector Class");