pty: Repair TIOCGPTPEER

[cris-mirror.git] / drivers / usb / typec / typec.c

/*
 * USB Type-C Connector Class
 *
 * Copyright (C) 2017, Intel Corporation
 * Author: Heikki Krogerus <heikki.krogerus@linux.intel.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

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

struct typec_mode {
        int                             index;
        u32                             vdo;
        char                            *desc;
        enum typec_port_type            roles;

        struct typec_altmode            *alt_mode;

        unsigned int                    active:1;

        char                            group_name[6];
        struct attribute_group          group;
        struct attribute                *attrs[5];
        struct device_attribute         vdo_attr;
        struct device_attribute         desc_attr;
        struct device_attribute         active_attr;
        struct device_attribute         roles_attr;
};

struct typec_altmode {
        struct device                   dev;
        u16                             svid;
        int                             n_modes;
        struct typec_mode               modes[ALTMODE_MAX_MODES];
        const struct attribute_group    *mode_groups[ALTMODE_MAX_MODES];
};

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

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 typec_port {
        unsigned int                    id;
        struct device                   dev;

        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;

        const struct typec_capability   *cap;
};

#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)
#define to_altmode(_dev_) container_of(_dev_, struct typec_altmode, 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;
static const struct device_type typec_port_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)
#define is_typec_port(_dev_) (_dev_->type == &typec_port_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 */

/**
 * typec_altmode_update_active - Report Enter/Exit mode
 * @alt: Handle to the alternate mode
 * @mode: Mode index
 * @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 *alt, int mode,
                                 bool active)
{
        struct typec_mode *m = &alt->modes[mode];
        char dir[6];

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

        m->active = active;
        snprintf(dir, sizeof(dir), "mode%d", mode);
        sysfs_notify(&alt->dev.kobj, dir, "active");
        kobject_uevent(&alt->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
typec_altmode_vdo_show(struct device *dev, struct device_attribute *attr,
                       char *buf)
{
        struct typec_mode *mode = container_of(attr, struct typec_mode,
                                               vdo_attr);

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

static ssize_t
typec_altmode_desc_show(struct device *dev, struct device_attribute *attr,
                        char *buf)
{
        struct typec_mode *mode = container_of(attr, struct typec_mode,
                                               desc_attr);

        return sprintf(buf, "%s\n", mode->desc ? mode->desc : "");
}

static ssize_t
typec_altmode_active_show(struct device *dev, struct device_attribute *attr,
                          char *buf)
{
        struct typec_mode *mode = container_of(attr, struct typec_mode,
                                               active_attr);

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

static ssize_t
typec_altmode_active_store(struct device *dev, struct device_attribute *attr,
                           const char *buf, size_t size)
{
        struct typec_mode *mode = container_of(attr, struct typec_mode,
                                               active_attr);
        struct typec_port *port = typec_altmode2port(mode->alt_mode);
        bool activate;
        int ret;

        if (!port->cap->activate_mode)
                return -EOPNOTSUPP;

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

        ret = port->cap->activate_mode(port->cap, mode->index, activate);
        if (ret)
                return ret;

        return size;
}

static ssize_t
typec_altmode_roles_show(struct device *dev, struct device_attribute *attr,
                         char *buf)
{
        struct typec_mode *mode = container_of(attr, struct typec_mode,
                                               roles_attr);
        ssize_t ret;

        switch (mode->roles) {
        case TYPEC_PORT_DFP:
                ret = sprintf(buf, "source\n");
                break;
        case TYPEC_PORT_UFP:
                ret = sprintf(buf, "sink\n");
                break;
        case TYPEC_PORT_DRP:
        default:
                ret = sprintf(buf, "source sink\n");
                break;
        }
        return ret;
}

static void typec_init_modes(struct typec_altmode *alt,
                             const struct typec_mode_desc *desc, bool is_port)
{
        int i;

        for (i = 0; i < alt->n_modes; i++, desc++) {
                struct typec_mode *mode = &alt->modes[i];

                /* Not considering the human readable description critical */
                mode->desc = kstrdup(desc->desc, GFP_KERNEL);
                if (desc->desc && !mode->desc)
                        dev_err(&alt->dev, "failed to copy mode%d desc\n", i);

                mode->alt_mode = alt;
                mode->vdo = desc->vdo;
                mode->roles = desc->roles;
                mode->index = desc->index;
                sprintf(mode->group_name, "mode%d", desc->index);

                sysfs_attr_init(&mode->vdo_attr.attr);
                mode->vdo_attr.attr.name = "vdo";
                mode->vdo_attr.attr.mode = 0444;
                mode->vdo_attr.show = typec_altmode_vdo_show;

                sysfs_attr_init(&mode->desc_attr.attr);
                mode->desc_attr.attr.name = "description";
                mode->desc_attr.attr.mode = 0444;
                mode->desc_attr.show = typec_altmode_desc_show;

                sysfs_attr_init(&mode->active_attr.attr);
                mode->active_attr.attr.name = "active";
                mode->active_attr.attr.mode = 0644;
                mode->active_attr.show = typec_altmode_active_show;
                mode->active_attr.store = typec_altmode_active_store;

                mode->attrs[0] = &mode->vdo_attr.attr;
                mode->attrs[1] = &mode->desc_attr.attr;
                mode->attrs[2] = &mode->active_attr.attr;

                /* With ports, list the roles that the mode is supported with */
                if (is_port) {
                        sysfs_attr_init(&mode->roles_attr.attr);
                        mode->roles_attr.attr.name = "supported_roles";
                        mode->roles_attr.attr.mode = 0444;
                        mode->roles_attr.show = typec_altmode_roles_show;

                        mode->attrs[3] = &mode->roles_attr.attr;
                }

                mode->group.attrs = mode->attrs;
                mode->group.name = mode->group_name;

                alt->mode_groups[i] = &mode->group;
        }
}

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

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

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

static void typec_altmode_release(struct device *dev)
{
        struct typec_altmode *alt = to_altmode(dev);
        int i;

        for (i = 0; i < alt->n_modes; i++)
                kfree(alt->modes[i].desc);
        kfree(alt);
}

static 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)
{
        struct typec_altmode *alt;
        int ret;

        alt = kzalloc(sizeof(*alt), GFP_KERNEL);
        if (!alt)
                return NULL;

        alt->svid = desc->svid;
        alt->n_modes = desc->n_modes;
        typec_init_modes(alt, desc->modes, is_typec_port(parent));

        alt->dev.parent = parent;
        alt->dev.groups = alt->mode_groups;
        alt->dev.type = &typec_altmode_dev_type;
        dev_set_name(&alt->dev, "svid-%04x", alt->svid);

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

        return alt;
}

/**
 * typec_unregister_altmode - Unregister Alternate Mode
 * @alt: 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 *alt)
{
        if (alt)
                device_unregister(&alt->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);

        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 NULL 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 NULL;

        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 NULL;
        }

        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 (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);

        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 NULL 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 NULL 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 NULL;

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

        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 NULL;
        }

        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 (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,
};

/**
 * 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 NULL 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 NULL;

        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 NULL;
        }

        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 (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_types[] = {
        [TYPEC_PORT_DFP] = "source",
        [TYPEC_PORT_UFP] = "sink",
        [TYPEC_PORT_DRP] = "dual",
};

static const char * const typec_port_types_drp[] = {
        [TYPEC_PORT_DFP] = "dual [source] sink",
        [TYPEC_PORT_UFP] = "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->cap->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->cap->try_role(port->cap, 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->cap->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->port_type != TYPEC_PORT_DRP) {
                dev_dbg(dev, "port type fixed at \"%s\"",
                             typec_port_types[port->port_type]);
                ret = -EOPNOTSUPP;
                goto unlock_and_ret;
        }

        ret = port->cap->dr_set(port->cap, 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->type == TYPEC_PORT_DRP)
                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->cap->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_types[port->port_type]);
                ret = -EOPNOTSUPP;
                goto unlock_and_ret;
        }

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

        ret = sysfs_match_string(typec_port_types, 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->cap->port_type_set(port->cap, 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_types[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->cap->vconn_set) {
                dev_dbg(dev, "VCONN swapping not supported\n");
                return -EOPNOTSUPP;
        }

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

        ret = port->cap->vconn_set(port->cap, (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);
        kfree(port);
}

static 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_pwr_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_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 NULL on failure.
 */
struct typec_altmode *
typec_port_register_altmode(struct typec_port *port,
                            const struct typec_altmode_desc *desc)
{
        return typec_register_altmode(&port->dev, desc);
}
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 NULL on failure.
 */
struct typec_port *typec_register_port(struct device *parent,
                                       const struct typec_capability *cap)
{
        struct typec_port *port;
        int role;
        int ret;
        int id;

        port = kzalloc(sizeof(*port), GFP_KERNEL);
        if (!port)
                return NULL;

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

        if (cap->type == TYPEC_PORT_DFP)
                role = TYPEC_SOURCE;
        else if (cap->type == TYPEC_PORT_UFP)
                role = TYPEC_SINK;
        else
                role = cap->prefer_role;

        if (role == TYPEC_SOURCE) {
                port->data_role = TYPEC_HOST;
                port->pwr_role = TYPEC_SOURCE;
                port->vconn_role = TYPEC_SOURCE;
        } else {
                port->data_role = TYPEC_DEVICE;
                port->pwr_role = TYPEC_SINK;
                port->vconn_role = TYPEC_SINK;
        }

        port->id = id;
        port->cap = cap;
        port->port_type = cap->type;
        mutex_init(&port->port_type_lock);
        port->prefer_role = cap->prefer_role;

        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);

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

        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 (port)
                device_unregister(&port->dev);
}
EXPORT_SYMBOL_GPL(typec_unregister_port);

static int __init typec_init(void)
{
        typec_class = class_create(THIS_MODULE, "typec");
        return PTR_ERR_OR_ZERO(typec_class);
}
subsys_initcall(typec_init);

static void __exit typec_exit(void)
{
        class_destroy(typec_class);
        ida_destroy(&typec_index_ida);
}
module_exit(typec_exit);

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