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https://github.com/AuxXxilium/linux_dsm_epyc7002.git
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e5256194cb
The switch devices have been named by using the name of the parent device as base for now, but if for example the parent device controls multiple muxes, that will not work. Adding an optional member "name" to the switch descriptor that can be used for naming the switch during registration. Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Link: https://lore.kernel.org/r/20200302135353.56659-7-heikki.krogerus@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
399 lines
9.5 KiB
C
399 lines
9.5 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* USB Role Switch Support
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*
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* Copyright (C) 2018 Intel Corporation
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* Author: Heikki Krogerus <heikki.krogerus@linux.intel.com>
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* Hans de Goede <hdegoede@redhat.com>
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*/
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#include <linux/usb/role.h>
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#include <linux/property.h>
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#include <linux/device.h>
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#include <linux/module.h>
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#include <linux/mutex.h>
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#include <linux/slab.h>
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static struct class *role_class;
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struct usb_role_switch {
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struct device dev;
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struct mutex lock; /* device lock*/
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enum usb_role role;
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/* From descriptor */
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struct device *usb2_port;
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struct device *usb3_port;
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struct device *udc;
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usb_role_switch_set_t set;
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usb_role_switch_get_t get;
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bool allow_userspace_control;
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};
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#define to_role_switch(d) container_of(d, struct usb_role_switch, dev)
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/**
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* usb_role_switch_set_role - Set USB role for a switch
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* @sw: USB role switch
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* @role: USB role to be switched to
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*
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* Set USB role @role for @sw.
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*/
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int usb_role_switch_set_role(struct usb_role_switch *sw, enum usb_role role)
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{
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int ret;
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if (IS_ERR_OR_NULL(sw))
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return 0;
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mutex_lock(&sw->lock);
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ret = sw->set(sw, role);
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if (!ret)
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sw->role = role;
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mutex_unlock(&sw->lock);
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return ret;
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}
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EXPORT_SYMBOL_GPL(usb_role_switch_set_role);
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/**
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* usb_role_switch_get_role - Get the USB role for a switch
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* @sw: USB role switch
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*
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* Depending on the role-switch-driver this function returns either a cached
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* value of the last set role, or reads back the actual value from the hardware.
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*/
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enum usb_role usb_role_switch_get_role(struct usb_role_switch *sw)
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{
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enum usb_role role;
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if (IS_ERR_OR_NULL(sw))
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return USB_ROLE_NONE;
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mutex_lock(&sw->lock);
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if (sw->get)
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role = sw->get(sw);
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else
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role = sw->role;
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mutex_unlock(&sw->lock);
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return role;
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}
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EXPORT_SYMBOL_GPL(usb_role_switch_get_role);
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static void *usb_role_switch_match(struct device_connection *con, int ep,
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void *data)
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{
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struct device *dev;
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if (con->fwnode) {
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if (con->id && !fwnode_property_present(con->fwnode, con->id))
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return NULL;
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dev = class_find_device_by_fwnode(role_class, con->fwnode);
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} else {
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dev = class_find_device_by_name(role_class, con->endpoint[ep]);
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}
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return dev ? to_role_switch(dev) : ERR_PTR(-EPROBE_DEFER);
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}
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static struct usb_role_switch *
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usb_role_switch_is_parent(struct fwnode_handle *fwnode)
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{
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struct fwnode_handle *parent = fwnode_get_parent(fwnode);
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struct device *dev;
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if (!parent || !fwnode_property_present(parent, "usb-role-switch"))
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return NULL;
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dev = class_find_device_by_fwnode(role_class, parent);
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return dev ? to_role_switch(dev) : ERR_PTR(-EPROBE_DEFER);
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}
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/**
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* usb_role_switch_get - Find USB role switch linked with the caller
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* @dev: The caller device
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*
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* Finds and returns role switch linked with @dev. The reference count for the
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* found switch is incremented.
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*/
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struct usb_role_switch *usb_role_switch_get(struct device *dev)
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{
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struct usb_role_switch *sw;
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sw = usb_role_switch_is_parent(dev_fwnode(dev));
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if (!sw)
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sw = device_connection_find_match(dev, "usb-role-switch", NULL,
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usb_role_switch_match);
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if (!IS_ERR_OR_NULL(sw))
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WARN_ON(!try_module_get(sw->dev.parent->driver->owner));
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return sw;
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}
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EXPORT_SYMBOL_GPL(usb_role_switch_get);
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/**
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* fwnode_usb_role_switch_get - Find USB role switch linked with the caller
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* @fwnode: The caller device node
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*
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* This is similar to the usb_role_switch_get() function above, but it searches
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* the switch using fwnode instead of device entry.
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*/
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struct usb_role_switch *fwnode_usb_role_switch_get(struct fwnode_handle *fwnode)
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{
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struct usb_role_switch *sw;
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sw = usb_role_switch_is_parent(fwnode);
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if (!sw)
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sw = fwnode_connection_find_match(fwnode, "usb-role-switch",
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NULL, usb_role_switch_match);
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if (!IS_ERR_OR_NULL(sw))
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WARN_ON(!try_module_get(sw->dev.parent->driver->owner));
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return sw;
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}
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EXPORT_SYMBOL_GPL(fwnode_usb_role_switch_get);
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/**
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* usb_role_switch_put - Release handle to a switch
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* @sw: USB Role Switch
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*
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* Decrement reference count for @sw.
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*/
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void usb_role_switch_put(struct usb_role_switch *sw)
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{
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if (!IS_ERR_OR_NULL(sw)) {
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module_put(sw->dev.parent->driver->owner);
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put_device(&sw->dev);
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}
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}
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EXPORT_SYMBOL_GPL(usb_role_switch_put);
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/**
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* usb_role_switch_find_by_fwnode - Find USB role switch with its fwnode
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* @fwnode: fwnode of the USB Role Switch
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*
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* Finds and returns role switch with @fwnode. The reference count for the
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* found switch is incremented.
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*/
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struct usb_role_switch *
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usb_role_switch_find_by_fwnode(const struct fwnode_handle *fwnode)
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{
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struct device *dev;
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if (!fwnode)
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return NULL;
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dev = class_find_device_by_fwnode(role_class, fwnode);
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return dev ? to_role_switch(dev) : NULL;
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}
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EXPORT_SYMBOL_GPL(usb_role_switch_find_by_fwnode);
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static umode_t
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usb_role_switch_is_visible(struct kobject *kobj, struct attribute *attr, int n)
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{
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struct device *dev = kobj_to_dev(kobj);
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struct usb_role_switch *sw = to_role_switch(dev);
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if (sw->allow_userspace_control)
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return attr->mode;
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return 0;
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}
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static const char * const usb_roles[] = {
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[USB_ROLE_NONE] = "none",
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[USB_ROLE_HOST] = "host",
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[USB_ROLE_DEVICE] = "device",
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};
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static ssize_t
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role_show(struct device *dev, struct device_attribute *attr, char *buf)
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{
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struct usb_role_switch *sw = to_role_switch(dev);
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enum usb_role role = usb_role_switch_get_role(sw);
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return sprintf(buf, "%s\n", usb_roles[role]);
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}
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static ssize_t role_store(struct device *dev, struct device_attribute *attr,
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const char *buf, size_t size)
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{
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struct usb_role_switch *sw = to_role_switch(dev);
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int ret;
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ret = sysfs_match_string(usb_roles, buf);
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if (ret < 0) {
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bool res;
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/* Extra check if the user wants to disable the switch */
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ret = kstrtobool(buf, &res);
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if (ret || res)
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return -EINVAL;
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}
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ret = usb_role_switch_set_role(sw, ret);
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if (ret)
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return ret;
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return size;
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}
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static DEVICE_ATTR_RW(role);
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static struct attribute *usb_role_switch_attrs[] = {
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&dev_attr_role.attr,
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NULL,
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};
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static const struct attribute_group usb_role_switch_group = {
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.is_visible = usb_role_switch_is_visible,
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.attrs = usb_role_switch_attrs,
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};
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static const struct attribute_group *usb_role_switch_groups[] = {
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&usb_role_switch_group,
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NULL,
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};
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static int
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usb_role_switch_uevent(struct device *dev, struct kobj_uevent_env *env)
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{
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int ret;
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ret = add_uevent_var(env, "USB_ROLE_SWITCH=%s", dev_name(dev));
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if (ret)
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dev_err(dev, "failed to add uevent USB_ROLE_SWITCH\n");
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return ret;
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}
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static void usb_role_switch_release(struct device *dev)
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{
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struct usb_role_switch *sw = to_role_switch(dev);
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kfree(sw);
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}
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static const struct device_type usb_role_dev_type = {
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.name = "usb_role_switch",
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.groups = usb_role_switch_groups,
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.uevent = usb_role_switch_uevent,
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.release = usb_role_switch_release,
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};
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/**
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* usb_role_switch_register - Register USB Role Switch
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* @parent: Parent device for the switch
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* @desc: Description of the switch
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*
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* USB Role Switch is a device capable or choosing the role for USB connector.
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* On platforms where the USB controller is dual-role capable, the controller
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* driver will need to register the switch. On platforms where the USB host and
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* USB device controllers behind the connector are separate, there will be a
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* mux, and the driver for that mux will need to register the switch.
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*
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* Returns handle to a new role switch or ERR_PTR. The content of @desc is
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* copied.
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*/
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struct usb_role_switch *
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usb_role_switch_register(struct device *parent,
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const struct usb_role_switch_desc *desc)
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{
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struct usb_role_switch *sw;
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int ret;
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if (!desc || !desc->set)
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return ERR_PTR(-EINVAL);
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sw = kzalloc(sizeof(*sw), GFP_KERNEL);
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if (!sw)
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return ERR_PTR(-ENOMEM);
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mutex_init(&sw->lock);
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sw->allow_userspace_control = desc->allow_userspace_control;
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sw->usb2_port = desc->usb2_port;
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sw->usb3_port = desc->usb3_port;
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sw->udc = desc->udc;
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sw->set = desc->set;
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sw->get = desc->get;
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sw->dev.parent = parent;
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sw->dev.fwnode = desc->fwnode;
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sw->dev.class = role_class;
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sw->dev.type = &usb_role_dev_type;
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dev_set_drvdata(&sw->dev, desc->driver_data);
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dev_set_name(&sw->dev, "%s-role-switch",
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desc->name ? desc->name : dev_name(parent));
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ret = device_register(&sw->dev);
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if (ret) {
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put_device(&sw->dev);
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return ERR_PTR(ret);
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}
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/* TODO: Symlinks for the host port and the device controller. */
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return sw;
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}
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EXPORT_SYMBOL_GPL(usb_role_switch_register);
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/**
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* usb_role_switch_unregister - Unregsiter USB Role Switch
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* @sw: USB Role Switch
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*
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* Unregister switch that was registered with usb_role_switch_register().
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*/
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void usb_role_switch_unregister(struct usb_role_switch *sw)
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{
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if (!IS_ERR_OR_NULL(sw))
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device_unregister(&sw->dev);
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}
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EXPORT_SYMBOL_GPL(usb_role_switch_unregister);
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/**
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* usb_role_switch_set_drvdata - Assign private data pointer to a switch
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* @sw: USB Role Switch
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* @data: Private data pointer
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*/
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void usb_role_switch_set_drvdata(struct usb_role_switch *sw, void *data)
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{
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dev_set_drvdata(&sw->dev, data);
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}
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EXPORT_SYMBOL_GPL(usb_role_switch_set_drvdata);
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/**
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* usb_role_switch_get_drvdata - Get the private data pointer of a switch
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* @sw: USB Role Switch
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*/
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void *usb_role_switch_get_drvdata(struct usb_role_switch *sw)
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{
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return dev_get_drvdata(&sw->dev);
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}
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EXPORT_SYMBOL_GPL(usb_role_switch_get_drvdata);
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static int __init usb_roles_init(void)
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{
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role_class = class_create(THIS_MODULE, "usb_role");
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return PTR_ERR_OR_ZERO(role_class);
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}
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subsys_initcall(usb_roles_init);
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static void __exit usb_roles_exit(void)
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{
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class_destroy(role_class);
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}
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module_exit(usb_roles_exit);
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MODULE_AUTHOR("Heikki Krogerus <heikki.krogerus@linux.intel.com>");
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MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
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MODULE_LICENSE("GPL v2");
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MODULE_DESCRIPTION("USB Role Class");
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