blob: 2ce54f3fc79c3af74094baebe073060c98e07f49 [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0
/**
* USB Type-C Multiplexer/DeMultiplexer Switch support
*
* Copyright (C) 2018 Intel Corporation
* Author: Heikki Krogerus <heikki.krogerus@linux.intel.com>
* Hans de Goede <hdegoede@redhat.com>
*/
#include <linux/device.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/property.h>
#include <linux/slab.h>
#include <linux/usb/typec_mux.h>
static DEFINE_MUTEX(switch_lock);
static DEFINE_MUTEX(mux_lock);
static LIST_HEAD(switch_list);
static LIST_HEAD(mux_list);
static void *typec_switch_match(struct device_connection *con, int ep,
void *data)
{
struct typec_switch *sw;
if (!con->fwnode) {
list_for_each_entry(sw, &switch_list, entry)
if (!strcmp(con->endpoint[ep], dev_name(sw->dev)))
return sw;
return ERR_PTR(-EPROBE_DEFER);
}
/*
* With OF graph the mux node must have a boolean device property named
* "orientation-switch".
*/
if (con->id && !fwnode_property_present(con->fwnode, con->id))
return NULL;
list_for_each_entry(sw, &switch_list, entry)
if (dev_fwnode(sw->dev) == con->fwnode)
return sw;
return con->id ? ERR_PTR(-EPROBE_DEFER) : NULL;
}
/**
* typec_switch_get - Find USB Type-C orientation switch
* @dev: The caller device
*
* Finds a switch linked with @dev. Returns a reference to the switch on
* success, NULL if no matching connection was found, or
* ERR_PTR(-EPROBE_DEFER) when a connection was found but the switch
* has not been enumerated yet.
*/
struct typec_switch *typec_switch_get(struct device *dev)
{
struct typec_switch *sw;
mutex_lock(&switch_lock);
sw = device_connection_find_match(dev, "orientation-switch", NULL,
typec_switch_match);
if (!IS_ERR_OR_NULL(sw)) {
WARN_ON(!try_module_get(sw->dev->driver->owner));
get_device(sw->dev);
}
mutex_unlock(&switch_lock);
return sw;
}
EXPORT_SYMBOL_GPL(typec_switch_get);
/**
* typec_put_switch - Release USB Type-C orientation switch
* @sw: USB Type-C orientation switch
*
* Decrement reference count for @sw.
*/
void typec_switch_put(struct typec_switch *sw)
{
if (!IS_ERR_OR_NULL(sw)) {
module_put(sw->dev->driver->owner);
put_device(sw->dev);
}
}
EXPORT_SYMBOL_GPL(typec_switch_put);
/**
* typec_switch_register - Register USB Type-C orientation switch
* @sw: USB Type-C orientation switch
*
* This function registers a switch that can be used for routing the correct
* data pairs depending on the cable plug orientation from the USB Type-C
* connector to the USB controllers. USB Type-C plugs can be inserted
* right-side-up or upside-down.
*/
int typec_switch_register(struct typec_switch *sw)
{
mutex_lock(&switch_lock);
list_add_tail(&sw->entry, &switch_list);
mutex_unlock(&switch_lock);
return 0;
}
EXPORT_SYMBOL_GPL(typec_switch_register);
/**
* typec_switch_unregister - Unregister USB Type-C orientation switch
* @sw: USB Type-C orientation switch
*
* Unregister switch that was registered with typec_switch_register().
*/
void typec_switch_unregister(struct typec_switch *sw)
{
mutex_lock(&switch_lock);
list_del(&sw->entry);
mutex_unlock(&switch_lock);
}
EXPORT_SYMBOL_GPL(typec_switch_unregister);
/* ------------------------------------------------------------------------- */
static void *typec_mux_match(struct device_connection *con, int ep, void *data)
{
const struct typec_altmode_desc *desc = data;
struct typec_mux *mux;
int nval;
bool match;
u16 *val;
int i;
if (!con->fwnode) {
list_for_each_entry(mux, &mux_list, entry)
if (!strcmp(con->endpoint[ep], dev_name(mux->dev)))
return mux;
return ERR_PTR(-EPROBE_DEFER);
}
/*
* Check has the identifier already been "consumed". If it
* has, no need to do any extra connection identification.
*/
match = !con->id;
if (match)
goto find_mux;
/* Accessory Mode muxes */
if (!desc) {
match = fwnode_property_present(con->fwnode, "accessory");
if (match)
goto find_mux;
return NULL;
}
/* Alternate Mode muxes */
nval = fwnode_property_read_u16_array(con->fwnode, "svid", NULL, 0);
if (nval <= 0)
return NULL;
val = kcalloc(nval, sizeof(*val), GFP_KERNEL);
if (!val)
return ERR_PTR(-ENOMEM);
nval = fwnode_property_read_u16_array(con->fwnode, "svid", val, nval);
if (nval < 0) {
kfree(val);
return ERR_PTR(nval);
}
for (i = 0; i < nval; i++) {
match = val[i] == desc->svid;
if (match) {
kfree(val);
goto find_mux;
}
}
kfree(val);
return NULL;
find_mux:
list_for_each_entry(mux, &mux_list, entry)
if (dev_fwnode(mux->dev) == con->fwnode)
return mux;
return ERR_PTR(-EPROBE_DEFER);
}
/**
* typec_mux_get - Find USB Type-C Multiplexer
* @dev: The caller device
* @desc: Alt Mode description
*
* Finds a mux linked to the caller. This function is primarily meant for the
* Type-C drivers. Returns a reference to the mux on success, NULL if no
* matching connection was found, or ERR_PTR(-EPROBE_DEFER) when a connection
* was found but the mux has not been enumerated yet.
*/
struct typec_mux *typec_mux_get(struct device *dev,
const struct typec_altmode_desc *desc)
{
struct typec_mux *mux;
mutex_lock(&mux_lock);
mux = device_connection_find_match(dev, "mode-switch", (void *)desc,
typec_mux_match);
if (!IS_ERR_OR_NULL(mux)) {
WARN_ON(!try_module_get(mux->dev->driver->owner));
get_device(mux->dev);
}
mutex_unlock(&mux_lock);
return mux;
}
EXPORT_SYMBOL_GPL(typec_mux_get);
/**
* typec_mux_put - Release handle to a Multiplexer
* @mux: USB Type-C Connector Multiplexer/DeMultiplexer
*
* Decrements reference count for @mux.
*/
void typec_mux_put(struct typec_mux *mux)
{
if (!IS_ERR_OR_NULL(mux)) {
module_put(mux->dev->driver->owner);
put_device(mux->dev);
}
}
EXPORT_SYMBOL_GPL(typec_mux_put);
/**
* typec_mux_register - Register Multiplexer routing USB Type-C pins
* @mux: USB Type-C Connector Multiplexer/DeMultiplexer
*
* USB Type-C connectors can be used for alternate modes of operation besides
* USB when Accessory/Alternate Modes are supported. With some of those modes,
* the pins on the connector need to be reconfigured. This function registers
* multiplexer switches routing the pins on the connector.
*/
int typec_mux_register(struct typec_mux *mux)
{
mutex_lock(&mux_lock);
list_add_tail(&mux->entry, &mux_list);
mutex_unlock(&mux_lock);
return 0;
}
EXPORT_SYMBOL_GPL(typec_mux_register);
/**
* typec_mux_unregister - Unregister Multiplexer Switch
* @mux: USB Type-C Connector Multiplexer/DeMultiplexer
*
* Unregister mux that was registered with typec_mux_register().
*/
void typec_mux_unregister(struct typec_mux *mux)
{
mutex_lock(&mux_lock);
list_del(&mux->entry);
mutex_unlock(&mux_lock);
}
EXPORT_SYMBOL_GPL(typec_mux_unregister);