linux/drivers/thunderbolt/clx.c

// SPDX-License-Identifier: GPL-2.0
/*
 * CLx support
 *
 * Copyright (C) 2020 - 2023, Intel Corporation
 * Authors: Gil Fine <[email protected]>
 *	    Mika Westerberg <[email protected]>
 */

#include <linux/module.h>

#include "tb.h"

static bool clx_enabled = …;
module_param_named(clx, clx_enabled, bool, 0444);
MODULE_PARM_DESC(…) …;

static const char *clx_name(unsigned int clx)
{ … }

static int tb_port_pm_secondary_set(struct tb_port *port, bool secondary)
{ … }

static int tb_port_pm_secondary_enable(struct tb_port *port)
{ … }

static int tb_port_pm_secondary_disable(struct tb_port *port)
{ … }

/* Called for USB4 or Titan Ridge routers only */
static bool tb_port_clx_supported(struct tb_port *port, unsigned int clx)
{ … }

static int tb_port_clx_set(struct tb_port *port, unsigned int clx, bool enable)
{ … }

static int tb_port_clx_disable(struct tb_port *port, unsigned int clx)
{ … }

static int tb_port_clx_enable(struct tb_port *port, unsigned int clx)
{ … }

static int tb_port_clx(struct tb_port *port)
{ … }

/**
 * tb_port_clx_is_enabled() - Is given CL state enabled
 * @port: USB4 port to check
 * @clx: Mask of CL states to check
 *
 * Returns true if any of the given CL states is enabled for @port.
 */
bool tb_port_clx_is_enabled(struct tb_port *port, unsigned int clx)
{ … }

/**
 * tb_switch_clx_is_supported() - Is CLx supported on this type of router
 * @sw: The router to check CLx support for
 */
static bool tb_switch_clx_is_supported(const struct tb_switch *sw)
{ … }

/**
 * tb_switch_clx_init() - Initialize router CL states
 * @sw: Router
 *
 * Can be called for any router. Initializes the current CL state by
 * reading it from the hardware.
 *
 * Returns %0 in case of success and negative errno in case of failure.
 */
int tb_switch_clx_init(struct tb_switch *sw)
{ … }

static int tb_switch_pm_secondary_resolve(struct tb_switch *sw)
{ … }

static int tb_switch_mask_clx_objections(struct tb_switch *sw)
{ … }

static bool validate_mask(unsigned int clx)
{ … }

/**
 * tb_switch_clx_enable() - Enable CLx on upstream port of specified router
 * @sw: Router to enable CLx for
 * @clx: The CLx state to enable
 *
 * CLx is enabled only if both sides of the link support CLx, and if both sides
 * of the link are not configured as two single lane links and only if the link
 * is not inter-domain link. The complete set of conditions is described in CM
 * Guide 1.0 section 8.1.
 *
 * Returns %0 on success or an error code on failure.
 */
int tb_switch_clx_enable(struct tb_switch *sw, unsigned int clx)
{ … }

/**
 * tb_switch_clx_disable() - Disable CLx on upstream port of specified router
 * @sw: Router to disable CLx for
 *
 * Disables all CL states of the given router. Can be called on any
 * router and if the states were not enabled already does nothing.
 *
 * Returns the CL states that were disabled or negative errno in case of
 * failure.
 */
int tb_switch_clx_disable(struct tb_switch *sw)
{ … }