linux/drivers/thunderbolt/cap.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Thunderbolt driver - capabilities lookup
 *
 * Copyright (c) 2014 Andreas Noever <[email protected]>
 * Copyright (C) 2018, Intel Corporation
 */

#include <linux/slab.h>
#include <linux/errno.h>

#include "tb.h"

#define CAP_OFFSET_MAX …
#define VSE_CAP_OFFSET_MAX …
#define TMU_ACCESS_EN …

static int tb_port_enable_tmu(struct tb_port *port, bool enable)
{ … }

static void tb_port_dummy_read(struct tb_port *port)
{ … }

/**
 * tb_port_next_cap() - Return next capability in the linked list
 * @port: Port to find the capability for
 * @offset: Previous capability offset (%0 for start)
 *
 * Returns dword offset of the next capability in port config space
 * capability list and returns it. Passing %0 returns the first entry in
 * the capability list. If no next capability is found returns %0. In case
 * of failure returns negative errno.
 */
int tb_port_next_cap(struct tb_port *port, unsigned int offset)
{ … }

static int __tb_port_find_cap(struct tb_port *port, enum tb_port_cap cap)
{ … }

/**
 * tb_port_find_cap() - Find port capability
 * @port: Port to find the capability for
 * @cap: Capability to look
 *
 * Returns offset to start of capability or %-ENOENT if no such
 * capability was found. Negative errno is returned if there was an
 * error.
 */
int tb_port_find_cap(struct tb_port *port, enum tb_port_cap cap)
{ … }

/**
 * tb_switch_next_cap() - Return next capability in the linked list
 * @sw: Switch to find the capability for
 * @offset: Previous capability offset (%0 for start)
 *
 * Finds dword offset of the next capability in router config space
 * capability list and returns it. Passing %0 returns the first entry in
 * the capability list. If no next capability is found returns %0. In case
 * of failure returns negative errno.
 */
int tb_switch_next_cap(struct tb_switch *sw, unsigned int offset)
{ … }

/**
 * tb_switch_find_cap() - Find switch capability
 * @sw: Switch to find the capability for
 * @cap: Capability to look
 *
 * Returns offset to start of capability or %-ENOENT if no such
 * capability was found. Negative errno is returned if there was an
 * error.
 */
int tb_switch_find_cap(struct tb_switch *sw, enum tb_switch_cap cap)
{ … }

/**
 * tb_switch_find_vse_cap() - Find switch vendor specific capability
 * @sw: Switch to find the capability for
 * @vsec: Vendor specific capability to look
 *
 * Functions enumerates vendor specific capabilities (VSEC) of a switch
 * and returns offset when capability matching @vsec is found. If no
 * such capability is found returns %-ENOENT. In case of error returns
 * negative errno.
 */
int tb_switch_find_vse_cap(struct tb_switch *sw, enum tb_switch_vse_cap vsec)
{ … }