linux-imx

// SPDX-License-Identifier: GPL-2.0

/*

 * Thunderbolt driver - capabilities lookup

 *

 * Copyright (c) 2014 Andreas Noever <andreas.noever@gmail.com>

 * Copyright (C) 2018, Intel Corporation

 */

​

#include <linux/slab.h>

#include <linux/errno.h>

​

#include "tb.h"

​

#define CAP_OFFSET_MAX      0xff

#define VSE_CAP_OFFSET_MAX  0xffff

#define TMU_ACCESS_EN       BIT(20)

​

struct tb_cap_any {

    union {

        struct tb_cap_basic basic;

        struct tb_cap_extended_short extended_short;

        struct tb_cap_extended_long extended_long;

    };

} __packed;

​

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

{

    struct tb_switch *sw = port->sw;

    u32 value, offset;

    int ret;

​

    /*

     * Legacy devices need to have TMU access enabled before port

     * space can be fully accessed.

     */

    if (tb_switch_is_lr(sw))

        offset = 0x26;

    else if (tb_switch_is_er(sw))

        offset = 0x2a;

    else

        return 0;

​

    ret = tb_sw_read(sw, &value, TB_CFG_SWITCH, offset, 1);

    if (ret)

        return ret;

​

    if (enable)

        value |= TMU_ACCESS_EN;

    else

        value &= ~TMU_ACCESS_EN;

​

    return tb_sw_write(sw, &value, TB_CFG_SWITCH, offset, 1);

}

​

static void tb_port_dummy_read(struct tb_port *port)

{

    /*

     * When reading from next capability pointer location in port

     * config space the read data is not cleared on LR. To avoid

     * reading stale data on next read perform one dummy read after

     * port capabilities are walked.

     */

    if (tb_switch_is_lr(port->sw)) {