linux-imx

// SPDX-License-Identifier: GPL-2.0

/*

 * Thunderbolt driver - eeprom access

 *

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

 * Copyright (C) 2018, Intel Corporation

 */

​

#include <linux/crc32.h>

#include <linux/property.h>

#include <linux/slab.h>

#include "tb.h"

​

/**

 * tb_eeprom_ctl_write() - write control word

 */

static int tb_eeprom_ctl_write(struct tb_switch *sw, struct tb_eeprom_ctl *ctl)

{

    return tb_sw_write(sw, ctl, TB_CFG_SWITCH, sw->cap_plug_events + 4, 1);

}

​

/**

 * tb_eeprom_ctl_write() - read control word

 */

static int tb_eeprom_ctl_read(struct tb_switch *sw, struct tb_eeprom_ctl *ctl)

{

    return tb_sw_read(sw, ctl, TB_CFG_SWITCH, sw->cap_plug_events + 4, 1);

}

​

enum tb_eeprom_transfer {

    TB_EEPROM_IN,

    TB_EEPROM_OUT,

};

​

/**

 * tb_eeprom_active - enable rom access

 *

 * WARNING: Always disable access after usage. Otherwise the controller will

 * fail to reprobe.

 */

static int tb_eeprom_active(struct tb_switch *sw, bool enable)

{

    struct tb_eeprom_ctl ctl;

    int res = tb_eeprom_ctl_read(sw, &ctl);

    if (res)

        return res;

    if (enable) {

        ctl.access_high = 1;

        res = tb_eeprom_ctl_write(sw, &ctl);

        if (res)

            return res;

        ctl.access_low = 0;

        return tb_eeprom_ctl_write(sw, &ctl);

    } else {

        ctl.access_low = 1;

        res = tb_eeprom_ctl_write(sw, &ctl);

        if (res)

            return res;

        ctl.access_high = 0;

        return tb_eeprom_ctl_write(sw, &ctl);

    }

}

​