linux-imx

// SPDX-License-Identifier: GPL-2.0+

/*

 * OTG Finite State Machine from OTG spec

 *

 * Copyright (C) 2007,2008 Freescale Semiconductor, Inc.

 *

 * Author:  Li Yang <LeoLi@freescale.com>

 *      Jerry Huang <Chang-Ming.Huang@freescale.com>

 */

​

#include <linux/module.h>

#include <linux/kernel.h>

#include <linux/types.h>

#include <linux/mutex.h>

#include <linux/delay.h>

#include <linux/usb.h>

#include <linux/usb/gadget.h>

#include <linux/usb/otg.h>

#include <linux/usb/otg-fsm.h>

​

#ifdef VERBOSE

#define VDBG(fmt, args...) pr_debug("[%s]  " fmt, \

                 __func__, ## args)

#else

#define VDBG(stuff...)  do {} while (0)

#endif

​

/* Change USB protocol when there is a protocol change */

static int otg_set_protocol(struct otg_fsm *fsm, int protocol)

{

    int ret = 0;

​

    if (fsm->protocol != protocol) {

        VDBG("Changing role fsm->protocol= %d; new protocol= %d\n",

            fsm->protocol, protocol);

        /* stop old protocol */

        if (fsm->protocol == PROTO_HOST)

            ret = otg_start_host(fsm, 0);

        else if (fsm->protocol == PROTO_GADGET)

            ret = otg_start_gadget(fsm, 0);

        if (ret)

            return ret;

​

        /* start new protocol */

        if (protocol == PROTO_HOST)

            ret = otg_start_host(fsm, 1);

        else if (protocol == PROTO_GADGET)

            ret = otg_start_gadget(fsm, 1);

        if (ret)

            return ret;

​

        fsm->protocol = protocol;

        return 0;

    }

​

    return 0;

}

​

/* Called when leaving a state.  Do state clean up jobs here */

static void otg_leave_state(struct otg_fsm *fsm, enum usb_otg_state old_state)

{

    switch (old_state) {

    case OTG_STATE_B_IDLE:

        otg_del_timer(fsm, B_SE0_SRP);

        fsm->b_se0_srp = 0;

        fsm->adp_sns = 0;

        fsm->adp_prb = 0;

        break;

    case OTG_STATE_B_SRP_INIT:

        fsm->data_pulse = 0;

        fsm->b_srp_done = 0;

        break;

    case OTG_STATE_B_PERIPHERAL:

        if (fsm->otg->gadget)

            fsm->otg->gadget->host_request_flag = 0;

        break;

    case OTG_STATE_B_WAIT_ACON:

        otg_del_timer(fsm, B_ASE0_BRST);

        fsm->b_ase0_brst_tmout = 0;

        break;

    case OTG_STATE_B_HOST:

        break;

    case OTG_STATE_A_IDLE:

        fsm->adp_prb = 0;

        break;

    case OTG_STATE_A_WAIT_VRISE:

        otg_del_timer(fsm, A_WAIT_VRISE);

        fsm->a_wait_vrise_tmout = 0;

        break;

    case OTG_STATE_A_WAIT_BCON:

        otg_del_timer(fsm, A_WAIT_BCON);

        fsm->a_wait_bcon_tmout = 0;