// SPDX-License-Identifier: GPL-2.0+
/*
 * Copyright (C) 2007,2008 Freescale Semiconductor, Inc.
 */

#ifndef __LINUX_USB_OTG_FSM_H
#define __LINUX_USB_OTG_FSM_H

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

#define PROTO_UNDEF     (0)
#define PROTO_HOST      (1)
#define PROTO_GADGET    (2)

#define OTG_STS_SELECTOR        0xF000  /* OTG status selector, according to
                                         * OTG and EH 2.0 Chapter 6.2.3
                                         * Table:6-4
                                         */

#define HOST_REQUEST_FLAG       1       /* Host request flag, according to
                                         * OTG and EH 2.0 Charpter 6.2.3
                                         * Table:6-5
                                         */

#define T_HOST_REQ_POLL         (1500)  /* 1500ms, HNP polling interval */

enum otg_fsm_timer {
        /* Standard OTG timers */
        A_WAIT_VRISE,
        A_WAIT_VFALL,
        A_WAIT_BCON,
        A_AIDL_BDIS,
        B_ASE0_BRST,
        A_BIDL_ADIS,
        B_AIDL_BDIS,

        /* Auxiliary timers */
        B_SE0_SRP,
        B_SRP_FAIL,
        A_WAIT_ENUM,
        B_DATA_PLS,
        B_SSEND_SRP,

        NUM_OTG_FSM_TIMERS,
};

/**
 * struct otg_fsm - OTG state machine according to the OTG spec
 *
 * OTG hardware Inputs
 *
 *      Common inputs for A and B device
 * @id:         TRUE for B-device, FALSE for A-device.
 * @adp_change: TRUE when current ADP measurement (n) value, compared to the
 *              ADP measurement taken at n-2, differs by more than CADP_THR
 * @power_up:   TRUE when the OTG device first powers up its USB system and
 *              ADP measurement taken if ADP capable
 *
 *      A-Device state inputs
 * @a_srp_det:  TRUE if the A-device detects SRP
 * @a_vbus_vld: TRUE when VBUS voltage is in regulation
 * @b_conn:     TRUE if the A-device detects connection from the B-device
 * @a_bus_resume: TRUE when the B-device detects that the A-device is signaling
 *                a resume (K state)
 *      B-Device state inputs
 * @a_bus_suspend: TRUE when the B-device detects that the A-device has put the
 *              bus into suspend
 * @a_conn:     TRUE if the B-device detects a connection from the A-device
 * @b_se0_srp:  TRUE when the line has been at SE0 for more than the minimum
 *              time before generating SRP
 * @b_ssend_srp: TRUE when the VBUS has been below VOTG_SESS_VLD for more than
 *               the minimum time before generating SRP
 * @b_sess_vld: TRUE when the B-device detects that the voltage on VBUS is
 *              above VOTG_SESS_VLD
 * @test_device: TRUE when the B-device switches to B-Host and detects an OTG
 *              test device. This must be set by host/hub driver
 *
 *      Application inputs (A-Device)
 * @a_bus_drop: TRUE when A-device application needs to power down the bus
 * @a_bus_req:  TRUE when A-device application wants to use the bus.
 *              FALSE to suspend the bus
 *
 *      Application inputs (B-Device)
 * @b_bus_req:  TRUE during the time that the Application running on the
 *              B-device wants to use the bus
 *
 *      Auxiliary inputs (OTG v1.3 only. Obsolete now.)
 * @a_sess_vld: TRUE if the A-device detects that VBUS is above VA_SESS_VLD
 * @b_bus_suspend: TRUE when the A-device detects that the B-device has put
 *              the bus into suspend
 * @b_bus_resume: TRUE when the A-device detects that the B-device is signaling
 *               resume on the bus
 *
 * OTG Output status. Read only for users. Updated by OTG FSM helpers defined
 * in this file
 *
 *      Outputs for Both A and B device
 * @drv_vbus:   TRUE when A-device is driving VBUS
 * @loc_conn:   TRUE when the local device has signaled that it is connected
 *              to the bus
 * @loc_sof:    TRUE when the local device is generating activity on the bus
 * @adp_prb:    TRUE when the local device is in the process of doing
 *              ADP probing
 *
 *      Outputs for B-device state
 * @adp_sns:    TRUE when the B-device is in the process of carrying out
 *              ADP sensing
 * @data_pulse: TRUE when the B-device is performing data line pulsing
 *
 * Internal Variables
 *
 * a_set_b_hnp_en: TRUE when the A-device has successfully set the
 *              b_hnp_enable bit in the B-device.
 *                 Unused as OTG fsm uses otg->host->b_hnp_enable instead
 * b_srp_done:  TRUE when the B-device has completed initiating SRP
 * b_hnp_enable: TRUE when the B-device has accepted the
 *              SetFeature(b_hnp_enable) B-device.
 *              Unused as OTG fsm uses otg->gadget->b_hnp_enable instead
 * a_clr_err:   Asserted (by application ?) to clear a_vbus_err due to an
 *              overcurrent condition and causes the A-device to transition
 *              to a_wait_vfall
 */
struct otg_fsm {
        /* Input */
        int id;
        int adp_change;
        int power_up;
        int a_srp_det;
        int a_vbus_vld;
        int b_conn;
        int a_bus_resume;
        int a_bus_suspend;
        int a_conn;
        int b_se0_srp;
        int b_ssend_srp;
        int b_sess_vld;
        int test_device;
        int a_bus_drop;
        int a_bus_req;
        int b_bus_req;

        /* Auxiliary inputs */
        int a_sess_vld;
        int b_bus_resume;
        int b_bus_suspend;

        /* Output */
        int drv_vbus;
        int loc_conn;
        int loc_sof;
        int adp_prb;
        int adp_sns;
        int data_pulse;

        /* Internal variables */
        int a_set_b_hnp_en;
        int b_srp_done;
        int b_hnp_enable;
        int a_clr_err;

        /* Informative variables. All unused as of now */
        int a_bus_drop_inf;
        int a_bus_req_inf;
        int a_clr_err_inf;
        int b_bus_req_inf;
        /* Auxiliary informative variables */
        int a_suspend_req_inf;

        /* Timeout indicator for timers */
        int a_wait_vrise_tmout;
        int a_wait_vfall_tmout;
        int a_wait_bcon_tmout;
        int a_aidl_bdis_tmout;
        int b_ase0_brst_tmout;
        int a_bidl_adis_tmout;

        struct otg_fsm_ops *ops;
        struct usb_otg *otg;

        /* Current usb protocol used: 0:undefine; 1:host; 2:client */
        int protocol;
        struct mutex lock;
        u8 *host_req_flag;
        struct delayed_work hnp_polling_work;
        bool hnp_work_inited;
        bool state_changed;
};

struct otg_fsm_ops {
        void    (*chrg_vbus)(struct otg_fsm *fsm, int on);
        void    (*drv_vbus)(struct otg_fsm *fsm, int on);
        void    (*loc_conn)(struct otg_fsm *fsm, int on);
        void    (*loc_sof)(struct otg_fsm *fsm, int on);
        void    (*start_pulse)(struct otg_fsm *fsm);
        void    (*start_adp_prb)(struct otg_fsm *fsm);
        void    (*start_adp_sns)(struct otg_fsm *fsm);
        void    (*add_timer)(struct otg_fsm *fsm, enum otg_fsm_timer timer);
        void    (*del_timer)(struct otg_fsm *fsm, enum otg_fsm_timer timer);
        int     (*start_host)(struct otg_fsm *fsm, int on);
        int     (*start_gadget)(struct otg_fsm *fsm, int on);
};


static inline int otg_chrg_vbus(struct otg_fsm *fsm, int on)
{
        if (!fsm->ops->chrg_vbus)
                return -EOPNOTSUPP;
        fsm->ops->chrg_vbus(fsm, on);
        return 0;
}

static inline int otg_drv_vbus(struct otg_fsm *fsm, int on)
{
        if (!fsm->ops->drv_vbus)
                return -EOPNOTSUPP;
        if (fsm->drv_vbus != on) {
                fsm->drv_vbus = on;
                fsm->ops->drv_vbus(fsm, on);
        }
        return 0;
}

static inline int otg_loc_conn(struct otg_fsm *fsm, int on)
{
        if (!fsm->ops->loc_conn)
                return -EOPNOTSUPP;
        if (fsm->loc_conn != on) {
                fsm->loc_conn = on;
                fsm->ops->loc_conn(fsm, on);
        }
        return 0;
}

static inline int otg_loc_sof(struct otg_fsm *fsm, int on)
{
        if (!fsm->ops->loc_sof)
                return -EOPNOTSUPP;
        if (fsm->loc_sof != on) {
                fsm->loc_sof = on;
                fsm->ops->loc_sof(fsm, on);
        }
        return 0;
}

static inline int otg_start_pulse(struct otg_fsm *fsm)
{
        if (!fsm->ops->start_pulse)
                return -EOPNOTSUPP;
        if (!fsm->data_pulse) {
                fsm->data_pulse = 1;
                fsm->ops->start_pulse(fsm);
        }
        return 0;
}

static inline int otg_start_adp_prb(struct otg_fsm *fsm)
{
        if (!fsm->ops->start_adp_prb)
                return -EOPNOTSUPP;
        if (!fsm->adp_prb) {
                fsm->adp_sns = 0;
                fsm->adp_prb = 1;
                fsm->ops->start_adp_prb(fsm);
        }
        return 0;
}

static inline int otg_start_adp_sns(struct otg_fsm *fsm)
{
        if (!fsm->ops->start_adp_sns)
                return -EOPNOTSUPP;
        if (!fsm->adp_sns) {
                fsm->adp_sns = 1;
                fsm->ops->start_adp_sns(fsm);
        }
        return 0;
}

static inline int otg_add_timer(struct otg_fsm *fsm, enum otg_fsm_timer timer)
{
        if (!fsm->ops->add_timer)
                return -EOPNOTSUPP;
        fsm->ops->add_timer(fsm, timer);
        return 0;
}

static inline int otg_del_timer(struct otg_fsm *fsm, enum otg_fsm_timer timer)
{
        if (!fsm->ops->del_timer)
                return -EOPNOTSUPP;
        fsm->ops->del_timer(fsm, timer);
        return 0;
}

static inline int otg_start_host(struct otg_fsm *fsm, int on)
{
        if (!fsm->ops->start_host)
                return -EOPNOTSUPP;
        return fsm->ops->start_host(fsm, on);
}

static inline int otg_start_gadget(struct otg_fsm *fsm, int on)
{
        if (!fsm->ops->start_gadget)
                return -EOPNOTSUPP;
        return fsm->ops->start_gadget(fsm, on);
}

int otg_statemachine(struct otg_fsm *fsm);

#endif /* __LINUX_USB_OTG_FSM_H */