// SPDX-License-Identifier: GPL-2.0+
/*
 * Copyright 2015-2017 Google, Inc
 *
 * USB Power Delivery protocol stack.
 */

#include <linux/completion.h>
#include <linux/debugfs.h>
#include <linux/device.h>
#include <linux/hrtimer.h>
#include <linux/jiffies.h>
#include <linux/kernel.h>
#include <linux/kthread.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/power_supply.h>
#include <linux/proc_fs.h>
#include <linux/property.h>
#include <linux/sched/clock.h>
#include <linux/seq_file.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/usb.h>
#include <linux/usb/pd.h>
#include <linux/usb/pd_ado.h>
#include <linux/usb/pd_bdo.h>
#include <linux/usb/pd_ext_sdb.h>
#include <linux/usb/pd_vdo.h>
#include <linux/usb/role.h>
#include <linux/usb/tcpm.h>
#include <linux/usb/typec_altmode.h>

#include <uapi/linux/sched/types.h>

#define FOREACH_STATE(S)                        \
        S(INVALID_STATE),                       \
        S(TOGGLING),                    \
        S(SRC_UNATTACHED),                      \
        S(SRC_ATTACH_WAIT),                     \
        S(SRC_ATTACHED),                        \
        S(SRC_STARTUP),                         \
        S(SRC_SEND_CAPABILITIES),               \
        S(SRC_SEND_CAPABILITIES_TIMEOUT),       \
        S(SRC_NEGOTIATE_CAPABILITIES),          \
        S(SRC_TRANSITION_SUPPLY),               \
        S(SRC_READY),                           \
        S(SRC_WAIT_NEW_CAPABILITIES),           \
                                                \
        S(SNK_UNATTACHED),                      \
        S(SNK_ATTACH_WAIT),                     \
        S(SNK_DEBOUNCED),                       \
        S(SNK_ATTACHED),                        \
        S(SNK_STARTUP),                         \
        S(SNK_DISCOVERY),                       \
        S(SNK_DISCOVERY_DEBOUNCE),              \
        S(SNK_DISCOVERY_DEBOUNCE_DONE),         \
        S(SNK_WAIT_CAPABILITIES),               \
        S(SNK_NEGOTIATE_CAPABILITIES),          \
        S(SNK_NEGOTIATE_PPS_CAPABILITIES),      \
        S(SNK_TRANSITION_SINK),                 \
        S(SNK_TRANSITION_SINK_VBUS),            \
        S(SNK_READY),                           \
                                                \
        S(ACC_UNATTACHED),                      \
        S(DEBUG_ACC_ATTACHED),                  \
        S(AUDIO_ACC_ATTACHED),                  \
        S(AUDIO_ACC_DEBOUNCE),                  \
                                                \
        S(HARD_RESET_SEND),                     \
        S(HARD_RESET_START),                    \
        S(SRC_HARD_RESET_VBUS_OFF),             \
        S(SRC_HARD_RESET_VBUS_ON),              \
        S(SNK_HARD_RESET_SINK_OFF),             \
        S(SNK_HARD_RESET_WAIT_VBUS),            \
        S(SNK_HARD_RESET_SINK_ON),              \
                                                \
        S(SOFT_RESET),                          \
        S(SRC_SOFT_RESET_WAIT_SNK_TX),          \
        S(SNK_SOFT_RESET),                      \
        S(SOFT_RESET_SEND),                     \
                                                \
        S(DR_SWAP_ACCEPT),                      \
        S(DR_SWAP_SEND),                        \
        S(DR_SWAP_SEND_TIMEOUT),                \
        S(DR_SWAP_CANCEL),                      \
        S(DR_SWAP_CHANGE_DR),                   \
                                                \
        S(PR_SWAP_ACCEPT),                      \
        S(PR_SWAP_SEND),                        \
        S(PR_SWAP_SEND_TIMEOUT),                \
        S(PR_SWAP_CANCEL),                      \
        S(PR_SWAP_START),                       \
        S(PR_SWAP_SRC_SNK_TRANSITION_OFF),      \
        S(PR_SWAP_SRC_SNK_SOURCE_OFF),          \
        S(PR_SWAP_SRC_SNK_SOURCE_OFF_CC_DEBOUNCED), \
        S(PR_SWAP_SRC_SNK_SINK_ON),             \
        S(PR_SWAP_SNK_SRC_SINK_OFF),            \
        S(PR_SWAP_SNK_SRC_SOURCE_ON),           \
        S(PR_SWAP_SNK_SRC_SOURCE_ON_VBUS_RAMPED_UP),    \
                                                \
        S(VCONN_SWAP_ACCEPT),                   \
        S(VCONN_SWAP_SEND),                     \
        S(VCONN_SWAP_SEND_TIMEOUT),             \
        S(VCONN_SWAP_CANCEL),                   \
        S(VCONN_SWAP_START),                    \
        S(VCONN_SWAP_WAIT_FOR_VCONN),           \
        S(VCONN_SWAP_TURN_ON_VCONN),            \
        S(VCONN_SWAP_TURN_OFF_VCONN),           \
                                                \
        S(FR_SWAP_SEND),                        \
        S(FR_SWAP_SEND_TIMEOUT),                \
        S(FR_SWAP_SNK_SRC_TRANSITION_TO_OFF),                   \
        S(FR_SWAP_SNK_SRC_NEW_SINK_READY),              \
        S(FR_SWAP_SNK_SRC_SOURCE_VBUS_APPLIED), \
        S(FR_SWAP_CANCEL),                      \
                                                \
        S(SNK_TRY),                             \
        S(SNK_TRY_WAIT),                        \
        S(SNK_TRY_WAIT_DEBOUNCE),               \
        S(SNK_TRY_WAIT_DEBOUNCE_CHECK_VBUS),    \
        S(SRC_TRYWAIT),                         \
        S(SRC_TRYWAIT_DEBOUNCE),                \
        S(SRC_TRYWAIT_UNATTACHED),              \
                                                \
        S(SRC_TRY),                             \
        S(SRC_TRY_WAIT),                        \
        S(SRC_TRY_DEBOUNCE),                    \
        S(SNK_TRYWAIT),                         \
        S(SNK_TRYWAIT_DEBOUNCE),                \
        S(SNK_TRYWAIT_VBUS),                    \
        S(BIST_RX),                             \
                                                \
        S(GET_STATUS_SEND),                     \
        S(GET_STATUS_SEND_TIMEOUT),             \
        S(GET_PPS_STATUS_SEND),                 \
        S(GET_PPS_STATUS_SEND_TIMEOUT),         \
                                                \
        S(GET_SINK_CAP),                        \
        S(GET_SINK_CAP_TIMEOUT),                \
                                                \
        S(ERROR_RECOVERY),                      \
        S(PORT_RESET),                          \
        S(PORT_RESET_WAIT_OFF),                 \
                                                \
        S(AMS_START),                           \
        S(CHUNK_NOT_SUPP)

#define FOREACH_AMS(S)                          \
        S(NONE_AMS),                            \
        S(POWER_NEGOTIATION),                   \
        S(GOTOMIN),                             \
        S(SOFT_RESET_AMS),                      \
        S(HARD_RESET),                          \
        S(CABLE_RESET),                         \
        S(GET_SOURCE_CAPABILITIES),             \
        S(GET_SINK_CAPABILITIES),               \
        S(POWER_ROLE_SWAP),                     \
        S(FAST_ROLE_SWAP),                      \
        S(DATA_ROLE_SWAP),                      \
        S(VCONN_SWAP),                          \
        S(SOURCE_ALERT),                        \
        S(GETTING_SOURCE_EXTENDED_CAPABILITIES),\
        S(GETTING_SOURCE_SINK_STATUS),          \
        S(GETTING_BATTERY_CAPABILITIES),        \
        S(GETTING_BATTERY_STATUS),              \
        S(GETTING_MANUFACTURER_INFORMATION),    \
        S(SECURITY),                            \
        S(FIRMWARE_UPDATE),                     \
        S(DISCOVER_IDENTITY),                   \
        S(SOURCE_STARTUP_CABLE_PLUG_DISCOVER_IDENTITY), \
        S(DISCOVER_SVIDS),                      \
        S(DISCOVER_MODES),                      \
        S(DFP_TO_UFP_ENTER_MODE),               \
        S(DFP_TO_UFP_EXIT_MODE),                \
        S(DFP_TO_CABLE_PLUG_ENTER_MODE),        \
        S(DFP_TO_CABLE_PLUG_EXIT_MODE),         \
        S(ATTENTION),                           \
        S(BIST),                                \
        S(UNSTRUCTURED_VDMS),                   \
        S(STRUCTURED_VDMS),                     \
        S(COUNTRY_INFO),                        \
        S(COUNTRY_CODES)

#define GENERATE_ENUM(e)        e
#define GENERATE_STRING(s)      #s

enum tcpm_state {
        FOREACH_STATE(GENERATE_ENUM)
};

static const char * const tcpm_states[] = {
        FOREACH_STATE(GENERATE_STRING)
};

enum tcpm_ams {
        FOREACH_AMS(GENERATE_ENUM)
};

static const char * const tcpm_ams_str[] = {
        FOREACH_AMS(GENERATE_STRING)
};

enum vdm_states {
        VDM_STATE_ERR_BUSY = -3,
        VDM_STATE_ERR_SEND = -2,
        VDM_STATE_ERR_TMOUT = -1,
        VDM_STATE_DONE = 0,
        /* Anything >0 represents an active state */
        VDM_STATE_READY = 1,
        VDM_STATE_BUSY = 2,
        VDM_STATE_WAIT_RSP_BUSY = 3,
        VDM_STATE_SEND_MESSAGE = 4,
};

enum pd_msg_request {
        PD_MSG_NONE = 0,
        PD_MSG_CTRL_REJECT,
        PD_MSG_CTRL_WAIT,
        PD_MSG_CTRL_NOT_SUPP,
        PD_MSG_DATA_SINK_CAP,
        PD_MSG_DATA_SOURCE_CAP,
};

enum adev_actions {
        ADEV_NONE = 0,
        ADEV_NOTIFY_USB_AND_QUEUE_VDM,
        ADEV_QUEUE_VDM,
        ADEV_QUEUE_VDM_SEND_EXIT_MODE_ON_FAIL,
        ADEV_ATTENTION,
};

/*
 * Initial current capability of the new source when vSafe5V is applied during PD3.0 Fast Role Swap.
 * Based on "Table 6-14 Fixed Supply PDO - Sink" of "USB Power Delivery Specification Revision 3.0,
 * Version 1.2"
 */
enum frs_typec_current {
        FRS_NOT_SUPPORTED,
        FRS_DEFAULT_POWER,
        FRS_5V_1P5A,
        FRS_5V_3A,
};

/* Events from low level driver */

#define TCPM_CC_EVENT           BIT(0)
#define TCPM_VBUS_EVENT         BIT(1)
#define TCPM_RESET_EVENT        BIT(2)
#define TCPM_FRS_EVENT          BIT(3)
#define TCPM_SOURCING_VBUS      BIT(4)

#define LOG_BUFFER_ENTRIES      1024
#define LOG_BUFFER_ENTRY_SIZE   128

/* Alternate mode support */

#define SVID_DISCOVERY_MAX      16
#define ALTMODE_DISCOVERY_MAX   (SVID_DISCOVERY_MAX * MODE_DISCOVERY_MAX)

#define GET_SINK_CAP_RETRY_MS   100
#define SEND_DISCOVER_RETRY_MS  100

struct pd_mode_data {
        int svid_index;         /* current SVID index           */
        int nsvids;
        u16 svids[SVID_DISCOVERY_MAX];
        int altmodes;           /* number of alternate modes    */
        struct typec_altmode_desc altmode_desc[ALTMODE_DISCOVERY_MAX];
};

/*
 * @min_volt: Actual min voltage at the local port
 * @req_min_volt: Requested min voltage to the port partner
 * @max_volt: Actual max voltage at the local port
 * @req_max_volt: Requested max voltage to the port partner
 * @max_curr: Actual max current at the local port
 * @req_max_curr: Requested max current of the port partner
 * @req_out_volt: Requested output voltage to the port partner
 * @req_op_curr: Requested operating current to the port partner
 * @supported: Parter has atleast one APDO hence supports PPS
 * @active: PPS mode is active
 */
struct pd_pps_data {
        u32 min_volt;
        u32 req_min_volt;
        u32 max_volt;
        u32 req_max_volt;
        u32 max_curr;
        u32 req_max_curr;
        u32 req_out_volt;
        u32 req_op_curr;
        bool supported;
        bool active;
};

struct tcpm_port {
        struct device *dev;

        struct mutex lock;              /* tcpm state machine lock */
        struct kthread_worker *wq;

        struct typec_capability typec_caps;
        struct typec_port *typec_port;

        struct tcpc_dev *tcpc;
        struct usb_role_switch *role_sw;

        enum typec_role vconn_role;
        enum typec_role pwr_role;
        enum typec_data_role data_role;
        enum typec_pwr_opmode pwr_opmode;

        struct usb_pd_identity partner_ident;
        struct typec_partner_desc partner_desc;
        struct typec_partner *partner;

        enum typec_cc_status cc_req;

        enum typec_cc_status cc1;
        enum typec_cc_status cc2;
        enum typec_cc_polarity polarity;

        bool attached;
        bool connected;
        enum typec_port_type port_type;

        /*
         * Set to true when vbus is greater than VSAFE5V min.
         * Set to false when vbus falls below vSinkDisconnect max threshold.
         */
        bool vbus_present;

        /*
         * Set to true when vbus is less than VSAFE0V max.
         * Set to false when vbus is greater than VSAFE0V max.
         */
        bool vbus_vsafe0v;

        bool vbus_never_low;
        bool vbus_source;
        bool vbus_charge;

        /* Set to true when Discover_Identity Command is expected to be sent in Ready states. */
        bool send_discover;
        bool op_vsafe5v;

        int try_role;
        int try_snk_count;
        int try_src_count;

        enum pd_msg_request queued_message;

        enum tcpm_state enter_state;
        enum tcpm_state prev_state;
        enum tcpm_state state;
        enum tcpm_state delayed_state;
        ktime_t delayed_runtime;
        unsigned long delay_ms;

        spinlock_t pd_event_lock;
        u32 pd_events;

        struct kthread_work event_work;
        struct hrtimer state_machine_timer;
        struct kthread_work state_machine;
        struct hrtimer vdm_state_machine_timer;
        struct kthread_work vdm_state_machine;
        struct hrtimer enable_frs_timer;
        struct kthread_work enable_frs;
        struct hrtimer send_discover_timer;
        struct kthread_work send_discover_work;
        bool state_machine_running;
        /* Set to true when VDM State Machine has following actions. */
        bool vdm_sm_running;

        struct completion tx_complete;
        enum tcpm_transmit_status tx_status;

        struct mutex swap_lock;         /* swap command lock */
        bool swap_pending;
        bool non_pd_role_swap;
        struct completion swap_complete;
        int swap_status;

        unsigned int negotiated_rev;
        unsigned int message_id;
        unsigned int caps_count;
        unsigned int hard_reset_count;
        bool pd_capable;
        bool explicit_contract;
        unsigned int rx_msgid;

        /* Partner capabilities/requests */
        u32 sink_request;
        u32 source_caps[PDO_MAX_OBJECTS];
        unsigned int nr_source_caps;
        u32 sink_caps[PDO_MAX_OBJECTS];
        unsigned int nr_sink_caps;

        /* Local capabilities */
        u32 src_pdo[PDO_MAX_OBJECTS];
        unsigned int nr_src_pdo;
        u32 snk_pdo[PDO_MAX_OBJECTS];
        unsigned int nr_snk_pdo;
        u32 snk_vdo_v1[VDO_MAX_OBJECTS];
        unsigned int nr_snk_vdo_v1;
        u32 snk_vdo[VDO_MAX_OBJECTS];
        unsigned int nr_snk_vdo;

        unsigned int operating_snk_mw;
        bool update_sink_caps;

        /* Requested current / voltage to the port partner */
        u32 req_current_limit;
        u32 req_supply_voltage;
        /* Actual current / voltage limit of the local port */
        u32 current_limit;
        u32 supply_voltage;

        /* Used to export TA voltage and current */
        struct power_supply *psy;
        struct power_supply_desc psy_desc;
        enum power_supply_usb_type usb_type;

        u32 bist_request;

        /* PD state for Vendor Defined Messages */
        enum vdm_states vdm_state;
        u32 vdm_retries;
        /* next Vendor Defined Message to send */
        u32 vdo_data[VDO_MAX_SIZE];
        u8 vdo_count;
        /* VDO to retry if UFP responder replied busy */
        u32 vdo_retry;

        /* PPS */
        struct pd_pps_data pps_data;
        struct completion pps_complete;
        bool pps_pending;
        int pps_status;

        /* Alternate mode data */
        struct pd_mode_data mode_data;
        struct typec_altmode *partner_altmode[ALTMODE_DISCOVERY_MAX];
        struct typec_altmode *port_altmode[ALTMODE_DISCOVERY_MAX];

        /* Deadline in jiffies to exit src_try_wait state */
        unsigned long max_wait;

        /* port belongs to a self powered device */
        bool self_powered;

        /* Sink FRS */
        enum frs_typec_current new_source_frs_current;

        /* Sink caps have been queried */
        bool sink_cap_done;

        /* Collision Avoidance and Atomic Message Sequence */
        enum tcpm_state upcoming_state;
        enum tcpm_ams ams;
        enum tcpm_ams next_ams;
        bool in_ams;

        /* Auto vbus discharge status */
        bool auto_vbus_discharge_enabled;

        /*
         * When set, port requests PD_P_SNK_STDBY_MW upon entering SNK_DISCOVERY and
         * the actual currrent limit after RX of PD_CTRL_PSRDY for PD link,
         * SNK_READY for non-pd link.
         */
        bool slow_charger_loop;
#ifdef CONFIG_DEBUG_FS
        struct dentry *dentry;
        struct mutex logbuffer_lock;    /* log buffer access lock */
        int logbuffer_head;
        int logbuffer_tail;
        u8 *logbuffer[LOG_BUFFER_ENTRIES];
#endif
};

struct pd_rx_event {
        struct kthread_work work;
        struct tcpm_port *port;
        struct pd_message msg;
};

static const char * const pd_rev[] = {
        [PD_REV10]              = "rev1",
        [PD_REV20]              = "rev2",
        [PD_REV30]              = "rev3",
};

#define tcpm_cc_is_sink(cc) \
        ((cc) == TYPEC_CC_RP_DEF || (cc) == TYPEC_CC_RP_1_5 || \
         (cc) == TYPEC_CC_RP_3_0)

#define tcpm_port_is_sink(port) \
        ((tcpm_cc_is_sink((port)->cc1) && !tcpm_cc_is_sink((port)->cc2)) || \
         (tcpm_cc_is_sink((port)->cc2) && !tcpm_cc_is_sink((port)->cc1)))

#define tcpm_cc_is_source(cc) ((cc) == TYPEC_CC_RD)
#define tcpm_cc_is_audio(cc) ((cc) == TYPEC_CC_RA)
#define tcpm_cc_is_open(cc) ((cc) == TYPEC_CC_OPEN)

#define tcpm_port_is_source(port) \
        ((tcpm_cc_is_source((port)->cc1) && \
         !tcpm_cc_is_source((port)->cc2)) || \
         (tcpm_cc_is_source((port)->cc2) && \
          !tcpm_cc_is_source((port)->cc1)))

#define tcpm_port_is_debug(port) \
        (tcpm_cc_is_source((port)->cc1) && tcpm_cc_is_source((port)->cc2))

#define tcpm_port_is_audio(port) \
        (tcpm_cc_is_audio((port)->cc1) && tcpm_cc_is_audio((port)->cc2))

#define tcpm_port_is_audio_detached(port) \
        ((tcpm_cc_is_audio((port)->cc1) && tcpm_cc_is_open((port)->cc2)) || \
         (tcpm_cc_is_audio((port)->cc2) && tcpm_cc_is_open((port)->cc1)))

#define tcpm_try_snk(port) \
        ((port)->try_snk_count == 0 && (port)->try_role == TYPEC_SINK && \
        (port)->port_type == TYPEC_PORT_DRP)

#define tcpm_try_src(port) \
        ((port)->try_src_count == 0 && (port)->try_role == TYPEC_SOURCE && \
        (port)->port_type == TYPEC_PORT_DRP)

#define tcpm_data_role_for_source(port) \
        ((port)->typec_caps.data == TYPEC_PORT_UFP ? \
        TYPEC_DEVICE : TYPEC_HOST)

#define tcpm_data_role_for_sink(port) \
        ((port)->typec_caps.data == TYPEC_PORT_DFP ? \
        TYPEC_HOST : TYPEC_DEVICE)

#define tcpm_sink_tx_ok(port) \
        (tcpm_port_is_sink(port) && \
        ((port)->cc1 == TYPEC_CC_RP_3_0 || (port)->cc2 == TYPEC_CC_RP_3_0))

#define tcpm_wait_for_discharge(port) \
        (((port)->auto_vbus_discharge_enabled && !(port)->vbus_vsafe0v) ? PD_T_SAFE_0V : 0)

static enum tcpm_state tcpm_default_state(struct tcpm_port *port)
{
        if (port->port_type == TYPEC_PORT_DRP) {
                if (port->try_role == TYPEC_SINK)
                        return SNK_UNATTACHED;
                else if (port->try_role == TYPEC_SOURCE)
                        return SRC_UNATTACHED;
                /* Fall through to return SRC_UNATTACHED */
        } else if (port->port_type == TYPEC_PORT_SNK) {
                return SNK_UNATTACHED;
        }
        return SRC_UNATTACHED;
}

static bool tcpm_port_is_disconnected(struct tcpm_port *port)
{
        return (!port->attached && port->cc1 == TYPEC_CC_OPEN &&
                port->cc2 == TYPEC_CC_OPEN) ||
               (port->attached && ((port->polarity == TYPEC_POLARITY_CC1 &&
                                    port->cc1 == TYPEC_CC_OPEN) ||
                                   (port->polarity == TYPEC_POLARITY_CC2 &&
                                    port->cc2 == TYPEC_CC_OPEN)));
}

/*
 * Logging
 */

#ifdef CONFIG_DEBUG_FS

static bool tcpm_log_full(struct tcpm_port *port)
{
        return port->logbuffer_tail ==
                (port->logbuffer_head + 1) % LOG_BUFFER_ENTRIES;
}

__printf(2, 0)
static void _tcpm_log(struct tcpm_port *port, const char *fmt, va_list args)
{
        char tmpbuffer[LOG_BUFFER_ENTRY_SIZE];
        u64 ts_nsec = local_clock();
        unsigned long rem_nsec;

        mutex_lock(&port->logbuffer_lock);
        if (!port->logbuffer[port->logbuffer_head]) {
                port->logbuffer[port->logbuffer_head] =
                                kzalloc(LOG_BUFFER_ENTRY_SIZE, GFP_KERNEL);
                if (!port->logbuffer[port->logbuffer_head]) {
                        mutex_unlock(&port->logbuffer_lock);
                        return;
                }
        }

        vsnprintf(tmpbuffer, sizeof(tmpbuffer), fmt, args);

        if (tcpm_log_full(port)) {
                port->logbuffer_head = max(port->logbuffer_head - 1, 0);
                strcpy(tmpbuffer, "overflow");
        }

        if (port->logbuffer_head < 0 ||
            port->logbuffer_head >= LOG_BUFFER_ENTRIES) {
                dev_warn(port->dev,
                         "Bad log buffer index %d\n", port->logbuffer_head);
                goto abort;
        }

        if (!port->logbuffer[port->logbuffer_head]) {
                dev_warn(port->dev,
                         "Log buffer index %d is NULL\n", port->logbuffer_head);
                goto abort;
        }

        rem_nsec = do_div(ts_nsec, 1000000000);
        scnprintf(port->logbuffer[port->logbuffer_head],
                  LOG_BUFFER_ENTRY_SIZE, "[%5lu.%06lu] %s",
                  (unsigned long)ts_nsec, rem_nsec / 1000,
                  tmpbuffer);
        port->logbuffer_head = (port->logbuffer_head + 1) % LOG_BUFFER_ENTRIES;

abort:
        mutex_unlock(&port->logbuffer_lock);
}

__printf(2, 3)
static void tcpm_log(struct tcpm_port *port, const char *fmt, ...)
{
        va_list args;

        /* Do not log while disconnected and unattached */
        if (tcpm_port_is_disconnected(port) &&
            (port->state == SRC_UNATTACHED || port->state == SNK_UNATTACHED ||
             port->state == TOGGLING))
                return;

        va_start(args, fmt);
        _tcpm_log(port, fmt, args);
        va_end(args);
}

__printf(2, 3)
static void tcpm_log_force(struct tcpm_port *port, const char *fmt, ...)
{
        va_list args;

        va_start(args, fmt);
        _tcpm_log(port, fmt, args);
        va_end(args);
}

static void tcpm_log_source_caps(struct tcpm_port *port)
{
        int i;

        for (i = 0; i < port->nr_source_caps; i++) {
                u32 pdo = port->source_caps[i];
                enum pd_pdo_type type = pdo_type(pdo);
                char msg[64];

                switch (type) {
                case PDO_TYPE_FIXED:
                        scnprintf(msg, sizeof(msg),
                                  "%u mV, %u mA [%s%s%s%s%s%s]",
                                  pdo_fixed_voltage(pdo),
                                  pdo_max_current(pdo),
                                  (pdo & PDO_FIXED_DUAL_ROLE) ?
                                                        "R" : "",
                                  (pdo & PDO_FIXED_SUSPEND) ?
                                                        "S" : "",
                                  (pdo & PDO_FIXED_HIGHER_CAP) ?
                                                        "H" : "",
                                  (pdo & PDO_FIXED_USB_COMM) ?
                                                        "U" : "",
                                  (pdo & PDO_FIXED_DATA_SWAP) ?
                                                        "D" : "",
                                  (pdo & PDO_FIXED_EXTPOWER) ?
                                                        "E" : "");
                        break;
                case PDO_TYPE_VAR:
                        scnprintf(msg, sizeof(msg),
                                  "%u-%u mV, %u mA",
                                  pdo_min_voltage(pdo),
                                  pdo_max_voltage(pdo),
                                  pdo_max_current(pdo));
                        break;
                case PDO_TYPE_BATT:
                        scnprintf(msg, sizeof(msg),
                                  "%u-%u mV, %u mW",
                                  pdo_min_voltage(pdo),
                                  pdo_max_voltage(pdo),
                                  pdo_max_power(pdo));
                        break;
                case PDO_TYPE_APDO:
                        if (pdo_apdo_type(pdo) == APDO_TYPE_PPS)
                                scnprintf(msg, sizeof(msg),
                                          "%u-%u mV, %u mA",
                                          pdo_pps_apdo_min_voltage(pdo),
                                          pdo_pps_apdo_max_voltage(pdo),
                                          pdo_pps_apdo_max_current(pdo));
                        else
                                strcpy(msg, "undefined APDO");
                        break;
                default:
                        strcpy(msg, "undefined");
                        break;
                }
                tcpm_log(port, " PDO %d: type %d, %s",
                         i, type, msg);
        }
}

static int tcpm_debug_show(struct seq_file *s, void *v)
{
        struct tcpm_port *port = (struct tcpm_port *)s->private;
        int tail;

        mutex_lock(&port->logbuffer_lock);
        tail = port->logbuffer_tail;
        while (tail != port->logbuffer_head) {
                seq_printf(s, "%s\n", port->logbuffer[tail]);
                tail = (tail + 1) % LOG_BUFFER_ENTRIES;
        }
        if (!seq_has_overflowed(s))
                port->logbuffer_tail = tail;
        mutex_unlock(&port->logbuffer_lock);

        return 0;
}
DEFINE_SHOW_ATTRIBUTE(tcpm_debug);

static void tcpm_debugfs_init(struct tcpm_port *port)
{
        char name[NAME_MAX];

        mutex_init(&port->logbuffer_lock);
        snprintf(name, NAME_MAX, "tcpm-%s", dev_name(port->dev));
        port->dentry = debugfs_create_dir(name, usb_debug_root);
        debugfs_create_file("log", S_IFREG | 0444, port->dentry, port,
                            &tcpm_debug_fops);
}

static void tcpm_debugfs_exit(struct tcpm_port *port)
{
        int i;

        mutex_lock(&port->logbuffer_lock);
        for (i = 0; i < LOG_BUFFER_ENTRIES; i++) {
                kfree(port->logbuffer[i]);
                port->logbuffer[i] = NULL;
        }
        mutex_unlock(&port->logbuffer_lock);

        debugfs_remove(port->dentry);
}

#else

__printf(2, 3)
static void tcpm_log(const struct tcpm_port *port, const char *fmt, ...) { }
__printf(2, 3)
static void tcpm_log_force(struct tcpm_port *port, const char *fmt, ...) { }
static void tcpm_log_source_caps(struct tcpm_port *port) { }
static void tcpm_debugfs_init(const struct tcpm_port *port) { }
static void tcpm_debugfs_exit(const struct tcpm_port *port) { }

#endif

static void tcpm_set_cc(struct tcpm_port *port, enum typec_cc_status cc)
{
        tcpm_log(port, "cc:=%d", cc);
        port->cc_req = cc;
        port->tcpc->set_cc(port->tcpc, cc);
}

static int tcpm_enable_auto_vbus_discharge(struct tcpm_port *port, bool enable)
{
        int ret = 0;

        if (port->tcpc->enable_auto_vbus_discharge) {
                ret = port->tcpc->enable_auto_vbus_discharge(port->tcpc, enable);
                tcpm_log_force(port, "%s vbus discharge ret:%d", enable ? "enable" : "disable",
                               ret);
                if (!ret)
                        port->auto_vbus_discharge_enabled = enable;
        }

        return ret;
}

static void tcpm_apply_rc(struct tcpm_port *port)
{
        /*
         * TCPCI: Move to APPLY_RC state to prevent disconnect during PR_SWAP
         * when Vbus auto discharge on disconnect is enabled.
         */
        if (port->tcpc->enable_auto_vbus_discharge && port->tcpc->apply_rc) {
                tcpm_log(port, "Apply_RC");
                port->tcpc->apply_rc(port->tcpc, port->cc_req, port->polarity);
                tcpm_enable_auto_vbus_discharge(port, false);
        }
}

/*
 * Determine RP value to set based on maximum current supported
 * by a port if configured as source.
 * Returns CC value to report to link partner.
 */
static enum typec_cc_status tcpm_rp_cc(struct tcpm_port *port)
{
        const u32 *src_pdo = port->src_pdo;
        int nr_pdo = port->nr_src_pdo;
        int i;

        /*
         * Search for first entry with matching voltage.
         * It should report the maximum supported current.
         */
        for (i = 0; i < nr_pdo; i++) {
                const u32 pdo = src_pdo[i];

                if (pdo_type(pdo) == PDO_TYPE_FIXED &&
                    pdo_fixed_voltage(pdo) == 5000) {
                        unsigned int curr = pdo_max_current(pdo);

                        if (curr >= 3000)
                                return TYPEC_CC_RP_3_0;
                        else if (curr >= 1500)
                                return TYPEC_CC_RP_1_5;
                        return TYPEC_CC_RP_DEF;
                }
        }

        return TYPEC_CC_RP_DEF;
}

static void tcpm_ams_finish(struct tcpm_port *port)
{
        tcpm_log(port, "AMS %s finished", tcpm_ams_str[port->ams]);

        if (port->pd_capable && port->pwr_role == TYPEC_SOURCE) {
                if (port->negotiated_rev >= PD_REV30)
                        tcpm_set_cc(port, SINK_TX_OK);
                else
                        tcpm_set_cc(port, SINK_TX_NG);
        } else if (port->pwr_role == TYPEC_SOURCE) {
                tcpm_set_cc(port, tcpm_rp_cc(port));
        }

        port->in_ams = false;
        port->ams = NONE_AMS;
}

static int tcpm_pd_transmit(struct tcpm_port *port,
                            enum tcpm_transmit_type type,
                            const struct pd_message *msg)
{
        unsigned long timeout;
        int ret;

        if (msg)
                tcpm_log(port, "PD TX, header: %#x", le16_to_cpu(msg->header));
        else
                tcpm_log(port, "PD TX, type: %#x", type);

        reinit_completion(&port->tx_complete);
        ret = port->tcpc->pd_transmit(port->tcpc, type, msg, port->negotiated_rev);
        if (ret < 0)
                return ret;

        mutex_unlock(&port->lock);
        timeout = wait_for_completion_timeout(&port->tx_complete,
                                msecs_to_jiffies(PD_T_TCPC_TX_TIMEOUT));
        mutex_lock(&port->lock);
        if (!timeout)
                return -ETIMEDOUT;

        switch (port->tx_status) {
        case TCPC_TX_SUCCESS:
                port->message_id = (port->message_id + 1) & PD_HEADER_ID_MASK;
                /*
                 * USB PD rev 2.0, 8.3.2.2.1:
                 * USB PD rev 3.0, 8.3.2.1.3:
                 * "... Note that every AMS is Interruptible until the first
                 * Message in the sequence has been successfully sent (GoodCRC
                 * Message received)."
                 */
                if (port->ams != NONE_AMS)
                        port->in_ams = true;
                break;
        case TCPC_TX_DISCARDED:
                ret = -EAGAIN;
                break;
        case TCPC_TX_FAILED:
        default:
                ret = -EIO;
                break;
        }

        /* Some AMS don't expect responses. Finish them here. */
        if (port->ams == ATTENTION || port->ams == SOURCE_ALERT)
                tcpm_ams_finish(port);

        return ret;
}

void tcpm_pd_transmit_complete(struct tcpm_port *port,
                               enum tcpm_transmit_status status)
{
        tcpm_log(port, "PD TX complete, status: %u", status);
        port->tx_status = status;
        complete(&port->tx_complete);
}
EXPORT_SYMBOL_GPL(tcpm_pd_transmit_complete);

static int tcpm_mux_set(struct tcpm_port *port, int state,
                        enum usb_role usb_role,
                        enum typec_orientation orientation)
{
        int ret;

        tcpm_log(port, "Requesting mux state %d, usb-role %d, orientation %d",
                 state, usb_role, orientation);

        ret = typec_set_orientation(port->typec_port, orientation);
        if (ret)
                return ret;

        if (port->role_sw) {
                ret = usb_role_switch_set_role(port->role_sw, usb_role);
                if (ret)
                        return ret;
        }

        return typec_set_mode(port->typec_port, state);
}

static int tcpm_set_polarity(struct tcpm_port *port,
                             enum typec_cc_polarity polarity)
{
        int ret;

        tcpm_log(port, "polarity %d", polarity);

        ret = port->tcpc->set_polarity(port->tcpc, polarity);
        if (ret < 0)
                return ret;

        port->polarity = polarity;

        return 0;
}

static int tcpm_set_vconn(struct tcpm_port *port, bool enable)
{
        int ret;

        tcpm_log(port, "vconn:=%d", enable);

        ret = port->tcpc->set_vconn(port->tcpc, enable);
        if (!ret) {
                port->vconn_role = enable ? TYPEC_SOURCE : TYPEC_SINK;
                typec_set_vconn_role(port->typec_port, port->vconn_role);
        }

        return ret;
}

static u32 tcpm_get_current_limit(struct tcpm_port *port)
{
        enum typec_cc_status cc;
        u32 limit;

        cc = port->polarity ? port->cc2 : port->cc1;
        switch (cc) {
        case TYPEC_CC_RP_1_5:
                limit = 1500;
                break;
        case TYPEC_CC_RP_3_0:
                limit = 3000;
                break;
        case TYPEC_CC_RP_DEF:
        default:
                if (port->tcpc->get_current_limit)
                        limit = port->tcpc->get_current_limit(port->tcpc);
                else
                        limit = 0;
                break;
        }

        return limit;
}

static int tcpm_set_current_limit(struct tcpm_port *port, u32 max_ma, u32 mv)
{

        int ret = -EOPNOTSUPP;

        tcpm_log(port, "Setting voltage/current limit %u mV %u mA", mv, max_ma);

        port->supply_voltage = mv;
        port->current_limit = max_ma;
        power_supply_changed(port->psy);

        if (port->tcpc->set_current_limit)
                ret = port->tcpc->set_current_limit(port->tcpc, max_ma, mv);

        return ret;
}

static int tcpm_set_attached_state(struct tcpm_port *port, bool attached)
{
        return port->tcpc->set_roles(port->tcpc, attached, port->pwr_role,
                                     port->data_role);
}

static int tcpm_set_roles(struct tcpm_port *port, bool attached,
                          enum typec_role role, enum typec_data_role data)
{
        enum typec_orientation orientation;
        enum usb_role usb_role;
        int ret;

        if (port->polarity == TYPEC_POLARITY_CC1)
                orientation = TYPEC_ORIENTATION_NORMAL;
        else
                orientation = TYPEC_ORIENTATION_REVERSE;

        if (port->typec_caps.data == TYPEC_PORT_DRD) {
                if (data == TYPEC_HOST)
                        usb_role = USB_ROLE_HOST;
                else
                        usb_role = USB_ROLE_DEVICE;
        } else if (port->typec_caps.data == TYPEC_PORT_DFP) {
                if (data == TYPEC_HOST) {
                        if (role == TYPEC_SOURCE)
                                usb_role = USB_ROLE_HOST;
                        else
                                usb_role = USB_ROLE_NONE;
                } else {
                        return -ENOTSUPP;
                }
        } else {
                if (data == TYPEC_DEVICE) {
                        if (role == TYPEC_SINK)
                                usb_role = USB_ROLE_DEVICE;
                        else
                                usb_role = USB_ROLE_NONE;
                } else {
                        return -ENOTSUPP;
                }
        }

        ret = tcpm_mux_set(port, TYPEC_STATE_USB, usb_role, orientation);
        if (ret < 0)
                return ret;

        ret = port->tcpc->set_roles(port->tcpc, attached, role, data);
        if (ret < 0)
                return ret;

        port->pwr_role = role;
        port->data_role = data;
        typec_set_data_role(port->typec_port, data);
        typec_set_pwr_role(port->typec_port, role);

        return 0;
}

static int tcpm_set_pwr_role(struct tcpm_port *port, enum typec_role role)
{
        int ret;

        ret = port->tcpc->set_roles(port->tcpc, true, role,
                                    port->data_role);
        if (ret < 0)
                return ret;

        port->pwr_role = role;
        typec_set_pwr_role(port->typec_port, role);

        return 0;
}

/*
 * Transform the PDO to be compliant to PD rev2.0.
 * Return 0 if the PDO type is not defined in PD rev2.0.
 * Otherwise, return the converted PDO.
 */
static u32 tcpm_forge_legacy_pdo(struct tcpm_port *port, u32 pdo, enum typec_role role)
{
        switch (pdo_type(pdo)) {
        case PDO_TYPE_FIXED:
                if (role == TYPEC_SINK)
                        return pdo & ~PDO_FIXED_FRS_CURR_MASK;
                else
                        return pdo & ~PDO_FIXED_UNCHUNK_EXT;
        case PDO_TYPE_VAR:
        case PDO_TYPE_BATT:
                return pdo;
        case PDO_TYPE_APDO:
        default:
                return 0;
        }
}

static int tcpm_pd_send_source_caps(struct tcpm_port *port)
{
        struct pd_message msg;
        u32 pdo;
        unsigned int i, nr_pdo = 0;

        memset(&msg, 0, sizeof(msg));

        for (i = 0; i < port->nr_src_pdo; i++) {
                if (port->negotiated_rev >= PD_REV30) {
                        msg.payload[nr_pdo++] = cpu_to_le32(port->src_pdo[i]);
                } else {
                        pdo = tcpm_forge_legacy_pdo(port, port->src_pdo[i], TYPEC_SOURCE);
                        if (pdo)
                                msg.payload[nr_pdo++] = cpu_to_le32(pdo);
                }
        }

        if (!nr_pdo) {
                /* No source capabilities defined, sink only */
                msg.header = PD_HEADER_LE(PD_CTRL_REJECT,
                                          port->pwr_role,
                                          port->data_role,
                                          port->negotiated_rev,
                                          port->message_id, 0);
        } else {
                msg.header = PD_HEADER_LE(PD_DATA_SOURCE_CAP,
                                          port->pwr_role,
                                          port->data_role,
                                          port->negotiated_rev,
                                          port->message_id,
                                          nr_pdo);
        }

        return tcpm_pd_transmit(port, TCPC_TX_SOP, &msg);
}

static int tcpm_pd_send_sink_caps(struct tcpm_port *port)
{
        struct pd_message msg;
        u32 pdo;
        unsigned int i, nr_pdo = 0;

        memset(&msg, 0, sizeof(msg));

        for (i = 0; i < port->nr_snk_pdo; i++) {
                if (port->negotiated_rev >= PD_REV30) {
                        msg.payload[nr_pdo++] = cpu_to_le32(port->snk_pdo[i]);
                } else {
                        pdo = tcpm_forge_legacy_pdo(port, port->snk_pdo[i], TYPEC_SINK);
                        if (pdo)
                                msg.payload[nr_pdo++] = cpu_to_le32(pdo);
                }
        }

        if (!nr_pdo) {
                /* No sink capabilities defined, source only */
                msg.header = PD_HEADER_LE(PD_CTRL_REJECT,
                                          port->pwr_role,
                                          port->data_role,
                                          port->negotiated_rev,
                                          port->message_id, 0);
        } else {
                msg.header = PD_HEADER_LE(PD_DATA_SINK_CAP,
                                          port->pwr_role,
                                          port->data_role,
                                          port->negotiated_rev,
                                          port->message_id,
                                          nr_pdo);
        }

        return tcpm_pd_transmit(port, TCPC_TX_SOP, &msg);
}

static void mod_tcpm_delayed_work(struct tcpm_port *port, unsigned int delay_ms)
{
        if (delay_ms) {
                hrtimer_start(&port->state_machine_timer, ms_to_ktime(delay_ms), HRTIMER_MODE_REL);
        } else {
                hrtimer_cancel(&port->state_machine_timer);
                kthread_queue_work(port->wq, &port->state_machine);
        }
}

static void mod_vdm_delayed_work(struct tcpm_port *port, unsigned int delay_ms)
{
        if (delay_ms) {
                hrtimer_start(&port->vdm_state_machine_timer, ms_to_ktime(delay_ms),
                              HRTIMER_MODE_REL);
        } else {
                hrtimer_cancel(&port->vdm_state_machine_timer);
                kthread_queue_work(port->wq, &port->vdm_state_machine);
        }
}

static void mod_enable_frs_delayed_work(struct tcpm_port *port, unsigned int delay_ms)
{
        if (delay_ms) {
                hrtimer_start(&port->enable_frs_timer, ms_to_ktime(delay_ms), HRTIMER_MODE_REL);
        } else {
                hrtimer_cancel(&port->enable_frs_timer);
                kthread_queue_work(port->wq, &port->enable_frs);
        }
}

static void mod_send_discover_delayed_work(struct tcpm_port *port, unsigned int delay_ms)
{
        if (delay_ms) {
                hrtimer_start(&port->send_discover_timer, ms_to_ktime(delay_ms), HRTIMER_MODE_REL);
        } else {
                hrtimer_cancel(&port->send_discover_timer);
                kthread_queue_work(port->wq, &port->send_discover_work);
        }
}

static void tcpm_set_state(struct tcpm_port *port, enum tcpm_state state,
                           unsigned int delay_ms)
{
        if (delay_ms) {
                tcpm_log(port, "pending state change %s -> %s @ %u ms [%s %s]",
                         tcpm_states[port->state], tcpm_states[state], delay_ms,
                         pd_rev[port->negotiated_rev], tcpm_ams_str[port->ams]);
                port->delayed_state = state;
                mod_tcpm_delayed_work(port, delay_ms);
                port->delayed_runtime = ktime_add(ktime_get(), ms_to_ktime(delay_ms));
                port->delay_ms = delay_ms;
        } else {
                tcpm_log(port, "state change %s -> %s [%s %s]",
                         tcpm_states[port->state], tcpm_states[state],
                         pd_rev[port->negotiated_rev], tcpm_ams_str[port->ams]);
                port->delayed_state = INVALID_STATE;
                port->prev_state = port->state;
                port->state = state;
                /*
                 * Don't re-queue the state machine work item if we're currently
                 * in the state machine and we're immediately changing states.
                 * tcpm_state_machine_work() will continue running the state
                 * machine.
                 */
                if (!port->state_machine_running)
                        mod_tcpm_delayed_work(port, 0);
        }
}

static void tcpm_set_state_cond(struct tcpm_port *port, enum tcpm_state state,
                                unsigned int delay_ms)
{
        if (port->enter_state == port->state)
                tcpm_set_state(port, state, delay_ms);
        else
                tcpm_log(port,
                         "skipped %sstate change %s -> %s [%u ms], context state %s [%s %s]",
                         delay_ms ? "delayed " : "",
                         tcpm_states[port->state], tcpm_states[state],
                         delay_ms, tcpm_states[port->enter_state],
                         pd_rev[port->negotiated_rev], tcpm_ams_str[port->ams]);
}

static void tcpm_queue_message(struct tcpm_port *port,
                               enum pd_msg_request message)
{
        port->queued_message = message;
        mod_tcpm_delayed_work(port, 0);
}

static bool tcpm_vdm_ams(struct tcpm_port *port)
{
        switch (port->ams) {
        case DISCOVER_IDENTITY:
        case SOURCE_STARTUP_CABLE_PLUG_DISCOVER_IDENTITY:
        case DISCOVER_SVIDS:
        case DISCOVER_MODES:
        case DFP_TO_UFP_ENTER_MODE:
        case DFP_TO_UFP_EXIT_MODE:
        case DFP_TO_CABLE_PLUG_ENTER_MODE:
        case DFP_TO_CABLE_PLUG_EXIT_MODE:
        case ATTENTION:
        case UNSTRUCTURED_VDMS:
        case STRUCTURED_VDMS:
                break;
        default:
                return false;
        }

        return true;
}

static bool tcpm_ams_interruptible(struct tcpm_port *port)
{
        switch (port->ams) {
        /* Interruptible AMS */
        case NONE_AMS:
        case SECURITY:
        case FIRMWARE_UPDATE:
        case DISCOVER_IDENTITY:
        case SOURCE_STARTUP_CABLE_PLUG_DISCOVER_IDENTITY:
        case DISCOVER_SVIDS:
        case DISCOVER_MODES:
        case DFP_TO_UFP_ENTER_MODE:
        case DFP_TO_UFP_EXIT_MODE:
        case DFP_TO_CABLE_PLUG_ENTER_MODE:
        case DFP_TO_CABLE_PLUG_EXIT_MODE:
        case UNSTRUCTURED_VDMS:
        case STRUCTURED_VDMS:
        case COUNTRY_INFO:
        case COUNTRY_CODES:
                break;
        /* Non-Interruptible AMS */
        default:
                if (port->in_ams)
                        return false;
                break;
        }

        return true;
}

static int tcpm_ams_start(struct tcpm_port *port, enum tcpm_ams ams)
{
        int ret = 0;

        tcpm_log(port, "AMS %s start", tcpm_ams_str[ams]);

        if (!tcpm_ams_interruptible(port) &&
            !(ams == HARD_RESET || ams == SOFT_RESET_AMS)) {
                port->upcoming_state = INVALID_STATE;
                tcpm_log(port, "AMS %s not interruptible, aborting",
                         tcpm_ams_str[port->ams]);
                return -EAGAIN;
        }

        if (port->pwr_role == TYPEC_SOURCE) {
                enum typec_cc_status cc_req = port->cc_req;

                port->ams = ams;

                if (ams == HARD_RESET) {
                        tcpm_set_cc(port, tcpm_rp_cc(port));
                        tcpm_pd_transmit(port, TCPC_TX_HARD_RESET, NULL);
                        tcpm_set_state(port, HARD_RESET_START, 0);
                        return ret;
                } else if (ams == SOFT_RESET_AMS) {
                        if (!port->explicit_contract)
                                tcpm_set_cc(port, tcpm_rp_cc(port));
                        tcpm_set_state(port, SOFT_RESET_SEND, 0);
                        return ret;
                } else if (tcpm_vdm_ams(port)) {
                        /* tSinkTx is enforced in vdm_run_state_machine */
                        if (port->negotiated_rev >= PD_REV30)
                                tcpm_set_cc(port, SINK_TX_NG);
                        return ret;
                }

                if (port->negotiated_rev >= PD_REV30)
                        tcpm_set_cc(port, SINK_TX_NG);

                switch (port->state) {
                case SRC_READY:
                case SRC_STARTUP:
                case SRC_SOFT_RESET_WAIT_SNK_TX:
                case SOFT_RESET:
                case SOFT_RESET_SEND:
                        if (port->negotiated_rev >= PD_REV30)
                                tcpm_set_state(port, AMS_START,
                                               cc_req == SINK_TX_OK ?
                                               PD_T_SINK_TX : 0);
                        else
                                tcpm_set_state(port, AMS_START, 0);
                        break;
                default:
                        if (port->negotiated_rev >= PD_REV30)
                                tcpm_set_state(port, SRC_READY,
                                               cc_req == SINK_TX_OK ?
                                               PD_T_SINK_TX : 0);
                        else
                                tcpm_set_state(port, SRC_READY, 0);
                        break;
                }
        } else {
                if (port->negotiated_rev >= PD_REV30 &&
                    !tcpm_sink_tx_ok(port) &&
                    ams != SOFT_RESET_AMS &&
                    ams != HARD_RESET) {
                        port->upcoming_state = INVALID_STATE;
                        tcpm_log(port, "Sink TX No Go");
                        return -EAGAIN;
                }

                port->ams = ams;

                if (ams == HARD_RESET) {
                        tcpm_pd_transmit(port, TCPC_TX_HARD_RESET, NULL);
                        tcpm_set_state(port, HARD_RESET_START, 0);
                        return ret;
                } else if (tcpm_vdm_ams(port)) {
                        return ret;
                }

                if (port->state == SNK_READY ||
                    port->state == SNK_SOFT_RESET)
                        tcpm_set_state(port, AMS_START, 0);
                else
                        tcpm_set_state(port, SNK_READY, 0);
        }

        return ret;
}

/*
 * VDM/VDO handling functions
 */
static void tcpm_queue_vdm(struct tcpm_port *port, const u32 header,
                           const u32 *data, int cnt)
{
        WARN_ON(!mutex_is_locked(&port->lock));

        /* Make sure we are not still processing a previous VDM packet */
        WARN_ON(port->vdm_state > VDM_STATE_DONE);

        port->vdo_count = cnt + 1;
        port->vdo_data[0] = header;
        memcpy(&port->vdo_data[1], data, sizeof(u32) * cnt);
        /* Set ready, vdm state machine will actually send */
        port->vdm_retries = 0;
        port->vdm_state = VDM_STATE_READY;
        port->vdm_sm_running = true;

        mod_vdm_delayed_work(port, 0);
}

static void tcpm_queue_vdm_unlocked(struct tcpm_port *port, const u32 header,
                                    const u32 *data, int cnt)
{
        mutex_lock(&port->lock);
        tcpm_queue_vdm(port, header, data, cnt);
        mutex_unlock(&port->lock);
}

static void svdm_consume_identity(struct tcpm_port *port, const u32 *p, int cnt)
{
        u32 vdo = p[VDO_INDEX_IDH];
        u32 product = p[VDO_INDEX_PRODUCT];

        memset(&port->mode_data, 0, sizeof(port->mode_data));

        port->partner_ident.id_header = vdo;
        port->partner_ident.cert_stat = p[VDO_INDEX_CSTAT];
        port->partner_ident.product = product;

        typec_partner_set_identity(port->partner);

        tcpm_log(port, "Identity: %04x:%04x.%04x",
                 PD_IDH_VID(vdo),
                 PD_PRODUCT_PID(product), product & 0xffff);
}

static bool svdm_consume_svids(struct tcpm_port *port, const u32 *p, int cnt)
{
        struct pd_mode_data *pmdata = &port->mode_data;
        int i;

        for (i = 1; i < cnt; i++) {
                u16 svid;

                svid = (p[i] >> 16) & 0xffff;
                if (!svid)
                        return false;

                if (pmdata->nsvids >= SVID_DISCOVERY_MAX)
                        goto abort;

                pmdata->svids[pmdata->nsvids++] = svid;
                tcpm_log(port, "SVID %d: 0x%x", pmdata->nsvids, svid);

                svid = p[i] & 0xffff;
                if (!svid)
                        return false;

                if (pmdata->nsvids >= SVID_DISCOVERY_MAX)
                        goto abort;

                pmdata->svids[pmdata->nsvids++] = svid;
                tcpm_log(port, "SVID %d: 0x%x", pmdata->nsvids, svid);
        }
        return true;
abort:
        tcpm_log(port, "SVID_DISCOVERY_MAX(%d) too low!", SVID_DISCOVERY_MAX);
        return false;
}

static void svdm_consume_modes(struct tcpm_port *port, const u32 *p, int cnt)
{
        struct pd_mode_data *pmdata = &port->mode_data;
        struct typec_altmode_desc *paltmode;
        int i;

        if (pmdata->altmodes >= ARRAY_SIZE(port->partner_altmode)) {
                /* Already logged in svdm_consume_svids() */
                return;
        }

        for (i = 1; i < cnt; i++) {
                paltmode = &pmdata->altmode_desc[pmdata->altmodes];
                memset(paltmode, 0, sizeof(*paltmode));

                paltmode->svid = pmdata->svids[pmdata->svid_index];
                paltmode->mode = i;
                paltmode->vdo = p[i];

                tcpm_log(port, " Alternate mode %d: SVID 0x%04x, VDO %d: 0x%08x",
                         pmdata->altmodes, paltmode->svid,
                         paltmode->mode, paltmode->vdo);

                pmdata->altmodes++;
        }
}

static void tcpm_register_partner_altmodes(struct tcpm_port *port)
{
        struct pd_mode_data *modep = &port->mode_data;
        struct typec_altmode *altmode;
        int i;

        for (i = 0; i < modep->altmodes; i++) {
                altmode = typec_partner_register_altmode(port->partner,
                                                &modep->altmode_desc[i]);
                if (IS_ERR(altmode)) {
                        tcpm_log(port, "Failed to register partner SVID 0x%04x",
                                 modep->altmode_desc[i].svid);
                        altmode = NULL;
                }
                port->partner_altmode[i] = altmode;
        }
}

#define supports_modal(port)    PD_IDH_MODAL_SUPP((port)->partner_ident.id_header)

static int tcpm_pd_svdm(struct tcpm_port *port, struct typec_altmode *adev,
                        const u32 *p, int cnt, u32 *response,
                        enum adev_actions *adev_action)
{
        struct typec_port *typec = port->typec_port;
        struct typec_altmode *pdev;
        struct pd_mode_data *modep;
        int svdm_version;
        int rlen = 0;
        int cmd_type;
        int cmd;
        int i;

        cmd_type = PD_VDO_CMDT(p[0]);
        cmd = PD_VDO_CMD(p[0]);

        tcpm_log(port, "Rx VDM cmd 0x%x type %d cmd %d len %d",
                 p[0], cmd_type, cmd, cnt);

        modep = &port->mode_data;

        pdev = typec_match_altmode(port->partner_altmode, ALTMODE_DISCOVERY_MAX,
                                   PD_VDO_VID(p[0]), PD_VDO_OPOS(p[0]));

        svdm_version = typec_get_negotiated_svdm_version(typec);
        if (svdm_version < 0)
                return 0;

        switch (cmd_type) {
        case CMDT_INIT:
                switch (cmd) {
                case CMD_DISCOVER_IDENT:
                        if (PD_VDO_VID(p[0]) != USB_SID_PD)
                                break;

                        if (PD_VDO_SVDM_VER(p[0]) < svdm_version) {
                                typec_partner_set_svdm_version(port->partner,
                                                               PD_VDO_SVDM_VER(p[0]));
                                svdm_version = PD_VDO_SVDM_VER(p[0]);
                        }

                        port->ams = DISCOVER_IDENTITY;
                        /*
                         * PD2.0 Spec 6.10.3: respond with NAK as DFP (data host)
                         * PD3.1 Spec 6.4.4.2.5.1: respond with NAK if "invalid field" or
                         * "wrong configuation" or "Unrecognized"
                         */
                        if ((port->data_role == TYPEC_DEVICE || svdm_version >= SVDM_VER_2_0) &&
                            port->nr_snk_vdo) {
                                if (svdm_version < SVDM_VER_2_0) {
                                        for (i = 0; i < port->nr_snk_vdo_v1; i++)
                                                response[i + 1] = port->snk_vdo_v1[i];
                                        rlen = port->nr_snk_vdo_v1 + 1;

                                } else {
                                        for (i = 0; i < port->nr_snk_vdo; i++)
                                                response[i + 1] = port->snk_vdo[i];
                                        rlen = port->nr_snk_vdo + 1;
                                }
                        }
                        break;
                case CMD_DISCOVER_SVID:
                        port->ams = DISCOVER_SVIDS;
                        break;
                case CMD_DISCOVER_MODES:
                        port->ams = DISCOVER_MODES;
                        break;
                case CMD_ENTER_MODE:
                        port->ams = DFP_TO_UFP_ENTER_MODE;
                        break;
                case CMD_EXIT_MODE:
                        port->ams = DFP_TO_UFP_EXIT_MODE;
                        break;
                case CMD_ATTENTION:
                        /* Attention command does not have response */
                        *adev_action = ADEV_ATTENTION;
                        return 0;
                default:
                        break;
                }
                if (rlen >= 1) {
                        response[0] = p[0] | VDO_CMDT(CMDT_RSP_ACK);
                } else if (rlen == 0) {
                        response[0] = p[0] | VDO_CMDT(CMDT_RSP_NAK);
                        rlen = 1;
                } else {
                        response[0] = p[0] | VDO_CMDT(CMDT_RSP_BUSY);
                        rlen = 1;
                }
                response[0] = (response[0] & ~VDO_SVDM_VERS_MASK) |
                              (VDO_SVDM_VERS(typec_get_negotiated_svdm_version(typec)));
                break;
        case CMDT_RSP_ACK:
                /* silently drop message if we are not connected */
                if (IS_ERR_OR_NULL(port->partner))
                        break;

                tcpm_ams_finish(port);

                switch (cmd) {
                case CMD_DISCOVER_IDENT:
                        if (PD_VDO_SVDM_VER(p[0]) < svdm_version)
                                typec_partner_set_svdm_version(port->partner,
                                                               PD_VDO_SVDM_VER(p[0]));
                        /* 6.4.4.3.1 */
                        svdm_consume_identity(port, p, cnt);
                        response[0] = VDO(USB_SID_PD, 1, typec_get_negotiated_svdm_version(typec),
                                          CMD_DISCOVER_SVID);
                        rlen = 1;
                        break;
                case CMD_DISCOVER_SVID:
                        /* 6.4.4.3.2 */
                        if (svdm_consume_svids(port, p, cnt)) {
                                response[0] = VDO(USB_SID_PD, 1, svdm_version, CMD_DISCOVER_SVID);
                                rlen = 1;
                        } else if (modep->nsvids && supports_modal(port)) {
                                response[0] = VDO(modep->svids[0], 1, svdm_version,
                                                  CMD_DISCOVER_MODES);
                                rlen = 1;
                        }
                        break;
                case CMD_DISCOVER_MODES:
                        /* 6.4.4.3.3 */
                        svdm_consume_modes(port, p, cnt);
                        modep->svid_index++;
                        if (modep->svid_index < modep->nsvids) {
                                u16 svid = modep->svids[modep->svid_index];
                                response[0] = VDO(svid, 1, svdm_version, CMD_DISCOVER_MODES);
                                rlen = 1;
                        } else {
                                tcpm_register_partner_altmodes(port);
                        }
                        break;
                case CMD_ENTER_MODE:
                        if (adev && pdev) {
                                typec_altmode_update_active(pdev, true);
                                *adev_action = ADEV_QUEUE_VDM_SEND_EXIT_MODE_ON_FAIL;
                        }
                        return 0;
                case CMD_EXIT_MODE:
                        if (adev && pdev) {
                                typec_altmode_update_active(pdev, false);
                                /* Back to USB Operation */
                                *adev_action = ADEV_NOTIFY_USB_AND_QUEUE_VDM;
                                return 0;
                        }
                        break;
                case VDO_CMD_VENDOR(0) ... VDO_CMD_VENDOR(15):
                        break;
                default:
                        /* Unrecognized SVDM */
                        response[0] = p[0] | VDO_CMDT(CMDT_RSP_NAK);
                        rlen = 1;
                        response[0] = (response[0] & ~VDO_SVDM_VERS_MASK) |
                                      (VDO_SVDM_VERS(svdm_version));
                        break;
                }
                break;
        case CMDT_RSP_NAK:
                tcpm_ams_finish(port);
                switch (cmd) {
                case CMD_DISCOVER_IDENT:
                case CMD_DISCOVER_SVID:
                case CMD_DISCOVER_MODES:
                case VDO_CMD_VENDOR(0) ... VDO_CMD_VENDOR(15):
                        break;
                case CMD_ENTER_MODE:
                        /* Back to USB Operation */
                        *adev_action = ADEV_NOTIFY_USB_AND_QUEUE_VDM;
                        return 0;
                default:
                        /* Unrecognized SVDM */
                        response[0] = p[0] | VDO_CMDT(CMDT_RSP_NAK);
                        rlen = 1;
                        response[0] = (response[0] & ~VDO_SVDM_VERS_MASK) |
                                      (VDO_SVDM_VERS(svdm_version));
                        break;
                }
                break;
        default:
                response[0] = p[0] | VDO_CMDT(CMDT_RSP_NAK);
                rlen = 1;
                response[0] = (response[0] & ~VDO_SVDM_VERS_MASK) |
                              (VDO_SVDM_VERS(svdm_version));
                break;
        }

        /* Informing the alternate mode drivers about everything */
        *adev_action = ADEV_QUEUE_VDM;
        return rlen;
}

static void tcpm_pd_handle_msg(struct tcpm_port *port,
                               enum pd_msg_request message,
                               enum tcpm_ams ams);

static void tcpm_handle_vdm_request(struct tcpm_port *port,
                                    const __le32 *payload, int cnt)
{
        enum adev_actions adev_action = ADEV_NONE;
        struct typec_altmode *adev;
        u32 p[PD_MAX_PAYLOAD];
        u32 response[8] = { };
        int i, rlen = 0;

        for (i = 0; i < cnt; i++)
                p[i] = le32_to_cpu(payload[i]);

        adev = typec_match_altmode(port->port_altmode, ALTMODE_DISCOVERY_MAX,
                                   PD_VDO_VID(p[0]), PD_VDO_OPOS(p[0]));

        if (port->vdm_state == VDM_STATE_BUSY) {
                /* If UFP responded busy retry after timeout */
                if (PD_VDO_CMDT(p[0]) == CMDT_RSP_BUSY) {
                        port->vdm_state = VDM_STATE_WAIT_RSP_BUSY;
                        port->vdo_retry = (p[0] & ~VDO_CMDT_MASK) |
                                CMDT_INIT;
                        mod_vdm_delayed_work(port, PD_T_VDM_BUSY);
                        return;
                }
                port->vdm_state = VDM_STATE_DONE;
        }

        if (PD_VDO_SVDM(p[0]) && (adev || tcpm_vdm_ams(port) || port->nr_snk_vdo)) {
                /*
                 * Here a SVDM is received (INIT or RSP or unknown). Set the vdm_sm_running in
                 * advance because we are dropping the lock but may send VDMs soon.
                 * For the cases of INIT received:
                 *  - If no response to send, it will be cleared later in this function.
                 *  - If there are responses to send, it will be cleared in the state machine.
                 * For the cases of RSP received:
                 *  - If no further INIT to send, it will be cleared later in this function.
                 *  - Otherwise, it will be cleared in the state machine if timeout or it will go
                 *    back here until no further INIT to send.
                 * For the cases of unknown type received:
                 *  - We will send NAK and the flag will be cleared in the state machine.
                 */
                port->vdm_sm_running = true;
                rlen = tcpm_pd_svdm(port, adev, p, cnt, response, &adev_action);
        } else {
                if (port->negotiated_rev >= PD_REV30)
                        tcpm_pd_handle_msg(port, PD_MSG_CTRL_NOT_SUPP, NONE_AMS);
        }

        /*
         * We are done with any state stored in the port struct now, except
         * for any port struct changes done by the tcpm_queue_vdm() call
         * below, which is a separate operation.
         *
         * So we can safely release the lock here; and we MUST release the
         * lock here to avoid an AB BA lock inversion:
         *
         * If we keep the lock here then the lock ordering in this path is:
         * 1. tcpm_pd_rx_handler take the tcpm port lock
         * 2. One of the typec_altmode_* calls below takes the alt-mode's lock
         *
         * And we also have this ordering:
         * 1. alt-mode driver takes the alt-mode's lock
         * 2. alt-mode driver calls tcpm_altmode_enter which takes the
         *    tcpm port lock
         *
         * Dropping our lock here avoids this.
         */
        mutex_unlock(&port->lock);

        if (adev) {
                switch (adev_action) {
                case ADEV_NONE:
                        break;
                case ADEV_NOTIFY_USB_AND_QUEUE_VDM:
                        WARN_ON(typec_altmode_notify(adev, TYPEC_STATE_USB, NULL));
                        typec_altmode_vdm(adev, p[0], &p[1], cnt);
                        break;
                case ADEV_QUEUE_VDM:
                        typec_altmode_vdm(adev, p[0], &p[1], cnt);
                        break;
                case ADEV_QUEUE_VDM_SEND_EXIT_MODE_ON_FAIL:
                        if (typec_altmode_vdm(adev, p[0], &p[1], cnt)) {
                                int svdm_version = typec_get_negotiated_svdm_version(
                                                                        port->typec_port);
                                if (svdm_version < 0)
                                        break;

                                response[0] = VDO(adev->svid, 1, svdm_version,
                                                  CMD_EXIT_MODE);
                                response[0] |= VDO_OPOS(adev->mode);
                                rlen = 1;
                        }
                        break;
                case ADEV_ATTENTION:
                        typec_altmode_attention(adev, p[1]);
                        break;
                }
        }

        /*
         * We must re-take the lock here to balance the unlock in
         * tcpm_pd_rx_handler, note that no changes, other then the
         * tcpm_queue_vdm call, are made while the lock is held again.
         * All that is done after the call is unwinding the call stack until
         * we return to tcpm_pd_rx_handler and do the unlock there.
         */
        mutex_lock(&port->lock);

        if (rlen > 0)
                tcpm_queue_vdm(port, response[0], &response[1], rlen - 1);
        else
                port->vdm_sm_running = false;
}

static void tcpm_send_vdm(struct tcpm_port *port, u32 vid, int cmd,
                          const u32 *data, int count)
{
        int svdm_version = typec_get_negotiated_svdm_version(port->typec_port);
        u32 header;

        if (svdm_version < 0)
                return;

        if (WARN_ON(count > VDO_MAX_SIZE - 1))
                count = VDO_MAX_SIZE - 1;

        /* set VDM header with VID & CMD */
        header = VDO(vid, ((vid & USB_SID_PD) == USB_SID_PD) ?
                        1 : (PD_VDO_CMD(cmd) <= CMD_ATTENTION),
                        svdm_version, cmd);
        tcpm_queue_vdm(port, header, data, count);
}

static unsigned int vdm_ready_timeout(u32 vdm_hdr)
{
        unsigned int timeout;
        int cmd = PD_VDO_CMD(vdm_hdr);

        /* its not a structured VDM command */
        if (!PD_VDO_SVDM(vdm_hdr))
                return PD_T_VDM_UNSTRUCTURED;

        switch (PD_VDO_CMDT(vdm_hdr)) {
        case CMDT_INIT:
                if (cmd == CMD_ENTER_MODE || cmd == CMD_EXIT_MODE)
                        timeout = PD_T_VDM_WAIT_MODE_E;
                else
                        timeout = PD_T_VDM_SNDR_RSP;
                break;
        default:
                if (cmd == CMD_ENTER_MODE || cmd == CMD_EXIT_MODE)
                        timeout = PD_T_VDM_E_MODE;
                else
                        timeout = PD_T_VDM_RCVR_RSP;
                break;
        }
        return timeout;
}

static void vdm_run_state_machine(struct tcpm_port *port)
{
        struct pd_message msg;
        int i, res = 0;
        u32 vdo_hdr = port->vdo_data[0];

        switch (port->vdm_state) {
        case VDM_STATE_READY:
                /* Only transmit VDM if attached */
                if (!port->attached) {
                        port->vdm_state = VDM_STATE_ERR_BUSY;
                        break;
                }

                /*
                 * if there's traffic or we're not in PDO ready state don't send
                 * a VDM.
                 */
                if (port->state != SRC_READY && port->state != SNK_READY) {
                        port->vdm_sm_running = false;
                        break;
                }

                /* TODO: AMS operation for Unstructured VDM */
                if (PD_VDO_SVDM(vdo_hdr) && PD_VDO_CMDT(vdo_hdr) == CMDT_INIT) {
                        switch (PD_VDO_CMD(vdo_hdr)) {
                        case CMD_DISCOVER_IDENT:
                                res = tcpm_ams_start(port, DISCOVER_IDENTITY);
                                if (res == 0)
                                        port->send_discover = false;
                                else if (res == -EAGAIN)
                                        mod_send_discover_delayed_work(port,
                                                                       SEND_DISCOVER_RETRY_MS);
                                break;
                        case CMD_DISCOVER_SVID:
                                res = tcpm_ams_start(port, DISCOVER_SVIDS);
                                break;
                        case CMD_DISCOVER_MODES:
                                res = tcpm_ams_start(port, DISCOVER_MODES);
                                break;
                        case CMD_ENTER_MODE:
                                res = tcpm_ams_start(port, DFP_TO_UFP_ENTER_MODE);
                                break;
                        case CMD_EXIT_MODE:
                                res = tcpm_ams_start(port, DFP_TO_UFP_EXIT_MODE);
                                break;
                        case CMD_ATTENTION:
                                res = tcpm_ams_start(port, ATTENTION);
                                break;
                        case VDO_CMD_VENDOR(0) ... VDO_CMD_VENDOR(15):
                                res = tcpm_ams_start(port, STRUCTURED_VDMS);
                                break;
                        default:
                                res = -EOPNOTSUPP;
                                break;
                        }

                        if (res < 0) {
                                port->vdm_state = VDM_STATE_ERR_BUSY;
                                return;
                        }
                }

                port->vdm_state = VDM_STATE_SEND_MESSAGE;
                mod_vdm_delayed_work(port, (port->negotiated_rev >= PD_REV30 &&
                                            port->pwr_role == TYPEC_SOURCE &&
                                            PD_VDO_SVDM(vdo_hdr) &&
                                            PD_VDO_CMDT(vdo_hdr) == CMDT_INIT) ?
                                           PD_T_SINK_TX : 0);
                break;
        case VDM_STATE_WAIT_RSP_BUSY:
                port->vdo_data[0] = port->vdo_retry;
                port->vdo_count = 1;
                port->vdm_state = VDM_STATE_READY;
                tcpm_ams_finish(port);
                break;
        case VDM_STATE_BUSY:
                port->vdm_state = VDM_STATE_ERR_TMOUT;
                if (port->ams != NONE_AMS)
                        tcpm_ams_finish(port);
                break;
        case VDM_STATE_ERR_SEND:
                /*
                 * A partner which does not support USB PD will not reply,
                 * so this is not a fatal error. At the same time, some
                 * devices may not return GoodCRC under some circumstances,
                 * so we need to retry.
                 */
                if (port->vdm_retries < 3) {
                        tcpm_log(port, "VDM Tx error, retry");
                        port->vdm_retries++;
                        port->vdm_state = VDM_STATE_READY;
                        if (PD_VDO_SVDM(vdo_hdr) && PD_VDO_CMDT(vdo_hdr) == CMDT_INIT)
                                tcpm_ams_finish(port);
                } else {
                        tcpm_ams_finish(port);
                }
                break;