// 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/jiffies.h>
#include <linux/kernel.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 <linux/workqueue.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(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(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(ERROR_RECOVERY),                      \
        S(PORT_RESET),                          \
        S(PORT_RESET_WAIT_OFF)

#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 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,
};

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,
};

/* Events from low level driver */

#define TCPM_CC_EVENT           BIT(0)
#define TCPM_VBUS_EVENT         BIT(1)
#define TCPM_RESET_EVENT        BIT(2)

#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)

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];
};

struct pd_pps_data {
        u32 min_volt;
        u32 max_volt;
        u32 max_curr;
        u32 out_volt;
        u32 op_curr;
        bool supported;
        bool active;
};

struct tcpm_port {
        struct device *dev;

        struct mutex lock;              /* tcpm state machine lock */
        struct workqueue_struct *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;
        bool vbus_present;
        bool vbus_never_low;
        bool vbus_source;
        bool vbus_charge;

        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;
        unsigned long delayed_runtime;
        unsigned long delay_ms;

        spinlock_t pd_event_lock;
        u32 pd_events;

        struct work_struct event_work;
        struct delayed_work state_machine;
        struct delayed_work vdm_state_machine;
        bool state_machine_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[VDO_MAX_OBJECTS];
        unsigned int nr_snk_vdo;

        unsigned int operating_snk_mw;
        bool update_sink_caps;

        /* Requested current / voltage */
        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;

#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 work_struct work;
        struct tcpm_port *port;
        struct pd_message msg;
};

#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)

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_file(name, S_IFREG | 0444, usb_debug_root,
                                           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 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);
        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;
                return 0;
        case TCPC_TX_DISCARDED:
                return -EAGAIN;
        case TCPC_TX_FAILED:
        default:
                return -EIO;
        }
}

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;

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

        return ret;
}

/*
 * 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 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 (data == TYPEC_HOST)
                usb_role = USB_ROLE_HOST;
        else
                usb_role = USB_ROLE_DEVICE;

        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;
}

static int tcpm_pd_send_source_caps(struct tcpm_port *port)
{
        struct pd_message msg;
        int i;

        memset(&msg, 0, sizeof(msg));
        if (!port->nr_src_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,
                                          port->nr_src_pdo);
        }
        for (i = 0; i < port->nr_src_pdo; i++)
                msg.payload[i] = cpu_to_le32(port->src_pdo[i]);

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

static int tcpm_pd_send_sink_caps(struct tcpm_port *port)
{
        struct pd_message msg;
        int i;

        memset(&msg, 0, sizeof(msg));
        if (!port->nr_snk_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,
                                          port->nr_snk_pdo);
        }
        for (i = 0; i < port->nr_snk_pdo; i++)
                msg.payload[i] = cpu_to_le32(port->snk_pdo[i]);

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

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",
                         tcpm_states[port->state], tcpm_states[state],
                         delay_ms);
                port->delayed_state = state;
                mod_delayed_work(port->wq, &port->state_machine,
                                 msecs_to_jiffies(delay_ms));
                port->delayed_runtime = jiffies + msecs_to_jiffies(delay_ms);
                port->delay_ms = delay_ms;
        } else {
                tcpm_log(port, "state change %s -> %s",
                         tcpm_states[port->state], tcpm_states[state]);
                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_delayed_work(port->wq, &port->state_machine, 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",
                         delay_ms ? "delayed " : "",
                         tcpm_states[port->state], tcpm_states[state],
                         delay_ms, tcpm_states[port->enter_state]);
}

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

/*
 * VDM/VDO handling functions
 */
static void tcpm_queue_vdm(struct tcpm_port *port, const u32 header,
                           const u32 *data, int cnt)
{
        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;
}

static void svdm_consume_identity(struct tcpm_port *port, const __le32 *payload,
                                  int cnt)
{
        u32 vdo = le32_to_cpu(payload[VDO_INDEX_IDH]);
        u32 product = le32_to_cpu(payload[VDO_INDEX_PRODUCT]);

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

        port->partner_ident.id_header = vdo;
        port->partner_ident.cert_stat = le32_to_cpu(payload[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 __le32 *payload,
                               int cnt)
{
        struct pd_mode_data *pmdata = &port->mode_data;
        int i;

        for (i = 1; i < cnt; i++) {
                u32 p = le32_to_cpu(payload[i]);
                u16 svid;

                svid = (p >> 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 & 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 __le32 *payload,
                               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 = le32_to_cpu(payload[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 (!altmode)
                        tcpm_log(port, "Failed to register partner SVID 0x%04x",
                                 modep->altmode_desc[i].svid);
                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, const __le32 *payload, int cnt,
                        u32 *response)
{
        struct typec_altmode *adev;
        struct typec_altmode *pdev;
        struct pd_mode_data *modep;
        u32 p[PD_MAX_PAYLOAD];
        int rlen = 0;
        int cmd_type;
        int cmd;
        int i;

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

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

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

        switch (cmd_type) {
        case CMDT_INIT:
                switch (cmd) {
                case CMD_DISCOVER_IDENT:
                        /* 6.4.4.3.1: Only respond as UFP (device) */
                        if (port->data_role == TYPEC_DEVICE &&
                            port->nr_snk_vdo) {
                                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:
                        break;
                case CMD_DISCOVER_MODES:
                        break;
                case CMD_ENTER_MODE:
                        break;
                case CMD_EXIT_MODE:
                        break;
                case CMD_ATTENTION:
                        /* Attention command does not have response */
                        if (adev)
                                typec_altmode_attention(adev, p[1]);
                        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;
                }
                break;
        case CMDT_RSP_ACK:
                /* silently drop message if we are not connected */
                if (IS_ERR_OR_NULL(port->partner))
                        break;

                switch (cmd) {
                case CMD_DISCOVER_IDENT:
                        /* 6.4.4.3.1 */
                        svdm_consume_identity(port, payload, cnt);
                        response[0] = VDO(USB_SID_PD, 1, CMD_DISCOVER_SVID);
                        rlen = 1;
                        break;
                case CMD_DISCOVER_SVID:
                        /* 6.4.4.3.2 */
                        if (svdm_consume_svids(port, payload, cnt)) {
                                response[0] = VDO(USB_SID_PD, 1,
                                                  CMD_DISCOVER_SVID);
                                rlen = 1;
                        } else if (modep->nsvids && supports_modal(port)) {
                                response[0] = VDO(modep->svids[0], 1,
                                                  CMD_DISCOVER_MODES);
                                rlen = 1;
                        }
                        break;
                case CMD_DISCOVER_MODES:
                        /* 6.4.4.3.3 */
                        svdm_consume_modes(port, payload, cnt);
                        modep->svid_index++;
                        if (modep->svid_index < modep->nsvids) {
                                u16 svid = modep->svids[modep->svid_index];
                                response[0] = VDO(svid, 1, 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);

                                if (typec_altmode_vdm(adev, p[0], &p[1], cnt)) {
                                        response[0] = VDO(adev->svid, 1,
                                                          CMD_EXIT_MODE);
                                        response[0] |= VDO_OPOS(adev->mode);
                                        return 1;
                                }
                        }
                        return 0;
                case CMD_EXIT_MODE:
                        if (adev && pdev) {
                                typec_altmode_update_active(pdev, false);

                                /* Back to USB Operation */
                                WARN_ON(typec_altmode_notify(adev,
                                                             TYPEC_STATE_USB,
                                                             NULL));
                        }
                        break;
                default:
                        break;
                }
                break;
        case CMDT_RSP_NAK:
                switch (cmd) {
                case CMD_ENTER_MODE:
                        /* Back to USB Operation */
                        if (adev)
                                WARN_ON(typec_altmode_notify(adev,
                                                             TYPEC_STATE_USB,
                                                             NULL));
                        break;
                default:
                        break;
                }
                break;
        default:
                break;
        }

        /* Informing the alternate mode drivers about everything */
        if (adev)
                typec_altmode_vdm(adev, p[0], &p[1], cnt);

        return rlen;
}

static void tcpm_handle_vdm_request(struct tcpm_port *port,
                                    const __le32 *payload, int cnt)
{
        int rlen = 0;
        u32 response[8] = { };
        u32 p0 = le32_to_cpu(payload[0]);

        if (port->vdm_state == VDM_STATE_BUSY) {
                /* If UFP responded busy retry after timeout */
                if (PD_VDO_CMDT(p0) == CMDT_RSP_BUSY) {
                        port->vdm_state = VDM_STATE_WAIT_RSP_BUSY;
                        port->vdo_retry = (p0 & ~VDO_CMDT_MASK) |
                                CMDT_INIT;
                        mod_delayed_work(port->wq, &port->vdm_state_machine,
                                         msecs_to_jiffies(PD_T_VDM_BUSY));
                        return;
                }
                port->vdm_state = VDM_STATE_DONE;
        }

        if (PD_VDO_SVDM(p0))
                rlen = tcpm_pd_svdm(port, payload, cnt, response);

        if (rlen > 0) {
                tcpm_queue_vdm(port, response[0], &response[1], rlen - 1);
                mod_delayed_work(port->wq, &port->vdm_state_machine, 0);
        }
}

static void tcpm_send_vdm(struct tcpm_port *port, u32 vid, int cmd,
                          const u32 *data, int count)
{
        u32 header;

        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), cmd);
        tcpm_queue_vdm(port, header, data, count);

        mod_delayed_work(port->wq, &port->vdm_state_machine, 0);
}

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;

        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)
                        break;

                /* Prepare and send VDM */
                memset(&msg, 0, sizeof(msg));
                msg.header = PD_HEADER_LE(PD_DATA_VENDOR_DEF,
                                          port->pwr_role,
                                          port->data_role,
                                          port->negotiated_rev,
                                          port->message_id, port->vdo_count);
                for (i = 0; i < port->vdo_count; i++)
                        msg.payload[i] = cpu_to_le32(port->vdo_data[i]);
                res = tcpm_pd_transmit(port, TCPC_TX_SOP, &msg);
                if (res < 0) {
                        port->vdm_state = VDM_STATE_ERR_SEND;
                } else {
                        unsigned long timeout;

                        port->vdm_retries = 0;
                        port->vdm_state = VDM_STATE_BUSY;
                        timeout = vdm_ready_timeout(port->vdo_data[0]);
                        mod_delayed_work(port->wq, &port->vdm_state_machine,
                                         timeout);
                }
                break;
        case VDM_STATE_WAIT_RSP_BUSY:
                port->vdo_data[0] = port->vdo_retry;
                port->vdo_count = 1;
                port->vdm_state = VDM_STATE_READY;
                break;
        case VDM_STATE_BUSY:
                port->vdm_state = VDM_STATE_ERR_TMOUT;
                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;
                }
                break;
        default:
                break;
        }
}

static void vdm_state_machine_work(struct work_struct *work)
{
        struct tcpm_port *port = container_of(work, struct tcpm_port,
                                              vdm_state_machine.work);
        enum vdm_states prev_state;

        mutex_lock(&port->lock);

        /*
         * Continue running as long as the port is not busy and there was
         * a state change.
         */
        do {
                prev_state = port->vdm_state;
                vdm_run_state_machine(port);
        } while (port->vdm_state != prev_state &&
                 port->vdm_state != VDM_STATE_BUSY);

        mutex_unlock(&port->lock);
}

enum pdo_err {
        PDO_NO_ERR,
        PDO_ERR_NO_VSAFE5V,
        PDO_ERR_VSAFE5V_NOT_FIRST,
        PDO_ERR_PDO_TYPE_NOT_IN_ORDER,
        PDO_ERR_FIXED_NOT_SORTED,
        PDO_ERR_VARIABLE_BATT_NOT_SORTED,
        PDO_ERR_DUPE_PDO,
        PDO_ERR_PPS_APDO_NOT_SORTED,
        PDO_ERR_DUPE_PPS_APDO,
};

static const char * const pdo_err_msg[] = {
        [PDO_ERR_NO_VSAFE5V] =
        " err: source/sink caps should atleast have vSafe5V",
        [PDO_ERR_VSAFE5V_NOT_FIRST] =
        " err: vSafe5V Fixed Supply Object Shall always be the first object",
        [PDO_ERR_PDO_TYPE_NOT_IN_ORDER] =
        " err: PDOs should be in the following order: Fixed; Battery; Variable",
        [PDO_ERR_FIXED_NOT_SORTED] =
        " err: Fixed supply pdos should be in increasing order of their fixed voltage",
        [PDO_ERR_VARIABLE_BATT_NOT_SORTED] =
        " err: Variable/Battery supply pdos should be in increasing order of their minimum voltage",
        [PDO_ERR_DUPE_PDO] =
        " err: Variable/Batt supply pdos cannot have same min/max voltage",
        [PDO_ERR_PPS_APDO_NOT_SORTED] =
        " err: Programmable power supply apdos should be in increasing order of their maximum voltage",
        [PDO_ERR_DUPE_PPS_APDO] =
        " err: Programmable power supply apdos cannot have same min/max voltage and max current",
};

static enum pdo_err tcpm_caps_err(struct tcpm_port *port, const u32 *pdo,
                                  unsigned int nr_pdo)
{
        unsigned int i;

        /* Should at least contain vSafe5v */
        if (nr_pdo < 1)
                return PDO_ERR_NO_VSAFE5V;

        /* The vSafe5V Fixed Supply Object Shall always be the first object */
        if (pdo_type(pdo[0]) != PDO_TYPE_FIXED ||
            pdo_fixed_voltage(pdo[0]) != VSAFE5V)
                return PDO_ERR_VSAFE5V_NOT_FIRST;

        for (i = 1; i < nr_pdo; i++) {
                if (pdo_type(pdo[i]) < pdo_type(pdo[i - 1])) {
                        return PDO_ERR_PDO_TYPE_NOT_IN_ORDER;
                } else if (pdo_type(pdo[i]) == pdo_type(pdo[i - 1])) {
                        enum pd_pdo_type type = pdo_type(pdo[i]);

                        switch (type) {
                        /*
                         * The remaining Fixed Supply Objects, if
                         * present, shall be sent in voltage order;
                         * lowest to highest.
                         */
                        case PDO_TYPE_FIXED:
                                if (pdo_fixed_voltage(pdo[i]) <=
                                    pdo_fixed_voltage(pdo[i - 1]))
                                        return PDO_ERR_FIXED_NOT_SORTED;
                                break;
                        /*
                         * The Battery Supply Objects and Variable
                         * supply, if present shall be sent in Minimum
                         * Voltage order; lowest to highest.
                         */
                        case PDO_TYPE_VAR:
                        case PDO_TYPE_BATT:
                                if (pdo_min_voltage(pdo[i]) <
                                    pdo_min_voltage(pdo[i - 1]))
                                        return PDO_ERR_VARIABLE_BATT_NOT_SORTED;
                                else if ((pdo_min_voltage(pdo[i]) ==
                                          pdo_min_voltage(pdo[i - 1])) &&
                                         (pdo_max_voltage(pdo[i]) ==
                                          pdo_max_voltage(pdo[i - 1])))
                                        return PDO_ERR_DUPE_PDO;
                                break;
                        /*
                         * The Programmable Power Supply APDOs, if present,
                         * shall be sent in Maximum Voltage order;
                         * lowest to highest.
                         */
                        case PDO_TYPE_APDO:
                                if (pdo_apdo_type(pdo[i]) != APDO_TYPE_PPS)
                                        break;

                                if (pdo_pps_apdo_max_voltage(pdo[i]) <
                                    pdo_pps_apdo_max_voltage(pdo[i - 1]))
                                        return PDO_ERR_PPS_APDO_NOT_SORTED;
                                else if (pdo_pps_apdo_min_voltage(pdo[i]) ==
                                          pdo_pps_apdo_min_voltage(pdo[i - 1]) &&
                                         pdo_pps_apdo_max_voltage(pdo[i]) ==
                                          pdo_pps_apdo_max_voltage(pdo[i - 1]) &&
                                         pdo_pps_apdo_max_current(pdo[i]) ==
                                          pdo_pps_apdo_max_current(pdo[i - 1]))
                                        return PDO_ERR_DUPE_PPS_APDO;
                                break;
                        default:
                                tcpm_log_force(port, " Unknown pdo type");
                        }
                }
        }

        return PDO_NO_ERR;
}

static int tcpm_validate_caps(struct tcpm_port *port, const u32 *pdo,
                              unsigned int nr_pdo)
{
        enum pdo_err err_index = tcpm_caps_err(port, pdo, nr_pdo);

        if (err_index != PDO_NO_ERR) {
                tcpm_log_force(port, " %s", pdo_err_msg[err_index]);
                return -EINVAL;
        }

        return 0;
}

static int tcpm_altmode_enter(struct typec_altmode *altmode, u32 *vdo)
{
        struct tcpm_port *port = typec_altmode_get_drvdata(altmode);
        u32 header;

        mutex_lock(&port->lock);
        header = VDO(altmode->svid, vdo ? 2 : 1, CMD_ENTER_MODE);
        header |= VDO_OPOS(altmode->mode);

        tcpm_queue_vdm(port, header, vdo, vdo ? 1 : 0);
        mod_delayed_work(port->wq, &port->vdm_state_machine, 0);
        mutex_unlock(&port->lock);

        return 0;
}

static int tcpm_altmode_exit(struct typec_altmode *altmode)
{
        struct tcpm_port *port = typec_altmode_get_drvdata(altmode);
        u32 header;

        mutex_lock(&port->lock);
        header = VDO(altmode->svid, 1, CMD_EXIT_MODE);
        header |= VDO_OPOS(altmode->mode);

        tcpm_queue_vdm(port, header, NULL, 0);
        mod_delayed_work(port->wq, &port->vdm_state_machine, 0);
        mutex_unlock(&port->lock);

        return 0;
}

static int tcpm_altmode_vdm(struct typec_altmode *altmode,
                            u32 header, const u32 *data, int count)
{
        struct tcpm_port *port = typec_altmode_get_drvdata(altmode);

        mutex_lock(&port->lock);
        tcpm_queue_vdm(port, header, data, count - 1);
        mod_delayed_work(port->wq, &port->vdm_state_machine, 0);
        mutex_unlock(&port->lock);

        return 0;
}

static const struct typec_altmode_ops tcpm_altmode_ops = {
        .enter = tcpm_altmode_enter,
        .exit = tcpm_altmode_exit,
        .vdm = tcpm_altmode_vdm,
};

/*
 * PD (data, control) command handling functions
 */
static inline enum tcpm_state ready_state(struct tcpm_port *port)
{
        if (port->pwr_role == TYPEC_SOURCE)
                return SRC_READY;
        else
                return SNK_READY;
}

static int tcpm_pd_send_control(struct tcpm_port *port,
                                enum pd_ctrl_msg_type type);

static void tcpm_handle_alert(struct tcpm_port *port, const __le32 *payload,
                              int cnt)
{
        u32 p0 = le32_to_cpu(payload[0]);
        unsigned int type = usb_pd_ado_type(p0);

        if (!type) {
                tcpm_log(port, "Alert message received with no type");
                return;
        }

        /* Just handling non-battery alerts for now */
        if (!(type & USB_PD_ADO_TYPE_BATT_STATUS_CHANGE)) {
                switch (port->state) {
                case SRC_READY:
                case SNK_READY:
                        tcpm_set_state(port, GET_STATUS_SEND, 0);
                        break;
                default:
                        tcpm_queue_message(port, PD_MSG_CTRL_WAIT);
                        break;
                }
        }
}

static void tcpm_pd_data_request(struct tcpm_port *port,
                                 const struct pd_message *msg)
{
        enum pd_data_msg_type type = pd_header_type_le(msg->header);
        unsigned int cnt = pd_header_cnt_le(msg->header);
        unsigned int rev = pd_header_rev_le(msg->header);
        unsigned int i;

        switch (type) {
        case PD_DATA_SOURCE_CAP:
                if (port->pwr_role != TYPEC_SINK)
                        break;

                for (i = 0; i < cnt; i++)
                        port->source_caps[i] = le32_to_cpu(msg->payload[i]);

                port->nr_source_caps = cnt;

                tcpm_log_source_caps(port);

                tcpm_validate_caps(port, port->source_caps,
                                   port->nr_source_caps);

                /*
                 * Adjust revision in subsequent message headers, as required,
                 * to comply with 6.2.1.1.5 of the USB PD 3.0 spec. We don't
                 * support Rev 1.0 so just do nothing in that scenario.
                 */
                if (rev == PD_REV10)
                        break;

                if (rev < PD_MAX_REV)
                        port->negotiated_rev = rev;

                /*
                 * This message may be received even if VBUS is not
                 * present. This is quite unexpected; see USB PD
                 * specification, sections 8.3.3.6.3.1 and 8.3.3.6.3.2.
                 * However, at the same time, we must be ready to
                 * receive this message and respond to it 15ms after
                 * receiving PS_RDY during power swap operations, no matter
                 * if VBUS is available or not (USB PD specification,
                 * section 6.5.9.2).
                 * So we need to accept the message either way,
                 * but be prepared to keep waiting for VBUS after it was
                 * handled.
                 */
                tcpm_set_state(port, SNK_NEGOTIATE_CAPABILITIES, 0);
                break;
        case PD_DATA_REQUEST:
                if (port->pwr_role != TYPEC_SOURCE ||
                    cnt != 1) {
                        tcpm_queue_message(port, PD_MSG_CTRL_REJECT);
                        break;
                }

                /*
                 * Adjust revision in subsequent message headers, as required,
                 * to comply with 6.2.1.1.5 of the USB PD 3.0 spec. We don't
                 * support Rev 1.0 so just reject in that scenario.
                 */
                if (rev == PD_REV10) {
                        tcpm_queue_message(port, PD_MSG_CTRL_REJECT);
                        break;
                }

                if (rev < PD_MAX_REV)
                        port->negotiated_rev = rev;

                port->sink_request = le32_to_cpu(msg->payload[0]);
                tcpm_set_state(port, SRC_NEGOTIATE_CAPABILITIES, 0);
                break;
        case PD_DATA_SINK_CAP:
                /* We don't do anything with this at the moment... */
                for (i = 0; i < cnt; i++)
                        port->sink_caps[i] = le32_to_cpu(msg->payload[i]);
                port->nr_sink_caps = cnt;
                break;
        case PD_DATA_VENDOR_DEF:
                tcpm_handle_vdm_request(port, msg->payload, cnt);
                break;
        case PD_DATA_BIST:
                if (port->state == SRC_READY || port->state == SNK_READY) {
                        port->bist_request = le32_to_cpu(msg->payload[0]);
                        tcpm_set_state(port, BIST_RX, 0);
                }
                break;
        case PD_DATA_ALERT:
                tcpm_handle_alert(port, msg->payload, cnt);
                break;
        case PD_DATA_BATT_STATUS:
        case PD_DATA_GET_COUNTRY_INFO:
                /* Currently unsupported */
                tcpm_queue_message(port, PD_MSG_CTRL_NOT_SUPP);
                break;
        default:
                tcpm_log(port, "Unhandled data message type %#x", type);
                break;
        }
}

static void tcpm_pps_complete(struct tcpm_port *port, int result)
{
        if (port->pps_pending) {
                port->pps_status = result;
                port->pps_pending = false;
                complete(&port->pps_complete);
        }
}

static void tcpm_pd_ctrl_request(struct tcpm_port *port,
                                 const struct pd_message *msg)
{
        enum pd_ctrl_msg_type type = pd_header_type_le(msg->header);
        enum tcpm_state next_state;

        switch (type) {
        case PD_CTRL_GOOD_CRC:
        case PD_CTRL_PING:
                break;
        case PD_CTRL_GET_SOURCE_CAP:
                switch (port->state) {
                case SRC_READY:
                case SNK_READY:
                        tcpm_queue_message(port, PD_MSG_DATA_SOURCE_CAP);
                        break;
                default:
                        tcpm_queue_message(port, PD_MSG_CTRL_REJECT);
                        break;
                }
                break;
        case PD_CTRL_GET_SINK_CAP:
                switch (port->state) {
                case SRC_READY:
                case SNK_READY:
                        tcpm_queue_message(port, PD_MSG_DATA_SINK_CAP);
                        break;
                default:
                        tcpm_queue_message(port, PD_MSG_CTRL_REJECT);
                        break;
                }
                break;
        case PD_CTRL_GOTO_MIN:
                break;
        case PD_CTRL_PS_RDY:
                switch (port->state) {
                case SNK_TRANSITION_SINK:
                        if (port->vbus_present) {
                                tcpm_set_current_limit(port,
                                                       port->current_limit,
                                                       port->supply_voltage);
                                port->explicit_contract = true;
                                tcpm_set_state(port, SNK_READY, 0);
                        } else {
                                /*
                                 * Seen after power swap. Keep waiting for VBUS
                                 * in a transitional state.
                                 */
                                tcpm_set_state(port,
                                               SNK_TRANSITION_SINK_VBUS, 0);
                        }
                        break;
                case PR_SWAP_SRC_SNK_SOURCE_OFF_CC_DEBOUNCED:
                        tcpm_set_state(port, PR_SWAP_SRC_SNK_SINK_ON, 0);
                        break;
                case PR_SWAP_SNK_SRC_SINK_OFF:
                        tcpm_set_state(port, PR_SWAP_SNK_SRC_SOURCE_ON, 0);
                        break;
                case VCONN_SWAP_WAIT_FOR_VCONN:
                        tcpm_set_state(port, VCONN_SWAP_TURN_OFF_VCONN, 0);
                        break;
                default:
                        break;
                }
                break;
        case PD_CTRL_REJECT:
        case PD_CTRL_WAIT:
        case PD_CTRL_NOT_SUPP:
                switch (port->state) {
                case SNK_NEGOTIATE_CAPABILITIES:
                        /* USB PD specification, Figure 8-43 */
                        if (port->explicit_contract)
                                next_state = SNK_READY;
                        else
                                next_state = SNK_WAIT_CAPABILITIES;
                        tcpm_set_state(port, next_state, 0);
                        break;
                case SNK_NEGOTIATE_PPS_CAPABILITIES:
                        /* Revert data back from any requested PPS updates */
                        port->pps_data.out_volt = port->supply_voltage;
                        port->pps_data.op_curr = port->current_limit;
                        port->pps_status = (type == PD_CTRL_WAIT ?
                                            -EAGAIN : -EOPNOTSUPP);
                        tcpm_set_state(port, SNK_READY, 0);
                        break;
                case DR_SWAP_SEND:
                        port->swap_status = (type == PD_CTRL_WAIT ?
                                             -EAGAIN : -EOPNOTSUPP);
                        tcpm_set_state(port, DR_SWAP_CANCEL, 0);
                        break;
                case PR_SWAP_SEND:
                        port->swap_status = (type == PD_CTRL_WAIT ?
                                             -EAGAIN : -EOPNOTSUPP);
                        tcpm_set_state(port, PR_SWAP_CANCEL, 0);
                        break;
                case VCONN_SWAP_SEND:
                        port->swap_status = (type == PD_CTRL_WAIT ?
                                             -EAGAIN : -EOPNOTSUPP);
                        tcpm_set_state(port, VCONN_SWAP_CANCEL, 0);
                        break;
                default:
                        break;
                }
                break;
        case PD_CTRL_ACCEPT:
                switch (port->state) {
                case SNK_NEGOTIATE_CAPABILITIES:
                        port->pps_data.active = false;
                        tcpm_set_state(port, SNK_TRANSITION_SINK, 0);
                        break;
                case SNK_NEGOTIATE_PPS_CAPABILITIES:
                        port->pps_data.active = true;
                        port->supply_voltage = port->pps_data.out_volt;
                        port->current_limit = port->pps_data.op_curr;
                        tcpm_set_state(port, SNK_TRANSITION_SINK, 0);
                        break;
                case SOFT_RESET_SEND:
                        port->message_id = 0;
                        port->rx_msgid = -1;
                        if (port->pwr_role == TYPEC_SOURCE)
                                next_state = SRC_SEND_CAPABILITIES;
                        else
                                next_state = SNK_WAIT_CAPABILITIES;
                        tcpm_set_state(port, next_state, 0);
                        break;
                case DR_SWAP_SEND:
                        tcpm_set_state(port, DR_SWAP_CHANGE_DR, 0);
                        break;
                case PR_SWAP_SEND:
                        tcpm_set_state(port, PR_SWAP_START, 0);
                        break;
                case VCONN_SWAP_SEND:
                        tcpm_set_state(port, VCONN_SWAP_START, 0);
                        break;
                default:
                        break;
                }
                break;
        case PD_CTRL_SOFT_RESET:
                tcpm_set_state(port, SOFT_RESET, 0);
                break;
        case PD_CTRL_DR_SWAP:
                if (port->port_type != TYPEC_PORT_DRP) {
                        tcpm_queue_message(port, PD_MSG_CTRL_REJECT);
                        break;
                }
                /*
                 * XXX
                 * 6.3.9: If an alternate mode is active, a request to swap
                 * alternate modes shall trigger a port reset.
                 */
                switch (port->state) {
                case SRC_READY:
                case SNK_READY:
                        tcpm_set_state(port, DR_SWAP_ACCEPT, 0);
                        break;
                default:
                        tcpm_queue_message(port, PD_MSG_CTRL_WAIT);
                        break;
                }
                break;
        case PD_CTRL_PR_SWAP:
                if (port->port_type != TYPEC_PORT_DRP) {
                        tcpm_queue_message(port, PD_MSG_CTRL_REJECT);
                        break;
                }
                switch (port->state) {
                case SRC_READY:
                case SNK_READY:
                        tcpm_set_state(port, PR_SWAP_ACCEPT, 0);
                        break;
                default:
                        tcpm_queue_message(port, PD_MSG_CTRL_WAIT);
                        break;
                }
                break;
        case PD_CTRL_VCONN_SWAP:
                switch (port->state) {
                case SRC_READY:
                case SNK_READY:
                        tcpm_set_state(port, VCONN_SWAP_ACCEPT, 0);
                        break;
                default:
                        tcpm_queue_message(port, PD_MSG_CTRL_WAIT);
                        break;
                }
                break;
        case PD_CTRL_GET_SOURCE_CAP_EXT:
        case PD_CTRL_GET_STATUS:
        case PD_CTRL_FR_SWAP:
        case PD_CTRL_GET_PPS_STATUS:
        case PD_CTRL_GET_COUNTRY_CODES:
                /* Currently not supported */
                tcpm_queue_message(port, PD_MSG_CTRL_NOT_SUPP);
                break;
        default:
                tcpm_log(port, "Unhandled ctrl message type %#x", type);
                break;
        }
}

static void tcpm_pd_ext_msg_request(struct tcpm_port *port,
                                    const struct pd_message *msg)
{
        enum pd_ext_msg_type type = pd_header_type_le(msg->header);
        unsigned int data_size = pd_ext_header_data_size_le(msg->ext_msg.header);

        if (!(msg->ext_msg.header & PD_EXT_HDR_CHUNKED)) {
                tcpm_log(port, "Unchunked extended messages unsupported");
                return;
        }

        if (data_size > PD_EXT_MAX_CHUNK_DATA) {
                tcpm_log(port, "Chunk handling not yet supported");
                return;
        }

        switch (type) {
        case PD_EXT_STATUS:
                /*
                 * If PPS related events raised then get PPS status to clear
                 * (see USB PD 3.0 Spec, 6.5.2.4)
                 */
                if (msg->ext_msg.data[USB_PD_EXT_SDB_EVENT_FLAGS] &
                    USB_PD_EXT_SDB_PPS_EVENTS)
                        tcpm_set_state(port, GET_PPS_STATUS_SEND, 0);
                else
                        tcpm_set_state(port, ready_state(port), 0);
                break;
        case PD_EXT_PPS_STATUS:
                /*
                 * For now the PPS status message is used to clear events
                 * and nothing more.
                 */
                tcpm_set_state(port, ready_state(port), 0);
                break;
        case PD_EXT_SOURCE_CAP_EXT:
        case PD_EXT_GET_BATT_CAP:
        case PD_EXT_GET_BATT_STATUS:
        case PD_EXT_BATT_CAP:
        case PD_EXT_GET_MANUFACTURER_INFO:
        case PD_EXT_MANUFACTURER_INFO:
        case PD_EXT_SECURITY_REQUEST:
        case PD_EXT_SECURITY_RESPONSE:
        case PD_EXT_FW_UPDATE_REQUEST:
        case PD_EXT_FW_UPDATE_RESPONSE:
        case PD_EXT_COUNTRY_INFO:
        case PD_EXT_COUNTRY_CODES:
                tcpm_queue_message(port, PD_MSG_CTRL_NOT_SUPP);
                break;
        default:
                tcpm_log(port, "Unhandled extended message type %#x", type);
                break;
        }
}

static void tcpm_pd_rx_handler(struct work_struct *work)
{
        struct pd_rx_event *event = container_of(work,
                                                 struct pd_rx_event, work);
        const struct pd_message *msg = &event->msg;
        unsigned int cnt = pd_header_cnt_le(msg->header);
        struct tcpm_port *port = event->port;

        mutex_lock(&port->lock);

        tcpm_log(port, "PD RX, header: %#x [%d]", le16_to_cpu(msg->header),
                 port->attached);

        if (port->attached) {
                enum pd_ctrl_msg_type type = pd_header_type_le(msg->header);
                unsigned int msgid = pd_header_msgid_le(msg->header);

                /*
                 * USB PD standard, 6.6.1.2:
                 * "... if MessageID value in a received Message is the
                 * same as the stored value, the receiver shall return a
                 * GoodCRC Message with that MessageID value and drop
                 * the Message (this is a retry of an already received
                 * Message). Note: this shall not apply to the Soft_Reset
                 * Message which always has a MessageID value of zero."
                 */
                if (msgid == port->rx_msgid && type != PD_CTRL_SOFT_RESET)
                        goto done;
                port->rx_msgid = msgid;

                /*
                 * If both ends believe to be DFP/host, we have a data role
                 * mismatch.
                 */
                if (!!(le16_to_cpu(msg->header) & PD_HEADER_DATA_ROLE) ==
                    (port->data_role == TYPEC_HOST)) {
                        tcpm_log(port,
                                 "Data role mismatch, initiating error recovery");
                        tcpm_set_state(port, ERROR_RECOVERY, 0);
                } else {
                        if (msg->header & PD_HEADER_EXT_HDR)
                                tcpm_pd_ext_msg_request(port, msg);
                        else if (cnt)
                                tcpm_pd_data_request(port, msg);
                        else
                                tcpm_pd_ctrl_request(port, msg);
                }
        }

done:
        mutex_unlock(&port->lock);
        kfree(event);
}

void tcpm_pd_receive(struct tcpm_port *port, const struct pd_message *msg)
{
        struct pd_rx_event *event;

        event = kzalloc(sizeof(*event), GFP_ATOMIC);
        if (!event)
                return;

        INIT_WORK(&event->work, tcpm_pd_rx_handler);
        event->port = port;
        memcpy(&event->msg, msg, sizeof(*msg));
        queue_work(port->wq, &event->work);
}

EXPORT_SYMBOL_GPL(tcpm_pd_receive);

static int tcpm_pd_send_control(struct tcpm_port *port,
                                enum pd_ctrl_msg_type type)
{
        struct pd_message msg;

        memset(&msg, 0, sizeof(msg));
        msg.header = PD_HEADER_LE(type, port->pwr_role,
                                  port->data_role,
                                  port->negotiated_rev,
                                  port->message_id, 0);

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

/*
 * Send queued message without affecting state.
 * Return true if state machine should go back to sleep,
 * false otherwise.
 */
static bool tcpm_send_queued_message(struct tcpm_port *port)
{
        enum pd_msg_request queued_message;

        do {
                queued_message = port->queued_message;
                port->queued_message = PD_MSG_NONE;

                switch (queued_message) {
                case PD_MSG_CTRL_WAIT:
                        tcpm_pd_send_control(port, PD_CTRL_WAIT);
                        break;
                case PD_MSG_CTRL_REJECT:
                        tcpm_pd_send_control(port, PD_CTRL_REJECT);
                        break;
                case PD_MSG_CTRL_NOT_SUPP:
                        tcpm_pd_send_control(port, PD_CTRL_NOT_SUPP);
                        break;
                case PD_MSG_DATA_SINK_CAP:
                        tcpm_pd_send_sink_caps(port);
                        break;
                case PD_MSG_DATA_SOURCE_CAP:
                        tcpm_pd_send_source_caps(port);
                        break;
                default:
                        break;
                }
        } while (port->queued_message != PD_MSG_NONE);

        if (port->delayed_state != INVALID_STATE) {
                if (time_is_after_jiffies(port->delayed_runtime)) {
                        mod_delayed_work(port->wq, &port->state_machine,
                                         port->delayed_runtime - jiffies);
                        return true;
                }
                port->delayed_state = INVALID_STATE;
        }
        return false;
}

static int tcpm_pd_check_request(struct tcpm_port *port)
{
        u32 pdo, rdo = port->sink_request;
        unsigned int max, op, pdo_max, index;
        enum pd_pdo_type type;

        index = rdo_index(rdo);
        if (!index || index > port->nr_src_pdo)
                return -EINVAL;

        pdo = port->src_pdo[index - 1];
        type = pdo_type(pdo);
        switch (type) {
        case PDO_TYPE_FIXED:
        case PDO_TYPE_VAR:
                max = rdo_max_current(rdo);
                op = rdo_op_current(rdo);
                pdo_max = pdo_max_current(pdo);

                if (op > pdo_max)
                        return -EINVAL;
                if (max > pdo_max && !(rdo & RDO_CAP_MISMATCH))
                        return -EINVAL;

                if (type == PDO_TYPE_FIXED)
                        tcpm_log(port,
                                 "Requested %u mV, %u mA for %u / %u mA",
                                 pdo_fixed_voltage(pdo), pdo_max, op, max);
                else
                        tcpm_log(port,
                                 "Requested %u -> %u mV, %u mA for %u / %u mA",
                                 pdo_min_voltage(pdo), pdo_max_voltage(pdo),
                                 pdo_max, op, max);
                break;
        case PDO_TYPE_BATT:
                max = rdo_max_power(rdo);
                op = rdo_op_power(rdo);
                pdo_max = pdo_max_power(pdo);

                if (op > pdo_max)
                        return -EINVAL;
                if (max > pdo_max && !(rdo & RDO_CAP_MISMATCH))
                        return -EINVAL;
                tcpm_log(port,
                         "Requested %u -> %u mV, %u mW for %u / %u mW",
                         pdo_min_voltage(pdo), pdo_max_voltage(pdo),
                         pdo_max, op, max);
                break;
        default:
                return -EINVAL;
        }

        port->op_vsafe5v = index == 1;

        return 0;
}

#define min_power(x, y) min(pdo_max_power(x), pdo_max_power(y))
#define min_current(x, y) min(pdo_max_current(x), pdo_max_current(y))

static int tcpm_pd_select_pdo(struct tcpm_port *port, int *sink_pdo,
                              int *src_pdo)
{
        unsigned int i, j, max_src_mv = 0, min_src_mv = 0, max_mw = 0,
                     max_mv = 0, src_mw = 0, src_ma = 0, max_snk_mv = 0,
                     min_snk_mv = 0;
        int ret = -EINVAL;

        port->pps_data.supported = false;
        port->usb_type = POWER_SUPPLY_USB_TYPE_PD;

        /*
         * Select the source PDO providing the most power which has a
         * matchig sink cap.
         */
        for (i = 0; i < port->nr_source_caps; i++) {
                u32 pdo = port->source_caps[i];
                enum pd_pdo_type type = pdo_type(pdo);

                switch (type) {
                case PDO_TYPE_FIXED:
                        max_src_mv = pdo_fixed_voltage(pdo);
                        min_src_mv = max_src_mv;
                        break;
                case PDO_TYPE_BATT:
                case PDO_TYPE_VAR:
                        max_src_mv = pdo_max_voltage(pdo);
                        min_src_mv = pdo_min_voltage(pdo);
                        break;
                case PDO_TYPE_APDO:
                        if (pdo_apdo_type(pdo) == APDO_TYPE_PPS) {
                                port->pps_data.supported = true;
                                port->usb_type =
                                        POWER_SUPPLY_USB_TYPE_PD_PPS;
                        }
                        continue;
                default:
                        tcpm_log(port, "Invalid source PDO type, ignoring");
                        continue;
                }

                switch (type) {
                case PDO_TYPE_FIXED:
                case PDO_TYPE_VAR:
                        src_ma = pdo_max_current(pdo);
                        src_mw = src_ma * min_src_mv / 1000;
                        break;
                case PDO_TYPE_BATT:
                        src_mw = pdo_max_power(pdo);
                        break;
                case PDO_TYPE_APDO:
                        continue;
                default:
                        tcpm_log(port, "Invalid source PDO type, ignoring");
                        continue;
                }

                for (j = 0; j < port->nr_snk_pdo; j++) {
                        pdo = port->snk_pdo[j];

                        switch (pdo_type(pdo)) {
                        case PDO_TYPE_FIXED:
                                max_snk_mv = pdo_fixed_voltage(pdo);
                                min_snk_mv = max_snk_mv;
                                break;
                        case PDO_TYPE_BATT:
                        case PDO_TYPE_VAR:
                                max_snk_mv = pdo_max_voltage(pdo);
                                min_snk_mv = pdo_min_voltage(pdo);
                                break;
                        case PDO_TYPE_APDO:
                                continue;
                        default:
                                tcpm_log(port, "Invalid sink PDO type, ignoring");
                                continue;
                        }

                        if (max_src_mv <= max_snk_mv &&
                                min_src_mv >= min_snk_mv) {
                                /* Prefer higher voltages if available */
                                if ((src_mw == max_mw && min_src_mv > max_mv) ||
                                                        src_mw > max_mw) {
                                        *src_pdo = i;
                                        *sink_pdo = j;
                                        max_mw = src_mw;
                                        max_mv = min_src_mv;
                                        ret = 0;
                                }
                        }
                }
        }

        return ret;
}

#define min_pps_apdo_current(x, y)      \
        min(pdo_pps_apdo_max_current(x), pdo_pps_apdo_max_current(y))

static unsigned int tcpm_pd_select_pps_apdo(struct tcpm_port *port)
{
        unsigned int i, j, max_mw = 0, max_mv = 0;
        unsigned int min_src_mv, max_src_mv, src_ma, src_mw;
        unsigned int min_snk_mv, max_snk_mv;
        unsigned int max_op_mv;
        u32 pdo, src, snk;
        unsigned int src_pdo = 0, snk_pdo = 0;

        /*
         * Select the source PPS APDO providing the most power while staying
         * within the board's limits. We skip the first PDO as this is always
         * 5V 3A.
         */
        for (i = 1; i < port->nr_source_caps; ++i) {
                pdo = port->source_caps[i];

                switch (pdo_type(pdo)) {
                case PDO_TYPE_APDO:
                        if (pdo_apdo_type(pdo) != APDO_TYPE_PPS) {
                                tcpm_log(port, "Not PPS APDO (source), ignoring");
                                continue;
                        }

                        min_src_mv = pdo_pps_apdo_min_voltage(pdo);
                        max_src_mv = pdo_pps_apdo_max_voltage(pdo);
                        src_ma = pdo_pps_apdo_max_current(pdo);
                        src_mw = (src_ma * max_src_mv) / 1000;

                        /*
                         * Now search through the sink PDOs to find a matching
                         * PPS APDO. Again skip the first sink PDO as this will
                         * always be 5V 3A.
                         */
                        for (j = 1; j < port->nr_snk_pdo; j++) {
                                pdo = port->snk_pdo[j];

                                switch (pdo_type(pdo)) {
                                case PDO_TYPE_APDO:
                                        if (pdo_apdo_type(pdo) != APDO_TYPE_PPS) {
                                                tcpm_log(port,
                                                         "Not PPS APDO (sink), ignoring");
                                                continue;
                                        }

                                        min_snk_mv =
                                                pdo_pps_apdo_min_voltage(pdo);
                                        max_snk_mv =
                                                pdo_pps_apdo_max_voltage(pdo);
                                        break;
                                default:
                                        tcpm_log(port,
                                                 "Not APDO type (sink), ignoring");
                                        continue;
                                }

                                if (min_src_mv <= max_snk_mv &&
                                    max_src_mv >= min_snk_mv) {
                                        max_op_mv = min(max_src_mv, max_snk_mv);
                                        src_mw = (max_op_mv * src_ma) / 1000;
                                        /* Prefer higher voltages if available */
                                        if ((src_mw == max_mw &&
                                             max_op_mv > max_mv) ||
                                            src_mw > max_mw) {
                                                src_pdo = i;
                                                snk_pdo = j;
                                                max_mw = src_mw;
                                                max_mv = max_op_mv;
                                        }
                                }
                        }

                        break;
                default:
                        tcpm_log(port, "Not APDO type (source), ignoring");
                        continue;
                }
        }

        if (src_pdo) {
                src = port->source_caps[src_pdo];
                snk = port->snk_pdo[snk_pdo];

                port->pps_data.min_volt = max(pdo_pps_apdo_min_voltage(src),
                                              pdo_pps_apdo_min_voltage(snk));
                port->pps_data.max_volt = min(pdo_pps_apdo_max_voltage(src),
                                              pdo_pps_apdo_max_voltage(snk));
                port->pps_data.max_curr = min_pps_apdo_current(src, snk);
                port->pps_data.out_volt = min(port->pps_data.max_volt,
                                              max(port->pps_data.min_volt,
                                                  port->pps_data.out_volt));
                port->pps_data.op_curr = min(port->pps_data.max_curr,
                                             port->pps_data.op_curr);
        }

        return src_pdo;
}

static int tcpm_pd_build_request(struct tcpm_port *port, u32 *rdo)
{
        unsigned int mv, ma, mw, flags;
        unsigned int max_ma, max_mw;
        enum pd_pdo_type type;
        u32 pdo, matching_snk_pdo;
        int src_pdo_index = 0;
        int snk_pdo_index = 0;
        int ret;

        ret = tcpm_pd_select_pdo(port, &snk_pdo_index, &src_pdo_index);
        if (ret < 0)
                return ret;

        pdo = port->source_caps[src_pdo_index];
        matching_snk_pdo = port->snk_pdo[snk_pdo_index];
        type = pdo_type(pdo);

        switch (type) {
        case PDO_TYPE_FIXED:
                mv = pdo_fixed_voltage(pdo);
                break;
        case PDO_TYPE_BATT:
        case PDO_TYPE_VAR:
                mv = pdo_min_voltage(pdo);
                break;
        default:
                tcpm_log(port, "Invalid PDO selected!");
                return -EINVAL;
        }

        /* Select maximum available current within the sink pdo's limit */
        if (type == PDO_TYPE_BATT) {
                mw = min_power(pdo, matching_snk_pdo);
                ma = 1000 * mw / mv;
        } else {
                ma = min_current(pdo, matching_snk_pdo);
                mw = ma * mv / 1000;
        }

        flags = RDO_USB_COMM | RDO_NO_SUSPEND;

        /* Set mismatch bit if offered power is less than operating power */
        max_ma = ma;
        max_mw = mw;
        if (mw < port->operating_snk_mw) {
                flags |= RDO_CAP_MISMATCH;
                if (type == PDO_TYPE_BATT &&
                    (pdo_max_power(matching_snk_pdo) > pdo_max_power(pdo)))
                        max_mw = pdo_max_power(matching_snk_pdo);
                else if (pdo_max_current(matching_snk_pdo) >
                         pdo_max_current(pdo))
                        max_ma = pdo_max_current(matching_snk_pdo);
        }

        tcpm_log(port, "cc=%d cc1=%d cc2=%d vbus=%d vconn=%s polarity=%d",
                 port->cc_req, port->cc1, port->cc2, port->vbus_source,
                 port->vconn_role == TYPEC_SOURCE ? "source" : "sink",
                 port->polarity);

        if (type == PDO_TYPE_BATT) {
                *rdo = RDO_BATT(src_pdo_index + 1, mw, max_mw, flags);

                tcpm_log(port, "Requesting PDO %d: %u mV, %u mW%s",
                         src_pdo_index, mv, mw,
                         flags & RDO_CAP_MISMATCH ? " [mismatch]" : "");
        } else {
                *rdo = RDO_FIXED(src_pdo_index + 1, ma, max_ma, flags);

                tcpm_log(port, "Requesting PDO %d: %u mV, %u mA%s",
                         src_pdo_index, mv, ma,
                         flags & RDO_CAP_MISMATCH ? " [mismatch]" : "");
        }

        port->current_limit = ma;
        port->supply_voltage = mv;

        return 0;
}

static int tcpm_pd_send_request(struct tcpm_port *port)
{
        struct pd_message msg;
        int ret;
        u32 rdo;

        ret = tcpm_pd_build_request(port, &rdo);
        if (ret < 0)
                return ret;

        memset(&msg, 0, sizeof(msg));
        msg.header = PD_HEADER_LE(PD_DATA_REQUEST,
                                  port->pwr_role,
                                  port->data_role,
                                  port->negotiated_rev,
                                  port->message_id, 1);
        msg.payload[0] = cpu_to_le32(rdo);

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

static int tcpm_pd_build_pps_request(struct tcpm_port *port, u32 *rdo)
{
        unsigned int out_mv, op_ma, op_mw, max_mv, max_ma, flags;
        enum pd_pdo_type type;
        unsigned int src_pdo_index;
        u32 pdo;

        src_pdo_index = tcpm_pd_select_pps_apdo(port);
        if (!src_pdo_index)
                return -EOPNOTSUPP;

        pdo = port->source_caps[src_pdo_index];
        type = pdo_type(pdo);

        switch (type) {
        case PDO_TYPE_APDO:
                if (pdo_apdo_type(pdo) != APDO_TYPE_PPS) {
                        tcpm_log(port, "Invalid APDO selected!");
                        return -EINVAL;
                }
                max_mv = port->pps_data.max_volt;
                max_ma = port->pps_data.max_curr;
                out_mv = port->pps_data.out_volt;
                op_ma = port->pps_data.op_curr;
                break;
        default:
                tcpm_log(port, "Invalid PDO selected!");
                return -EINVAL;
        }

        flags = RDO_USB_COMM | RDO_NO_SUSPEND;

        op_mw = (op_ma * out_mv) / 1000;
        if (op_mw < port->operating_snk_mw) {
                /*
                 * Try raising current to meet power needs. If that's not enough
                 * then try upping the voltage. If that's still not enough
                 * then we've obviously chosen a PPS APDO which really isn't
                 * suitable so abandon ship.
                 */
                op_ma = (port->operating_snk_mw * 1000) / out_mv;
                if ((port->operating_snk_mw * 1000) % out_mv)
                        ++op_ma;
                op_ma += RDO_PROG_CURR_MA_STEP - (op_ma % RDO_PROG_CURR_MA_STEP);

                if (op_ma > max_ma) {
                        op_ma = max_ma;
                        out_mv = (port->operating_snk_mw * 1000) / op_ma;
                        if ((port->operating_snk_mw * 1000) % op_ma)
                                ++out_mv;
                        out_mv += RDO_PROG_VOLT_MV_STEP -
                                  (out_mv % RDO_PROG_VOLT_MV_STEP);

                        if (out_mv > max_mv) {
                                tcpm_log(port, "Invalid PPS APDO selected!");
                                return -EINVAL;
                        }
                }
        }

        tcpm_log(port, "cc=%d cc1=%d cc2=%d vbus=%d vconn=%s polarity=%d",
                 port->cc_req, port->cc1, port->cc2, port->vbus_source,
                 port->vconn_role == TYPEC_SOURCE ? "source" : "sink",
                 port->polarity);

        *rdo = RDO_PROG(src_pdo_index + 1, out_mv, op_ma, flags);

        tcpm_log(port, "Requesting APDO %d: %u mV, %u mA",
                 src_pdo_index, out_mv, op_ma);

        port->pps_data.op_curr = op_ma;
        port->pps_data.out_volt = out_mv;

        return 0;
}

static int tcpm_pd_send_pps_request(struct tcpm_port *port)
{
        struct pd_message msg;
        int ret;
        u32 rdo;

        ret = tcpm_pd_build_pps_request(port, &rdo);
        if (ret < 0)
                return ret;

        memset(&msg, 0, sizeof(msg));
        msg.header = PD_HEADER_LE(PD_DATA_REQUEST,
                                  port->pwr_role,
                                  port->data_role,
                                  port->negotiated_rev,
                                  port->message_id, 1);
        msg.payload[0] = cpu_to_le32(rdo);

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

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

        if (enable && port->vbus_charge)
                return -EINVAL;

        tcpm_log(port, "vbus:=%d charge=%d", enable, port->vbus_charge);

        ret = port->tcpc->set_vbus(port->tcpc, enable, port->vbus_charge);
        if (ret < 0)
                return ret;

        port->vbus_source = enable;
        return 0;
}

static int tcpm_set_charge(struct tcpm_port *port, bool charge)
{
        int ret;

        if (charge && port->vbus_source)
                return -EINVAL;

        if (charge != port->vbus_charge) {
                tcpm_log(port, "vbus=%d charge:=%d", port->vbus_source, charge);
                ret = port->tcpc->set_vbus(port->tcpc, port->vbus_source,
                                           charge);
                if (ret < 0)
                        return ret;
        }
        port->vbus_charge = charge;
        return 0;
}

static bool tcpm_start_toggling(struct tcpm_port *port, enum typec_cc_status cc)
{
        int ret;

        if (!port->tcpc->start_toggling)
                return false;

        tcpm_log_force(port, "Start toggling");
        ret = port->tcpc->start_toggling(port->tcpc, port->port_type, cc);
        return ret == 0;
}

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_init_vbus(struct tcpm_port *port)
{
        int ret;

        ret = port->tcpc->set_vbus(port->tcpc, false, false);
        port->vbus_source = false;
        port->vbus_charge = false;
        return ret;
}

static int tcpm_init_vconn(struct tcpm_port *port)
{
        int ret;

        ret = port->tcpc->set_vconn(port->tcpc, false);
        port->vconn_role = TYPEC_SINK;
        return ret;
}

static void tcpm_typec_connect(struct tcpm_port *port)
{
        if (!port->connected) {
                /* Make sure we don't report stale identity information */
                memset(&port->partner_ident, 0, sizeof(port->partner_ident));
                port->partner_desc.usb_pd = port->pd_capable;
                if (tcpm_port_is_debug(port))
                        port->partner_desc.accessory = TYPEC_ACCESSORY_DEBUG;
                else if (tcpm_port_is_audio(port))
                        port->partner_desc.accessory = TYPEC_ACCESSORY_AUDIO;
                else
                        port->partner_desc.accessory = TYPEC_ACCESSORY_NONE;
                port->partner = typec_register_partner(port->typec_port,
                                                       &port->partner_desc);
                port->connected = true;
        }
}

static int tcpm_src_attach(struct tcpm_port *port)
{
        enum typec_cc_polarity polarity =
                                port->cc2 == TYPEC_CC_RD ? TYPEC_POLARITY_CC2
                                                         : TYPEC_POLARITY_CC1;
        int ret;

        if (port->attached)
                return 0;

        ret = tcpm_set_polarity(port, polarity);
        if (ret < 0)
                return ret;

        ret = tcpm_set_roles(port, true, TYPEC_SOURCE, TYPEC_HOST);
        if (ret < 0)
                return ret;

        ret = port->tcpc->set_pd_rx(port->tcpc, true);
        if (ret < 0)
                goto out_disable_mux;

        /*
         * USB Type-C specification, version 1.2,
         * chapter 4.5.2.2.8.1 (Attached.SRC Requirements)
         * Enable VCONN only if the non-RD port is set to RA.
         */
        if ((polarity == TYPEC_POLARITY_CC1 && port->cc2 == TYPEC_CC_RA) ||
            (polarity == TYPEC_POLARITY_CC2 && port->cc1 == TYPEC_CC_RA)) {
                ret = tcpm_set_vconn(port, true);
                if (ret < 0)
                        goto out_disable_pd;
        }

        ret = tcpm_set_vbus(port, true);
        if (ret < 0)
                goto out_disable_vconn;

        port->pd_capable = false;

        port->partner = NULL;

        port->attached = true;
        port->send_discover = true;

        return 0;

out_disable_vconn:
        tcpm_set_vconn(port, false);
out_disable_pd:
        port->tcpc->set_pd_rx(port->tcpc, false);
out_disable_mux:
        tcpm_mux_set(port, TYPEC_STATE_SAFE, USB_ROLE_NONE,
                     TYPEC_ORIENTATION_NONE);
        return ret;
}

static void tcpm_typec_disconnect(struct tcpm_port *port)
{
        if (port->connected) {
                typec_unregister_partner(port->partner);
                port->partner = NULL;
                port->connected = false;
        }
}

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

        for (i = 0; i < modep->altmodes; i++) {
                typec_unregister_altmode(port->partner_altmode[i]);
                port->partner_altmode[i] = NULL;
        }

        memset(modep, 0, sizeof(*modep));
}

static void tcpm_reset_port(struct tcpm_port *port)
{
        tcpm_unregister_altmodes(port);
        tcpm_typec_disconnect(port);
        port->attached = false;
        port->pd_capable = false;
        port->pps_data.supported = false;

        /*
         * First Rx ID should be 0; set this to a sentinel of -1 so that
         * we can check tcpm_pd_rx_handler() if we had seen it before.
         */
        port->rx_msgid = -1;

        port->tcpc->set_pd_rx(port->tcpc, false);
        tcpm_init_vbus(port);   /* also disables charging */
        tcpm_init_vconn(port);
        tcpm_set_current_limit(port, 0, 0);
        tcpm_set_polarity(port, TYPEC_POLARITY_CC1);
        tcpm_mux_set(port, TYPEC_STATE_SAFE, USB_ROLE_NONE,
                     TYPEC_ORIENTATION_NONE);
        tcpm_set_attached_state(port, false);
        port->try_src_count = 0;
        port->try_snk_count = 0;
        port->usb_type = POWER_SUPPLY_USB_TYPE_C;

        power_supply_changed(port->psy);
}

static void tcpm_detach(struct tcpm_port *port)
{
        if (!port->attached)
                return;

        if (tcpm_port_is_disconnected(port))
                port->hard_reset_count = 0;

        tcpm_reset_port(port);
}

static void tcpm_src_detach(struct tcpm_port *port)
{
        tcpm_detach(port);
}

static int tcpm_snk_attach(struct tcpm_port *port)
{
        int ret;

        if (port->attached)
                return 0;

        ret = tcpm_set_polarity(port, port->cc2 != TYPEC_CC_OPEN ?
                                TYPEC_POLARITY_CC2 : TYPEC_POLARITY_CC1);
        if (ret < 0)
                return ret;

        ret = tcpm_set_roles(port, true, TYPEC_SINK, TYPEC_DEVICE);
        if (ret < 0)
                return ret;

        port->pd_capable = false;

        port->partner = NULL;

        port->attached = true;
        port->send_discover = true;

        return 0;
}

static void tcpm_snk_detach(struct tcpm_port *port)
{
        tcpm_detach(port);
}

static int tcpm_acc_attach(struct tcpm_port *port)
{
        int ret;

        if (port->attached)
                return 0;

        ret = tcpm_set_roles(port, true, TYPEC_SOURCE, TYPEC_HOST);
        if (ret < 0)
                return ret;

        port->partner = NULL;

        tcpm_typec_connect(port);

        port->attached = true;

        return 0;
}

static void tcpm_acc_detach(struct tcpm_port *port)
{
        tcpm_detach(port);
}

static inline enum tcpm_state hard_reset_state(struct tcpm_port *port)
{
        if (port->hard_reset_count < PD_N_HARD_RESET_COUNT)
                return HARD_RESET_SEND;
        if (port->pd_capable)
                return ERROR_RECOVERY;
        if (port->pwr_role == TYPEC_SOURCE)
                return SRC_UNATTACHED;
        if (port->state == SNK_WAIT_CAPABILITIES)
                return SNK_READY;
        return SNK_UNATTACHED;
}

static inline enum tcpm_state unattached_state(struct tcpm_port *port)
{
        if (port->port_type == TYPEC_PORT_DRP) {
                if (port->pwr_role == TYPEC_SOURCE)
                        return SRC_UNATTACHED;
                else
                        return SNK_UNATTACHED;
        } else if (port->port_type == TYPEC_PORT_SRC) {
                return SRC_UNATTACHED;
        }

        return SNK_UNATTACHED;
}

static void tcpm_check_send_discover(struct tcpm_port *port)
{
        if (port->data_role == TYPEC_HOST && port->send_discover &&
            port->pd_capable) {
                tcpm_send_vdm(port, USB_SID_PD, CMD_DISCOVER_IDENT, NULL, 0);
                port->send_discover = false;
        }
}

static void tcpm_swap_complete(struct tcpm_port *port, int result)
{
        if (port->swap_pending) {
                port->swap_status = result;
                port->swap_pending = false;
                port->non_pd_role_swap = false;
                complete(&port->swap_complete);
        }
}

static enum typec_pwr_opmode tcpm_get_pwr_opmode(enum typec_cc_status cc)
{
        switch (cc) {
        case TYPEC_CC_RP_1_5:
                return TYPEC_PWR_MODE_1_5A;
        case TYPEC_CC_RP_3_0:
                return TYPEC_PWR_MODE_3_0A;
        case TYPEC_CC_RP_DEF:
        default:
                return TYPEC_PWR_MODE_USB;
        }
}

static void run_state_machine(struct tcpm_port *port)
{
        int ret;
        enum typec_pwr_opmode opmode;
        unsigned int msecs;

        port->enter_state = port->state;
        switch (port->state) {
        case TOGGLING:
                break;
        /* SRC states */
        case SRC_UNATTACHED:
                if (!port->non_pd_role_swap)
                        tcpm_swap_complete(port, -ENOTCONN);
                tcpm_src_detach(port);
                if (tcpm_start_toggling(port, tcpm_rp_cc(port))) {
                        tcpm_set_state(port, TOGGLING, 0);
                        break;
                }
                tcpm_set_cc(port, tcpm_rp_cc(port));
                if (port->port_type == TYPEC_PORT_DRP)
                        tcpm_set_state(port, SNK_UNATTACHED, PD_T_DRP_SNK);
                break;
        case SRC_ATTACH_WAIT:
                if (tcpm_port_is_debug(port))
                        tcpm_set_state(port, DEBUG_ACC_ATTACHED,
                                       PD_T_CC_DEBOUNCE);
                else if (tcpm_port_is_audio(port))
                        tcpm_set_state(port, AUDIO_ACC_ATTACHED,
                                       PD_T_CC_DEBOUNCE);
                else if (tcpm_port_is_source(port))
                        tcpm_set_state(port,
                                       tcpm_try_snk(port) ? SNK_TRY
                                                          : SRC_ATTACHED,
                                       PD_T_CC_DEBOUNCE);
                break;

        case SNK_TRY:
                port->try_snk_count++;
                /*
                 * Requirements:
                 * - Do not drive vconn or vbus
                 * - Terminate CC pins (both) to Rd
                 * Action:
                 * - Wait for tDRPTry (PD_T_DRP_TRY).
                 *   Until then, ignore any state changes.
                 */
                tcpm_set_cc(port, TYPEC_CC_RD);
                tcpm_set_state(port, SNK_TRY_WAIT, PD_T_DRP_TRY);
                break;
        case SNK_TRY_WAIT:
                if (tcpm_port_is_sink(port)) {
                        tcpm_set_state(port, SNK_TRY_WAIT_DEBOUNCE, 0);
                } else {
                        tcpm_set_state(port, SRC_TRYWAIT, 0);
                        port->max_wait = 0;
                }
                break;
        case SNK_TRY_WAIT_DEBOUNCE:
                tcpm_set_state(port, SNK_TRY_WAIT_DEBOUNCE_CHECK_VBUS,
                               PD_T_PD_DEBOUNCE);
                break;
        case SNK_TRY_WAIT_DEBOUNCE_CHECK_VBUS:
                if (port->vbus_present && tcpm_port_is_sink(port)) {
                        tcpm_set_state(port, SNK_ATTACHED, 0);
                } else {
                        tcpm_set_state(port, SRC_TRYWAIT, 0);
                        port->max_wait = 0;
                }
                break;
        case SRC_TRYWAIT:
                tcpm_set_cc(port, tcpm_rp_cc(port));
                if (port->max_wait == 0) {
                        port->max_wait = jiffies +
                                         msecs_to_jiffies(PD_T_DRP_TRY);
                        tcpm_set_state(port, SRC_TRYWAIT_UNATTACHED,
                                       PD_T_DRP_TRY);
                } else {
                        if (time_is_after_jiffies(port->max_wait))
                                tcpm_set_state(port, SRC_TRYWAIT_UNATTACHED,
                                               jiffies_to_msecs(port->max_wait -
                                                                jiffies));
                        else
                                tcpm_set_state(port, SNK_UNATTACHED, 0);
                }
                break;
        case SRC_TRYWAIT_DEBOUNCE:
                tcpm_set_state(port, SRC_ATTACHED, PD_T_CC_DEBOUNCE);
                break;
        case SRC_TRYWAIT_UNATTACHED:
                tcpm_set_state(port, SNK_UNATTACHED, 0);
                break;

        case SRC_ATTACHED:
                ret = tcpm_src_attach(port);
                tcpm_set_state(port, SRC_UNATTACHED,
                               ret < 0 ? 0 : PD_T_PS_SOURCE_ON);
                break;
        case SRC_STARTUP:
                opmode =  tcpm_get_pwr_opmode(tcpm_rp_cc(port));
                typec_set_pwr_opmode(port->typec_port, opmode);
                port->pwr_opmode = TYPEC_PWR_MODE_USB;
                port->caps_count = 0;
                port->negotiated_rev = PD_MAX_REV;
                port->message_id = 0;
                port->rx_msgid = -1;
                port->explicit_contract = false;
                tcpm_set_state(port, SRC_SEND_CAPABILITIES, 0);
                break;
        case SRC_SEND_CAPABILITIES:
                port->caps_count++;
                if (port->caps_count > PD_N_CAPS_COUNT) {
                        tcpm_set_state(port, SRC_READY, 0);
                        break;
                }
                ret = tcpm_pd_send_source_caps(port);
                if (ret < 0) {
                        tcpm_set_state(port, SRC_SEND_CAPABILITIES,
                                       PD_T_SEND_SOURCE_CAP);
                } else {
                        /*
                         * Per standard, we should clear the reset counter here.
                         * However, that can result in state machine hang-ups.
                         * Reset it only in READY state to improve stability.
                         */
                        /* port->hard_reset_count = 0; */
                        port->caps_count = 0;
                        port->pd_capable = true;
                        tcpm_set_state_cond(port, SRC_SEND_CAPABILITIES_TIMEOUT,
                                            PD_T_SEND_SOURCE_CAP);
                }
                break;
        case SRC_SEND_CAPABILITIES_TIMEOUT:
                /*
                 * Error recovery for a PD_DATA_SOURCE_CAP reply timeout.
                 *
                 * PD 2.0 sinks are supposed to accept src-capabilities with a
                 * 3.0 header and simply ignore any src PDOs which the sink does
                 * not understand such as PPS but some 2.0 sinks instead ignore
                 * the entire PD_DATA_SOURCE_CAP message, causing contract
                 * negotiation to fail.
                 *
                 * After PD_N_HARD_RESET_COUNT hard-reset attempts, we try
                 * sending src-capabilities with a lower PD revision to
                 * make these broken sinks work.
                 */
                if (port->hard_reset_count < PD_N_HARD_RESET_COUNT) {
                        tcpm_set_state(port, HARD_RESET_SEND, 0);
                } else if (port->negotiated_rev > PD_REV20) {
                        port->negotiated_rev--;
                        port->hard_reset_count = 0;
                        tcpm_set_state(port, SRC_SEND_CAPABILITIES, 0);
                } else {
                        tcpm_set_state(port, hard_reset_state(port), 0);
                }