// SPDX-License-Identifier: GPL-2.0+
/*
 * Copyright 2015-2017 Google, Inc
 *
 * USB Type-C Port Controller Interface.
 */

#include <linux/delay.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/interrupt.h>
#include <linux/property.h>
#include <linux/regmap.h>
#include <linux/usb/pd.h>
#include <linux/usb/tcpm.h>
#include <linux/usb/typec.h>

#include "tcpci.h"

#define PD_RETRY_COUNT_DEFAULT                  3
#define PD_RETRY_COUNT_3_0_OR_HIGHER            2
#define AUTO_DISCHARGE_DEFAULT_THRESHOLD_MV     3500
#define VSINKPD_MIN_IR_DROP_MV                  750
#define VSRC_NEW_MIN_PERCENT                    95
#define VSRC_VALID_MIN_MV                       500
#define VPPS_NEW_MIN_PERCENT                    95
#define VPPS_VALID_MIN_MV                       100
#define VSINKDISCONNECT_PD_MIN_PERCENT          90

#define tcpc_presenting_rd(reg, cc) \
        (!(TCPC_ROLE_CTRL_DRP & (reg)) && \
         (((reg) & (TCPC_ROLE_CTRL_## cc ##_MASK << TCPC_ROLE_CTRL_## cc ##_SHIFT)) == \
          (TCPC_ROLE_CTRL_CC_RD << TCPC_ROLE_CTRL_## cc ##_SHIFT)))

struct tcpci {
        struct device *dev;

        struct tcpm_port *port;

        struct regmap *regmap;

        bool controls_vbus;

        struct tcpc_dev tcpc;
        struct tcpci_data *data;
};

struct tcpci_chip {
        struct tcpci *tcpci;
        struct tcpci_data data;
};

struct tcpm_port *tcpci_get_tcpm_port(struct tcpci *tcpci)
{
        return tcpci->port;
}
EXPORT_SYMBOL_GPL(tcpci_get_tcpm_port);

static inline struct tcpci *tcpc_to_tcpci(struct tcpc_dev *tcpc)
{
        return container_of(tcpc, struct tcpci, tcpc);
}

static int tcpci_read16(struct tcpci *tcpci, unsigned int reg, u16 *val)
{
        return regmap_raw_read(tcpci->regmap, reg, val, sizeof(u16));
}

static int tcpci_write16(struct tcpci *tcpci, unsigned int reg, u16 val)
{
        return regmap_raw_write(tcpci->regmap, reg, &val, sizeof(u16));
}

static int tcpci_set_cc(struct tcpc_dev *tcpc, enum typec_cc_status cc)
{
        struct tcpci *tcpci = tcpc_to_tcpci(tcpc);
        unsigned int reg;
        int ret;

        switch (cc) {
        case TYPEC_CC_RA:
                reg = (TCPC_ROLE_CTRL_CC_RA << TCPC_ROLE_CTRL_CC1_SHIFT) |
                        (TCPC_ROLE_CTRL_CC_RA << TCPC_ROLE_CTRL_CC2_SHIFT);
                break;
        case TYPEC_CC_RD:
                reg = (TCPC_ROLE_CTRL_CC_RD << TCPC_ROLE_CTRL_CC1_SHIFT) |
                        (TCPC_ROLE_CTRL_CC_RD << TCPC_ROLE_CTRL_CC2_SHIFT);
                break;
        case TYPEC_CC_RP_DEF:
                reg = (TCPC_ROLE_CTRL_CC_RP << TCPC_ROLE_CTRL_CC1_SHIFT) |
                        (TCPC_ROLE_CTRL_CC_RP << TCPC_ROLE_CTRL_CC2_SHIFT) |
                        (TCPC_ROLE_CTRL_RP_VAL_DEF <<
                         TCPC_ROLE_CTRL_RP_VAL_SHIFT);
                break;
        case TYPEC_CC_RP_1_5:
                reg = (TCPC_ROLE_CTRL_CC_RP << TCPC_ROLE_CTRL_CC1_SHIFT) |
                        (TCPC_ROLE_CTRL_CC_RP << TCPC_ROLE_CTRL_CC2_SHIFT) |
                        (TCPC_ROLE_CTRL_RP_VAL_1_5 <<
                         TCPC_ROLE_CTRL_RP_VAL_SHIFT);
                break;
        case TYPEC_CC_RP_3_0:
                reg = (TCPC_ROLE_CTRL_CC_RP << TCPC_ROLE_CTRL_CC1_SHIFT) |
                        (TCPC_ROLE_CTRL_CC_RP << TCPC_ROLE_CTRL_CC2_SHIFT) |
                        (TCPC_ROLE_CTRL_RP_VAL_3_0 <<
                         TCPC_ROLE_CTRL_RP_VAL_SHIFT);
                break;
        case TYPEC_CC_OPEN:
        default:
                reg = (TCPC_ROLE_CTRL_CC_OPEN << TCPC_ROLE_CTRL_CC1_SHIFT) |
                        (TCPC_ROLE_CTRL_CC_OPEN << TCPC_ROLE_CTRL_CC2_SHIFT);
                break;
        }

        ret = regmap_write(tcpci->regmap, TCPC_ROLE_CTRL, reg);
        if (ret < 0)
                return ret;

        return 0;
}

static int tcpci_apply_rc(struct tcpc_dev *tcpc, enum typec_cc_status cc,
                          enum typec_cc_polarity polarity)
{
        struct tcpci *tcpci = tcpc_to_tcpci(tcpc);
        unsigned int reg;
        int ret;

        ret = regmap_read(tcpci->regmap, TCPC_ROLE_CTRL, &reg);
        if (ret < 0)
                return ret;

        /*
         * APPLY_RC state is when ROLE_CONTROL.CC1 != ROLE_CONTROL.CC2 and vbus autodischarge on
         * disconnect is disabled. Bail out when ROLE_CONTROL.CC1 != ROLE_CONTROL.CC2.
         */
        if (((reg & (TCPC_ROLE_CTRL_CC2_MASK << TCPC_ROLE_CTRL_CC2_SHIFT)) >>
             TCPC_ROLE_CTRL_CC2_SHIFT) !=
            ((reg & (TCPC_ROLE_CTRL_CC1_MASK << TCPC_ROLE_CTRL_CC1_SHIFT)) >>
             TCPC_ROLE_CTRL_CC1_SHIFT))
                return 0;

        return regmap_update_bits(tcpci->regmap, TCPC_ROLE_CTRL, polarity == TYPEC_POLARITY_CC1 ?
                                  TCPC_ROLE_CTRL_CC2_MASK << TCPC_ROLE_CTRL_CC2_SHIFT :
                                  TCPC_ROLE_CTRL_CC1_MASK << TCPC_ROLE_CTRL_CC1_SHIFT,
                                  TCPC_ROLE_CTRL_CC_OPEN);
}

static int tcpci_start_toggling(struct tcpc_dev *tcpc,
                                enum typec_port_type port_type,
                                enum typec_cc_status cc)
{
        int ret;
        struct tcpci *tcpci = tcpc_to_tcpci(tcpc);
        unsigned int reg = TCPC_ROLE_CTRL_DRP;

        if (port_type != TYPEC_PORT_DRP)
                return -EOPNOTSUPP;

        /* Handle vendor drp toggling */
        if (tcpci->data->start_drp_toggling) {
                ret = tcpci->data->start_drp_toggling(tcpci, tcpci->data, cc);
                if (ret < 0)
                        return ret;
        }

        switch (cc) {
        default:
        case TYPEC_CC_RP_DEF:
                reg |= (TCPC_ROLE_CTRL_RP_VAL_DEF <<
                        TCPC_ROLE_CTRL_RP_VAL_SHIFT);
                break;
        case TYPEC_CC_RP_1_5:
                reg |= (TCPC_ROLE_CTRL_RP_VAL_1_5 <<
                        TCPC_ROLE_CTRL_RP_VAL_SHIFT);
                break;
        case TYPEC_CC_RP_3_0:
                reg |= (TCPC_ROLE_CTRL_RP_VAL_3_0 <<
                        TCPC_ROLE_CTRL_RP_VAL_SHIFT);
                break;
        }

        if (cc == TYPEC_CC_RD)
                reg |= (TCPC_ROLE_CTRL_CC_RD << TCPC_ROLE_CTRL_CC1_SHIFT) |
                           (TCPC_ROLE_CTRL_CC_RD << TCPC_ROLE_CTRL_CC2_SHIFT);
        else
                reg |= (TCPC_ROLE_CTRL_CC_RP << TCPC_ROLE_CTRL_CC1_SHIFT) |
                           (TCPC_ROLE_CTRL_CC_RP << TCPC_ROLE_CTRL_CC2_SHIFT);
        ret = regmap_write(tcpci->regmap, TCPC_ROLE_CTRL, reg);
        if (ret < 0)
                return ret;
        return regmap_write(tcpci->regmap, TCPC_COMMAND,
                            TCPC_CMD_LOOK4CONNECTION);
}

static enum typec_cc_status tcpci_to_typec_cc(unsigned int cc, bool sink)
{
        switch (cc) {
        case 0x1:
                return sink ? TYPEC_CC_RP_DEF : TYPEC_CC_RA;
        case 0x2:
                return sink ? TYPEC_CC_RP_1_5 : TYPEC_CC_RD;
        case 0x3:
                if (sink)
                        return TYPEC_CC_RP_3_0;
                fallthrough;
        case 0x0:
        default:
                return TYPEC_CC_OPEN;
        }
}

static int tcpci_get_cc(struct tcpc_dev *tcpc,
                        enum typec_cc_status *cc1, enum typec_cc_status *cc2)
{
        struct tcpci *tcpci = tcpc_to_tcpci(tcpc);
        unsigned int reg, role_control;
        int ret;

        ret = regmap_read(tcpci->regmap, TCPC_ROLE_CTRL, &role_control);
        if (ret < 0)
                return ret;

        ret = regmap_read(tcpci->regmap, TCPC_CC_STATUS, &reg);
        if (ret < 0)
                return ret;

        *cc1 = tcpci_to_typec_cc((reg >> TCPC_CC_STATUS_CC1_SHIFT) &
                                 TCPC_CC_STATUS_CC1_MASK,
                                 reg & TCPC_CC_STATUS_TERM ||
                                 tcpc_presenting_rd(role_control, CC1));
        *cc2 = tcpci_to_typec_cc((reg >> TCPC_CC_STATUS_CC2_SHIFT) &
                                 TCPC_CC_STATUS_CC2_MASK,
                                 reg & TCPC_CC_STATUS_TERM ||
                                 tcpc_presenting_rd(role_control, CC2));

        return 0;
}

static int tcpci_set_polarity(struct tcpc_dev *tcpc,
                              enum typec_cc_polarity polarity)
{
        struct tcpci *tcpci = tcpc_to_tcpci(tcpc);
        unsigned int reg;
        int ret;
        enum typec_cc_status cc1, cc2;

        /* Obtain Rp setting from role control */
        ret = regmap_read(tcpci->regmap, TCPC_ROLE_CTRL, &reg);
        if (ret < 0)
                return ret;

        ret = tcpci_get_cc(tcpc, &cc1, &cc2);
        if (ret < 0)
                return ret;

        /*
         * When port has drp toggling enabled, ROLE_CONTROL would only have the initial
         * terminations for the toggling and does not indicate the final cc
         * terminations when ConnectionResult is 0 i.e. drp toggling stops and
         * the connection is resolbed. Infer port role from TCPC_CC_STATUS based on the
         * terminations seen. The port role is then used to set the cc terminations.
         */
        if (reg & TCPC_ROLE_CTRL_DRP) {
                /* Disable DRP for the OPEN setting to take effect */
                reg = reg & ~TCPC_ROLE_CTRL_DRP;

                if (polarity == TYPEC_POLARITY_CC2) {
                        reg &= ~(TCPC_ROLE_CTRL_CC2_MASK << TCPC_ROLE_CTRL_CC2_SHIFT);
                        /* Local port is source */
                        if (cc2 == TYPEC_CC_RD)
                                /* Role control would have the Rp setting when DRP was enabled */
                                reg |= TCPC_ROLE_CTRL_CC_RP << TCPC_ROLE_CTRL_CC2_SHIFT;
                        else
                                reg |= TCPC_ROLE_CTRL_CC_RD << TCPC_ROLE_CTRL_CC2_SHIFT;
                } else {
                        reg &= ~(TCPC_ROLE_CTRL_CC1_MASK << TCPC_ROLE_CTRL_CC1_SHIFT);
                        /* Local port is source */
                        if (cc1 == TYPEC_CC_RD)
                                /* Role control would have the Rp setting when DRP was enabled */
                                reg |= TCPC_ROLE_CTRL_CC_RP << TCPC_ROLE_CTRL_CC1_SHIFT;
                        else
                                reg |= TCPC_ROLE_CTRL_CC_RD << TCPC_ROLE_CTRL_CC1_SHIFT;
                }
        }

        if (polarity == TYPEC_POLARITY_CC2)
                reg |= TCPC_ROLE_CTRL_CC_OPEN << TCPC_ROLE_CTRL_CC1_SHIFT;
        else
                reg |= TCPC_ROLE_CTRL_CC_OPEN << TCPC_ROLE_CTRL_CC2_SHIFT;
        ret = regmap_write(tcpci->regmap, TCPC_ROLE_CTRL, reg);
        if (ret < 0)
                return ret;

        return regmap_write(tcpci->regmap, TCPC_TCPC_CTRL,
                           (polarity == TYPEC_POLARITY_CC2) ?
                           TCPC_TCPC_CTRL_ORIENTATION : 0);
}

static void tcpci_set_partner_usb_comm_capable(struct tcpc_dev *tcpc, bool capable)
{
        struct tcpci *tcpci = tcpc_to_tcpci(tcpc);

        if (tcpci->data->set_partner_usb_comm_capable)
                tcpci->data->set_partner_usb_comm_capable(tcpci, tcpci->data, capable);
}

static int tcpci_set_vconn(struct tcpc_dev *tcpc, bool enable)
{
        struct tcpci *tcpci = tcpc_to_tcpci(tcpc);
        int ret;

        /* Handle vendor set vconn */
        if (tcpci->data->set_vconn) {
                ret = tcpci->data->set_vconn(tcpci, tcpci->data, enable);
                if (ret < 0)
                        return ret;
        }

        return regmap_update_bits(tcpci->regmap, TCPC_POWER_CTRL,
                                TCPC_POWER_CTRL_VCONN_ENABLE,
                                enable ? TCPC_POWER_CTRL_VCONN_ENABLE : 0);
}

static int tcpci_enable_auto_vbus_discharge(struct tcpc_dev *dev, bool enable)
{
        struct tcpci *tcpci = tcpc_to_tcpci(dev);
        int ret;

        ret = regmap_update_bits(tcpci->regmap, TCPC_POWER_CTRL, TCPC_POWER_CTRL_AUTO_DISCHARGE,
                                 enable ? TCPC_POWER_CTRL_AUTO_DISCHARGE : 0);
        return ret;
}

static int tcpci_set_auto_vbus_discharge_threshold(struct tcpc_dev *dev, enum typec_pwr_opmode mode,
                                                   bool pps_active, u32 requested_vbus_voltage_mv)
{
        struct tcpci *tcpci = tcpc_to_tcpci(dev);
        unsigned int pwr_ctrl, threshold = 0;
        int ret;

        /*
         * Indicates that vbus is going to go away due PR_SWAP, hard reset etc.
         * Do not discharge vbus here.
         */
        if (requested_vbus_voltage_mv == 0)
                goto write_thresh;

        ret = regmap_read(tcpci->regmap, TCPC_POWER_CTRL, &pwr_ctrl);
        if (ret < 0)
                return ret;

        if (pwr_ctrl & TCPC_FAST_ROLE_SWAP_EN) {
                /* To prevent disconnect when the source is fast role swap is capable. */
                threshold = AUTO_DISCHARGE_DEFAULT_THRESHOLD_MV;
        } else if (mode == TYPEC_PWR_MODE_PD) {
                if (pps_active)
                        threshold = ((VPPS_NEW_MIN_PERCENT * requested_vbus_voltage_mv / 100) -
                                     VSINKPD_MIN_IR_DROP_MV - VPPS_VALID_MIN_MV) *
                                     VSINKDISCONNECT_PD_MIN_PERCENT / 100;
                else
                        threshold = ((VSRC_NEW_MIN_PERCENT * requested_vbus_voltage_mv / 100) -
                                     VSINKPD_MIN_IR_DROP_MV - VSRC_VALID_MIN_MV) *
                                     VSINKDISCONNECT_PD_MIN_PERCENT / 100;
        } else {
                /* 3.5V for non-pd sink */
                threshold = AUTO_DISCHARGE_DEFAULT_THRESHOLD_MV;
        }

        threshold = threshold / TCPC_VBUS_SINK_DISCONNECT_THRESH_LSB_MV;

        if (threshold > TCPC_VBUS_SINK_DISCONNECT_THRESH_MAX)
                return -EINVAL;

write_thresh:
        return tcpci_write16(tcpci, TCPC_VBUS_SINK_DISCONNECT_THRESH, threshold);
}

static int tcpci_enable_frs(struct tcpc_dev *dev, bool enable)
{
        struct tcpci *tcpci = tcpc_to_tcpci(dev);
        int ret;

        /* To prevent disconnect during FRS, set disconnect threshold to 3.5V */
        ret = tcpci_write16(tcpci, TCPC_VBUS_SINK_DISCONNECT_THRESH, enable ? 0 : 0x8c);
        if (ret < 0)
                return ret;

        ret = regmap_update_bits(tcpci->regmap, TCPC_POWER_CTRL, TCPC_FAST_ROLE_SWAP_EN, enable ?
                                 TCPC_FAST_ROLE_SWAP_EN : 0);

        return ret;
}

static void tcpci_frs_sourcing_vbus(struct tcpc_dev *dev)
{
        struct tcpci *tcpci = tcpc_to_tcpci(dev);

        if (tcpci->data->frs_sourcing_vbus)
                tcpci->data->frs_sourcing_vbus(tcpci, tcpci->data);
}

static int tcpci_set_bist_data(struct tcpc_dev *tcpc, bool enable)
{
        struct tcpci *tcpci = tcpc_to_tcpci(tcpc);

        return regmap_update_bits(tcpci->regmap, TCPC_TCPC_CTRL, TCPC_TCPC_CTRL_BIST_TM,
                                 enable ? TCPC_TCPC_CTRL_BIST_TM : 0);
}

static int tcpci_set_roles(struct tcpc_dev *tcpc, bool attached,
                           enum typec_role role, enum typec_data_role data)
{
        struct tcpci *tcpci = tcpc_to_tcpci(tcpc);
        unsigned int reg;
        int ret;

        reg = PD_REV20 << TCPC_MSG_HDR_INFO_REV_SHIFT;
        if (role == TYPEC_SOURCE)
                reg |= TCPC_MSG_HDR_INFO_PWR_ROLE;
        if (data == TYPEC_HOST)
                reg |= TCPC_MSG_HDR_INFO_DATA_ROLE;
        ret = regmap_write(tcpci->regmap, TCPC_MSG_HDR_INFO, reg);
        if (ret < 0)
                return ret;

        return 0;
}

static int tcpci_set_pd_rx(struct tcpc_dev *tcpc, bool enable)
{
        struct tcpci *tcpci = tcpc_to_tcpci(tcpc);
        unsigned int reg = 0;
        int ret;

        if (enable)
                reg = TCPC_RX_DETECT_SOP | TCPC_RX_DETECT_HARD_RESET;
        ret = regmap_write(tcpci->regmap, TCPC_RX_DETECT, reg);
        if (ret < 0)
                return ret;

        return 0;
}

static int tcpci_get_vbus(struct tcpc_dev *tcpc)
{
        struct tcpci *tcpci = tcpc_to_tcpci(tcpc);
        unsigned int reg;
        int ret;

        ret = regmap_read(tcpci->regmap, TCPC_POWER_STATUS, &reg);
        if (ret < 0)
                return ret;

        return !!(reg & TCPC_POWER_STATUS_VBUS_PRES);
}

static bool tcpci_is_vbus_vsafe0v(struct tcpc_dev *tcpc)
{
        struct tcpci *tcpci = tcpc_to_tcpci(tcpc);
        unsigned int reg;
        int ret;

        ret = regmap_read(tcpci->regmap, TCPC_EXTENDED_STATUS, &reg);
        if (ret < 0)
                return false;

        return !!(reg & TCPC_EXTENDED_STATUS_VSAFE0V);
}

static int tcpci_set_vbus(struct tcpc_dev *tcpc, bool source, bool sink)
{
        struct tcpci *tcpci = tcpc_to_tcpci(tcpc);
        int ret;

        if (tcpci->data->set_vbus) {
                ret = tcpci->data->set_vbus(tcpci, tcpci->data, source, sink);
                /* Bypass when ret > 0 */
                if (ret != 0)
                        return ret < 0 ? ret : 0;
        }

        /* Disable both source and sink first before enabling anything */

        if (!source) {
                ret = regmap_write(tcpci->regmap, TCPC_COMMAND,
                                   TCPC_CMD_DISABLE_SRC_VBUS);
                if (ret < 0)
                        return ret;
        }

        if (!sink) {
                ret = regmap_write(tcpci->regmap, TCPC_COMMAND,
                                   TCPC_CMD_DISABLE_SINK_VBUS);
                if (ret < 0)
                        return ret;
        }

        if (source) {
                ret = regmap_write(tcpci->regmap, TCPC_COMMAND,
                                   TCPC_CMD_SRC_VBUS_DEFAULT);
                if (ret < 0)
                        return ret;
        }

        if (sink) {
                ret = regmap_write(tcpci->regmap, TCPC_COMMAND,
                                   TCPC_CMD_SINK_VBUS);
                if (ret < 0)
                        return ret;
        }

        return 0;
}

static int tcpci_pd_transmit(struct tcpc_dev *tcpc, enum tcpm_transmit_type type,
                             const struct pd_message *msg, unsigned int negotiated_rev)
{
        struct tcpci *tcpci = tcpc_to_tcpci(tcpc);
        u16 header = msg ? le16_to_cpu(msg->header) : 0;
        unsigned int reg, cnt;
        int ret;

        cnt = msg ? pd_header_cnt(header) * 4 : 0;
        /**
         * TCPCI spec forbids direct access of TCPC_TX_DATA.
         * But, since some of the chipsets offer this capability,
         * it's fair to support both.
         */
        if (tcpci->data->TX_BUF_BYTE_x_hidden) {
                u8 buf[TCPC_TRANSMIT_BUFFER_MAX_LEN] = {0,};
                u8 pos = 0;

                /* Payload + header + TCPC_TX_BYTE_CNT */
                buf[pos++] = cnt + 2;

                if (msg)
                        memcpy(&buf[pos], &msg->header, sizeof(msg->header));

                pos += sizeof(header);

                if (cnt > 0)
                        memcpy(&buf[pos], msg->payload, cnt);

                pos += cnt;
                ret = regmap_raw_write(tcpci->regmap, TCPC_TX_BYTE_CNT, buf, pos);
                if (ret < 0)
                        return ret;
        } else {
                ret = regmap_write(tcpci->regmap, TCPC_TX_BYTE_CNT, cnt + 2);
                if (ret < 0)
                        return ret;

                ret = tcpci_write16(tcpci, TCPC_TX_HDR, header);
                if (ret < 0)
                        return ret;

                if (cnt > 0) {
                        ret = regmap_raw_write(tcpci->regmap, TCPC_TX_DATA, &msg->payload, cnt);
                        if (ret < 0)
                                return ret;
                }
        }

        /* nRetryCount is 3 in PD2.0 spec where 2 in PD3.0 spec */
        reg = ((negotiated_rev > PD_REV20 ? PD_RETRY_COUNT_3_0_OR_HIGHER : PD_RETRY_COUNT_DEFAULT)
               << TCPC_TRANSMIT_RETRY_SHIFT) | (type << TCPC_TRANSMIT_TYPE_SHIFT);
        ret = regmap_write(tcpci->regmap, TCPC_TRANSMIT, reg);
        if (ret < 0)
                return ret;

        return 0;
}

static int tcpci_init(struct tcpc_dev *tcpc)
{
        struct tcpci *tcpci = tcpc_to_tcpci(tcpc);
        unsigned long timeout = jiffies + msecs_to_jiffies(2000); /* XXX */
        unsigned int reg;
        int ret;

        while (time_before_eq(jiffies, timeout)) {
                ret = regmap_read(tcpci->regmap, TCPC_POWER_STATUS, &reg);
                if (ret < 0)
                        return ret;
                if (!(reg & TCPC_POWER_STATUS_UNINIT))
                        break;
                usleep_range(10000, 20000);
        }
        if (time_after(jiffies, timeout))
                return -ETIMEDOUT;

        /* Handle vendor init */
        if (tcpci->data->init) {
                ret = tcpci->data->init(tcpci, tcpci->data);
                if (ret < 0)
                        return ret;
        }

        /* Clear all events */
        ret = tcpci_write16(tcpci, TCPC_ALERT, 0xffff);
        if (ret < 0)
                return ret;

        if (tcpci->controls_vbus)
                reg = TCPC_POWER_STATUS_VBUS_PRES;
        else
                reg = 0;
        ret = regmap_write(tcpci->regmap, TCPC_POWER_STATUS_MASK, reg);
        if (ret < 0)
                return ret;

        /* Enable Vbus detection */
        ret = regmap_write(tcpci->regmap, TCPC_COMMAND,
                           TCPC_CMD_ENABLE_VBUS_DETECT);
        if (ret < 0)
                return ret;

        reg = TCPC_ALERT_TX_SUCCESS | TCPC_ALERT_TX_FAILED |
                TCPC_ALERT_TX_DISCARDED | TCPC_ALERT_RX_STATUS |
                TCPC_ALERT_RX_HARD_RST | TCPC_ALERT_CC_STATUS;
        if (tcpci->controls_vbus)
                reg |= TCPC_ALERT_POWER_STATUS;
        /* Enable VSAFE0V status interrupt when detecting VSAFE0V is supported */
        if (tcpci->data->vbus_vsafe0v) {
                reg |= TCPC_ALERT_EXTENDED_STATUS;
                ret = regmap_write(tcpci->regmap, TCPC_EXTENDED_STATUS_MASK,
                                   TCPC_EXTENDED_STATUS_VSAFE0V);
                if (ret < 0)
                        return ret;
        }
        return tcpci_write16(tcpci, TCPC_ALERT_MASK, reg);
}

irqreturn_t tcpci_irq(struct tcpci *tcpci)
{
        u16 status;
        int ret;
        unsigned int raw;

        tcpci_read16(tcpci, TCPC_ALERT, &status);

        /*
         * Clear alert status for everything except RX_STATUS, which shouldn't
         * be cleared until we have successfully retrieved message.
         */
        if (status & ~TCPC_ALERT_RX_STATUS)
                tcpci_write16(tcpci, TCPC_ALERT,
                              status & ~TCPC_ALERT_RX_STATUS);

        if (status & TCPC_ALERT_CC_STATUS)
                tcpm_cc_change(tcpci->port);

        if (status & TCPC_ALERT_POWER_STATUS) {
                regmap_read(tcpci->regmap, TCPC_POWER_STATUS_MASK, &raw);
                /*
                 * If power status mask has been reset, then the TCPC
                 * has reset.
                 */
                if (raw == 0xff)
                        tcpm_tcpc_reset(tcpci->port);
                else
                        tcpm_vbus_change(tcpci->port);
        }

        if (status & TCPC_ALERT_RX_STATUS) {
                struct pd_message msg;
                unsigned int cnt, payload_cnt;
                u16 header;

                regmap_read(tcpci->regmap, TCPC_RX_BYTE_CNT, &cnt);
                /*
                 * 'cnt' corresponds to READABLE_BYTE_COUNT in section 4.4.14
                 * of the TCPCI spec [Rev 2.0 Ver 1.0 October 2017] and is
                 * defined in table 4-36 as one greater than the number of
                 * bytes received. And that number includes the header. So:
                 */
                if (cnt > 3)
                        payload_cnt = cnt - (1 + sizeof(msg.header));
                else
                        payload_cnt = 0;

                tcpci_read16(tcpci, TCPC_RX_HDR, &header);
                msg.header = cpu_to_le16(header);

                if (WARN_ON(payload_cnt > sizeof(msg.payload)))
                        payload_cnt = sizeof(msg.payload);

                if (payload_cnt > 0)
                        regmap_raw_read(tcpci->regmap, TCPC_RX_DATA,
                                        &msg.payload, payload_cnt);

                /* Read complete, clear RX status alert bit */
                tcpci_write16(tcpci, TCPC_ALERT, TCPC_ALERT_RX_STATUS);

                tcpm_pd_receive(tcpci->port, &msg);
        }

        if (tcpci->data->vbus_vsafe0v && (status & TCPC_ALERT_EXTENDED_STATUS)) {
                ret = regmap_read(tcpci->regmap, TCPC_EXTENDED_STATUS, &raw);
                if (!ret && (raw & TCPC_EXTENDED_STATUS_VSAFE0V))
                        tcpm_vbus_change(tcpci->port);
        }

        if (status & TCPC_ALERT_RX_HARD_RST)
                tcpm_pd_hard_reset(tcpci->port);

        if (status & TCPC_ALERT_TX_SUCCESS)
                tcpm_pd_transmit_complete(tcpci->port, TCPC_TX_SUCCESS);
        else if (status & TCPC_ALERT_TX_DISCARDED)
                tcpm_pd_transmit_complete(tcpci->port, TCPC_TX_DISCARDED);
        else if (status & TCPC_ALERT_TX_FAILED)
                tcpm_pd_transmit_complete(tcpci->port, TCPC_TX_FAILED);

        return IRQ_HANDLED;
}
EXPORT_SYMBOL_GPL(tcpci_irq);

static irqreturn_t _tcpci_irq(int irq, void *dev_id)
{
        struct tcpci_chip *chip = dev_id;

        return tcpci_irq(chip->tcpci);
}

static const struct regmap_config tcpci_regmap_config = {
        .reg_bits = 8,
        .val_bits = 8,

        .max_register = 0x7F, /* 0x80 .. 0xFF are vendor defined */
};

static int tcpci_parse_config(struct tcpci *tcpci)
{
        tcpci->controls_vbus = true; /* XXX */

        tcpci->tcpc.fwnode = device_get_named_child_node(tcpci->dev,
                                                         "connector");
        if (!tcpci->tcpc.fwnode) {
                dev_err(tcpci->dev, "Can't find connector node.\n");
                return -EINVAL;
        }

        return 0;
}

struct tcpci *tcpci_register_port(struct device *dev, struct tcpci_data *data)
{
        struct tcpci *tcpci;
        int err;

        tcpci = devm_kzalloc(dev, sizeof(*tcpci), GFP_KERNEL);
        if (!tcpci)
                return ERR_PTR(-ENOMEM);

        tcpci->dev = dev;
        tcpci->data = data;
        tcpci->regmap = data->regmap;

        tcpci->tcpc.init = tcpci_init;
        tcpci->tcpc.get_vbus = tcpci_get_vbus;
        tcpci->tcpc.set_vbus = tcpci_set_vbus;
        tcpci->tcpc.set_cc = tcpci_set_cc;
        tcpci->tcpc.apply_rc = tcpci_apply_rc;
        tcpci->tcpc.get_cc = tcpci_get_cc;
        tcpci->tcpc.set_polarity = tcpci_set_polarity;
        tcpci->tcpc.set_vconn = tcpci_set_vconn;
        tcpci->tcpc.start_toggling = tcpci_start_toggling;

        tcpci->tcpc.set_pd_rx = tcpci_set_pd_rx;
        tcpci->tcpc.set_roles = tcpci_set_roles;
        tcpci->tcpc.pd_transmit = tcpci_pd_transmit;
        tcpci->tcpc.set_bist_data = tcpci_set_bist_data;
        tcpci->tcpc.enable_frs = tcpci_enable_frs;
        tcpci->tcpc.frs_sourcing_vbus = tcpci_frs_sourcing_vbus;
        tcpci->tcpc.set_partner_usb_comm_capable = tcpci_set_partner_usb_comm_capable;

        if (tcpci->data->auto_discharge_disconnect) {
                tcpci->tcpc.enable_auto_vbus_discharge = tcpci_enable_auto_vbus_discharge;
                tcpci->tcpc.set_auto_vbus_discharge_threshold =
                        tcpci_set_auto_vbus_discharge_threshold;
                regmap_update_bits(tcpci->regmap, TCPC_POWER_CTRL, TCPC_POWER_CTRL_BLEED_DISCHARGE,
                                   TCPC_POWER_CTRL_BLEED_DISCHARGE);
        }

        if (tcpci->data->vbus_vsafe0v)
                tcpci->tcpc.is_vbus_vsafe0v = tcpci_is_vbus_vsafe0v;

        err = tcpci_parse_config(tcpci);
        if (err < 0)
                return ERR_PTR(err);

        tcpci->port = tcpm_register_port(tcpci->dev, &tcpci->tcpc);
        if (IS_ERR(tcpci->port))
                return ERR_CAST(tcpci->port);

        return tcpci;
}
EXPORT_SYMBOL_GPL(tcpci_register_port);

void tcpci_unregister_port(struct tcpci *tcpci)
{
        tcpm_unregister_port(tcpci->port);
}
EXPORT_SYMBOL_GPL(tcpci_unregister_port);

static int tcpci_probe(struct i2c_client *client,
                       const struct i2c_device_id *i2c_id)
{
        struct tcpci_chip *chip;
        int err;
        u16 val = 0;

        chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL);
        if (!chip)
                return -ENOMEM;

        chip->data.regmap = devm_regmap_init_i2c(client, &tcpci_regmap_config);
        if (IS_ERR(chip->data.regmap))
                return PTR_ERR(chip->data.regmap);

        i2c_set_clientdata(client, chip);

        /* Disable chip interrupts before requesting irq */
        err = regmap_raw_write(chip->data.regmap, TCPC_ALERT_MASK, &val,
                               sizeof(u16));
        if (err < 0)
                return err;

        chip->tcpci = tcpci_register_port(&client->dev, &chip->data);
        if (IS_ERR(chip->tcpci))
                return PTR_ERR(chip->tcpci);

        err = devm_request_threaded_irq(&client->dev, client->irq, NULL,
                                        _tcpci_irq,
                                        IRQF_ONESHOT | IRQF_TRIGGER_LOW,
                                        dev_name(&client->dev), chip);
        if (err < 0) {
                tcpci_unregister_port(chip->tcpci);
                return err;
        }

        return 0;
}

static int tcpci_remove(struct i2c_client *client)
{
        struct tcpci_chip *chip = i2c_get_clientdata(client);
        int err;

        /* Disable chip interrupts before unregistering port */
        err = tcpci_write16(chip->tcpci, TCPC_ALERT_MASK, 0);
        if (err < 0)
                return err;

        tcpci_unregister_port(chip->tcpci);

        return 0;
}

static const struct i2c_device_id tcpci_id[] = {
        { "tcpci", 0 },
        { }
};
MODULE_DEVICE_TABLE(i2c, tcpci_id);

#ifdef CONFIG_OF
static const struct of_device_id tcpci_of_match[] = {
        { .compatible = "nxp,ptn5110", },
        {},
};
MODULE_DEVICE_TABLE(of, tcpci_of_match);
#endif

static struct i2c_driver tcpci_i2c_driver = {
        .driver = {
                .name = "tcpci",
                .of_match_table = of_match_ptr(tcpci_of_match),
        },
        .probe = tcpci_probe,
        .remove = tcpci_remove,
        .id_table = tcpci_id,
};
module_i2c_driver(tcpci_i2c_driver);

MODULE_DESCRIPTION("USB Type-C Port Controller Interface driver");
MODULE_LICENSE("GPL");