// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (c) 2022-2024, Linaro Ltd
 * Authors:
 *  Bjorn Andersson
 *  Dmitry Baryshkov
 */
#include <linux/auxiliary_bus.h>
#include <linux/bitops.h>
#include <linux/bitfield.h>
#include <linux/completion.h>
#include <linux/container_of.h>
#include <linux/module.h>
#include <linux/notifier.h>
#include <linux/of.h>
#include <linux/property.h>
#include <linux/string.h>
#include <linux/platform_data/lenovo-yoga-c630.h>
#include <linux/usb/typec_dp.h>

#include <drm/bridge/aux-bridge.h>

#include "ucsi.h"

#define LENOVO_EC_USB_MUX       0x08

#define USB_MUX_MUXC    GENMASK(1, 0)
#define USB_MUX_CCST    GENMASK(3, 2)
#define USB_MUX_DPPN    GENMASK(7, 4)
#define USB_MUX_HPDS    BIT(8)
#define USB_MUX_HSFL    GENMASK(11, 9)

struct yoga_c630_ucsi {
        struct yoga_c630_ec *ec;
        struct ucsi *ucsi;
        struct auxiliary_device *bridge;
        struct notifier_block nb;
        u16 version;
};

static int yoga_c630_ucsi_read_version(struct ucsi *ucsi, u16 *version)
{
        struct yoga_c630_ucsi *uec = ucsi_get_drvdata(ucsi);

        *version = uec->version;

        return 0;
}

static int yoga_c630_ucsi_read_cci(struct ucsi *ucsi, u32 *cci)
{
        struct yoga_c630_ucsi *uec = ucsi_get_drvdata(ucsi);
        u8 buf[YOGA_C630_UCSI_READ_SIZE];
        int ret;

        ret = yoga_c630_ec_ucsi_read(uec->ec, buf);
        if (ret)
                return ret;

        memcpy(cci, buf, sizeof(*cci));

        return 0;
}

static int yoga_c630_ucsi_read_message_in(struct ucsi *ucsi,
                                          void *val, size_t val_len)
{
        struct yoga_c630_ucsi *uec = ucsi_get_drvdata(ucsi);
        u8 buf[YOGA_C630_UCSI_READ_SIZE];
        int ret;

        ret = yoga_c630_ec_ucsi_read(uec->ec, buf);
        if (ret)
                return ret;

        memcpy(val, buf + YOGA_C630_UCSI_CCI_SIZE,
               min(val_len, YOGA_C630_UCSI_DATA_SIZE));

        return 0;
}

static int yoga_c630_ucsi_async_control(struct ucsi *ucsi, u64 command)
{
        struct yoga_c630_ucsi *uec = ucsi_get_drvdata(ucsi);

        return yoga_c630_ec_ucsi_write(uec->ec, (u8*)&command);
}

static int yoga_c630_ucsi_sync_control(struct ucsi *ucsi,
                                       u64 command,
                                       u32 *cci,
                                       void *data, size_t size)
{
        int ret;

        /*
         * EC doesn't return connector's DP mode even though it is supported.
         * Fake it.
         */
        if (UCSI_COMMAND(command) == UCSI_GET_ALTERNATE_MODES &&
            UCSI_GET_ALTMODE_GET_CONNECTOR_NUMBER(command) == 1 &&
            UCSI_ALTMODE_RECIPIENT(command) == UCSI_RECIPIENT_CON &&
            UCSI_ALTMODE_OFFSET(command) == 0) {
                static const struct ucsi_altmode alt = {
                        .svid = USB_TYPEC_DP_SID,
                        .mid = USB_TYPEC_DP_MODE,
                };

                dev_dbg(ucsi->dev, "faking DP altmode for con1\n");
                memset(data, 0, size);
                memcpy(data, &alt, min(sizeof(alt), size));
                *cci = UCSI_CCI_COMMAND_COMPLETE | UCSI_SET_CCI_LENGTH(sizeof(alt));
                return 0;
        }

        /*
         * EC can return AltModes present on CON1 (port0, right) for CON2
         * (port1, left) too. Ignore all requests going to CON2 (it doesn't
         * support DP anyway).
         */
        if (UCSI_COMMAND(command) == UCSI_GET_ALTERNATE_MODES &&
            UCSI_GET_ALTMODE_GET_CONNECTOR_NUMBER(command) == 2) {
                dev_dbg(ucsi->dev, "ignoring altmodes for con2\n");
                memset(data, 0, size);
                *cci = UCSI_CCI_COMMAND_COMPLETE;
                return 0;
        }

        ret = ucsi_sync_control_common(ucsi, command, cci, data, size);
        if (ret < 0)
                return ret;

        /* UCSI_GET_CURRENT_CAM is off-by-one on all ports */
        if (UCSI_COMMAND(command) == UCSI_GET_CURRENT_CAM && data)
                ((u8 *)data)[0]--;

        return ret;
}

static bool yoga_c630_ucsi_update_altmodes(struct ucsi *ucsi,
                                           u8 recipient,
                                           struct ucsi_altmode *orig,
                                           struct ucsi_altmode *updated)
{
        int i;

        if (orig[0].svid == 0 || recipient != UCSI_RECIPIENT_SOP)
                return false;

        /* EC is nice and repeats altmodes again and again. Ignore copies. */
        for (i = 1; i < UCSI_MAX_ALTMODES; i++) {
                if (orig[i].svid == orig[0].svid) {
                        dev_dbg(ucsi->dev, "Found duplicate altmodes, starting from %d\n", i);
                        memset(&orig[i], 0, (UCSI_MAX_ALTMODES - i) * sizeof(*orig));
                        break;
                }
        }

        return false;
}

static void yoga_c630_ucsi_update_connector(struct ucsi_connector *con)
{
        if (con->num == 1)
                con->typec_cap.orientation_aware = true;
}

static const struct ucsi_operations yoga_c630_ucsi_ops = {
        .read_version = yoga_c630_ucsi_read_version,
        .read_cci = yoga_c630_ucsi_read_cci,
        .poll_cci = yoga_c630_ucsi_read_cci,
        .read_message_in = yoga_c630_ucsi_read_message_in,
        .sync_control = yoga_c630_ucsi_sync_control,
        .async_control = yoga_c630_ucsi_async_control,
        .update_altmodes = yoga_c630_ucsi_update_altmodes,
        .update_connector = yoga_c630_ucsi_update_connector,
};

static void yoga_c630_ucsi_read_port0_status(struct yoga_c630_ucsi *uec)
{
        int val;
        unsigned int muxc, ccst, dppn, hpds, hsfl;

        val = yoga_c630_ec_read16(uec->ec, LENOVO_EC_USB_MUX);

        muxc = FIELD_GET(USB_MUX_MUXC, val);
        ccst = FIELD_GET(USB_MUX_CCST, val);
        dppn = FIELD_GET(USB_MUX_DPPN, val);
        hpds = FIELD_GET(USB_MUX_HPDS, val);
        hsfl = FIELD_GET(USB_MUX_HSFL, val);

        dev_dbg(uec->ucsi->dev, " mux %04x (muxc %d ccst %d dppn %d hpds %d hsfl %d)\n",
                val,
                muxc, ccst, dppn, hpds, hsfl);

        if (uec->ucsi->connector && uec->ucsi->connector[0].port)
                typec_set_orientation(uec->ucsi->connector[0].port,
                                      ccst == 1 ?
                                      TYPEC_ORIENTATION_REVERSE :
                                      TYPEC_ORIENTATION_NORMAL);

        if (uec->bridge)
                drm_aux_hpd_bridge_notify(&uec->bridge->dev,
                                          dppn != 0 ?
                                          connector_status_connected :
                                          connector_status_disconnected);

}

static int yoga_c630_ucsi_notify(struct notifier_block *nb,
                                 unsigned long action, void *data)
{
        struct yoga_c630_ucsi *uec = container_of(nb, struct yoga_c630_ucsi, nb);
        u32 cci;
        int ret;

        switch (action) {
        case LENOVO_EC_EVENT_USB:
        case LENOVO_EC_EVENT_HPD:
                yoga_c630_ucsi_read_port0_status(uec);
                ucsi_connector_change(uec->ucsi, 1);
                return NOTIFY_OK;

        case LENOVO_EC_EVENT_UCSI:
                ret = uec->ucsi->ops->read_cci(uec->ucsi, &cci);
                if (ret)
                        return NOTIFY_DONE;

                ucsi_notify_common(uec->ucsi, cci);

                return NOTIFY_OK;

        default:
                return NOTIFY_DONE;
        }
}

static int yoga_c630_ucsi_probe(struct auxiliary_device *adev,
                                const struct auxiliary_device_id *id)
{
        struct yoga_c630_ec *ec = adev->dev.platform_data;
        struct yoga_c630_ucsi *uec;
        int ret;

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

        uec->ec = ec;
        uec->nb.notifier_call = yoga_c630_ucsi_notify;

        device_for_each_child_node_scoped(&adev->dev, fwnode) {
                u32 port;

                ret = fwnode_property_read_u32(fwnode, "reg", &port);
                if (ret < 0) {
                        dev_err(&adev->dev, "missing reg property of %pfwP\n", fwnode);
                        return ret;
                }

                /* DP is only on port0 */
                if (port != 0)
                        continue;

                uec->bridge = devm_drm_dp_hpd_bridge_alloc(&adev->dev, to_of_node(fwnode));
                if (IS_ERR(uec->bridge))
                        return PTR_ERR(uec->bridge);
        }

        uec->ucsi = ucsi_create(&adev->dev, &yoga_c630_ucsi_ops);
        if (IS_ERR(uec->ucsi))
                return PTR_ERR(uec->ucsi);

        ucsi_set_drvdata(uec->ucsi, uec);

        uec->version = yoga_c630_ec_ucsi_get_version(uec->ec);

        auxiliary_set_drvdata(adev, uec);

        ret = yoga_c630_ec_register_notify(ec, &uec->nb);
        if (ret)
                goto err_destroy;

        ret = ucsi_register(uec->ucsi);
        if (ret)
                goto err_unregister;

        if (uec->bridge) {
                ret = devm_drm_dp_hpd_bridge_add(&adev->dev, uec->bridge);
                if (ret)
                        goto err_ucsi_unregister;
        }

        return 0;

err_ucsi_unregister:
        ucsi_unregister(uec->ucsi);

err_unregister:
        yoga_c630_ec_unregister_notify(uec->ec, &uec->nb);

err_destroy:
        ucsi_destroy(uec->ucsi);

        return ret;
}

static void yoga_c630_ucsi_remove(struct auxiliary_device *adev)
{
        struct yoga_c630_ucsi *uec = auxiliary_get_drvdata(adev);

        ucsi_unregister(uec->ucsi);
        yoga_c630_ec_unregister_notify(uec->ec, &uec->nb);
        ucsi_destroy(uec->ucsi);
}

static const struct auxiliary_device_id yoga_c630_ucsi_id_table[] = {
        { .name = YOGA_C630_MOD_NAME "." YOGA_C630_DEV_UCSI, },
        {}
};
MODULE_DEVICE_TABLE(auxiliary, yoga_c630_ucsi_id_table);

static struct auxiliary_driver yoga_c630_ucsi_driver = {
        .name = YOGA_C630_DEV_UCSI,
        .id_table = yoga_c630_ucsi_id_table,
        .probe = yoga_c630_ucsi_probe,
        .remove = yoga_c630_ucsi_remove,
};

module_auxiliary_driver(yoga_c630_ucsi_driver);

MODULE_DESCRIPTION("Lenovo Yoga C630 UCSI");
MODULE_LICENSE("GPL");