// SPDX-License-Identifier: GPL-2.0-only
/*
 * USB Power Delivery Vendor Defined Message (VDM) support code.
 *
 * Copyright 2023 Google LLC
 * Author: Prashant Malani <pmalani@chromium.org>
 */

#include <linux/module.h>
#include <linux/platform_data/cros_ec_commands.h>
#include <linux/usb/pd_vdo.h>

#include "cros_ec_typec.h"
#include "cros_typec_vdm.h"

/*
 * Retrieves pending VDM attention messages from the EC and forwards them to the altmode driver
 * based on SVID.
 */
void cros_typec_handle_vdm_attention(struct cros_typec_data *typec, int port_num)
{
        struct ec_response_typec_vdm_response resp;
        struct ec_params_typec_vdm_response req = {
                .port = port_num,
        };
        struct typec_altmode *amode;
        u16 svid;
        u32 hdr;
        int ret;

        do {
                ret = cros_ec_cmd(typec->ec, 0, EC_CMD_TYPEC_VDM_RESPONSE, &req,
                                sizeof(req), &resp, sizeof(resp));
                if (ret < 0) {
                        dev_warn(typec->dev, "Failed VDM response fetch, port: %d\n", port_num);
                        return;
                }

                hdr = resp.vdm_response[0];
                svid = PD_VDO_VID(hdr);
                dev_dbg(typec->dev, "Received VDM Attention header: %x, port: %d\n", hdr, port_num);

                amode = typec_match_altmode(typec->ports[port_num]->port_altmode,
                                            CROS_EC_ALTMODE_MAX, svid, PD_VDO_OPOS(hdr));
                if (!amode) {
                        dev_err(typec->dev,
                                "Received VDM for unregistered altmode (SVID:%x), port: %d\n",
                                svid, port_num);
                        return;
                }

                typec_altmode_attention(amode, resp.vdm_attention[1]);
        } while (resp.vdm_attention_left);
}

/*
 * Retrieves a VDM response from the EC and forwards it to the altmode driver based on SVID.
 */
void cros_typec_handle_vdm_response(struct cros_typec_data *typec, int port_num)
{
        struct ec_response_typec_vdm_response resp;
        struct ec_params_typec_vdm_response req = {
                .port = port_num,
        };
        struct typec_altmode *amode;
        u16 svid;
        u32 hdr;
        int ret;

        ret = cros_ec_cmd(typec->ec, 0, EC_CMD_TYPEC_VDM_RESPONSE, &req,
                          sizeof(req), &resp, sizeof(resp));
        if (ret < 0) {
                dev_warn(typec->dev, "Failed VDM response fetch, port: %d\n", port_num);
                return;
        }

        hdr = resp.vdm_response[0];
        svid = PD_VDO_VID(hdr);
        dev_dbg(typec->dev, "Received VDM header: %x, port: %d\n", hdr, port_num);

        amode = typec_match_altmode(typec->ports[port_num]->port_altmode, CROS_EC_ALTMODE_MAX,
                                    svid, PD_VDO_OPOS(hdr));
        if (!amode) {
                dev_err(typec->dev, "Received VDM for unregistered altmode (SVID:%x), port: %d\n",
                        svid, port_num);
                return;
        }

        ret = typec_altmode_vdm(amode, hdr, &resp.vdm_response[1], resp.vdm_data_objects);
        if (ret)
                dev_err(typec->dev, "Failed to forward VDM to altmode (SVID:%x), port: %d\n",
                        svid, port_num);
}

static int cros_typec_port_amode_enter(struct typec_altmode *amode, u32 *vdo)
{
        struct cros_typec_port *port = typec_altmode_get_drvdata(amode);
        struct ec_params_typec_control req = {
                .port = port->port_num,
                .command = TYPEC_CONTROL_COMMAND_SEND_VDM_REQ,
        };
        struct typec_vdm_req vdm_req = {};
        u32 hdr;

        hdr = VDO(amode->svid, 1, SVDM_VER_2_0, CMD_ENTER_MODE);
        hdr |= VDO_OPOS(amode->mode);

        vdm_req.vdm_data[0] = hdr;
        vdm_req.vdm_data_objects = 1;
        vdm_req.partner_type = TYPEC_PARTNER_SOP;
        req.vdm_req_params = vdm_req;

        dev_dbg(port->typec_data->dev, "Sending EnterMode VDM, hdr: %x, port: %d\n",
                hdr, port->port_num);

        return cros_ec_cmd(port->typec_data->ec, 0, EC_CMD_TYPEC_CONTROL, &req,
                           sizeof(req), NULL, 0);
}

static int cros_typec_port_amode_vdm(struct typec_altmode *amode, const u32 hdr,
                                     const u32 *vdo, int cnt)
{
        struct cros_typec_port *port = typec_altmode_get_drvdata(amode);
        struct ec_params_typec_control req = {
                .port = port->port_num,
                .command = TYPEC_CONTROL_COMMAND_SEND_VDM_REQ,
        };
        struct typec_vdm_req vdm_req = {};
        int i;

        vdm_req.vdm_data[0] = hdr;
        vdm_req.vdm_data_objects = cnt;
        for (i = 1; i < cnt; i++)
                vdm_req.vdm_data[i] = vdo[i-1];
        vdm_req.partner_type = TYPEC_PARTNER_SOP;
        req.vdm_req_params = vdm_req;

        dev_dbg(port->typec_data->dev, "Sending VDM, hdr: %x, num_objects: %d, port: %d\n",
                hdr, cnt, port->port_num);

        return cros_ec_cmd(port->typec_data->ec, 0, EC_CMD_TYPEC_CONTROL, &req,
                           sizeof(req), NULL, 0);
}

const struct typec_altmode_ops port_amode_ops = {
        .enter = cros_typec_port_amode_enter,
        .vdm = cros_typec_port_amode_vdm,
};