// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright 2019 Google LLC
 */

#include <linux/errno.h>
#include <linux/export.h>
#include <linux/platform_data/wilco-ec.h>
#include <linux/string.h>
#include <linux/types.h>
#include <linux/unaligned.h>

/* Operation code; what the EC should do with the property */
enum ec_property_op {
        EC_OP_GET = 0,
        EC_OP_SET = 1,
};

struct ec_property_request {
        u8 op; /* One of enum ec_property_op */
        u8 property_id[4]; /* The 32 bit PID is stored Little Endian */
        u8 length;
        u8 data[WILCO_EC_PROPERTY_MAX_SIZE];
} __packed;

struct ec_property_response {
        u8 reserved[2];
        u8 op; /* One of enum ec_property_op */
        u8 property_id[4]; /* The 32 bit PID is stored Little Endian */
        u8 length;
        u8 data[WILCO_EC_PROPERTY_MAX_SIZE];
} __packed;

static int send_property_msg(struct wilco_ec_device *ec,
                             struct ec_property_request *rq,
                             struct ec_property_response *rs)
{
        struct wilco_ec_message ec_msg;
        int ret;

        memset(&ec_msg, 0, sizeof(ec_msg));
        ec_msg.type = WILCO_EC_MSG_PROPERTY;
        ec_msg.request_data = rq;
        ec_msg.request_size = sizeof(*rq);
        ec_msg.response_data = rs;
        ec_msg.response_size = sizeof(*rs);

        ret = wilco_ec_mailbox(ec, &ec_msg);
        if (ret < 0)
                return ret;
        if (rs->op != rq->op)
                return -EBADMSG;
        if (memcmp(rq->property_id, rs->property_id, sizeof(rs->property_id)))
                return -EBADMSG;

        return 0;
}

int wilco_ec_get_property(struct wilco_ec_device *ec,
                          struct wilco_ec_property_msg *prop_msg)
{
        struct ec_property_request rq;
        struct ec_property_response rs;
        int ret;

        memset(&rq, 0, sizeof(rq));
        rq.op = EC_OP_GET;
        put_unaligned_le32(prop_msg->property_id, rq.property_id);

        ret = send_property_msg(ec, &rq, &rs);
        if (ret < 0)
                return ret;

        prop_msg->length = rs.length;
        memcpy(prop_msg->data, rs.data, rs.length);

        return 0;
}
EXPORT_SYMBOL_GPL(wilco_ec_get_property);

int wilco_ec_set_property(struct wilco_ec_device *ec,
                          struct wilco_ec_property_msg *prop_msg)
{
        struct ec_property_request rq;
        struct ec_property_response rs;
        int ret;

        memset(&rq, 0, sizeof(rq));
        rq.op = EC_OP_SET;
        put_unaligned_le32(prop_msg->property_id, rq.property_id);
        rq.length = prop_msg->length;
        memcpy(rq.data, prop_msg->data, prop_msg->length);

        ret = send_property_msg(ec, &rq, &rs);
        if (ret < 0)
                return ret;
        if (rs.length != prop_msg->length)
                return -EBADMSG;

        return 0;
}
EXPORT_SYMBOL_GPL(wilco_ec_set_property);

int wilco_ec_get_byte_property(struct wilco_ec_device *ec, u32 property_id,
                               u8 *val)
{
        struct wilco_ec_property_msg msg;
        int ret;

        msg.property_id = property_id;

        ret = wilco_ec_get_property(ec, &msg);
        if (ret < 0)
                return ret;
        if (msg.length != 1)
                return -EBADMSG;

        *val = msg.data[0];

        return 0;
}
EXPORT_SYMBOL_GPL(wilco_ec_get_byte_property);

int wilco_ec_set_byte_property(struct wilco_ec_device *ec, u32 property_id,
                               u8 val)
{
        struct wilco_ec_property_msg msg;

        msg.property_id = property_id;
        msg.data[0] = val;
        msg.length = 1;

        return wilco_ec_set_property(ec, &msg);
}
EXPORT_SYMBOL_GPL(wilco_ec_set_byte_property);