// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (c) 2019-2022, The Linux Foundation. All rights reserved.
 * Copyright (c) 2023, Linaro Ltd
 */
#include <linux/of_device.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/rpmsg.h>
#include <linux/slab.h>
#include <linux/soc/qcom/pdr.h>
#include <linux/debugfs.h>

#define CREATE_TRACE_POINTS
#include "pmic_pdcharger_ulog.h"

#define MSG_OWNER_CHG_ULOG              32778
#define MSG_TYPE_REQ_RESP               1

#define GET_CHG_ULOG_REQ                0x18
#define SET_CHG_ULOG_PROP_REQ           0x19

#define LOG_DEFAULT_TIME_MS             1000

#define MAX_ULOG_SIZE                   8192

struct pmic_pdcharger_ulog_hdr {
        __le32 owner;
        __le32 type;
        __le32 opcode;
};

struct pmic_pdcharger_ulog {
        struct rpmsg_device *rpdev;
        struct delayed_work ulog_work;
};

struct get_ulog_req_msg {
        struct pmic_pdcharger_ulog_hdr  hdr;
        u32                             log_size;
};

struct get_ulog_resp_msg {
        struct pmic_pdcharger_ulog_hdr  hdr;
        u8                              buf[MAX_ULOG_SIZE];
};

static int pmic_pdcharger_ulog_write_async(struct pmic_pdcharger_ulog *pg, void *data, size_t len)
{
        return rpmsg_send(pg->rpdev->ept, data, len);
}

static int pmic_pdcharger_ulog_request(struct pmic_pdcharger_ulog *pg)
{
        struct get_ulog_req_msg req_msg = {
                .hdr = {
                        .owner = cpu_to_le32(MSG_OWNER_CHG_ULOG),
                        .type = cpu_to_le32(MSG_TYPE_REQ_RESP),
                        .opcode = cpu_to_le32(GET_CHG_ULOG_REQ)
                },
                .log_size = MAX_ULOG_SIZE
        };

        return pmic_pdcharger_ulog_write_async(pg, &req_msg, sizeof(req_msg));
}

static void pmic_pdcharger_ulog_work(struct work_struct *work)
{
        struct pmic_pdcharger_ulog *pg = container_of(work, struct pmic_pdcharger_ulog,
                                                      ulog_work.work);
        int rc;

        rc = pmic_pdcharger_ulog_request(pg);
        if (rc) {
                dev_err(&pg->rpdev->dev, "Error requesting ulog, rc=%d\n", rc);
                return;
        }
}

static void pmic_pdcharger_ulog_handle_message(struct pmic_pdcharger_ulog *pg,
                                               struct get_ulog_resp_msg *resp_msg,
                                               size_t len)
{
        char *token, *buf = resp_msg->buf;

        if (len != sizeof(*resp_msg)) {
                dev_err(&pg->rpdev->dev, "Expected data length: %zu, received: %zu\n",
                        sizeof(*resp_msg), len);
                return;
        }

        buf[MAX_ULOG_SIZE - 1] = '\0';

        do {
                token = strsep((char **)&buf, "\n");
                if (token && strlen(token))
                        trace_pmic_pdcharger_ulog_msg(token);
        } while (token);
}

static int pmic_pdcharger_ulog_rpmsg_callback(struct rpmsg_device *rpdev, void *data,
                                              int len, void *priv, u32 addr)
{
        struct pmic_pdcharger_ulog *pg = dev_get_drvdata(&rpdev->dev);
        struct pmic_pdcharger_ulog_hdr *hdr = data;
        u32 opcode;

        opcode = le32_to_cpu(hdr->opcode);

        switch (opcode) {
        case GET_CHG_ULOG_REQ:
                schedule_delayed_work(&pg->ulog_work, msecs_to_jiffies(LOG_DEFAULT_TIME_MS));
                pmic_pdcharger_ulog_handle_message(pg, data, len);
                break;
        default:
                dev_err(&pg->rpdev->dev, "Unknown opcode %u\n", opcode);
                break;
        }

        return 0;
}

static int pmic_pdcharger_ulog_rpmsg_probe(struct rpmsg_device *rpdev)
{
        struct pmic_pdcharger_ulog *pg;
        struct device *dev = &rpdev->dev;

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

        pg->rpdev = rpdev;
        INIT_DELAYED_WORK(&pg->ulog_work, pmic_pdcharger_ulog_work);

        dev_set_drvdata(dev, pg);

        pmic_pdcharger_ulog_request(pg);

        return 0;
}

static void pmic_pdcharger_ulog_rpmsg_remove(struct rpmsg_device *rpdev)
{
        struct pmic_pdcharger_ulog *pg = dev_get_drvdata(&rpdev->dev);

        cancel_delayed_work_sync(&pg->ulog_work);
}

static const struct rpmsg_device_id pmic_pdcharger_ulog_rpmsg_id_match[] = {
        { "PMIC_LOGS_ADSP_APPS" },
        {}
};
/*
 * No MODULE_DEVICE_TABLE intentionally: that's a debugging module, to be
 * loaded manually only.
 */

static struct rpmsg_driver pmic_pdcharger_ulog_rpmsg_driver = {
        .probe = pmic_pdcharger_ulog_rpmsg_probe,
        .remove = pmic_pdcharger_ulog_rpmsg_remove,
        .callback = pmic_pdcharger_ulog_rpmsg_callback,
        .id_table = pmic_pdcharger_ulog_rpmsg_id_match,
        .drv  = {
                .name  = "qcom_pmic_pdcharger_ulog_rpmsg",
        },
};

module_rpmsg_driver(pmic_pdcharger_ulog_rpmsg_driver);
MODULE_DESCRIPTION("Qualcomm PMIC ChargerPD ULOG driver");
MODULE_LICENSE("GPL");