// SPDX-License-Identifier: GPL-2.0-only
/*
 * Remote processor messaging - sample client driver
 *
 * Copyright (C) 2011 Texas Instruments, Inc.
 * Copyright (C) 2011 Google, Inc.
 *
 * Ohad Ben-Cohen <ohad@wizery.com>
 * Brian Swetland <swetland@google.com>
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/rpmsg.h>

#define MSG             "hello world!"

static int count = 100;
module_param(count, int, 0644);

struct instance_data {
        int rx_count;
};

static int rpmsg_sample_cb(struct rpmsg_device *rpdev, void *data, int len,
                                                void *priv, u32 src)
{
        int ret;
        struct instance_data *idata = dev_get_drvdata(&rpdev->dev);

        dev_info(&rpdev->dev, "incoming msg %d (src: 0x%x)\n",
                 ++idata->rx_count, src);

        print_hex_dump_debug(__func__, DUMP_PREFIX_NONE, 16, 1, data, len,
                             true);

        /* samples should not live forever */
        if (idata->rx_count >= count) {
                dev_info(&rpdev->dev, "goodbye!\n");
                return 0;
        }

        /* send a new message now */
        ret = rpmsg_send(rpdev->ept, MSG, strlen(MSG));
        if (ret)
                dev_err(&rpdev->dev, "rpmsg_send failed: %d\n", ret);

        return 0;
}

static int rpmsg_sample_probe(struct rpmsg_device *rpdev)
{
        int ret;
        struct instance_data *idata;

        dev_info(&rpdev->dev, "new channel: 0x%x -> 0x%x!\n",
                                        rpdev->src, rpdev->dst);

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

        dev_set_drvdata(&rpdev->dev, idata);

        /* send a message to our remote processor */
        ret = rpmsg_send(rpdev->ept, MSG, strlen(MSG));
        if (ret) {
                dev_err(&rpdev->dev, "rpmsg_send failed: %d\n", ret);
                return ret;
        }

        return 0;
}

static void rpmsg_sample_remove(struct rpmsg_device *rpdev)
{
        dev_info(&rpdev->dev, "rpmsg sample client driver is removed\n");
}

static struct rpmsg_device_id rpmsg_driver_sample_id_table[] = {
        { .name = "rpmsg-client-sample" },
        { },
};
MODULE_DEVICE_TABLE(rpmsg, rpmsg_driver_sample_id_table);

static struct rpmsg_driver rpmsg_sample_client = {
        .drv.name       = KBUILD_MODNAME,
        .id_table       = rpmsg_driver_sample_id_table,
        .probe          = rpmsg_sample_probe,
        .callback       = rpmsg_sample_cb,
        .remove         = rpmsg_sample_remove,
};
module_rpmsg_driver(rpmsg_sample_client);

MODULE_DESCRIPTION("Remote processor messaging sample client driver");
MODULE_LICENSE("GPL v2");