// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * PowerNV sensor code
 *
 * Copyright (C) 2013 IBM
 */

#include <linux/delay.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <asm/opal.h>
#include <asm/machdep.h>

/*
 * This will return sensor information to driver based on the requested sensor
 * handle. A handle is an opaque id for the powernv, read by the driver from the
 * device tree..
 */
int opal_get_sensor_data(u32 sensor_hndl, u32 *sensor_data)
{
        int ret, token;
        struct opal_msg msg;
        __be32 data;

        token = opal_async_get_token_interruptible();
        if (token < 0)
                return token;

        ret = opal_sensor_read(sensor_hndl, token, &data);
        switch (ret) {
        case OPAL_ASYNC_COMPLETION:
                ret = opal_async_wait_response(token, &msg);
                if (ret) {
                        pr_err("%s: Failed to wait for the async response, %d\n",
                               __func__, ret);
                        goto out;
                }

                ret = opal_error_code(opal_get_async_rc(msg));
                *sensor_data = be32_to_cpu(data);
                break;

        case OPAL_SUCCESS:
                ret = 0;
                *sensor_data = be32_to_cpu(data);
                break;

        case OPAL_WRONG_STATE:
                ret = -EIO;
                break;

        default:
                ret = opal_error_code(ret);
                break;
        }

out:
        opal_async_release_token(token);
        return ret;
}
EXPORT_SYMBOL_GPL(opal_get_sensor_data);

int opal_get_sensor_data_u64(u32 sensor_hndl, u64 *sensor_data)
{
        int ret, token;
        struct opal_msg msg;
        __be64 data;

        if (!opal_check_token(OPAL_SENSOR_READ_U64)) {
                u32 sdata;

                ret = opal_get_sensor_data(sensor_hndl, &sdata);
                if (!ret)
                        *sensor_data = sdata;
                return ret;
        }

        token = opal_async_get_token_interruptible();
        if (token < 0)
                return token;

        ret = opal_sensor_read_u64(sensor_hndl, token, &data);
        switch (ret) {
        case OPAL_ASYNC_COMPLETION:
                ret = opal_async_wait_response(token, &msg);
                if (ret) {
                        pr_err("%s: Failed to wait for the async response, %d\n",
                               __func__, ret);
                        goto out_token;
                }

                ret = opal_error_code(opal_get_async_rc(msg));
                *sensor_data = be64_to_cpu(data);
                break;

        case OPAL_SUCCESS:
                ret = 0;
                *sensor_data = be64_to_cpu(data);
                break;

        case OPAL_WRONG_STATE:
                ret = -EIO;
                break;

        default:
                ret = opal_error_code(ret);
                break;
        }

out_token:
        opal_async_release_token(token);
        return ret;
}
EXPORT_SYMBOL_GPL(opal_get_sensor_data_u64);

int __init opal_sensor_init(void)
{
        struct platform_device *pdev;
        struct device_node *sensor;

        sensor = of_find_node_by_path("/ibm,opal/sensors");
        if (!sensor) {
                pr_err("Opal node 'sensors' not found\n");
                return -ENODEV;
        }

        pdev = of_platform_device_create(sensor, "opal-sensor", NULL);
        of_node_put(sensor);

        return PTR_ERR_OR_ZERO(pdev);
}