// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright 2023 IBM Corp.
 */

#include <linux/debugfs.h>
#include <linux/device.h>
#include <linux/fs.h>
#include <linux/i2c.h>
#include <linux/minmax.h>
#include <linux/module.h>
#include <linux/pmbus.h>
#include <linux/hwmon-sysfs.h>
#include "pmbus.h"

#define ACBEL_MFR_FW_REVISION   0xd9

static ssize_t acbel_fsg032_debugfs_read(struct file *file, char __user *buf, size_t count,
                                         loff_t *ppos)
{
        struct i2c_client *client = file->private_data;
        u8 data[I2C_SMBUS_BLOCK_MAX + 2] = { 0 };
        char out[8];
        int rc;

        rc = i2c_smbus_read_block_data(client, ACBEL_MFR_FW_REVISION, data);
        if (rc < 0)
                return rc;

        rc = snprintf(out, sizeof(out), "%*phN\n", min(rc, 3), data);
        return simple_read_from_buffer(buf, count, ppos, out, rc);
}

static const struct file_operations acbel_debugfs_ops = {
        .llseek = noop_llseek,
        .read = acbel_fsg032_debugfs_read,
        .write = NULL,
        .open = simple_open,
};

static void acbel_fsg032_init_debugfs(struct i2c_client *client)
{
        struct dentry *debugfs = pmbus_get_debugfs_dir(client);

        if (!debugfs)
                return;

        debugfs_create_file("fw_version", 0444, debugfs, client, &acbel_debugfs_ops);
}

static const struct i2c_device_id acbel_fsg032_id[] = {
        { "acbel_fsg032" },
        {}
};

static struct pmbus_driver_info acbel_fsg032_info = {
        .pages = 1,
        .func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_IIN | PMBUS_HAVE_PIN |
                   PMBUS_HAVE_VOUT | PMBUS_HAVE_IOUT | PMBUS_HAVE_POUT |
                   PMBUS_HAVE_TEMP | PMBUS_HAVE_TEMP2 | PMBUS_HAVE_TEMP3 |
                   PMBUS_HAVE_FAN12 | PMBUS_HAVE_STATUS_VOUT |
                   PMBUS_HAVE_STATUS_IOUT | PMBUS_HAVE_STATUS_TEMP |
                   PMBUS_HAVE_STATUS_INPUT | PMBUS_HAVE_STATUS_FAN12,
};

static int acbel_fsg032_probe(struct i2c_client *client)
{
        u8 buf[I2C_SMBUS_BLOCK_MAX + 1];
        struct device *dev = &client->dev;
        int rc;

        rc = i2c_smbus_read_block_data(client, PMBUS_MFR_ID, buf);
        if (rc < 0) {
                dev_err(dev, "Failed to read PMBUS_MFR_ID\n");
                return rc;
        }
        if (strncmp(buf, "ACBEL", 5)) {
                buf[rc] = '\0';
                dev_err(dev, "Manufacturer '%s' not supported\n", buf);
                return -ENODEV;
        }

        rc = i2c_smbus_read_block_data(client, PMBUS_MFR_MODEL, buf);
        if (rc < 0) {
                dev_err(dev, "Failed to read PMBUS_MFR_MODEL\n");
                return rc;
        }

        if (strncmp(buf, "FSG032", 6)) {
                buf[rc] = '\0';
                dev_err(dev, "Model '%s' not supported\n", buf);
                return -ENODEV;
        }

        rc = pmbus_do_probe(client, &acbel_fsg032_info);
        if (rc)
                return rc;

        acbel_fsg032_init_debugfs(client);
        return 0;
}

static const struct of_device_id acbel_fsg032_of_match[] = {
        { .compatible = "acbel,fsg032" },
        {}
};
MODULE_DEVICE_TABLE(of, acbel_fsg032_of_match);

static struct i2c_driver acbel_fsg032_driver = {
        .driver = {
                .name = "acbel-fsg032",
                .of_match_table = acbel_fsg032_of_match,
        },
        .probe = acbel_fsg032_probe,
        .id_table = acbel_fsg032_id,
};

module_i2c_driver(acbel_fsg032_driver);

MODULE_AUTHOR("Lakshmi Yadlapati");
MODULE_DESCRIPTION("PMBus driver for AcBel Power System power supplies");
MODULE_LICENSE("GPL");
MODULE_IMPORT_NS("PMBUS");