// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * i5500_temp - Driver for Intel 5500/5520/X58 chipset thermal sensor
 *
 * Copyright (C) 2012, 2014 Jean Delvare <jdelvare@suse.de>
 */

#include <linux/bitops.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/device.h>
#include <linux/pci.h>
#include <linux/hwmon.h>
#include <linux/err.h>

/* Register definitions from datasheet */
#define REG_TSTHRCATA   0xE2
#define REG_TSCTRL      0xE8
#define REG_TSTHRRPEX   0xEB
#define REG_TSTHRLO     0xEC
#define REG_TSTHRHI     0xEE
#define REG_CTHINT      0xF0
#define REG_TSFSC       0xF3
#define REG_CTSTS       0xF4
#define REG_TSTHRRQPI   0xF5
#define REG_CTCTRL      0xF7
#define REG_TSTIMER     0xF8

static int i5500_read(struct device *dev, enum hwmon_sensor_types type, u32 attr, int channel,
                      long *val)
{
        struct pci_dev *pdev = to_pci_dev(dev->parent);
        u16 tsthr;
        s8 tsfsc;
        u8 ctsts;

        switch (type) {
        case hwmon_temp:
                switch (attr) {
                /* Sensor resolution : 0.5 degree C */
                case hwmon_temp_input:
                        pci_read_config_word(pdev, REG_TSTHRHI, &tsthr);
                        pci_read_config_byte(pdev, REG_TSFSC, &tsfsc);
                        *val = (tsthr - tsfsc) * 500;
                        return 0;
                case hwmon_temp_max:
                        pci_read_config_word(pdev, REG_TSTHRHI, &tsthr);
                        *val = tsthr * 500;
                        return 0;
                case hwmon_temp_max_hyst:
                        pci_read_config_word(pdev, REG_TSTHRLO, &tsthr);
                        *val = tsthr * 500;
                        return 0;
                case hwmon_temp_crit:
                        pci_read_config_word(pdev, REG_TSTHRCATA, &tsthr);
                        *val = tsthr * 500;
                        return 0;
                case hwmon_temp_max_alarm:
                        pci_read_config_byte(pdev, REG_CTSTS, &ctsts);
                        *val = !!(ctsts & BIT(1));
                        return 0;
                case hwmon_temp_crit_alarm:
                        pci_read_config_byte(pdev, REG_CTSTS, &ctsts);
                        *val = !!(ctsts & BIT(0));
                        return 0;
                default:
                        break;
                }
                break;
        default:
                break;
        }

        return -EOPNOTSUPP;
}

static const struct hwmon_ops i5500_ops = {
        .visible = 0444,
        .read = i5500_read,
};

static const struct hwmon_channel_info * const i5500_info[] = {
        HWMON_CHANNEL_INFO(chip, HWMON_C_REGISTER_TZ),
        HWMON_CHANNEL_INFO(temp,
                           HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MAX_HYST | HWMON_T_CRIT |
                           HWMON_T_MAX_ALARM | HWMON_T_CRIT_ALARM
                           ),
        NULL
};

static const struct hwmon_chip_info i5500_chip_info = {
        .ops = &i5500_ops,
        .info = i5500_info,
};

static const struct pci_device_id i5500_temp_ids[] = {
        { PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x3438) },
        { 0 },
};

MODULE_DEVICE_TABLE(pci, i5500_temp_ids);

static int i5500_temp_probe(struct pci_dev *pdev,
                            const struct pci_device_id *id)
{
        int err;
        struct device *hwmon_dev;
        u32 tstimer;
        s8 tsfsc;

        err = pcim_enable_device(pdev);
        if (err) {
                dev_err(&pdev->dev, "Failed to enable device\n");
                return err;
        }

        pci_read_config_byte(pdev, REG_TSFSC, &tsfsc);
        pci_read_config_dword(pdev, REG_TSTIMER, &tstimer);
        if (tsfsc == 0x7F && tstimer == 0x07D30D40) {
                dev_notice(&pdev->dev, "Sensor seems to be disabled\n");
                return -ENODEV;
        }

        hwmon_dev = devm_hwmon_device_register_with_info(&pdev->dev, "intel5500", NULL,
                                                         &i5500_chip_info, NULL);
        return PTR_ERR_OR_ZERO(hwmon_dev);
}

static struct pci_driver i5500_temp_driver = {
        .name = "i5500_temp",
        .id_table = i5500_temp_ids,
        .probe = i5500_temp_probe,
};

module_pci_driver(i5500_temp_driver);

MODULE_AUTHOR("Jean Delvare <jdelvare@suse.de>");
MODULE_DESCRIPTION("Intel 5500/5520/X58 chipset thermal sensor driver");
MODULE_LICENSE("GPL");