// SPDX-License-Identifier: GPL-2.0
/*
 * adm1029.c - Part of lm_sensors, Linux kernel modules for hardware monitoring
 *
 * Copyright (C) 2006 Corentin LABBE <clabbe.montjoie@gmail.com>
 *
 * Based on LM83 Driver by Jean Delvare <jdelvare@suse.de>
 *
 * Give only processor, motherboard temperatures and fan tachs
 * Very rare chip please let me know if you use it
 *
 * http://www.analog.com/UploadedFiles/Data_Sheets/ADM1029.pdf
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/jiffies.h>
#include <linux/i2c.h>
#include <linux/hwmon-sysfs.h>
#include <linux/hwmon.h>
#include <linux/err.h>
#include <linux/mutex.h>

/*
 * Addresses to scan
 */

static const unsigned short normal_i2c[] = { 0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d,
                                                0x2e, 0x2f, I2C_CLIENT_END
};

/*
 * The ADM1029 registers
 * Manufacturer ID is 0x41 for Analog Devices
 */

#define ADM1029_REG_MAN_ID                      0x0D
#define ADM1029_REG_CHIP_ID                     0x0E
#define ADM1029_REG_CONFIG                      0x01
#define ADM1029_REG_NB_FAN_SUPPORT              0x02

#define ADM1029_REG_TEMP_DEVICES_INSTALLED      0x06

#define ADM1029_REG_LOCAL_TEMP                  0xA0
#define ADM1029_REG_REMOTE1_TEMP                0xA1
#define ADM1029_REG_REMOTE2_TEMP                0xA2

#define ADM1029_REG_LOCAL_TEMP_HIGH             0x90
#define ADM1029_REG_REMOTE1_TEMP_HIGH           0x91
#define ADM1029_REG_REMOTE2_TEMP_HIGH           0x92

#define ADM1029_REG_LOCAL_TEMP_LOW              0x98
#define ADM1029_REG_REMOTE1_TEMP_LOW            0x99
#define ADM1029_REG_REMOTE2_TEMP_LOW            0x9A

#define ADM1029_REG_FAN1                        0x70
#define ADM1029_REG_FAN2                        0x71

#define ADM1029_REG_FAN1_MIN                    0x78
#define ADM1029_REG_FAN2_MIN                    0x79

#define ADM1029_REG_FAN1_CONFIG                 0x68
#define ADM1029_REG_FAN2_CONFIG                 0x69

#define TEMP_FROM_REG(val)      ((val) * 1000)

#define DIV_FROM_REG(val)       (1 << (((val) >> 6) - 1))

/* Registers to be checked by adm1029_update_device() */
static const u8 ADM1029_REG_TEMP[] = {
        ADM1029_REG_LOCAL_TEMP,
        ADM1029_REG_REMOTE1_TEMP,
        ADM1029_REG_REMOTE2_TEMP,
        ADM1029_REG_LOCAL_TEMP_HIGH,
        ADM1029_REG_REMOTE1_TEMP_HIGH,
        ADM1029_REG_REMOTE2_TEMP_HIGH,
        ADM1029_REG_LOCAL_TEMP_LOW,
        ADM1029_REG_REMOTE1_TEMP_LOW,
        ADM1029_REG_REMOTE2_TEMP_LOW,
};

static const u8 ADM1029_REG_FAN[] = {
        ADM1029_REG_FAN1,
        ADM1029_REG_FAN2,
        ADM1029_REG_FAN1_MIN,
        ADM1029_REG_FAN2_MIN,
};

static const u8 ADM1029_REG_FAN_DIV[] = {
        ADM1029_REG_FAN1_CONFIG,
        ADM1029_REG_FAN2_CONFIG,
};

/*
 * Client data (each client gets its own)
 */

struct adm1029_data {
        struct i2c_client *client;
        struct mutex update_lock; /* protect register access */
        bool valid;             /* false until following fields are valid */
        unsigned long last_updated;     /* in jiffies */

        /* registers values, signed for temperature, unsigned for other stuff */
        s8 temp[ARRAY_SIZE(ADM1029_REG_TEMP)];
        u8 fan[ARRAY_SIZE(ADM1029_REG_FAN)];
        u8 fan_div[ARRAY_SIZE(ADM1029_REG_FAN_DIV)];
};

/*
 * function that update the status of the chips (temperature for example)
 */
static struct adm1029_data *adm1029_update_device(struct device *dev)
{
        struct adm1029_data *data = dev_get_drvdata(dev);
        struct i2c_client *client = data->client;

        mutex_lock(&data->update_lock);
        /*
         * Use the "cache" Luke, don't recheck values
         * if there are already checked not a long time later
         */
        if (time_after(jiffies, data->last_updated + HZ * 2) || !data->valid) {
                int nr;

                dev_dbg(&client->dev, "Updating adm1029 data\n");

                for (nr = 0; nr < ARRAY_SIZE(ADM1029_REG_TEMP); nr++) {
                        data->temp[nr] =
                            i2c_smbus_read_byte_data(client,
                                                     ADM1029_REG_TEMP[nr]);
                }
                for (nr = 0; nr < ARRAY_SIZE(ADM1029_REG_FAN); nr++) {
                        data->fan[nr] =
                            i2c_smbus_read_byte_data(client,
                                                     ADM1029_REG_FAN[nr]);
                }
                for (nr = 0; nr < ARRAY_SIZE(ADM1029_REG_FAN_DIV); nr++) {
                        data->fan_div[nr] =
                            i2c_smbus_read_byte_data(client,
                                                     ADM1029_REG_FAN_DIV[nr]);
                }

                data->last_updated = jiffies;
                data->valid = true;
        }

        mutex_unlock(&data->update_lock);

        return data;
}

/*
 * Sysfs stuff
 */

static ssize_t
temp_show(struct device *dev, struct device_attribute *devattr, char *buf)
{
        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
        struct adm1029_data *data = adm1029_update_device(dev);

        return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp[attr->index]));
}

static ssize_t
fan_show(struct device *dev, struct device_attribute *devattr, char *buf)
{
        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
        struct adm1029_data *data = adm1029_update_device(dev);
        u16 val;

        mutex_lock(&data->update_lock);
        if (data->fan[attr->index] == 0 ||
            (data->fan_div[attr->index] & 0xC0) == 0 ||
            data->fan[attr->index] == 255) {
                mutex_unlock(&data->update_lock);
                return sprintf(buf, "0\n");
        }

        val = 1880 * 120 / DIV_FROM_REG(data->fan_div[attr->index])
            / data->fan[attr->index];
        mutex_unlock(&data->update_lock);
        return sprintf(buf, "%d\n", val);
}

static ssize_t
fan_div_show(struct device *dev, struct device_attribute *devattr, char *buf)
{
        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
        struct adm1029_data *data = adm1029_update_device(dev);

        if ((data->fan_div[attr->index] & 0xC0) == 0)
                return sprintf(buf, "0\n");
        return sprintf(buf, "%d\n", DIV_FROM_REG(data->fan_div[attr->index]));
}

static ssize_t fan_div_store(struct device *dev,
                             struct device_attribute *devattr,
                             const char *buf, size_t count)
{
        struct adm1029_data *data = dev_get_drvdata(dev);
        struct i2c_client *client = data->client;
        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
        u8 reg;
        long val;
        int ret = kstrtol(buf, 10, &val);

        if (ret < 0)
                return ret;

        mutex_lock(&data->update_lock);

        /*Read actual config */
        reg = i2c_smbus_read_byte_data(client,
                                       ADM1029_REG_FAN_DIV[attr->index]);

        switch (val) {
        case 1:
                val = 1;
                break;
        case 2:
                val = 2;
                break;
        case 4:
                val = 3;
                break;
        default:
                mutex_unlock(&data->update_lock);
                dev_err(&client->dev,
                        "fan_div value %ld not supported. Choose one of 1, 2 or 4!\n",
                        val);
                return -EINVAL;
        }
        /* Update the value */
        reg = (reg & 0x3F) | (val << 6);

        /* Update the cache */
        data->fan_div[attr->index] = reg;

        /* Write value */
        i2c_smbus_write_byte_data(client,
                                  ADM1029_REG_FAN_DIV[attr->index], reg);
        mutex_unlock(&data->update_lock);

        return count;
}

/* Access rights on sysfs. */
static SENSOR_DEVICE_ATTR_RO(temp1_input, temp, 0);
static SENSOR_DEVICE_ATTR_RO(temp2_input, temp, 1);
static SENSOR_DEVICE_ATTR_RO(temp3_input, temp, 2);

static SENSOR_DEVICE_ATTR_RO(temp1_max, temp, 3);
static SENSOR_DEVICE_ATTR_RO(temp2_max, temp, 4);
static SENSOR_DEVICE_ATTR_RO(temp3_max, temp, 5);

static SENSOR_DEVICE_ATTR_RO(temp1_min, temp, 6);
static SENSOR_DEVICE_ATTR_RO(temp2_min, temp, 7);
static SENSOR_DEVICE_ATTR_RO(temp3_min, temp, 8);

static SENSOR_DEVICE_ATTR_RO(fan1_input, fan, 0);
static SENSOR_DEVICE_ATTR_RO(fan2_input, fan, 1);

static SENSOR_DEVICE_ATTR_RO(fan1_min, fan, 2);
static SENSOR_DEVICE_ATTR_RO(fan2_min, fan, 3);

static SENSOR_DEVICE_ATTR_RW(fan1_div, fan_div, 0);
static SENSOR_DEVICE_ATTR_RW(fan2_div, fan_div, 1);

static struct attribute *adm1029_attrs[] = {
        &sensor_dev_attr_temp1_input.dev_attr.attr,
        &sensor_dev_attr_temp1_min.dev_attr.attr,
        &sensor_dev_attr_temp1_max.dev_attr.attr,
        &sensor_dev_attr_temp2_input.dev_attr.attr,
        &sensor_dev_attr_temp2_min.dev_attr.attr,
        &sensor_dev_attr_temp2_max.dev_attr.attr,
        &sensor_dev_attr_temp3_input.dev_attr.attr,
        &sensor_dev_attr_temp3_min.dev_attr.attr,
        &sensor_dev_attr_temp3_max.dev_attr.attr,
        &sensor_dev_attr_fan1_input.dev_attr.attr,
        &sensor_dev_attr_fan2_input.dev_attr.attr,
        &sensor_dev_attr_fan1_min.dev_attr.attr,
        &sensor_dev_attr_fan2_min.dev_attr.attr,
        &sensor_dev_attr_fan1_div.dev_attr.attr,
        &sensor_dev_attr_fan2_div.dev_attr.attr,
        NULL
};

ATTRIBUTE_GROUPS(adm1029);

/*
 * Real code
 */

/* Return 0 if detection is successful, -ENODEV otherwise */
static int adm1029_detect(struct i2c_client *client,
                          struct i2c_board_info *info)
{
        struct i2c_adapter *adapter = client->adapter;
        u8 man_id, chip_id, temp_devices_installed, nb_fan_support;

        if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
                return -ENODEV;

        /*
         * ADM1029 doesn't have CHIP ID, check just MAN ID
         * For better detection we check also ADM1029_TEMP_DEVICES_INSTALLED,
         * ADM1029_REG_NB_FAN_SUPPORT and compare it with possible values
         * documented
         */

        man_id = i2c_smbus_read_byte_data(client, ADM1029_REG_MAN_ID);
        chip_id = i2c_smbus_read_byte_data(client, ADM1029_REG_CHIP_ID);
        temp_devices_installed = i2c_smbus_read_byte_data(client,
                                        ADM1029_REG_TEMP_DEVICES_INSTALLED);
        nb_fan_support = i2c_smbus_read_byte_data(client,
                                                  ADM1029_REG_NB_FAN_SUPPORT);
        /* 0x41 is Analog Devices */
        if (man_id != 0x41 || (temp_devices_installed & 0xf9) != 0x01 ||
            nb_fan_support != 0x03)
                return -ENODEV;

        if ((chip_id & 0xF0) != 0x00) {
                /*
                 * There are no "official" CHIP ID, so actually
                 * we use Major/Minor revision for that
                 */
                pr_info("Unknown major revision %x, please let us know\n",
                        chip_id);
                return -ENODEV;
        }

        strscpy(info->type, "adm1029", I2C_NAME_SIZE);

        return 0;
}

static int adm1029_init_client(struct i2c_client *client)
{
        u8 config;

        config = i2c_smbus_read_byte_data(client, ADM1029_REG_CONFIG);
        if ((config & 0x10) == 0) {
                i2c_smbus_write_byte_data(client, ADM1029_REG_CONFIG,
                                          config | 0x10);
        }
        /* recheck config */
        config = i2c_smbus_read_byte_data(client, ADM1029_REG_CONFIG);
        if ((config & 0x10) == 0) {
                dev_err(&client->dev, "Initialization failed!\n");
                return 0;
        }
        return 1;
}

static int adm1029_probe(struct i2c_client *client)
{
        struct device *dev = &client->dev;
        struct adm1029_data *data;
        struct device *hwmon_dev;

        data = devm_kzalloc(dev, sizeof(struct adm1029_data), GFP_KERNEL);
        if (!data)
                return -ENOMEM;

        data->client = client;
        mutex_init(&data->update_lock);

        /*
         * Initialize the ADM1029 chip
         * Check config register
         */
        if (adm1029_init_client(client) == 0)
                return -ENODEV;

        hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
                                                           data,
                                                           adm1029_groups);
        return PTR_ERR_OR_ZERO(hwmon_dev);
}

static const struct i2c_device_id adm1029_id[] = {
        { "adm1029" },
        { }
};
MODULE_DEVICE_TABLE(i2c, adm1029_id);

static struct i2c_driver adm1029_driver = {
        .class          = I2C_CLASS_HWMON,
        .driver = {
                .name = "adm1029",
        },
        .probe          = adm1029_probe,
        .id_table       = adm1029_id,
        .detect         = adm1029_detect,
        .address_list   = normal_i2c,
};

module_i2c_driver(adm1029_driver);

MODULE_AUTHOR("Corentin LABBE <clabbe.montjoie@gmail.com>");
MODULE_DESCRIPTION("adm1029 driver");
MODULE_LICENSE("GPL v2");