// SPDX-License-Identifier: GPL-2.0-only
/*
 * An hwmon driver for the Analog Devices AD7416/17/18
 * Copyright (C) 2006-07 Tower Technologies
 *
 * Author: Alessandro Zummo <a.zummo@towertech.it>
 *
 * Based on lm75.c
 * Copyright (C) 1998-99 Frodo Looijaard <frodol@dds.nl>
 */

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

#include "lm75.h"

#define DRV_VERSION "0.4"

enum chips { ad7416, ad7417, ad7418 };

/* AD7418 registers */
#define AD7418_REG_TEMP_IN      0x00
#define AD7418_REG_CONF         0x01
#define AD7418_REG_TEMP_HYST    0x02
#define AD7418_REG_TEMP_OS      0x03
#define AD7418_REG_ADC          0x04
#define AD7418_REG_CONF2        0x05

#define AD7418_REG_ADC_CH(x)    ((x) << 5)
#define AD7418_CH_TEMP          AD7418_REG_ADC_CH(0)

static const u8 AD7418_REG_TEMP[] = { AD7418_REG_TEMP_IN,
                                        AD7418_REG_TEMP_HYST,
                                        AD7418_REG_TEMP_OS };

struct ad7418_data {
        struct i2c_client       *client;
        enum chips              type;
        struct mutex            lock;
        int                     adc_max;        /* number of ADC channels */
        bool                    valid;
        unsigned long           last_updated;   /* In jiffies */
        s16                     temp[3];        /* Register values */
        u16                     in[4];
};

static int ad7418_update_device(struct device *dev)
{
        struct ad7418_data *data = dev_get_drvdata(dev);
        struct i2c_client *client = data->client;
        s32 val;

        mutex_lock(&data->lock);

        if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
                || !data->valid) {
                u8 cfg;
                int i, ch;

                /* read config register and clear channel bits */
                val = i2c_smbus_read_byte_data(client, AD7418_REG_CONF);
                if (val < 0)
                        goto abort;

                cfg = val;
                cfg &= 0x1F;

                val = i2c_smbus_write_byte_data(client, AD7418_REG_CONF,
                                                cfg | AD7418_CH_TEMP);
                if (val < 0)
                        goto abort;

                udelay(30);

                for (i = 0; i < 3; i++) {
                        val = i2c_smbus_read_word_swapped(client,
                                                          AD7418_REG_TEMP[i]);
                        if (val < 0)
                                goto abort;

                        data->temp[i] = val;
                }

                for (i = 0, ch = 4; i < data->adc_max; i++, ch--) {
                        val = i2c_smbus_write_byte_data(client, AD7418_REG_CONF,
                                        cfg | AD7418_REG_ADC_CH(ch));
                        if (val < 0)
                                goto abort;

                        udelay(15);
                        val = i2c_smbus_read_word_swapped(client,
                                                          AD7418_REG_ADC);
                        if (val < 0)
                                goto abort;

                        data->in[data->adc_max - 1 - i] = val;
                }

                /* restore old configuration value */
                val = i2c_smbus_write_word_swapped(client, AD7418_REG_CONF,
                                                   cfg);
                if (val < 0)
                        goto abort;

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

        mutex_unlock(&data->lock);
        return 0;

abort:
        data->valid = false;
        mutex_unlock(&data->lock);
        return val;
}

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 ad7418_data *data = dev_get_drvdata(dev);
        int ret;

        ret = ad7418_update_device(dev);
        if (ret < 0)
                return ret;

        return sprintf(buf, "%d\n",
                LM75_TEMP_FROM_REG(data->temp[attr->index]));
}

static ssize_t adc_show(struct device *dev, struct device_attribute *devattr,
                        char *buf)
{
        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
        struct ad7418_data *data = dev_get_drvdata(dev);
        int ret;

        ret = ad7418_update_device(dev);
        if (ret < 0)
                return ret;

        return sprintf(buf, "%d\n",
                ((data->in[attr->index] >> 6) * 2500 + 512) / 1024);
}

static ssize_t temp_store(struct device *dev,
                          struct device_attribute *devattr, const char *buf,
                          size_t count)
{
        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
        struct ad7418_data *data = dev_get_drvdata(dev);
        struct i2c_client *client = data->client;
        long temp;
        int ret = kstrtol(buf, 10, &temp);

        if (ret < 0)
                return ret;

        mutex_lock(&data->lock);
        data->temp[attr->index] = LM75_TEMP_TO_REG(temp);
        i2c_smbus_write_word_swapped(client,
                                     AD7418_REG_TEMP[attr->index],
                                     data->temp[attr->index]);
        mutex_unlock(&data->lock);
        return count;
}

static SENSOR_DEVICE_ATTR_RO(temp1_input, temp, 0);
static SENSOR_DEVICE_ATTR_RW(temp1_max_hyst, temp, 1);
static SENSOR_DEVICE_ATTR_RW(temp1_max, temp, 2);

static SENSOR_DEVICE_ATTR_RO(in1_input, adc, 0);
static SENSOR_DEVICE_ATTR_RO(in2_input, adc, 1);
static SENSOR_DEVICE_ATTR_RO(in3_input, adc, 2);
static SENSOR_DEVICE_ATTR_RO(in4_input, adc, 3);

static struct attribute *ad7416_attrs[] = {
        &sensor_dev_attr_temp1_max.dev_attr.attr,
        &sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
        &sensor_dev_attr_temp1_input.dev_attr.attr,
        NULL
};
ATTRIBUTE_GROUPS(ad7416);

static struct attribute *ad7417_attrs[] = {
        &sensor_dev_attr_temp1_max.dev_attr.attr,
        &sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
        &sensor_dev_attr_temp1_input.dev_attr.attr,
        &sensor_dev_attr_in1_input.dev_attr.attr,
        &sensor_dev_attr_in2_input.dev_attr.attr,
        &sensor_dev_attr_in3_input.dev_attr.attr,
        &sensor_dev_attr_in4_input.dev_attr.attr,
        NULL
};
ATTRIBUTE_GROUPS(ad7417);

static struct attribute *ad7418_attrs[] = {
        &sensor_dev_attr_temp1_max.dev_attr.attr,
        &sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
        &sensor_dev_attr_temp1_input.dev_attr.attr,
        &sensor_dev_attr_in1_input.dev_attr.attr,
        NULL
};
ATTRIBUTE_GROUPS(ad7418);

static void ad7418_init_client(struct i2c_client *client)
{
        struct ad7418_data *data = i2c_get_clientdata(client);

        int reg = i2c_smbus_read_byte_data(client, AD7418_REG_CONF);
        if (reg < 0) {
                dev_err(&client->dev, "cannot read configuration register\n");
        } else {
                dev_info(&client->dev, "configuring for mode 1\n");
                i2c_smbus_write_byte_data(client, AD7418_REG_CONF, reg & 0xfe);

                if (data->type == ad7417 || data->type == ad7418)
                        i2c_smbus_write_byte_data(client,
                                                AD7418_REG_CONF2, 0x00);
        }
}

static int ad7418_probe(struct i2c_client *client)
{
        struct device *dev = &client->dev;
        struct i2c_adapter *adapter = client->adapter;
        struct ad7418_data *data;
        struct device *hwmon_dev;
        const struct attribute_group **attr_groups = NULL;

        if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
                                        I2C_FUNC_SMBUS_WORD_DATA))
                return -EOPNOTSUPP;

        data = devm_kzalloc(dev, sizeof(struct ad7418_data), GFP_KERNEL);
        if (!data)
                return -ENOMEM;

        i2c_set_clientdata(client, data);

        mutex_init(&data->lock);
        data->client = client;
        data->type = (uintptr_t)i2c_get_match_data(client);

        switch (data->type) {
        case ad7416:
                data->adc_max = 0;
                attr_groups = ad7416_groups;
                break;

        case ad7417:
                data->adc_max = 4;
                attr_groups = ad7417_groups;
                break;

        case ad7418:
                data->adc_max = 1;
                attr_groups = ad7418_groups;
                break;
        }

        dev_info(dev, "%s chip found\n", client->name);

        /* Initialize the AD7418 chip */
        ad7418_init_client(client);

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

static const struct i2c_device_id ad7418_id[] = {
        { "ad7416", ad7416 },
        { "ad7417", ad7417 },
        { "ad7418", ad7418 },
        { }
};
MODULE_DEVICE_TABLE(i2c, ad7418_id);

static const struct of_device_id ad7418_dt_ids[] = {
        { .compatible = "adi,ad7416", .data = (void *)ad7416, },
        { .compatible = "adi,ad7417", .data = (void *)ad7417, },
        { .compatible = "adi,ad7418", .data = (void *)ad7418, },
        { }
};
MODULE_DEVICE_TABLE(of, ad7418_dt_ids);

static struct i2c_driver ad7418_driver = {
        .driver = {
                .name   = "ad7418",
                .of_match_table = ad7418_dt_ids,
        },
        .probe          = ad7418_probe,
        .id_table       = ad7418_id,
};

module_i2c_driver(ad7418_driver);

MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
MODULE_DESCRIPTION("AD7416/17/18 driver");
MODULE_LICENSE("GPL");
MODULE_VERSION(DRV_VERSION);