// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * ADT7310/ADT7310 digital temperature sensor driver
 *
 * Copyright 2012-2013 Analog Devices Inc.
 *   Author: Lars-Peter Clausen <lars@metafoo.de>
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/regmap.h>
#include <linux/spi/spi.h>
#include <linux/unaligned.h>

#include "adt7x10.h"

#define ADT7310_STATUS                  0
#define ADT7310_CONFIG                  1
#define ADT7310_TEMPERATURE             2
#define ADT7310_ID                      3
#define ADT7310_T_CRIT                  4
#define ADT7310_T_HYST                  5
#define ADT7310_T_ALARM_HIGH            6
#define ADT7310_T_ALARM_LOW             7

static const u8 adt7310_reg_table[] = {
        [ADT7X10_TEMPERATURE]   = ADT7310_TEMPERATURE,
        [ADT7X10_STATUS]        = ADT7310_STATUS,
        [ADT7X10_CONFIG]        = ADT7310_CONFIG,
        [ADT7X10_T_ALARM_HIGH]  = ADT7310_T_ALARM_HIGH,
        [ADT7X10_T_ALARM_LOW]   = ADT7310_T_ALARM_LOW,
        [ADT7X10_T_CRIT]        = ADT7310_T_CRIT,
        [ADT7X10_T_HYST]        = ADT7310_T_HYST,
        [ADT7X10_ID]            = ADT7310_ID,
};

#define ADT7310_CMD_REG_OFFSET  3
#define ADT7310_CMD_READ        0x40

#define AD7310_COMMAND(reg) (adt7310_reg_table[(reg)] << ADT7310_CMD_REG_OFFSET)

static int adt7310_spi_read_word(struct spi_device *spi, u8 reg)
{
        return spi_w8r16be(spi, AD7310_COMMAND(reg) | ADT7310_CMD_READ);
}

static int adt7310_spi_write_word(struct spi_device *spi, u8 reg, u16 data)
{
        u8 buf[3];

        buf[0] = AD7310_COMMAND(reg);
        put_unaligned_be16(data, &buf[1]);

        return spi_write(spi, buf, sizeof(buf));
}

static int adt7310_spi_read_byte(struct spi_device *spi, u8 reg)
{
        return spi_w8r8(spi, AD7310_COMMAND(reg) | ADT7310_CMD_READ);
}

static int adt7310_spi_write_byte(struct spi_device *spi, u8 reg, u8 data)
{
        u8 buf[2];

        buf[0] = AD7310_COMMAND(reg);
        buf[1] = data;

        return spi_write(spi, buf, sizeof(buf));
}

static bool adt7310_regmap_is_volatile(struct device *dev, unsigned int reg)
{
        switch (reg) {
        case ADT7X10_TEMPERATURE:
        case ADT7X10_STATUS:
                return true;
        default:
                return false;
        }
}

static int adt7310_reg_read(void *context, unsigned int reg, unsigned int *val)
{
        struct spi_device *spi = context;
        int regval;

        switch (reg) {
        case ADT7X10_TEMPERATURE:
        case ADT7X10_T_ALARM_HIGH:
        case ADT7X10_T_ALARM_LOW:
        case ADT7X10_T_CRIT:
                regval = adt7310_spi_read_word(spi, reg);
                break;
        default:
                regval = adt7310_spi_read_byte(spi, reg);
                break;
        }
        if (regval < 0)
                return regval;
        *val = regval;
        return 0;
}

static int adt7310_reg_write(void *context, unsigned int reg, unsigned int val)
{
        struct spi_device *spi = context;
        int ret;

        switch (reg) {
        case ADT7X10_TEMPERATURE:
        case ADT7X10_T_ALARM_HIGH:
        case ADT7X10_T_ALARM_LOW:
        case ADT7X10_T_CRIT:
                ret = adt7310_spi_write_word(spi, reg, val);
                break;
        default:
                ret = adt7310_spi_write_byte(spi, reg, val);
                break;
        }
        return ret;
}

static const struct regmap_config adt7310_regmap_config = {
        .reg_bits = 8,
        .val_bits = 16,
        .cache_type = REGCACHE_MAPLE,
        .volatile_reg = adt7310_regmap_is_volatile,
        .reg_read = adt7310_reg_read,
        .reg_write = adt7310_reg_write,
};

static int adt7310_spi_probe(struct spi_device *spi)
{
        struct regmap *regmap;

        regmap = devm_regmap_init(&spi->dev, NULL, spi, &adt7310_regmap_config);
        if (IS_ERR(regmap))
                return PTR_ERR(regmap);

        return adt7x10_probe(&spi->dev, spi_get_device_id(spi)->name, spi->irq,
                             regmap);
}

static const struct spi_device_id adt7310_id[] = {
        { "adt7310", 0 },
        { "adt7320", 0 },
        {}
};
MODULE_DEVICE_TABLE(spi, adt7310_id);

static struct spi_driver adt7310_driver = {
        .driver = {
                .name   = "adt7310",
                .pm     = pm_sleep_ptr(&adt7x10_dev_pm_ops),
        },
        .probe          = adt7310_spi_probe,
        .id_table       = adt7310_id,
};
module_spi_driver(adt7310_driver);

MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
MODULE_DESCRIPTION("ADT7310/ADT7320 driver");
MODULE_LICENSE("GPL");