// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * tps65910.c  --  TI TPS6591x
 *
 * Copyright 2010 Texas Instruments Inc.
 *
 * Author: Jorge Eduardo Candelaria <jedu@slimlogic.co.uk>
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/err.h>
#include <linux/platform_device.h>
#include <linux/debugfs.h>
#include <linux/gpio.h>
#include <linux/mfd/tps65910.h>

#define COMP1                                   0
#define COMP2                                   1

/* Comparator 1 voltage selection table in millivolts */
static const u16 COMP_VSEL_TABLE[] = {
        0, 2500, 2500, 2500, 2500, 2550, 2600, 2650,
        2700, 2750, 2800, 2850, 2900, 2950, 3000, 3050,
        3100, 3150, 3200, 3250, 3300, 3350, 3400, 3450,
        3500,
};

struct comparator {
        const char *name;
        int reg;
        int uV_max;
        const u16 *vsel_table;
};

static struct comparator tps_comparators[] = {
        {
                .name = "COMP1",
                .reg = TPS65911_VMBCH,
                .uV_max = 3500,
                .vsel_table = COMP_VSEL_TABLE,
        },
        {
                .name = "COMP2",
                .reg = TPS65911_VMBCH2,
                .uV_max = 3500,
                .vsel_table = COMP_VSEL_TABLE,
        },
};

static int comp_threshold_set(struct tps65910 *tps65910, int id, int voltage)
{
        struct comparator tps_comp = tps_comparators[id];
        int curr_voltage = 0;
        int ret;
        u8 index = 0, val;

        while (curr_voltage < tps_comp.uV_max) {
                curr_voltage = tps_comp.vsel_table[index];
                if (curr_voltage >= voltage)
                        break;
                else if (curr_voltage < voltage)
                        index ++;
        }

        if (curr_voltage > tps_comp.uV_max)
                return -EINVAL;

        val = index << 1;
        ret = regmap_write(tps65910->regmap, tps_comp.reg, val);

        return ret;
}

static int comp_threshold_get(struct tps65910 *tps65910, int id)
{
        struct comparator tps_comp = tps_comparators[id];
        unsigned int val;
        int ret;

        ret = regmap_read(tps65910->regmap, tps_comp.reg, &val);
        if (ret < 0)
                return ret;

        val >>= 1;
        return tps_comp.vsel_table[val];
}

static ssize_t comp_threshold_show(struct device *dev,
                                struct device_attribute *attr, char *buf)
{
        struct tps65910 *tps65910 = dev_get_drvdata(dev->parent);
        struct attribute comp_attr = attr->attr;
        int id, uVolt;

        if (!strcmp(comp_attr.name, "comp1_threshold"))
                id = COMP1;
        else if (!strcmp(comp_attr.name, "comp2_threshold"))
                id = COMP2;
        else
                return -EINVAL;

        uVolt = comp_threshold_get(tps65910, id);

        return sprintf(buf, "%d\n", uVolt);
}

static DEVICE_ATTR(comp1_threshold, S_IRUGO, comp_threshold_show, NULL);
static DEVICE_ATTR(comp2_threshold, S_IRUGO, comp_threshold_show, NULL);

static int tps65911_comparator_probe(struct platform_device *pdev)
{
        struct tps65910 *tps65910 = dev_get_drvdata(pdev->dev.parent);
        struct tps65910_board *pdata = dev_get_platdata(tps65910->dev);
        int ret;

        ret = comp_threshold_set(tps65910, COMP1,  pdata->vmbch_threshold);
        if (ret < 0) {
                dev_err(&pdev->dev, "cannot set COMP1 threshold\n");
                return ret;
        }

        ret = comp_threshold_set(tps65910, COMP2, pdata->vmbch2_threshold);
        if (ret < 0) {
                dev_err(&pdev->dev, "cannot set COMP2 threshold\n");
                return ret;
        }

        /* Create sysfs entry */
        ret = device_create_file(&pdev->dev, &dev_attr_comp1_threshold);
        if (ret < 0)
                dev_err(&pdev->dev, "failed to add COMP1 sysfs file\n");

        ret = device_create_file(&pdev->dev, &dev_attr_comp2_threshold);
        if (ret < 0)
                dev_err(&pdev->dev, "failed to add COMP2 sysfs file\n");

        return ret;
}

static void tps65911_comparator_remove(struct platform_device *pdev)
{
        struct tps65910 *tps65910;

        tps65910 = dev_get_drvdata(pdev->dev.parent);
        device_remove_file(&pdev->dev, &dev_attr_comp2_threshold);
        device_remove_file(&pdev->dev, &dev_attr_comp1_threshold);
}

static struct platform_driver tps65911_comparator_driver = {
        .driver = {
                .name = "tps65911-comparator",
        },
        .probe = tps65911_comparator_probe,
        .remove = tps65911_comparator_remove,
};

static int __init tps65911_comparator_init(void)
{
        return platform_driver_register(&tps65911_comparator_driver);
}
subsys_initcall(tps65911_comparator_init);

static void __exit tps65911_comparator_exit(void)
{
        platform_driver_unregister(&tps65911_comparator_driver);
}
module_exit(tps65911_comparator_exit);

MODULE_AUTHOR("Jorge Eduardo Candelaria <jedu@slimlogic.co.uk>");
MODULE_DESCRIPTION("TPS65911 comparator driver");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:tps65911-comparator");