root/drivers/mfd/max8907.c
// SPDX-License-Identifier: GPL-2.0-only
/*
 * max8907.c - mfd driver for MAX8907
 *
 * Copyright (C) 2010 Gyungoh Yoo <jack.yoo@maxim-ic.com>
 * Copyright (C) 2010-2012, NVIDIA CORPORATION. All rights reserved.
 */

#include <linux/err.h>
#include <linux/i2c.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/mfd/core.h>
#include <linux/mfd/max8907.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/regmap.h>
#include <linux/slab.h>

static const struct mfd_cell max8907_cells[] = {
        { .name = "max8907-regulator", },
        { .name = "max8907-rtc", },
};

static bool max8907_gen_is_volatile_reg(struct device *dev, unsigned int reg)
{
        switch (reg) {
        case MAX8907_REG_ON_OFF_IRQ1:
        case MAX8907_REG_ON_OFF_STAT:
        case MAX8907_REG_ON_OFF_IRQ2:
        case MAX8907_REG_CHG_IRQ1:
        case MAX8907_REG_CHG_IRQ2:
        case MAX8907_REG_CHG_STAT:
                return true;
        default:
                return false;
        }
}

static bool max8907_gen_is_precious_reg(struct device *dev, unsigned int reg)
{
        switch (reg) {
        case MAX8907_REG_ON_OFF_IRQ1:
        case MAX8907_REG_ON_OFF_IRQ2:
        case MAX8907_REG_CHG_IRQ1:
        case MAX8907_REG_CHG_IRQ2:
                return true;
        default:
                return false;
        }
}

static bool max8907_gen_is_writeable_reg(struct device *dev, unsigned int reg)
{
        return !max8907_gen_is_volatile_reg(dev, reg);
}

static const struct regmap_config max8907_regmap_gen_config = {
        .reg_bits = 8,
        .val_bits = 8,
        .volatile_reg = max8907_gen_is_volatile_reg,
        .precious_reg = max8907_gen_is_precious_reg,
        .writeable_reg = max8907_gen_is_writeable_reg,
        .max_register = MAX8907_REG_LDO20VOUT,
        .cache_type = REGCACHE_MAPLE,
};

static bool max8907_rtc_is_volatile_reg(struct device *dev, unsigned int reg)
{
        if (reg <= MAX8907_REG_RTC_YEAR2)
                return true;

        switch (reg) {
        case MAX8907_REG_RTC_STATUS:
        case MAX8907_REG_RTC_IRQ:
                return true;
        default:
                return false;
        }
}

static bool max8907_rtc_is_precious_reg(struct device *dev, unsigned int reg)
{
        switch (reg) {
        case MAX8907_REG_RTC_IRQ:
                return true;
        default:
                return false;
        }
}

static bool max8907_rtc_is_writeable_reg(struct device *dev, unsigned int reg)
{
        switch (reg) {
        case MAX8907_REG_RTC_STATUS:
        case MAX8907_REG_RTC_IRQ:
                return false;
        default:
                return true;
        }
}

static const struct regmap_config max8907_regmap_rtc_config = {
        .reg_bits = 8,
        .val_bits = 8,
        .volatile_reg = max8907_rtc_is_volatile_reg,
        .precious_reg = max8907_rtc_is_precious_reg,
        .writeable_reg = max8907_rtc_is_writeable_reg,
        .max_register = MAX8907_REG_MPL_CNTL,
        .cache_type = REGCACHE_MAPLE,
};

static const struct regmap_irq max8907_chg_irqs[] = {
        { .reg_offset = 0, .mask = 1 << 0, },
        { .reg_offset = 0, .mask = 1 << 1, },
        { .reg_offset = 0, .mask = 1 << 2, },
        { .reg_offset = 1, .mask = 1 << 0, },
        { .reg_offset = 1, .mask = 1 << 1, },
        { .reg_offset = 1, .mask = 1 << 2, },
        { .reg_offset = 1, .mask = 1 << 3, },
        { .reg_offset = 1, .mask = 1 << 4, },
        { .reg_offset = 1, .mask = 1 << 5, },
        { .reg_offset = 1, .mask = 1 << 6, },
        { .reg_offset = 1, .mask = 1 << 7, },
};

static const struct regmap_irq_chip max8907_chg_irq_chip = {
        .name = "max8907 chg",
        .status_base = MAX8907_REG_CHG_IRQ1,
        .mask_base = MAX8907_REG_CHG_IRQ1_MASK,
        .wake_base = MAX8907_REG_CHG_IRQ1_MASK,
        .irq_reg_stride = MAX8907_REG_CHG_IRQ2 - MAX8907_REG_CHG_IRQ1,
        .num_regs = 2,
        .irqs = max8907_chg_irqs,
        .num_irqs = ARRAY_SIZE(max8907_chg_irqs),
};

static const struct regmap_irq max8907_on_off_irqs[] = {
        { .reg_offset = 0, .mask = 1 << 0, },
        { .reg_offset = 0, .mask = 1 << 1, },
        { .reg_offset = 0, .mask = 1 << 2, },
        { .reg_offset = 0, .mask = 1 << 3, },
        { .reg_offset = 0, .mask = 1 << 4, },
        { .reg_offset = 0, .mask = 1 << 5, },
        { .reg_offset = 0, .mask = 1 << 6, },
        { .reg_offset = 0, .mask = 1 << 7, },
        { .reg_offset = 1, .mask = 1 << 0, },
        { .reg_offset = 1, .mask = 1 << 1, },
};

static const struct regmap_irq_chip max8907_on_off_irq_chip = {
        .name = "max8907 on_off",
        .status_base = MAX8907_REG_ON_OFF_IRQ1,
        .mask_base = MAX8907_REG_ON_OFF_IRQ1_MASK,
        .irq_reg_stride = MAX8907_REG_ON_OFF_IRQ2 - MAX8907_REG_ON_OFF_IRQ1,
        .num_regs = 2,
        .irqs = max8907_on_off_irqs,
        .num_irqs = ARRAY_SIZE(max8907_on_off_irqs),
};

static const struct regmap_irq max8907_rtc_irqs[] = {
        { .reg_offset = 0, .mask = 1 << 2, },
        { .reg_offset = 0, .mask = 1 << 3, },
};

static const struct regmap_irq_chip max8907_rtc_irq_chip = {
        .name = "max8907 rtc",
        .status_base = MAX8907_REG_RTC_IRQ,
        .mask_base = MAX8907_REG_RTC_IRQ_MASK,
        .num_regs = 1,
        .irqs = max8907_rtc_irqs,
        .num_irqs = ARRAY_SIZE(max8907_rtc_irqs),
};

static struct max8907 *max8907_pm_off;
static void max8907_power_off(void)
{
        regmap_update_bits(max8907_pm_off->regmap_gen, MAX8907_REG_RESET_CNFG,
                        MAX8907_MASK_POWER_OFF, MAX8907_MASK_POWER_OFF);
}

static int max8907_i2c_probe(struct i2c_client *i2c)
{
        struct max8907 *max8907;
        int ret;
        struct max8907_platform_data *pdata = dev_get_platdata(&i2c->dev);
        bool pm_off = false;

        if (pdata)
                pm_off = pdata->pm_off;
        else if (i2c->dev.of_node)
                pm_off = of_property_read_bool(i2c->dev.of_node,
                                        "maxim,system-power-controller");

        max8907 = devm_kzalloc(&i2c->dev, sizeof(struct max8907), GFP_KERNEL);
        if (!max8907) {
                ret = -ENOMEM;
                goto err_alloc_drvdata;
        }

        max8907->dev = &i2c->dev;
        max8907->i2c_gen = i2c;
        i2c_set_clientdata(i2c, max8907);
        max8907->regmap_gen = devm_regmap_init_i2c(i2c,
                                                &max8907_regmap_gen_config);
        if (IS_ERR(max8907->regmap_gen)) {
                ret = PTR_ERR(max8907->regmap_gen);
                dev_err(&i2c->dev, "gen regmap init failed: %d\n", ret);
                goto err_regmap_gen;
        }

        max8907->i2c_rtc = i2c_new_dummy_device(i2c->adapter, MAX8907_RTC_I2C_ADDR);
        if (IS_ERR(max8907->i2c_rtc)) {
                ret = PTR_ERR(max8907->i2c_rtc);
                goto err_dummy_rtc;
        }
        i2c_set_clientdata(max8907->i2c_rtc, max8907);
        max8907->regmap_rtc = devm_regmap_init_i2c(max8907->i2c_rtc,
                                                &max8907_regmap_rtc_config);
        if (IS_ERR(max8907->regmap_rtc)) {
                ret = PTR_ERR(max8907->regmap_rtc);
                dev_err(&i2c->dev, "rtc regmap init failed: %d\n", ret);
                goto err_regmap_rtc;
        }

        ret = regmap_add_irq_chip(max8907->regmap_gen, max8907->i2c_gen->irq,
                                  IRQF_ONESHOT | IRQF_SHARED,
                                  -1, &max8907_chg_irq_chip,
                                  &max8907->irqc_chg);
        if (ret != 0) {
                dev_err(&i2c->dev, "failed to add chg irq chip: %d\n", ret);
                goto err_irqc_chg;
        }
        ret = regmap_add_irq_chip(max8907->regmap_gen, max8907->i2c_gen->irq,
                                  IRQF_ONESHOT | IRQF_SHARED, -1,
                                  &max8907_on_off_irq_chip,
                                  &max8907->irqc_on_off);
        if (ret != 0) {
                dev_err(&i2c->dev, "failed to add on off irq chip: %d\n", ret);
                goto err_irqc_on_off;
        }
        ret = regmap_add_irq_chip(max8907->regmap_rtc, max8907->i2c_gen->irq,
                                  IRQF_ONESHOT | IRQF_SHARED, -1,
                                  &max8907_rtc_irq_chip,
                                  &max8907->irqc_rtc);
        if (ret != 0) {
                dev_err(&i2c->dev, "failed to add rtc irq chip: %d\n", ret);
                goto err_irqc_rtc;
        }

        ret = mfd_add_devices(max8907->dev, -1, max8907_cells,
                              ARRAY_SIZE(max8907_cells), NULL, 0, NULL);
        if (ret != 0) {
                dev_err(&i2c->dev, "failed to add MFD devices %d\n", ret);
                goto err_add_devices;
        }

        if (pm_off && !pm_power_off) {
                max8907_pm_off = max8907;
                pm_power_off = max8907_power_off;
        }

        return 0;

err_add_devices:
        regmap_del_irq_chip(max8907->i2c_gen->irq, max8907->irqc_rtc);
err_irqc_rtc:
        regmap_del_irq_chip(max8907->i2c_gen->irq, max8907->irqc_on_off);
err_irqc_on_off:
        regmap_del_irq_chip(max8907->i2c_gen->irq, max8907->irqc_chg);
err_irqc_chg:
err_regmap_rtc:
        i2c_unregister_device(max8907->i2c_rtc);
err_dummy_rtc:
err_regmap_gen:
err_alloc_drvdata:
        return ret;
}

static void max8907_i2c_remove(struct i2c_client *i2c)
{
        struct max8907 *max8907 = i2c_get_clientdata(i2c);

        mfd_remove_devices(max8907->dev);

        regmap_del_irq_chip(max8907->i2c_gen->irq, max8907->irqc_rtc);
        regmap_del_irq_chip(max8907->i2c_gen->irq, max8907->irqc_on_off);
        regmap_del_irq_chip(max8907->i2c_gen->irq, max8907->irqc_chg);

        i2c_unregister_device(max8907->i2c_rtc);
}

#ifdef CONFIG_OF
static const struct of_device_id max8907_of_match[] = {
        { .compatible = "maxim,max8907" },
        { },
};
MODULE_DEVICE_TABLE(of, max8907_of_match);
#endif

static const struct i2c_device_id max8907_i2c_id[] = {
        { "max8907" },
        {}
};
MODULE_DEVICE_TABLE(i2c, max8907_i2c_id);

static struct i2c_driver max8907_i2c_driver = {
        .driver = {
                .name = "max8907",
                .of_match_table = of_match_ptr(max8907_of_match),
        },
        .probe = max8907_i2c_probe,
        .remove = max8907_i2c_remove,
        .id_table = max8907_i2c_id,
};

static int __init max8907_i2c_init(void)
{
        int ret = -ENODEV;

        ret = i2c_add_driver(&max8907_i2c_driver);
        if (ret != 0)
                pr_err("Failed to register I2C driver: %d\n", ret);

        return ret;
}
subsys_initcall(max8907_i2c_init);

static void __exit max8907_i2c_exit(void)
{
        i2c_del_driver(&max8907_i2c_driver);
}
module_exit(max8907_i2c_exit);

MODULE_DESCRIPTION("MAX8907 multi-function core driver");
MODULE_AUTHOR("Gyungoh Yoo <jack.yoo@maxim-ic.com>");
MODULE_LICENSE("GPL v2");