/*
 * 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.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#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_device.h>
#include <linux/regmap.h>
#include <linux/slab.h>

static 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_RBTREE,
};

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_RBTREE,
};

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,
				       const struct i2c_device_id *id)
{
	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;
	dev_set_drvdata(max8907->dev, max8907);

	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(i2c->adapter, MAX8907_RTC_I2C_ADDR);
	if (!max8907->i2c_rtc) {
		ret = -ENOMEM;
		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;
	}

	irq_set_status_flags(max8907->i2c_gen->irq, IRQ_NOAUTOEN);

	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;
	}

	enable_irq(max8907->i2c_gen->irq);

	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 int 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);

	return 0;
}

#ifdef CONFIG_OF
static 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", 0},
	{}
};
MODULE_DEVICE_TABLE(i2c, max8907_i2c_id);

static struct i2c_driver max8907_i2c_driver = {
	.driver = {
		.name = "max8907",
		.owner = THIS_MODULE,
		.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");