/*
 * Core driver for TI TPS6586x PMIC family
 *
 * Copyright (c) 2010 CompuLab Ltd.
 * Mike Rapoport <mike@compulab.co.il>
 *
 * Based on da903x.c.
 * Copyright (C) 2008 Compulab, Ltd.
 * Mike Rapoport <mike@compulab.co.il>
 * Copyright (C) 2006-2008 Marvell International Ltd.
 * Eric Miao <eric.miao@marvell.com>
 *
 * 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/interrupt.h>
#include <linux/irq.h>
#include <linux/irqdomain.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/slab.h>
#include <linux/err.h>
#include <linux/i2c.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>

#include <linux/mfd/core.h>
#include <linux/mfd/tps6586x.h>

#define TPS6586X_SUPPLYENE	0x14
#define EXITSLREQ_BIT		BIT(1)
#define SLEEP_MODE_BIT		BIT(3)

/* interrupt control registers */
#define TPS6586X_INT_ACK1	0xb5
#define TPS6586X_INT_ACK2	0xb6
#define TPS6586X_INT_ACK3	0xb7
#define TPS6586X_INT_ACK4	0xb8

/* interrupt mask registers */
#define TPS6586X_INT_MASK1	0xb0
#define TPS6586X_INT_MASK2	0xb1
#define TPS6586X_INT_MASK3	0xb2
#define TPS6586X_INT_MASK4	0xb3
#define TPS6586X_INT_MASK5	0xb4

/* device id */
#define TPS6586X_VERSIONCRC	0xcd

/* Maximum register */
#define TPS6586X_MAX_REGISTER	(TPS6586X_VERSIONCRC + 1)

struct tps6586x_irq_data {
	u8	mask_reg;
	u8	mask_mask;
};

#define TPS6586X_IRQ(_reg, _mask)				\
	{							\
		.mask_reg = (_reg) - TPS6586X_INT_MASK1,	\
		.mask_mask = (_mask),				\
	}

static const struct tps6586x_irq_data tps6586x_irqs[] = {
	[TPS6586X_INT_PLDO_0]	= TPS6586X_IRQ(TPS6586X_INT_MASK1, 1 << 0),
	[TPS6586X_INT_PLDO_1]	= TPS6586X_IRQ(TPS6586X_INT_MASK1, 1 << 1),
	[TPS6586X_INT_PLDO_2]	= TPS6586X_IRQ(TPS6586X_INT_MASK1, 1 << 2),
	[TPS6586X_INT_PLDO_3]	= TPS6586X_IRQ(TPS6586X_INT_MASK1, 1 << 3),
	[TPS6586X_INT_PLDO_4]	= TPS6586X_IRQ(TPS6586X_INT_MASK1, 1 << 4),
	[TPS6586X_INT_PLDO_5]	= TPS6586X_IRQ(TPS6586X_INT_MASK1, 1 << 5),
	[TPS6586X_INT_PLDO_6]	= TPS6586X_IRQ(TPS6586X_INT_MASK1, 1 << 6),
	[TPS6586X_INT_PLDO_7]	= TPS6586X_IRQ(TPS6586X_INT_MASK1, 1 << 7),
	[TPS6586X_INT_COMP_DET]	= TPS6586X_IRQ(TPS6586X_INT_MASK4, 1 << 0),
	[TPS6586X_INT_ADC]	= TPS6586X_IRQ(TPS6586X_INT_MASK2, 1 << 1),
	[TPS6586X_INT_PLDO_8]	= TPS6586X_IRQ(TPS6586X_INT_MASK2, 1 << 2),
	[TPS6586X_INT_PLDO_9]	= TPS6586X_IRQ(TPS6586X_INT_MASK2, 1 << 3),
	[TPS6586X_INT_PSM_0]	= TPS6586X_IRQ(TPS6586X_INT_MASK2, 1 << 4),
	[TPS6586X_INT_PSM_1]	= TPS6586X_IRQ(TPS6586X_INT_MASK2, 1 << 5),
	[TPS6586X_INT_PSM_2]	= TPS6586X_IRQ(TPS6586X_INT_MASK2, 1 << 6),
	[TPS6586X_INT_PSM_3]	= TPS6586X_IRQ(TPS6586X_INT_MASK2, 1 << 7),
	[TPS6586X_INT_RTC_ALM1]	= TPS6586X_IRQ(TPS6586X_INT_MASK5, 1 << 4),
	[TPS6586X_INT_ACUSB_OVP] = TPS6586X_IRQ(TPS6586X_INT_MASK5, 0x03),
	[TPS6586X_INT_USB_DET]	= TPS6586X_IRQ(TPS6586X_INT_MASK5, 1 << 2),
	[TPS6586X_INT_AC_DET]	= TPS6586X_IRQ(TPS6586X_INT_MASK5, 1 << 3),
	[TPS6586X_INT_BAT_DET]	= TPS6586X_IRQ(TPS6586X_INT_MASK3, 1 << 0),
	[TPS6586X_INT_CHG_STAT]	= TPS6586X_IRQ(TPS6586X_INT_MASK4, 0xfc),
	[TPS6586X_INT_CHG_TEMP]	= TPS6586X_IRQ(TPS6586X_INT_MASK3, 0x06),
	[TPS6586X_INT_PP]	= TPS6586X_IRQ(TPS6586X_INT_MASK3, 0xf0),
	[TPS6586X_INT_RESUME]	= TPS6586X_IRQ(TPS6586X_INT_MASK5, 1 << 5),
	[TPS6586X_INT_LOW_SYS]	= TPS6586X_IRQ(TPS6586X_INT_MASK5, 1 << 6),
	[TPS6586X_INT_RTC_ALM2] = TPS6586X_IRQ(TPS6586X_INT_MASK4, 1 << 1),
};

static struct resource tps6586x_rtc_resources[] = {
	{
		.start  = TPS6586X_INT_RTC_ALM1,
		.end	= TPS6586X_INT_RTC_ALM1,
		.flags	= IORESOURCE_IRQ,
	},
};

static struct mfd_cell tps6586x_cell[] = {
	{
		.name = "tps6586x-gpio",
	},
	{
		.name = "tps6586x-regulator",
	},
	{
		.name = "tps6586x-rtc",
		.num_resources = ARRAY_SIZE(tps6586x_rtc_resources),
		.resources = &tps6586x_rtc_resources[0],
	},
	{
		.name = "tps6586x-onkey",
	},
};

struct tps6586x {
	struct device		*dev;
	struct i2c_client	*client;
	struct regmap		*regmap;

	struct irq_chip		irq_chip;
	struct mutex		irq_lock;
	int			irq_base;
	u32			irq_en;
	u8			mask_reg[5];
	struct irq_domain	*irq_domain;
};

static inline struct tps6586x *dev_to_tps6586x(struct device *dev)
{
	return i2c_get_clientdata(to_i2c_client(dev));
}

int tps6586x_write(struct device *dev, int reg, uint8_t val)
{
	struct tps6586x *tps6586x = dev_to_tps6586x(dev);

	return regmap_write(tps6586x->regmap, reg, val);
}
EXPORT_SYMBOL_GPL(tps6586x_write);

int tps6586x_writes(struct device *dev, int reg, int len, uint8_t *val)
{
	struct tps6586x *tps6586x = dev_to_tps6586x(dev);

	return regmap_bulk_write(tps6586x->regmap, reg, val, len);
}
EXPORT_SYMBOL_GPL(tps6586x_writes);

int tps6586x_read(struct device *dev, int reg, uint8_t *val)
{
	struct tps6586x *tps6586x = dev_to_tps6586x(dev);
	unsigned int rval;
	int ret;

	ret = regmap_read(tps6586x->regmap, reg, &rval);
	if (!ret)
		*val = rval;
	return ret;
}
EXPORT_SYMBOL_GPL(tps6586x_read);

int tps6586x_reads(struct device *dev, int reg, int len, uint8_t *val)
{
	struct tps6586x *tps6586x = dev_to_tps6586x(dev);

	return regmap_bulk_read(tps6586x->regmap, reg, val, len);
}
EXPORT_SYMBOL_GPL(tps6586x_reads);

int tps6586x_set_bits(struct device *dev, int reg, uint8_t bit_mask)
{
	struct tps6586x *tps6586x = dev_to_tps6586x(dev);

	return regmap_update_bits(tps6586x->regmap, reg, bit_mask, bit_mask);
}
EXPORT_SYMBOL_GPL(tps6586x_set_bits);

int tps6586x_clr_bits(struct device *dev, int reg, uint8_t bit_mask)
{
	struct tps6586x *tps6586x = dev_to_tps6586x(dev);

	return regmap_update_bits(tps6586x->regmap, reg, bit_mask, 0);
}
EXPORT_SYMBOL_GPL(tps6586x_clr_bits);

int tps6586x_update(struct device *dev, int reg, uint8_t val, uint8_t mask)
{
	struct tps6586x *tps6586x = dev_to_tps6586x(dev);

	return regmap_update_bits(tps6586x->regmap, reg, mask, val);
}
EXPORT_SYMBOL_GPL(tps6586x_update);

int tps6586x_irq_get_virq(struct device *dev, int irq)
{
	struct tps6586x *tps6586x = dev_to_tps6586x(dev);

	return irq_create_mapping(tps6586x->irq_domain, irq);
}
EXPORT_SYMBOL_GPL(tps6586x_irq_get_virq);

static int __remove_subdev(struct device *dev, void *unused)
{
	platform_device_unregister(to_platform_device(dev));
	return 0;
}

static int tps6586x_remove_subdevs(struct tps6586x *tps6586x)
{
	return device_for_each_child(tps6586x->dev, NULL, __remove_subdev);
}

static void tps6586x_irq_lock(struct irq_data *data)
{
	struct tps6586x *tps6586x = irq_data_get_irq_chip_data(data);

	mutex_lock(&tps6586x->irq_lock);
}

static void tps6586x_irq_enable(struct irq_data *irq_data)
{
	struct tps6586x *tps6586x = irq_data_get_irq_chip_data(irq_data);
	unsigned int __irq = irq_data->hwirq;
	const struct tps6586x_irq_data *data = &tps6586x_irqs[__irq];

	tps6586x->mask_reg[data->mask_reg] &= ~data->mask_mask;
	tps6586x->irq_en |= (1 << __irq);
}

static void tps6586x_irq_disable(struct irq_data *irq_data)
{
	struct tps6586x *tps6586x = irq_data_get_irq_chip_data(irq_data);

	unsigned int __irq = irq_data->hwirq;
	const struct tps6586x_irq_data *data = &tps6586x_irqs[__irq];

	tps6586x->mask_reg[data->mask_reg] |= data->mask_mask;
	tps6586x->irq_en &= ~(1 << __irq);
}

static void tps6586x_irq_sync_unlock(struct irq_data *data)
{
	struct tps6586x *tps6586x = irq_data_get_irq_chip_data(data);
	int i;

	for (i = 0; i < ARRAY_SIZE(tps6586x->mask_reg); i++) {
		int ret;
		ret = tps6586x_write(tps6586x->dev,
					    TPS6586X_INT_MASK1 + i,
					    tps6586x->mask_reg[i]);
		WARN_ON(ret);
	}

	mutex_unlock(&tps6586x->irq_lock);
}

static struct irq_chip tps6586x_irq_chip = {
	.name = "tps6586x",
	.irq_bus_lock = tps6586x_irq_lock,
	.irq_bus_sync_unlock = tps6586x_irq_sync_unlock,
	.irq_disable = tps6586x_irq_disable,
	.irq_enable = tps6586x_irq_enable,
};

static int tps6586x_irq_map(struct irq_domain *h, unsigned int virq,
				irq_hw_number_t hw)
{
	struct tps6586x *tps6586x = h->host_data;

	irq_set_chip_data(virq, tps6586x);
	irq_set_chip_and_handler(virq, &tps6586x_irq_chip, handle_simple_irq);
	irq_set_nested_thread(virq, 1);

	/* ARM needs us to explicitly flag the IRQ as valid
	 * and will set them noprobe when we do so. */
#ifdef CONFIG_ARM
	set_irq_flags(virq, IRQF_VALID);
#else
	irq_set_noprobe(virq);
#endif

	return 0;
}

static struct irq_domain_ops tps6586x_domain_ops = {
	.map    = tps6586x_irq_map,
	.xlate  = irq_domain_xlate_twocell,
};

static irqreturn_t tps6586x_irq(int irq, void *data)
{
	struct tps6586x *tps6586x = data;
	u32 acks;
	int ret = 0;

	ret = tps6586x_reads(tps6586x->dev, TPS6586X_INT_ACK1,
			     sizeof(acks), (uint8_t *)&acks);

	if (ret < 0) {
		dev_err(tps6586x->dev, "failed to read interrupt status\n");
		return IRQ_NONE;
	}

	acks = le32_to_cpu(acks);

	while (acks) {
		int i = __ffs(acks);

		if (tps6586x->irq_en & (1 << i))
			handle_nested_irq(
				irq_find_mapping(tps6586x->irq_domain, i));

		acks &= ~(1 << i);
	}

	return IRQ_HANDLED;
}

static int tps6586x_irq_init(struct tps6586x *tps6586x, int irq,
				       int irq_base)
{
	int i, ret;
	u8 tmp[4];
	int new_irq_base;
	int irq_num = ARRAY_SIZE(tps6586x_irqs);

	mutex_init(&tps6586x->irq_lock);
	for (i = 0; i < 5; i++) {
		tps6586x->mask_reg[i] = 0xff;
		tps6586x_write(tps6586x->dev, TPS6586X_INT_MASK1 + i, 0xff);
	}

	tps6586x_reads(tps6586x->dev, TPS6586X_INT_ACK1, sizeof(tmp), tmp);

	if  (irq_base > 0) {
		new_irq_base = irq_alloc_descs(irq_base, 0, irq_num, -1);
		if (new_irq_base < 0) {
			dev_err(tps6586x->dev,
				"Failed to alloc IRQs: %d\n", new_irq_base);
			return new_irq_base;
		}
	} else {
		new_irq_base = 0;
	}

	tps6586x->irq_domain = irq_domain_add_simple(tps6586x->dev->of_node,
				irq_num, new_irq_base, &tps6586x_domain_ops,
				tps6586x);
	if (!tps6586x->irq_domain) {
		dev_err(tps6586x->dev, "Failed to create IRQ domain\n");
		return -ENOMEM;
	}
	ret = request_threaded_irq(irq, NULL, tps6586x_irq, IRQF_ONESHOT,
				   "tps6586x", tps6586x);

	if (!ret) {
		device_init_wakeup(tps6586x->dev, 1);
		enable_irq_wake(irq);
	}

	return ret;
}

static int tps6586x_add_subdevs(struct tps6586x *tps6586x,
					  struct tps6586x_platform_data *pdata)
{
	struct tps6586x_subdev_info *subdev;
	struct platform_device *pdev;
	int i, ret = 0;

	for (i = 0; i < pdata->num_subdevs; i++) {
		subdev = &pdata->subdevs[i];

		pdev = platform_device_alloc(subdev->name, subdev->id);
		if (!pdev) {
			ret = -ENOMEM;
			goto failed;
		}

		pdev->dev.parent = tps6586x->dev;
		pdev->dev.platform_data = subdev->platform_data;
		pdev->dev.of_node = subdev->of_node;

		ret = platform_device_add(pdev);
		if (ret) {
			platform_device_put(pdev);
			goto failed;
		}
	}
	return 0;

failed:
	tps6586x_remove_subdevs(tps6586x);
	return ret;
}

#ifdef CONFIG_OF
static struct tps6586x_platform_data *tps6586x_parse_dt(struct i2c_client *client)
{
	struct device_node *np = client->dev.of_node;
	struct tps6586x_platform_data *pdata;

	pdata = devm_kzalloc(&client->dev, sizeof(*pdata), GFP_KERNEL);
	if (!pdata) {
		dev_err(&client->dev, "Memory allocation failed\n");
		return NULL;
	}

	pdata->num_subdevs = 0;
	pdata->subdevs = NULL;
	pdata->gpio_base = -1;
	pdata->irq_base = -1;
	pdata->pm_off = of_property_read_bool(np, "ti,system-power-controller");

	return pdata;
}

static struct of_device_id tps6586x_of_match[] = {
	{ .compatible = "ti,tps6586x", },
	{ },
};
#else
static struct tps6586x_platform_data *tps6586x_parse_dt(struct i2c_client *client)
{
	return NULL;
}
#endif

static bool is_volatile_reg(struct device *dev, unsigned int reg)
{
	/* Cache all interrupt mask register */
	if ((reg >= TPS6586X_INT_MASK1) && (reg <= TPS6586X_INT_MASK5))
		return false;

	return true;
}

static const struct regmap_config tps6586x_regmap_config = {
	.reg_bits = 8,
	.val_bits = 8,
	.max_register = TPS6586X_MAX_REGISTER - 1,
	.volatile_reg = is_volatile_reg,
	.cache_type = REGCACHE_RBTREE,
};

static struct device *tps6586x_dev;
static void tps6586x_power_off(void)
{
	if (tps6586x_clr_bits(tps6586x_dev, TPS6586X_SUPPLYENE, EXITSLREQ_BIT))
		return;

	tps6586x_set_bits(tps6586x_dev, TPS6586X_SUPPLYENE, SLEEP_MODE_BIT);
}

static int tps6586x_i2c_probe(struct i2c_client *client,
					const struct i2c_device_id *id)
{
	struct tps6586x_platform_data *pdata = client->dev.platform_data;
	struct tps6586x *tps6586x;
	int ret;

	if (!pdata && client->dev.of_node)
		pdata = tps6586x_parse_dt(client);

	if (!pdata) {
		dev_err(&client->dev, "tps6586x requires platform data\n");
		return -ENOTSUPP;
	}

	ret = i2c_smbus_read_byte_data(client, TPS6586X_VERSIONCRC);
	if (ret < 0) {
		dev_err(&client->dev, "Chip ID read failed: %d\n", ret);
		return -EIO;
	}

	dev_info(&client->dev, "VERSIONCRC is %02x\n", ret);

	tps6586x = devm_kzalloc(&client->dev, sizeof(*tps6586x), GFP_KERNEL);
	if (tps6586x == NULL) {
		dev_err(&client->dev, "memory for tps6586x alloc failed\n");
		return -ENOMEM;
	}

	tps6586x->client = client;
	tps6586x->dev = &client->dev;
	i2c_set_clientdata(client, tps6586x);

	tps6586x->regmap = devm_regmap_init_i2c(client,
					&tps6586x_regmap_config);
	if (IS_ERR(tps6586x->regmap)) {
		ret = PTR_ERR(tps6586x->regmap);
		dev_err(&client->dev, "regmap init failed: %d\n", ret);
		return ret;
	}


	if (client->irq) {
		ret = tps6586x_irq_init(tps6586x, client->irq,
					pdata->irq_base);
		if (ret) {
			dev_err(&client->dev, "IRQ init failed: %d\n", ret);
			return ret;
		}
	}

	ret = mfd_add_devices(tps6586x->dev, -1,
			      tps6586x_cell, ARRAY_SIZE(tps6586x_cell),
			      NULL, 0, tps6586x->irq_domain);
	if (ret < 0) {
		dev_err(&client->dev, "mfd_add_devices failed: %d\n", ret);
		goto err_mfd_add;
	}

	ret = tps6586x_add_subdevs(tps6586x, pdata);
	if (ret) {
		dev_err(&client->dev, "add devices failed: %d\n", ret);
		goto err_add_devs;
	}

	if (pdata->pm_off && !pm_power_off) {
		tps6586x_dev = &client->dev;
		pm_power_off = tps6586x_power_off;
	}

	return 0;

err_add_devs:
	mfd_remove_devices(tps6586x->dev);
err_mfd_add:
	if (client->irq)
		free_irq(client->irq, tps6586x);
	return ret;
}

static int tps6586x_i2c_remove(struct i2c_client *client)
{
	struct tps6586x *tps6586x = i2c_get_clientdata(client);

	tps6586x_remove_subdevs(tps6586x);
	mfd_remove_devices(tps6586x->dev);
	if (client->irq)
		free_irq(client->irq, tps6586x);
	return 0;
}

static const struct i2c_device_id tps6586x_id_table[] = {
	{ "tps6586x", 0 },
	{ },
};
MODULE_DEVICE_TABLE(i2c, tps6586x_id_table);

static struct i2c_driver tps6586x_driver = {
	.driver	= {
		.name	= "tps6586x",
		.owner	= THIS_MODULE,
		.of_match_table = of_match_ptr(tps6586x_of_match),
	},
	.probe		= tps6586x_i2c_probe,
	.remove		= tps6586x_i2c_remove,
	.id_table	= tps6586x_id_table,
};

static int __init tps6586x_init(void)
{
	return i2c_add_driver(&tps6586x_driver);
}
subsys_initcall(tps6586x_init);

static void __exit tps6586x_exit(void)
{
	i2c_del_driver(&tps6586x_driver);
}
module_exit(tps6586x_exit);

MODULE_DESCRIPTION("TPS6586X core driver");
MODULE_AUTHOR("Mike Rapoport <mike@compulab.co.il>");
MODULE_LICENSE("GPL");