/*
 * Copyright (C) ST-Ericsson SA 2011
 *
 * License Terms: GNU General Public License v2
 * Authors: Sundar Iyer <sundar.iyer@stericsson.com> for ST-Ericsson
 *          Bengt Jonsson <bengt.g.jonsson@stericsson.com> for ST-Ericsson
 *
 * Power domain regulators on DB5500
 */

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/err.h>
#include <linux/spinlock.h>
#include <linux/platform_device.h>
#include <linux/regulator/driver.h>
#include <linux/regulator/machine.h>
#include <linux/regulator/db5500-prcmu.h>

#include <linux/mfd/dbx500-prcmu.h>

#include "dbx500-prcmu.h"
static int db5500_regulator_enable(struct regulator_dev *rdev)
{
	struct dbx500_regulator_info *info = rdev_get_drvdata(rdev);

	if (info == NULL)
		return -EINVAL;

	dev_vdbg(rdev_get_dev(rdev), "regulator-%s-enable\n",
		info->desc.name);

	info->is_enabled = true;
	if (!info->exclude_from_power_state)
		power_state_active_enable();

	return 0;
}

static int db5500_regulator_disable(struct regulator_dev *rdev)
{
	struct dbx500_regulator_info *info = rdev_get_drvdata(rdev);
	int ret = 0;

	if (info == NULL)
		return -EINVAL;

	dev_vdbg(rdev_get_dev(rdev), "regulator-%s-disable\n",
		info->desc.name);

	info->is_enabled = false;
	if (!info->exclude_from_power_state)
		ret = power_state_active_disable();

	return ret;
}

static int db5500_regulator_is_enabled(struct regulator_dev *rdev)
{
	struct dbx500_regulator_info *info = rdev_get_drvdata(rdev);

	if (info == NULL)
		return -EINVAL;

	dev_vdbg(rdev_get_dev(rdev), "regulator-%s-is_enabled (is_enabled):"
		" %i\n", info->desc.name, info->is_enabled);

	return info->is_enabled;
}

/* db5500 regulator operations */
static struct regulator_ops db5500_regulator_ops = {
	.enable			= db5500_regulator_enable,
	.disable		= db5500_regulator_disable,
	.is_enabled		= db5500_regulator_is_enabled,
};

/*
 * EPOD control
 */
static bool epod_on[NUM_EPOD_ID];
static bool epod_ramret[NUM_EPOD_ID];

static inline int epod_id_to_index(u16 epod_id)
{
	return epod_id - DB5500_EPOD_ID_BASE;
}

static int enable_epod(u16 epod_id, bool ramret)
{
	int idx = epod_id_to_index(epod_id);
	int ret;

	if (ramret) {
		if (!epod_on[idx]) {
			ret = prcmu_set_epod(epod_id, EPOD_STATE_RAMRET);
			if (ret < 0)
				return ret;
		}
		epod_ramret[idx] = true;
	} else {
		ret = prcmu_set_epod(epod_id, EPOD_STATE_ON);
		if (ret < 0)
			return ret;
		epod_on[idx] = true;
	}

	return 0;
}

static int disable_epod(u16 epod_id, bool ramret)
{
	int idx = epod_id_to_index(epod_id);
	int ret;

	if (ramret) {
		if (!epod_on[idx]) {
			ret = prcmu_set_epod(epod_id, EPOD_STATE_OFF);
			if (ret < 0)
				return ret;
		}
		epod_ramret[idx] = false;
	} else {
		if (epod_ramret[idx]) {
			ret = prcmu_set_epod(epod_id, EPOD_STATE_RAMRET);
			if (ret < 0)
				return ret;
		} else {
			ret = prcmu_set_epod(epod_id, EPOD_STATE_OFF);
			if (ret < 0)
				return ret;
		}
		epod_on[idx] = false;
	}

	return 0;
}

/*
 * Regulator switch
 */
static int db5500_regulator_switch_enable(struct regulator_dev *rdev)
{
	struct dbx500_regulator_info *info = rdev_get_drvdata(rdev);
	int ret;

	if (info == NULL)
		return -EINVAL;

	dev_vdbg(rdev_get_dev(rdev), "regulator-switch-%s-enable\n",
		info->desc.name);

	ret = enable_epod(info->epod_id, info->is_ramret);
	if (ret < 0) {
		dev_err(rdev_get_dev(rdev),
			"regulator-switch-%s-enable: prcmu call failed\n",
			info->desc.name);
		goto out;
	}

	info->is_enabled = true;
out:
	return ret;
}

static int db5500_regulator_switch_disable(struct regulator_dev *rdev)
{
	struct dbx500_regulator_info *info = rdev_get_drvdata(rdev);
	int ret;

	if (info == NULL)
		return -EINVAL;

	dev_vdbg(rdev_get_dev(rdev), "regulator-switch-%s-disable\n",
		info->desc.name);

	ret = disable_epod(info->epod_id, info->is_ramret);
	if (ret < 0) {
		dev_err(rdev_get_dev(rdev),
			"regulator_switch-%s-disable: prcmu call failed\n",
			info->desc.name);
		goto out;
	}

	info->is_enabled = 0;
out:
	return ret;
}

static int db5500_regulator_switch_is_enabled(struct regulator_dev *rdev)
{
	struct dbx500_regulator_info *info = rdev_get_drvdata(rdev);

	if (info == NULL)
		return -EINVAL;

	dev_vdbg(rdev_get_dev(rdev),
		"regulator-switch-%s-is_enabled (is_enabled): %i\n",
		info->desc.name, info->is_enabled);

	return info->is_enabled;
}

static struct regulator_ops db5500_regulator_switch_ops = {
	.enable			= db5500_regulator_switch_enable,
	.disable		= db5500_regulator_switch_disable,
	.is_enabled		= db5500_regulator_switch_is_enabled,
};

/*
 * Regulator information
 */
#define DB5500_REGULATOR_SWITCH(_name, reg)                               \
	[DB5500_REGULATOR_SWITCH_##reg] = {                               \
		.desc = {                                               \
			.name   = _name,                                \
			.id     = DB5500_REGULATOR_SWITCH_##reg,          \
			.ops    = &db5500_regulator_switch_ops,          \
			.type   = REGULATOR_VOLTAGE,                    \
			.owner  = THIS_MODULE,                          \
		},                                                      \
		.epod_id = DB5500_EPOD_ID_##reg,                         \
}

static struct dbx500_regulator_info
		dbx500_regulator_info[DB5500_NUM_REGULATORS] = {
	[DB5500_REGULATOR_VAPE] = {
		.desc = {
			.name	= "db5500-vape",
			.id	= DB5500_REGULATOR_VAPE,
			.ops	= &db5500_regulator_ops,
			.type	= REGULATOR_VOLTAGE,
			.owner	= THIS_MODULE,
		},
	},
	DB5500_REGULATOR_SWITCH("db5500-sga", SGA),
	DB5500_REGULATOR_SWITCH("db5500-hva", HVA),
	DB5500_REGULATOR_SWITCH("db5500-sia", SIA),
	DB5500_REGULATOR_SWITCH("db5500-disp", DISP),
	DB5500_REGULATOR_SWITCH("db5500-esram12", ESRAM12),
};

static int __devinit db5500_regulator_probe(struct platform_device *pdev)
{
	struct regulator_init_data *db5500_init_data =
					dev_get_platdata(&pdev->dev);
	int i, err;

	/* register all regulators */
	for (i = 0; i < ARRAY_SIZE(dbx500_regulator_info); i++) {
		struct dbx500_regulator_info *info;
		struct regulator_init_data *init_data = &db5500_init_data[i];

		/* assign per-regulator data */
		info = &dbx500_regulator_info[i];
		info->dev = &pdev->dev;

		/* register with the regulator framework */
		info->rdev = regulator_register(&info->desc, &pdev->dev,
				init_data, info);
		if (IS_ERR(info->rdev)) {
			err = PTR_ERR(info->rdev);
			dev_err(&pdev->dev, "failed to register %s: err %i\n",
				info->desc.name, err);

			/* if failing, unregister all earlier regulators */
			i--;
			while (i >= 0) {
				info = &dbx500_regulator_info[i];
				regulator_unregister(info->rdev);
				i--;
			}
			return err;
		}

		dev_dbg(rdev_get_dev(info->rdev),
			"regulator-%s-probed\n", info->desc.name);
	}

	return 0;
}

static int __exit db5500_regulator_remove(struct platform_device *pdev)
{
	int i;

	for (i = 0; i < ARRAY_SIZE(dbx500_regulator_info); i++) {
		struct dbx500_regulator_info *info;
		info = &dbx500_regulator_info[i];

		dev_vdbg(rdev_get_dev(info->rdev),
			"regulator-%s-remove\n", info->desc.name);

		regulator_unregister(info->rdev);
	}

	return 0;
}

static struct platform_driver db5500_regulator_driver = {
	.driver = {
		.name = "db5500-prcmu-regulators",
		.owner = THIS_MODULE,
	},
	.probe = db5500_regulator_probe,
	.remove = __exit_p(db5500_regulator_remove),
};

static int __init db5500_regulator_init(void)
{
	int ret;

	ret = platform_driver_register(&db5500_regulator_driver);
	if (ret < 0)
		return -ENODEV;

	return 0;
}

static void __exit db5500_regulator_exit(void)
{
	platform_driver_unregister(&db5500_regulator_driver);
}

arch_initcall(db5500_regulator_init);
module_exit(db5500_regulator_exit);

MODULE_AUTHOR("STMicroelectronics/ST-Ericsson");
MODULE_DESCRIPTION("DB5500 regulator driver");
MODULE_LICENSE("GPL v2");