/*
 * arizona-micsupp.c  --  Microphone supply for Arizona devices
 *
 * Copyright 2012 Wolfson Microelectronics PLC.
 *
 * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
 *
 *  This program is free software; you can redistribute  it and/or modify it
 *  under  the terms of  the GNU General  Public License as published by the
 *  Free Software Foundation;  either version 2 of the  License, or (at your
 *  option) any later version.
 */

#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/init.h>
#include <linux/bitops.h>
#include <linux/err.h>
#include <linux/platform_device.h>
#include <linux/regulator/driver.h>
#include <linux/regulator/machine.h>
#include <linux/gpio.h>
#include <linux/slab.h>
#include <linux/workqueue.h>
#include <sound/soc.h>

#include <linux/mfd/arizona/core.h>
#include <linux/mfd/arizona/pdata.h>
#include <linux/mfd/arizona/registers.h>

#define ARIZONA_MICSUPP_MAX_SELECTOR 0x1f

struct arizona_micsupp {
        struct regulator_dev *regulator;
        struct arizona *arizona;

        struct regulator_consumer_supply supply;
        struct regulator_init_data init_data;

        struct work_struct check_cp_work;
};

static int arizona_micsupp_list_voltage(struct regulator_dev *rdev,
                                        unsigned int selector)
{
        if (selector > ARIZONA_MICSUPP_MAX_SELECTOR)
                return -EINVAL;

        if (selector == ARIZONA_MICSUPP_MAX_SELECTOR)
                return 3300000;
        else
                return (selector * 50000) + 1700000;
}

static int arizona_micsupp_map_voltage(struct regulator_dev *rdev,
                                       int min_uV, int max_uV)
{
        unsigned int voltage;
        int selector;

        if (min_uV < 1700000)
                min_uV = 1700000;

        if (min_uV > 3200000)
                selector = ARIZONA_MICSUPP_MAX_SELECTOR;
        else
                selector = DIV_ROUND_UP(min_uV - 1700000, 50000);

        if (selector < 0)
                return -EINVAL;

        voltage = arizona_micsupp_list_voltage(rdev, selector);
        if (voltage < min_uV || voltage > max_uV)
                return -EINVAL;

        return selector;
}

static void arizona_micsupp_check_cp(struct work_struct *work)
{
        struct arizona_micsupp *micsupp =
                container_of(work, struct arizona_micsupp, check_cp_work);
        struct snd_soc_dapm_context *dapm = micsupp->arizona->dapm;
        struct arizona *arizona = micsupp->arizona;
        struct regmap *regmap = arizona->regmap;
        unsigned int reg;
        int ret;

        ret = regmap_read(regmap, ARIZONA_MIC_CHARGE_PUMP_1, &reg);
        if (ret != 0) {
                dev_err(arizona->dev, "Failed to read CP state: %d\n", ret);
                return;
        }

        if (dapm) {
                if ((reg & (ARIZONA_CPMIC_ENA | ARIZONA_CPMIC_BYPASS)) ==
                    ARIZONA_CPMIC_ENA)
                        snd_soc_dapm_force_enable_pin(dapm, "MICSUPP");
                else
                        snd_soc_dapm_disable_pin(dapm, "MICSUPP");

                snd_soc_dapm_sync(dapm);
        }
}

static int arizona_micsupp_enable(struct regulator_dev *rdev)
{
        struct arizona_micsupp *micsupp = rdev_get_drvdata(rdev);
        int ret;

        ret = regulator_enable_regmap(rdev);

        if (ret == 0)
                schedule_work(&micsupp->check_cp_work);

        return ret;
}

static int arizona_micsupp_disable(struct regulator_dev *rdev)
{
        struct arizona_micsupp *micsupp = rdev_get_drvdata(rdev);
        int ret;

        ret = regulator_disable_regmap(rdev);
        if (ret == 0)
                schedule_work(&micsupp->check_cp_work);

        return ret;
}

static int arizona_micsupp_set_bypass(struct regulator_dev *rdev, bool ena)
{
        struct arizona_micsupp *micsupp = rdev_get_drvdata(rdev);
        int ret;

        ret = regulator_set_bypass_regmap(rdev, ena);
        if (ret == 0)
                schedule_work(&micsupp->check_cp_work);

        return ret;
}

static struct regulator_ops arizona_micsupp_ops = {
        .enable = arizona_micsupp_enable,
        .disable = arizona_micsupp_disable,
        .is_enabled = regulator_is_enabled_regmap,

        .list_voltage = arizona_micsupp_list_voltage,
        .map_voltage = arizona_micsupp_map_voltage,

        .get_voltage_sel = regulator_get_voltage_sel_regmap,
        .set_voltage_sel = regulator_set_voltage_sel_regmap,

        .get_bypass = regulator_get_bypass_regmap,
        .set_bypass = arizona_micsupp_set_bypass,
};

static const struct regulator_desc arizona_micsupp = {
        .name = "MICVDD",
        .supply_name = "CPVDD",
        .type = REGULATOR_VOLTAGE,
        .n_voltages = ARIZONA_MICSUPP_MAX_SELECTOR + 1,
        .ops = &arizona_micsupp_ops,

        .vsel_reg = ARIZONA_LDO2_CONTROL_1,
        .vsel_mask = ARIZONA_LDO2_VSEL_MASK,
        .enable_reg = ARIZONA_MIC_CHARGE_PUMP_1,
        .enable_mask = ARIZONA_CPMIC_ENA,
        .bypass_reg = ARIZONA_MIC_CHARGE_PUMP_1,
        .bypass_mask = ARIZONA_CPMIC_BYPASS,

        .enable_time = 3000,

        .owner = THIS_MODULE,
};

static const struct regulator_init_data arizona_micsupp_default = {
        .constraints = {
                .valid_ops_mask = REGULATOR_CHANGE_STATUS |
                                REGULATOR_CHANGE_VOLTAGE |
                                REGULATOR_CHANGE_BYPASS,
                .min_uV = 1700000,
                .max_uV = 3300000,
        },

        .num_consumer_supplies = 1,
};

static int arizona_micsupp_probe(struct platform_device *pdev)
{
        struct arizona *arizona = dev_get_drvdata(pdev->dev.parent);
        struct regulator_config config = { };
        struct arizona_micsupp *micsupp;
        int ret;

        micsupp = devm_kzalloc(&pdev->dev, sizeof(*micsupp), GFP_KERNEL);
        if (micsupp == NULL) {
                dev_err(&pdev->dev, "Unable to allocate private data\n");
                return -ENOMEM;
        }

        micsupp->arizona = arizona;
        INIT_WORK(&micsupp->check_cp_work, arizona_micsupp_check_cp);

        /*
         * Since the chip usually supplies itself we provide some
         * default init_data for it.  This will be overridden with
         * platform data if provided.
         */
        micsupp->init_data = arizona_micsupp_default;
        micsupp->init_data.consumer_supplies = &micsupp->supply;
        micsupp->supply.supply = "MICVDD";
        micsupp->supply.dev_name = dev_name(arizona->dev);

        config.dev = arizona->dev;
        config.driver_data = micsupp;
        config.regmap = arizona->regmap;

        if (arizona->pdata.micvdd)
                config.init_data = arizona->pdata.micvdd;
        else
                config.init_data = &micsupp->init_data;

        /* Default to regulated mode until the API supports bypass */
        regmap_update_bits(arizona->regmap, ARIZONA_MIC_CHARGE_PUMP_1,
                           ARIZONA_CPMIC_BYPASS, 0);

        micsupp->regulator = regulator_register(&arizona_micsupp, &config);
        if (IS_ERR(micsupp->regulator)) {
                ret = PTR_ERR(micsupp->regulator);
                dev_err(arizona->dev, "Failed to register mic supply: %d\n",
                        ret);
                return ret;
        }

        platform_set_drvdata(pdev, micsupp);

        return 0;
}

static int arizona_micsupp_remove(struct platform_device *pdev)
{
        struct arizona_micsupp *micsupp = platform_get_drvdata(pdev);

        regulator_unregister(micsupp->regulator);

        return 0;
}

static struct platform_driver arizona_micsupp_driver = {
        .probe = arizona_micsupp_probe,
        .remove = arizona_micsupp_remove,
        .driver         = {
                .name   = "arizona-micsupp",
                .owner  = THIS_MODULE,
        },
};

module_platform_driver(arizona_micsupp_driver);

/* Module information */
MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
MODULE_DESCRIPTION("Arizona microphone supply driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:arizona-micsupp");