// SPDX-License-Identifier: GPL-2.0-only
/* Copyright (c) 2010-2011, Code Aurora Forum. All rights reserved.
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/slab.h>
#include <linux/input.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/log2.h>
#include <linux/of.h>

#define PON_CNTL_1 0x1C
#define PON_CNTL_PULL_UP BIT(7)
#define PON_CNTL_TRIG_DELAY_MASK (0x7)
#define PON_CNTL_1_PULL_UP_EN                   0xe0
#define PON_CNTL_1_USB_PWR_EN                   0x10
#define PON_CNTL_1_WD_EN_RESET                  0x08

#define PM8058_SLEEP_CTRL                       0x02b
#define PM8921_SLEEP_CTRL                       0x10a

#define SLEEP_CTRL_SMPL_EN_RESET                0x04

/* Regulator master enable addresses */
#define REG_PM8058_VREG_EN_MSM                  0x018
#define REG_PM8058_VREG_EN_GRP_5_4              0x1c8

/* Regulator control registers for shutdown/reset */
#define PM8058_S0_CTRL                          0x004
#define PM8058_S1_CTRL                          0x005
#define PM8058_S3_CTRL                          0x111
#define PM8058_L21_CTRL                         0x120
#define PM8058_L22_CTRL                         0x121

#define PM8058_REGULATOR_ENABLE_MASK            0x80
#define PM8058_REGULATOR_ENABLE                 0x80
#define PM8058_REGULATOR_DISABLE                0x00
#define PM8058_REGULATOR_PULL_DOWN_MASK         0x40
#define PM8058_REGULATOR_PULL_DOWN_EN           0x40

/* Buck CTRL register */
#define PM8058_SMPS_LEGACY_VREF_SEL             0x20
#define PM8058_SMPS_LEGACY_VPROG_MASK           0x1f
#define PM8058_SMPS_ADVANCED_BAND_MASK          0xC0
#define PM8058_SMPS_ADVANCED_BAND_SHIFT         6
#define PM8058_SMPS_ADVANCED_VPROG_MASK         0x3f

/* Buck TEST2 registers for shutdown/reset */
#define PM8058_S0_TEST2                         0x084
#define PM8058_S1_TEST2                         0x085
#define PM8058_S3_TEST2                         0x11a

#define PM8058_REGULATOR_BANK_WRITE             0x80
#define PM8058_REGULATOR_BANK_MASK              0x70
#define PM8058_REGULATOR_BANK_SHIFT             4
#define PM8058_REGULATOR_BANK_SEL(n)    ((n) << PM8058_REGULATOR_BANK_SHIFT)

/* Buck TEST2 register bank 1 */
#define PM8058_SMPS_LEGACY_VLOW_SEL             0x01

/* Buck TEST2 register bank 7 */
#define PM8058_SMPS_ADVANCED_MODE_MASK          0x02
#define PM8058_SMPS_ADVANCED_MODE               0x02
#define PM8058_SMPS_LEGACY_MODE                 0x00

/**
 * struct pmic8xxx_pwrkey - pmic8xxx pwrkey information
 * @key_press_irq: key press irq number
 * @regmap: device regmap
 * @shutdown_fn: shutdown configuration function
 */
struct pmic8xxx_pwrkey {
        int key_press_irq;
        struct regmap *regmap;
        int (*shutdown_fn)(struct pmic8xxx_pwrkey *, bool);
};

static irqreturn_t pwrkey_press_irq(int irq, void *_pwr)
{
        struct input_dev *pwr = _pwr;

        input_report_key(pwr, KEY_POWER, 1);
        input_sync(pwr);

        return IRQ_HANDLED;
}

static irqreturn_t pwrkey_release_irq(int irq, void *_pwr)
{
        struct input_dev *pwr = _pwr;

        input_report_key(pwr, KEY_POWER, 0);
        input_sync(pwr);

        return IRQ_HANDLED;
}

static int pmic8xxx_pwrkey_suspend(struct device *dev)
{
        struct pmic8xxx_pwrkey *pwrkey = dev_get_drvdata(dev);

        if (device_may_wakeup(dev))
                enable_irq_wake(pwrkey->key_press_irq);

        return 0;
}

static int pmic8xxx_pwrkey_resume(struct device *dev)
{
        struct pmic8xxx_pwrkey *pwrkey = dev_get_drvdata(dev);

        if (device_may_wakeup(dev))
                disable_irq_wake(pwrkey->key_press_irq);

        return 0;
}

static DEFINE_SIMPLE_DEV_PM_OPS(pm8xxx_pwr_key_pm_ops,
                pmic8xxx_pwrkey_suspend, pmic8xxx_pwrkey_resume);

static void pmic8xxx_pwrkey_shutdown(struct platform_device *pdev)
{
        struct pmic8xxx_pwrkey *pwrkey = platform_get_drvdata(pdev);
        int error;
        u8 mask, val;
        bool reset = system_state == SYSTEM_RESTART;

        if (pwrkey->shutdown_fn) {
                error = pwrkey->shutdown_fn(pwrkey, reset);
                if (error)
                        return;
        }

        /*
         * Select action to perform (reset or shutdown) when PS_HOLD goes low.
         * Also ensure that KPD, CBL0, and CBL1 pull ups are enabled and that
         * USB charging is enabled.
         */
        mask = PON_CNTL_1_PULL_UP_EN | PON_CNTL_1_USB_PWR_EN;
        mask |= PON_CNTL_1_WD_EN_RESET;
        val = mask;
        if (!reset)
                val &= ~PON_CNTL_1_WD_EN_RESET;

        regmap_update_bits(pwrkey->regmap, PON_CNTL_1, mask, val);
}

/*
 * Set an SMPS regulator to be disabled in its CTRL register, but enabled
 * in the master enable register.  Also set it's pull down enable bit.
 * Take care to make sure that the output voltage doesn't change if switching
 * from advanced mode to legacy mode.
 */
static int pm8058_disable_smps_locally_set_pull_down(struct regmap *regmap,
        u16 ctrl_addr, u16 test2_addr, u16 master_enable_addr,
        u8 master_enable_bit)
{
        int error;
        u8 vref_sel, vlow_sel, band, vprog, bank;
        unsigned int reg;

        bank = PM8058_REGULATOR_BANK_SEL(7);
        error = regmap_write(regmap, test2_addr, bank);
        if (error)
                return error;

        error = regmap_read(regmap, test2_addr, &reg);
        if (error)
                return error;

        reg &= PM8058_SMPS_ADVANCED_MODE_MASK;
        /* Check if in advanced mode. */
        if (reg == PM8058_SMPS_ADVANCED_MODE) {
                /* Determine current output voltage. */
                error = regmap_read(regmap, ctrl_addr, &reg);
                if (error)
                        return error;

                band = reg & PM8058_SMPS_ADVANCED_BAND_MASK;
                band >>= PM8058_SMPS_ADVANCED_BAND_SHIFT;
                switch (band) {
                case 3:
                        vref_sel = 0;
                        vlow_sel = 0;
                        break;
                case 2:
                        vref_sel = PM8058_SMPS_LEGACY_VREF_SEL;
                        vlow_sel = 0;
                        break;
                case 1:
                        vref_sel = PM8058_SMPS_LEGACY_VREF_SEL;
                        vlow_sel = PM8058_SMPS_LEGACY_VLOW_SEL;
                        break;
                default:
                        pr_err("%s: regulator already disabled\n", __func__);
                        return -EPERM;
                }
                vprog = reg & PM8058_SMPS_ADVANCED_VPROG_MASK;
                /* Round up if fine step is in use. */
                vprog = (vprog + 1) >> 1;
                if (vprog > PM8058_SMPS_LEGACY_VPROG_MASK)
                        vprog = PM8058_SMPS_LEGACY_VPROG_MASK;

                /* Set VLOW_SEL bit. */
                bank = PM8058_REGULATOR_BANK_SEL(1);
                error = regmap_write(regmap, test2_addr, bank);
                if (error)
                        return error;

                error = regmap_update_bits(regmap, test2_addr,
                        PM8058_REGULATOR_BANK_WRITE | PM8058_REGULATOR_BANK_MASK
                                | PM8058_SMPS_LEGACY_VLOW_SEL,
                        PM8058_REGULATOR_BANK_WRITE |
                        PM8058_REGULATOR_BANK_SEL(1) | vlow_sel);
                if (error)
                        return error;

                /* Switch to legacy mode */
                bank = PM8058_REGULATOR_BANK_SEL(7);
                error = regmap_write(regmap, test2_addr, bank);
                if (error)
                        return error;

                error = regmap_update_bits(regmap, test2_addr,
                                PM8058_REGULATOR_BANK_WRITE |
                                PM8058_REGULATOR_BANK_MASK |
                                PM8058_SMPS_ADVANCED_MODE_MASK,
                                PM8058_REGULATOR_BANK_WRITE |
                                PM8058_REGULATOR_BANK_SEL(7) |
                                PM8058_SMPS_LEGACY_MODE);
                if (error)
                        return error;

                /* Enable locally, enable pull down, keep voltage the same. */
                error = regmap_update_bits(regmap, ctrl_addr,
                        PM8058_REGULATOR_ENABLE_MASK |
                        PM8058_REGULATOR_PULL_DOWN_MASK |
                        PM8058_SMPS_LEGACY_VREF_SEL |
                        PM8058_SMPS_LEGACY_VPROG_MASK,
                        PM8058_REGULATOR_ENABLE | PM8058_REGULATOR_PULL_DOWN_EN
                                | vref_sel | vprog);
                if (error)
                        return error;
        }

        /* Enable in master control register. */
        error = regmap_update_bits(regmap, master_enable_addr,
                        master_enable_bit, master_enable_bit);
        if (error)
                return error;

        /* Disable locally and enable pull down. */
        return regmap_update_bits(regmap, ctrl_addr,
                PM8058_REGULATOR_ENABLE_MASK | PM8058_REGULATOR_PULL_DOWN_MASK,
                PM8058_REGULATOR_DISABLE | PM8058_REGULATOR_PULL_DOWN_EN);
}

static int pm8058_disable_ldo_locally_set_pull_down(struct regmap *regmap,
                u16 ctrl_addr, u16 master_enable_addr, u8 master_enable_bit)
{
        int error;

        /* Enable LDO in master control register. */
        error = regmap_update_bits(regmap, master_enable_addr,
                        master_enable_bit, master_enable_bit);
        if (error)
                return error;

        /* Disable LDO in CTRL register and set pull down */
        return regmap_update_bits(regmap, ctrl_addr,
                PM8058_REGULATOR_ENABLE_MASK | PM8058_REGULATOR_PULL_DOWN_MASK,
                PM8058_REGULATOR_DISABLE | PM8058_REGULATOR_PULL_DOWN_EN);
}

static int pm8058_pwrkey_shutdown(struct pmic8xxx_pwrkey *pwrkey, bool reset)
{
        int error;
        struct regmap *regmap = pwrkey->regmap;
        u8 mask, val;

        /* When shutting down, enable active pulldowns on important rails. */
        if (!reset) {
                /* Disable SMPS's 0,1,3 locally and set pulldown enable bits. */
                pm8058_disable_smps_locally_set_pull_down(regmap,
                        PM8058_S0_CTRL, PM8058_S0_TEST2,
                        REG_PM8058_VREG_EN_MSM, BIT(7));
                pm8058_disable_smps_locally_set_pull_down(regmap,
                        PM8058_S1_CTRL, PM8058_S1_TEST2,
                        REG_PM8058_VREG_EN_MSM, BIT(6));
                pm8058_disable_smps_locally_set_pull_down(regmap,
                        PM8058_S3_CTRL, PM8058_S3_TEST2,
                        REG_PM8058_VREG_EN_GRP_5_4, BIT(7) | BIT(4));
                /* Disable LDO 21 locally and set pulldown enable bit. */
                pm8058_disable_ldo_locally_set_pull_down(regmap,
                        PM8058_L21_CTRL, REG_PM8058_VREG_EN_GRP_5_4,
                        BIT(1));
        }

        /*
         * Fix-up: Set regulator LDO22 to 1.225 V in high power mode. Leave its
         * pull-down state intact. This ensures a safe shutdown.
         */
        error = regmap_update_bits(regmap, PM8058_L22_CTRL, 0xbf, 0x93);
        if (error)
                return error;

        /* Enable SMPL if resetting is desired */
        mask = SLEEP_CTRL_SMPL_EN_RESET;
        val = 0;
        if (reset)
                val = mask;
        return regmap_update_bits(regmap, PM8058_SLEEP_CTRL, mask, val);
}

static int pm8921_pwrkey_shutdown(struct pmic8xxx_pwrkey *pwrkey, bool reset)
{
        struct regmap *regmap = pwrkey->regmap;
        u8 mask = SLEEP_CTRL_SMPL_EN_RESET;
        u8 val = 0;

        /* Enable SMPL if resetting is desired */
        if (reset)
                val = mask;
        return regmap_update_bits(regmap, PM8921_SLEEP_CTRL, mask, val);
}

static int pmic8xxx_pwrkey_probe(struct platform_device *pdev)
{
        struct input_dev *pwr;
        int key_release_irq = platform_get_irq(pdev, 0);
        int key_press_irq = platform_get_irq(pdev, 1);
        int err;
        unsigned int delay;
        unsigned int pon_cntl;
        struct regmap *regmap;
        struct pmic8xxx_pwrkey *pwrkey;
        u32 kpd_delay;
        bool pull_up;

        if (of_property_read_u32(pdev->dev.of_node, "debounce", &kpd_delay))
                kpd_delay = 15625;

        /* Valid range of pwr key trigger delay is 1/64 sec to 2 seconds. */
        if (kpd_delay > USEC_PER_SEC * 2 || kpd_delay < USEC_PER_SEC / 64) {
                dev_err(&pdev->dev, "invalid power key trigger delay\n");
                return -EINVAL;
        }

        pull_up = of_property_read_bool(pdev->dev.of_node, "pull-up");

        regmap = dev_get_regmap(pdev->dev.parent, NULL);
        if (!regmap) {
                dev_err(&pdev->dev, "failed to locate regmap for the device\n");
                return -ENODEV;
        }

        pwrkey = devm_kzalloc(&pdev->dev, sizeof(*pwrkey), GFP_KERNEL);
        if (!pwrkey)
                return -ENOMEM;

        pwrkey->shutdown_fn = of_device_get_match_data(&pdev->dev);
        pwrkey->regmap = regmap;
        pwrkey->key_press_irq = key_press_irq;

        pwr = devm_input_allocate_device(&pdev->dev);
        if (!pwr) {
                dev_dbg(&pdev->dev, "Can't allocate power button\n");
                return -ENOMEM;
        }

        input_set_capability(pwr, EV_KEY, KEY_POWER);

        pwr->name = "pmic8xxx_pwrkey";
        pwr->phys = "pmic8xxx_pwrkey/input0";

        delay = (kpd_delay << 6) / USEC_PER_SEC;
        delay = ilog2(delay);

        err = regmap_read(regmap, PON_CNTL_1, &pon_cntl);
        if (err < 0) {
                dev_err(&pdev->dev, "failed reading PON_CNTL_1 err=%d\n", err);
                return err;
        }

        pon_cntl &= ~PON_CNTL_TRIG_DELAY_MASK;
        pon_cntl |= (delay & PON_CNTL_TRIG_DELAY_MASK);
        if (pull_up)
                pon_cntl |= PON_CNTL_PULL_UP;
        else
                pon_cntl &= ~PON_CNTL_PULL_UP;

        err = regmap_write(regmap, PON_CNTL_1, pon_cntl);
        if (err < 0) {
                dev_err(&pdev->dev, "failed writing PON_CNTL_1 err=%d\n", err);
                return err;
        }

        err = devm_request_irq(&pdev->dev, key_press_irq, pwrkey_press_irq,
                               IRQF_TRIGGER_RISING,
                               "pmic8xxx_pwrkey_press", pwr);
        if (err) {
                dev_err(&pdev->dev, "Can't get %d IRQ for pwrkey: %d\n",
                        key_press_irq, err);
                return err;
        }

        err = devm_request_irq(&pdev->dev, key_release_irq, pwrkey_release_irq,
                               IRQF_TRIGGER_RISING,
                               "pmic8xxx_pwrkey_release", pwr);
        if (err) {
                dev_err(&pdev->dev, "Can't get %d IRQ for pwrkey: %d\n",
                        key_release_irq, err);
                return err;
        }

        err = input_register_device(pwr);
        if (err) {
                dev_err(&pdev->dev, "Can't register power key: %d\n", err);
                return err;
        }

        platform_set_drvdata(pdev, pwrkey);
        device_init_wakeup(&pdev->dev, 1);

        return 0;
}

static const struct of_device_id pm8xxx_pwr_key_id_table[] = {
        { .compatible = "qcom,pm8058-pwrkey", .data = &pm8058_pwrkey_shutdown },
        { .compatible = "qcom,pm8921-pwrkey", .data = &pm8921_pwrkey_shutdown },
        { }
};
MODULE_DEVICE_TABLE(of, pm8xxx_pwr_key_id_table);

static struct platform_driver pmic8xxx_pwrkey_driver = {
        .probe          = pmic8xxx_pwrkey_probe,
        .shutdown       = pmic8xxx_pwrkey_shutdown,
        .driver         = {
                .name   = "pm8xxx-pwrkey",
                .pm     = pm_sleep_ptr(&pm8xxx_pwr_key_pm_ops),
                .of_match_table = pm8xxx_pwr_key_id_table,
        },
};
module_platform_driver(pmic8xxx_pwrkey_driver);

MODULE_ALIAS("platform:pmic8xxx_pwrkey");
MODULE_DESCRIPTION("PMIC8XXX Power Key driver");
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Trilok Soni <tsoni@codeaurora.org>");