// SPDX-License-Identifier: GPL-2.0-only
/*
 * extcon-qcom-spmi-misc.c - Qualcomm USB extcon driver to support USB ID
 *                      and VBUS detection based on extcon-usb-gpio.c.
 *
 * Copyright (C) 2016 Linaro, Ltd.
 * Stephen Boyd <stephen.boyd@linaro.org>
 */

#include <linux/devm-helpers.h>
#include <linux/extcon-provider.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/mod_devicetable.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/workqueue.h>

#define USB_ID_DEBOUNCE_MS      5       /* ms */

struct qcom_usb_extcon_info {
        struct extcon_dev *edev;
        int id_irq;
        int vbus_irq;
        struct delayed_work wq_detcable;
        unsigned long debounce_jiffies;
};

static const unsigned int qcom_usb_extcon_cable[] = {
        EXTCON_USB,
        EXTCON_USB_HOST,
        EXTCON_NONE,
};

static void qcom_usb_extcon_detect_cable(struct work_struct *work)
{
        bool state = false;
        int ret;
        union extcon_property_value val;
        struct qcom_usb_extcon_info *info = container_of(to_delayed_work(work),
                                                    struct qcom_usb_extcon_info,
                                                    wq_detcable);

        if (info->id_irq > 0) {
                /* check ID and update cable state */
                ret = irq_get_irqchip_state(info->id_irq,
                                IRQCHIP_STATE_LINE_LEVEL, &state);
                if (ret)
                        return;

                if (!state) {
                        val.intval = true;
                        extcon_set_property(info->edev, EXTCON_USB_HOST,
                                                EXTCON_PROP_USB_SS, val);
                }
                extcon_set_state_sync(info->edev, EXTCON_USB_HOST, !state);
        }

        if (info->vbus_irq > 0) {
                /* check VBUS and update cable state */
                ret = irq_get_irqchip_state(info->vbus_irq,
                                IRQCHIP_STATE_LINE_LEVEL, &state);
                if (ret)
                        return;

                if (state) {
                        val.intval = true;
                        extcon_set_property(info->edev, EXTCON_USB,
                                                EXTCON_PROP_USB_SS, val);
                }
                extcon_set_state_sync(info->edev, EXTCON_USB, state);
        }
}

static irqreturn_t qcom_usb_irq_handler(int irq, void *dev_id)
{
        struct qcom_usb_extcon_info *info = dev_id;

        queue_delayed_work(system_power_efficient_wq, &info->wq_detcable,
                           info->debounce_jiffies);

        return IRQ_HANDLED;
}

static int qcom_usb_extcon_probe(struct platform_device *pdev)
{
        struct device *dev = &pdev->dev;
        struct qcom_usb_extcon_info *info;
        int ret;

        info = devm_kzalloc(dev, sizeof(*info), GFP_KERNEL);
        if (!info)
                return -ENOMEM;

        info->edev = devm_extcon_dev_allocate(dev, qcom_usb_extcon_cable);
        if (IS_ERR(info->edev)) {
                dev_err(dev, "failed to allocate extcon device\n");
                return -ENOMEM;
        }

        ret = devm_extcon_dev_register(dev, info->edev);
        if (ret < 0) {
                dev_err(dev, "failed to register extcon device\n");
                return ret;
        }

        ret = extcon_set_property_capability(info->edev,
                        EXTCON_USB, EXTCON_PROP_USB_SS);
        ret |= extcon_set_property_capability(info->edev,
                        EXTCON_USB_HOST, EXTCON_PROP_USB_SS);
        if (ret) {
                dev_err(dev, "failed to register extcon props rc=%d\n",
                                                ret);
                return ret;
        }

        info->debounce_jiffies = msecs_to_jiffies(USB_ID_DEBOUNCE_MS);

        ret = devm_delayed_work_autocancel(dev, &info->wq_detcable,
                                           qcom_usb_extcon_detect_cable);
        if (ret)
                return ret;

        info->id_irq = platform_get_irq_byname_optional(pdev, "usb_id");
        if (info->id_irq > 0) {
                ret = devm_request_threaded_irq(dev, info->id_irq, NULL,
                                        qcom_usb_irq_handler,
                                        IRQF_TRIGGER_RISING |
                                        IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
                                        pdev->name, info);
                if (ret < 0) {
                        dev_err(dev, "failed to request handler for ID IRQ\n");
                        return ret;
                }
        }

        info->vbus_irq = platform_get_irq_byname_optional(pdev, "usb_vbus");
        if (info->vbus_irq > 0) {
                ret = devm_request_threaded_irq(dev, info->vbus_irq, NULL,
                                        qcom_usb_irq_handler,
                                        IRQF_TRIGGER_RISING |
                                        IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
                                        pdev->name, info);
                if (ret < 0) {
                        dev_err(dev, "failed to request handler for VBUS IRQ\n");
                        return ret;
                }
        }

        if (info->id_irq < 0 && info->vbus_irq < 0) {
                dev_err(dev, "ID and VBUS IRQ not found\n");
                return -EINVAL;
        }

        platform_set_drvdata(pdev, info);
        devm_device_init_wakeup(dev);

        /* Perform initial detection */
        qcom_usb_extcon_detect_cable(&info->wq_detcable.work);

        return 0;
}

#ifdef CONFIG_PM_SLEEP
static int qcom_usb_extcon_suspend(struct device *dev)
{
        struct qcom_usb_extcon_info *info = dev_get_drvdata(dev);
        int ret = 0;

        if (device_may_wakeup(dev)) {
                if (info->id_irq > 0)
                        ret = enable_irq_wake(info->id_irq);
                if (info->vbus_irq > 0)
                        ret = enable_irq_wake(info->vbus_irq);
        }

        return ret;
}

static int qcom_usb_extcon_resume(struct device *dev)
{
        struct qcom_usb_extcon_info *info = dev_get_drvdata(dev);
        int ret = 0;

        if (device_may_wakeup(dev)) {
                if (info->id_irq > 0)
                        ret = disable_irq_wake(info->id_irq);
                if (info->vbus_irq > 0)
                        ret = disable_irq_wake(info->vbus_irq);
        }

        return ret;
}
#endif

static SIMPLE_DEV_PM_OPS(qcom_usb_extcon_pm_ops,
                         qcom_usb_extcon_suspend, qcom_usb_extcon_resume);

static const struct of_device_id qcom_usb_extcon_dt_match[] = {
        { .compatible = "qcom,pm8941-misc", },
        { }
};
MODULE_DEVICE_TABLE(of, qcom_usb_extcon_dt_match);

static struct platform_driver qcom_usb_extcon_driver = {
        .probe          = qcom_usb_extcon_probe,
        .driver         = {
                .name   = "extcon-pm8941-misc",
                .pm     = &qcom_usb_extcon_pm_ops,
                .of_match_table = qcom_usb_extcon_dt_match,
        },
};
module_platform_driver(qcom_usb_extcon_driver);

MODULE_DESCRIPTION("QCOM USB ID extcon driver");
MODULE_AUTHOR("Stephen Boyd <stephen.boyd@linaro.org>");
MODULE_LICENSE("GPL v2");