/*
 * Palmas USB transceiver driver
 *
 * Copyright (C) 2013 Texas Instruments Incorporated - http://www.ti.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.
 *
 * Author: Graeme Gregory <gg@slimlogic.co.uk>
 * Author: Kishon Vijay Abraham I <kishon@ti.com>
 *
 * Based on twl6030_usb.c
 *
 * Author: Hema HK <hemahk@ti.com>
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/err.h>
#include <linux/mfd/palmas.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/of_gpio.h>
#include <linux/gpio/consumer.h>
#include <linux/workqueue.h>

#define USB_GPIO_DEBOUNCE_MS	20	/* ms */

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

static void palmas_usb_wakeup(struct palmas *palmas, int enable)
{
	if (enable)
		palmas_write(palmas, PALMAS_USB_OTG_BASE, PALMAS_USB_WAKEUP,
			PALMAS_USB_WAKEUP_ID_WK_UP_COMP);
	else
		palmas_write(palmas, PALMAS_USB_OTG_BASE, PALMAS_USB_WAKEUP, 0);
}

static irqreturn_t palmas_vbus_irq_handler(int irq, void *_palmas_usb)
{
	struct palmas_usb *palmas_usb = _palmas_usb;
	struct extcon_dev *edev = palmas_usb->edev;
	unsigned int vbus_line_state;

	palmas_read(palmas_usb->palmas, PALMAS_INTERRUPT_BASE,
		PALMAS_INT3_LINE_STATE, &vbus_line_state);

	if (vbus_line_state & PALMAS_INT3_LINE_STATE_VBUS) {
		if (palmas_usb->linkstat != PALMAS_USB_STATE_VBUS) {
			palmas_usb->linkstat = PALMAS_USB_STATE_VBUS;
			extcon_set_cable_state_(edev, EXTCON_USB, true);
			dev_info(palmas_usb->dev, "USB cable is attached\n");
		} else {
			dev_dbg(palmas_usb->dev,
				"Spurious connect event detected\n");
		}
	} else if (!(vbus_line_state & PALMAS_INT3_LINE_STATE_VBUS)) {
		if (palmas_usb->linkstat == PALMAS_USB_STATE_VBUS) {
			palmas_usb->linkstat = PALMAS_USB_STATE_DISCONNECT;
			extcon_set_cable_state_(edev, EXTCON_USB, false);
			dev_info(palmas_usb->dev, "USB cable is detached\n");
		} else {
			dev_dbg(palmas_usb->dev,
				"Spurious disconnect event detected\n");
		}
	}

	return IRQ_HANDLED;
}

static irqreturn_t palmas_id_irq_handler(int irq, void *_palmas_usb)
{
	unsigned int set, id_src;
	struct palmas_usb *palmas_usb = _palmas_usb;
	struct extcon_dev *edev = palmas_usb->edev;

	palmas_read(palmas_usb->palmas, PALMAS_USB_OTG_BASE,
		PALMAS_USB_ID_INT_LATCH_SET, &set);
	palmas_read(palmas_usb->palmas, PALMAS_USB_OTG_BASE,
		PALMAS_USB_ID_INT_SRC, &id_src);

	if ((set & PALMAS_USB_ID_INT_SRC_ID_GND) &&
				(id_src & PALMAS_USB_ID_INT_SRC_ID_GND)) {
		palmas_write(palmas_usb->palmas, PALMAS_USB_OTG_BASE,
			PALMAS_USB_ID_INT_LATCH_CLR,
			PALMAS_USB_ID_INT_EN_HI_CLR_ID_GND);
		palmas_usb->linkstat = PALMAS_USB_STATE_ID;
		extcon_set_cable_state_(edev, EXTCON_USB_HOST, true);
		dev_info(palmas_usb->dev, "USB-HOST cable is attached\n");
	} else if ((set & PALMAS_USB_ID_INT_SRC_ID_FLOAT) &&
				(id_src & PALMAS_USB_ID_INT_SRC_ID_FLOAT)) {
		palmas_write(palmas_usb->palmas, PALMAS_USB_OTG_BASE,
			PALMAS_USB_ID_INT_LATCH_CLR,
			PALMAS_USB_ID_INT_EN_HI_CLR_ID_FLOAT);
		palmas_usb->linkstat = PALMAS_USB_STATE_DISCONNECT;
		extcon_set_cable_state_(edev, EXTCON_USB_HOST, false);
		dev_info(palmas_usb->dev, "USB-HOST cable is detached\n");
	} else if ((palmas_usb->linkstat == PALMAS_USB_STATE_ID) &&
				(!(set & PALMAS_USB_ID_INT_SRC_ID_GND))) {
		palmas_usb->linkstat = PALMAS_USB_STATE_DISCONNECT;
		extcon_set_cable_state_(edev, EXTCON_USB_HOST, false);
		dev_info(palmas_usb->dev, "USB-HOST cable is detached\n");
	} else if ((palmas_usb->linkstat == PALMAS_USB_STATE_DISCONNECT) &&
				(id_src & PALMAS_USB_ID_INT_SRC_ID_GND)) {
		palmas_usb->linkstat = PALMAS_USB_STATE_ID;
		extcon_set_cable_state_(edev, EXTCON_USB_HOST, true);
		dev_info(palmas_usb->dev, " USB-HOST cable is attached\n");
	}

	return IRQ_HANDLED;
}

static void palmas_gpio_id_detect(struct work_struct *work)
{
	int id;
	struct palmas_usb *palmas_usb = container_of(to_delayed_work(work),
						     struct palmas_usb,
						     wq_detectid);
	struct extcon_dev *edev = palmas_usb->edev;

	if (!palmas_usb->id_gpiod)
		return;

	id = gpiod_get_value_cansleep(palmas_usb->id_gpiod);

	if (id) {
		extcon_set_cable_state_(edev, EXTCON_USB_HOST, false);
		dev_info(palmas_usb->dev, "USB-HOST cable is detached\n");
	} else {
		extcon_set_cable_state_(edev, EXTCON_USB_HOST, true);
		dev_info(palmas_usb->dev, "USB-HOST cable is attached\n");
	}
}

static irqreturn_t palmas_gpio_id_irq_handler(int irq, void *_palmas_usb)
{
	struct palmas_usb *palmas_usb = _palmas_usb;

	queue_delayed_work(system_power_efficient_wq, &palmas_usb->wq_detectid,
			   palmas_usb->sw_debounce_jiffies);

	return IRQ_HANDLED;
}

static void palmas_enable_irq(struct palmas_usb *palmas_usb)
{
	palmas_write(palmas_usb->palmas, PALMAS_USB_OTG_BASE,
		PALMAS_USB_VBUS_CTRL_SET,
		PALMAS_USB_VBUS_CTRL_SET_VBUS_ACT_COMP);

	if (palmas_usb->enable_id_detection) {
		palmas_write(palmas_usb->palmas, PALMAS_USB_OTG_BASE,
			     PALMAS_USB_ID_CTRL_SET,
			     PALMAS_USB_ID_CTRL_SET_ID_ACT_COMP);

		palmas_write(palmas_usb->palmas, PALMAS_USB_OTG_BASE,
			     PALMAS_USB_ID_INT_EN_HI_SET,
			     PALMAS_USB_ID_INT_EN_HI_SET_ID_GND |
			     PALMAS_USB_ID_INT_EN_HI_SET_ID_FLOAT);
	}

	if (palmas_usb->enable_vbus_detection)
		palmas_vbus_irq_handler(palmas_usb->vbus_irq, palmas_usb);

	/* cold plug for host mode needs this delay */
	if (palmas_usb->enable_id_detection) {
		msleep(30);
		palmas_id_irq_handler(palmas_usb->id_irq, palmas_usb);
	}
}

static int palmas_usb_probe(struct platform_device *pdev)
{
	struct palmas *palmas = dev_get_drvdata(pdev->dev.parent);
	struct palmas_usb_platform_data	*pdata = dev_get_platdata(&pdev->dev);
	struct device_node *node = pdev->dev.of_node;
	struct palmas_usb *palmas_usb;
	int status;

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

	if (node && !pdata) {
		palmas_usb->wakeup = of_property_read_bool(node, "ti,wakeup");
		palmas_usb->enable_id_detection = of_property_read_bool(node,
						"ti,enable-id-detection");
		palmas_usb->enable_vbus_detection = of_property_read_bool(node,
						"ti,enable-vbus-detection");
	} else {
		palmas_usb->wakeup = true;
		palmas_usb->enable_id_detection = true;
		palmas_usb->enable_vbus_detection = true;

		if (pdata)
			palmas_usb->wakeup = pdata->wakeup;
	}

	palmas_usb->id_gpiod = devm_gpiod_get_optional(&pdev->dev, "id",
							GPIOD_IN);
	if (IS_ERR(palmas_usb->id_gpiod)) {
		dev_err(&pdev->dev, "failed to get id gpio\n");
		return PTR_ERR(palmas_usb->id_gpiod);
	}

	if (palmas_usb->enable_id_detection && palmas_usb->id_gpiod) {
		palmas_usb->enable_id_detection = false;
		palmas_usb->enable_gpio_id_detection = true;
	}

	if (palmas_usb->enable_gpio_id_detection) {
		u32 debounce;

		if (of_property_read_u32(node, "debounce-delay-ms", &debounce))
			debounce = USB_GPIO_DEBOUNCE_MS;

		status = gpiod_set_debounce(palmas_usb->id_gpiod,
					    debounce * 1000);
		if (status < 0)
			palmas_usb->sw_debounce_jiffies = msecs_to_jiffies(debounce);
	}

	INIT_DELAYED_WORK(&palmas_usb->wq_detectid, palmas_gpio_id_detect);

	palmas->usb = palmas_usb;
	palmas_usb->palmas = palmas;

	palmas_usb->dev	 = &pdev->dev;

	palmas_usb_wakeup(palmas, palmas_usb->wakeup);

	platform_set_drvdata(pdev, palmas_usb);

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

	status = devm_extcon_dev_register(&pdev->dev, palmas_usb->edev);
	if (status) {
		dev_err(&pdev->dev, "failed to register extcon device\n");
		return status;
	}

	if (palmas_usb->enable_id_detection) {
		palmas_usb->id_otg_irq = regmap_irq_get_virq(palmas->irq_data,
							     PALMAS_ID_OTG_IRQ);
		palmas_usb->id_irq = regmap_irq_get_virq(palmas->irq_data,
							 PALMAS_ID_IRQ);
		status = devm_request_threaded_irq(palmas_usb->dev,
				palmas_usb->id_irq,
				NULL, palmas_id_irq_handler,
				IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING |
				IRQF_ONESHOT | IRQF_EARLY_RESUME,
				"palmas_usb_id", palmas_usb);
		if (status < 0) {
			dev_err(&pdev->dev, "can't get IRQ %d, err %d\n",
					palmas_usb->id_irq, status);
			return status;
		}
	} else if (palmas_usb->enable_gpio_id_detection) {
		palmas_usb->gpio_id_irq = gpiod_to_irq(palmas_usb->id_gpiod);
		if (palmas_usb->gpio_id_irq < 0) {
			dev_err(&pdev->dev, "failed to get id irq\n");
			return palmas_usb->gpio_id_irq;
		}
		status = devm_request_threaded_irq(&pdev->dev,
						   palmas_usb->gpio_id_irq,
						   NULL,
						   palmas_gpio_id_irq_handler,
						   IRQF_TRIGGER_RISING |
						   IRQF_TRIGGER_FALLING |
						   IRQF_ONESHOT,
						   "palmas_usb_id",
						   palmas_usb);
		if (status < 0) {
			dev_err(&pdev->dev,
				"failed to request handler for id irq\n");
			return status;
		}
	}

	if (palmas_usb->enable_vbus_detection) {
		palmas_usb->vbus_otg_irq = regmap_irq_get_virq(palmas->irq_data,
						       PALMAS_VBUS_OTG_IRQ);
		palmas_usb->vbus_irq = regmap_irq_get_virq(palmas->irq_data,
							   PALMAS_VBUS_IRQ);
		status = devm_request_threaded_irq(palmas_usb->dev,
				palmas_usb->vbus_irq, NULL,
				palmas_vbus_irq_handler,
				IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING |
				IRQF_ONESHOT | IRQF_EARLY_RESUME,
				"palmas_usb_vbus", palmas_usb);
		if (status < 0) {
			dev_err(&pdev->dev, "can't get IRQ %d, err %d\n",
					palmas_usb->vbus_irq, status);
			return status;
		}
	}

	palmas_enable_irq(palmas_usb);
	/* perform initial detection */
	palmas_gpio_id_detect(&palmas_usb->wq_detectid.work);
	device_set_wakeup_capable(&pdev->dev, true);
	return 0;
}

static int palmas_usb_remove(struct platform_device *pdev)
{
	struct palmas_usb *palmas_usb = platform_get_drvdata(pdev);

	cancel_delayed_work_sync(&palmas_usb->wq_detectid);

	return 0;
}

#ifdef CONFIG_PM_SLEEP
static int palmas_usb_suspend(struct device *dev)
{
	struct palmas_usb *palmas_usb = dev_get_drvdata(dev);

	if (device_may_wakeup(dev)) {
		if (palmas_usb->enable_vbus_detection)
			enable_irq_wake(palmas_usb->vbus_irq);
		if (palmas_usb->enable_id_detection)
			enable_irq_wake(palmas_usb->id_irq);
		if (palmas_usb->enable_gpio_id_detection)
			enable_irq_wake(palmas_usb->gpio_id_irq);
	}
	return 0;
}

static int palmas_usb_resume(struct device *dev)
{
	struct palmas_usb *palmas_usb = dev_get_drvdata(dev);

	if (device_may_wakeup(dev)) {
		if (palmas_usb->enable_vbus_detection)
			disable_irq_wake(palmas_usb->vbus_irq);
		if (palmas_usb->enable_id_detection)
			disable_irq_wake(palmas_usb->id_irq);
		if (palmas_usb->enable_gpio_id_detection)
			disable_irq_wake(palmas_usb->gpio_id_irq);
	}
	return 0;
};
#endif

static SIMPLE_DEV_PM_OPS(palmas_pm_ops, palmas_usb_suspend, palmas_usb_resume);

static const struct of_device_id of_palmas_match_tbl[] = {
	{ .compatible = "ti,palmas-usb", },
	{ .compatible = "ti,palmas-usb-vid", },
	{ .compatible = "ti,twl6035-usb", },
	{ .compatible = "ti,twl6035-usb-vid", },
	{ /* end */ }
};

static struct platform_driver palmas_usb_driver = {
	.probe = palmas_usb_probe,
	.remove = palmas_usb_remove,
	.driver = {
		.name = "palmas-usb",
		.of_match_table = of_palmas_match_tbl,
		.pm = &palmas_pm_ops,
	},
};

module_platform_driver(palmas_usb_driver);

MODULE_ALIAS("platform:palmas-usb");
MODULE_AUTHOR("Graeme Gregory <gg@slimlogic.co.uk>");
MODULE_DESCRIPTION("Palmas USB transceiver driver");
MODULE_LICENSE("GPL");
MODULE_DEVICE_TABLE(of, of_palmas_match_tbl);