root/drivers/extcon/extcon-palmas.c
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Palmas USB transceiver driver
 *
 * Copyright (C) 2013 Texas Instruments Incorporated - https://www.ti.com
 * 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>
 */

#include <linux/devm-helpers.h>
#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/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_state_sync(edev, EXTCON_USB, true);
                        dev_dbg(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_state_sync(edev, EXTCON_USB, false);
                        dev_dbg(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_state_sync(edev, EXTCON_USB_HOST, true);
                dev_dbg(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_state_sync(edev, EXTCON_USB_HOST, false);
                dev_dbg(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_state_sync(edev, EXTCON_USB_HOST, false);
                dev_dbg(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_state_sync(edev, EXTCON_USB_HOST, true);
                dev_dbg(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_state_sync(edev, EXTCON_USB_HOST, false);
                dev_dbg(palmas_usb->dev, "USB-HOST cable is detached\n");
        } else {
                extcon_set_state_sync(edev, EXTCON_USB_HOST, true);
                dev_dbg(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;

        if (!palmas) {
                dev_err(&pdev->dev, "failed to get valid parent\n");
                return -EINVAL;
        }

        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))
                return dev_err_probe(&pdev->dev, PTR_ERR(palmas_usb->id_gpiod),
                                     "failed to get id gpio\n");

        palmas_usb->vbus_gpiod = devm_gpiod_get_optional(&pdev->dev, "vbus",
                                                        GPIOD_IN);
        if (IS_ERR(palmas_usb->vbus_gpiod))
                return dev_err_probe(&pdev->dev, PTR_ERR(palmas_usb->vbus_gpiod),
                                     "failed to get id gpio\n");

        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_vbus_detection && palmas_usb->vbus_gpiod) {
                palmas_usb->enable_vbus_detection = false;
                palmas_usb->enable_gpio_vbus_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);
        }

        status = devm_delayed_work_autocancel(&pdev->dev,
                                              &palmas_usb->wq_detectid,
                                              palmas_gpio_id_detect);
        if (status)
                return status;

        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,
                                "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,
                                "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;
                }
        } else if (palmas_usb->enable_gpio_vbus_detection) {
                /* remux GPIO_1 as VBUSDET */
                status = palmas_update_bits(palmas,
                        PALMAS_PU_PD_OD_BASE,
                        PALMAS_PRIMARY_SECONDARY_PAD1,
                        PALMAS_PRIMARY_SECONDARY_PAD1_GPIO_1_MASK,
                        (1 << PALMAS_PRIMARY_SECONDARY_PAD1_GPIO_1_SHIFT));
                if (status < 0) {
                        dev_err(&pdev->dev, "can't remux GPIO1\n");
                        return status;
                }

                palmas_usb->vbus_otg_irq = regmap_irq_get_virq(palmas->irq_data,
                                                       PALMAS_VBUS_OTG_IRQ);
                palmas_usb->gpio_vbus_irq = gpiod_to_irq(palmas_usb->vbus_gpiod);
                if (palmas_usb->gpio_vbus_irq < 0) {
                        dev_err(&pdev->dev, "failed to get vbus irq\n");
                        return palmas_usb->gpio_vbus_irq;
                }
                status = devm_request_threaded_irq(&pdev->dev,
                                                palmas_usb->gpio_vbus_irq,
                                                NULL,
                                                palmas_vbus_irq_handler,
                                                IRQF_TRIGGER_FALLING |
                                                IRQF_TRIGGER_RISING |
                                                IRQF_ONESHOT,
                                                "palmas_usb_vbus",
                                                palmas_usb);
                if (status < 0) {
                        dev_err(&pdev->dev,
                                "failed to request handler for vbus irq\n");
                        return status;
                }
        }

        palmas_enable_irq(palmas_usb);
        /* perform initial detection */
        if (palmas_usb->enable_gpio_vbus_detection)
                palmas_vbus_irq_handler(palmas_usb->gpio_vbus_irq, palmas_usb);
        palmas_gpio_id_detect(&palmas_usb->wq_detectid.work);
        device_set_wakeup_capable(&pdev->dev, true);
        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_gpio_vbus_detection)
                        enable_irq_wake(palmas_usb->gpio_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_gpio_vbus_detection)
                        disable_irq_wake(palmas_usb->gpio_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);
        }

        /* check if GPIO states changed while suspend/resume */
        if (palmas_usb->enable_gpio_vbus_detection)
                palmas_vbus_irq_handler(palmas_usb->gpio_vbus_irq, palmas_usb);
        palmas_gpio_id_detect(&palmas_usb->wq_detectid.work);

        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,
        .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);