root/drivers/extcon/extcon-ptn5150.c
// SPDX-License-Identifier: GPL-2.0+
//
// extcon-ptn5150.c - PTN5150 CC logic extcon driver to support USB detection
//
// Based on extcon-sm5502.c driver
// Copyright (c) 2018-2019 by Vijai Kumar K
// Author: Vijai Kumar K <vijaikumar.kanagarajan@gmail.com>
// Copyright (c) 2020 Krzysztof Kozlowski <krzk@kernel.org>

#include <linux/bitfield.h>
#include <linux/err.h>
#include <linux/i2c.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/regmap.h>
#include <linux/slab.h>
#include <linux/extcon-provider.h>
#include <linux/gpio/consumer.h>
#include <linux/usb/role.h>

/* PTN5150 registers */
#define PTN5150_REG_DEVICE_ID                   0x01
#define PTN5150_REG_CONTROL                     0x02
#define PTN5150_REG_INT_STATUS                  0x03
#define PTN5150_REG_CC_STATUS                   0x04
#define PTN5150_REG_CON_DET                     0x09
#define PTN5150_REG_VCONN_STATUS                0x0a
#define PTN5150_REG_RESET                       0x0b
#define PTN5150_REG_INT_MASK                    0x18
#define PTN5150_REG_INT_REG_STATUS              0x19
#define PTN5150_REG_END                         PTN5150_REG_INT_REG_STATUS

#define PTN5150_DFP_ATTACHED                    0x1
#define PTN5150_UFP_ATTACHED                    0x2

/* Define PTN5150 MASK/SHIFT constant */
#define PTN5150_REG_DEVICE_ID_VERSION           GENMASK(7, 3)
#define PTN5150_REG_DEVICE_ID_VENDOR            GENMASK(2, 0)

#define PTN5150_REG_CC_PORT_ATTACHMENT          GENMASK(4, 2)
#define PTN5150_REG_CC_VBUS_DETECTION           BIT(7)
#define PTN5150_REG_INT_CABLE_ATTACH_MASK       BIT(0)
#define PTN5150_REG_INT_CABLE_DETACH_MASK       BIT(1)

struct ptn5150_info {
        struct device *dev;
        struct extcon_dev *edev;
        struct i2c_client *i2c;
        struct regmap *regmap;
        struct gpio_desc *int_gpiod;
        struct gpio_desc *vbus_gpiod;
        int irq;
        struct work_struct irq_work;
        struct mutex mutex;
        struct usb_role_switch *role_sw;
};

/* List of detectable cables */
static const unsigned int ptn5150_extcon_cable[] = {
        EXTCON_USB,
        EXTCON_USB_HOST,
        EXTCON_NONE,
};

static const struct regmap_config ptn5150_regmap_config = {
        .reg_bits       = 8,
        .val_bits       = 8,
        .max_register   = PTN5150_REG_END,
};

static void ptn5150_check_state(struct ptn5150_info *info)
{
        unsigned int port_status, reg_data, vbus;
        enum usb_role usb_role = USB_ROLE_NONE;
        int ret;

        ret = regmap_read(info->regmap, PTN5150_REG_CC_STATUS, &reg_data);
        if (ret) {
                dev_err(info->dev, "failed to read CC STATUS %d\n", ret);
                return;
        }

        port_status = FIELD_GET(PTN5150_REG_CC_PORT_ATTACHMENT, reg_data);

        switch (port_status) {
        case PTN5150_DFP_ATTACHED:
                extcon_set_state_sync(info->edev, EXTCON_USB_HOST, false);
                gpiod_set_value_cansleep(info->vbus_gpiod, 0);
                extcon_set_state_sync(info->edev, EXTCON_USB, true);
                usb_role = USB_ROLE_DEVICE;
                break;
        case PTN5150_UFP_ATTACHED:
                extcon_set_state_sync(info->edev, EXTCON_USB, false);
                vbus = FIELD_GET(PTN5150_REG_CC_VBUS_DETECTION, reg_data);
                if (vbus)
                        gpiod_set_value_cansleep(info->vbus_gpiod, 0);
                else
                        gpiod_set_value_cansleep(info->vbus_gpiod, 1);

                extcon_set_state_sync(info->edev, EXTCON_USB_HOST, true);
                usb_role = USB_ROLE_HOST;
                break;
        default:
                break;
        }

        if (usb_role) {
                ret = usb_role_switch_set_role(info->role_sw, usb_role);
                if (ret)
                        dev_err(info->dev, "failed to set %s role: %d\n",
                                usb_role_string(usb_role), ret);
        }
}

static void ptn5150_irq_work(struct work_struct *work)
{
        struct ptn5150_info *info = container_of(work,
                        struct ptn5150_info, irq_work);
        int ret = 0;
        unsigned int int_status;

        if (!info->edev)
                return;

        mutex_lock(&info->mutex);

        /* Clear interrupt. Read would clear the register */
        ret = regmap_read(info->regmap, PTN5150_REG_INT_STATUS, &int_status);
        if (ret) {
                dev_err(info->dev, "failed to read INT STATUS %d\n", ret);
                mutex_unlock(&info->mutex);
                return;
        }

        if (int_status) {
                unsigned int cable_attach;

                cable_attach = int_status & PTN5150_REG_INT_CABLE_ATTACH_MASK;
                if (cable_attach) {
                        ptn5150_check_state(info);
                } else {
                        extcon_set_state_sync(info->edev,
                                        EXTCON_USB_HOST, false);
                        extcon_set_state_sync(info->edev,
                                        EXTCON_USB, false);
                        gpiod_set_value_cansleep(info->vbus_gpiod, 0);

                        ret = usb_role_switch_set_role(info->role_sw,
                                                       USB_ROLE_NONE);
                        if (ret)
                                dev_err(info->dev,
                                        "failed to set none role: %d\n",
                                        ret);
                }
        }

        /* Clear interrupt. Read would clear the register */
        ret = regmap_read(info->regmap, PTN5150_REG_INT_REG_STATUS,
                        &int_status);
        if (ret) {
                dev_err(info->dev,
                        "failed to read INT REG STATUS %d\n", ret);
                mutex_unlock(&info->mutex);
                return;
        }

        mutex_unlock(&info->mutex);
}


static irqreturn_t ptn5150_irq_handler(int irq, void *data)
{
        struct ptn5150_info *info = data;

        schedule_work(&info->irq_work);

        return IRQ_HANDLED;
}

static int ptn5150_init_dev_type(struct ptn5150_info *info)
{
        unsigned int reg_data, vendor_id, version_id;
        int ret;

        ret = regmap_read(info->regmap, PTN5150_REG_DEVICE_ID, &reg_data);
        if (ret) {
                dev_err(info->dev, "failed to read DEVICE_ID %d\n", ret);
                return -EINVAL;
        }

        vendor_id = FIELD_GET(PTN5150_REG_DEVICE_ID_VENDOR, reg_data);
        version_id = FIELD_GET(PTN5150_REG_DEVICE_ID_VERSION, reg_data);
        dev_dbg(info->dev, "Device type: version: 0x%x, vendor: 0x%x\n",
                version_id, vendor_id);

        /* Clear any existing interrupts */
        ret = regmap_read(info->regmap, PTN5150_REG_INT_STATUS, &reg_data);
        if (ret) {
                dev_err(info->dev,
                        "failed to read PTN5150_REG_INT_STATUS %d\n",
                        ret);
                return -EINVAL;
        }

        ret = regmap_read(info->regmap, PTN5150_REG_INT_REG_STATUS, &reg_data);
        if (ret) {
                dev_err(info->dev,
                        "failed to read PTN5150_REG_INT_REG_STATUS %d\n", ret);
                return -EINVAL;
        }

        return 0;
}

static void ptn5150_work_sync_and_put(void *data)
{
        struct ptn5150_info *info = data;

        cancel_work_sync(&info->irq_work);
        usb_role_switch_put(info->role_sw);
}

static int ptn5150_i2c_probe(struct i2c_client *i2c)
{
        struct device *dev = &i2c->dev;
        struct device_node *np = i2c->dev.of_node;
        struct ptn5150_info *info;
        int ret;

        if (!np)
                return -EINVAL;

        info = devm_kzalloc(&i2c->dev, sizeof(*info), GFP_KERNEL);
        if (!info)
                return -ENOMEM;
        i2c_set_clientdata(i2c, info);

        info->dev = &i2c->dev;
        info->i2c = i2c;
        info->vbus_gpiod = devm_gpiod_get(&i2c->dev, "vbus", GPIOD_OUT_LOW);
        if (IS_ERR(info->vbus_gpiod)) {
                ret = PTR_ERR(info->vbus_gpiod);
                if (ret == -ENOENT) {
                        dev_info(dev, "No VBUS GPIO, ignoring VBUS control\n");
                        info->vbus_gpiod = NULL;
                } else {
                        return dev_err_probe(dev, ret, "failed to get VBUS GPIO\n");
                }
        }

        mutex_init(&info->mutex);

        INIT_WORK(&info->irq_work, ptn5150_irq_work);

        info->regmap = devm_regmap_init_i2c(i2c, &ptn5150_regmap_config);
        if (IS_ERR(info->regmap)) {
                return dev_err_probe(info->dev, PTR_ERR(info->regmap),
                                     "failed to allocate register map\n");
        }

        if (i2c->irq > 0) {
                info->irq = i2c->irq;
        } else {
                info->int_gpiod = devm_gpiod_get(&i2c->dev, "int", GPIOD_IN);
                if (IS_ERR(info->int_gpiod)) {
                        return dev_err_probe(dev, PTR_ERR(info->int_gpiod),
                                             "failed to get INT GPIO\n");
                }

                info->irq = gpiod_to_irq(info->int_gpiod);
                if (info->irq < 0) {
                        dev_err(dev, "failed to get INTB IRQ\n");
                        return info->irq;
                }
        }

        ret = devm_request_threaded_irq(dev, info->irq, NULL,
                                        ptn5150_irq_handler,
                                        IRQF_TRIGGER_FALLING |
                                        IRQF_ONESHOT,
                                        i2c->name, info);
        if (ret < 0) {
                dev_err(dev, "failed to request handler for INTB IRQ\n");
                return ret;
        }

        /* Allocate extcon device */
        info->edev = devm_extcon_dev_allocate(info->dev, ptn5150_extcon_cable);
        if (IS_ERR(info->edev)) {
                dev_err(info->dev, "failed to allocate memory for extcon\n");
                return -ENOMEM;
        }

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

        extcon_set_property_capability(info->edev, EXTCON_USB,
                                        EXTCON_PROP_USB_VBUS);
        extcon_set_property_capability(info->edev, EXTCON_USB_HOST,
                                        EXTCON_PROP_USB_VBUS);
        extcon_set_property_capability(info->edev, EXTCON_USB_HOST,
                                        EXTCON_PROP_USB_TYPEC_POLARITY);

        /* Initialize PTN5150 device and print vendor id and version id */
        ret = ptn5150_init_dev_type(info);
        if (ret)
                return -EINVAL;

        info->role_sw = usb_role_switch_get(info->dev);
        if (IS_ERR(info->role_sw))
                return dev_err_probe(info->dev, PTR_ERR(info->role_sw),
                                     "failed to get role switch\n");

        ret = devm_add_action_or_reset(dev, ptn5150_work_sync_and_put, info);
        if (ret)
                return ret;

        /*
         * Update current extcon state if for example OTG connection was there
         * before the probe
         */
        mutex_lock(&info->mutex);
        ptn5150_check_state(info);
        mutex_unlock(&info->mutex);

        return 0;
}

static const struct of_device_id ptn5150_dt_match[] = {
        { .compatible = "nxp,ptn5150" },
        { },
};
MODULE_DEVICE_TABLE(of, ptn5150_dt_match);

static const struct i2c_device_id ptn5150_i2c_id[] = {
        { "ptn5150" },
        { }
};
MODULE_DEVICE_TABLE(i2c, ptn5150_i2c_id);

static struct i2c_driver ptn5150_i2c_driver = {
        .driver         = {
                .name   = "ptn5150",
                .of_match_table = ptn5150_dt_match,
        },
        .probe          = ptn5150_i2c_probe,
        .id_table = ptn5150_i2c_id,
};
module_i2c_driver(ptn5150_i2c_driver);

MODULE_DESCRIPTION("NXP PTN5150 CC logic Extcon driver");
MODULE_AUTHOR("Vijai Kumar K <vijaikumar.kanagarajan@gmail.com>");
MODULE_AUTHOR("Krzysztof Kozlowski <krzk@kernel.org>");
MODULE_LICENSE("GPL v2");