linux-imx

/*

 * Maxim Integrated MAX3355 USB OTG chip extcon driver

 *

 * Copyright (C)  2014-2015 Cogent Embedded, Inc.

 * Author: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>

 *

 * This software is licensed under the terms of the GNU General Public

 * License version 2, as published by the Free Software Foundation, and

 * may be copied, distributed, and modified under those terms.

 */

​

#include <linux/extcon-provider.h>

#include <linux/gpio.h>

#include <linux/gpio/consumer.h>

#include <linux/interrupt.h>

#include <linux/module.h>

#include <linux/mod_devicetable.h>

#include <linux/platform_device.h>

​

struct max3355_data {

    struct extcon_dev *edev;

    struct gpio_desc *id_gpiod;

    struct gpio_desc *shdn_gpiod;

};

​

static const unsigned int max3355_cable[] = {

    EXTCON_USB,

    EXTCON_USB_HOST,

    EXTCON_NONE,

};

​

static irqreturn_t max3355_id_irq(int irq, void *dev_id)

{

    struct max3355_data *data = dev_id;

    int id = gpiod_get_value_cansleep(data->id_gpiod);

​

    if (id) {

        /*

         * ID = 1 means USB HOST cable detached.

         * As we don't have event for USB peripheral cable attached,

         * we simulate USB peripheral attach here.

         */

        extcon_set_state_sync(data->edev, EXTCON_USB_HOST, false);

        extcon_set_state_sync(data->edev, EXTCON_USB, true);

    } else {

        /*

         * ID = 0 means USB HOST cable attached.

         * As we don't have event for USB peripheral cable detached,

         * we simulate USB peripheral detach here.

         */

        extcon_set_state_sync(data->edev, EXTCON_USB, false);

        extcon_set_state_sync(data->edev, EXTCON_USB_HOST, true);

    }

​

    return IRQ_HANDLED;

}

​

static int max3355_probe(struct platform_device *pdev)

{

    struct max3355_data *data;

    struct gpio_desc *gpiod;

    int irq, err;

​

    data = devm_kzalloc(&pdev->dev, sizeof(struct max3355_data),

                GFP_KERNEL);

    if (!data)

        return -ENOMEM;

​

    gpiod = devm_gpiod_get(&pdev->dev, "id", GPIOD_IN);

    if (IS_ERR(gpiod)) {

        dev_err(&pdev->dev, "failed to get ID_OUT GPIO\n");

        return PTR_ERR(gpiod);

    }

    data->id_gpiod = gpiod;

​

    gpiod = devm_gpiod_get(&pdev->dev, "maxim,shdn", GPIOD_OUT_HIGH);

    if (IS_ERR(gpiod)) {

        dev_err(&pdev->dev, "failed to get SHDN# GPIO\n");

        return PTR_ERR(gpiod);

    }

    data->shdn_gpiod = gpiod;

​

    data->edev = devm_extcon_dev_allocate(&pdev->dev, max3355_cable);

    if (IS_ERR(data->edev)) {

        dev_err(&pdev->dev, "failed to allocate extcon device\n");

        return PTR_ERR(data->edev);

    }

​

    err = devm_extcon_dev_register(&pdev->dev, data->edev);

    if (err < 0) {

        dev_err(&pdev->dev, "failed to register extcon device\n");

        return err;