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/*
* 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.h>
#include <linux/gpio.h>
#include <linux/gpio/consumer.h>
#include <linux/interrupt.h>
#include <linux/module.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_cable_state_(data->edev, EXTCON_USB_HOST, false);
extcon_set_cable_state_(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_cable_state_(data->edev, EXTCON_USB, false);
extcon_set_cable_state_(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;
}
irq = gpiod_to_irq(data->id_gpiod);
if (irq < 0) {
dev_err(&pdev->dev, "failed to translate ID_OUT GPIO to IRQ\n");
return irq;
}
err = devm_request_threaded_irq(&pdev->dev, irq, NULL, max3355_id_irq,
IRQF_ONESHOT | IRQF_NO_SUSPEND |
IRQF_TRIGGER_RISING |
IRQF_TRIGGER_FALLING,
pdev->name, data);
if (err < 0) {
dev_err(&pdev->dev, "failed to request ID_OUT IRQ\n");
return err;
}
platform_set_drvdata(pdev, data);
/* Perform initial detection */
max3355_id_irq(irq, data);
return 0;
}
static int max3355_remove(struct platform_device *pdev)
{
struct max3355_data *data = platform_get_drvdata(pdev);
gpiod_set_value_cansleep(data->shdn_gpiod, 0);
return 0;
}
static const struct of_device_id max3355_match_table[] = {
{ .compatible = "maxim,max3355", },
{ }
};
MODULE_DEVICE_TABLE(of, max3355_match_table);
static struct platform_driver max3355_driver = {
.probe = max3355_probe,
.remove = max3355_remove,
.driver = {
.name = "extcon-max3355",
.of_match_table = max3355_match_table,
},
};
module_platform_driver(max3355_driver);
MODULE_AUTHOR("Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>");
MODULE_DESCRIPTION("Maxim MAX3355 extcon driver");
MODULE_LICENSE("GPL v2");
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