1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * Maxim Integrated MAX3355 USB OTG chip extcon driver
  4 *
  5 * Copyright (C)  2014-2015 Cogent Embedded, Inc.
  6 * Author: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
  7 */
  8
  9#include <linux/extcon-provider.h>
 10#include <linux/gpio/consumer.h>
 11#include <linux/interrupt.h>
 12#include <linux/module.h>
 13#include <linux/mod_devicetable.h>
 14#include <linux/platform_device.h>
 15
 16struct max3355_data {
 17	struct extcon_dev *edev;
 18	struct gpio_desc *id_gpiod;
 19	struct gpio_desc *shdn_gpiod;
 20};
 21
 22static const unsigned int max3355_cable[] = {
 23	EXTCON_USB,
 24	EXTCON_USB_HOST,
 25	EXTCON_NONE,
 26};
 27
 28static irqreturn_t max3355_id_irq(int irq, void *dev_id)
 29{
 30	struct max3355_data *data = dev_id;
 31	int id = gpiod_get_value_cansleep(data->id_gpiod);
 32
 33	if (id) {
 34		/*
 35		 * ID = 1 means USB HOST cable detached.
 36		 * As we don't have event for USB peripheral cable attached,
 37		 * we simulate USB peripheral attach here.
 38		 */
 39		extcon_set_state_sync(data->edev, EXTCON_USB_HOST, false);
 40		extcon_set_state_sync(data->edev, EXTCON_USB, true);
 41	} else {
 42		/*
 43		 * ID = 0 means USB HOST cable attached.
 44		 * As we don't have event for USB peripheral cable detached,
 45		 * we simulate USB peripheral detach here.
 46		 */
 47		extcon_set_state_sync(data->edev, EXTCON_USB, false);
 48		extcon_set_state_sync(data->edev, EXTCON_USB_HOST, true);
 49	}
 50
 51	return IRQ_HANDLED;
 52}
 53
 54static int max3355_probe(struct platform_device *pdev)
 55{
 56	struct max3355_data *data;
 57	struct gpio_desc *gpiod;
 58	int irq, err;
 59
 60	data = devm_kzalloc(&pdev->dev, sizeof(struct max3355_data),
 61			    GFP_KERNEL);
 62	if (!data)
 63		return -ENOMEM;
 64
 65	gpiod = devm_gpiod_get(&pdev->dev, "id", GPIOD_IN);
 66	if (IS_ERR(gpiod)) {
 67		dev_err(&pdev->dev, "failed to get ID_OUT GPIO\n");
 68		return PTR_ERR(gpiod);
 69	}
 70	data->id_gpiod = gpiod;
 71
 72	gpiod = devm_gpiod_get(&pdev->dev, "maxim,shdn", GPIOD_OUT_HIGH);
 73	if (IS_ERR(gpiod)) {
 74		dev_err(&pdev->dev, "failed to get SHDN# GPIO\n");
 75		return PTR_ERR(gpiod);
 76	}
 77	data->shdn_gpiod = gpiod;
 78
 79	data->edev = devm_extcon_dev_allocate(&pdev->dev, max3355_cable);
 80	if (IS_ERR(data->edev)) {
 81		dev_err(&pdev->dev, "failed to allocate extcon device\n");
 82		return PTR_ERR(data->edev);
 83	}
 84
 85	err = devm_extcon_dev_register(&pdev->dev, data->edev);
 86	if (err < 0) {
 87		dev_err(&pdev->dev, "failed to register extcon device\n");
 88		return err;
 89	}
 90
 91	irq = gpiod_to_irq(data->id_gpiod);
 92	if (irq < 0) {
 93		dev_err(&pdev->dev, "failed to translate ID_OUT GPIO to IRQ\n");
 94		return irq;
 95	}
 96
 97	err = devm_request_threaded_irq(&pdev->dev, irq, NULL, max3355_id_irq,
 98					IRQF_ONESHOT | IRQF_NO_SUSPEND |
 99					IRQF_TRIGGER_RISING |
100					IRQF_TRIGGER_FALLING,
101					pdev->name, data);
102	if (err < 0) {
103		dev_err(&pdev->dev, "failed to request ID_OUT IRQ\n");
104		return err;
105	}
106
107	platform_set_drvdata(pdev, data);
108
109	/* Perform initial detection */
110	max3355_id_irq(irq, data);
111
112	return 0;
113}
114
115static int max3355_remove(struct platform_device *pdev)
116{
117	struct max3355_data *data = platform_get_drvdata(pdev);
118
119	gpiod_set_value_cansleep(data->shdn_gpiod, 0);
120
121	return 0;
122}
123
124static const struct of_device_id max3355_match_table[] = {
125	{ .compatible = "maxim,max3355", },
126	{ }
127};
128MODULE_DEVICE_TABLE(of, max3355_match_table);
129
130static struct platform_driver max3355_driver = {
131	.probe		= max3355_probe,
132	.remove		= max3355_remove,
133	.driver		= {
134		.name	= "extcon-max3355",
135		.of_match_table = max3355_match_table,
136	},
137};
138
139module_platform_driver(max3355_driver);
140
141MODULE_AUTHOR("Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>");
142MODULE_DESCRIPTION("Maxim MAX3355 extcon driver");
143MODULE_LICENSE("GPL v2");