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.h>
11#include <linux/gpio/consumer.h>
12#include <linux/interrupt.h>
13#include <linux/module.h>
14#include <linux/mod_devicetable.h>
15#include <linux/platform_device.h>
16
17struct max3355_data {
18	struct extcon_dev *edev;
19	struct gpio_desc *id_gpiod;
20	struct gpio_desc *shdn_gpiod;
21};
22
23static const unsigned int max3355_cable[] = {
24	EXTCON_USB,
25	EXTCON_USB_HOST,
26	EXTCON_NONE,
27};
28
29static irqreturn_t max3355_id_irq(int irq, void *dev_id)
30{
31	struct max3355_data *data = dev_id;
32	int id = gpiod_get_value_cansleep(data->id_gpiod);
33
34	if (id) {
35		/*
36		 * ID = 1 means USB HOST cable detached.
37		 * As we don't have event for USB peripheral cable attached,
38		 * we simulate USB peripheral attach here.
39		 */
40		extcon_set_state_sync(data->edev, EXTCON_USB_HOST, false);
41		extcon_set_state_sync(data->edev, EXTCON_USB, true);
42	} else {
43		/*
44		 * ID = 0 means USB HOST cable attached.
45		 * As we don't have event for USB peripheral cable detached,
46		 * we simulate USB peripheral detach here.
47		 */
48		extcon_set_state_sync(data->edev, EXTCON_USB, false);
49		extcon_set_state_sync(data->edev, EXTCON_USB_HOST, true);
50	}
51
52	return IRQ_HANDLED;
53}
54
55static int max3355_probe(struct platform_device *pdev)
56{
57	struct max3355_data *data;
58	struct gpio_desc *gpiod;
59	int irq, err;
60
61	data = devm_kzalloc(&pdev->dev, sizeof(struct max3355_data),
62			    GFP_KERNEL);
63	if (!data)
64		return -ENOMEM;
65
66	gpiod = devm_gpiod_get(&pdev->dev, "id", GPIOD_IN);
67	if (IS_ERR(gpiod)) {
68		dev_err(&pdev->dev, "failed to get ID_OUT GPIO\n");
69		return PTR_ERR(gpiod);
70	}
71	data->id_gpiod = gpiod;
72
73	gpiod = devm_gpiod_get(&pdev->dev, "maxim,shdn", GPIOD_OUT_HIGH);
74	if (IS_ERR(gpiod)) {
75		dev_err(&pdev->dev, "failed to get SHDN# GPIO\n");
76		return PTR_ERR(gpiod);
77	}
78	data->shdn_gpiod = gpiod;
79
80	data->edev = devm_extcon_dev_allocate(&pdev->dev, max3355_cable);
81	if (IS_ERR(data->edev)) {
82		dev_err(&pdev->dev, "failed to allocate extcon device\n");
83		return PTR_ERR(data->edev);
84	}
85
86	err = devm_extcon_dev_register(&pdev->dev, data->edev);
87	if (err < 0) {
88		dev_err(&pdev->dev, "failed to register extcon device\n");
89		return err;
90	}
91
92	irq = gpiod_to_irq(data->id_gpiod);
93	if (irq < 0) {
94		dev_err(&pdev->dev, "failed to translate ID_OUT GPIO to IRQ\n");
95		return irq;
96	}
97
98	err = devm_request_threaded_irq(&pdev->dev, irq, NULL, max3355_id_irq,
99					IRQF_ONESHOT | IRQF_NO_SUSPEND |
100					IRQF_TRIGGER_RISING |
101					IRQF_TRIGGER_FALLING,
102					pdev->name, data);
103	if (err < 0) {
104		dev_err(&pdev->dev, "failed to request ID_OUT IRQ\n");
105		return err;
106	}
107
108	platform_set_drvdata(pdev, data);
109
110	/* Perform initial detection */
111	max3355_id_irq(irq, data);
112
113	return 0;
114}
115
116static int max3355_remove(struct platform_device *pdev)
117{
118	struct max3355_data *data = platform_get_drvdata(pdev);
119
120	gpiod_set_value_cansleep(data->shdn_gpiod, 0);
121
122	return 0;
123}
124
125static const struct of_device_id max3355_match_table[] = {
126	{ .compatible = "maxim,max3355", },
127	{ }
128};
129MODULE_DEVICE_TABLE(of, max3355_match_table);
130
131static struct platform_driver max3355_driver = {
132	.probe		= max3355_probe,
133	.remove		= max3355_remove,
134	.driver		= {
135		.name	= "extcon-max3355",
136		.of_match_table = max3355_match_table,
137	},
138};
139
140module_platform_driver(max3355_driver);
141
142MODULE_AUTHOR("Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>");
143MODULE_DESCRIPTION("Maxim MAX3355 extcon driver");
144MODULE_LICENSE("GPL v2");
145