aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/extcon/extcon-max3355.c
blob: 0aa410836f4eeec4a25895c9757bea4cb27995f1 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
/*
 * 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/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;
	}

	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");

Privacy Policy