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