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(desc: 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(edev: data->edev, EXTCON_USB_HOST, state: false);
40 extcon_set_state_sync(edev: data->edev, EXTCON_USB, state: 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(edev: data->edev, EXTCON_USB, state: false);
48 extcon_set_state_sync(edev: data->edev, EXTCON_USB_HOST, state: 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(dev: &pdev->dev, size: sizeof(struct max3355_data),
61 GFP_KERNEL);
62 if (!data)
63 return -ENOMEM;
64
65 gpiod = devm_gpiod_get(dev: &pdev->dev, con_id: "id", flags: GPIOD_IN);
66 if (IS_ERR(ptr: gpiod)) {
67 dev_err(&pdev->dev, "failed to get ID_OUT GPIO\n");
68 return PTR_ERR(ptr: gpiod);
69 }
70 data->id_gpiod = gpiod;
71
72 gpiod = devm_gpiod_get(dev: &pdev->dev, con_id: "maxim,shdn", flags: GPIOD_OUT_HIGH);
73 if (IS_ERR(ptr: gpiod)) {
74 dev_err(&pdev->dev, "failed to get SHDN# GPIO\n");
75 return PTR_ERR(ptr: gpiod);
76 }
77 data->shdn_gpiod = gpiod;
78
79 data->edev = devm_extcon_dev_allocate(dev: &pdev->dev, cable: max3355_cable);
80 if (IS_ERR(ptr: data->edev)) {
81 dev_err(&pdev->dev, "failed to allocate extcon device\n");
82 return PTR_ERR(ptr: data->edev);
83 }
84
85 err = devm_extcon_dev_register(dev: &pdev->dev, edev: 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(desc: 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(dev: &pdev->dev, irq, NULL, thread_fn: max3355_id_irq,
98 IRQF_ONESHOT | IRQF_NO_SUSPEND |
99 IRQF_TRIGGER_RISING |
100 IRQF_TRIGGER_FALLING,
101 devname: pdev->name, dev_id: 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, dev_id: 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(desc: data->shdn_gpiod, value: 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");
144

source code of linux/drivers/extcon/extcon-max3355.c