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
16 struct max3355_data {
17 struct extcon_dev *edev;
18 struct gpio_desc *id_gpiod;
19 struct gpio_desc *shdn_gpiod;
20 };
21
22 static const unsigned int max3355_cable[] = {
23 EXTCON_USB,
24 EXTCON_USB_HOST,
25 EXTCON_NONE,
26 };
27
max3355_id_irq(int irq,void * dev_id)28 static 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
max3355_probe(struct platform_device * pdev)54 static 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
max3355_remove(struct platform_device * pdev)115 static void 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
122 static const struct of_device_id max3355_match_table[] = {
123 { .compatible = "maxim,max3355", },
124 { }
125 };
126 MODULE_DEVICE_TABLE(of, max3355_match_table);
127
128 static struct platform_driver max3355_driver = {
129 .probe = max3355_probe,
130 .remove_new = max3355_remove,
131 .driver = {
132 .name = "extcon-max3355",
133 .of_match_table = max3355_match_table,
134 },
135 };
136
137 module_platform_driver(max3355_driver);
138
139 MODULE_AUTHOR("Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>");
140 MODULE_DESCRIPTION("Maxim MAX3355 extcon driver");
141 MODULE_LICENSE("GPL v2");
142