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
17 struct max3355_data {
18 struct extcon_dev *edev;
19 struct gpio_desc *id_gpiod;
20 struct gpio_desc *shdn_gpiod;
21 };
22
23 static const unsigned int max3355_cable[] = {
24 EXTCON_USB,
25 EXTCON_USB_HOST,
26 EXTCON_NONE,
27 };
28
max3355_id_irq(int irq,void * dev_id)29 static 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
max3355_probe(struct platform_device * pdev)55 static 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
max3355_remove(struct platform_device * pdev)116 static 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
125 static const struct of_device_id max3355_match_table[] = {
126 { .compatible = "maxim,max3355", },
127 { }
128 };
129 MODULE_DEVICE_TABLE(of, max3355_match_table);
130
131 static 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
140 module_platform_driver(max3355_driver);
141
142 MODULE_AUTHOR("Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>");
143 MODULE_DESCRIPTION("Maxim MAX3355 extcon driver");
144 MODULE_LICENSE("GPL v2");
145