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