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08a0a4f9 SS |
1 | /* |
2 | * Maxim Integrated MAX3355 USB OTG chip extcon driver | |
3 | * | |
4 | * Copyright (C) 2014-2015 Cogent Embedded, Inc. | |
5 | * Author: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com> | |
6 | * | |
7 | * This software is licensed under the terms of the GNU General Public | |
8 | * License version 2, as published by the Free Software Foundation, and | |
9 | * may be copied, distributed, and modified under those terms. | |
10 | */ | |
11 | ||
12 | #include <linux/extcon.h> | |
13 | #include <linux/gpio.h> | |
14 | #include <linux/gpio/consumer.h> | |
15 | #include <linux/interrupt.h> | |
16 | #include <linux/module.h> | |
17 | #include <linux/platform_device.h> | |
18 | ||
19 | struct max3355_data { | |
20 | struct extcon_dev *edev; | |
21 | struct gpio_desc *id_gpiod; | |
22 | struct gpio_desc *shdn_gpiod; | |
23 | }; | |
24 | ||
25 | static const unsigned int max3355_cable[] = { | |
26 | EXTCON_USB, | |
27 | EXTCON_USB_HOST, | |
28 | EXTCON_NONE, | |
29 | }; | |
30 | ||
31 | static irqreturn_t max3355_id_irq(int irq, void *dev_id) | |
32 | { | |
33 | struct max3355_data *data = dev_id; | |
34 | int id = gpiod_get_value_cansleep(data->id_gpiod); | |
35 | ||
36 | if (id) { | |
37 | /* | |
38 | * ID = 1 means USB HOST cable detached. | |
39 | * As we don't have event for USB peripheral cable attached, | |
40 | * we simulate USB peripheral attach here. | |
41 | */ | |
42 | extcon_set_cable_state_(data->edev, EXTCON_USB_HOST, false); | |
43 | extcon_set_cable_state_(data->edev, EXTCON_USB, true); | |
44 | } else { | |
45 | /* | |
46 | * ID = 0 means USB HOST cable attached. | |
47 | * As we don't have event for USB peripheral cable detached, | |
48 | * we simulate USB peripheral detach here. | |
49 | */ | |
50 | extcon_set_cable_state_(data->edev, EXTCON_USB, false); | |
51 | extcon_set_cable_state_(data->edev, EXTCON_USB_HOST, true); | |
52 | } | |
53 | ||
54 | return IRQ_HANDLED; | |
55 | } | |
56 | ||
57 | static int max3355_probe(struct platform_device *pdev) | |
58 | { | |
59 | struct max3355_data *data; | |
60 | struct gpio_desc *gpiod; | |
61 | int irq, err; | |
62 | ||
63 | data = devm_kzalloc(&pdev->dev, sizeof(struct max3355_data), | |
64 | GFP_KERNEL); | |
65 | if (!data) | |
66 | return -ENOMEM; | |
67 | ||
68 | gpiod = devm_gpiod_get(&pdev->dev, "id", GPIOD_IN); | |
69 | if (IS_ERR(gpiod)) { | |
70 | dev_err(&pdev->dev, "failed to get ID_OUT GPIO\n"); | |
71 | return PTR_ERR(gpiod); | |
72 | } | |
73 | data->id_gpiod = gpiod; | |
74 | ||
75 | gpiod = devm_gpiod_get(&pdev->dev, "maxim,shdn", GPIOD_OUT_HIGH); | |
76 | if (IS_ERR(gpiod)) { | |
77 | dev_err(&pdev->dev, "failed to get SHDN# GPIO\n"); | |
78 | return PTR_ERR(gpiod); | |
79 | } | |
80 | data->shdn_gpiod = gpiod; | |
81 | ||
82 | data->edev = devm_extcon_dev_allocate(&pdev->dev, max3355_cable); | |
83 | if (IS_ERR(data->edev)) { | |
84 | dev_err(&pdev->dev, "failed to allocate extcon device\n"); | |
85 | return PTR_ERR(data->edev); | |
86 | } | |
87 | ||
88 | err = devm_extcon_dev_register(&pdev->dev, data->edev); | |
89 | if (err < 0) { | |
90 | dev_err(&pdev->dev, "failed to register extcon device\n"); | |
91 | return err; | |
92 | } | |
93 | ||
94 | irq = gpiod_to_irq(data->id_gpiod); | |
95 | if (irq < 0) { | |
96 | dev_err(&pdev->dev, "failed to translate ID_OUT GPIO to IRQ\n"); | |
97 | return irq; | |
98 | } | |
99 | ||
100 | err = devm_request_threaded_irq(&pdev->dev, irq, NULL, max3355_id_irq, | |
101 | IRQF_ONESHOT | IRQF_NO_SUSPEND | | |
102 | IRQF_TRIGGER_RISING | | |
103 | IRQF_TRIGGER_FALLING, | |
104 | pdev->name, data); | |
105 | if (err < 0) { | |
106 | dev_err(&pdev->dev, "failed to request ID_OUT IRQ\n"); | |
107 | return err; | |
108 | } | |
109 | ||
110 | platform_set_drvdata(pdev, data); | |
111 | ||
112 | /* Perform initial detection */ | |
113 | max3355_id_irq(irq, data); | |
114 | ||
115 | return 0; | |
116 | } | |
117 | ||
118 | static int max3355_remove(struct platform_device *pdev) | |
119 | { | |
120 | struct max3355_data *data = platform_get_drvdata(pdev); | |
121 | ||
122 | gpiod_set_value_cansleep(data->shdn_gpiod, 0); | |
123 | ||
124 | return 0; | |
125 | } | |
126 | ||
127 | static const struct of_device_id max3355_match_table[] = { | |
128 | { .compatible = "maxim,max3355", }, | |
129 | { } | |
130 | }; | |
131 | MODULE_DEVICE_TABLE(of, max3355_match_table); | |
132 | ||
133 | static struct platform_driver max3355_driver = { | |
134 | .probe = max3355_probe, | |
135 | .remove = max3355_remove, | |
136 | .driver = { | |
137 | .name = "extcon-max3355", | |
138 | .of_match_table = max3355_match_table, | |
139 | }, | |
140 | }; | |
141 | ||
142 | module_platform_driver(max3355_driver); | |
143 | ||
144 | MODULE_AUTHOR("Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>"); | |
145 | MODULE_DESCRIPTION("Maxim MAX3355 extcon driver"); | |
146 | MODULE_LICENSE("GPL v2"); |