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 | |
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(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 | |
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(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 | |
115 | static 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 | |
124 | static const struct of_device_id max3355_match_table[] = { |
125 | { .compatible = "maxim,max3355" , }, |
126 | { } |
127 | }; |
128 | MODULE_DEVICE_TABLE(of, max3355_match_table); |
129 | |
130 | static 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 | |
139 | module_platform_driver(max3355_driver); |
140 | |
141 | MODULE_AUTHOR("Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>" ); |
142 | MODULE_DESCRIPTION("Maxim MAX3355 extcon driver" ); |
143 | MODULE_LICENSE("GPL v2" ); |
144 | |