xref: /linux/drivers/extcon/extcon-intel-int3496.c (revision b8d312aa075f33282565467662c4628dae0a2aff)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Intel INT3496 ACPI device extcon driver
4  *
5  * Copyright (c) 2016 Hans de Goede <hdegoede@redhat.com>
6  *
7  * Based on android x86 kernel code which is:
8  *
9  * Copyright (c) 2014, Intel Corporation.
10  * Author: David Cohen <david.a.cohen@linux.intel.com>
11  */
12 
13 #include <linux/acpi.h>
14 #include <linux/extcon-provider.h>
15 #include <linux/gpio/consumer.h>
16 #include <linux/interrupt.h>
17 #include <linux/module.h>
18 #include <linux/platform_device.h>
19 
20 #define INT3496_GPIO_USB_ID	0
21 #define INT3496_GPIO_VBUS_EN	1
22 #define INT3496_GPIO_USB_MUX	2
23 #define DEBOUNCE_TIME		msecs_to_jiffies(50)
24 
25 struct int3496_data {
26 	struct device *dev;
27 	struct extcon_dev *edev;
28 	struct delayed_work work;
29 	struct gpio_desc *gpio_usb_id;
30 	struct gpio_desc *gpio_vbus_en;
31 	struct gpio_desc *gpio_usb_mux;
32 	int usb_id_irq;
33 };
34 
35 static const unsigned int int3496_cable[] = {
36 	EXTCON_USB_HOST,
37 	EXTCON_NONE,
38 };
39 
40 static const struct acpi_gpio_params id_gpios = { INT3496_GPIO_USB_ID, 0, false };
41 static const struct acpi_gpio_params vbus_gpios = { INT3496_GPIO_VBUS_EN, 0, false };
42 static const struct acpi_gpio_params mux_gpios = { INT3496_GPIO_USB_MUX, 0, false };
43 
44 static const struct acpi_gpio_mapping acpi_int3496_default_gpios[] = {
45 	/*
46 	 * Some platforms have a bug in ACPI GPIO description making IRQ
47 	 * GPIO to be output only. Ask the GPIO core to ignore this limit.
48 	 */
49 	{ "id-gpios", &id_gpios, 1, ACPI_GPIO_QUIRK_NO_IO_RESTRICTION },
50 	{ "vbus-gpios", &vbus_gpios, 1 },
51 	{ "mux-gpios", &mux_gpios, 1 },
52 	{ },
53 };
54 
55 static void int3496_do_usb_id(struct work_struct *work)
56 {
57 	struct int3496_data *data =
58 		container_of(work, struct int3496_data, work.work);
59 	int id = gpiod_get_value_cansleep(data->gpio_usb_id);
60 
61 	/* id == 1: PERIPHERAL, id == 0: HOST */
62 	dev_dbg(data->dev, "Connected %s cable\n", id ? "PERIPHERAL" : "HOST");
63 
64 	/*
65 	 * Peripheral: set USB mux to peripheral and disable VBUS
66 	 * Host: set USB mux to host and enable VBUS
67 	 */
68 	if (!IS_ERR(data->gpio_usb_mux))
69 		gpiod_direction_output(data->gpio_usb_mux, id);
70 
71 	if (!IS_ERR(data->gpio_vbus_en))
72 		gpiod_direction_output(data->gpio_vbus_en, !id);
73 
74 	extcon_set_state_sync(data->edev, EXTCON_USB_HOST, !id);
75 }
76 
77 static irqreturn_t int3496_thread_isr(int irq, void *priv)
78 {
79 	struct int3496_data *data = priv;
80 
81 	/* Let the pin settle before processing it */
82 	mod_delayed_work(system_wq, &data->work, DEBOUNCE_TIME);
83 
84 	return IRQ_HANDLED;
85 }
86 
87 static int int3496_probe(struct platform_device *pdev)
88 {
89 	struct device *dev = &pdev->dev;
90 	struct int3496_data *data;
91 	int ret;
92 
93 	ret = devm_acpi_dev_add_driver_gpios(dev, acpi_int3496_default_gpios);
94 	if (ret) {
95 		dev_err(dev, "can't add GPIO ACPI mapping\n");
96 		return ret;
97 	}
98 
99 	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
100 	if (!data)
101 		return -ENOMEM;
102 
103 	data->dev = dev;
104 	INIT_DELAYED_WORK(&data->work, int3496_do_usb_id);
105 
106 	data->gpio_usb_id = devm_gpiod_get(dev, "id", GPIOD_IN);
107 	if (IS_ERR(data->gpio_usb_id)) {
108 		ret = PTR_ERR(data->gpio_usb_id);
109 		dev_err(dev, "can't request USB ID GPIO: %d\n", ret);
110 		return ret;
111 	}
112 
113 	data->usb_id_irq = gpiod_to_irq(data->gpio_usb_id);
114 	if (data->usb_id_irq < 0) {
115 		dev_err(dev, "can't get USB ID IRQ: %d\n", data->usb_id_irq);
116 		return data->usb_id_irq;
117 	}
118 
119 	data->gpio_vbus_en = devm_gpiod_get(dev, "vbus", GPIOD_ASIS);
120 	if (IS_ERR(data->gpio_vbus_en))
121 		dev_info(dev, "can't request VBUS EN GPIO\n");
122 
123 	data->gpio_usb_mux = devm_gpiod_get(dev, "mux", GPIOD_ASIS);
124 	if (IS_ERR(data->gpio_usb_mux))
125 		dev_info(dev, "can't request USB MUX GPIO\n");
126 
127 	/* register extcon device */
128 	data->edev = devm_extcon_dev_allocate(dev, int3496_cable);
129 	if (IS_ERR(data->edev))
130 		return -ENOMEM;
131 
132 	ret = devm_extcon_dev_register(dev, data->edev);
133 	if (ret < 0) {
134 		dev_err(dev, "can't register extcon device: %d\n", ret);
135 		return ret;
136 	}
137 
138 	ret = devm_request_threaded_irq(dev, data->usb_id_irq,
139 					NULL, int3496_thread_isr,
140 					IRQF_SHARED | IRQF_ONESHOT |
141 					IRQF_TRIGGER_RISING |
142 					IRQF_TRIGGER_FALLING,
143 					dev_name(dev), data);
144 	if (ret < 0) {
145 		dev_err(dev, "can't request IRQ for USB ID GPIO: %d\n", ret);
146 		return ret;
147 	}
148 
149 	/* process id-pin so that we start with the right status */
150 	queue_delayed_work(system_wq, &data->work, 0);
151 	flush_delayed_work(&data->work);
152 
153 	platform_set_drvdata(pdev, data);
154 
155 	return 0;
156 }
157 
158 static int int3496_remove(struct platform_device *pdev)
159 {
160 	struct int3496_data *data = platform_get_drvdata(pdev);
161 
162 	devm_free_irq(&pdev->dev, data->usb_id_irq, data);
163 	cancel_delayed_work_sync(&data->work);
164 
165 	return 0;
166 }
167 
168 static const struct acpi_device_id int3496_acpi_match[] = {
169 	{ "INT3496" },
170 	{ }
171 };
172 MODULE_DEVICE_TABLE(acpi, int3496_acpi_match);
173 
174 static struct platform_driver int3496_driver = {
175 	.driver = {
176 		.name = "intel-int3496",
177 		.acpi_match_table = int3496_acpi_match,
178 	},
179 	.probe = int3496_probe,
180 	.remove = int3496_remove,
181 };
182 
183 module_platform_driver(int3496_driver);
184 
185 MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
186 MODULE_DESCRIPTION("Intel INT3496 ACPI device extcon driver");
187 MODULE_LICENSE("GPL v2");
188