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