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
 26struct 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
 36static const unsigned int int3496_cable[] = {
 37	EXTCON_USB_HOST,
 38	EXTCON_NONE,
 39};
 40
 41static const struct acpi_gpio_params id_gpios = { INT3496_GPIO_USB_ID, 0, false };
 42static const struct acpi_gpio_params vbus_gpios = { INT3496_GPIO_VBUS_EN, 0, false };
 43static const struct acpi_gpio_params mux_gpios = { INT3496_GPIO_USB_MUX, 0, false };
 44
 45static 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
 56static 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
 78static 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
 88static 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
161static const struct acpi_device_id int3496_acpi_match[] = {
162	{ "INT3496" },
163	{ }
164};
165MODULE_DEVICE_TABLE(acpi, int3496_acpi_match);
166
167static 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
175module_platform_driver(int3496_driver);
176
177MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
178MODULE_DESCRIPTION("Intel INT3496 ACPI device extcon driver");
179MODULE_LICENSE("GPL v2");