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
 25struct 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
 35static const unsigned int int3496_cable[] = {
 36	EXTCON_USB_HOST,
 37	EXTCON_NONE,
 38};
 39
 40static const struct acpi_gpio_params id_gpios = { INT3496_GPIO_USB_ID, 0, false };
 41static const struct acpi_gpio_params vbus_gpios = { INT3496_GPIO_VBUS_EN, 0, false };
 42static const struct acpi_gpio_params mux_gpios = { INT3496_GPIO_USB_MUX, 0, false };
 43
 44static 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
 55static 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
 77static 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
 87static 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
158static 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
168static const struct acpi_device_id int3496_acpi_match[] = {
169	{ "INT3496" },
170	{ }
171};
172MODULE_DEVICE_TABLE(acpi, int3496_acpi_match);
173
174static 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
183module_platform_driver(int3496_driver);
184
185MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
186MODULE_DESCRIPTION("Intel INT3496 ACPI device extcon driver");
187MODULE_LICENSE("GPL v2");