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#include <linux/regulator/consumer.h>
 21
 22#define INT3496_GPIO_USB_ID	0
 23#define INT3496_GPIO_VBUS_EN	1
 24#define INT3496_GPIO_USB_MUX	2
 25#define DEBOUNCE_TIME		msecs_to_jiffies(50)
 26
 27struct int3496_data {
 28	struct device *dev;
 29	struct extcon_dev *edev;
 30	struct delayed_work work;
 31	struct gpio_desc *gpio_usb_id;
 32	struct gpio_desc *gpio_vbus_en;
 33	struct gpio_desc *gpio_usb_mux;
 34	struct regulator *vbus_boost;
 35	int usb_id_irq;
 36	bool vbus_boost_enabled;
 37};
 38
 39static const unsigned int int3496_cable[] = {
 40	EXTCON_USB_HOST,
 41	EXTCON_NONE,
 42};
 43
 44static const struct acpi_gpio_params id_gpios = { INT3496_GPIO_USB_ID, 0, false };
 45static const struct acpi_gpio_params vbus_gpios = { INT3496_GPIO_VBUS_EN, 0, false };
 46static const struct acpi_gpio_params mux_gpios = { INT3496_GPIO_USB_MUX, 0, false };
 47
 48static const struct acpi_gpio_mapping acpi_int3496_default_gpios[] = {
 49	/*
 50	 * Some platforms have a bug in ACPI GPIO description making IRQ
 51	 * GPIO to be output only. Ask the GPIO core to ignore this limit.
 52	 */
 53	{ "id-gpios", &id_gpios, 1, ACPI_GPIO_QUIRK_NO_IO_RESTRICTION },
 54	{ "vbus-gpios", &vbus_gpios, 1 },
 55	{ "mux-gpios", &mux_gpios, 1 },
 56	{ },
 57};
 58
 59static void int3496_set_vbus_boost(struct int3496_data *data, bool enable)
 60{
 61	int ret;
 62
 63	if (IS_ERR_OR_NULL(data->vbus_boost))
 64		return;
 65
 66	if (data->vbus_boost_enabled == enable)
 67		return;
 68
 69	if (enable)
 70		ret = regulator_enable(data->vbus_boost);
 71	else
 72		ret = regulator_disable(data->vbus_boost);
 73
 74	if (ret == 0)
 75		data->vbus_boost_enabled = enable;
 76	else
 77		dev_err(data->dev, "Error updating Vbus boost regulator: %d\n", ret);
 78}
 79
 80static void int3496_do_usb_id(struct work_struct *work)
 81{
 82	struct int3496_data *data =
 83		container_of(work, struct int3496_data, work.work);
 84	int id = gpiod_get_value_cansleep(data->gpio_usb_id);
 85
 86	/* id == 1: PERIPHERAL, id == 0: HOST */
 87	dev_dbg(data->dev, "Connected %s cable\n", id ? "PERIPHERAL" : "HOST");
 88
 89	/*
 90	 * Peripheral: set USB mux to peripheral and disable VBUS
 91	 * Host: set USB mux to host and enable VBUS
 92	 */
 93	if (!IS_ERR(data->gpio_usb_mux))
 94		gpiod_direction_output(data->gpio_usb_mux, id);
 95
 96	if (!IS_ERR(data->gpio_vbus_en))
 97		gpiod_direction_output(data->gpio_vbus_en, !id);
 98	else
 99		int3496_set_vbus_boost(data, !id);
100
101	extcon_set_state_sync(data->edev, EXTCON_USB_HOST, !id);
102}
103
104static irqreturn_t int3496_thread_isr(int irq, void *priv)
105{
106	struct int3496_data *data = priv;
107
108	/* Let the pin settle before processing it */
109	mod_delayed_work(system_wq, &data->work, DEBOUNCE_TIME);
110
111	return IRQ_HANDLED;
112}
113
114static int int3496_probe(struct platform_device *pdev)
115{
116	struct device *dev = &pdev->dev;
117	struct int3496_data *data;
118	int ret;
119
120	if (has_acpi_companion(dev)) {
121		ret = devm_acpi_dev_add_driver_gpios(dev, acpi_int3496_default_gpios);
122		if (ret) {
123			dev_err(dev, "can't add GPIO ACPI mapping\n");
124			return ret;
125		}
126	}
127
128	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
129	if (!data)
130		return -ENOMEM;
131
132	data->dev = dev;
133	ret = devm_delayed_work_autocancel(dev, &data->work, int3496_do_usb_id);
134	if (ret)
135		return ret;
136
137	data->gpio_usb_id =
138		devm_gpiod_get(dev, "id", GPIOD_IN | GPIOD_FLAGS_BIT_NONEXCLUSIVE);
139	if (IS_ERR(data->gpio_usb_id)) {
140		ret = PTR_ERR(data->gpio_usb_id);
141		dev_err(dev, "can't request USB ID GPIO: %d\n", ret);
142		return ret;
143	}
144
145	data->usb_id_irq = gpiod_to_irq(data->gpio_usb_id);
146	if (data->usb_id_irq < 0) {
147		dev_err(dev, "can't get USB ID IRQ: %d\n", data->usb_id_irq);
148		return data->usb_id_irq;
149	}
150
151	data->gpio_vbus_en = devm_gpiod_get(dev, "vbus", GPIOD_ASIS);
152	if (IS_ERR(data->gpio_vbus_en)) {
153		dev_dbg(dev, "can't request VBUS EN GPIO\n");
154		data->vbus_boost = devm_regulator_get_optional(dev, "vbus");
155	}
156
157	data->gpio_usb_mux = devm_gpiod_get(dev, "mux", GPIOD_ASIS);
158	if (IS_ERR(data->gpio_usb_mux))
159		dev_dbg(dev, "can't request USB MUX GPIO\n");
160
161	/* register extcon device */
162	data->edev = devm_extcon_dev_allocate(dev, int3496_cable);
163	if (IS_ERR(data->edev))
164		return -ENOMEM;
165
166	ret = devm_extcon_dev_register(dev, data->edev);
167	if (ret < 0) {
168		dev_err(dev, "can't register extcon device: %d\n", ret);
169		return ret;
170	}
171
172	ret = devm_request_threaded_irq(dev, data->usb_id_irq,
173					NULL, int3496_thread_isr,
174					IRQF_SHARED | IRQF_ONESHOT |
175					IRQF_TRIGGER_RISING |
176					IRQF_TRIGGER_FALLING,
177					dev_name(dev), data);
178	if (ret < 0) {
179		dev_err(dev, "can't request IRQ for USB ID GPIO: %d\n", ret);
180		return ret;
181	}
182
183	/* process id-pin so that we start with the right status */
184	queue_delayed_work(system_wq, &data->work, 0);
185	flush_delayed_work(&data->work);
186
187	platform_set_drvdata(pdev, data);
188
189	return 0;
190}
191
192static const struct acpi_device_id int3496_acpi_match[] = {
193	{ "INT3496" },
194	{ }
195};
196MODULE_DEVICE_TABLE(acpi, int3496_acpi_match);
197
198static const struct platform_device_id int3496_ids[] = {
199	{ .name = "intel-int3496" },
200	{},
201};
202MODULE_DEVICE_TABLE(platform, int3496_ids);
203
204static struct platform_driver int3496_driver = {
205	.driver = {
206		.name = "intel-int3496",
207		.acpi_match_table = int3496_acpi_match,
208	},
209	.probe = int3496_probe,
210	.id_table = int3496_ids,
211};
212
213module_platform_driver(int3496_driver);
214
215MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
216MODULE_DESCRIPTION("Intel INT3496 ACPI device extcon driver");
217MODULE_LICENSE("GPL v2");