1 files changed, 357 insertions, 0 deletions

diff --git a/drivers/usb/common/usb-conn-gpio.c b/drivers/usb/common/usb-conn-gpio.c
new file mode 100644
index 000000000..3f5180d64
--- /dev/null
+++ b/drivers/usb/common/usb-conn-gpio.c
@@ -0,0 +1,357 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * USB GPIO Based Connection Detection Driver
+ *
+ * Copyright (C) 2019 MediaTek Inc.
+ *
+ * Author: Chunfeng Yun <chunfeng.yun@mediatek.com>
+ *
+ * Some code borrowed from drivers/extcon/extcon-usb-gpio.c
+ */
+
+#include <linux/device.h>
+#include <linux/gpio/consumer.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/pinctrl/consumer.h>
+#include <linux/platform_device.h>
+#include <linux/power_supply.h>
+#include <linux/regulator/consumer.h>
+#include <linux/usb/role.h>
+
+#define USB_GPIO_DEB_MS		20	/* ms */
+#define USB_GPIO_DEB_US		((USB_GPIO_DEB_MS) * 1000)	/* us */
+
+#define USB_CONN_IRQF	\
+	(IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING | IRQF_ONESHOT)
+
+struct usb_conn_info {
+	struct device *dev;
+	struct usb_role_switch *role_sw;
+	enum usb_role last_role;
+	struct regulator *vbus;
+	struct delayed_work dw_det;
+	unsigned long debounce_jiffies;
+
+	struct gpio_desc *id_gpiod;
+	struct gpio_desc *vbus_gpiod;
+	int id_irq;
+	int vbus_irq;
+
+	struct power_supply_desc desc;
+	struct power_supply *charger;
+	bool initial_detection;
+};
+
+/*
+ * "DEVICE" = VBUS and "HOST" = !ID, so we have:
+ * Both "DEVICE" and "HOST" can't be set as active at the same time
+ * so if "HOST" is active (i.e. ID is 0)  we keep "DEVICE" inactive
+ * even if VBUS is on.
+ *
+ *  Role          |   ID  |  VBUS
+ * ------------------------------------
+ *  [1] DEVICE    |   H   |   H
+ *  [2] NONE      |   H   |   L
+ *  [3] HOST      |   L   |   H
+ *  [4] HOST      |   L   |   L
+ *
+ * In case we have only one of these signals:
+ * - VBUS only - we want to distinguish between [1] and [2], so ID is always 1
+ * - ID only - we want to distinguish between [1] and [4], so VBUS = ID
+ */
+static void usb_conn_detect_cable(struct work_struct *work)
+{
+	struct usb_conn_info *info;
+	enum usb_role role;
+	int id, vbus, ret;
+
+	info = container_of(to_delayed_work(work),
+			    struct usb_conn_info, dw_det);
+
+	/* check ID and VBUS */
+	id = info->id_gpiod ?
+		gpiod_get_value_cansleep(info->id_gpiod) : 1;
+	vbus = info->vbus_gpiod ?
+		gpiod_get_value_cansleep(info->vbus_gpiod) : id;
+
+	if (!id)
+		role = USB_ROLE_HOST;
+	else if (vbus)
+		role = USB_ROLE_DEVICE;
+	else
+		role = USB_ROLE_NONE;
+
+	dev_dbg(info->dev, "role %s -> %s, gpios: id %d, vbus %d\n",
+		usb_role_string(info->last_role), usb_role_string(role), id, vbus);
+
+	if (!info->initial_detection && info->last_role == role) {
+		dev_warn(info->dev, "repeated role: %s\n", usb_role_string(role));
+		return;
+	}
+
+	info->initial_detection = false;
+
+	if (info->last_role == USB_ROLE_HOST && info->vbus)
+		regulator_disable(info->vbus);
+
+	ret = usb_role_switch_set_role(info->role_sw, role);
+	if (ret)
+		dev_err(info->dev, "failed to set role: %d\n", ret);
+
+	if (role == USB_ROLE_HOST && info->vbus) {
+		ret = regulator_enable(info->vbus);
+		if (ret)
+			dev_err(info->dev, "enable vbus regulator failed\n");
+	}
+
+	info->last_role = role;
+
+	if (info->vbus)
+		dev_dbg(info->dev, "vbus regulator is %s\n",
+			regulator_is_enabled(info->vbus) ? "enabled" : "disabled");
+
+	power_supply_changed(info->charger);
+}
+
+static void usb_conn_queue_dwork(struct usb_conn_info *info,
+				 unsigned long delay)
+{
+	queue_delayed_work(system_power_efficient_wq, &info->dw_det, delay);
+}
+
+static irqreturn_t usb_conn_isr(int irq, void *dev_id)
+{
+	struct usb_conn_info *info = dev_id;
+
+	usb_conn_queue_dwork(info, info->debounce_jiffies);
+
+	return IRQ_HANDLED;
+}
+
+static enum power_supply_property usb_charger_properties[] = {
+	POWER_SUPPLY_PROP_ONLINE,
+};
+
+static int usb_charger_get_property(struct power_supply *psy,
+				    enum power_supply_property psp,
+				    union power_supply_propval *val)
+{
+	struct usb_conn_info *info = power_supply_get_drvdata(psy);
+
+	switch (psp) {
+	case POWER_SUPPLY_PROP_ONLINE:
+		val->intval = info->last_role == USB_ROLE_DEVICE;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int usb_conn_psy_register(struct usb_conn_info *info)
+{
+	struct device *dev = info->dev;
+	struct power_supply_desc *desc = &info->desc;
+	struct power_supply_config cfg = {
+		.of_node = dev->of_node,
+	};
+
+	desc->name = "usb-charger";
+	desc->properties = usb_charger_properties;
+	desc->num_properties = ARRAY_SIZE(usb_charger_properties);
+	desc->get_property = usb_charger_get_property;
+	desc->type = POWER_SUPPLY_TYPE_USB;
+	cfg.drv_data = info;
+
+	info->charger = devm_power_supply_register(dev, desc, &cfg);
+	if (IS_ERR(info->charger))
+		dev_err(dev, "Unable to register charger\n");
+
+	return PTR_ERR_OR_ZERO(info->charger);
+}
+
+static int usb_conn_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct usb_conn_info *info;
+	int ret = 0;
+
+	info = devm_kzalloc(dev, sizeof(*info), GFP_KERNEL);
+	if (!info)
+		return -ENOMEM;
+
+	info->dev = dev;
+	info->id_gpiod = devm_gpiod_get_optional(dev, "id", GPIOD_IN);
+	if (IS_ERR(info->id_gpiod))
+		return PTR_ERR(info->id_gpiod);
+
+	info->vbus_gpiod = devm_gpiod_get_optional(dev, "vbus", GPIOD_IN);
+	if (IS_ERR(info->vbus_gpiod))
+		return PTR_ERR(info->vbus_gpiod);
+
+	if (!info->id_gpiod && !info->vbus_gpiod) {
+		dev_err(dev, "failed to get gpios\n");
+		return -ENODEV;
+	}
+
+	if (info->id_gpiod)
+		ret = gpiod_set_debounce(info->id_gpiod, USB_GPIO_DEB_US);
+	if (!ret && info->vbus_gpiod)
+		ret = gpiod_set_debounce(info->vbus_gpiod, USB_GPIO_DEB_US);
+	if (ret < 0)
+		info->debounce_jiffies = msecs_to_jiffies(USB_GPIO_DEB_MS);
+
+	INIT_DELAYED_WORK(&info->dw_det, usb_conn_detect_cable);
+
+	info->vbus = devm_regulator_get_optional(dev, "vbus");
+	if (PTR_ERR(info->vbus) == -ENODEV)
+		info->vbus = NULL;
+
+	if (IS_ERR(info->vbus))
+		return dev_err_probe(dev, PTR_ERR(info->vbus), "failed to get vbus\n");
+
+	info->role_sw = usb_role_switch_get(dev);
+	if (IS_ERR(info->role_sw))
+		return dev_err_probe(dev, PTR_ERR(info->role_sw),
+				     "failed to get role switch\n");
+
+	ret = usb_conn_psy_register(info);
+	if (ret)
+		goto put_role_sw;
+
+	if (info->id_gpiod) {
+		info->id_irq = gpiod_to_irq(info->id_gpiod);
+		if (info->id_irq < 0) {
+			dev_err(dev, "failed to get ID IRQ\n");
+			ret = info->id_irq;
+			goto put_role_sw;
+		}
+
+		ret = devm_request_threaded_irq(dev, info->id_irq, NULL,
+						usb_conn_isr, USB_CONN_IRQF,
+						pdev->name, info);
+		if (ret < 0) {
+			dev_err(dev, "failed to request ID IRQ\n");
+			goto put_role_sw;
+		}
+	}
+
+	if (info->vbus_gpiod) {
+		info->vbus_irq = gpiod_to_irq(info->vbus_gpiod);
+		if (info->vbus_irq < 0) {
+			dev_err(dev, "failed to get VBUS IRQ\n");
+			ret = info->vbus_irq;
+			goto put_role_sw;
+		}
+
+		ret = devm_request_threaded_irq(dev, info->vbus_irq, NULL,
+						usb_conn_isr, USB_CONN_IRQF,
+						pdev->name, info);
+		if (ret < 0) {
+			dev_err(dev, "failed to request VBUS IRQ\n");
+			goto put_role_sw;
+		}
+	}
+
+	platform_set_drvdata(pdev, info);
+	device_set_wakeup_capable(&pdev->dev, true);
+
+	/* Perform initial detection */
+	info->initial_detection = true;
+	usb_conn_queue_dwork(info, 0);
+
+	return 0;
+
+put_role_sw:
+	usb_role_switch_put(info->role_sw);
+	return ret;
+}
+
+static int usb_conn_remove(struct platform_device *pdev)
+{
+	struct usb_conn_info *info = platform_get_drvdata(pdev);
+
+	cancel_delayed_work_sync(&info->dw_det);
+
+	if (info->last_role == USB_ROLE_HOST && info->vbus)
+		regulator_disable(info->vbus);
+
+	usb_role_switch_put(info->role_sw);
+
+	return 0;
+}
+
+static int __maybe_unused usb_conn_suspend(struct device *dev)
+{
+	struct usb_conn_info *info = dev_get_drvdata(dev);
+
+	if (device_may_wakeup(dev)) {
+		if (info->id_gpiod)
+			enable_irq_wake(info->id_irq);
+		if (info->vbus_gpiod)
+			enable_irq_wake(info->vbus_irq);
+		return 0;
+	}
+
+	if (info->id_gpiod)
+		disable_irq(info->id_irq);
+	if (info->vbus_gpiod)
+		disable_irq(info->vbus_irq);
+
+	pinctrl_pm_select_sleep_state(dev);
+
+	return 0;
+}
+
+static int __maybe_unused usb_conn_resume(struct device *dev)
+{
+	struct usb_conn_info *info = dev_get_drvdata(dev);
+
+	if (device_may_wakeup(dev)) {
+		if (info->id_gpiod)
+			disable_irq_wake(info->id_irq);
+		if (info->vbus_gpiod)
+			disable_irq_wake(info->vbus_irq);
+		return 0;
+	}
+
+	pinctrl_pm_select_default_state(dev);
+
+	if (info->id_gpiod)
+		enable_irq(info->id_irq);
+	if (info->vbus_gpiod)
+		enable_irq(info->vbus_irq);
+
+	usb_conn_queue_dwork(info, 0);
+
+	return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(usb_conn_pm_ops,
+			 usb_conn_suspend, usb_conn_resume);
+
+static const struct of_device_id usb_conn_dt_match[] = {
+	{ .compatible = "gpio-usb-b-connector", },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, usb_conn_dt_match);
+
+static struct platform_driver usb_conn_driver = {
+	.probe		= usb_conn_probe,
+	.remove		= usb_conn_remove,
+	.driver		= {
+		.name	= "usb-conn-gpio",
+		.pm	= &usb_conn_pm_ops,
+		.of_match_table = usb_conn_dt_match,
+	},
+};
+
+module_platform_driver(usb_conn_driver);
+
+MODULE_AUTHOR("Chunfeng Yun <chunfeng.yun@mediatek.com>");
+MODULE_DESCRIPTION("USB GPIO based connection detection driver");
+MODULE_LICENSE("GPL v2");