| // 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; |
| }; |
| |
| /* |
| * "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->last_role == role) { |
| dev_warn(info->dev, "repeated role: %s\n", usb_role_string(role)); |
| return; |
| } |
| |
| 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)) { |
| ret = PTR_ERR(info->vbus); |
| return dev_err_probe(dev, ret, "failed to get vbus :%d\n", ret); |
| } |
| |
| 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 */ |
| 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"); |