| /** |
| * drivers/extcon/extcon-usb-gpio.c - USB GPIO extcon driver |
| * |
| * Copyright (C) 2015 Texas Instruments Incorporated - http://www.ti.com |
| * Author: Roger Quadros <rogerq@ti.com> |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License version 2 as |
| * published by the Free Software Foundation. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| */ |
| |
| #include <linux/extcon.h> |
| #include <linux/gpio.h> |
| #include <linux/gpio/consumer.h> |
| #include <linux/init.h> |
| #include <linux/interrupt.h> |
| #include <linux/irq.h> |
| #include <linux/kernel.h> |
| #include <linux/module.h> |
| #include <linux/of_gpio.h> |
| #include <linux/platform_device.h> |
| #include <linux/slab.h> |
| #include <linux/workqueue.h> |
| #include <linux/acpi.h> |
| #include <linux/pinctrl/consumer.h> |
| |
| #define USB_GPIO_DEBOUNCE_MS 20 /* ms */ |
| |
| struct usb_extcon_info { |
| struct device *dev; |
| struct extcon_dev *edev; |
| |
| struct gpio_desc *id_gpiod; |
| struct gpio_desc *vbus_gpiod; |
| int id_irq; |
| int vbus_irq; |
| |
| unsigned long debounce_jiffies; |
| struct delayed_work wq_detcable; |
| }; |
| |
| static const unsigned int usb_extcon_cable[] = { |
| EXTCON_USB, |
| EXTCON_USB_HOST, |
| EXTCON_NONE, |
| }; |
| |
| /* |
| * "USB" = VBUS and "USB-HOST" = !ID, so we have: |
| * Both "USB" and "USB-HOST" can't be set as active at the |
| * same time so if "USB-HOST" is active (i.e. ID is 0) we keep "USB" inactive |
| * even if VBUS is on. |
| * |
| * State | ID | VBUS |
| * ---------------------------------------- |
| * [1] USB | H | H |
| * [2] none | H | L |
| * [3] USB-HOST | L | H |
| * [4] USB-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_extcon_detect_cable(struct work_struct *work) |
| { |
| int id, vbus; |
| struct usb_extcon_info *info = container_of(to_delayed_work(work), |
| struct usb_extcon_info, |
| wq_detcable); |
| |
| /* check ID and VBUS and update cable state */ |
| id = info->id_gpiod ? |
| gpiod_get_value_cansleep(info->id_gpiod) : 1; |
| vbus = info->vbus_gpiod ? |
| gpiod_get_value_cansleep(info->vbus_gpiod) : id; |
| |
| /* at first we clean states which are no longer active */ |
| if (id) |
| extcon_set_state_sync(info->edev, EXTCON_USB_HOST, false); |
| if (!vbus) |
| extcon_set_state_sync(info->edev, EXTCON_USB, false); |
| |
| if (!id) { |
| extcon_set_state_sync(info->edev, EXTCON_USB_HOST, true); |
| } else { |
| if (vbus) |
| extcon_set_state_sync(info->edev, EXTCON_USB, true); |
| } |
| } |
| |
| static irqreturn_t usb_irq_handler(int irq, void *dev_id) |
| { |
| struct usb_extcon_info *info = dev_id; |
| |
| queue_delayed_work(system_power_efficient_wq, &info->wq_detcable, |
| info->debounce_jiffies); |
| |
| return IRQ_HANDLED; |
| } |
| |
| static int usb_extcon_probe(struct platform_device *pdev) |
| { |
| struct device *dev = &pdev->dev; |
| struct device_node *np = dev->of_node; |
| struct usb_extcon_info *info; |
| int ret; |
| |
| if (!np && !ACPI_HANDLE(dev)) |
| return -EINVAL; |
| |
| info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL); |
| if (!info) |
| return -ENOMEM; |
| |
| info->dev = dev; |
| info->id_gpiod = devm_gpiod_get_optional(&pdev->dev, "id", GPIOD_IN); |
| info->vbus_gpiod = devm_gpiod_get_optional(&pdev->dev, "vbus", |
| GPIOD_IN); |
| |
| if (!info->id_gpiod && !info->vbus_gpiod) { |
| dev_err(dev, "failed to get gpios\n"); |
| return -ENODEV; |
| } |
| |
| if (IS_ERR(info->id_gpiod)) |
| return PTR_ERR(info->id_gpiod); |
| |
| if (IS_ERR(info->vbus_gpiod)) |
| return PTR_ERR(info->vbus_gpiod); |
| |
| info->edev = devm_extcon_dev_allocate(dev, usb_extcon_cable); |
| if (IS_ERR(info->edev)) { |
| dev_err(dev, "failed to allocate extcon device\n"); |
| return -ENOMEM; |
| } |
| |
| ret = devm_extcon_dev_register(dev, info->edev); |
| if (ret < 0) { |
| dev_err(dev, "failed to register extcon device\n"); |
| return ret; |
| } |
| |
| if (info->id_gpiod) |
| ret = gpiod_set_debounce(info->id_gpiod, |
| USB_GPIO_DEBOUNCE_MS * 1000); |
| if (!ret && info->vbus_gpiod) |
| ret = gpiod_set_debounce(info->vbus_gpiod, |
| USB_GPIO_DEBOUNCE_MS * 1000); |
| |
| if (ret < 0) |
| info->debounce_jiffies = msecs_to_jiffies(USB_GPIO_DEBOUNCE_MS); |
| |
| INIT_DELAYED_WORK(&info->wq_detcable, usb_extcon_detect_cable); |
| |
| 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"); |
| return info->id_irq; |
| } |
| |
| ret = devm_request_threaded_irq(dev, info->id_irq, NULL, |
| usb_irq_handler, |
| IRQF_TRIGGER_RISING | |
| IRQF_TRIGGER_FALLING | IRQF_ONESHOT, |
| pdev->name, info); |
| if (ret < 0) { |
| dev_err(dev, "failed to request handler for ID IRQ\n"); |
| return ret; |
| } |
| } |
| |
| 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"); |
| return info->vbus_irq; |
| } |
| |
| ret = devm_request_threaded_irq(dev, info->vbus_irq, NULL, |
| usb_irq_handler, |
| IRQF_TRIGGER_RISING | |
| IRQF_TRIGGER_FALLING | IRQF_ONESHOT, |
| pdev->name, info); |
| if (ret < 0) { |
| dev_err(dev, "failed to request handler for VBUS IRQ\n"); |
| return ret; |
| } |
| } |
| |
| platform_set_drvdata(pdev, info); |
| device_init_wakeup(dev, true); |
| |
| /* Perform initial detection */ |
| usb_extcon_detect_cable(&info->wq_detcable.work); |
| |
| return 0; |
| } |
| |
| static int usb_extcon_remove(struct platform_device *pdev) |
| { |
| struct usb_extcon_info *info = platform_get_drvdata(pdev); |
| |
| cancel_delayed_work_sync(&info->wq_detcable); |
| device_init_wakeup(&pdev->dev, false); |
| |
| return 0; |
| } |
| |
| #ifdef CONFIG_PM_SLEEP |
| static int usb_extcon_suspend(struct device *dev) |
| { |
| struct usb_extcon_info *info = dev_get_drvdata(dev); |
| int ret = 0; |
| |
| if (device_may_wakeup(dev)) { |
| if (info->id_gpiod) { |
| ret = enable_irq_wake(info->id_irq); |
| if (ret) |
| return ret; |
| } |
| if (info->vbus_gpiod) { |
| ret = enable_irq_wake(info->vbus_irq); |
| if (ret) { |
| if (info->id_gpiod) |
| disable_irq_wake(info->id_irq); |
| |
| return ret; |
| } |
| } |
| } |
| |
| /* |
| * We don't want to process any IRQs after this point |
| * as GPIOs used behind I2C subsystem might not be |
| * accessible until resume completes. So disable IRQ. |
| */ |
| if (info->id_gpiod) |
| disable_irq(info->id_irq); |
| if (info->vbus_gpiod) |
| disable_irq(info->vbus_irq); |
| |
| if (!device_may_wakeup(dev)) |
| pinctrl_pm_select_sleep_state(dev); |
| |
| return ret; |
| } |
| |
| static int usb_extcon_resume(struct device *dev) |
| { |
| struct usb_extcon_info *info = dev_get_drvdata(dev); |
| int ret = 0; |
| |
| if (!device_may_wakeup(dev)) |
| pinctrl_pm_select_default_state(dev); |
| |
| if (device_may_wakeup(dev)) { |
| if (info->id_gpiod) { |
| ret = disable_irq_wake(info->id_irq); |
| if (ret) |
| return ret; |
| } |
| if (info->vbus_gpiod) { |
| ret = disable_irq_wake(info->vbus_irq); |
| if (ret) { |
| if (info->id_gpiod) |
| enable_irq_wake(info->id_irq); |
| |
| return ret; |
| } |
| } |
| } |
| |
| if (info->id_gpiod) |
| enable_irq(info->id_irq); |
| if (info->vbus_gpiod) |
| enable_irq(info->vbus_irq); |
| |
| if (!device_may_wakeup(dev)) |
| queue_delayed_work(system_power_efficient_wq, |
| &info->wq_detcable, 0); |
| |
| return ret; |
| } |
| #endif |
| |
| static SIMPLE_DEV_PM_OPS(usb_extcon_pm_ops, |
| usb_extcon_suspend, usb_extcon_resume); |
| |
| static const struct of_device_id usb_extcon_dt_match[] = { |
| { .compatible = "linux,extcon-usb-gpio", }, |
| { /* sentinel */ } |
| }; |
| MODULE_DEVICE_TABLE(of, usb_extcon_dt_match); |
| |
| static const struct platform_device_id usb_extcon_platform_ids[] = { |
| { .name = "extcon-usb-gpio", }, |
| { /* sentinel */ } |
| }; |
| MODULE_DEVICE_TABLE(platform, usb_extcon_platform_ids); |
| |
| static struct platform_driver usb_extcon_driver = { |
| .probe = usb_extcon_probe, |
| .remove = usb_extcon_remove, |
| .driver = { |
| .name = "extcon-usb-gpio", |
| .pm = &usb_extcon_pm_ops, |
| .of_match_table = usb_extcon_dt_match, |
| }, |
| .id_table = usb_extcon_platform_ids, |
| }; |
| |
| module_platform_driver(usb_extcon_driver); |
| |
| MODULE_AUTHOR("Roger Quadros <rogerq@ti.com>"); |
| MODULE_DESCRIPTION("USB GPIO extcon driver"); |
| MODULE_LICENSE("GPL v2"); |