diff options
Diffstat (limited to 'drivers/extcon/extcon-usb-gpio.c')
| -rw-r--r-- | drivers/extcon/extcon-usb-gpio.c | 313 |
1 files changed, 313 insertions, 0 deletions
diff --git a/drivers/extcon/extcon-usb-gpio.c b/drivers/extcon/extcon-usb-gpio.c new file mode 100644 index 000000000..f06be6d4e --- /dev/null +++ b/drivers/extcon/extcon-usb-gpio.c @@ -0,0 +1,313 @@ +// SPDX-License-Identifier: GPL-2.0-only +/** + * drivers/extcon/extcon-usb-gpio.c - USB GPIO extcon driver + * + * Copyright (C) 2015 Texas Instruments Incorporated - https://www.ti.com + * Author: Roger Quadros <rogerq@ti.com> + */ + +#include <linux/extcon-provider.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/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vbus_gpiod) : id; + + /* at first we clean states which are no longer active */ + if (id) + extcon_set_state_sync(info-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) + 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_set_wakeup_capable(&pdev->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); + + 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"); |