| /* |
| * gpio-vbus.c - simple GPIO VBUS sensing driver for B peripheral devices |
| * |
| * Copyright (c) 2008 Philipp Zabel <philipp.zabel@gmail.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. |
| */ |
| |
| #include <linux/kernel.h> |
| #include <linux/platform_device.h> |
| #include <linux/gpio.h> |
| #include <linux/module.h> |
| #include <linux/slab.h> |
| #include <linux/interrupt.h> |
| #include <linux/usb.h> |
| #include <linux/workqueue.h> |
| |
| #include <linux/regulator/consumer.h> |
| |
| #include <linux/usb/gadget.h> |
| #include <linux/usb/gpio_vbus.h> |
| #include <linux/usb/otg.h> |
| |
| |
| /* |
| * A simple GPIO VBUS sensing driver for B peripheral only devices |
| * with internal transceivers. It can control a D+ pullup GPIO and |
| * a regulator to limit the current drawn from VBUS. |
| * |
| * Needs to be loaded before the UDC driver that will use it. |
| */ |
| struct gpio_vbus_data { |
| struct usb_phy phy; |
| struct device *dev; |
| struct regulator *vbus_draw; |
| int vbus_draw_enabled; |
| unsigned mA; |
| struct delayed_work work; |
| int vbus; |
| int irq; |
| }; |
| |
| |
| /* |
| * This driver relies on "both edges" triggering. VBUS has 100 msec to |
| * stabilize, so the peripheral controller driver may need to cope with |
| * some bouncing due to current surges (e.g. charging local capacitance) |
| * and contact chatter. |
| * |
| * REVISIT in desperate straits, toggling between rising and falling |
| * edges might be workable. |
| */ |
| #define VBUS_IRQ_FLAGS \ |
| (IRQF_SHARED | IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING) |
| |
| |
| /* interface to regulator framework */ |
| static void set_vbus_draw(struct gpio_vbus_data *gpio_vbus, unsigned mA) |
| { |
| struct regulator *vbus_draw = gpio_vbus->vbus_draw; |
| int enabled; |
| int ret; |
| |
| if (!vbus_draw) |
| return; |
| |
| enabled = gpio_vbus->vbus_draw_enabled; |
| if (mA) { |
| regulator_set_current_limit(vbus_draw, 0, 1000 * mA); |
| if (!enabled) { |
| ret = regulator_enable(vbus_draw); |
| if (ret < 0) |
| return; |
| gpio_vbus->vbus_draw_enabled = 1; |
| } |
| } else { |
| if (enabled) { |
| ret = regulator_disable(vbus_draw); |
| if (ret < 0) |
| return; |
| gpio_vbus->vbus_draw_enabled = 0; |
| } |
| } |
| gpio_vbus->mA = mA; |
| } |
| |
| static int is_vbus_powered(struct gpio_vbus_mach_info *pdata) |
| { |
| int vbus; |
| |
| vbus = gpio_get_value(pdata->gpio_vbus); |
| if (pdata->gpio_vbus_inverted) |
| vbus = !vbus; |
| |
| return vbus; |
| } |
| |
| static void gpio_vbus_work(struct work_struct *work) |
| { |
| struct gpio_vbus_data *gpio_vbus = |
| container_of(work, struct gpio_vbus_data, work.work); |
| struct gpio_vbus_mach_info *pdata = dev_get_platdata(gpio_vbus->dev); |
| int gpio, status, vbus; |
| |
| if (!gpio_vbus->phy.otg->gadget) |
| return; |
| |
| vbus = is_vbus_powered(pdata); |
| if ((vbus ^ gpio_vbus->vbus) == 0) |
| return; |
| gpio_vbus->vbus = vbus; |
| |
| /* Peripheral controllers which manage the pullup themselves won't have |
| * gpio_pullup configured here. If it's configured here, we'll do what |
| * isp1301_omap::b_peripheral() does and enable the pullup here... although |
| * that may complicate usb_gadget_{,dis}connect() support. |
| */ |
| gpio = pdata->gpio_pullup; |
| |
| if (vbus) { |
| status = USB_EVENT_VBUS; |
| gpio_vbus->phy.state = OTG_STATE_B_PERIPHERAL; |
| gpio_vbus->phy.last_event = status; |
| usb_gadget_vbus_connect(gpio_vbus->phy.otg->gadget); |
| |
| /* drawing a "unit load" is *always* OK, except for OTG */ |
| set_vbus_draw(gpio_vbus, 100); |
| |
| /* optionally enable D+ pullup */ |
| if (gpio_is_valid(gpio)) |
| gpio_set_value(gpio, !pdata->gpio_pullup_inverted); |
| |
| atomic_notifier_call_chain(&gpio_vbus->phy.notifier, |
| status, gpio_vbus->phy.otg->gadget); |
| } else { |
| /* optionally disable D+ pullup */ |
| if (gpio_is_valid(gpio)) |
| gpio_set_value(gpio, pdata->gpio_pullup_inverted); |
| |
| set_vbus_draw(gpio_vbus, 0); |
| |
| usb_gadget_vbus_disconnect(gpio_vbus->phy.otg->gadget); |
| status = USB_EVENT_NONE; |
| gpio_vbus->phy.state = OTG_STATE_B_IDLE; |
| gpio_vbus->phy.last_event = status; |
| |
| atomic_notifier_call_chain(&gpio_vbus->phy.notifier, |
| status, gpio_vbus->phy.otg->gadget); |
| } |
| } |
| |
| /* VBUS change IRQ handler */ |
| static irqreturn_t gpio_vbus_irq(int irq, void *data) |
| { |
| struct platform_device *pdev = data; |
| struct gpio_vbus_mach_info *pdata = dev_get_platdata(&pdev->dev); |
| struct gpio_vbus_data *gpio_vbus = platform_get_drvdata(pdev); |
| struct usb_otg *otg = gpio_vbus->phy.otg; |
| |
| dev_dbg(&pdev->dev, "VBUS %s (gadget: %s)\n", |
| is_vbus_powered(pdata) ? "supplied" : "inactive", |
| otg->gadget ? otg->gadget->name : "none"); |
| |
| if (otg->gadget) |
| schedule_delayed_work(&gpio_vbus->work, msecs_to_jiffies(100)); |
| |
| return IRQ_HANDLED; |
| } |
| |
| /* OTG transceiver interface */ |
| |
| /* bind/unbind the peripheral controller */ |
| static int gpio_vbus_set_peripheral(struct usb_otg *otg, |
| struct usb_gadget *gadget) |
| { |
| struct gpio_vbus_data *gpio_vbus; |
| struct gpio_vbus_mach_info *pdata; |
| struct platform_device *pdev; |
| int gpio; |
| |
| gpio_vbus = container_of(otg->phy, struct gpio_vbus_data, phy); |
| pdev = to_platform_device(gpio_vbus->dev); |
| pdata = dev_get_platdata(gpio_vbus->dev); |
| gpio = pdata->gpio_pullup; |
| |
| if (!gadget) { |
| dev_dbg(&pdev->dev, "unregistering gadget '%s'\n", |
| otg->gadget->name); |
| |
| /* optionally disable D+ pullup */ |
| if (gpio_is_valid(gpio)) |
| gpio_set_value(gpio, pdata->gpio_pullup_inverted); |
| |
| set_vbus_draw(gpio_vbus, 0); |
| |
| usb_gadget_vbus_disconnect(otg->gadget); |
| otg->phy->state = OTG_STATE_UNDEFINED; |
| |
| otg->gadget = NULL; |
| return 0; |
| } |
| |
| otg->gadget = gadget; |
| dev_dbg(&pdev->dev, "registered gadget '%s'\n", gadget->name); |
| |
| /* initialize connection state */ |
| gpio_vbus->vbus = 0; /* start with disconnected */ |
| gpio_vbus_irq(gpio_vbus->irq, pdev); |
| return 0; |
| } |
| |
| /* effective for B devices, ignored for A-peripheral */ |
| static int gpio_vbus_set_power(struct usb_phy *phy, unsigned mA) |
| { |
| struct gpio_vbus_data *gpio_vbus; |
| |
| gpio_vbus = container_of(phy, struct gpio_vbus_data, phy); |
| |
| if (phy->state == OTG_STATE_B_PERIPHERAL) |
| set_vbus_draw(gpio_vbus, mA); |
| return 0; |
| } |
| |
| /* for non-OTG B devices: set/clear transceiver suspend mode */ |
| static int gpio_vbus_set_suspend(struct usb_phy *phy, int suspend) |
| { |
| struct gpio_vbus_data *gpio_vbus; |
| |
| gpio_vbus = container_of(phy, struct gpio_vbus_data, phy); |
| |
| /* draw max 0 mA from vbus in suspend mode; or the previously |
| * recorded amount of current if not suspended |
| * |
| * NOTE: high powered configs (mA > 100) may draw up to 2.5 mA |
| * if they're wake-enabled ... we don't handle that yet. |
| */ |
| return gpio_vbus_set_power(phy, suspend ? 0 : gpio_vbus->mA); |
| } |
| |
| /* platform driver interface */ |
| |
| static int gpio_vbus_probe(struct platform_device *pdev) |
| { |
| struct gpio_vbus_mach_info *pdata = dev_get_platdata(&pdev->dev); |
| struct gpio_vbus_data *gpio_vbus; |
| struct resource *res; |
| int err, gpio, irq; |
| unsigned long irqflags; |
| |
| if (!pdata || !gpio_is_valid(pdata->gpio_vbus)) |
| return -EINVAL; |
| gpio = pdata->gpio_vbus; |
| |
| gpio_vbus = devm_kzalloc(&pdev->dev, sizeof(struct gpio_vbus_data), |
| GFP_KERNEL); |
| if (!gpio_vbus) |
| return -ENOMEM; |
| |
| gpio_vbus->phy.otg = devm_kzalloc(&pdev->dev, sizeof(struct usb_otg), |
| GFP_KERNEL); |
| if (!gpio_vbus->phy.otg) |
| return -ENOMEM; |
| |
| platform_set_drvdata(pdev, gpio_vbus); |
| gpio_vbus->dev = &pdev->dev; |
| gpio_vbus->phy.label = "gpio-vbus"; |
| gpio_vbus->phy.dev = gpio_vbus->dev; |
| gpio_vbus->phy.set_power = gpio_vbus_set_power; |
| gpio_vbus->phy.set_suspend = gpio_vbus_set_suspend; |
| gpio_vbus->phy.state = OTG_STATE_UNDEFINED; |
| |
| gpio_vbus->phy.otg->phy = &gpio_vbus->phy; |
| gpio_vbus->phy.otg->set_peripheral = gpio_vbus_set_peripheral; |
| |
| err = devm_gpio_request(&pdev->dev, gpio, "vbus_detect"); |
| if (err) { |
| dev_err(&pdev->dev, "can't request vbus gpio %d, err: %d\n", |
| gpio, err); |
| return err; |
| } |
| gpio_direction_input(gpio); |
| |
| res = platform_get_resource(pdev, IORESOURCE_IRQ, 0); |
| if (res) { |
| irq = res->start; |
| irqflags = (res->flags & IRQF_TRIGGER_MASK) | IRQF_SHARED; |
| } else { |
| irq = gpio_to_irq(gpio); |
| irqflags = VBUS_IRQ_FLAGS; |
| } |
| |
| gpio_vbus->irq = irq; |
| |
| /* if data line pullup is in use, initialize it to "not pulling up" */ |
| gpio = pdata->gpio_pullup; |
| if (gpio_is_valid(gpio)) { |
| err = devm_gpio_request(&pdev->dev, gpio, "udc_pullup"); |
| if (err) { |
| dev_err(&pdev->dev, |
| "can't request pullup gpio %d, err: %d\n", |
| gpio, err); |
| return err; |
| } |
| gpio_direction_output(gpio, pdata->gpio_pullup_inverted); |
| } |
| |
| err = devm_request_irq(&pdev->dev, irq, gpio_vbus_irq, irqflags, |
| "vbus_detect", pdev); |
| if (err) { |
| dev_err(&pdev->dev, "can't request irq %i, err: %d\n", |
| irq, err); |
| return err; |
| } |
| |
| INIT_DELAYED_WORK(&gpio_vbus->work, gpio_vbus_work); |
| |
| gpio_vbus->vbus_draw = devm_regulator_get(&pdev->dev, "vbus_draw"); |
| if (IS_ERR(gpio_vbus->vbus_draw)) { |
| dev_dbg(&pdev->dev, "can't get vbus_draw regulator, err: %ld\n", |
| PTR_ERR(gpio_vbus->vbus_draw)); |
| gpio_vbus->vbus_draw = NULL; |
| } |
| |
| /* only active when a gadget is registered */ |
| err = usb_add_phy(&gpio_vbus->phy, USB_PHY_TYPE_USB2); |
| if (err) { |
| dev_err(&pdev->dev, "can't register transceiver, err: %d\n", |
| err); |
| return err; |
| } |
| |
| device_init_wakeup(&pdev->dev, pdata->wakeup); |
| |
| return 0; |
| } |
| |
| static int gpio_vbus_remove(struct platform_device *pdev) |
| { |
| struct gpio_vbus_data *gpio_vbus = platform_get_drvdata(pdev); |
| |
| device_init_wakeup(&pdev->dev, 0); |
| cancel_delayed_work_sync(&gpio_vbus->work); |
| |
| usb_remove_phy(&gpio_vbus->phy); |
| |
| return 0; |
| } |
| |
| #ifdef CONFIG_PM |
| static int gpio_vbus_pm_suspend(struct device *dev) |
| { |
| struct gpio_vbus_data *gpio_vbus = dev_get_drvdata(dev); |
| |
| if (device_may_wakeup(dev)) |
| enable_irq_wake(gpio_vbus->irq); |
| |
| return 0; |
| } |
| |
| static int gpio_vbus_pm_resume(struct device *dev) |
| { |
| struct gpio_vbus_data *gpio_vbus = dev_get_drvdata(dev); |
| |
| if (device_may_wakeup(dev)) |
| disable_irq_wake(gpio_vbus->irq); |
| |
| return 0; |
| } |
| |
| static const struct dev_pm_ops gpio_vbus_dev_pm_ops = { |
| .suspend = gpio_vbus_pm_suspend, |
| .resume = gpio_vbus_pm_resume, |
| }; |
| #endif |
| |
| MODULE_ALIAS("platform:gpio-vbus"); |
| |
| static struct platform_driver gpio_vbus_driver = { |
| .driver = { |
| .name = "gpio-vbus", |
| #ifdef CONFIG_PM |
| .pm = &gpio_vbus_dev_pm_ops, |
| #endif |
| }, |
| .probe = gpio_vbus_probe, |
| .remove = gpio_vbus_remove, |
| }; |
| |
| module_platform_driver(gpio_vbus_driver); |
| |
| MODULE_DESCRIPTION("simple GPIO controlled OTG transceiver driver"); |
| MODULE_AUTHOR("Philipp Zabel"); |
| MODULE_LICENSE("GPL"); |