1 files changed, 421 insertions, 0 deletions

diff --git a/drivers/usb/phy/phy-gpio-vbus-usb.c b/drivers/usb/phy/phy-gpio-vbus-usb.c
new file mode 100644
index 000000000000..4c76074e518d
--- /dev/null
+++ b/drivers/usb/phy/phy-gpio-vbus-usb.c
@@ -0,0 +1,421 @@
+/*
+ * 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 = gpio_vbus->dev->platform_data;
+        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 = pdev->dev.platform_data;
+        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 = gpio_vbus->dev->platform_data;
+        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 __init gpio_vbus_probe(struct platform_device *pdev)
+{
+        struct gpio_vbus_mach_info *pdata = pdev->dev.platform_data;
+        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 = kzalloc(sizeof(struct gpio_vbus_data), GFP_KERNEL);
+        if (!gpio_vbus)
+                return -ENOMEM;
+
+        gpio_vbus->phy.otg = kzalloc(sizeof(struct usb_otg), GFP_KERNEL);
+        if (!gpio_vbus->phy.otg) {
+                kfree(gpio_vbus);
+                return -ENOMEM;
+        }
+
+        platform_set_drvdata(pdev, gpio_vbus);
+        gpio_vbus->dev = &pdev->dev;
+        gpio_vbus->phy.label = "gpio-vbus";
+        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 = gpio_request(gpio, "vbus_detect");
+        if (err) {
+                dev_err(&pdev->dev, "can't request vbus gpio %d, err: %d\n",
+                        gpio, err);
+                goto err_gpio;
+        }
+        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 = gpio_request(gpio, "udc_pullup");
+                if (err) {
+                        dev_err(&pdev->dev,
+                                "can't request pullup gpio %d, err: %d\n",
+                                gpio, err);
+                        gpio_free(pdata->gpio_vbus);
+                        goto err_gpio;
+                }
+                gpio_direction_output(gpio, pdata->gpio_pullup_inverted);
+        }
+
+        err = request_irq(irq, gpio_vbus_irq, irqflags, "vbus_detect", pdev);
+        if (err) {
+                dev_err(&pdev->dev, "can't request irq %i, err: %d\n",
+                        irq, err);
+                goto err_irq;
+        }
+
+        ATOMIC_INIT_NOTIFIER_HEAD(&gpio_vbus->phy.notifier);
+
+        INIT_DELAYED_WORK(&gpio_vbus->work, gpio_vbus_work);
+
+        gpio_vbus->vbus_draw = 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);
+                goto err_otg;
+        }
+
+        device_init_wakeup(&pdev->dev, pdata->wakeup);
+
+        return 0;
+err_otg:
+        regulator_put(gpio_vbus->vbus_draw);
+        free_irq(irq, pdev);
+err_irq:
+        if (gpio_is_valid(pdata->gpio_pullup))
+                gpio_free(pdata->gpio_pullup);
+        gpio_free(pdata->gpio_vbus);
+err_gpio:
+        platform_set_drvdata(pdev, NULL);
+        kfree(gpio_vbus->phy.otg);
+        kfree(gpio_vbus);
+        return err;
+}
+
+static int __exit gpio_vbus_remove(struct platform_device *pdev)
+{
+        struct gpio_vbus_data *gpio_vbus = platform_get_drvdata(pdev);
+        struct gpio_vbus_mach_info *pdata = pdev->dev.platform_data;
+        int gpio = pdata->gpio_vbus;
+
+        device_init_wakeup(&pdev->dev, 0);
+        cancel_delayed_work_sync(&gpio_vbus->work);
+        regulator_put(gpio_vbus->vbus_draw);
+
+        usb_remove_phy(&gpio_vbus->phy);
+
+        free_irq(gpio_vbus->irq, pdev);
+        if (gpio_is_valid(pdata->gpio_pullup))
+                gpio_free(pdata->gpio_pullup);
+        gpio_free(gpio);
+        platform_set_drvdata(pdev, NULL);
+        kfree(gpio_vbus->phy.otg);
+        kfree(gpio_vbus);
+
+        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
+
+/* NOTE:  the gpio-vbus device may *NOT* be hotplugged */
+
+MODULE_ALIAS("platform:gpio-vbus");
+
+static struct platform_driver gpio_vbus_driver = {
+        .driver = {
+                .name  = "gpio-vbus",
+                .owner = THIS_MODULE,
+#ifdef CONFIG_PM
+                .pm = &gpio_vbus_dev_pm_ops,
+#endif
+        },
+        .remove  = __exit_p(gpio_vbus_remove),
+};
+
+module_platform_driver_probe(gpio_vbus_driver, gpio_vbus_probe);
+
+MODULE_DESCRIPTION("simple GPIO controlled OTG transceiver driver");
+MODULE_AUTHOR("Philipp Zabel");
+MODULE_LICENSE("GPL");