418 lines
11 KiB
C
418 lines
11 KiB
C
/*
|
|
* 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 = 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.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 = 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;
|
|
}
|
|
|
|
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:
|
|
kfree(gpio_vbus->phy.otg);
|
|
kfree(gpio_vbus);
|
|
return err;
|
|
}
|
|
|
|
static int gpio_vbus_remove(struct platform_device *pdev)
|
|
{
|
|
struct gpio_vbus_data *gpio_vbus = platform_get_drvdata(pdev);
|
|
struct gpio_vbus_mach_info *pdata = dev_get_platdata(&pdev->dev);
|
|
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);
|
|
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
|
|
|
|
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
|
|
},
|
|
.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");
|