linux/drivers/usb/phy/phy-gpio-vbus-usb.c
Greg Kroah-Hartman fb3967b95c USB: phy: Remove redundant license text
Now that the SPDX tag is in all USB files, that identifies the license
in a specific and legally-defined manner.  So the extra GPL text wording
can be removed as it is no longer needed at all.

This is done on a quest to remove the 700+ different ways that files in
the kernel describe the GPL license text.  And there's unneeded stuff
like the address (sometimes incorrect) for the FSF which is never
needed.

No copyright headers or other non-license-description text was removed.

Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Jonathan Hunter <jonathanh@nvidia.com>
Acked-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-07 15:45:01 +01:00

395 lines
10 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* gpio-vbus.c - simple GPIO VBUS sensing driver for B peripheral devices
*
* Copyright (c) 2008 Philipp Zabel <philipp.zabel@gmail.com>
*/
#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.otg->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);
usb_phy_set_event(&gpio_vbus->phy, USB_EVENT_ENUMERATED);
} 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.otg->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);
usb_phy_set_event(&gpio_vbus->phy, USB_EVENT_NONE);
}
}
/* 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->usb_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->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->otg->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.otg->state = OTG_STATE_UNDEFINED;
gpio_vbus->phy.otg->usb_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");