linux/drivers/usb/phy/phy-gpio-vbus-usb.c
Linus Torvalds e6b5be2be4 Driver core patches for 3.19-rc1
Here's the set of driver core patches for 3.19-rc1.
 
 They are dominated by the removal of the .owner field in platform
 drivers.  They touch a lot of files, but they are "simple" changes, just
 removing a line in a structure.
 
 Other than that, a few minor driver core and debugfs changes.  There are
 some ath9k patches coming in through this tree that have been acked by
 the wireless maintainers as they relied on the debugfs changes.
 
 Everything has been in linux-next for a while.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core update from Greg KH:
 "Here's the set of driver core patches for 3.19-rc1.

  They are dominated by the removal of the .owner field in platform
  drivers.  They touch a lot of files, but they are "simple" changes,
  just removing a line in a structure.

  Other than that, a few minor driver core and debugfs changes.  There
  are some ath9k patches coming in through this tree that have been
  acked by the wireless maintainers as they relied on the debugfs
  changes.

  Everything has been in linux-next for a while"

* tag 'driver-core-3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (324 commits)
  Revert "ath: ath9k: use debugfs_create_devm_seqfile() helper for seq_file entries"
  fs: debugfs: add forward declaration for struct device type
  firmware class: Deletion of an unnecessary check before the function call "vunmap"
  firmware loader: fix hung task warning dump
  devcoredump: provide a one-way disable function
  device: Add dev_<level>_once variants
  ath: ath9k: use debugfs_create_devm_seqfile() helper for seq_file entries
  ath: use seq_file api for ath9k debugfs files
  debugfs: add helper function to create device related seq_file
  drivers/base: cacheinfo: remove noisy error boot message
  Revert "core: platform: add warning if driver has no owner"
  drivers: base: support cpu cache information interface to userspace via sysfs
  drivers: base: add cpu_device_create to support per-cpu devices
  topology: replace custom attribute macros with standard DEVICE_ATTR*
  cpumask: factor out show_cpumap into separate helper function
  driver core: Fix unbalanced device reference in drivers_probe
  driver core: fix race with userland in device_add()
  sysfs/kernfs: make read requests on pre-alloc files use the buffer.
  sysfs/kernfs: allow attributes to request write buffer be pre-allocated.
  fs: sysfs: return EGBIG on write if offset is larger than file size
  ...
2014-12-14 16:10:09 -08:00

398 lines
10 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.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");