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Commit a77196fc authored by Badhri Jagan Sridharan's avatar Badhri Jagan Sridharan Committed by Alistair Strachan
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ANDROID: usb: gadget: configfs: Add Uevent to notify userspace 



Android userspace UsbDeviceManager relies on the
uevents generated by the composition driver to
generate user notifications. This CL adds uevents
to be generated whenever USB changes its state
i.e. connected, disconnected, configured.

This CL also intercepts the setup requests from
the usb_core anb routes it to the specific
usb function if required.

Bug: 68755607
Bug: 120441124
Change-Id: Ib3d3a78255a532f7449dac286f776c2966caf8c1
[badhri: Migrate to using udc uevents from upstream sysfs.]
Signed-off-by: default avatarBadhri Jagan Sridharan <badhri@google.com>
[AmitP: Folded following android-4.9 commit changes into this patch
        9214c899f730 ("ANDROID: usb: gadget: configfs: handle gadget reset request for android")]
Signed-off-by: default avatarAmit Pundir <amit.pundir@linaro.org>
[astrachan: Folded change 5c899c9fd75d ("ANDROID: usb: gadget: configfs:
            fix null ptr in android_disconnect") into this patch]
Signed-off-by: default avatarAlistair Strachan <astrachan@google.com>
parent 2794c17f

drivers/usb/gadget/Kconfig

+8 −0
Original line number Diff line number Diff line
@@ -229,6 +229,14 @@ config USB_CONFIGFS 
	  appropriate symbolic links.

	  For more information see Documentation/usb/gadget_configfs.txt.



config USB_CONFIGFS_UEVENT

	bool "Uevent notification of Gadget state"

	depends on USB_CONFIGFS

	help

	  Enable uevent notifications to userspace when the gadget

	  state changes. The gadget can be in any of the following

	  three states: "CONNECTED/DISCONNECTED/CONFIGURED"



config USB_CONFIGFS_SERIAL

	bool "Generic serial bulk in/out"

	depends on USB_CONFIGFS

drivers/usb/gadget/configfs.c

+163 −3
Original line number Diff line number Diff line
@@ -10,6 +10,19 @@ 
#include "u_f.h"

#include "u_os_desc.h"



#ifdef CONFIG_USB_CONFIGFS_UEVENT

#include <linux/platform_device.h>

#include <linux/kdev_t.h>

#include <linux/usb/ch9.h>



#ifdef CONFIG_USB_CONFIGFS_F_ACC

extern int acc_ctrlrequest(struct usb_composite_dev *cdev,

				const struct usb_ctrlrequest *ctrl);

void acc_disconnect(void);

#endif

static struct class *android_class;

#endif



int check_user_usb_string(const char *name,

		struct usb_gadget_strings *stringtab_dev)

{
@@ -61,6 +74,12 @@ struct gadget_info { 
	bool use_os_desc;

	char b_vendor_code;

	char qw_sign[OS_STRING_QW_SIGN_LEN];

#ifdef CONFIG_USB_CONFIGFS_UEVENT

	bool connected;

	bool sw_connected;

	struct work_struct work;

	struct device *dev;

#endif

};



static inline struct gadget_info *to_gadget_info(struct config_item *item)
@@ -266,7 +285,7 @@ static ssize_t gadget_dev_desc_UDC_store(struct config_item *item, 


	mutex_lock(&gi->lock);



	if (!strlen(name)) {

	if (!strlen(name) || strcmp(name, "none") == 0) {

		ret = unregister_gadget(gi);

		if (ret)

			goto err;
@@ -1372,6 +1391,57 @@ static int configfs_composite_bind(struct usb_gadget *gadget, 
	return ret;

}



#ifdef CONFIG_USB_CONFIGFS_UEVENT

static void android_work(struct work_struct *data)

{

	struct gadget_info *gi = container_of(data, struct gadget_info, work);

	struct usb_composite_dev *cdev = &gi->cdev;

	char *disconnected[2] = { "USB_STATE=DISCONNECTED", NULL };

	char *connected[2]    = { "USB_STATE=CONNECTED", NULL };

	char *configured[2]   = { "USB_STATE=CONFIGURED", NULL };

	/* 0-connected 1-configured 2-disconnected*/

	bool status[3] = { false, false, false };

	unsigned long flags;

	bool uevent_sent = false;



	spin_lock_irqsave(&cdev->lock, flags);

	if (cdev->config)

		status[1] = true;



	if (gi->connected != gi->sw_connected) {

		if (gi->connected)

			status[0] = true;

		else

			status[2] = true;

		gi->sw_connected = gi->connected;

	}

	spin_unlock_irqrestore(&cdev->lock, flags);



	if (status[0]) {

		kobject_uevent_env(&gi->dev->kobj, KOBJ_CHANGE, connected);

		pr_info("%s: sent uevent %s\n", __func__, connected[0]);

		uevent_sent = true;

	}



	if (status[1]) {

		kobject_uevent_env(&gi->dev->kobj, KOBJ_CHANGE, configured);

		pr_info("%s: sent uevent %s\n", __func__, configured[0]);

		uevent_sent = true;

	}



	if (status[2]) {

		kobject_uevent_env(&gi->dev->kobj, KOBJ_CHANGE, disconnected);

		pr_info("%s: sent uevent %s\n", __func__, disconnected[0]);

		uevent_sent = true;

	}



	if (!uevent_sent) {

		pr_info("%s: did not send uevent (%d %d %p)\n", __func__,

			gi->connected, gi->sw_connected, cdev->config);

	}

}

#endif



static void configfs_composite_unbind(struct usb_gadget *gadget)

{

	struct usb_composite_dev	*cdev;
@@ -1391,14 +1461,91 @@ static void configfs_composite_unbind(struct usb_gadget *gadget) 
	set_gadget_data(gadget, NULL);

}



#ifdef CONFIG_USB_CONFIGFS_UEVENT

static int android_setup(struct usb_gadget *gadget,

			const struct usb_ctrlrequest *c)

{

	struct usb_composite_dev *cdev = get_gadget_data(gadget);

	unsigned long flags;

	struct gadget_info *gi = container_of(cdev, struct gadget_info, cdev);

	int value = -EOPNOTSUPP;

	struct usb_function_instance *fi;



	spin_lock_irqsave(&cdev->lock, flags);

	if (!gi->connected) {

		gi->connected = 1;

		schedule_work(&gi->work);

	}

	spin_unlock_irqrestore(&cdev->lock, flags);

	list_for_each_entry(fi, &gi->available_func, cfs_list) {

		if (fi != NULL && fi->f != NULL && fi->f->setup != NULL) {

			value = fi->f->setup(fi->f, c);

			if (value >= 0)

				break;

		}

	}



#ifdef CONFIG_USB_CONFIGFS_F_ACC

	if (value < 0)

		value = acc_ctrlrequest(cdev, c);

#endif



	if (value < 0)

		value = composite_setup(gadget, c);



	spin_lock_irqsave(&cdev->lock, flags);

	if (c->bRequest == USB_REQ_SET_CONFIGURATION &&

						cdev->config) {

		schedule_work(&gi->work);

	}

	spin_unlock_irqrestore(&cdev->lock, flags);



	return value;

}



static void android_disconnect(struct usb_gadget *gadget)

{

	struct usb_composite_dev        *cdev = get_gadget_data(gadget);

	struct gadget_info *gi = container_of(cdev, struct gadget_info, cdev);



	/* FIXME: There's a race between usb_gadget_udc_stop() which is likely

	 * to set the gadget driver to NULL in the udc driver and this drivers

	 * gadget disconnect fn which likely checks for the gadget driver to

	 * be a null ptr. It happens that unbind (doing set_gadget_data(NULL))

	 * is called before the gadget driver is set to NULL and the udc driver

	 * calls disconnect fn which results in cdev being a null ptr.

	 */

	if (cdev == NULL) {

		WARN(1, "%s: gadget driver already disconnected\n", __func__);

		return;

	}



	/* accessory HID support can be active while the

		accessory function is not actually enabled,

		so we need to inform it when we are disconnected.

	*/



#ifdef CONFIG_USB_CONFIGFS_F_ACC

	acc_disconnect();

#endif

	gi->connected = 0;

	schedule_work(&gi->work);

	composite_disconnect(gadget);

}

#endif



static const struct usb_gadget_driver configfs_driver_template = {

	.bind           = configfs_composite_bind,

	.unbind         = configfs_composite_unbind,



#ifdef CONFIG_USB_CONFIGFS_UEVENT

	.setup          = android_setup,

	.reset          = android_disconnect,

	.disconnect     = android_disconnect,

#else

	.setup          = composite_setup,

	.reset          = composite_disconnect,

	.disconnect     = composite_disconnect,



#endif

	.suspend	= composite_suspend,

	.resume		= composite_resume,
@@ -1458,6 +1605,12 @@ static struct config_group *gadgets_make( 
	gi->composite.gadget_driver.function = kstrdup(name, GFP_KERNEL);

	gi->composite.name = gi->composite.gadget_driver.function;



#ifdef CONFIG_USB_CONFIGFS_UEVENT

	INIT_WORK(&gi->work, android_work);

	gi->dev = device_create(android_class, NULL,

				MKDEV(0, 0), NULL, "android0");

#endif



	if (!gi->composite.gadget_driver.function)

		goto err;
@@ -1509,6 +1662,13 @@ static int __init gadget_cfs_init(void) 
	config_group_init(&gadget_subsys.su_group);



	ret = configfs_register_subsystem(&gadget_subsys);



#ifdef CONFIG_USB_CONFIGFS_UEVENT

	android_class = class_create(THIS_MODULE, "android_usb");

	if (IS_ERR(android_class))

		return PTR_ERR(android_class);

#endif



	return ret;

}

module_init(gadget_cfs_init);