@@ -464,6 +464,14 @@ config USB_CONFIGFS_F_MTP
the file level. Thus exposing the relevant content but hiding
the system/restricted files.
+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"
+
source "drivers/usb/gadget/legacy/Kconfig"
endchoice
@@ -9,6 +9,15 @@
#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>
+
+static struct class *usb_gadget_class;
+static struct device *usb_gadget_device;
+#endif
+
int check_user_usb_string(const char *name,
struct usb_gadget_strings *stringtab_dev)
{
@@ -63,6 +72,12 @@ 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
};
struct config_usb_cfg {
@@ -1444,13 +1459,143 @@ static void configfs_composite_unbind(struct usb_gadget *gadget)
set_gadget_data(gadget, NULL);
}
+#ifdef CONFIG_USB_CONFIGFS_UEVENT
+static ssize_t state_show(struct device *pdev, struct device_attribute *attr,
+ char *buf)
+{
+ struct gadget_info *dev = dev_get_drvdata(pdev);
+ struct usb_composite_dev *cdev;
+ char *state = "DISCONNECTED";
+ unsigned long flags;
+
+ if (!dev)
+ goto out;
+
+ cdev = &dev->cdev;
+
+ if (!cdev)
+ goto out;
+
+ spin_lock_irqsave(&cdev->lock, flags);
+ if (cdev->config)
+ state = "CONFIGURED";
+ else if (dev->connected)
+ state = "CONNECTED";
+ spin_unlock_irqrestore(&cdev->lock, flags);
+out:
+ return sprintf(buf, "%s\n", state);
+}
+
+static DEVICE_ATTR(state, S_IRUGO, state_show, NULL);
+
+static struct device_attribute *cfs_usb_attributes[] = {
+ &dev_attr_state,
+ NULL
+};
+
+static void cfs_uevent_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(&usb_gadget_device->kobj,
+ KOBJ_CHANGE, connected);
+ pr_info("%s: sent uevent %s\n", __func__, connected[0]);
+ uevent_sent = true;
+ }
+
+ if (status[1]) {
+ kobject_uevent_env(&usb_gadget_device->kobj,
+ KOBJ_CHANGE, configured);
+ pr_info("%s: sent uevent %s\n", __func__, configured[0]);
+ uevent_sent = true;
+ }
+
+ if (status[2]) {
+ kobject_uevent_env(&usb_gadget_device->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);
+ }
+}
+
+static int cfs_uevent_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;
+
+ spin_lock_irqsave(&cdev->lock, flags);
+ if (!gi->connected) {
+ gi->connected = 1;
+ schedule_work(&gi->work);
+ }
+ spin_unlock_irqrestore(&cdev->lock, flags);
+
+ 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 cfs_uevent_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);
+
+ 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 = cfs_uevent_setup,
+ .reset = cfs_uevent_disconnect,
+ .disconnect = cfs_uevent_disconnect,
+#else
.setup = composite_setup,
.reset = composite_disconnect,
.disconnect = composite_disconnect,
+#endif
.suspend = composite_suspend,
.resume = composite_resume,
@@ -1462,16 +1607,21 @@ static const struct usb_gadget_driver configfs_driver_template = {
},
};
+
static struct config_group *gadgets_make(
struct config_group *group,
const char *name)
{
struct gadget_info *gi;
+#ifdef CONFIG_USB_CONFIGFS_UEVENT
+ struct device_attribute **attrs;
+ struct device_attribute *attr;
+ int err;
+#endif
gi = kzalloc(sizeof(*gi), GFP_KERNEL);
if (!gi)
return ERR_PTR(-ENOMEM);
-
gi->group.default_groups = gi->default_groups;
gi->group.default_groups[0] = &gi->functions_group;
gi->group.default_groups[1] = &gi->configs_group;
@@ -1507,9 +1657,26 @@ static struct config_group *gadgets_make(
gi->composite.gadget_driver.function = kstrdup(name, GFP_KERNEL);
gi->composite.name = gi->composite.gadget_driver.function;
- if (!gi->composite.gadget_driver.function)
+#ifdef CONFIG_USB_CONFIGFS_UEVENT
+ INIT_WORK(&gi->work, cfs_uevent_work);
+ usb_gadget_device = device_create(usb_gadget_class, NULL,
+ MKDEV(0, 0), NULL, "android0");
+ if (IS_ERR(usb_gadget_device))
goto err;
+ dev_set_drvdata(usb_gadget_device, gi);
+
+ attrs = cfs_usb_attributes;
+ while ((attr = *attrs++)) {
+ err = device_create_file(usb_gadget_device, attr);
+ if (err)
+ goto err1;
+ }
+#endif
+
+ if (!gi->composite.gadget_driver.function)
+ goto err1;
+
#ifdef CONFIG_USB_OTG
gi->otg.bLength = sizeof(struct usb_otg_descriptor);
gi->otg.bDescriptorType = USB_DT_OTG;
@@ -1519,13 +1686,31 @@ static struct config_group *gadgets_make(
config_group_init_type_name(&gi->group, name,
&gadget_root_type);
return &gi->group;
+
+err1:
+#ifdef CONFIG_USB_CONFIGFS_UEVENT
+ attrs = cfs_usb_attributes;
+ while ((attr = *attrs++))
+ device_remove_file(usb_gadget_device, attr);
+ device_destroy(usb_gadget_device->class, usb_gadget_device->devt);
err:
+#endif
kfree(gi);
return ERR_PTR(-ENOMEM);
}
static void gadgets_drop(struct config_group *group, struct config_item *item)
{
+#ifdef CONFIG_USB_CONFIGFS_UEVENT
+ struct device_attribute **attrs;
+ struct device_attribute *attr;
+
+ attrs = cfs_usb_attributes;
+ while ((attr = *attrs++))
+ device_remove_file(usb_gadget_device, attr);
+ device_destroy(usb_gadget_device->class, usb_gadget_device->devt);
+#endif
+
config_item_put(item);
}
@@ -1564,6 +1749,13 @@ 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
+ usb_gadget_class = class_create(THIS_MODULE, "android_usb");
+ if (IS_ERR(usb_gadget_class))
+ return PTR_ERR(usb_gadget_class);
+#endif
+
return ret;
}
module_init(gadget_cfs_init);
@@ -1571,5 +1763,10 @@ module_init(gadget_cfs_init);
static void __exit gadget_cfs_exit(void)
{
configfs_unregister_subsystem(&gadget_subsys);
+#ifdef CONFIG_USB_CONFIGFS_UEVENT
+ if (!IS_ERR(usb_gadget_class))
+ class_destroy(usb_gadget_class);
+#endif
+
}
module_exit(gadget_cfs_exit);
This is more of an RFC than an actual submission. There are few scattered #ifdefs..#endifs here and there which still need to be taken care of before going for actual submission. Currently there is no way with the upstream ConfigFS gadget to communicate state changes (connected, disconnected, configured), at the gadget level. Instead such state changes are handled function by function independently I presume. This is problematic, because some coordination between the functions, across the state changes, may be desired at the userspace level. Thus to address this issue, this patch send uevents to allow userspace to be notified of these usb state changes, allowing userspace to respond and configure the configfs gadget appropriately. This patch is based on an Android patchset originaly authored by Badhri Jagan Sridharan <Badhri@google.com> to send uevent notifications to Android userpace for USB state changes. I've folded his patches together and modified it enough that I don't want him to be blamed for any mistakes I've made condensing his patches down. This patch introduces USB_CONFIGFS_UEVENT Kconfig to handle userspace notifications of usb state changes, and add setup and disconnect functions to intercept the setup requests from the usb_core. It also creates a sysfs device class entry and a device attribute (state) to read and respond to gadget's current state from userspace. As of now this sysfs device class (/sys/class/android_usb) and gadget device (/sys/class/android_usb/android0) with state attribute (/sys/class/android_usb/android0/state) are strictly tied up to facilitate Android userspace requests. But going forward we may want to bring all function devices (hid, printer etc) under a unified usb gadget device class e.g. /sys/class/usb_gadget/g_{func0,func1} etc.. Also I think it make sense to add this state attribute to the configfs usb gadget itself i.e. have something like /config/usb_gadget/g1/state to read USB gadget's current state. Since it is going to be consistent throughout all the functions tied up to that gadget. Again this is just an initial RFC, thoughts and feedback would be greatly appreciated. Cc: Mike Lockwood <lockwood@android.com> Cc: Benoit Goby <benoit@android.com> Cc: Colin Cross <ccross@android.com> Cc: Arve Hjønnevåg <arve@android.com> Cc: Peter Oh <poh@broadcom.com> Cc: Greg Hackmann <ghackmann@google.com> Cc: Badhri Jagan Sridharan <Badhri@google.com> Cc: Android Kernel Team <kernel-team@android.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Felipe Balbi <balbi@ti.com> Cc: Andrzej Pietrasiewicz <andrzej.p@samsung.com> Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Cc: Yegor Yefremov <yegorslists@googlemail.com> Cc: Philippe Reynes <tremyfr@gmail.com> Cc: John Stultz <john.stultz@linaro.org> Cc: Sumit Semwal <sumit.semwal@linaro.org> Signed-off-by: Amit Pundir <amit.pundir@linaro.org> --- drivers/usb/gadget/Kconfig | 8 ++ drivers/usb/gadget/configfs.c | 201 +++++++++++++++++++++++++++++++++++++++++- 2 files changed, 207 insertions(+), 2 deletions(-)