This is useful on gadgets that depend on userland
daemons to function properly. We can delay connection
to the host until userland is ready.
Signed-off-by: Felipe Balbi <balbi@xxxxxx>
---
drivers/usb/gadget/composite.c | 3 ++-
drivers/usb/gadget/udc-core.c | 26 ++++++++++++++++++++++++--
include/linux/usb/composite.h | 4 ++++
include/linux/usb/gadget.h | 3 +++
4 files changed, 33 insertions(+), 3 deletions(-)
diff --git a/drivers/usb/gadget/composite.c b/drivers/usb/gadget/composite.c
index 7c821de..790ccf2 100644
--- a/drivers/usb/gadget/composite.c
+++ b/drivers/usb/gadget/composite.c
@@ -1784,8 +1784,9 @@ int usb_composite_probe(struct usb_composite_driver *driver)
driver->name = "composite";
driver->gadget_driver = composite_driver_template;
- gadget_driver = &driver->gadget_driver;
+ gadget_driver = &driver->gadget_driver;
+ gadget_driver->controls_pullups = driver->controls_pullups;
gadget_driver->function = (char *) driver->name;
gadget_driver->driver.name = driver->name;
gadget_driver->max_speed = driver->max_speed;
diff --git a/drivers/usb/gadget/udc-core.c b/drivers/usb/gadget/udc-core.c
index 8a1eeb2..c0f4fca 100644
--- a/drivers/usb/gadget/udc-core.c
+++ b/drivers/usb/gadget/udc-core.c
@@ -235,7 +235,18 @@ static void usb_gadget_remove_driver(struct usb_udc *udc)
kobject_uevent(&udc->dev.kobj, KOBJ_CHANGE);
- usb_gadget_disconnect(udc->gadget);
+ /*
+ * NOTICE: if gadget driver wants to control
+ * pullup, it needs to make sure that when
+ * user tries to rmmod the gadget driver, it
+ * will disconnect the pullups before returning
+ * from its ->unbind() method.
+ *
+ * We are truly trusting the gadget driver here.
+ */
+ if (!udc->driver->controls_pullups)
+ usb_gadget_disconnect(udc->gadget);
+
udc->driver->disconnect(udc->gadget);
udc->driver->unbind(udc->gadget);
usb_gadget_udc_stop(udc->gadget, udc->driver);
@@ -300,7 +311,18 @@ static int udc_bind_to_driver(struct usb_udc *udc, struct usb_gadget_driver *dri
driver->unbind(udc->gadget);
goto err1;
}
- usb_gadget_connect(udc->gadget);
+
+ /*
+ * NOTICE: if gadget driver wants to control
+ * pullups, it needs to make sure its calls
+ * to usb_function_activate() and
+ * usb_function_deactivate() are balanced,
+ * otherwise gadget_driver will never enumerate.
+ *
+ * We are truly trusting the gadget driver here.
+ */
+ if (!driver->controls_pullups)
+ usb_gadget_connect(udc->gadget);
kobject_uevent(&udc->dev.kobj, KOBJ_CHANGE);
return 0;
diff --git a/include/linux/usb/composite.h b/include/linux/usb/composite.h
index 3c671c1..7ae797c 100644
--- a/include/linux/usb/composite.h
+++ b/include/linux/usb/composite.h
@@ -157,6 +157,7 @@ struct usb_function {
int (*get_status)(struct usb_function *);
int (*func_suspend)(struct usb_function *,
u8 suspend_opt);
+
/* private: */
/* internals */
struct list_head list;
@@ -279,6 +280,8 @@ enum {
* @max_speed: Highest speed the driver supports.
* @needs_serial: set to 1 if the gadget needs userspace to provide
* a serial number. If one is not provided, warning will be printed.
+ * @controls_pullups: this driver will control pullup and udc-core shouldn't
+ * enable it by default
* @bind: (REQUIRED) Used to allocate resources that are shared across the
* whole device, such as string IDs, and add its configurations using
* @usb_add_config(). This may fail by returning a negative errno
@@ -308,6 +311,7 @@ struct usb_composite_driver {
struct usb_gadget_strings **strings;
enum usb_device_speed max_speed;
unsigned needs_serial:1;
+ unsigned controls_pullups:1;
int (*bind)(struct usb_composite_dev *cdev);
int (*unbind)(struct usb_composite_dev *);
diff --git a/include/linux/usb/gadget.h b/include/linux/usb/gadget.h
index 32b734d..87971fa 100644
--- a/include/linux/usb/gadget.h
+++ b/include/linux/usb/gadget.h
@@ -774,6 +774,7 @@ static inline int usb_gadget_disconnect(struct usb_gadget *gadget)
* @suspend: Invoked on USB suspend. May be called in_interrupt.
* @resume: Invoked on USB resume. May be called in_interrupt.
* @driver: Driver model state for this driver.
+ * @controls_pullups: tells udc-core to not enable pullups by default
*
* Devices are disabled till a gadget driver successfully bind()s, which
* means the driver will handle setup() requests needed to enumerate (and
@@ -833,6 +834,8 @@ struct usb_gadget_driver {
/* FIXME support safe rmmod */
struct device_driver driver;
+
+ unsigned controls_pullups:1;
};
--
1.8.1.rc1.5.g7e0651a
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