usb: gadget: udc-core: independent registration of gadgets and gadget drivers
Change behavior during registration of gadgets and
gadget drivers in udc-core. Instead of previous
approach when for successful probe of usb gadget driver
at least one usb gadget should be already registered
use another one where gadget drivers and gadgets
can be registered in udc-core independently.
Independent registration of gadgets and gadget drivers
is useful for built-in into kernel gadget and gadget
driver case - because it's possible that gadget is
really probed only on late_init stage (due to deferred
probe) whereas gadget driver's probe is silently failed
on module_init stage due to no any UDC added.
Also it is useful for modules case - now there is no
difference what module to insert first: gadget module
or gadget driver one.
Tested-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Ruslan Bilovol <ruslan.bilovol@gmail.com>
[simplified code as requested by Alan Stern and Felipe Balbi,
fixed checkpatch issues]
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Tested-by: Peter Chen <peter.chen@freescale.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
diff --git a/drivers/usb/gadget/udc/udc-core.c b/drivers/usb/gadget/udc/udc-core.c
index f76ebc8..fd73a3e 100644
--- a/drivers/usb/gadget/udc/udc-core.c
+++ b/drivers/usb/gadget/udc/udc-core.c
@@ -51,8 +51,12 @@
static struct class *udc_class;
static LIST_HEAD(udc_list);
+static LIST_HEAD(gadget_driver_pending_list);
static DEFINE_MUTEX(udc_lock);
+static int udc_bind_to_driver(struct usb_udc *udc,
+ struct usb_gadget_driver *driver);
+
/* ------------------------------------------------------------------------- */
#ifdef CONFIG_HAS_DMA
@@ -356,6 +360,7 @@
void (*release)(struct device *dev))
{
struct usb_udc *udc;
+ struct usb_gadget_driver *driver;
int ret = -ENOMEM;
udc = kzalloc(sizeof(*udc), GFP_KERNEL);
@@ -403,6 +408,18 @@
usb_gadget_set_state(gadget, USB_STATE_NOTATTACHED);
udc->vbus = true;
+ /* pick up one of pending gadget drivers */
+ list_for_each_entry(driver, &gadget_driver_pending_list, pending) {
+ if (!driver->udc_name || strcmp(driver->udc_name,
+ dev_name(&udc->dev)) == 0) {
+ ret = udc_bind_to_driver(udc, driver);
+ if (ret)
+ goto err4;
+ list_del(&driver->pending);
+ break;
+ }
+ }
+
mutex_unlock(&udc_lock);
return 0;
@@ -473,10 +490,14 @@
mutex_lock(&udc_lock);
list_del(&udc->list);
- mutex_unlock(&udc_lock);
- if (udc->driver)
+ if (udc->driver) {
+ struct usb_gadget_driver *driver = udc->driver;
+
usb_gadget_remove_driver(udc);
+ list_add(&driver->pending, &gadget_driver_pending_list);
+ }
+ mutex_unlock(&udc_lock);
kobject_uevent(&udc->dev.kobj, KOBJ_REMOVE);
flush_work(&gadget->work);
@@ -535,11 +556,7 @@
if (!ret)
break;
}
- if (ret)
- ret = -ENODEV;
- else if (udc->driver)
- ret = -EBUSY;
- else
+ if (!ret && !udc->driver)
goto found;
} else {
list_for_each_entry(udc, &udc_list, list) {
@@ -549,9 +566,11 @@
}
}
- pr_debug("couldn't find an available UDC\n");
+ list_add_tail(&driver->pending, &gadget_driver_pending_list);
+ pr_info("udc-core: couldn't find an available UDC - added [%s] to list of pending drivers\n",
+ driver->function);
mutex_unlock(&udc_lock);
- return ret;
+ return 0;
found:
ret = udc_bind_to_driver(udc, driver);
mutex_unlock(&udc_lock);
@@ -577,6 +596,10 @@
break;
}
+ if (ret) {
+ list_del(&driver->pending);
+ ret = 0;
+ }
mutex_unlock(&udc_lock);
return ret;
}