[PATCH v6 1/4] usb: gadget: bind UDC by name passed via usb_gadget_driver structure

From: Marek Szyprowski
Date: Fri Nov 20 2015 - 03:54:28 EST


From: Ruslan Bilovol <ruslan.bilovol@xxxxxxxxx>

Introduce new 'udc_name' member to usb_gadget_driver structure.
The 'udc_name' is a name of UDC that usb_gadget_driver should
be bound to. If udc_name is NULL, it will be bound to any
available UDC.

Tested-by: Maxime Ripard <maxime.ripard@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Ruslan Bilovol <ruslan.bilovol@xxxxxxxxx>
Signed-off-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
---
drivers/usb/gadget/udc/udc-core.c | 24 +++++++++++++++++++-----
include/linux/usb/gadget.h | 4 ++++
2 files changed, 23 insertions(+), 5 deletions(-)

diff --git a/drivers/usb/gadget/udc/udc-core.c b/drivers/usb/gadget/udc/udc-core.c
index f660afb..429d64e 100644
--- a/drivers/usb/gadget/udc/udc-core.c
+++ b/drivers/usb/gadget/udc/udc-core.c
@@ -549,21 +549,35 @@ EXPORT_SYMBOL_GPL(usb_udc_attach_driver);
int usb_gadget_probe_driver(struct usb_gadget_driver *driver)
{
struct usb_udc *udc = NULL;
- int ret;
+ int ret = -ENODEV;

if (!driver || !driver->bind || !driver->setup)
return -EINVAL;

mutex_lock(&udc_lock);
- list_for_each_entry(udc, &udc_list, list) {
- /* For now we take the first one */
- if (!udc->driver)
+ if (driver->udc_name) {
+ list_for_each_entry(udc, &udc_list, list) {
+ ret = strcmp(driver->udc_name, dev_name(&udc->dev));
+ if (!ret)
+ break;
+ }
+ if (ret)
+ ret = -ENODEV;
+ else if (udc->driver)
+ ret = -EBUSY;
+ else
goto found;
+ } else {
+ list_for_each_entry(udc, &udc_list, list) {
+ /* For now we take the first one */
+ if (!udc->driver)
+ goto found;
+ }
}

pr_debug("couldn't find an available UDC\n");
mutex_unlock(&udc_lock);
- return -ENODEV;
+ return ret;
found:
ret = udc_bind_to_driver(udc, driver);
mutex_unlock(&udc_lock);
diff --git a/include/linux/usb/gadget.h b/include/linux/usb/gadget.h
index 3d583a1..b32e44f 100644
--- a/include/linux/usb/gadget.h
+++ b/include/linux/usb/gadget.h
@@ -1012,6 +1012,8 @@ static inline int usb_gadget_activate(struct usb_gadget *gadget)
* @reset: Invoked on USB bus reset. It is mandatory for all gadget drivers
* and should be called in_interrupt.
* @driver: Driver model state for this driver.
+ * @udc_name: A name of UDC this driver should be bound to. If udc_name is NULL,
+ * this driver will be bound to any available UDC.
*
* Devices are disabled till a gadget driver successfully bind()s, which
* means the driver will handle setup() requests needed to enumerate (and
@@ -1072,6 +1074,8 @@ struct usb_gadget_driver {

/* FIXME support safe rmmod */
struct device_driver driver;
+
+ char *udc_name;
};


--
1.9.2

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