The user can bind any unused udc to specific gadget driver if there is no udc has already been binded to that gadget driver. For example: echo udc-0 > /sys/bus/usb_gadget/drivers/g_serial echo udc-1 > /sys/bus/usb_gadget/drivers/g_mass_storage There are three solutions to do manual binding: 1. If the udc driver or gadget driver can be built as modules - echo 0 > /sys/bus/usb_gadget/drivers_autoprobe - load udc or gadget driver - Do manual binding 2. If both udc driver and gadget are build in - Add "udc-core.manual_binding=1" to your bootargs - After rootfs has been mounted, clear the value of manual_binding using below command: echo 0 > /sys/module/udc_core/parameters/manual_binding - Do manual binding 3. Unbind all current bindings first, then rebind the udc to driver echo udc-0 > /sys/bus/usb_gadget/drivers/g_serial/unbind echo udc-1 > /sys/bus/usb_gadget/drivers/g_mass_storage/unbind echo udc-1 > /sys/bus/usb_gadget/drivers/g_serial/unbind echo udc-0 > /sys/bus/usb_gadget/drivers/g_mass_storage/unbind Signed-off-by: Peter Chen <peter.chen@xxxxxxxxxxxxx> --- drivers/usb/gadget/udc-core.c | 18 ++++++++++++++++++ 1 files changed, 18 insertions(+), 0 deletions(-) diff --git a/drivers/usb/gadget/udc-core.c b/drivers/usb/gadget/udc-core.c index be42acd..236e33e 100644 --- a/drivers/usb/gadget/udc-core.c +++ b/drivers/usb/gadget/udc-core.c @@ -47,6 +47,21 @@ static struct bus_type gadget_bus_type; static DEFINE_MUTEX(udc_lock); static DEFINE_IDA(udc_ida); +/* + * We can bind any unused udc to specfic driver after setting manual_binding + * eg: + * echo udc-0 > /sys/bus/usb_gadget/drivers/g_serial + * echo udc-1 > /sys/bus/usb_gadget/drivers/g_mass_storage + * + * How to use manual_binding: + * First, set manual_binding = 1 before drivers and devices are added to bus + * Second, set manual_binding = 0 + * Third, do manual_binding like above + */ +static bool manual_binding; +module_param(manual_binding, bool, S_IRUGO | S_IWUSR); +MODULE_PARM_DESC(manual_binding, "binding udc and gadget driver manully"); + /* ------------------------------------------------------------------------- */ #ifdef CONFIG_HAS_DMA @@ -571,6 +586,9 @@ static int usb_gadget_match(struct device *dev, struct device_driver *drv) container_of(drv, struct usb_gadget_driver, driver); bool dev_not_in_use = true, driver_not_in_use = true; + if (manual_binding) + return 0; + dev_dbg(dev, "%s: driver: %s\n", __func__, drv->name); udc = container_of(dev, struct usb_udc, dev); -- 1.7.8 -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
