Re: [PATCH v7 03/14] usb: hcd.h: Add OTG to HCD interface

[Roger Quadros]

On 06/05/16 12:41, Peter Chen wrote:
> On Mon, May 02, 2016 at 03:18:46PM +0300, Roger Quadros wrote:
>> The OTG core will use struct otg_hcd_ops to interface
>> with the HCD controller.
>>
>> The main purpose of this interface is to avoid directly
>> calling HCD APIs from the OTG core as they
>> wouldn't be defined in the built-in symbol table if
>> CONFIG_USB is m.
>>
>> Signed-off-by: Roger Quadros <rogerq@xxxxxx>
>> Acked-by: Peter Chen <peter.chen@xxxxxxx>
> 
> Roger, after thinking more, I still think current dependency between
> OTG, HCD and gadget are too complicated. Since the OTG can't work
> if it is built as module, I suggest letting OTG depends on HCD &&
> USB_GADGET, and it is a boolean, in that case, we don't need to
> export any HCD and gadget ops, things will be much simpler.
> What's your opinion?

How will it work if HCD and USB_GADGET are modules and OTG is built-in?

cheers,
-roger

> 
> Peter
> 
>> ---
>>  include/linux/usb/hcd.h | 24 ++++++++++++++++++++++++
>>  1 file changed, 24 insertions(+)
>>
>> diff --git a/include/linux/usb/hcd.h b/include/linux/usb/hcd.h
>> index b98f831..861ccaa 100644
>> --- a/include/linux/usb/hcd.h
>> +++ b/include/linux/usb/hcd.h
>> @@ -399,6 +399,30 @@ struct hc_driver {
>>  
>>  };
>>  
>> +/**
>> + * struct otg_hcd_ops - Interface between OTG core and HCD
>> + *
>> + * Provided by the HCD core to allow the OTG core to interface with the HCD
>> + *
>> + * @add: function to add the HCD
>> + * @remove: function to remove the HCD
>> + * @usb_bus_start_enum: function to immediately start bus enumeration
>> + * @usb_control_msg: function to build and send of a control urb
>> + * @usb_hub_find_child: function to get pointer to the child device
>> + */
>> +struct otg_hcd_ops {
>> +	int (*add)(struct usb_hcd *hcd,
>> +		   unsigned int irqnum, unsigned long irqflags);
>> +	void (*remove)(struct usb_hcd *hcd);
>> +	int (*usb_bus_start_enum)(struct usb_bus *bus, unsigned int port_num);
>> +	int (*usb_control_msg)(struct usb_device *dev, unsigned int pipe,
>> +			       __u8 request, __u8 requesttype, __u16 value,
>> +			       __u16 index, void *data, __u16 size,
>> +			       int timeout);
>> +	struct usb_device * (*usb_hub_find_child)(struct usb_device *hdev,
>> +						  int port1);
>> +};
>> +
>>  static inline int hcd_giveback_urb_in_bh(struct usb_hcd *hcd)
>>  {
>>  	return hcd->driver->flags & HCD_BH;
>> -- 
>> 2.7.4
>>
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>