Re: [PATCH 2/3] usb: common: add helper to get role-switch-default-mode

[Chunfeng Yun <chunfeng.yun@mediatek.com>]

On Thu, 2021-05-27 at 09:28 +0200, Greg Kroah-Hartman wrote:
> On Tue, May 25, 2021 at 04:59:24PM +0800, Chunfeng Yun wrote:
> > Add helper to get "role-switch-default-mode", and convert it
> > to the corresponding enum usb_dr_mode
> > 
> > Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
> > ---
> >  drivers/usb/common/common.c | 20 ++++++++++++++++++++
> >  include/linux/usb/otg.h     |  1 +
> >  2 files changed, 21 insertions(+)
> > 
> > diff --git a/drivers/usb/common/common.c b/drivers/usb/common/common.c
> > index fff318597337..78a625a4e526 100644
> > --- a/drivers/usb/common/common.c
> > +++ b/drivers/usb/common/common.c
> > @@ -207,6 +207,26 @@ enum usb_dr_mode usb_get_dr_mode(struct device *dev)
> >  }
> >  EXPORT_SYMBOL_GPL(usb_get_dr_mode);
> >  
> > +/**
> > + * usb_get_role_switch_default_mode - Get default mode for given device
> > + * @dev: Pointer to the given device
> > + *
> > + * The function gets string from property 'role-switch-default-mode',
> > + * and returns the corresponding enum usb_dr_mode.
> > + */
> > +enum usb_dr_mode usb_get_role_switch_default_mode(struct device *dev)
> > +{
> > +	const char *str;
> > +	int ret;
> > +
> > +	ret = device_property_read_string(dev, "role-switch-default-mode", &str);
> > +	if (ret < 0)
> > +		return USB_DR_MODE_UNKNOWN;
> > +
> > +	return usb_get_dr_mode_from_string(str);
> > +}
> > +EXPORT_SYMBOL_GPL(usb_get_role_switch_default_mode);
> > +
> >  /**
> >   * usb_decode_interval - Decode bInterval into the time expressed in 1us unit
> >   * @epd: The descriptor of the endpoint
> > diff --git a/include/linux/usb/otg.h b/include/linux/usb/otg.h
> > index a86ee6aad51b..bde313c97fb6 100644
> > --- a/include/linux/usb/otg.h
> > +++ b/include/linux/usb/otg.h
> > @@ -121,5 +121,6 @@ enum usb_dr_mode {
> >  };
> >  
> >  extern enum usb_dr_mode usb_get_dr_mode(struct device *dev);
> > +extern enum usb_dr_mode usb_get_role_switch_default_mode(struct device *dev);
> 
> What other code outside of the dwc3 driver will ever need to call this?
I prepare a series of pathes for mtu3, and will support
"role-switch-default-mode" property

> 
> thanks,
> 
> greg k-h