Re: [RFC PATCH 1/6] usb: otg: Add an API to bind the USB controllerand PHY

[kishon]

Hi,

On Thursday 17 January 2013 03:07 PM, Roger Quadros wrote:
> On 01/16/2013 05:00 PM, Kishon Vijay Abraham I wrote:
> > New platforms are added which has multiple PHY's (of same type) and
> > which has multiple USB controllers. The binding information has to be
> > present in the PHY library (otg.c) in order for it to return the
> > appropriate PHY whenever the USB controller request for the PHY. So
> > added a new API to pass the binding information. This API should be
> > called by platform specific initialization code.
> >
> > Signed-off-by: Kishon Vijay Abraham I <kishon@xxxxxx>
> > ---
> >   drivers/usb/otg/otg.c   |   37 +++++++++++++++++++++++++++++++++++++
> >   include/linux/usb/phy.h |   22 ++++++++++++++++++++++
> >   2 files changed, 59 insertions(+)
> >
> > diff --git a/drivers/usb/otg/otg.c b/drivers/usb/otg/otg.c
> > index a30c041..492ba2f 100644
> > --- a/drivers/usb/otg/otg.c
> > +++ b/drivers/usb/otg/otg.c
> > @@ -18,6 +18,7 @@
> >   #include <linux/usb/otg.h>
> >
> >   static LIST_HEAD(phy_list);
> > +static LIST_HEAD(phy_bind_list);
> >   static DEFINE_SPINLOCK(phy_lock);
> >
> >   static struct usb_phy *__usb_find_phy(struct list_head *list,
> > @@ -201,6 +202,42 @@ void usb_remove_phy(struct usb_phy *x)
> >   }
> >   EXPORT_SYMBOL(usb_remove_phy);
> >
> > +/**
> > + * usb_bind_phy - bind the phy and the controller that uses the phy
> > + * @dev_name: the device name of the device that will bind to the phy
> > + * @index: index to specify the port number
> > + * @phy_dev_name: the device name of the phy
> > + *
> > + * Fills the phy_bind structure with the dev_name and phy_dev_name. This will
> > + * be used when the phy driver registers the phy and when the controller
> > + * requests this phy.
> > + *
> > + * To be used by platform specific initialization code.
> > + */
> > +struct usb_phy_bind __init *usb_bind_phy(const char *dev_name, u8 index,
> > +				const char *phy_dev_name)
> > +{
> > +	struct usb_phy_bind *phy_bind;
> > +	unsigned long flags;
> > +
> > +	phy_bind = kzalloc(sizeof(*phy_bind), GFP_KERNEL);
> > +	if (!phy_bind) {
> > +		pr_err("phy_bind(): No memory for phy_bind");
>
> Function name in comment doesn't match the actual.
> Instead, you could use
> 	pr_err("%s ...", __func__);
>
> > +		return ERR_PTR(-ENOMEM);
> > +	}
> > +
> > +	phy_bind->dev_name = dev_name;
> > +	phy_bind->phy_dev_name = phy_dev_name;
> > +	phy_bind->index = index;
> > +
> > +	spin_lock_irqsave(&phy_lock, flags);
> > +	list_add_tail(&phy_bind->list, &phy_bind_list);
> > +	spin_unlock_irqrestore(&phy_lock, flags);
> > +
> > +	return phy_bind;
> > +}
> > +EXPORT_SYMBOL_GPL(usb_bind_phy);
> > +
> >   const char *otg_state_string(enum usb_otg_state state)
> >   {
> >   	switch (state) {
> > diff --git a/include/linux/usb/phy.h b/include/linux/usb/phy.h
> > index a29ae1e..fbeab1a 100644
> > --- a/include/linux/usb/phy.h
> > +++ b/include/linux/usb/phy.h
> > @@ -106,6 +106,21 @@ struct usb_phy {
> >   			enum usb_device_speed speed);
> >   };
> >
> > +/**
> > + * struct usb_phy_bind - represent the binding for the phy
> > + * @dev_name: the device name of the device that will bind to the phy
> > + * @phy_dev_name: the device name of the phy
> > + * @index: used if a single controller uses multiple phys
> > + * @phy: reference to the phy
> > + * @list: to maintain a linked list of the binding information
> > + */
> > +struct usb_phy_bind {
> > +	const char	*dev_name;
> > +	const char	*phy_dev_name;
> > +	u8		index;
> > +	struct usb_phy	*phy;
> > +	struct list_head list;
> > +};
> >
> >   /* for board-specific init logic */
> >   extern int usb_add_phy(struct usb_phy *, enum usb_phy_type type);
> > @@ -151,6 +166,8 @@ extern struct usb_phy *devm_usb_get_phy(struct device *dev,
> >   	enum usb_phy_type type);
> >   extern void usb_put_phy(struct usb_phy *);
> >   extern void devm_usb_put_phy(struct device *dev, struct usb_phy *x);
> > +extern struct usb_phy_bind *usb_bind_phy(const char *dev_name, u8 index,
> > +				const char *phy_dev_name);
> >   #else
> >   static inline struct usb_phy *usb_get_phy(enum usb_phy_type type)
> >   {
> > @@ -171,6 +188,11 @@ static inline void devm_usb_put_phy(struct device *dev, struct usb_phy *x)
> >   {
> >   }
> >
> > +static inline struct usb_phy_bind *usb_bind_phy(const char *dev_name, u8 index,
> > +				const char *phy_dev_name)
> > +{
> > +	return NULL;
> > +}
> >   #endif
> >
> >   static inline int
>
> Controllers like ehci-omap which don't need OTG functionality would
> benefit from this API. Can we make these PHY APIs not dependent on OTG /
> OTG_UTILS?

Actually much of whatever is in otg.c can be used by controllers which 
don't have OTG functionality (except otg_state_string). I vaguely 
remember, there was a patch that renamed otg.c to phy.c etc.. I'm not 
sure what happened to that.

Thanks
Kishon
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