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

[kishon <kishon@ti.com>]

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@ti.com>
>> ---
>>   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