2010/12/13 Felipe Balbi <balbi@xxxxxx>:
> Hi,
>
> On Mon, Dec 13, 2010 at 01:01:57AM +0800, tom.leiming@xxxxxxxxx wrote:
>>
>> From: Ming Lei <tom.leiming@xxxxxxxxx>
>>
>> This patch introduces musb_readb/musb_writeb function pointer,
>> so that we can use same musb_readb/musb_writeb in one single
>> binary image to help to support multiple machines.
>>
>> Signed-off-by: Ming Lei <tom.leiming@xxxxxxxxx>
>> ---
>> drivers/usb/musb/musb_core.c | 55
>> ++++++++++++++++++++++++++++++++++++++++++
>> drivers/usb/musb/musb_core.h | 3 ++
>> drivers/usb/musb/musb_io.h | 49 -------------------------------------
>> 3 files changed, 58 insertions(+), 49 deletions(-)
>>
>> diff --git a/drivers/usb/musb/musb_core.c b/drivers/usb/musb/musb_core.c
>> index dba20f8..ca3ae8b 100644
>> --- a/drivers/usb/musb/musb_core.c
>> +++ b/drivers/usb/musb/musb_core.c
>> @@ -135,6 +135,10 @@ MODULE_AUTHOR(DRIVER_AUTHOR);
>> MODULE_LICENSE("GPL");
>> MODULE_ALIAS("platform:" MUSB_DRIVER_NAME);
>>
>> +u8 (*musb_readb)(const void __iomem *addr, unsigned offset);
>> +EXPORT_SYMBOL(musb_readb);
>> +void (*musb_writeb)(void __iomem *addr, unsigned offset, u8 data);
>> +EXPORT_SYMBOL(musb_writeb);
>
> my idea for this was to have struct musb_io_ops. something like:
>
> struct musb_io_ops {
> u8 (*readb)(const void __iomem *addr, unsigned offset);
> void (*writeb)(const void __iomem *addr, unsigned offset, u8
> data);
>
> u16 (*readw)(....);
> void (*writew)(;...);
>
> u32 (*readl)();
> void (writel)();
> }
>
> then you have a pointer for that inside the struct musb_platform_ops, or
> maybe somewhere else. And you initialize the same way platform_ops, and
> if you don't have a field, you fallback to default implementation.
In fact, I think inline helper has a good performance, so it is better.
But no way to reach this if config option is not used, so I suggest using
inline helpers as far as possible.
--
Lei Ming
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