At 3:18 AM -0400 2001-05-03, Jeff Garzik wrote:
>"David S. Miller" wrote:
>>  There is a school of thought which believes that:
>>
>  > struct xdev_regs {
>>          u32 reg1;
>>          u32 reg2;
>>  };
>  >
>>          val = readl(&regs->reg2);
>>
>>  is cleaner than:
>>
>>  #define REG1 0x00
>>  #define REG2 0x04
>>
>>          val = readl(regs + REG2);
>>
>>  I'm personally ambivalent and believe that both cases should be allowed.
>
>Agreed...  Tangent a bit, I wanted to plug using macros which IMHO make
>code even more readable:
>
>       val = RTL_R32(REG2);
>       RTL_W32(REG2, val);
>
>Since these are driver-private, if you are only dealing with one chip
>you could even shorten things to "R32" and "W32", if that doesn't offend
>any sensibilities :)

With a little arithmetic behind the scenes and a NULL pointer to the 
struct xdev, you could have:

struct xdev_regs {
         u32 reg1;
         u32 reg2;
} *xdr = 0;

#define RTL_R32(REG) readl(cookie+(unsigned long)(&xdr->REG))

cookie = ioremap(blah, blah);

val = RTL_R32(reg2);

...and have the benefits of the R32 macro as well as the use of 
structure members.
-- 
/Jonathan Lundell.
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to