Dear Aneesh V,
In message 4DF7488A.6000909@ti.com you wrote:
Yes. I have seen those macros. But more often than not the bit field is more than 1 bit wide and the value to be set is not necessarily all 0's or all 1's. That's why I have to use clrsetbits_*()
I see. In such a case (and only then) clrsetbits_*() is indeed the right choice.
The problem I have to deal with is different. get_bit_field() was intended to extract bit fields from an integer. So, the target usage will be something like this(where a, b, and c are bit fields in register my_reg)
u32 my_reg, a_val, b_val, c_val;
u32 my_reg = readl(my_reg_addr);
a_val = get_bit_field(my_reg, a_mask); b_val = get_bit_field(my_reg, b_mask); c_val = get_bit_field(my_reg, c_mask);
Do you see an alternative method for doing this using the standard macros?
Please see the example given here:
http://article.gmane.org/gmane.comp.boot-loaders.u-boot/101146
Looking closer, the "FIELD_VAL" macro alone will probably not suffice, as you need both shift directions, like that:
#define FIELD_SHIFT 16 #define FIELD_MASK 0xF
#define FIELD_BITS(x) (x << 16) #define FIELD_MASK FIELD_BITS(0xF) #define FIELD_VAL(x) ((x & FIELD_MASK) >> 16)
The code would then look something like this:
my_reg = readl(my_reg_addr);
a_val = A_VAL(my_reg); b_val = B_VAL(my_reg); c_val = C_VAL(my_reg);
...or similar.
Best regards,
Wolfgang Denk