Dear Aneesh V, In message <4df7488a.6000...@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 -- DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: w...@denx.de "I dislike companies that have a we-are-the-high-priests-of-hardware- so-you'll-like-what-we-give-you attitude. I like commodity markets in which iron-and-silicon hawkers know that they exist to provide fast toys for software types like me to play with..." - Eric S. Raymond _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
