Dear Wolfgang,
On Tuesday 14 June 2011 04:21 PM, Wolfgang Denk wrote:
Dear Aneesh V,
In message4DF71FBF.6030408@ti.com you wrote:
As I start re-working on my patches I realize that there is no alternative to get_bit_field(). clrsetbits_le32() works as an alternative for set_bit_field() but I couldn't find anything in io.h that could replace get_bit_field(). The only option I seem to have is to mask and shift directly every time. Is that what you prefer over get_bit_field()?
I don't understand this comment.
You should NOT use clrsetbits_*() instead of set_bit_field() - depending on what you want to do, clrbits_*() or setbits_*() are better choices for simple operations.
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_*()
Also please notice that none of clrbits_*(), setbits_*() or clrsetbits_*() perform any masking or shifting. If you don't want to do this explicitly when using the macro, you can hide it in respective definitions of the mask values. I showed how this could be done in the examples I posted in the thread with Simon.
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?
br, Aneesh