[U-Boot] [PATCH v3 02/10] armv7: add miscellaneous utility macros

Wolfgang Denk
2011-06-16T08:15:43Z

Dear Graeme Russ,

In message <BANLkTik3cXeMzU0qpxDLSQMtK-AbEoDCPQ@mail.gmail.com> you wrote:
>
> Now, that being said, I see no reason not to do the following if I had,
> for example, multiple serial port configuration registers which are all
> identical:
>
> /* num data bits is stored in bits 2-4 of the serial config register */
> #define DATA_BITS_MASK 0x001c
> #define DATA_BITS_OFFSET 2
>
> u32 set_serial_data_bits(u32 ser_cfg, u8 data_bits)
> {
> ser_cfg &= ~DATA_BITS_MASK;
> ser_cfg |= ((u32)ser_cfg << DATA_BITS_OFFSET) & ?DATA_BITS_MASK;
>
> return ser_cfg;
> }
>
> void serial_init(void)
> {
> u32 ser_cfg;
>
> for (i=0; i<NUM_SERIAL_PORTS; i++) {
> ser_cfg = read_serial_cfg(i);
> ser_cfg = set_serial_data_bits(ser_cfg, 7);
> write_serial_cfg(i, ser_cfg);
> }
> }

One reason for not doing this is that we should not reinvent the wheel
again and again, and instead use standard APIs.

I cannot find any such code in U-Boot, so I cannot check, but to me it
smells a lot as if this code should rather use clrsetbits_*() and
other proper I/O accessors.

Best regards,

Wolfgang Denk

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