On Sat, 20 Nov 2010, Blair wrote:
> Is it a bad idea to open /dev/mem more than once in different sections of
> a program when you want to access different EP93xx registers?
Not bad, just wastefull.
> Let's say
> you want to use the BGPIO lines, the HGPIO lines, and maybe the buffered
> input lines, and SPI lines which all have different base addresses.
> Should you open /dev/mem and mmap for each of these areas or should you
> open /dev/mem once and pass that value to individual mmap calls?
Open once, save the file descriptor returned and use that whenever you need
to call mmap. I usually have an init function to setup all memory access
pointers that gets called once at program start, then just use the ptrs as
required.
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