Hi Thierry, On 19 August 2014 07:12, Thierry Reding <thierry.red...@gmail.com> wrote: > On Tue, Aug 19, 2014 at 06:55:18AM -0600, Simon Glass wrote: >> On 19 August 2014 05:35, Thierry Reding <thierry.red...@gmail.com> wrote: > [...] >> > The Linux kernel handles this by wrapping it in an of_read_number() >> > helper and always returning u64, like this: >> > >> > static inline u64 of_read_number(const __be32 *cell, int size) >> > { >> > u64 r = 0; >> > >> > while (size--) >> > r = (r << 32) | be32_to_cpu(*(cell++)); >> > >> > return r; >> > } >> > >> > It obviously only works for size in { 0, 1, 2 }, but I can add a helper >> > like that if you want. >> >> >> That looks good. It works for the cases we need and it's obvious later >> where the logic is if we want to extend it. > > This is what I have for U-Boot currently. > > static fdt_addr_t fdtdec_get_address(const fdt32_t *ptr, unsigned int cells) > { > fdt_addr_t addr = 0; > > while (cells--) > /* do the shift in two steps to avoid warning on 32-bit */ > addr = (addr << 16) << 16 | fdt32_to_cpu(*ptr++);
Odd warning! Does 32UL help? > > return addr; > } > > I use the same function to parse the size field of reg entries, even > though the types aren't technically the same. But making the types > consistent would duplicate the above exactly, so I'm not sure it's worth > it. Seems fine. > > Alternatively perhaps something like this could be done: > > static u64 fdtdec_get_number(const fdt32_t *ptr, unsigned int cells) > { > /* the above */ > } > > static fdt_addr_t fdtdec_get_address(const fdt32_t *ptr, unsigned int > cells) > { > return fdtdec_get_number(ptr, cells); > } > > static fdt_size_t fdtdec_get_size(const fdt32_t *ptr, unsigned int > cells) > { > return fdtdec_get_number(ptr, cells); > } > > Again, I'm not sure it's really worth the trouble since fdt_addr_t and > fdt_size_t are both always either u32 or u64. Yes, although I suppose ultimately these might be 64-bit always, Perhaps we should merge the types? Regards, Simon _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot