Hi, > Dear Dave Aldridge, > > In message <1314877212-31552-1-git-send-email-fovs...@gmail.com> you wrote: >> If CONFIG_SYS_NS16550_MEM32 is defined then 32 bit memory >> mapped access will be used to read/write the uart registers. >> >> This is especially useful for SoC devices that implement 16550 >> compatible uarts but that have peripheral access width constraints. >> >> Signed-off-by: Dave Aldridge <fovs...@gmail.com> > ... > >> --- a/drivers/serial/ns16550.c >> +++ b/drivers/serial/ns16550.c >> @@ -19,6 +19,12 @@ >> #ifdef CONFIG_SYS_NS16550_PORT_MAPPED >> #define serial_out(x,y) outb(x,(ulong)y) >> #define serial_in(y) inb((ulong)y) >> +#elif defined(CONFIG_SYS_NS16550_MEM32) && (CONFIG_SYS_NS16550_REG_SIZE > 0) >> +#define serial_out(x,y) out_be32(y,x) >> +#define serial_in(y) in_be32(y) >> +#elif defined(CONFIG_SYS_NS16550_MEM32) && (CONFIG_SYS_NS16550_REG_SIZE < 0) >> +#define serial_out(x,y) out_le32(y,x) >> +#define serial_in(y) in_le32(y) > > Sorry for the dumb question, but in which way is REG_SIZE > 0 or > REG_SIZE < 0 connected to the endianess of the target system? > > My understanding is that this only defines how byte wide registers > need to be padded, i. e. wether they are connected to the highest or > to the lowest byte lane. THis has nothing to do with the endianess of > the system, and it appears wrong to me, to imply such a relation here. > > Detlev, what do you think?
I _think_ that if we are concerned with the question of where a one-byte entity is placed in relation to its embracing 32-bit unit, then this is the definiton of endianness, right? Actually the endianness of the UART, and this is exactly what the interpretation of the sign of the REG_SIZE macro is. So if the patch works for Dave, he gets my Acked-by: Detlev Zundel <d...@denx.de> on the latter version. Cheers Detlev -- The Buddha, the Godhead, resides quite as comfortably in the circuits of a digital computer or the gears of a cycle transmission as he does at the top of a mountain or in the petals of a flower. To think otherwise is to demean the Buddha - which is to demean oneself. -- Robert M. Pirsig -- DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany Phone: (+49)-8142-66989-40 Fax: (+49)-8142-66989-80 Email: d...@denx.de _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
