Hi Wolfgang On 07/09/11 22:22, Wolfgang Denk wrote: > 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? >
No such thing as a dumb question. It is my understanding from the way that the REG_SIZE macro is currently being used in the driver that the endianess of the uart can be inferred in this way. >> #else >> #define serial_out(x,y) writeb(x,y) >> #define serial_in(y) readb(y) >> diff --git a/include/ns16550.h b/include/ns16550.h >> index 9ea81e9..d4ffac9 100644 >> --- a/include/ns16550.h >> +++ b/include/ns16550.h >> @@ -23,6 +23,8 @@ >> >> #if !defined(CONFIG_SYS_NS16550_REG_SIZE) || (CONFIG_SYS_NS16550_REG_SIZE >> == 0) >> #error "Please define NS16550 registers size." >> +#elif defined(CONFIG_SYS_NS16550_MEM32) >> +#define UART_REG(x) unsigned int x; > > I think you should rather use an explicit 32 bit data type here; > "int" may be 64 bits on some systems. > > Best regards, > > Wolfgang Denk > Cheers Dave _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
