Hi Wolfgang, On Fri, Apr 1, 2011 at 9:55 PM, Wolfgang Denk <w...@denx.de> wrote: > Dear Lei Wen, > > In message <AANLkTinqAyDx7=61FMgPdCg3ULt9nk93jF-y0Sdi=5...@mail.gmail.com> > you wrote: >> >> >> I think my code also could handle this. They only could set the >> >> CONFIG_SYS_NS16550_REG_SIZE =A0to be 1 >> >> and CONFIG_SYS_NS16550_MAX_REG_SIZE to be 4. Then >> >> the other bits is untouched by this driver. >> > >> > I don't think so. You still use just a single writel() call then. =A0To >> > leave the other bits untouched, you would have to perform a readl() >> > first, then insert one data byte, and then write it back. =A0Your patch >> > does not do that. >> >> My original patch is like below, so where it call writel?... >> +#elif (CONFIG_SYS_NS16550_REG_SIZE == 1) || (CONFIG_SYS_NS16550_REG_SIZE == >> -1) >> +#ifdef CONFIG_SYS_NS16550_PORT_MAPPED >> +#define serial_out(x, y) outb(x, y) >> +#define serial_in(y) inb(y) >> +#else >> +#define serial_out(x, y) writeb(x, y) >> +#define serial_in(y) readb(y) > > If you use writeb() [as the current driver would do as well}, then how > do you expect to set this bit 8 (which is in the next byte) to 0 as > you claim you have to?
As I explain, if set CONFIG_SYS_NS16550_REG_SIZE to 4, and set CONFIG_SYS_NS16550_MAX_REG_SIZE also to 4, then the serial_out becomes writel. :) +#if (CONFIG_SYS_NS16550_REG_SIZE == 4) || (CONFIG_SYS_NS16550_REG_SIZE == -4) +#ifdef CONFIG_SYS_NS16550_PORT_MAPPED +#define serial_out(x, y) outl(x, y) +#define serial_in(y) inl(y) +#else +#define serial_out(x, y) writel(x, y) +#define serial_in(y) readl(y) +#endif Best regards, Lei _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
