2016-05-17 14:48 GMT+02:00 Paul Burton <paul.bur...@imgtec.com>: > On Tue, May 17, 2016 at 06:11:22AM -0600, Simon Glass wrote: >> Hi Paul, >> >> On 16 May 2016 at 11:44, Paul Burton <paul.bur...@imgtec.com> wrote: >> > If the UART is to be accessed using I/O port accessors (inb & outb) then >> > using map_physmem doesn't make sense, since it operates in a different >> > memory space. Remove the call to map_physmem when >> > CONFIG_SYS_NS16550_PORT_MAPPED is defined, allowing I/O port addresses >> > to not be mangled by the incorrect mapping. >> > >> > Signed-off-by: Paul Burton <paul.bur...@imgtec.com> >> > --- >> > >> > Changes in v2: >> > - New patch, part of a simplified approach tackling only a single Malta >> > UART. >> > >> > drivers/serial/ns16550.c | 8 ++++++++ >> > 1 file changed, 8 insertions(+) >> > >> > diff --git a/drivers/serial/ns16550.c b/drivers/serial/ns16550.c >> > index 28da9dd..e58e6aa 100644 >> > --- a/drivers/serial/ns16550.c >> > +++ b/drivers/serial/ns16550.c >> > @@ -100,7 +100,11 @@ static void ns16550_writeb(NS16550_t port, int >> > offset, int value) >> > unsigned char *addr; >> > >> > offset *= 1 << plat->reg_shift; >> > +#ifdef CONFIG_SYS_NS16550_PORT_MAPPED >> > + addr = (unsigned char *)plat->base + offset; >> > +#else >> > addr = map_physmem(plat->base, 0, MAP_NOCACHE) + offset; >> > +#endif >> >> Please don't add CONFIG #ifdefs in these functions. Perhaps it needs >> to be another parameter? Possibly a flag. But with driver-model we >> need to be able to support both options in the core code. > > Hi Simon, > > Are you sure systems rely on using I/O ports with map_physmem? The only > other systems that define CONFIG_SYS_NS16550_PORT_MAPPED are x86 ones, > in include/configs/x86-common.h, and so far as I can tell they don't use > device model which suggests this code has simply been untested before. I > don't see why you would use map_physmem on an I/O port address that is > then going to be passed to inb/outb & I think the code here is simply > wrong to do so.
the current code looks wrong. serial_in_shift() is expanded to inb() in case of CONFIG_SYS_NS16550_PORT_MAPPED and to in_le32()/in_be32()/readl()/readb() otherwise. Only in the latter case a map_physmem() is required and should be done in serial_in_shift() itself or preferrably only once in ns16550_serial_ofdata_to_platdata(). I think the correct approach would be the following: --- a/drivers/serial/ns16550.c +++ b/drivers/serial/ns16550.c @@ -100,7 +100,8 @@ static void ns16550_writeb(NS16550_t port, int offset, int value) unsigned char *addr; offset *= 1 << plat->reg_shift; - addr = map_physmem(plat->base, 0, MAP_NOCACHE) + offset; + addr = plat->base + offset; + /* * As far as we know it doesn't make sense to support selection of * these options at run-time, so use the existing CONFIG options. @@ -114,7 +115,7 @@ static int ns16550_readb(NS16550_t port, int offset) unsigned char *addr; offset *= 1 << plat->reg_shift; - addr = map_physmem(plat->base, 0, MAP_NOCACHE) + offset; + addr = plat->base + offset; return serial_in_shift(addr + plat->reg_offset, plat->reg_shift); } @@ -400,7 +401,12 @@ int ns16550_serial_ofdata_to_platdata(struct udevice *dev) if (addr == FDT_ADDR_T_NONE) return -EINVAL; +#ifdef CONFIG_SYS_NS16550_PORT_MAPPED plat->base = addr; +#else + plat->base = map_physmem(addr, 0, MAP_NOCACHE); +#endif + plat->reg_offset = fdtdec_get_int(gd->fdt_blob, dev->of_offset, "reg-offset", 0); plat->reg_shift = fdtdec_get_int(gd->fdt_blob, dev->of_offset, -- - Daniel _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot