Hi Daniel, On 17 May 2016 at 09:51, Daniel Schwierzeck <daniel.schwierz...@gmail.com> wrote: > > 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:
This is better I think. But how about adding a device tree binding to select I/O access? In principle each device might have its own settings. > > --- 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 Regards, Simon _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
