Re: [PATCH v1 3/3] ARM64 LPC: update binding doc

Rongrong Zou
2016-01-03T12:28:31Z

在 2015/12/31 23:00, Rongrong Zou 写道:
>
>
> 2015-12-31 22:40 GMT+08:00 Arnd Bergmann <arnd@arndb.de <mailto:arnd@arndb.de>>:
> >
> > On Thursday 31 December 2015 22:12:19 Rongrong Zou wrote:
> > > 在 2015/12/30 17:06, Arnd Bergmann 写道:
> > > > On Tuesday 29 December 2015 21:33:52 Rongrong Zou wrote:
> > > >> +Example:
> > > >> +
> > > >> + lpc_0: lpc@a01b0000 {
> > > >> + #address-cells = <1>;
> > > >> + #size-cells = <1>;
> > > >> + compatible = "low-pin-count";
> > > >> + reg = <0x0 0xa01b0000 0x0 0x10000>;
> > > >> + };
> > > >
> > > > One more thought: please try to stick as closely as possible to the existing
> > > > ISA binding that is documented at
> > > >
> > > > http://www.firmware.org/1275/bindings/isa/isa0_4d.ps
> > > From the specification, I think I should use 2 32bit integer to describe the isa addr in dts.
> > > >
> > > > In particular, this should cover the possibility of describing both memory
> > > > and I/O spaces in child devices.
> > > >
> > >
> > > I found below config in powerpc dts "arch/powerpc/boot/dts/mpc8544ds.dts"
> > >
> > > isa@1e {
> > > device_type = "isa";
> > > #interrupt-cells = <2>;
> > > #size-cells = <1>;
> > > #address-cells = <2>;
> > > reg = <0xf000 0x0 0x0 0x0 0x0>;
> > > ranges = <0x1 0x0 0x1000000 0x0 0x0
> > > 0x1000>;
> > > interrupt-parent = <&i8259>;
> > >
> > >
> > >
> > > rtc@70 {
> > > compatible = "pnpPNP,b00";
> > > reg = <0x1 0x70 0x2>;
> > > };
> > > the isa space in child-node: reg = <0x1 0x70 0x2>;
> > > 0x1 means IO space, 70 means addr, 0x2 is size.
> > > but when i config the following in dts, the ipmi_0 node can't be probed,
> > > I think there may be some problems.
> > >
> > > lpc_0: lpc@a01b0000 {
> > > compatible = "low-pin-count";
> > > device_type = "isa";
> > > #address-cells = <2>;
> > > #size-cells = <1>;
> > > reg = <0x0 0xa01b0000 0x0 0x10000>;
> > >
> > > ipmi_0:ipmi@000000e4{
> > > device_type = "ipmi";
> > > compatible = "ipmi-bt";
> > > reg = <0x1 0x000000e4 0x4>;
> > > };
> >
> > The DT sample above looks good in principle. I believe what you are missing
> > here is code in your driver to scan the child nodes to create the platform
> > devices. of_bus_isa_translate() should work with your definition here
> > and create the correct IORESOURCE_IO resources. You don't have any MMIO
> > resources, so the absence of a ranges property is ok. Maybe all you
> > are missing is a call to of_platform_populate() or of_platform_bus_probe()?
> >
>
> You are right. thanks, i'll try on test board . if i get the correct result , the new patch
> will be sent later. By the way, it's my another email account use when i at home.

I tried, and there need some additional changes.

isa@a01b0000 {

/*the node name should start with "isa", because of below definition
* static int of_bus_isa_match(struct device_node *np)
* {
* return !strcmp(np->name, "isa");
* }
*/
compatible = "low-pin-count";
device_type = "isa";
#address-cells = <2>;
#size-cells = <1>;
reg = <0x0 0xa01b0000 0x0 0x10000>;
ranges = <0x1 0x0 0x0 0x0 0x1000>;
/*
* ranges is required, then i can get the IORESOURCE_IO <0xe4,4> from "reg = <0x1, 0x000000e4, 4>".
*
*/
ipmi_0:ipmi@000000e4{
device_type = "ipmi";
compatible = "ipmi-bt";
reg = <0x1 0x000000e4 0x4>;
};

drivers\of\address.c
static int __of_address_to_resource(struct device_node *dev,
const __be32 *addrp, u64 size, unsigned int flags,
const char *name, struct resource *r)
{
u64 taddr;

if ((flags & (IORESOURCE_IO | IORESOURCE_MEM)) == 0)
return -EINVAL;
taddr = of_translate_address(dev, addrp);
if (taddr == OF_BAD_ADDR)
return -EINVAL;
memset(r, 0, sizeof(struct resource));
if (flags & IORESOURCE_IO) {
unsigned long port;

/*****************************************************************/
/*legacy port(< 0x1000) is reserved, and need no translation here*/
/*****************************************************************/
if(taddr + size < PCIBIOS_MIN_IO){
r->start = taddr;
r->end = taddr + size - 1;
}

else{
port = pci_address_to_pio(taddr);
if (port == (unsigned long)-1)
return -EINVAL;
r->start = port;
r->end = port + size - 1;
}
} else {
r->start = taddr;
r->end = taddr + size - 1;
}
r->flags = flags;
r->name = name ? name : dev->full_name;

return 0;
}

>
> > Arnd