On Tue, Jan 12, 2016 at 05:25:56PM +0800, Rongrong Zou wrote: > 在 2016/1/12 17:07, liviu.dudau@xxxxxxx 写道: > >On Tue, Jan 12, 2016 at 10:39:36AM +0800, Rongrong Zou wrote: > >>On 2016/1/12 0:14, liviu.dudau@xxxxxxx wrote: > >>>On Mon, Jan 04, 2016 at 12:13:05PM +0100, Arnd Bergmann wrote: > >>>>On Sunday 03 January 2016 20:24:14 Rongrong Zou wrote: > >>>>>在 2015/12/31 23:00, Rongrong Zou 写道: > >>>>>>2015-12-31 22:40 GMT+08:00 Arnd Bergmann <arnd@xxxxxxxx <mailto:arnd@xxxxxxxx>>: > >>>>>> > 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: > >>>>>> > > >>>>>> > 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"); > >>>>>* } > >>>> > >>>>Looks good. It would be nicer to match on device_type than on name, > >>>>but this is ancient code and it's probably best not to touch it > >>>>so we don't accidentally break some old SPARC or PPC system. > >>>> > >>>>>*/ > >>>>> 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>; > >>>>>}; > >>>>> > >>>> > >>>>This looks wrong: the property above says that the I/O port range is > >>>>translated to MMIO address 0x00000000 to 0x00010000, which is not > >>>>true on your hardware. I think this needs to be changed in the code > >>>>so the ranges property is not required for I/O ports. > >>>> > >>>>>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; > >>>>> } > >>>> > >>>>I don't like having a special case based on the address here, > >>>>the same kind of hack might be needed for PCI I/O spaces in > >>>>hardware that uses an indirect method like your LPC bus > >>>>does, and the code above will not work on any LPC implementation > >>>>that correctly multiplexes its I/O ports with the first PCI domain. > >>>> > >>>>I think it would be better to avoid translating the port into > >>>>a physical address to start with just to translate it back into > >>>>a port number, what we need instead is the offset between the > >>>>bus specific port number and the linux port number. I've added > >>>>Liviu to Cc, he wrote this code originally and may have some idea > >>>>of how we could do that. > >>> > >>>Hi, > >> > >>Hi Liviu, > >> > >>Thanks for reviewing this. > >> > >>> > >>>Getting back to work after a longer holiday, my brain might not be running > >>>at full speed here, so I'm trying to clarify things a bit here. > >>> > >>>It looks to me like Rongrong is trying to trap the inb()/outb() calls that he > >>>added to arm64 by patch 1/3 and redirect those operations to the memory > >>>mapped LPC driver. I think the whole redirection and registration of inb/outb > >>>ops can be made cleaner, so that the general concept resembles the DMA ops > >>>registration? (I have this mental picture that what Rongrong is trying to do > >>>is similar to what a DMA engine does, except this is slowing down things to > >>>byte level). If that is done properly in the parent node, then we should not > >>>care what the PCIBIOS_MIN_IO value is as the inb()/outb() calls will always > >>>go through the redirection for the children. > >>> > >>>As for the ranges property: does he wants the ipmi-bt driver to see in the > >>>reg property the legacy ISA I/O ports values or the CPU addresses? If the former, > >>>then I agree that the range property should not be required, but also the > >>>reg values need to be changed (drop the top bit). If the later, then the > >>>ranges property is required to do the proper translation. > >> > >>The former, thanks. > >> > >>> > >>>Rongrong, removing the ranges property and with a reg = <0xe4 0x4> property > >>>in the ipmi-bt node, what IO_RESOURCE type resources do you get back from > >>>the of_address_to_resource() translation? > >> > >>I want to get IORESOURCE_IO type resource, but if the parent node drop the > >>"rangs" property, the of_address_to_resource() translation will return with -EINVAL. > > > >Have you tracked what part of the code is sensitive to the presence of "ranges" > >property? Does of_get_address() call returns the IO_RESOURCE flag set without "ranges"? > > > > > Yes, IO_RESOURCE flag can be get without "ranges". > I tracked the code, it is at of_translate_one(), Below is the calling infomation. > > of_address_to_resource-> __of_address_to_resource ->of_translate_address-> > __of_translate_address(dev, in_addr, "ranges")->of_translate_one() > > > static int of_translate_one(struct device_node *parent, struct of_bus *bus, > struct of_bus *pbus, __be32 *addr, > int na, int ns, int pna, const char *rprop) > { > const __be32 *ranges; > unsigned int rlen; > int rone; > u64 offset = OF_BAD_ADDR; > > ranges = of_get_property(parent, rprop, &rlen); > if (ranges == NULL && !of_empty_ranges_quirk(parent)) { > pr_debug("OF: no ranges; cannot translate\n"); > return 1; > } > ... > } OK, looking at of_translate_one() comments it looks like a missing "ranges" property is only accepted on PowerPC. I suggest you have an empty "ranges" property in your isa parent node, that will signal to the OF parsing code that the mapping is 1:1. Then have the IPMI node use the reg = <0x0 0xe4 4>; property values instead of reg = <0x1 0xe4 4>; Best regards, Liviu > > >Best regards, > >Liviu > > > >> > >>> > >>>Best regards, > >>>Liviu > >>> > >>> > >>>> > >>>> Arnd > >>>> > >>> > >>Regards, > >>Rongrong > >> > > > -- > Regards, > Rongrong > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@xxxxxxxxxxxxxxxxxxx > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel -- ==================== | I would like to | | fix the world, | | but they're not | | giving me the | \ source code! / --------------- ¯\_(ツ)_/¯ -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
