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"? Best regards, Liviu > > > > >Best regards, > >Liviu > > > > > >> > >> Arnd > >> > > > Regards, > Rongrong > -- ==================== | 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
