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From: zourongrong@huawei•com (Rongrong Zou)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH v1 3/3] ARM64 LPC: update binding doc
Date: Tue, 5 Jan 2016 19:59:49 +0800	[thread overview]
Message-ID: <568BB035.1050801@huawei.com> (raw)
In-Reply-To: <6384244.Uhpjfgly6O@wuerfel>

? 2016/1/5 0:34, Arnd Bergmann ??:
> On Tuesday 05 January 2016 00:04:19 Rongrong Zou wrote:
>> ? 2016/1/4 19:13, Arnd Bergmann ??:
>>> On Sunday 03 January 2016 20:24:14 Rongrong Zou wrote:
>>>> ? 2015/12/31 23:00, Rongrong Zou ??:
>>>> */
>>>>       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 at 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.
>>
>> Ranges property can set empty, but this means 1:1 translation. the I/O
>> port range is translated to MMIO address 0x00000001 00000000 to
>> 0x00000001 00000004, it looks wrong else. I wonder if anyone get legacy
>> I/O port resource from dts.
>
> As I said, nothing should really require the ranges property here, unless
> you have a valid IORESOURCE_MEM translation. The code that requires
> the ranges to be present is wrong.
>

I think the openfirmware(DT) do not support for those unmapped I/O ports, because I
must get resource by calling of_address_to_resource(), which have to call
pci_address_to_pio() when resource type is IORESOURCE_IO. I'm sorry I have no
better idea for this now. Maybe liviu can give me some opinions.

/**
  * of_address_to_resource - Translate device tree address and return as resource
  *
  * Note that if your address is a PIO address, the conversion will fail if
  * the physical address can't be internally converted to an IO token with
  * pci_address_to_pio(), that is because it's either called to early or it
  * can't be matched to any host bridge IO space
  */
int of_address_to_resource(struct device_node *dev, int index,
			   struct resource *r)

>> For ipmi driver, I can get I/O port resource by DMI rather than dts.
>
> No, the ipmi driver uses the resource that belongs to the platform
> device already, you can't rely on DMI data to be present there.

Ipmi has a lot of way to be discovered(ACPI, DMI, hardcoded, hot-add,
openfirmware and a few other), I think we just use one of them, not all of them.
It depend on vendor's hardware solution actually.


>
> 	Arnd
>
> .
>

Thanks,

Rongrong

  reply	other threads:[~2016-01-05 11:59 UTC|newest]

Thread overview: 32+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <1451396032-23708-1-git-send-email-zourongrong@gmail.com>
     [not found] ` <1899302.RWIn6Bg3Dr@wuerfel>
     [not found]   ` <568537C3.3060902@huawei.com>
     [not found]     ` <17750582.ajK78gYOFz@wuerfel>
     [not found]       ` <CABTftiT1+AmrNjiAie-T6on-oWA4Zz73+Tj2pQrixMT3o475uw@mail.gmail.com>
2016-01-03 12:24         ` [PATCH v1 3/3] ARM64 LPC: update binding doc Rongrong Zou
2016-01-04 11:13           ` Arnd Bergmann
2016-01-04 16:04             ` Rongrong Zou
2016-01-04 16:34               ` Arnd Bergmann
2016-01-05 11:59                 ` Rongrong Zou [this message]
2016-01-05 12:19                   ` Arnd Bergmann
2016-01-06 13:36                     ` Rongrong Zou
2016-01-07  3:37                       ` Rongrong Zou
2016-01-10  9:29                     ` Rolland Chau
2016-01-10 13:38                       ` Rongrong Zou
2016-01-11 16:14             ` liviu.dudau at arm.com
2016-01-12  2:39               ` Rongrong Zou
2016-01-12  9:07                 ` liviu.dudau at arm.com
2016-01-12  9:25                   ` Rongrong Zou
2016-01-12 10:14                     ` liviu.dudau at arm.com
2016-01-12 11:05                       ` Rongrong Zou
2016-01-12 11:27                         ` liviu.dudau at arm.com
2016-01-12 11:56                           ` Rongrong Zou
2016-01-12 15:13                             ` liviu.dudau at arm.com
2016-01-12 22:52                               ` Arnd Bergmann
2016-01-13  5:53                                 ` Benjamin Herrenschmidt
2016-01-13  6:34                                   ` Rongrong Zou
2016-01-13  9:26                                     ` Arnd Bergmann
2016-01-13 10:10                                 ` liviu.dudau at arm.com
2016-01-13 10:18                                   ` Arnd Bergmann
2016-01-13 10:32                                     ` liviu.dudau at arm.com
2016-01-12 22:54                       ` Arnd Bergmann
2016-01-13 10:09                         ` liviu.dudau at arm.com
2016-01-13 10:29                           ` Arnd Bergmann
2016-01-13 11:06                           ` Rongrong Zou
2016-01-13 11:25                             ` liviu.dudau at arm.com
     [not found] ` <1628979.qkJQGmVH0I@wuerfel>
     [not found]   ` <5683A3B4.7040005@huawei.com>
     [not found]     ` <23432380.Bk9bdl2Z0r@wuerfel>
     [not found]       ` <20160104101124.GA1616@arm.com>
2016-01-04 10:27         ` [PATCH v1 1/3] ARM64 LPC: indirect ISA PORT IO introduced Rongrong Zou

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