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From: swarren@wwwdotorg•org (Stephen Warren)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH v2 07/10] ARM: tegra: pcie: Add device tree support
Date: Tue, 19 Jun 2012 10:40:39 -0600	[thread overview]
Message-ID: <4FE0AB87.9030007@wwwdotorg.org> (raw)
In-Reply-To: <20120619133001.GB24138@avionic-0098.mockup.avionic-design.de>

On 06/19/2012 07:30 AM, Thierry Reding wrote:
> On Fri, Jun 15, 2012 at 08:12:36AM +0200, Thierry Reding wrote:
>> On Thu, Jun 14, 2012 at 01:50:56PM -0600, Stephen Warren wrote:
...
>>> To me, working back from address to ID then using the ID to calculate
>>> some other addresses seems far more icky than just calculating all the
>>> addresses based off of one ID. But, I suppose this doesn't make a huge
>>> practical difference.
>>
>> This really depends on the device vs. no device decision below. If we can
>> make it work without needing an extra device for it, then using the index
>> is certainly better. However, if we instantiate devices from the DT, then
>> we have the address anyway and adding the index as a property would be
>> redundant and error prone (what happens if somebody sets the index of the
>> port at address 0x80000000 to 2?).
> 
> An additional problem with this is that we'd have to add the following
> to the pcie-controller node:
> 
> 	#address-cells = <1>;
> 	#size-cells = <0>;
> 
> This will conflict with the "ranges" property, because suddenly we can
> no longer map the regions properly. Maybe Mitch can comment on whether
> this is possible or not?
> 
> To make it clearer what I'm talking about, here's the DT snippet again
> (with the compatible property removed from the pci@ nodes because they
> are no longer probed by a driver, the "simple-bus" removed from the
> pcie-controller node's compatible property removed and its #address-
> and #size-cells properties adjusted as described above).
> 
> 	pcie-controller {
> 		compatible = "nvidia,tegra20-pcie";
> 		reg = <0x80003000 0x00000800   /* PADS registers */
> 		       0x80003800 0x00000200   /* AFI registers */
> 		       0x80004000 0x00100000   /* configuration space */
> 		       0x80104000 0x00100000>; /* extended configuration space */
> 		interrupts = <0 98 0x04   /* controller interrupt */
> 			      0 99 0x04>; /* MSI interrupt */
> 		status = "disabled";
> 
> 		ranges = <0x80000000 0x80000000 0x00002000   /* 2 root ports */
> 			  0x80400000 0x80400000 0x00010000   /* downstream I/O */
> 			  0x90000000 0x90000000 0x10000000   /* non-prefetchable memory */
> 			  0xa0000000 0xa0000000 0x10000000>; /* prefetchable memory */
> 
> 		#address-cells = <1>;
> 		#size-cells = <0>;
> 
> 		pci at 0 {
> 			reg = <2>;
> 			status = "disabled";
> 
> 			#address-cells = <3>;
> 			#size-cells = <2>;
> 
> 			ranges = <0x81000000 0 0 0x80400000 0 0x00008000   /* I/O */
> 				  0x82000000 0 0 0x90000000 0 0x08000000   /* non-prefetchable memory */
> 				  0xc2000000 0 0 0xa0000000 0 0x08000000>; /* prefetchable memory */
> 
> 			nvidia,ctrl-offset = <0x110>;
> 			nvidia,num-lanes = <2>;
> 		};
> 
> 		pci at 1 {
> 			reg = <1>;
> 			status = "disabled";
> 
> 			#address-cells = <3>;
> 			#size-cells = <2>;
> 
> 			ranges = <0x81000000 0 0 0x80408000 0 0x00008000   /* I/O */
> 				  0x82000000 0 0 0x98000000 0 0x08000000   /* non-prefetchable memory */
> 				  0xc2000000 0 0 0xa8000000 0 0x08000000>; /* prefetchable memory */
> 
> 			nvidia,ctrl-offset = <0x118>;
> 			nvidia,num-lanes = <2>;
> 		};
> 	};
> 
> AIUI none of the ranges properties are valid anymore, because the bus
> represented by pcie-controller no longer reflects the truth, namely that
> it translates the CPU address space to the PCI address space.

Yes, I imagine that's a show-stopper for this approach.

  reply	other threads:[~2012-06-19 16:40 UTC|newest]

Thread overview: 96+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-06-11 15:05 [PATCH v2 00/10] ARM: tegra: Add PCIe device tree support Thierry Reding
2012-06-11 15:05 ` [PATCH v2 01/10] PCI: Keep pci_fixup_irqs() around after init Thierry Reding
2012-06-11 15:05 ` [PATCH v2 02/10] ARM: pci: Keep pci_common_init() " Thierry Reding
2012-06-11 15:05 ` [PATCH v2 03/10] ARM: pci: Allow passing per-controller private data Thierry Reding
2012-06-11 15:05 ` [PATCH v2 04/10] ARM: tegra: Move tegra_pcie_xclk_clamp() to PMC Thierry Reding
2012-06-11 15:05 ` [PATCH v2 05/10] ARM: tegra: Rewrite PCIe support as a driver Thierry Reding
2012-06-11 21:09   ` Stephen Warren
2012-06-12  6:41     ` Thierry Reding
2012-06-12  7:24       ` Thierry Reding
2012-06-12 16:00         ` Stephen Warren
2012-06-13  8:12           ` Thierry Reding
2012-06-11 21:22   ` Stephen Warren
2012-06-12  4:59     ` Thierry Reding
2012-06-11 15:05 ` [PATCH v2 06/10] ARM: tegra: pcie: Add MSI support Thierry Reding
2012-06-11 21:19   ` Stephen Warren
2012-06-12  5:07     ` Thierry Reding
2012-06-12  5:33       ` Stephen Warren
2012-06-12  5:41         ` Thierry Reding
2012-06-12  6:10       ` Thierry Reding
2012-06-12 15:40         ` Stephen Warren
2012-06-12 17:23           ` Thierry Reding
2012-06-11 15:05 ` [PATCH v2 07/10] ARM: tegra: pcie: Add device tree support Thierry Reding
2012-06-11 21:33   ` Stephen Warren
2012-06-12  6:21     ` Thierry Reding
2012-06-12 15:44       ` Stephen Warren
2012-06-12 17:20         ` Thierry Reding
2012-06-12 19:10           ` Mitch Bradley
2012-06-12 19:46             ` Stephen Warren
2012-06-12 19:52               ` Mitch Bradley
2012-06-13  5:54                 ` Thierry Reding
2012-06-13  7:04                   ` Mitch Bradley
2012-06-12 20:15           ` Stephen Warren
2012-06-12 21:11             ` Mitch Bradley
2012-06-13  6:45               ` Thierry Reding
2012-06-13  7:28                 ` Mitch Bradley
2012-06-13  7:52                   ` Thierry Reding
2012-06-13  8:05                     ` Mitch Bradley
2012-06-13  8:19                       ` Thierry Reding
2012-06-13  8:36                         ` Mitch Bradley
2012-06-13  8:42                           ` Thierry Reding
2012-06-14  9:19                           ` Thierry Reding
2012-06-14 18:30                             ` Stephen Warren
2012-06-14 19:29                               ` Thierry Reding
2012-06-14 19:50                                 ` Stephen Warren
2012-06-15  6:12                                   ` Thierry Reding
2012-06-19 13:30                                     ` Thierry Reding
2012-06-19 16:40                                       ` Stephen Warren [this message]
2012-06-19 21:31                                       ` Mitch Bradley
2012-06-20 16:32                                         ` Stephen Warren
2012-06-20 17:41                                           ` Mitch Bradley
2012-06-20 17:47                                             ` Stephen Warren
2012-06-20 19:57                                         ` Arnd Bergmann
2012-06-20 20:19                                           ` Mitch Bradley
2012-06-21  6:47                                         ` Thierry Reding
2012-06-22 10:18                                           ` Bjorn Helgaas
2012-06-22 11:00                                             ` Thierry Reding
2012-06-22 11:46                                               ` Bjorn Helgaas
2012-06-22 12:43                                                 ` Thierry Reding
2012-06-22 13:03                                                   ` Arnd Bergmann
2012-06-22 16:49                                                     ` Bjorn Helgaas
2012-06-22 16:53                                                       ` Arnd Bergmann
2012-06-22 17:13                                                         ` Bjorn Helgaas
2012-06-22 21:08                                                           ` Arnd Bergmann
2012-06-22 17:14                                                         ` Arnd Bergmann
2012-06-22 17:00                                               ` Stephen Warren
2012-06-22 17:28                                                 ` Stephen Warren
2012-06-23 21:35                                                   ` Bjorn Helgaas
2012-06-25  6:34                                                   ` Thierry Reding
2012-06-26 17:22                                                     ` Stephen Warren
2012-06-27  6:19                                                       ` Thierry Reding
2012-06-22 16:20                                           ` Stephen Warren
2012-06-22 17:09                                           ` Mitch Bradley
2012-06-22 11:04                                         ` Thierry Reding
2012-06-22 13:22                                           ` Thierry Reding
2012-06-22 13:48                                             ` Arnd Bergmann
2012-06-22 14:02                                               ` Thierry Reding
2012-06-22 16:40                                                 ` Arnd Bergmann
2012-06-13 20:21                     ` Arnd Bergmann
2012-06-14  8:37                       ` Thierry Reding
2012-06-14 10:25                         ` Arnd Bergmann
2012-06-14 10:31                           ` Thierry Reding
2012-06-14 11:06                             ` Arnd Bergmann
2012-06-14 11:58                               ` Thierry Reding
2012-06-13  6:34             ` Thierry Reding
2012-06-13 16:20               ` Stephen Warren
2012-06-13 17:03               ` Stephen Warren
2012-06-11 15:05 ` [PATCH v2 08/10] ARM: tegra: harmony: Initialize regulators from DT Thierry Reding
2012-06-11 21:36   ` Stephen Warren
2012-06-12  6:13     ` Thierry Reding
2012-06-21 20:17   ` Stephen Warren
2012-06-22  6:06     ` Thierry Reding
2012-06-11 15:05 ` [PATCH v2 09/10] ARM: tegra: harmony: Initialize PCIe " Thierry Reding
2012-06-11 21:41   ` Stephen Warren
2012-06-12  5:48     ` Thierry Reding
2012-06-12 15:38       ` Stephen Warren
2012-06-11 15:05 ` [PATCH v2 10/10] ARM: tegra: trimslice: " Thierry Reding

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