From: Mason <slash.tmp@free.fr>
To: Marc Zyngier <marc.zyngier@arm.com>
Cc: Marc Gonzalez <marc_gonzalez@sigmadesigns.com>,
Bjorn Helgaas <helgaas@kernel.org>,
linux-pci <linux-pci@vger.kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
Robin Murphy <robin.murphy@arm.com>,
Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
Liviu Dudau <liviu.dudau@arm.com>,
David Laight <david.laight@aculab.com>,
Linux ARM <linux-arm-kernel@lists.infradead.org>,
Thibaud Cornic <thibaud_cornic@sigmadesigns.com>,
Phuong Nguyen <phuong_nguyen@sigmadesigns.com>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v4 2/2] PCI: Add tango PCIe host bridge support
Date: Thu, 25 May 2017 14:00:31 +0200 [thread overview]
Message-ID: <57673076-4fbd-92ab-453c-3d77fd65407f@free.fr> (raw)
In-Reply-To: <62bb805a-abd6-9aca-3641-8037f42a3b95@arm.com>
On 25/05/2017 10:48, Marc Zyngier wrote:
> On 20/04/17 15:31, Marc Gonzalez wrote:
>
>> This driver is required to work around several hardware bugs in the
>> PCIe controller.
>>
>> NB: Revision 1 does not support legacy interrupts, or IO space.
>>
>> Signed-off-by: Marc Gonzalez <marc_gonzalez@sigmadesigns.com>
>> ---
>> Documentation/devicetree/bindings/pci/tango-pcie.txt | 32 ++++++++
>> drivers/pci/host/Kconfig | 8 ++
>> drivers/pci/host/Makefile | 1 +
>> drivers/pci/host/pcie-tango.c | 161 +++++++++++++++++++++++++++++++++++++++
>> include/linux/pci_ids.h | 2 +
>> 5 files changed, 204 insertions(+)
>>
>> diff --git a/Documentation/devicetree/bindings/pci/tango-pcie.txt b/Documentation/devicetree/bindings/pci/tango-pcie.txt
>> new file mode 100644
>> index 000000000000..3353b4e77309
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/pci/tango-pcie.txt
>> @@ -0,0 +1,32 @@
>> +Sigma Designs Tango PCIe controller
>> +
>> +Required properties:
>> +
>> +- compatible: "sigma,smp8759-pcie"
>> +- reg: address/size of PCI configuration space, address/size of register area
>> +- device_type: "pci"
>> +- #size-cells: <2>
>> +- #address-cells: <3>
>> +- #interrupt-cells: <1>
>
> What is the point of having an #interrupt-cells when this is *not* an
> interrupt controller (as it doesn't support legacy interrupts)?
My mistake.
Thanks for kindly pointing out that the #interrupt-cells property
is not needed when a controller doesn't support legacy interrupts.
If a controller does support legacy interrupts, then I see other
bindings define #interrupt-cells and interrupt-map.
Is interrupt-controller also required?
Is that redundant with msi-controller?
(Rev2 will support legacy interrupts.)
References for my own information:
http://elixir.free-electrons.com/linux/latest/source/Documentation/devicetree/bindings/pci/host-generic-pci.txt
http://elixir.free-electrons.com/linux/latest/source/Documentation/devicetree/bindings/pci/altera-pcie.txt
http://elinux.org/Device_Tree_Usage#Advanced_Interrupt_Mapping
> As mentioned earlier, this needs to be a separate patch to be reviewed
> by the Keepers of the Faith (aka the DT maintainers).
robh already acked v3 two months ago, but can split it up,
and CC the DT folks for v5.
>> +static int smp8759_init(struct tango_pcie *pcie, void __iomem *base)
>> +{
>> + pcie->mux = base + 0x48;
>> + pcie->msi_status = base + 0x80;
>> + pcie->msi_enable = base + 0xa0;
>> + pcie->msi_doorbell = 0xa0000000 + 0x2e07c;
>> +
>> + return tango_check_pcie_link(base + 0x74);
>
> Please have some defines for these magic values.
Typical driver do
#define MUX_OFFSET 0x48
and then access the register's value through
readl_relaxed(pcie->base + MUX_OFFSET);
I can't do that because the registers were shuffled around
between revision 1 and revision 2. Thus, instead of an
explicitly-named macro (MUX_OFFSET), I used an explicitly-
named field (pcie->mux) and access the register's value
through readl_relaxed(pcie->mux);
This is equivalent to providing the offset definitions in the
init functions, instead of at the top of the file.
Regards.
next prev parent reply other threads:[~2017-05-25 12:01 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-04-20 14:24 [PATCH v4 0/2] Tango PCIe controller support Marc Gonzalez
2017-04-20 14:28 ` [PATCH v4 1/2] PCI: Add tango MSI " Marc Gonzalez
2017-05-17 14:56 ` Marc Gonzalez
2017-05-23 17:03 ` Bjorn Helgaas
2017-05-23 17:54 ` Mason
2017-05-23 18:03 ` Robin Murphy
2017-05-23 19:15 ` Mason
2017-05-24 10:00 ` Robin Murphy
2017-05-24 10:22 ` Marc Zyngier
2017-05-31 14:18 ` Mason
2017-05-31 17:34 ` Bjorn Helgaas
2017-05-31 18:49 ` Mason
2017-05-31 19:00 ` Bjorn Helgaas
2017-05-31 19:12 ` Bjorn Helgaas
2017-05-31 19:27 ` Mason
2017-05-31 20:04 ` Bjorn Helgaas
2017-05-31 21:55 ` Mason
2017-05-25 8:37 ` Marc Zyngier
2017-05-31 7:32 ` Marc Gonzalez
2017-04-20 14:31 ` [PATCH v4 2/2] PCI: Add tango PCIe host bridge support Marc Gonzalez
2017-05-23 17:24 ` Bjorn Helgaas
2017-05-23 17:43 ` Mason
2017-05-23 18:35 ` Bjorn Helgaas
2017-05-23 19:29 ` Mason
2017-05-25 8:48 ` Marc Zyngier
2017-05-25 12:00 ` Mason [this message]
2017-05-25 12:23 ` Marc Zyngier
2017-05-25 12:41 ` Mason
2017-05-25 13:20 ` Marc Zyngier
2017-05-15 8:16 ` [PATCH v4 0/2] Tango PCIe controller support Marc Gonzalez
2017-05-23 17:17 ` Bjorn Helgaas
2017-05-23 18:07 ` Mason
2017-05-23 18:30 ` Bjorn Helgaas
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