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Date:   Wed, 8 Jun 2022 14:14:37 -0500
From:   Bjorn Helgaas <helgaas@kernel.org>
To:     Bharat Kumar Gogada <bharat.kumar.gogada@xilinx.com>
Cc:     linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org,
        devicetree@vger.kernel.org, lorenzo.pieralisi@arm.com,
        bhelgaas@google.com, michals@xilinx.com, robh@kernel.org
Subject: Re: [PATCH v4 2/2] PCI: xilinx-cpm: Add support for Versal CPM5 Root
 Port
Message-ID: <20220608191437.GA411770@bhelgaas>
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In-Reply-To: <20220608164046.3474-3-bharat.kumar.gogada@xilinx.com>
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On Wed, Jun 08, 2022 at 10:10:46PM +0530, Bharat Kumar Gogada wrote:
> Xilinx Versal Premium series has CPM5 block which supports Root Port
> functioning at Gen5 speed.
> 
> Xilinx Versal CPM5 has few changes with existing CPM block.
> - CPM5 has dedicated register space for control and status registers.
> - CPM5 legacy interrupt handling needs additional register bit
>   to enable and handle legacy interrupts.
> 
> Signed-off-by: Bharat Kumar Gogada <bharat.kumar.gogada@xilinx.com>
> ---
>  drivers/pci/controller/pcie-xilinx-cpm.c | 33 +++++++++++++++++++++++-
>  1 file changed, 32 insertions(+), 1 deletion(-)

Per MAINTAINERS, xilinx-cpm lacks a maintainer.  Can we get one?

> diff --git a/drivers/pci/controller/pcie-xilinx-cpm.c b/drivers/pci/controller/pcie-xilinx-cpm.c
> index c7cd44ed4dfc..a3b04083b6b3 100644
> --- a/drivers/pci/controller/pcie-xilinx-cpm.c
> +++ b/drivers/pci/controller/pcie-xilinx-cpm.c
> @@ -35,6 +35,10 @@
>  #define XILINX_CPM_PCIE_MISC_IR_ENABLE	0x00000348
>  #define XILINX_CPM_PCIE_MISC_IR_LOCAL	BIT(1)
>  
> +#define XILINX_CPM_PCIE_IR_STATUS       0x000002A0
> +#define XILINX_CPM_PCIE_IR_ENABLE       0x000002A8
> +#define XILINX_CPM_PCIE_IR_LOCAL        BIT(0)
> +
>  /* Interrupt registers definitions */
>  #define XILINX_CPM_PCIE_INTR_LINK_DOWN		0
>  #define XILINX_CPM_PCIE_INTR_HOT_RESET		3
> @@ -109,6 +113,7 @@
>   * @intx_irq: legacy interrupt number
>   * @irq: Error interrupt number
>   * @lock: lock protecting shared register access
> + * @is_cpm5: value to check cpm version

s/cpm version/CPM version/ to match commit log usage.

> +	port->is_cpm5 = of_device_is_compatible(dev->of_node,
> +						"xlnx,versal-cpm5-host");

One use of of_device_is_compatible() is OK, I guess, but
of_device_get_match_data() is a better pattern if we ever need more.

I would lean toward of_device_get_match_data() even here, just to
reduce the number of ways to identify device-specific things across
drivers.

Bjorn