Re: [PATCH v4 07/12] PCI: aardvark: Add PHY support

Rob Herring
2020-05-07T21:23:50Z

On Thu, 30 Apr 2020 10:06:20 +0200, =?UTF-8?q?Pali=20Roh=C3=A1r?= wrote:
> From: Marek Behún <marek.behun@nic.cz>
>
> With recent proposed changes for U-Boot it is possible that bootloader
> won't initialize the PHY for this controller (currently the PHY is
> initialized regardless whether PCI is used in U-Boot, but with these
> proposed changes the PHY is initialized only on request).
>
> Since the mvebu-a3700-comphy driver by Miquèl Raynal supports enabling
> PCIe PHY, and since Linux' functionality should be independent on what
> bootloader did, add code for enabling generic PHY if found in device OF
> node.
>
> The mvebu-a3700-comphy driver does PHY powering via SMC calls to ARM
> Trusted Firmware. The corresponding code in ARM Trusted Firmware skips
> one register write which U-Boot does not: step 7 ("Enable TX"), see [1].
> Instead ARM Trusted Firmware expects PCIe driver to do this step,
> probably because the register is in PCIe controller address space,
> instead of PHY address space. We therefore add this step into the
> advk_pcie_setup_hw function.
>
> [1] https://git.trustedfirmware.org/TF-A/trusted-firmware-a.git/tree/drivers/marvell/comphy/phy-comphy-3700.c?h=v2.3-rc2#n836
>
> Signed-off-by: Marek Behún <marek.behun@nic.cz>
> Cc: Miquèl Raynal <miquel.raynal@bootlin.com>
> ---
> drivers/pci/controller/pci-aardvark.c | 69 +++++++++++++++++++++++++++
> 1 file changed, 69 insertions(+)
>

Reviewed-by: Rob Herring <robh@kernel.org>