PCI: dw-rockchip: Fix initial PERST# GPIO value

commit 28b8d7793b8573563b3d45321376f36168d77b1e upstream.

PERST# is active low according to the PCIe specification.

However, the existing pcie-dw-ro

PCI: dw-rockchip: Fix initial PERST# GPIO value

commit 28b8d7793b8573563b3d45321376f36168d77b1e upstream.

PERST# is active low according to the PCIe specification.

However, the existing pcie-dw-rockchip.c driver does:

gpiod_set_value(..., 0); msleep(100); gpiod_set_value(..., 1);

when asserting + deasserting PERST#.

This is of course wrong, but because all the device trees for this
compatible string have also incorrectly marked this GPIO as ACTIVE_HIGH:

$ git grep -B 10 reset-gpios arch/arm64/boot/dts/rockchip/rk3568*
$ git grep -B 10 reset-gpios arch/arm64/boot/dts/rockchip/rk3588*

The actual toggling of PERST# is correct, and we cannot change it anyway,
since that would break device tree compatibility.

However, this driver does request the GPIO to be initialized as
GPIOD_OUT_HIGH, which does cause a silly sequence where PERST# gets
toggled back and forth for no good reason.

Fix this by requesting the GPIO to be initialized as GPIOD_OUT_LOW (which
for this driver means PERST# asserted).

This will avoid an unnecessary signal change where PERST# gets deasserted
(by devm_gpiod_get_optional()) and then gets asserted (by
rockchip_pcie_start_link()) just a few instructions later.

Before patch, debug prints on EP side, when booting RC:

[ 845.606810] pci: PERST# asserted by host!
[ 852.483985] pci: PERST# de-asserted by host!
[ 852.503041] pci: PERST# asserted by host!
[ 852.610318] pci: PERST# de-asserted by host!

After patch, debug prints on EP side, when booting RC:

[ 125.107921] pci: PERST# asserted by host!
[ 132.111429] pci: PERST# de-asserted by host!

This extra, very short, PERST# assertion + deassertion has been reported to
cause issues with certain WLAN controllers, e.g. RTL8822CE.

Fixes: 0e898eb8df4e ("PCI: rockchip-dwc: Add Rockchip RK356X host controller driver")
Link: https://lore.kernel.org/linux-pci/20240417164227.398901-1-cassel@kernel.org
Tested-by: Heiko Stuebner <heiko@sntech.de>
Tested-by: Jianfeng Liu <liujianfeng1994@gmail.com>
Signed-off-by: Niklas Cassel <cassel@kernel.org>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Cc: stable@vger.kernel.org # v5.15+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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PCI: Explicitly include correct DT includes

The DT of_device.h and of_platform.h date back to the separate
of_platform_bus_type before it as merged into the regular platform bus. As
part of that me

PCI: Explicitly include correct DT includes

The DT of_device.h and of_platform.h date back to the separate
of_platform_bus_type before it as merged into the regular platform bus. As
part of that merge prepping Arm DT support 13 years ago, they "temporarily"
include each other. They also include platform_device.h and of.h. As a
result, there's a pretty much random mix of those include files used
throughout the tree. In order to detangle these headers and replace the
implicit includes with struct declarations, users need to explicitly
include the correct includes.

Link: https://lore.kernel.org/r/20230714174827.4061572-1-robh@kernel.org
Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

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PCI: dwc: Rename struct pcie_port to dw_pcie_rp

All of the DW PCIe core driver entities except the pcie_port struct have
names with the "dw_" prefix to distinguish local and common PCIe name
spaces,

PCI: dwc: Rename struct pcie_port to dw_pcie_rp

All of the DW PCIe core driver entities except the pcie_port struct have
names with the "dw_" prefix to distinguish local and common PCIe name
spaces, and endpoint-related entities have an "_ep" suffix.

Rename struct pcie_port to dw_pcie_rp to make it more consistent with other
names.

[bhelgaas: commit log]
Link: https://lore.kernel.org/r/20220624143428.8334-16-Sergey.Semin@baikalelectronics.ru
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Acked-by: Jesper Nilsson <jesper.nilsson@axis.com>

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PCI: rockchip-dwc: Add legacy interrupt support

The legacy interrupts on the rk356x PCIe controller are handled by a
single muxed interrupt. Add IRQ domain support to the pcie-dw-rockchip
driver to

PCI: rockchip-dwc: Add legacy interrupt support

The legacy interrupts on the rk356x PCIe controller are handled by a
single muxed interrupt. Add IRQ domain support to the pcie-dw-rockchip
driver to support the virtual domain.

Link: https://lore.kernel.org/r/20220429123832.2376381-4-pgwipeout@gmail.com
Signed-off-by: Peter Geis <pgwipeout@gmail.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Marc Zyngier <maz@kernel.org>

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PCI: rockchip-dwc: Reset core at driver probe

The PCIe controller is in an unknown state at driver probe. This can
lead to undesireable effects when the driver attempts to configure the
controller.

PCI: rockchip-dwc: Reset core at driver probe

The PCIe controller is in an unknown state at driver probe. This can
lead to undesireable effects when the driver attempts to configure the
controller.

Prevent issues in the future by resetting the core during probe.

Link: https://lore.kernel.org/r/20220429123832.2376381-3-pgwipeout@gmail.com
Tested-by: Nicolas Frattaroli <frattaroli.nicolas@gmail.com>
Signed-off-by: Peter Geis <pgwipeout@gmail.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

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PCI: rockchip-dwc: Add Rockchip RK356X host controller driver

Add a driver for the DesignWare-based PCIe controller found on
RK356X. The existing pcie-rockchip-host driver is only used for
the Rockc

PCI: rockchip-dwc: Add Rockchip RK356X host controller driver

Add a driver for the DesignWare-based PCIe controller found on
RK356X. The existing pcie-rockchip-host driver is only used for
the Rockchip-designed IP found on RK3399.

Link: https://lore.kernel.org/r/20210625065511.1096935-1-xxm@rock-chips.com
Tested-by: Peter Geis <pgwipeout@gmail.com>
Signed-off-by: Simon Xue <xxm@rock-chips.com>
Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>
Reviewed-by: Rob Herring <robh@kernel.org>

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