Revert commit 3d71746c42 ("PCI: armada8k: Add support for gpio controlled
reset signal").

That commit breaks boot on Macchiatobin board when a Mellanox NIC is
present in the PCIe slot.

It turns out that full reset cycle requires first comphy serdes
initialization. Reset signal toggle without comphy initialization makes
access to PCI configuration registers stall indefinitely. U-Boot toggles
the Macchiatobin PCIe reset line already at boot, after initializing the
comphy serdes.

So while commit 3d71746c42 ("PCI: armada8k: Add support for gpio controlled
reset signal") enables PCIe on platforms that U-Boot does not touch the
reset line (like Clearfog GT-8K), it breaks PCIe (and boot) on the
Macchiatobin board.

Revert commit 3d71746c42 ("PCI: armada8k: Add support for gpio controlled
reset signal") entirely to fix the Macchiatobin regression.

Reported-by: Sven Auhagen <sven.auhagen@voleatech.de>
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

The check on the device_link_add() return value is wrong;
this leads to erroneous code execution, so fix it.

Fixes: 3f7cceeab895 ("PCI: imx: Add multi-pd support")
Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
[lorenzo.pieralisi@arm.com: updated commit log]
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

On chips without a separate power domain for PCI (such as 6q/6qp) the
imx6_pcie_attach_pd() function incorrectly returns an error.

Fix by returning 0 if dev_pm_domain_attach_by_name() does not find
anything.

Fixes: 3f7cceeab895 ("PCI: imx: Add multi-pd support")
Reported-by: Lukas F.Hartmann <lukas@mntmn.com>
Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
[lorenzo.pieralisi@arm.com: updated commit log]
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

Building the driver when GPIOLIB=n is not selected is causing the following
compilation failure:

  drivers/pci/controller/dwc/pci-meson.c: In function 'meson_pcie_assert_reset':
  drivers/pci/controller/dwc/pci-meson.c:290:2: error: implicit declaration of function 'gpiod_set_value_cansleep'; did you mean 'gpio_set_value_cansleep'? [-Werror=implicit-function-declaration]
    gpiod_set_value_cansleep(mp->reset_gpio, 0);
    ^~~~~~~~~~~~~~~~~~~~~~~~
    gpio_set_value_cansleep
  drivers/pci/controller/dwc/pci-meson.c: In function 'meson_pcie_probe':
  drivers/pci/controller/dwc/pci-meson.c:540:19: error: implicit declaration of function 'devm_gpiod_get'; did you mean 'devm_gpio_free'? [-Werror=implicit-function-declaration]
    mp->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
		     ^~~~~~~~~~~~~~
		     devm_gpio_free
  drivers/pci/controller/dwc/pci-meson.c:540:48: error: 'GPIOD_OUT_LOW' undeclared (first use in this function); did you mean 'GPIOF_INIT_LOW'?
    mp->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
						  ^~~~~~~~~~~~~
						  GPIOF_INIT_LOW

Add the missing linux/gpio/consumer.h header to fix it.

Fixes: 9c0ef6d34fdb ("PCI: amlogic: Add the Amlogic Meson PCIe controller driver")
Signed-off-by: Corentin Labbe <clabbe@baylibre.com>
[lorenzo.pieralisi@arm.com: commit log]
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

Pull PCI updates from Bjorn Helgaas:

 - Remove unused lists from ASPM pcie_link_state (Frederick Lawler)

 - Fix Broadcom CNB20LE host bridge unintended sign extension (Colin Ian
   King)

 - Expand Kconfig "PF" acronyms (Randy Dunlap)

 - Update MAINTAINERS for arch/x86/kernel/early-quirks.c (Bjorn Helgaas)

 - Add missing include to drivers/pci.h (Alexandru Gagniuc)

 - Override Synopsys USB 3.x HAPS device class so dwc3-haps can claim it
   instead of xhci (Thinh Nguyen)

 - Clean up P2PDMA documentation (Randy Dunlap)

 - Allow runtime PM even if driver doesn't supply callbacks (Jarkko
   Nikula)

 - Remove status check after submitting Switchtec MRPC Firmware Download
   commands to avoid Completion Timeouts (Kelvin Cao)

 - Set Switchtec coherent DMA mask to allow 64-bit DMA (Boris Glimcher)

 - Fix Switchtec SWITCHTEC_IOCTL_EVENT_IDX_ALL flag overwrite issue
   (Joey Zhang)

 - Enable write combining for Switchtec MRPC Input buffers (Kelvin Cao)

 - Add Switchtec MRPC DMA mode support (Wesley Sheng)

 - Skip VF scanning on powerpc, which does this in firmware (Sebastian
   Ott)

 - Add Amlogic Meson PCIe controller driver and DT bindings (Yue Wang)

 - Constify histb dw_pcie_host_ops structure (Julia Lawall)

 - Support multiple power domains for imx6 (Leonard Crestez)

 - Constify layerscape driver data (Stefan Agner)

 - Update imx6 Kconfig to allow imx6 PCIe in imx7 kernel (Trent Piepho)

 - Support armada8k GPIO reset (Baruch Siach)

 - Support suspend/resume support on imx6 (Leonard Crestez)

 - Don't hard-code DesignWare DBI/ATU offst (Stephen Warren)

 - Skip i.MX6 PHY setup on i.MX7D (Andrey Smirnov)

 - Remove Jianguo Sun from HiSilicon STB maintainers (Lorenzo Pieralisi)

 - Mask DesignWare interrupts instead of disabling them to avoid lost
   interrupts (Marc Zyngier)

 - Add locking when acking DesignWare interrupts (Marc Zyngier)

 - Ack DesignWare interrupts in the proper callbacks (Marc Zyngier)

 - Use devm resource parser in mediatek (Honghui Zhang)

 - Remove unused mediatek "num-lanes" DT property (Honghui Zhang)

 - Add UniPhier PCIe controller driver and DT bindings (Kunihiko
   Hayashi)

 - Enable MSI for imx6 downstream components (Richard Zhu)

* tag 'pci-v4.21-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: (40 commits)
  PCI: imx: Enable MSI from downstream components
  s390/pci: skip VF scanning
  PCI/IOV: Add flag so platforms can skip VF scanning
  PCI/IOV: Factor out sriov_add_vfs()
  PCI: uniphier: Add UniPhier PCIe host controller support
  dt-bindings: PCI: Add UniPhier PCIe host controller description
  PCI: amlogic: Add the Amlogic Meson PCIe controller driver
  dt-bindings: PCI: meson: add DT bindings for Amlogic Meson PCIe controller
  arm64: dts: mt7622: Remove un-used property for PCIe
  arm: dts: mt7623: Remove un-used property for PCIe
  dt-bindings: PCI: MediaTek: Remove un-used property
  PCI: mediatek: Remove un-used variant in struct mtk_pcie_port
  MAINTAINERS: Remove Jianguo Sun from HiSilicon STB DWC entry
  PCI: dwc: Don't hard-code DBI/ATU offset
  PCI: imx: Add imx6sx suspend/resume support
  PCI: armada8k: Add support for gpio controlled reset signal
  PCI: dwc: Adjust Kconfig to allow IMX6 PCIe host on IMX7
  PCI: dwc: layerscape: Constify driver data
  PCI: imx: Add multi-pd support
  PCI: Override Synopsys USB 3.x HAPS device class
  ...

  - Enable MSI for imx6 downstream components (Richard Zhu)

* pci/imx6:
  PCI: imx: Enable MSI from downstream components

  - Add UniPhier PCIe controller driver and DT bindings (Kunihiko Hayashi)

* remotes/lorenzo/pci/uniphier:
  PCI: uniphier: Add UniPhier PCIe host controller support
  dt-bindings: PCI: Add UniPhier PCIe host controller description

# Conflicts:
#	drivers/pci/controller/dwc/Kconfig
#	drivers/pci/controller/dwc/Makefile

  - Mask DesignWare interrupts instead of disabling them to avoid lost
    interrupts (Marc Zyngier)

  - Add locking when acking DesignWare interrupts (Marc Zyngier)

  - Ack DesignWare interrupts in the proper callbacks (Marc Zyngier)

* remotes/lorenzo/pci/dwc-msi:
  PCI: dwc: Move interrupt acking into the proper callback
  PCI: dwc: Take lock when ACKing an interrupt
  PCI: dwc: Use interrupt masking instead of disabling

  - Constify histb dw_pcie_host_ops structure (Julia Lawall)

  - Support multiple power domains for imx6 (Leonard Crestez)

  - Constify layerscape driver data (Stefan Agner)

  - Update imx6 Kconfig to allow imx6 PCIe in imx7 kernel (Trent Piepho)

  - Support armada8k GPIO reset (Baruch Siach)

  - Support suspend/resume support on imx6 (Leonard Crestez)

  - Don't hard-code DesignWare DBI/ATU offst (Stephen Warren)

  - Skip i.MX6 PHY setup on i.MX7D (Andrey Smirnov)

  - Remove Jianguo Sun from HiSilicon STB maintainers (Lorenzo Pieralisi)

* remotes/lorenzo/pci/dwc:
  MAINTAINERS: Remove Jianguo Sun from HiSilicon STB DWC entry
  PCI: dwc: Don't hard-code DBI/ATU offset
  PCI: imx: Add imx6sx suspend/resume support
  PCI: armada8k: Add support for gpio controlled reset signal
  PCI: dwc: Adjust Kconfig to allow IMX6 PCIe host on IMX7
  PCI: dwc: layerscape: Constify driver data
  PCI: imx: Add multi-pd support
  dt-bindings: imx6q-pcie: Add multi-pd bindings for imx6sx
  PCI: histb: Constify dw_pcie_host_ops structure

The MSI Enable bit in the MSI Capability (PCIe r4.0, sec 7.7.1.2) controls
whether a Function can request service using MSI.

i.MX6 Root Ports implement the MSI Capability and may use MSI to request
service for events like PME, hotplug, AER, etc.  In addition, on i.MX6, the
MSI Enable bit controls delivery of MSI interrupts from components below
the Root Port.

Prior to f3fdfc4ac3a2 ("PCI: Remove host driver Kconfig selection of
CONFIG_PCIEPORTBUS"), enabling CONFIG_PCI_IMX6 automatically also enabled
CONFIG_PCIEPORTBUS, and when portdrv claimed the Root Ports, it set the MSI
Enable bit so it could use PME, hotplug, AER, etc.  As a side effect, that
also enabled delivery of MSI interrupts from downstream components.

The imx6q-pcie driver itself does not depend on portdrv, so set MSI Enable
in imx6q-pcie so MSI from downstream components works even if nobody uses
MSI for the Root Port events.

Fixes: f3fdfc4ac3a2 ("PCI: Remove host driver Kconfig selection of CONFIG_PCIEPORTBUS")
Signed-off-by: Richard Zhu <hongxing.zhu@nxp.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: Sven Van Asbroeck <TheSven73@googlemail.com>
Tested-by: Trent Piepho <tpiepho@impinj.com>
Reviewed-by: Lucas Stach <l.stach@pengutronix.de>
Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>