Freescale has stated [1] that the LVDS clock source of the IMX6 does not
pass the PCI Gen2 clock jitter test, therefore unless an external Gen2
compliant external clock source is present and supplied back to the IMX6
PCIe core via LVDS CLK1/CLK2 you can not claim Gen2 compliance.

Add a DT property to specify Gen1 vs Gen2 and check this before allowing a
Gen2 link.

We default to Gen1 if the property is not present because at this time
there are no IMX6 boards in mainline that 'input' a clock on LVDS
CLK1/CLK2.

In order to be Gen2 compliant on IMX6 you need to:

 - Have a Gen2 compliant external clock generator and route that clock back
   to either LVDS CLK1 or LVDS CLK2 as an input (see IMX6SX-SabreSD
   reference design).

 - Specify this clock in the PCIe node in the DT (i.e.,
   IMX6QDL_CLK_LVDS1_IN or IMX6QDL_CLK_LVDS2_IN instead of
   IMX6QDL_CLK_LVDS1_GATE which configures it as a CLK output).

[1] https://community.freescale.com/message/453209Signed-off-by: NTim Harvey <tharvey@gateworks.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: NLucas Stach <l.stach@pengutronix.de>
CC: Fabio Estevam <fabio.estevam@freescale.com>
CC: Zhu Richard <Richard.Zhu@freescale.com>
CC: Akshay Bhat <akshay.bhat@timesys.com>
CC: Rob Herring <robh+dt@kernel.org>
CC: Shawn Guo <shawnguo@kernel.org>

Currently the reset-gpio DT property which controls the PCI bus device
reset signal defaults to active-low reset sequence (L=reset state,
H=operation state) plus the code in reset function isn't GPIO polarity
aware - it doesn't matter if the defined reset-gpio is active-low or
active-high, it will always result into active-low reset sequence.

I've tried to fix it properly and change the reset-gpio reset sequence to
be polarity-aware, but this patch has been accepted and then reverted as it
has introduced few backward incompatible issues:

1. Some DTBs, for example, imx6qdl-sabresd, don't define reset-gpio
polarity correctly:

  reset-gpio = <&gpio7 12 0>;

which means that it's defined as active-high, but in reality it's
active-low; thus it wouldn't work without a DTS fix.

2. The logic in the reset function is inverted:

	gpio_set_value_cansleep(imx6_pcie->reset_gpio, 0)
	msleep(100);
	gpio_set_value_cansleep(imx6_pcie->reset_gpio, 1);

so even if some of the i.MX6 boards had reset-gpio polarity defined
correctly in their DTSes, they would stop working.

As we can't break old DTBs, we can't fix them, so we need to introduce this
new DT reset-gpio-active-high boolean property so we can support boards
with active-high reset sequence.

This active-high reset sequence is for example needed on Apalis SoMs, where
GPIO1_IO28, used to PCIe reset is not connected directly to PERST# PCIe
signal, but it's ORed with RESETBMCU coming off the PMIC, and thus is
inverted, active-high.

Tested-by: Tim Harvey <tharvey@gateworks.com>	# Gateworks Ventana boards (which have active-low PERST#)
Signed-off-by: NPetr Štetiar <ynezz@true.cz>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: NLucas Stach <l.stach@pengutronix.de>
Acked-by: NRob Herring <robh@kernel.org>

Add initial PCIe support for the imx6 SoC derivate imx6sx.  PCI MSI support
is untested as the necessary suspend/resume quirk is not included in this
patch.

This patch is heavily based on patches by Richard Zhu.

[bhelgaas: factor out refclk enable, fix adjacent typos in imx6q-pcie.txt]
Signed-off-by: NChristoph Fritz <chf.fritz@googlemail.com>
Acked-by: NRichard Zhu <Richard.Zhu@freescale.com>
Acked-by: NLucas Stach <l.stach@pengutronix.de>

Factor out ref clock enable to make it cleaner to add imx6sx support.  No
functional change intended.
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Tested-by: NChristoph Fritz <chf.fritz@googlemail.com>

Commit 5c5fb40d ("PCI: imx6: Add support for active-low reset GPIO")
cause regressions on some boards like MX6 Gateworks Ventana, for example.

The reason for the breakage is that this commit sets the GPIO polarity in
the wrong logic level.

Also, the commit log is wrong because active-low reset GPIO is what the
driver used to support since the beginning.

So keep the old behavior that ignores the GPIO polarity specified in the
device tree and treat the PCI reset GPIO as active-low.
Reported-by: NKrzysztof Hałasa <khalasa@piap.pl>
Tested-by: Tim Harvey <tharvey@gateworks.com>	# Gateworks Ventana
Signed-off-by: NFabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Acked-by: NTim Harvey <tharvey@gateworks.com>
Acked-by: NLucas Stach <l.stach@pengutronix.de>
CC: stable@vger.kernel.org	# v4.5+

Revert 5c3b99d0 ("PCI: dra7xx: Mark driver as broken").

1c96bee4 ("ARM: DRA7: hwmod: Add custom reset handler for PCIeSS")
added support to de-assert PCIe reset, so DRA7x PCIe is not broken anymore.
Signed-off-by: NSekhar Nori <nsekhar@ti.com>
Signed-off-by: NKishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

Add a reference platform driver for PCI RC IP Protoyping Kits based on the
ARC SDP.

[bhelgaas: changelog, split patch up, MAINTAINERS update]
Signed-off-by: NJoao Pinto <jpinto@synopsys.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Acked-by: NPratyush Anand <pratyush.anand@gmail.com>

Add a default DesignWare "link_up" test for use when a sub-driver doesn't
supply its own pcie_host_ops.link_up() method.

[bhelgaas: changelog, split into its own patch]
Signed-off-by: NJoao Pinto <jpinto@synopsys.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Acked-by: NPratyush Anand <pratyush.anand@gmail.com>

Several DesignWare-based drivers (dra7xx, exynos, imx6, keystone, qcom, and
spear13xx) had similar loops waiting for the link to come up.

Add a generic dw_pcie_wait_for_link() for use by all these drivers so the
waiting is done consistently, e.g., always using usleep_range() rather than
mdelay() and using similar timeouts and retry counts.

Note that this changes the Keystone link training/wait for link strategy,
so we initiate link training, then wait longer for the link to come up
before re-initiating link training.

[bhelgaas: changelog, split into its own patch, update pci-keystone.c, pcie-qcom.c]
Signed-off-by: NJoao Pinto <jpinto@synopsys.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Acked-by: NPratyush Anand <pratyush.anand@gmail.com>

The cavium,pci-thunder-ecam devices are exactly ECAM-based PCI root
complexes.  These root complexes (loosely referred to as ECAM units in the
hardware manuals) are used to access the Thunder on-chip devices.  They
are special in that all the BARs on devices behind these root complexes are
at fixed addresses.

Add a driver for these devices that synthesizes Enhanced Allocation (EA)
capability entries for each BAR.

Since this EA synthesis is needed for exactly two chip models, we can hard-
code some assumptions about the device topology and the layout of the
config space of specific DEVFNs in the driver.

[bhelgaas: changelog, whitespace]
Signed-off-by: NDavid Daney <david.daney@cavium.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Acked-by: NRob Herring <robh@kernel.org>

The root complexes used to access off-chip PCIe devices (called PEM units
in the hardware manuals) on some Cavium ThunderX processors require quirky
access methods for the config space of the PCIe bridge.

Add a driver to provide these config space accessor functions.  Use the
pci-host-common code to configure the PCI machinery.
Signed-off-by: NDavid Daney <david.daney@cavium.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Acked-by: NRob Herring <robh@kernel.org>
Acked-by: NArnd Bergmann <arnd@arndb.de>

Move pci_host_common_probe() and associated functions to pci-host-common.c,
where it can be shared with other drivers.  Make it public (not static)
and update Kconfig and Makefile to build it.  No functional change
intended.

[bhelgaas: split into separate patch, changelog]
Signed-off-by: NDavid Daney <david.daney@cavium.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Acked-by: NWill Deacon <will.deacon@arm.com>

Factor gen_pci_probe(), moving most of it into pci_host_common_probe()
where it can be shared with other drivers that have slightly different
config accessors.  No functional change intended.

[bhelgaas: split into separate patch, changelog]
Signed-off-by: NDavid Daney <david.daney@cavium.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Acked-by: NWill Deacon <will.deacon@arm.com>

Move definitions for generic PCI host controller driver structures to a
separate header file so we can share them with other drivers.  No
functional change intended.

[bhelgaas: split into separate patch, changelog]
Signed-off-by: NDavid Daney <david.daney@cavium.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Acked-by: NWill Deacon <will.deacon@arm.com>

Add PCIe Root Port driver for Xilinx PCIe NWL bridge IP.

[bhelgaas: wait for link like dw_pcie_wait_for_link(), simplify bitmap
error path, typos, whitespace, fold in Dan Carpenter's PTR_ERR() fix]
Signed-off-by: NBharat Kumar Gogada <bharatku@xilinx.com>
Signed-off-by: NRavi Kiran Gummaluri <rgummal@xilinx.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: NMarc Zyngier <marc.zyngier@arm.com>
Acked-by: NRob Herring <robh@kernel.org>

A SerDes PHY is optional, so if devm_phy_get() doesn't find one at all,
that's fine.  But if devm_phy_get() finds a PHY that doesn't have a driver
yet, it returns -EPROBE_DEFER.  In that case, defer probing the Keystone
driver.  We may be able to load it later after a PHY driver is loaded.

[bhelgaas: changelog, check for -EPROBE_DEFER first]
Signed-off-by: NShawn Lin <shawn.lin@rock-chips.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

Originally altera_pcie_link_is_up() decided the link was up if any of the
low four bits of the LTSSM register were set.  But the link is only up if
the LTSSM state is L0, so check for that exact value.

[bhelgaas: changelog]
Signed-off-by: NLey Foon Tan <lftan@altera.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

Make the R-Car drivers depend on ARCH_RENESAS instead of ARCH_SHMOBILE.

This is part of an ongoing process to migrate from ARCH_SHMOBILE to
ARCH_RENESAS.  The motivation is that RENESAS seems to be a more
appropriate name than SHMOBILE for the majority of Renesas ARM-based SoCs.
Signed-off-by: NSimon Horman <horms+renesas@verge.net.au>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Acked-by: NGeert Uytterhoeven <geert+renesas@glider.be>

BARs are disabled when the size register is 0, so it's misleading to write
a base address into the start register.
Signed-off-by: NThierry Reding <treding@nvidia.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

Track the offsets of the bus -> CPU mapping for I/O and memory.  This is
cosmetic for current Tegra chips because the offset is always 0.  But to
properly support legacy use-cases, like VGA, this would be needed so that
PCI bus addresses can be relocated.

While at it, also request the I/O resource both in physical memory and I/O
space to make /proc/iomem consistent, as well as add the I/O region to the
list of host bridge resources.
Signed-off-by: NThierry Reding <treding@nvidia.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

The num_ports field of the tegra_pcie structure is never used so remove it.
Signed-off-by: NThierry Reding <treding@nvidia.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

The configuration space mapping on Tegra is somewhat special, and in order
to avoid wasting virtual address space the configuration space for each bus
needs to be stitched together from several blocks which form a single
continuous virtual address range for accessors.

Currently the configuration space is mapped upon the first access to one of
its registers.  However, the mapping operation may sleep under certain
circumstances, so doing it from the configuration space accessors (they are
protected by a spin lock) will trigger a warning.

To avoid the warning, use the ->add_bus() callback to perform the mapping
at enumeration time when the operation is allowed to sleep.  Also add an
implementation of ->remove_bus() that undoes the mapping established by the
->add_bus() callback.  While it isn't currently possible to unload the
module, there is work underway to remedy this, and this code will come in
handy when that happens.
Signed-off-by: NThierry Reding <treding@nvidia.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

Modify the Microblaze PCI subsystem to work with the generic
drivers/pci/host/pcie-xilinx.c driver on Microblaze and Zynq.

[bhelgaas: changelog]
Signed-off-by: NBharat Kumar Gogada <bharatku@xilinx.com>
Signed-off-by: NRavi Kiran Gummaluri <rgummal@xilinx.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Acked-by: NMichal Simek <michal.simek@xilinx.com>

The Xilinx AXI PCIe Host Bridge Soft IP driver was previously only
supported on ARM (in particular, on ARCH_ZYNC), and pci_fixup_irqs() is
available there.  But Microblaze will do IRQ fixup in pcibios_add_device(),
so pci_fixup_irqs() is not available on Microblaze.

Don't call pci_fixup_irqs() on Microblaze, so the driver can work on both
Zynq and Microblaze Architectures.

[bhelgaas: revise changelog to show similarity to bdb8a184 ("PCI: iproc: Call pci_fixup_irqs() for ARM64 as well as ARM")]
Signed-off-by: NBharat Kumar Gogada <bharatku@xilinx.com>
Signed-off-by: NRavi Kiran Gummaluri <rgummal@xilinx.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: NArnd Bergmann <arnd@arndb.de>
Acked-by: NMichal Simek <michal.simek@xilinx.com>

The Xilinx PCIe host controller driver uses pci_common_init_dev(), which
is ARM-specific and requires the ARM struct hw_pci.  The part of
pci_common_init_dev() that is needed is limited and can be done here
without using hw_pci.

Create and scan the root bus directly without using the ARM
pci_common_init_dev() interface.

[bhelgaas: revise changelog to show similarity to 79953dd2 ("PCI: rcar: Remove dependency on ARM-specific struct hw_pci")]
Signed-off-by: NBharat Kumar Gogada <bharatku@xilinx.com>
Signed-off-by: NRavi Kiran Gummaluri <rgummal@xilinx.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: NArnd Bergmann <arnd@arndb.de>
Acked-by: NMichal Simek <michal.simek@xilinx.com>

Use the new of_pci_get_host_bridge_resources() API in place of the PCI OF
DT parser.

[bhelgaas: revise changelog to show similarity to 0021d22b ("PCI: designware: Use of_pci_get_host_bridge_resources() to parse DT")]
Signed-off-by: NBharat Kumar Gogada <bharatku@xilinx.com>
Signed-off-by: NRavi Kiran Gummaluri <rgummal@xilinx.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: NArnd Bergmann <arnd@arndb.de>
Acked-by: NMichal Simek <michal.simek@xilinx.com>

The settings in GPR8 are dependent upon the particular layout of the
hardware platform.  As such, they should be configurable via the device
tree.

Look up PHY Tx driver settings from the device tree.  Fall back to the
original hard-coded values if they are not specified in the device tree.
Signed-off-by: NJustin Waters <justin.waters@timesys.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Acked-by: NLucas Stach <l.stach@pengutronix.de>

Some kinds of Layerscape PCIe controllers will forward the received message
TLPs to system application address space, which could corrupt system memory
or lead to a system hang.  Enable MSG_DROP to fix this issue.
Signed-off-by: NMinghuan Lian <Minghuan.Lian@nxp.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

Commit cbce7900 ("PCI: designware: Make driver arch-agnostic") changed
the host bridge sysdata pointer from the ARM pci_sys_data to the DesignWare
pcie_port structure, and changed pcie-designware.c to reflect that.  But it
did not change the corresponding code in pci-keystone-dw.c, so it caused
crashes on Keystone:

  Unable to handle kernel NULL pointer dereference at virtual address 00000030
  pgd = c0003000
  [00000030] *pgd=80000800004003, *pmd=00000000
  Internal error: Oops: 206 [#1] PREEMPT SMP ARM
  CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.4.2-00139-gb74f926 #2
  Hardware name: Keystone
  PC is at ks_dw_pcie_msi_irq_unmask+0x24/0x58

Change pci-keystone-dw.c to expect sysdata to be the struct pcie_port
pointer.

[bhelgaas: changelog]
Fixes: cbce7900 ("PCI: designware: Make driver arch-agnostic")
Signed-off-by: NMurali Karicheri <m-karicheri2@ti.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
CC: stable@vger.kernel.org	# v4.4+
CC: Zhou Wang <wangzhou1@hisilicon.com>

This driver uses PCI glue that is only available on 32-bit ARM.  This used
to work fine as long as ARCH_MVEBU and ARCH_DOVE were exclusively 32-bit,
but there's a patch in the pipe to make ARCH_MVEBU also available on 64-bit
ARM.

[bhelgaas: changelog; patch is coming but not merged yet]
Signed-off-by: NThierry Reding <treding@nvidia.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Acked-by: NThomas Petazzoni <thomas.petazzoni@free-electrons.com>

Add a new driver which exposes a root PCI bus whenever a PCI Express device
is passed through to a guest VM under Hyper-V.  The device can be single-
or multi-function.  The interrupts for the devices are managed by an IRQ
domain, implemented within the driver.

[bhelgaas: fold in race condition fix (http://lkml.kernel.org/r/1456340196-13717-1-git-send-email-jakeo@microsoft.com)]
Signed-off-by: NJake Oshins <jakeo@microsoft.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

The PCIe designware host driver is not used in system configurations
requiring the PCI_PROBE_ONLY flag to be set to prevent resources
assignment, therefore the driver code handling the flag can be removed
from the kernel.
Signed-off-by: NLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Acked-by: NPratyush Anand <pratyush.anand@gmail.com>
Acked-by: NJingoo Han Jingoo Han <jingoohan1@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Gabriele Paoloni <gabriele.paoloni@huawei.com>
Cc: Zhou Wang <wangzhou1@hisilicon.com>

Some platforms don't support ATU, e.g., pci-keystone.c.  These platforms
use their own address translation component rather than ATU, and they
provide the rd_other_conf and wr_other_conf methods to program the
translation component and perform the access.

Add a comment to explain why we don't program the ATU for these platforms.

[bhelgaas: changelog]
Signed-off-by: NJisheng Zhang <jszhang@marvell.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

The Layerscape PCI host driver must recognize ls2085a compatible when using
firmware with ls2085a compatible property, otherwise the PCI bus won't be
detected even though ls2085a compatible is included by the dts.
Signed-off-by: NYang Shi <yang.shi@linaro.org>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

The PCIe rcar host driver is not used in system configurations requiring
the PCI_PROBE_ONLY flag to be set to prevent resources assignment,
therefore the driver code handling the flag can be removed from the kernel.
Signed-off-by: NLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Acked-by: NSimon Horman <horms+renesas@verge.net.au>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Phil Edworthy <phil.edworthy@renesas.com>

Commit 943ebae7 ("PCI: iproc: Add PAXC interface support") only allowed
device 0, which is a regression on BCMA-based platforms.

All systems support only one device, a Root Port at 00:00.0, on the root
bus.  PAXC-based systems support only the Root Port (00:00.0) and a single
device (with multiple functions) below it, e.g., 01:00.0, 01:00.1, etc.
Non-PAXC systems support arbitrary devices below the Root Port.

[bhelgaas: changelog, fold in removal of MAX_NUM_PAXC_PF check]
Fixes: 943ebae7 ("PCI: iproc: Add PAXC interface support")
Reported-by: NRafal Milecki <zajec5@gmail.com>
Signed-off-by: NRay Jui <rjui@broadcom.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

imx6_pcie_link_up() previously used usleep_range() to wait for the link to
come up.  Since it may be called while holding the config spinlock, the
sleep causes a "BUG: scheduling while atomic" error.

Instead of waiting for the link to come up in imx6_pcie_link_up(), do the
waiting in imx6_pcie_wait_for_link(), where we're not holding a lock and
sleeping is allowed.

[bhelgaas: changelog, references to bugzilla and f95d3ae7]
Link: https://bugzilla.kernel.org/show_bug.cgi?id=100031
Fixes: f95d3ae7 ("PCI: imx6: Wait for retraining")
Signed-off-by: NLucas Stach <l.stach@pengutronix.de>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

Remove the remnants of the workaround for erratum ERR005184 which was never
completely implemented.  The checks alone don't carry any value as we don't
act properly on the result.

A workaround should be added to the lane speed change in establish_link
later.
Signed-off-by: NLucas Stach <l.stach@pengutronix.de>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

This adds the PHY reset into a common error path of
imx6_pcie_establish_link(), deduplicating some of the debug prints.  Also
reduce the severity of the "no-link" message in the one place where it is
expected to be hit when no peripheral is attached.
Signed-off-by: NLucas Stach <l.stach@pengutronix.de>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

Move imx6_pcie_reset_phy() near the other PHY related functions in the
file.  This is a cosmetic change, but also allows to do the following
changes without introducing needless forward declarations.
Signed-off-by: NLucas Stach <l.stach@pengutronix.de>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>