Many PCI host controller drivers aren't prepared to have their devices
unbound from them forcefully (e.g., through /sys/.../<driver>/unbind), as
they don't provide any driver .remove callback, where they'd detach the
root bus, release resources, etc. Keeping the driver built in (i.e., not a
loadable module) is not enough; and providing no .remove callback just
means we don't do any teardown.

To rule out the possibility of unbinding a device via sysfs, we need to set
the ".suppress_bind_attrs" field.

I found the suspect drivers via the following search:

  git grep -l platform_driver $(git grep -L -e '\.remove' -e suppress_bind_attrs drivers/pci/)

Then I inspected them to ensure that
(a) they set up a PCI bus in their probe() and
(b) they don't have a remove() callback for undoing the setup
Suggested-by: NBjorn Helgaas <helgaas@kernel.org>
Signed-off-by: NBrian Norris <briannorris@chromium.org>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

Trivial fix to spelling mistake in dev_err message
Signed-off-by: NColin Ian King <colin.king@canonical.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Acked-by: NRichard Zhu <hongxing.Zhu@nxp.com>

Save a bit of time and avoid going through link speed change procedure in
configuration where link max speed is limited to Gen1 in DT.
Signed-off-by: NAndrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: NLucas Stach <l.stach@pengutronix.de>
Cc: yurovsky@gmail.com
Cc: Fabio Estevam <fabio.estevam@nxp.com>
Cc: Dong Aisheng <dongas86@gmail.com>
Cc: linux-arm-kernel@lists.infradead.org

As can be seen from [1]:

  "...the different behavior between iMX6Q PCIe and iMX7D PCIe maybe caused
  by the different controller version.

  Regarding to the DOC description, the DIRECT_SPEED_CHANGE should be
  cleared after the speed change from GEN1 to GEN2. Unfortunately, when
  GEN1 device is used, the behavior is not documented.

  So, IC design guys run the simulation and find out the following
  behaviors:

     1. DIRECT_SPEED_CHANGE will be cleared in 7D after speed change
     	from GEN1 to GEN2. This matches doc’s description

     2. set MAX link speed(PCIE_CAP_TARGET_LINK_SPEED=0x01) as GEN1 and
     	re-run the simulation, DIRECT_SPEED_CHANGE will not be cleared;
     	remain as 1, this matches your result, but function test is
     	passed, so this bit should not affect the normal PCIe function."

imx6_pcie_wait_for_speed_change() will report false failures for Gen1 ->
Gen1 speed transition, so avoid doing that check and just rely on
imx6_pcie_wait_for_link() only.

[1] https://community.nxp.com/message/867943Signed-off-by: NAndrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: NLucas Stach <l.stach@pengutronix.de>
Cc: yurovsky@gmail.com
Cc: Fabio Estevam <fabio.estevam@nxp.com>
Cc: Dong Aisheng <dongas86@gmail.com>
Cc: linux-arm-kernel@lists.infradead.org

Some designs implement reset GPIO via a GPIO expander connected to a
peripheral bus.  One such example would be i.MX7 Sabre board where said
GPIO is provided by SPI shift register connected to a bitbanged SPI bus.
To support such designs, allow reset GPIO request to defer probing of the
driver.
Signed-off-by: NAndrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: NLucas Stach <l.stach@pengutronix.de>
Cc: yurovsky@gmail.com
Cc: Fabio Estevam <fabio.estevam@nxp.com>
Cc: Dong Aisheng <dongas86@gmail.com>
Cc: linux-arm-kernel@lists.infradead.org

Add various bits of code needed to support i.MX7D variant of the IP.
Signed-off-by: NAndrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: NLucas Stach <l.stach@pengutronix.de>
Acked-by: NLee Jones <lee.jones@linaro.org>
Acked-by: NRob Herring <robh@kernel.org>
Cc: yurovsky@gmail.com
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Fabio Estevam <fabio.estevam@nxp.com>
Cc: Dong Aisheng <dongas86@gmail.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: devicetree@vger.kernel.org

Fix the following crash, seen in dwc/pci-imx6.

  Unable to handle kernel NULL pointer dereference at virtual address 00000070
  pgd = c0004000
  [00000070] *pgd=00000000
  Internal error: Oops: 805 [#1] SMP ARM
  Modules linked in:
  CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.10.0-09686-g9e314890 #1
  Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree)
  task: cb850000 task.stack: cb84e000
  PC is at imx6_pcie_probe+0x2f4/0x414
  ...

While at it, fix the same problem in various drivers instead of waiting for
individual crash reports.

The change in the imx6 driver was tested with qemu. The changes in other
drivers are based on code inspection and have been compile tested only.

Fixes: 442ec4c0 ("PCI: dwc: all: Split struct pcie_port into host-only and core structures")
Signed-off-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: Vivek Gautam <vivek.gautam@codeaurora.org>  # designware-plat
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Acked-by: NKishon Vijay Abraham I <kishon@ti.com>

Keep only the host-specific members in struct pcie_port and move the common
members (i.e common to both host and endpoint) to struct dw_pcie.  This is
in preparation for adding endpoint mode support to designware driver.

While at that also fix checkpatch warnings.
Signed-off-by: NKishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
CC: Jingoo Han <jingoohan1@gmail.com>
CC: Richard Zhu <hongxing.zhu@nxp.com>
CC: Lucas Stach <l.stach@pengutronix.de>
CC: Murali Karicheri <m-karicheri2@ti.com>
CC: Minghuan Lian <minghuan.Lian@freescale.com>
CC: Mingkai Hu <mingkai.hu@freescale.com>
CC: Roy Zang <tie-fei.zang@freescale.com>
CC: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
CC: Niklas Cassel <niklas.cassel@axis.com>
CC: Jesper Nilsson <jesper.nilsson@axis.com>
CC: Joao Pinto <Joao.Pinto@synopsys.com>
CC: Zhou Wang <wangzhou1@hisilicon.com>
CC: Gabriele Paoloni <gabriele.paoloni@huawei.com>
CC: Stanimir Varbanov <svarbanov@mm-sol.com>
CC: Pratyush Anand <pratyush.anand@gmail.com>

Add platform_set_drvdata() in all designware-based drivers to store the
private data structure of the driver so that dev_set_drvdata() can be used
to get back private data structure in add_pcie_port/host_init.  This is in
preparation for splitting struct pcie_port into core and host only
structures. After the split pcie_port will not be part of the driver's
private data structure and *container_of* used now to get the private data
pointer cannot be used.
Signed-off-by: NKishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
CC: Jingoo Han <jingoohan1@gmail.com>
CC: Richard Zhu <hongxing.zhu@nxp.com>
CC: Lucas Stach <l.stach@pengutronix.de>
CC: Murali Karicheri <m-karicheri2@ti.com>
CC: Minghuan Lian <minghuan.Lian@freescale.com>
CC: Mingkai Hu <mingkai.hu@freescale.com>
CC: Roy Zang <tie-fei.zang@freescale.com>
CC: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
CC: Niklas Cassel <niklas.cassel@axis.com>
CC: Jesper Nilsson <jesper.nilsson@axis.com>
CC: Joao Pinto <Joao.Pinto@synopsys.com>
CC: Zhou Wang <wangzhou1@hisilicon.com>
CC: Gabriele Paoloni <gabriele.paoloni@huawei.com>
CC: Stanimir Varbanov <svarbanov@mm-sol.com>
CC: Pratyush Anand <pratyush.anand@gmail.com>

Group all the PCI drivers that use DesignWare core in dwc directory.
dwc IP is capable of operating in both host mode and device mode and
keeping it inside the *host* directory is misleading.
Signed-off-by: NKishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Acked-by: NJingoo Han <jingoohan1@gmail.com>
Acked-By: NJoao Pinto <jpinto@synopsys.com>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Minghuan Lian <minghuan.Lian@freescale.com>
Cc: Mingkai Hu <mingkai.hu@freescale.com>
Cc: Roy Zang <tie-fei.zang@freescale.com>
Cc: Richard Zhu <hongxing.zhu@nxp.com>
Cc: Lucas Stach <l.stach@pengutronix.de>
Cc: Murali Karicheri <m-karicheri2@ti.com>
Cc: Pratyush Anand <pratyush.anand@gmail.com>
Cc: Niklas Cassel <niklas.cassel@axis.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Zhou Wang <wangzhou1@hisilicon.com>
Cc: Gabriele Paoloni <gabriele.paoloni@huawei.com>
Cc: Stanimir Varbanov <svarbanov@mm-sol.com>

Fix a typo in the "pcie_inbound_axi clock missing or invalid" error
message.
Signed-off-by: NAndrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Acked-by: NLucas Stach <l.stach@pengutronix.de>
CC: yurovsky@gmail.com
CC: Fabio Estevam <fabio.estevam@nxp.com>

This causes CPU hangs when the system is reset by the watchdog, as the GPRs
aren't cleared, but the clocks are back to disabled state.

If the bootloader uses PCIe, it must take care to bring it down into a safe
state, before passing control to the Linux kernel.  This is the only way to
get a properly operating system at all times and circumstances.
Signed-off-by: NLucas Stach <l.stach@pengutronix.de>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

When a PCI card is not connected, the following messages are seen on mx6:

  imx6q-pcie 1ffc000.pcie: phy link never came up
  imx6q-pcie 1ffc000.pcie: Link never came up

The first one comes from the pcie-designware.c core file, so remove
the redundant one from the imx6 driver.
Signed-off-by: NFabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: NLucas Stach <l.stach@pengutronix.de>

Remove unused return values.  No functional change intended.
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

Reorder struct imx6_pcie to put generic fields first.  No functional change
intended.
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

The dw_pcie_readl_rc() and dw_pcie_writel_rc() interfaces already add in
pp->dbi_base, so use those instead of doing it ourselves in the imx6
driver.  No functional change intended.
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

Only interfaces used from outside the driver, e.g., those called by the
DesignWare core, need to accept pointers to the generic struct pcie_port.
Internal interfaces can accept pointers to the device-specific struct,
which makes them more straightforward.  No functional change intended.
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

Pass the struct imx6_pcie pointer, not dbi_base address, to PHY accessors.
This enables future simplifications.  No functional change intended.
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

Removed the unused struct imx6_pcie.mem_base member.  No functional change
intended.
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

"np" and "node" are redundant copies of the of_node pointer.  Remove "np"
and use "node" instead.  Replace the "fsl,max-link-speed" use with "node"
as well.  No functional change intended.
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

Use a local "struct device *dev" for brevity and consistency with other
drivers.  No functional change intended.
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

This code is not being built as a module by anyone:

  drivers/pci/host/Kconfig:config PCI_IMX6
  drivers/pci/host/Kconfig:  bool "Freescale i.MX6 PCIe controller"

Remove uses of MODULE_DESCRIPTION(), MODULE_AUTHOR(), MODULE_LICENSE(),
etc., so that when reading the driver there is no doubt it is builtin-only.
The information is preserved in comments at the top of the file.

Note that for non-modular code, MODULE_DEVICE_TABLE is a no-op and
module_init() translates to device_initcall().

[bhelgaas: changelog]
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
CC: Richard Zhu <Richard.Zhu@freescale.com>
CC: Lucas Stach <l.stach@pengutronix.de>

I.MX6+ has a dedicated bit for resetting PCIe core, which should be used
instead of a regular reset sequence since using the latter will hang the
SoC.

This commit is based on c34068d48273e24d392d9a49a38be807954420ed from
http://git.freescale.com/git/cgit.cgi/imx/linux-2.6-imx.gitTested-by: NGary Bisson <gary.bisson@boundarydevices.com>
Signed-off-by: NAndrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: NFabio Estevam <fabio.estevam@nxp.com>

Use enumerated type instead of a boolean flag to specify the variant of
the PCIe IP block (6Q, 6SX, etc).  This patch has zero functional impact,
however it makes the code easier to extend for the case of more than 2
possible variants of an IP block (of which there are).

[bhelgaas: rewrap comment, remove extra blank line]
Signed-off-by: NAndrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: NFabio Estevam <fabio.estevam@nxp.com>

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+

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 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>

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>

Fix all whitespace issues (missing or needed whitespace) in all files in
drivers/pci.  Code is compiled with allyesconfig before and after code
changes and objects are recorded and checked with objdiff and they are not
changed after this commit.
Signed-off-by: NBogicevic Sasa <brutallesale@gmail.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

On -RT and if kernel is booting with "threadirqs" cmd line parameter,
PCIe/PCI (MSI) IRQ cascade handlers (like dra7xx_pcie_msi_irq_handler())
will be forced threaded and, as result, will generate warnings like this:

  WARNING: CPU: 1 PID: 82 at kernel/irq/handle.c:150 handle_irq_event_percpu+0x14c/0x174()
  irq 460 handler irq_default_primary_handler+0x0/0x14 enabled interrupts
  Backtrace:
   (warn_slowpath_common) from (warn_slowpath_fmt+0x38/0x40)
   (warn_slowpath_fmt) from (handle_irq_event_percpu+0x14c/0x174)
   (handle_irq_event_percpu) from (handle_irq_event+0x84/0xb8)
   (handle_irq_event) from (handle_simple_irq+0x90/0x118)
   (handle_simple_irq) from (generic_handle_irq+0x30/0x44)
   (generic_handle_irq) from (dra7xx_pcie_msi_irq_handler+0x7c/0x8c)
   (dra7xx_pcie_msi_irq_handler) from (irq_forced_thread_fn+0x28/0x5c)
   (irq_forced_thread_fn) from (irq_thread+0x128/0x204)

This happens because all of them invoke generic_handle_irq() from the
requested handler.  generic_handle_irq() grabs raw_locks and thus needs to
run in raw-IRQ context.

This issue was originally reproduced on TI dra7-evem, but, as was
identified during discussion [1], other hosts can also suffer from this
issue.  Fix all them at once by marking PCIe/PCI (MSI) IRQ cascade handlers
IRQF_NO_THREAD explicitly.

[1] http://lkml.kernel.org/r/1448027966-21610-1-git-send-email-grygorii.strashko@ti.com

[bhelgaas: add stable tag, fix typos]
Signed-off-by: NGrygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Acked-by: Lucas Stach <l.stach@pengutronix.de> (for imx6)
CC: stable@vger.kernel.org
CC: Kishon Vijay Abraham I <kishon@ti.com>
CC: Jingoo Han <jingoohan1@gmail.com>
CC: Kukjin Kim <kgene@kernel.org>
CC: Krzysztof Kozlowski <k.kozlowski@samsung.com>
CC: Richard Zhu <Richard.Zhu@freescale.com>
CC: Thierry Reding <thierry.reding@gmail.com>
CC: Stephen Warren <swarren@wwwdotorg.org>
CC: Alexandre Courbot <gnurou@gmail.com>
CC: Simon Horman <horms@verge.net.au>
CC: Pratyush Anand <pratyush.anand@gmail.com>
CC: Michal Simek <michal.simek@xilinx.com>
CC: "Sören Brinkmann" <soren.brinkmann@xilinx.com>
CC: Sebastian Andrzej Siewior <bigeasy@linutronix.de>

We previously used of_get_named_gpio(), which ignores the OF flags cell, so
the reset GPIO defaulted to "active high." This doesn't work on the Toradex
Apalis SoM with Ixora base board, which has an active-low reset GPIO.

Use devm_gpiod_get_optional() instead so we pay attention to the active
high/low flag.  This also adds support for GPIOs described via ACPI.

[bhelgaas: changelog]
Signed-off-by: NPetr Štetiar <ynezz@true.cz>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: NLucas Stach <l.stach@pengutronix.de>

We are in a context where we can sleep, and the PCIe reset gpio may be on
an I2C expander.  Use the cansleep() variant when setting the GPIO value.

Based on a patch from Russell King for pci-mvebu.c.
Signed-off-by: NFabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: NLucas Stach <l.stach@pengutronix.de>

Add a #define for PCIE_PHY_RX_ASIC_OUT_VALID and use it instead of a
hardcoded value.

[bhelgaas: drop PCIE_PHY_DEBUG_R0_LTSSM_MASK; updated in future patch]
Signed-off-by: NFabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: NBjorn Helgaas <helgaas@kernel.org>
Reviewed-by: NLucas Stach <l.stach@pengutronix.de>