PCI: dwc: Constify dw_pcie_host_ops structures ...

Port of a Linux commit 4ab2e7c

  The dw_pcie_host_ops structures are never modified.  Constify these
  structures such that these can be write-protected.

  Signed-off-by: Jisheng Zhang <jszhang@marvell.com>
  Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
  Acked-by: Jingoo Han <jingoohan1@gmail.com>
  Acked-by: Kishon Vijay Abraham I <kishon@ti.com>

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

PCI: dwc: designware: Handle ->host_init() failures ...

Port of a Linux commit 4a30176

  In several dwc-based drivers, ->host_init() can fail, so make sure to
  propagate and handle this to avoid continuing operation of a driver or
  hardware in an invalid state.

  Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
  Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
  Acked-by: Joao Pinto <jpinto@synopsys.com>
  Acked-by: Jingoo Han <jingoohan1@gmail.com>

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

PCI: Add SPDX GPL-2.0 to replace GPL v2 boilerplate ...

Port of a Linux commit 8cfab3c

  Add SPDX GPL-2.0 to all PCI files that specified the GPL version 2 license.

  Remove the boilerplate GPL version 2 language, relying on the assertion in
  b24413180f56 ("License cleanup: add SPDX GPL-2.0 license identifier to
  files with no license") that the SPDX identifier may be used instead of the
  full boilerplate text.

  Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
  Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

PCI: dwc: all: Split struct pcie_port into host-only and core structures ...

Port of a Linux commit 442ec4c

  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: Kishon Vijay Abraham I <kishon@ti.com>
  Signed-off-by: Bjorn 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>

For convenience sake, commit c046406

  PCI: dwc: Fix crashes seen due to missing assignments

  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-g9e31489 #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: 442ec4c04d12 ("PCI: dwc: all: Split struct pcie_port into host-only and core structures")
  Signed-off-by: Guenter Roeck <linux@roeck-us.net>
  Signed-off-by: Vivek Gautam <vivek.gautam@codeaurora.org>  # designware-plat
  Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
  Acked-by: Kishon Vijay Abraham I <kishon@ti.com>

was squashed into this one as well.

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

PCI: imx6: Remove LTSSM disable workaround ...

Port of a Linux commit a712807

  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: Lucas Stach <l.stach@pengutronix.de>
  Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

LTSSM disable workaround still needs to be performed before passing
control to Linux. However, in order to avoid the hang described above,
we move it to imx6_pcie_remove() and apply it without relying on
values in GPR.

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

PCI: imx6: Remove redundant "Link never came up" message ...

Port of a Linux commit caf3f56

  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: Fabio Estevam <fabio.estevam@nxp.com>
  Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
  Reviewed-by: Lucas Stach <l.stach@pengutronix.de>

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

PCI: imx6: Add DT property for link gen, default to Gen1 ...

Port of a Linux commit a5fcec4

  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/453209

  Signed-off-by: Tim Harvey <tharvey@gateworks.com>
  Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
  Reviewed-by: Lucas 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>

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

PCI: imx6: Factor out ref clock enable ...

Port of a Linux commit 4d1821e

  Factor out ref clock enable to make it cleaner to add imx6sx support.  No
  functional change intended.

  Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
  Tested-by: Christoph Fritz <chf.fritz@googlemail.com>

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

PCI: imx6: Remove unused return values ...

Port of a Linux commit 9ab021b

  Remove unused return values.  No functional change intended.

  Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

PCI: imx6: Port error messages for imx6_pcie_deassert_core_reset() ...

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

PCI: imx6: Reorder struct imx6_pcie ...

Port of a Linux commit 916bf1c

  Reorder struct imx6_pcie to put generic fields first.  No functional change
  intended.

  Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

PCI: imx6: Use generic DesignWare accessors ...

Port of a Linux commit 2a6a85d

  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: Bjorn Helgaas <bhelgaas@google.com>

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

PCI: imx6: Pass device-specific struct to internal functions ...

Port of a Linux commit e7d7705

   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: Bjorn Helgaas <bhelgaas@google.com>

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

PCI: imx6: Pass struct imx6_pcie to PHY accessors ...

Port of a Linux commit 8bad7f2

  Pass the struct imx6_pcie pointer, not dbi_base address, to PHY accessors.
  This enables future simplifications.  No functional change intended.

  Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

PCI: imx6: Removed unused struct imx6_pcie.mem_base ...

Port of a Linux commit 51c8470

  PCI: imx6: Removed unused struct imx6_pcie.mem_base

  Removed the unused struct imx6_pcie.mem_base member.  No functional change
  intended.

  Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

PCI: imx6: Add local struct device pointers ...

Port of a Linux commit 1395765

  Use a local "struct device *dev" for brevity and consistency with other
  drivers.  No functional change intended.

  Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

PCI: dwc: designware: Move register defines to designware header file ...

Port of a Linux commmit b90dc39

  No functional change. Move the register defines and other macros from
  pcie-designware.c to pcie-designware.h. This is in preparation to split the
  pcie-designware.c file into designware core file and host-specific file.

  While at that also fix a checkpatch warning.

  Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
  Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
  Reviewed-By: Joao Pinto <jpinto@synopsys.com>

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

PCI: designware: Add generic dw_pcie_wait_for_link() ...

Port of Linux commit 886bc5c

  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: Joao Pinto <jpinto@synopsys.com>
  Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
  Acked-by: Pratyush Anand <pratyush.anand@gmail.com>

NOTE: For some reason, all of the changes to imx6_pcie_wait_for_link()
made in 4d107d3 are actually not
present 886bc5c. So there isn't
really a kernel commit corresponding to removal of the large comment
block or check for !(reg & PCIE_PHY_DEBUG_R1_XMLH_LINK_IN_TRAINING)

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

PCI: imx6: Move link up check into imx6_pcie_wait_for_link() ...

Port of a Linux commit 4d107d3

  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 f95d3ae77191]
  Link: https://bugzilla.kernel.org/show_bug.cgi?id=100031
  Fixes: f95d3ae77191 ("PCI: imx6: Wait for retraining")
  Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
  Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

remove checks for xzalloc() returning NULL ...

xzalloc() either returns memory or panics, so checking for NULL is useless.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

PCI: imx6: Add DT bindings to configure PHY Tx driver settings ...

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.

[Andrey Smirnov: port to Barebox codebase]

Signed-off-by: Justin Waters <justin.waters@timesys.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Acked-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

PCI: imx6: Remove broken Gen2 workaround ...

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.

[Andrey Smirnov: port to Barebox codebase]

Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

PCI: imx6: Move PHY reset into imx6_pcie_establish_link() ...

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.

[Andrey Smirnov: port to Barebox codebase]

Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

PCI: imx6: Move imx6_pcie_reset_phy() near other PHY handling functions ...

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.

[Andrey Smirnov: port to Barebox codebase]

Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

PCI: imx6: Simplify a trivial if-return sequence ...

Simplify a trivial if-return sequence by combining it with a preceding
function call.

The semantic patch that makes this change is available in
scripts/coccinelle/misc/simple_return.cocci.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

PCI: imx6: Rename imx6_pcie_start_link() to imx6_pcie_establish_link() ...

Rename imx6_pcie_start_link() to imx6_pcie_establish_link() to follow the
convention of other DesignWare-based host drivers.  No functional change.

[Andrey Smirnov: port to BB codebase]
Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Pratyush Anand <pratyush.anand@gmail.com>
Acked-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

PCI: imx6: Add proper i.MX6+ reset sequence ...

I.MX6+ version of the silicon exposed PCIe core's reset signal as a bit
in one of the control registers. As a result using old, pre-i.MX6+,
reset sequence on i.MX6+ leads to Barebox hanging during startup. Using
exposed reset bit instead solves the problem.

This commit is based on portions of commit

c34068d

in http://git.freescale.com/git/cgit.cgi/imx/linux-2.6-imx.git

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Acked-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

PCI: imx6: Simplify imx6_pcie_remove() ...

Instead of manualy flipping the bits call imx6_pcie_assert_core_reset()
to give the code, executing after BB, a clean slate. This also makes the
function match similar code in Linux kernel driver.

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Acked-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

driver: replace dev_request_mem_region with dev_request_mem_resource ...

dev_request_mem_region doesn't work properly one some SoCs on which
PTR_ERR() values clash with valid return values from dev_request_mem_region.
Replace them with dev_request_mem_resource where possible.

This patch has been generated with the following semantic patch:

// <smpl>
@@
expression d;
expression n;
expression io;
identifier func;
@@
func(...) {
+struct resource *iores;
<+...
-io = dev_request_mem_region(d, n);
-if (IS_ERR(io)) {
+iores = dev_request_mem_resource(d, n);
+if (IS_ERR(iores)) {
...
-	return PTR_ERR(io);
-}
+	return PTR_ERR(iores);
+}
+io = IOMEM(iores->start);
...+>
}

@@
expression d;
expression n;
expression io;
identifier func;
@@
func(...) {
+struct resource *iores;
<+...
-io = dev_request_mem_region(d, n);
-if (IS_ERR(io)) {
+iores = dev_request_mem_resource(d, n);
+if (IS_ERR(iores))
-	return PTR_ERR(io);
-}
+	return PTR_ERR(iores);
+io = IOMEM(iores->start);
...+>
}

@@
expression d;
expression n;
expression io;
identifier func;
@@
func(...) {
+struct resource *iores;
<+...
-io = dev_request_mem_region(d, n);
-if (IS_ERR(io)) {
-	ret = PTR_ERR(io);
+iores = dev_request_mem_resource(d, n);
+if (IS_ERR(iores)) {
+	ret = PTR_ERR(iores);
...
}
+io = IOMEM(iores->start);
...+>
}

@@
expression d;
expression n;
expression io;
identifier func;
@@
func(...) {
+struct resource *iores;
<+...
-io = dev_request_mem_region(d, n);
+iores = dev_request_mem_resource(d, n);
+if (IS_ERR(iores))
+	return PTR_ERR(iores);
+io = IOMEM(iores->start);
...+>
}

@@
identifier func;
@@
func(...) {
<+...
struct resource *iores;
-struct resource *iores;
...+>
}
// </smpl>

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

PCI: imx6: properly shut down core when leaving barebox ...

As the i.MX6 PCIe core doesn't have a software reachable reset
wired up, it's hard for any driver to get the core into a known
good state.

To make it easier for whatever software follows barebox, bring
back the core into a safe state before leaving barebox.

Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>