[PATCH v3 00/15] Bring suspend to RAM support to PCIe Aardvark driver

[Miquel Raynal <miquel.raynal@bootlin.com>]

Hello,

As part of an effort to bring suspend to RAM support to Armada 3700
SoCs (main target: ESPRESSObin), this series handles the work around
the PCIe IP.

First, more configuration is done in the 'setup' helper as inspired
from the U-Boot driver. This is needed to entirely initialize the IP
during future resume operation (patch 1).

Then, reset GPIO, PHY and clock support are introduced (patch 2-4). As
current device trees do not provide the corresponding properties, not
finding one of these properties is not an error and just produces a
warning. However, if the property is present, an error during PHY
initialization will fail the probe of the driver.

Note: To be sure the clock will be resumed before this driver, a first
series adding links between clocks and consumers has been submitted,
see [1]. Anyway, having the clock series applied first is not needed.

Patch 5 adds suspend/resume hooks, re-using all the above.

Finally, bindings and device trees are updated to reflect the hardware
(patch 6-12). While the clock depends on the SoC, the reset GPIO and
the PHY depends on the board so the clock is added in the
armada-37xx.dtsi file while the two other properties are added in
armada-3720-espressobin.dts.

[1] http://lists.infradead.org/pipermail/linux-arm-kernel/2019-January/623885.html

Thanks,
Miquèl


Changes since v2:
=================
* Minor patches reordering.
* Added pinctrl patches from Gregory Clement fixing the PCIe pins. His
  changes implied modifications in the DT/bindings patches adding PCIe
  reset pin support.
* Added a new patch that enlarges the PIO timeout of the driver
  (explanations in the commit log).
* With the timeout changed, removed the "experimental delay" that was
  needed at resume time before accessing any register.

Changes since v1:
=================
* Change the capitalization in commit titles to follow the PCI
  subsystem rules.
* Added Suggested-by tag to the patch adding PHY support and to the
  patch adding the PHY property in the DT.
* Added Rob's Reviewed-by tags on bindings.
* I am following the discussion about calling functions that might
  sleep in a NOIRQ context. As there is no real problem yet (as per my
  understanding), I did not change anything on this regard.


Miquel Raynal (15):
  PCI: aardvark: Enlarge PIO timeout
  PCI: aardvark: Configure more registers in the configuration helper
  PCI: aardvark: Add clock support
  PCI: aardvark: Add PHY support
  PCI: aardvark: Add PCIe warm reset support
  PCI: aardvark: Add external reset GPIO support
  PCI: aardvark: Add suspend to RAM support
  dt-bindings: PCI: aardvark: Describe the clocks property
  dt-bindings: PCI: aardvark: Describe the PHY property
  dt-bindings: PCI: aardvark: Describe the PCIe endpoint card reset pins
  dt-bindings: PCI: aardvark: Describe the reset-gpios property
  ARM64: dts: marvell: armada-37xx: declare PCIe clock
  ARM64: dts: marvell: armada-3720-espressobin: declare PCIe PHY
  ARM64: dts: marvell: armada-37xx: declare PCIe reset pin
  ARM64: dts: marvell: armada-3720-espressobin: declare PCIe warm reset
    pin

 .../devicetree/bindings/pci/aardvark-pci.txt  |  14 ++
 .../dts/marvell/armada-3720-espressobin.dts   |   3 +
 arch/arm64/boot/dts/marvell/armada-37xx.dtsi  |  10 +
 drivers/pci/controller/pci-aardvark.c         | 217 +++++++++++++++++-
 4 files changed, 243 insertions(+), 1 deletion(-)

-- 
2.19.1