[PATCH v6 0/7] can: m_can: Add am62 wakeup support

[Markus Schneider-Pargmann <msp@baylibre.com>]

Hi,

Series
------
am62, am62a and am62p support Partial-IO, a poweroff SoC state with a
few pin groups being active for wakeup.

To support mcu_mcan0 and mcu_mcan1 wakeup for the mentioned SoCs, the
series introduces a notion of wake-on-lan for m_can. If the user decides
to enable wake-on-lan for a m_can device, the device is set to wakeup
enabled. A 'wakeup' pinctrl state is selected to enable wakeup flags for
the relevant pins. If wake-on-lan is disabled the default pinctrl is
selected.

After feedback from Nishanth and Krzysztof, I moved to a wakeup-source
property that can be a list of powerstates in which the device is wakeup
capable. This describes special cases like Partial-IO where the device
is powered off but pins can be sensible to changes and trigger a wakeup.

It is based on v6.13-rc1.

Partial-IO
----------
This series is part of a bigger topic to support Partial-IO on am62,
am62a and am62p. Partial-IO is a poweroff state in which some pins are
able to wakeup the SoC. In detail MCU m_can and two serial port pins can
trigger the wakeup.
A documentation can also be found in section 6.2.4 in the TRM:
  https://www.ti.com/lit/pdf/spruiv7

This other series is relevant for the support of Partial-IO:

 - firmware: ti_sci: Partial-IO support
   https://gitlab.baylibre.com/msp8/linux/-/tree/topic/am62-partialio/v6.13?ref_type=heads

Testing
-------
A test branch is available here that includes all patches required to
test Partial-IO:

https://gitlab.baylibre.com/msp8/linux/-/tree/integration/am62-partialio/v6.13?ref_type=heads

After enabling Wake-on-LAN the system can be powered off and will enter
the Partial-IO state in which it can be woken up by activity on the
specific pins:
    ethtool -s can0 wol p
    ethtool -s can1 wol p
    poweroff

I tested these patches on am62-lp-sk.

Best,
Markus

Previous versions:
 v1: https://lore.kernel.org/lkml/20240523075347.1282395-1-msp@baylibre.com/
 v2: https://lore.kernel.org/lkml/20240729074135.3850634-1-msp@baylibre.com/
 v3: https://lore.kernel.org/lkml/20241011-topic-mcan-wakeup-source-v6-12-v3-0-9752c714ad12@baylibre.com
 v4: https://lore.kernel.org/r/20241015-topic-mcan-wakeup-source-v6-12-v4-0-fdac1d1e7aa6@baylibre.com
 v5: https://lore.kernel.org/r/20241028-topic-mcan-wakeup-source-v6-12-v5-0-33edc0aba629@baylibre.com

Changes in v6:
 - Rebased to v6.13-rc1
 - After feedback of the other Partial-IO series, I updated this series
   and removed all use of regulator-related patches.
 - wakeup-source is now not only a boolean property but can also be a
   list of power states in which the device is wakeup capable.

Changes in v5:
 - Make the check of wol options nicer to read

Changes in v4:
 - Remove leftover testing code that always returned -EIO in a specific
 - Redesign pincontrol setup to be easier understandable and less nested
 - Fix missing parantheses around wol_enable expression
 - Remove | from binding description

Changes in v3:
 - Rebase to v6.12-rc1
 - Change 'wakeup-source' to only 'true'
 - Simplify m_can_set_wol by returning early on error
 - Add vio-suuply binding and handling of this optional property.
   vio-supply is used to reflect the SoC architecture and which power
   line powers the m_can unit. This is important as some units are
   powered in special low power modes.

Changes in v2:
 - Rebase to v6.11-rc1
 - Squash these two patches for the binding into one:
   dt-bindings: can: m_can: Add wakeup-source property
   dt-bindings: can: m_can: Add wakeup pinctrl state
 - Add error handling to multiple patches of the m_can driver
 - Add error handling in m_can_class_allocate_dev(). This also required
   to add a new patch to return error pointers from
   m_can_class_allocate_dev().

Signed-off-by: Markus Schneider-Pargmann <msp@baylibre.com>
---
Markus Schneider-Pargmann (6):
      dt-bindings: can: m_can: Add wakeup properties
      can: m_can: Map WoL to device_set_wakeup_enable
      can: m_can: Return ERR_PTR on error in allocation
      can: m_can: Support pinctrl wakeup state
      arm64: dts: ti: k3-am62: Mark mcu_mcan0/1 as wakeup-source
      arm64: dts: ti: k3-am62a-mcu: Mark mcu_mcan0/1 as wakeup-source

Vibhore Vardhan (1):
      arm64: dts: ti: k3-am62p-mcu: Mark mcu_mcan0/1 as wakeup-source

 .../devicetree/bindings/net/can/bosch,m_can.yaml   |  27 +++++
 arch/arm64/boot/dts/ti/k3-am62-mcu.dtsi            |   2 +
 arch/arm64/boot/dts/ti/k3-am62a-mcu.dtsi           |   2 +
 .../boot/dts/ti/k3-am62p-j722s-common-mcu.dtsi     |   2 +
 drivers/net/can/m_can/m_can.c                      | 111 ++++++++++++++++++++-
 drivers/net/can/m_can/m_can.h                      |   4 +
 drivers/net/can/m_can/m_can_pci.c                  |   4 +-
 drivers/net/can/m_can/m_can_platform.c             |   4 +-
 drivers/net/can/m_can/tcan4x5x-core.c              |   4 +-
 9 files changed, 151 insertions(+), 9 deletions(-)
---
base-commit: 40384c840ea1944d7c5a392e8975ed088ecf0b37
change-id: 20241009-topic-mcan-wakeup-source-v6-12-8c1d69931bd8

Best regards,
-- 
Markus Schneider-Pargmann <msp@baylibre.com>