On Wed Oct 1, 2025 at 4:37 PM CEST, Markus Schneider-Pargmann (TI.com) wrote: > Hi, > > This series adds support for Partial-IO to the ti-sci driver, > implementing the firmware interface necessary to enter this low power > state. It processes the wakeup-source properties from the devicetree and > communicates with the system firmware to enter Partial-IO mode when > appropriate wakeup sources are enabled. > > Partial-IO Overview > ------------------ > Partial-IO is a low power system state in which nearly everything is > turned off except the pins of the CANUART group (mcu_mcan0, mcu_mcan1, > wkup_uart0 and mcu_uart0). These devices can trigger a wakeup of the > system on pin activity. Note that this does not resume the system as the > DDR is off as well. So this state can be considered a power-off state > with wakeup capabilities. > > A documentation can also be found in section 6.2.4 in the TRM: > https://www.ti.com/lit/pdf/spruiv7 > > Implementation Details > ---------------------- > The complete Partial-IO feature requires three coordinated series, each > handling a different aspect of the implementation: I missed updating the lore links, sorry, here are the new ones: > > 1. m_can driver series: Implements device-specific wakeup functionality > for m_can devices, allowing them to be set as wakeup sources. > https://gitlab.baylibre.com/msp8/linux/-/tree/topic/mcan-wakeup-source/v6.17?ref_type=heads > https://lore.kernel.org/r/20250812-topic-mcan-wakeup-source-v6-12-v8-0-6972a810d63b@baylibre.com v10: https://lore.kernel.org/r/20251001-topic-mcan-wakeup-source-v6-12-v10-0-4ab508ac5d1e@baylibre.com > 2. Devicetree series: Defines system states and wakeup sources in the > devicetree for am62, am62a and am62p. > https://gitlab.baylibre.com/msp8/linux/-/tree/topic/am62-dt-partialio/v6.17?ref_type=heads > https://lore.kernel.org/r/20250812-topic-am62-dt-partialio-v6-15-v2-0-25352364a0ac@baylibre.com v3: https://lore.kernel.org/r/20251001-topic-am62-dt-partialio-v6-15-v3-0-7095fe263ece@baylibre.com Best Markus > 3. This series (TI-SCI firmware): Implements the firmware interface to > enter Partial-IO mode when appropriate wakeup sources are enabled. > > Devicetree Bindings > ------------------- > This series depends on the dt-schema pull request that adds bindings for > system-idle-states and updates the binding for wakeup-source: > https://github.com/devicetree-org/dt-schema/pull/150 > > This is now merged. These new bindings allow the ti-sci driver to > identify devices that can act as wakeup sources for specific system > states like Partial-IO. > > 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/v6.17?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 > > These patches are tested on am62-lp-sk. > > Best, > Markus > > Previous versions "firmware: ti_sci: Partial-IO support": > v1: https://lore.kernel.org/lkml/20240523080225.1288617-1-msp@baylibre.com/ > v2: https://lore.kernel.org/lkml/20240729080101.3859701-1-msp@baylibre.com/ > v3: https://lore.kernel.org/r/20241012-topic-am62-partialio-v6-13-b4-v3-0-f7c6c2739681@baylibre.com > v4: https://lore.kernel.org/r/20241219-topic-am62-partialio-v6-12-b4-v4-0-1cb8eabd407e@baylibre.com > v5: https://lore.kernel.org/r/20250306-topic-am62-partialio-v6-12-b4-v5-0-f9323d3744a2@baylibre.com > v6: https://lore.kernel.org/r/20250421-topic-am62-partialio-v6-12-b4-v6-0-3b5cefab1339@baylibre.com > v7: https://lore.kernel.org/r/20250812-topic-am62-partialio-v6-12-b4-v7-0-ac10865c2d87@baylibre.com > > Previous versions "can: m_can: Add am62 wakeup support": > 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 > v6: https://lore.kernel.org/r/20241219-topic-mcan-wakeup-source-v6-12-v6-0-1356c7f7cfda@baylibre.com > > Changes in v8: > - Add a patch to remove constant 0 argument passing to > ti_sci_cmd_prepare_sleep > - Move partial-io functions further up in the file before the first > static const initializations > > Changes in v7: > - Rebase to v6.17-rc1 > - Update the idle-state-name used to off-wake as introduced in > dt-schema > > Changes in v6: > - Narrowed down the wakeup-source binding to phandle lists > - Split off the mcan and DT changes into separate series > > Changes in v5: > - Rebased to v6.14-rc1 > - Merged m_can and ti_sci series to avoid conflicts and show > dependencies more easily > - Added definitions of system-states for am62/am62a/am62p > - Moved wakeup-source definitions into board dts files as they require > a bit of support on the board. > - Updated ti_sci support to walk through the wakeup-source phandle > lists > - Added pinctrl settings for mcu_mcan0/1 on all boards > - Minor style updates for ti_sci support for transfers without response > - Update and move the dt-binding for wakeup-source from the m_can > binding to the dt-schema repository > > Changes in v4: > - Rebased to v6.13-rc1 > - Removed all regulator related structures from patches and implemented > the wakeup-source property use instead. > > Changes in v3: > - Remove other modes declared for PREPARE_SLEEP as they probably won't > ever be used in upstream. > - Replace the wait loop after sending PREPARE_SLEEP with msleep and do > an emergency_restart if it exits > - Remove uarts from DT wakeup sources > - Split no response handling in ti_sci_do_xfer() into a separate patch > and use goto instead of if () > - Remove DT binding parital-io-wakeup-sources. Instead I am modeling > the devices that are in the relevant group that are powered during > Partial-IO with the power supplies that are externally provided to > the SoC. In this case they are provided through 'vddshv_canuart'. All > devices using this regulator can be considered a potential wakeup > source if they are wakeup capable and wakeup enabled. > - Added devicetree patches adding vcc_3v3_sys regulator and > vddshv_canuart for am62-lp-sk > - Add pinctrl entries for am62-lp-sk to add WKUP_EN for mcu_mcan0 and > mcu_mcan1 > > Changes in v2: > - Rebase to v6.11-rc1 > - dt-binding: > - Update commit message > - Add more verbose description of the new binding for a better > explanation. > - ti_sci driver: > - Combine ti_sci_do_send() into ti_sci_do_xfer and only wait on a > response if a flag is set. > - On failure to enter Partial-IO, do emergency_restart() > - Add comments > - Fix small things > > Signed-off-by: Markus Schneider-Pargmann (TI.com) > --- > Markus Schneider-Pargmann (TI.com) (3): > firmware: ti_sci: Remove constant 0 function arguments > firmware: ti_sci: Support transfers without response > firmware: ti_sci: Partial-IO support > > drivers/firmware/ti_sci.c | 154 ++++++++++++++++++++++++++++++++++++++++++---- > drivers/firmware/ti_sci.h | 5 ++ > 2 files changed, 146 insertions(+), 13 deletions(-) > --- > base-commit: 24c4d4041c2ec11c47baf6ea54f9379cf88809fc > change-id: 20241008-topic-am62-partialio-v6-12-b4-c273fbac4447 > prerequisite-change-id: 20241009-topic-mcan-wakeup-source-v6-12-8c1d69931bd8:v10 > prerequisite-patch-id: 40ff771d13dccae91c04ab120aa1b5e406b66e47 > prerequisite-patch-id: 830b339ea452edd750b04f719da91e721be630cb > prerequisite-patch-id: 2c9142d2bc47e64c49b7b8a7ca20a62a0be14870 > prerequisite-patch-id: aa64f7e9fcc3fcbb3cb871a05a07f398f3aa8231 > prerequisite-change-id: 20250415-topic-am62-dt-partialio-v6-15-327dd1ff17da:v3 > prerequisite-patch-id: 707e4619d7b844e1b67ccde28b4484b7b0d27daa > prerequisite-patch-id: 412feb5d3fc125e489d11b726c0b2d8fd5ff36f3 > prerequisite-patch-id: 4e3ed635267f9548b9ac7a9e440971bb1e54a5ee > prerequisite-patch-id: 65704d9da41da1fa9fc647c185f412022a16acb5 > prerequisite-patch-id: 95a62b97efdac9bdf1921c1222acefac6e608c84 > prerequisite-patch-id: 87d82194bc278580ae54e8788b4508f743c61061 > > Best regards,