drivers/firmware/ti_sci.c | 154 ++++++++++++++++++++++++++++++++++++++++++---- drivers/firmware/ti_sci.h | 5 ++ 2 files changed, 146 insertions(+), 13 deletions(-)
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:
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
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
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) <msp@baylibre.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,
--
Markus Schneider-Pargmann (TI.com) <msp@baylibre.com>
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) <msp@baylibre.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,
On 16:37-20251001, 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: > > 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 > > 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 > > 3. This series (TI-SCI firmware): Implements the firmware interface to > enter Partial-IO mode when appropriate wakeup sources are enabled. If this is the order of dependencies, I guess the series has to wait till CAN driver changes are merged? did I get that right? Also surprised that the DT series is second in the dependency.. usually dts changes occur the last. but anyways.. [...] -- Regards, Nishanth Menon Key (0xDDB5849D1736249D) / Fingerprint: F8A2 8693 54EB 8232 17A3 1A34 DDB5 849D 1736 249D https://ti.com/opensource
Hi Nishanth, On Wed Oct 1, 2025 at 7:00 PM CEST, Nishanth Menon wrote: > On 16:37-20251001, 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: >> >> 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 >> >> 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 >> >> 3. This series (TI-SCI firmware): Implements the firmware interface to >> enter Partial-IO mode when appropriate wakeup sources are enabled. > > If this is the order of dependencies, I guess the series has to wait > till CAN driver changes are merged? did I get that right? Yes, the series has to wait for the m_can series as it containts the dt-binding required for this series to work. > > Also surprised that the DT series is second in the dependency.. usually > dts changes occur the last. but anyways.. Yes, true, they could be switched as well. The driver changes of course won't work as long as the DT series is not merged, but they could be merged in parallel as well. Neither the DT series nor this series modify any bindings. Only the mcan series does. Best Markus
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