doc: Documentation edits for 2.7.99-cs1 release

Added firmware bundle compatibility table.
Updated nRF54H20 GS guide.
Added initial power management documentation.
Added initial clock control documentation.
Migration notes for |NCS| v2.7.99-cs1 and the nRF54H20 DK.

Signed-off-by: Francesco Domenico Servidio <francesco.servidio@nordicsemi.no>

doc/nrf/app_dev/device_guides/nrf54h.rst

@@ -21,6 +21,19 @@ Zephyr and the |NCS| provide support and contain board definitions for developin
        | ``nrf54h20dk_nrf54h20_cpurad``
        | ``nrf54h20dk_nrf54h20_cpuppr``
 
+The following table indicates the compatibility between nRF54H20 firmware bundle versions and |NCS| versions:
+
+.. list-table::
+   :header-rows: 1
+
+   * - |NCS| version
+     - nRF54H20 firmware bundle version
+   * - v2.7
+     - v0.5.0
+   * - v2.7.99-cs1
+     - v0.6.2
+
+
 .. toctree::
    :maxdepth: 2
    :caption: Subpages:

doc/nrf/app_dev/device_guides/working_with_nrf/nrf54h/ug_nrf54h20_architecture.rst

@@ -21,3 +21,5 @@ The following pages briefly describe topics like the responsibilities of the cor
    ug_nrf54h20_architecture_ipc
    ug_nrf54h20_architecture_boot
    ug_nrf54h20_architecture_lifecycle
+   ug_nrf54h20_architecture_pm
+   ug_nrf54h20_architecture_clockman

doc/nrf/app_dev/device_guides/working_with_nrf/nrf54h/ug_nrf54h20_architecture_clockman.rst

@@ -0,0 +1,114 @@
+.. _ug_nrf54h20_architecture_clockman:
+
+nRF54H20 clock management
+#########################
+
+.. contents::
+   :local:
+   :depth: 2
+
+The nRF54H20 SoC consists of multiple asynchronous clock domains and requires clock sources for correct operation.
+Each of the clock sources needs proper management for the following reasons:
+
+* To start and stop the clock at the appropriate time.
+* To select the proper clock source.
+* To calibrate or synchronize the clock to a more accurate source.
+
+Some clock management operations are performed solely by hardware circuits, while others require software intervention.
+Most clocks can be locked to more accurate ones to improve their accuracy.
+
+
+Clock domains
+*************
+
+The nRF54H20 SoC consists of the following clock domains:
+
+* Low frequency clock (LFCLK)
+* High-frequency oscillator (HFXO)
+* FLL16M
+* Application Core HSFLL
+* Radio Core HSFLL
+* Secure Domain HSFLL
+* Global HSFLL
+
+Each clock domain is enabled independently of others, and it is automatically enabled when at least one sink is active.
+The firmware can choose to keep each clock domains enabled even when all its sinks are inactive.
+
+Clock domain sources are selected by ``clock_control`` drivers based on the clock parameter requirements reported by the software modules using the ``clock_control`` functions.
+These requirements can include clock frequency, accuracy, or precision.
+Some clock domains are configured by ``clock_control`` drivers using ``LRCCONF`` peripherals, while others are configured with the assistance of the System Controller Firmware.
+
+The application-facing APIs expose only the domain that directly clocks the component used by the application.
+The management of the clocks on which this domain depends is handled internally by the associated clock driver.
+
+For example, a firmware module might request better timing accuracy for a fast UART instance.
+In this case, the firmware module requests the accuracy from the global HSFLL device driver, which directly clocks the UART.
+The dependencies, such as FLL16M and LFXO, are managed internally by the global HSFLL driver, not directly by the firmware module.
+
+LFCLK
+=====
+
+The Low-Frequency Clock domain is responsible for generating a 32768 Hz clock signal for ultra-low-power peripherals like ``GRTC`` or ``RTC``.
+
+HFXO
+====
+
+The high-frequency crystal oscillator domain is responsible for clocking peripherals requiring high accuracy and MHz range frequency.
+The drawback of this clock source is relatively high power consumption so it is enabled only when needed.
+
+Hardware capabilities
+---------------------
+
+The HFXO, like any other clock domain, can be connected in hardware to one of the available sources.
+Additionally, it provides the clock signal to all of its sinks.
+
+FLL16M
+======
+
+The FLL16M clock domain clocks most of the peripherals in the system (*slow*, 16 MHz).
+Its accuracy results in the timing accuracy of slow ``UART``, ``SPI``, ``TWI``, ``PWM``, ``SAADC``, among others.
+
+Local HSFLLs
+============
+
+Local HSFLLs are clocking CPUs in local domains, fast peripherals around them, and local RAM.
+
+Global HSFLL
+============
+
+Global HSFLL clocks *fast* peripherals, FLPR, RAM, and MRAM blocks.
+
+Zephyr clock control API
+************************
+
+Zephyr RTOS contains a ``clock_control`` device driver class for managing clocks.
+The ``clock_control`` API is designed to support multiple requestors.
+Moreover, the ``clock_control`` API supports blocking or asynchronous operations based on notifications when the requested clock settings are applied.
+
+The ``clock_control`` subsystem exposes portable parameters in its functions, which include:
+
+* Accuracy requests in ppm values for all the clock domains.
+* Precision requests in enumerated high- and low-precision modes.
+* Frequency requests (clock rate) for the Application core HSFLL (all the other clock domains have fixed frequencies).
+
+When multiple modules request conflicting parameters from the same clock, the system prioritizes selecting the mode with minimal power consumption that satisfies all requests.
+For example, if a UART driver requests 100 ppm accuracy and a SPI driver requests 200 ppm accuracy, the system will choose a mode with 100 ppm accuracy or better, as it meets both requirements (100 ppm accuracy is better than 200 ppm) while optimizing power usage.
+This policy applies to all clock parameters, including frequency and precision, following these criteria:
+
+* The applied precision is at least as good as requested.
+* The applied frequency is at least as fast as requested.
+* All parameters are optimized for power consumption.
+
+For more details, see the following links:
+
+* :ref:`zephyr:clock_control_api`.
+* The following calls in the `Zephyr's nRF clock control API extensions`_ (:file:`include/zephyr/drivers/clock_control/nrf_clock_control.h`):
+
+  * ``nrf_clock_control_request()``: Requests a reservation to use a given clock with specified attributes.
+  * ``nrf_clock_control_release()``: Releases a reserved use of a clock.
+  * ``nrf_clock_control_cancel_or_release()``: Safely cancels a reservation request.
+
+* The following calls in the `clocks devicetree macro API`_ (:file:`include/zephyr/devicetree/clocks.h`):
+
+  * ``DT_CLOCKS_CTLR_BY_IDX()``: Gets the node identifier for the controller phandle from a *clocks* phandle-array property at an index.
+  * ``DT_CLOCKS_CTLR()``: It is equivalent to ``DT_CLOCKS_CTLR_BY_IDX()`` with index (idx) set to 0.

doc/nrf/app_dev/device_guides/working_with_nrf/nrf54h/ug_nrf54h20_architecture_pm.rst

@@ -0,0 +1,247 @@
+.. _ug_nrf54h20_architecture_pm:
+
+nRF54H20 Power Management
+#########################
+
+.. contents::
+   :local:
+   :depth: 2
+
+The nRF54H20 SoC is a distributed system where each domain tries to achieve minimal power consumption for itself.
+When all CPUs are ready to fully minimize power consumption by entering the System Off hardware state, the System Controller prepares the system and triggers the entrance in this state.
+
+Power states
+************
+
+The nRF54H20 ARM Cortex CPUs currently support the following software power states:
+
+* Active
+* Idle
+* Local suspend to Ram
+
+Overview
+********
+
+Each CPU in the nRF54H20 SoC tries to preserve as much power as possible, independently from other CPUs.
+The power management subsystem, operating independently within each CPU, continuously selects the most optimal power state based on the current conditions of the CPU.
+
+Power states details
+********************
+
+The following sections describes the details of each of the software power states available on the nRF54H20 SoC.
+
+Active
+======
+
+*Active* is the power state in which the CPU is actively processing.
+
+.. list-table::
+   :widths: auto
+
+   * - CPU
+     - Powered on and clocked.
+
+   * - RAM
+     - Banks used by the executed code are enabled.
+       Other banks may be in any state.
+
+   * - System state
+     - *System ON*
+
+   * - Peripherals
+     - All can be active.
+       The state of all inactive peripherals is retained in the hardware flip-flops.
+
+   * - Coprocessors
+     - All can be active.
+       The state of inactive coprocessors is retained according to their selected sleep state.
+
+   * - System timer (based on GRTC)
+     - Active
+
+This is the power state with the highest power consumption.
+The software execution latency is minimal.
+The primary source of latency is the wake-up of the ``MRAMC``.
+The maximum latency depends on the MRAM power state configured by the System Controller.
+
+Idle
+====
+
+*Idle* is the lightest sleep power state available in the system where the cache content is retained.
+
+.. list-table::
+   :widths: auto
+
+   * - CPU
+     - Powered on but suspended (not clocked).
+
+   * - RAM
+     - Banks used by the executed code are enabled.
+       Other banks may be in any state.
+
+   * - System state
+     - *System ON*
+
+   * - Peripherals
+     - All can be active.
+       The local peripherals are powered and preserve their state.
+       The state of inactive peripherals in other domains is retained in the hardware flip-flops.
+
+   * - Coprocessors
+     - All can be active.
+       The state of inactive coprocessors is retained according to their selected sleep state.
+
+   * - System timer (based on GRTC)
+     - Active
+
+The power consumption in this state is lower than in *Active*, but higher than in other power states.
+The wake-up latency is higher than in *Active*, but lower than in the other power states.
+The primary sources of wake-up latency are the wake-up of the ``MRAMC`` and the startup of clock sources.
+The maximum latency depends on the MRAM power state configured by the System Controller.
+
+Local Suspend to RAM
+********************
+
+*Local Suspend to RAM* is a sleep state that balances between power consumption and wake-up latency.
+
+This state is available only for DVFS-capable domains.
+Other domains, such as Radio, cannot retain the CPU and local peripherals in the *System ON (All) Idle* state.
+
+In this state, the entire local Active Power Domain, including the CPU, is unpowered.
+The state of the CPU and the peripherals powered by the local Active Power Domain is not retained by hardware flip-flops.
+Instead, their state is retained by software in RAM.
+
+.. list-table::
+   :widths: auto
+
+   * - CPU
+     - Unpowered.
+       Its state is retained in RAM.
+
+   * - RAM
+     - Enabled or retained depending on the hardware state.
+
+   * - System state
+     - * *System ON* if at least one other CPU or a peripheral clocked greater than 32 kHz is active.
+       * *System ON Idle* if all CPUs are disabled and the only active peripherals are clocked with 32 kHz (real-time part of ``GRTC``, ``RTC``, ``WDT``) or System Off wake-up sources.
+       * *System ON All Idle* if all other CPUs and all peripherals except System Off wake-up sources are disabled.
+
+       The hardware automatically selects one of these states based on the activity of other CPUs and peripherals.
+
+   * - Peripherals
+     - * Powered by the local Active Power Domain must be disabled.
+       * Powered by any other power domain can be active.
+
+       The state of the inactive peripherals located in other power domains is retained in the hardware flip-flops.
+
+       It is recommended to use only 32 kHz clocked peripherals in this state to allow entering *System ON Idle*.
+       One example could be using GPIO as CSN to wake up the system and enable an SPIS peripheral only after the system is woken up.
+
+   * - Coprocessors
+     - Global can be active.
+       There are no local coprocessors in the domains supporting this sleep state.
+       The state of inactive coprocessors is retained according to their selected sleep state.
+
+   * - System timer (based on GRTC)
+     - Active
+
+The power consumption in this state depends on the overall System state but is lower than in any of the *Idle* states.
+The wake-up latency is higher than in any of the *Idle* states due to the CPU state restoration procedure.
+
+Selecting the optimal power state
+*********************************
+
+In the nRF54H20 SoC, each local domain is responsible for selecting the power state that results in minimal power consumption while maintaining an acceptable level of performance.
+
+Entering a deeper sleep state leads to power savings when the system is idle, but it requires increased power consumption to enter and exit the sleep state.
+There is a minimum sleep duration that justifies the energy spent on entering and exiting a sleep state, and this duration varies for each sleep state.
+
+In the SoC, a local domain has full control over entering and exiting local sleep states, allowing it to assess whether entering these sleep states is optimal at any given moment.
+However, entering sleep states associated with system-off requires cooperation between local domains and the System Controller.
+Local domains have limited control over the time and energy required to enter or exit system-off, as well as the power consumption during system-off.
+
+Latency management
+******************
+
+The sources of wake-up latency in the nRF54H20 SoC can be categorized into two types: local and global.
+Each CPU is responsible for managing its latency sources, with local sources handled by local domains and global sources managed by the System Controller.
+
+Local cores are responsible for handling latencies caused by restoring the system from suspend-to-RAM states.
+Local cores schedule their wake-up in advance of expected events.
+The timing of expected events is reported to the power management subsystem in the RTOS by the software modules anticipating these events.
+The power management subsystem sets a ``GRTC`` channel in advance of the next expected event to compensate for local wake-up latency.
+
+The System Controller is responsible for handling latencies caused by restoring the system from the system-off state (the warm boot procedure latency).
+The System Controller schedules the system wake-up from the system-off state in advance of the next ``GRTC`` event to compensate for the warm-boot latency of the system.
+
+Because the warm-boot latency is compensated by the System Controller, from a local CPU's perspective, the latency when restoring from the local-off state and the system-off state is expected to be the same.
+
+Latency in local domains
+========================
+
+Any local software module (like a device driver) can anticipate events like ISRs.
+Some of these events have predictable timing, while others have unpredictable timing.
+Handling the latency of events with unpredictable timing is the same in both simple and complex systems.
+
+If handling an event with predictable timing requires restoring the state of the software module or the peripherals used by this module before the event is processed, the software module is responsible for scheduling a timer event in advance.
+This scheduled event is used to restore the state of the software module or peripherals.
+
+The Power Management subsystem in a local domain is responsible for scheduling a wake-up in advance to compensate for the domain's core state restoration latency from the local power state.
+The wake-up time scheduled in advance by the power management subsystem is combined with the advance time added by the software module.
+This approach ensures that the local domain and the software modules anticipating an event have sufficient time to fully restore before the event occurs, allowing the event to be handled without latency.
+
+Unretained hardware classification
+**********************************
+
+Some power states in the nRF54H20 SoC result in powering off certain peripherals.
+The state of these peripherals is not retained by hardware and must be restored by software before the peripheral is activated.
+
+See the following sections for the lists of peripheral groups and the related software modules responsible for restoring the peripheral's state for each group.
+
+Peripherals in local domains
+============================
+
+All local domains include a common set of hardware modules.
+In addition to these, most local domains also contain domain-specific peripherals.
+
+Common peripherals for all local domains
+----------------------------------------
+
+Each local domain contains a set of peripherals that are classified consistently across all local domains.
+The following table summarizes the active peripherals that need handling when exiting the *Local Suspend to RAM* state.
+
++---------------+--------------------+--------------------+--------------------+--------------------------+
+|Type           | List of the        | Source of data to  | Time of restoration| Software module          |
+|               | peripherals        | restore            |                    | responsible for restoring|
++===============+====================+====================+====================+==========================+
+|Active         | * ``MVDMA``        | Device driver's    | Decided by the     | The device driver        |
+|peripherals    |                    | code and data      | driver             |                          |
++---------------+--------------------+--------------------+--------------------+--------------------------+
+
+Peripherals specific to the Application Domain
+----------------------------------------------
+
+There are no peripherals specific to the Application Domain.
+
+Peripherals specific to the Secure Domain
+-----------------------------------------
+
+The Secure Domain contains additional peripherals that require handling in the *Local Suspend to RAM* state.
+
++---------------+--------------------+--------------------+--------------------+--------------------------+
+|Type           | List of the        | Source of data to  | Time of restoration| Software module          |
+|               | peripherals        | restore            |                    | responsible for restoring|
++===============+====================+====================+====================+==========================+
+|Active         | * ``CRACEN``       | Device driver's    | Decided by the     | The device driver        |
+|peripherals    |                    | code and data      | driver             |                          |
++---------------+--------------------+--------------------+--------------------+--------------------------+
+
+Peripherals specific to the Radio Domain
+----------------------------------------
+
+The Radio Domain does not implement the *Local Suspend to RAM* state.
+
+Power management benchmark
+**************************
+
+To benchmark the power consumption in *Idle* state, see :ref:`multicore_idle_test`.