[PATCH v2 0/5] Add OPP_LOW support for J7200

[Aniket Limaye]

This series adds OPP_LOW spec data in k3_avs driver and enables a config
option to select the OPP_LOW performance point.

J7200 SOC supports OPP_LOW and OPP_NOM as two Operating Performance
Points as per (7.5 Operating Performance Points) section in the
Datasheet [0].
- A72SS/MSMC at 2 GHz/1GHz operation must use OPP_NOM.
- A72SS/MSMC at 1 GHz/500 MHz operation can use OPP_NOM or OPP_LOW
  voltage (though OPP_LOW voltage is recommended to reduce power
  consumption).

The actual OPP voltage for the device is read from the efuse and
updated in k3_avs_probe().

The default j7200 devicetree and k3_avs driver set OPP_NOM spec
frequency and voltage.

In the board init file, if K3_OPP_LOW config is enabled, Check if
OPP_LOW AVS voltage read from efuse is valid and update frequency (A72
and MSMC) and voltage (VDD_CPU) as per the OPP_LOW spec.

[0]: https://www.ti.com/lit/gpn/dra821u  (J7200 Datasheet)

Test logs: https://gist.github.com/aniket-l/ec76679ebcb399cf10426bd7a4a154c3
With series applied on master plus below:
- CONFIG_K3_OPP_LOW enabled in config
- Additional helpful prints added in code
- Logs shown with and without efuse register programmed for OPP_0
  (Errors out if OPP_0 not found, programs OPP_LOW spec if found)

---
v2:
* Neha
- Fix indentation
- Updates to commit msgs

- Re-format patches 3/5 and 4/5 with logical changes in each patch

- Link to v1: https://lore.kernel.org/u-boot/20241017062911.2241167-1-a-limaye@ti.com/

Reid Tonking (5):
  arm: dts: k3-j7200-r5-common: Add msmc clk to a72 node
  misc: k3_avs: Add OPP_LOW voltage and frequency to vd_data
  misc: k3_avs: Check validity of efuse voltage data
  arm: mach-k3: j721e-init.c: J7200: Add support for CONFIG_K3_OPP_LOW
  configs: j7200_evm_r5_defconfig: Define K3_OPP_LOW

 .../arm/dts/k3-j7200-r5-common-proc-board.dts | 10 ++---
 arch/arm/mach-k3/Kconfig                      |  6 +++
 arch/arm/mach-k3/j721e/j721e_init.c           | 45 ++++++++++++++++++-
 configs/j7200_evm_r5_defconfig                |  1 +
 drivers/misc/k3_avs.c                         | 34 ++++++++++++++
 include/k3-avs.h                              |  2 +
 6 files changed, 92 insertions(+), 6 deletions(-)

-- 
2.34.1