On Sat, 21 Jan 2023 17:13:03 -0600 Samuel Holland samuel@sholland.org wrote:
Hi Samuel,
thanks for re-spinning this!
This series adds a driver for the regulators in X-Powers AXPxxx PMICs. It supports everything except regulators shared with GPIO pins. Those have a different register interface, so they may need a separate driver.
Regulator setup in U-Boot proper is needed for Ethernet and HDMI/LCD display output.
So I used a BL31 with SUNXI_SETUP_REGULATORS=0 on a Pine64, and with some tweaking of the .config, your HDMI series, my patch to parse phy-supply in sun8i-emac.c, and some delay after that, I could get both Ethernet and HDMI to work. So that seems to be working!
Given that this series does not enable this in any defconfig, I guess there is little risk in merging this. We can then bring this into wider circulation with defconfig/Kconfig patches, after a bit more testing. I am a bit uneasy seeing this code bringing up regulators/setting voltages that were disabled before, so my plan was to let people enable this on their boards manually and report back whether this works, then rolling this maybe by SoC, starting with the A64, maybe H6 (for our beloved OPi PC 3).
For some SoCs (H616), this driver could possibly be used for the DRAM regulator setup done in SPL. Older SoCs do all of their regulator setup in SPL. Some of that is probably necessary, but I think a lot of it is not and can be deferred to U-Boot proper or Linux; that's just where it was convenient to initialize the PMIC at the time.
I agree, it sounds quite beneficial to get rid of this ad-hoc SPL AXP setup we do for the older SoCs, but I guess we cannot defer everything to U-Boot proper without further rework. For instance we bump up DCDC2 on A20 to allow clocking the CPU higher, which is done in SPL, but could also wait. Anyway, it's indeed an optimisation for later, I guess we have bigger fish to fry first.
The main goal here is to replace the corresponding code in TF-A, both because of TF-A size constraints, and because the TF-A code is too simple/overzealous and breaks EPHY power sequencing on some boards.
I totally agree, and I would focus on the A64 and H6 for this reason first.
So I merged this series, should be part of the first PR for 2023.04.
Cheers, Andre
Changes in v2:
- Dual-license the driver
- Add a comment about the requirements for the voltage table
- Fix AXP22x ALDO3 enable bit position
Samuel Holland (3): power: pmic: axp: Provide a variant ID in the driver data power: regulator: Add a driver for AXP PMIC regulators power: pmic: axp: Bind regulators from the DT
drivers/power/pmic/axp.c | 36 ++- drivers/power/regulator/Kconfig | 14 ++ drivers/power/regulator/Makefile | 1 + drivers/power/regulator/axp_regulator.c | 312 ++++++++++++++++++++++++ include/axp_pmic.h | 12 + 5 files changed, 366 insertions(+), 9 deletions(-) create mode 100644 drivers/power/regulator/axp_regulator.c