[PATCH 0/5] Qualcomm CCI I2C clock requirements enforcement

Konrad Dybcio
2025-09-04T14:31:28Z

The hardware requires the faster of the two (37.5 MHz as opposed to
19.2 MHz) clock rates to hit the required timings for I2C Fast+ Mode.

Additionally, the magic presets for electrical tuning registers on SoCs
supporting that faster mode ("cci_v2" in the driver) are calculated
based on that faster frequency.

Moreover, while its unlikely that it would ever exhibit as an issue
given CCI is a slow & tiny core, we do need to express a minimal voltage
level for any given clock rate, which is where the (optional -
backwards compat) OPP table addition comes in.

This series helps ensure all these requirements are met.

Patch 1 is a related but independent fix, can be picked right away
Patch 5 can be functionally merged as-is, but depends on patch 2 for
bindings

Signed-off-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
---
Konrad Dybcio (5):
arm64: dts: qcom: sc8280xp: Fix CCI3 interrupt
dt-bindings: i2c: qcom-cci: Allow operating-points-v2
i2c: qcom-cci: Drop single-line wrappers
i2c: qcom-cci: Add OPP table support and enforce FAST_PLUS requirements
arm64: dts: qcom: sc8280xp: Add OPP table for CCI hosts

.../devicetree/bindings/i2c/qcom,i2c-cci.yaml | 2 +
arch/arm64/boot/dts/qcom/sc8280xp.dtsi | 16 +++++++-
drivers/i2c/busses/i2c-qcom-cci.c | 45 +++++++++++++++++-----
3 files changed, 52 insertions(+), 11 deletions(-)
---
base-commit: 4ac65880ebca1b68495bd8704263b26c050ac010
change-id: 20250904-topic-cci_updates-800fdc9bada4

Best regards,
--
Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>