Re: [PATCH v4 2/5] i2c: qcom-cci: Support per-mode CCI clock rates

[Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>]

On 8/1/26 10:10 PM, Loic Poulain wrote:
> The CCI hw_params timing values (thigh, tlow, etc.) are expressed in
> clock ticks and are only valid at the specific CCI clock rate they were
> calibrated for. Different I2C modes may be calibrated for different
> rates, and the single CCI clock is shared by all masters.
> 
> Turn the timing table into a two-dimensional [rate][mode] matrix so a
> given rate can carry timing sets for each mode, and select the entry
> matching the currently running clock rate at init time. The existing
> per-variant values are moved under their calibrated rate (19.2 MHz for
> v1/v1.5, 37.5 MHz for v2), no timing values are changed.
> 
> At this stage the driver only validates the running rate against the
> table, the timings are only valid at the exact rate they were calibrated
> for, so if the current rate has no matching entry for a master's mode,
> fail initialization rather than program incorrect timings. A following
> patch actively enforces the required rate so this becomes a safety net.
> 
> Suggested-by: Vladimir Zapolskiy <vladimir.zapolskiy@linaro.org>
> Signed-off-by: Loic Poulain <loic.poulain@oss.qualcomm.com>
> ---

Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>

Konrad