Re: [PATCH v3 06/12] soc: qcom: geni-se: Introduce helper APIs for performance control

[Praveen Talari]

Hi Konrad

On 1/30/2026 5:53 PM, Konrad Dybcio wrote:
> On 1/12/26 11:47 AM, Praveen Talari wrote:
> > The GENI Serial Engine (SE) drivers (I2C, SPI, and SERIAL) currently
> > manage performance levels and operating points directly. This resulting
> > in code duplication across drivers. such as configuring a specific level
> > or find and apply an OPP based on a clock frequency.
> >
> > Introduce two new helper APIs, geni_se_set_perf_level() and
> > geni_se_set_perf_opp(), addresses this issue by providing a streamlined
> > method for the GENI Serial Engine (SE) drivers to find and set the OPP
> > based on the desired performance level, thereby eliminating redundancy.
> >
> > Signed-off-by: Praveen Talari <praveen.talari@xxxxxxxxxxxxxxxx>
> > ---
>
> [...]
>
> > +/**
> > + * geni_se_set_perf_level() - Set performance level for GENI SE.
> > + * @se: Pointer to the struct geni_se instance.
> > + * @level: The desired performance level.
> > + *
> > + * Sets the performance level by directly calling dev_pm_opp_set_level
> > + * on the performance device associated with the SE.
> > + *
> > + * Return: 0 on success, or a negative error code on failure.
> > + */
> > +int geni_se_set_perf_level(struct geni_se *se, unsigned long level)
> > +{
> > +	return dev_pm_opp_set_level(se->pd_list->pd_devs[DOMAIN_IDX_PERF], level);
> > +}
> > +EXPORT_SYMBOL_GPL(geni_se_set_perf_level);
>
> This function is never used

it will be used by UART driver, not for I2C/SPI.
> > +
> > +/**
> > + * geni_se_set_perf_opp() - Set performance OPP for GENI SE by frequency.
> > + * @se: Pointer to the struct geni_se instance.
> > + * @clk_freq: The requested clock frequency.
> > + *
> > + * Finds the nearest operating performance point (OPP) for the given
> > + * clock frequency and applies it to the SE's performance device.
> > + *
> > + * Return: 0 on success, or a negative error code on failure.
> > + */
> > +int geni_se_set_perf_opp(struct geni_se *se, unsigned long clk_freq)
>
> I think with the SPI driver in mind (which seems to do a simple rateset

APIs were added as generic interfaces shared across I²C/SPI which is 
specific to firmware control, not Linux control.

> for both backends) we could do:
>
> > +{
> > +	struct device *perf_dev = se->pd_list->pd_devs[DOMAIN_IDX_PERF];
>
> Then, we can do struct device * perf_dev = se->dev;
I don't think, it is needed since this is specific to firmware control, 
not Linux control.

Thanks,
Praveen Talari

> if (se->pd_list && se->pd_list->pd_devs[DOMAIN_IDX_PERF])
> 	perf_dev = se->pd_list->pd_devs[DOMAIN_IDX_PERF];
>
> and reuse it in both cases, completely transparently to the caller
>
> Konrad