Re: [PATCH 7/7] i2c: qcom-geni: Use geni_se_set_rate() for setting source clock frequency

[Praveen Talari]

Hi Mukesh

On 24-08-2026 19:11, Mukesh Savaliya wrote:
> On 8/5/2026 1:27 AM, Praveen Talari wrote:
> > On the SA8255P platform there is no Linux clock handler for the SE 
> > source
> > clock; resources are instead managed by firmware via a genpd performance
> > domain. The I2C driver therefore relies on geni_se_set_rate() to 
> > apply the
> > fixed 19.2 MHz source clock frequency expected by the SCL divider and
>
> somewhere it's 32 MHz also and this may change too ?
19.2 MHz is just the frequency currently requested by the I2C driver.

Other frequencies such as 32 MHz are also supported and may change in 
the future.
> > counter values programmed by qcom_geni_i2c_conf().
> >
> > Call geni_se_set_rate() directly from qcom_geni_i2c_conf() so the
> > configured frequency is applied to the correct device (the perf domain
> > device on the firmware-managed path, or se->dev otherwise) without 
> > the I2C
> > driver needing to know which resources_init() variant is in use.
> >
> > Drop the now-unused set_rate field from struct geni_i2c_desc, the
> > geni_se_set_perf_opp() usage on the SA8255P variant, and the unused freq
> > parameter from qcom_geni_i2c_conf().
> >
> > Signed-off-by: Praveen Talari <praveen.talari@xxxxxxxxxxxxxxxx>
> > ---
> >   drivers/i2c/busses/i2c-qcom-geni.c | 13 +++++++------
> >   1 file changed, 7 insertions(+), 6 deletions(-)
> >
> > diff --git a/drivers/i2c/busses/i2c-qcom-geni.c 
> > b/drivers/i2c/busses/i2c-qcom-geni.c
> > index a23554d101fd..4561e2d235d5 100644
> > --- a/drivers/i2c/busses/i2c-qcom-geni.c
> > +++ b/drivers/i2c/busses/i2c-qcom-geni.c
> > @@ -213,11 +213,11 @@ static int geni_i2c_clk_map_idx(struct 
> > geni_i2c_dev *gi2c)
> >       return -EINVAL;
> >   }
> >   -static int qcom_geni_i2c_conf(struct geni_se *se, unsigned long freq)
> > +static int qcom_geni_i2c_conf(struct geni_se *se)
> >   {
> >       struct geni_i2c_dev *gi2c = dev_get_drvdata(se->dev);
> >       const struct geni_i2c_clk_fld *itr = gi2c->clk_fld;
> > -    u32 val;
> > +    u32 val, ret;
> >         writel_relaxed(0, gi2c->se.base + SE_GENI_CLK_SEL);
> >   @@ -233,6 +233,10 @@ static int qcom_geni_i2c_conf(struct geni_se 
> > *se, unsigned long freq)
> >                    itr->clk_div, itr->t_high_cnt,
> >                    itr->t_low_cnt, itr->t_cycle_cnt);
> >   +    ret = geni_se_set_rate(&gi2c->se, 19200000);
>
> hard code ?
Good point. The 19.2 MHz value is not intended to be a permanent 
limitation.
This matches the frequency currently used by the I2C driver and 
therefore preserves
the existing behavior. If support for higher source clock frequencies 
(e.g. 32 MHz or others)
is added in the future, the requested OPP/performance state will need to 
be updated accordingly.
> May work currently, but if higher frequency support added, source may 
> change.
>
> Also you have added in commit message, but add a comment also here.
>
> > +    if (ret)
> > +        return ret;
> > +
> >       return geni_icc_set_bw_ab(&gi2c->se, GENI_DEFAULT_BW, 
> > GENI_DEFAULT_BW,
> >                     Bps_to_icc(gi2c->clk_freq_out));
> >   }
>
> [...]