On Thu, Oct 10, 2013 at 12:10:53PM +0100, Chanwoo Choi wrote:
> On 10/10/2013 07:28 PM, Mark Rutland wrote:
> > On Thu, Oct 10, 2013 at 02:41:35AM +0100, Chanwoo Choi wrote:
> >> This patch parse 'buck[2-4]_ramp_enable and buck_ramp_delay' platform data
> >> from dts file.
> >
> > Why?
> >
> > What do these describe? Why do we need them?
>
> Turn on ramp control of buck2/3/4.
Ok, but why does this need to be in the dt?
>
> >
> >>
> >> Signed-off-by: Chanwoo Choi <cw00.choi@xxxxxxxxxxx>
> >> Signed-off-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx>
> >> ---
> >> drivers/regulator/s5m8767.c | 16 ++++++++++++++++
> >> 1 file changed, 16 insertions(+)
> >>
> >> diff --git a/drivers/regulator/s5m8767.c b/drivers/regulator/s5m8767.c
> >> index c24448b..cb6cdb3 100644
> >> --- a/drivers/regulator/s5m8767.c
> >> +++ b/drivers/regulator/s5m8767.c
> >> @@ -640,6 +640,22 @@ static int s5m8767_pmic_dt_parse_pdata(struct platform_device *pdev,
> >> return -EINVAL;
> >> }
> >>
> >> + if (of_get_property(pmic_np, "s5m8767,pmic-buck2-ramp-enable", NULL))
> >> + pdata->buck2_ramp_enable = true;
> >
> > Please describe what this is and why we need it.
>
> buck2/3/4_ramp_enable is used to protect the chip from the in-rush current.
Ok. Could we not always set these in the driver? Under what
circumstances do we need this?
>
> >
> > For reading boolean proeprties, use of_property_read_bool.
>
> I'll fix it.
>
> >
> >> +
> >> + if (of_get_property(pmic_np, "s5m8767,pmic-buck3-ramp-enable", NULL))
> >> + pdata->buck3_ramp_enable = true;
> >> +
> >> + if (of_get_property(pmic_np, "s5m8767,pmic-buck4-ramp-enable", NULL))
> >> + pdata->buck4_ramp_enable = true;
> >> +
> >> + if (pdata->buck2_ramp_enable || pdata->buck3_ramp_enable
> >> + || pdata->buck4_ramp_enable) {
> >> + if (of_property_read_u32(pmic_np, "s5m8767,pmic-buck-ramp-delay",
> >> + &pdata->buck_ramp_delay))
> >> + pdata->buck_ramp_delay = 0;
> >
> > Why not initialise pdata->buck_ramp_delay to 0 beforehand?
> >
> > That way you don't need to check the return value of
> > of_property_read_u32 here.
> >
> > I note that pdata->buck_ramp_delay is an int, not a u32. Please use a
> > u32 temporary variable.
>
> I'll fix it
>
> >
> >> + }
> >> +
> >
> > NAK. None of these seem to be documented in mainline's
> > Documentation/devicetree/bindings/regulator/s5m8767-regulator.txt, nor
> > does documentation seem to be added here. Until there's some description
> > of what these are and why they're needed, I don't think they're
> > suitable.
>
> I'll add description about this patch.
Cheers.
Mark.
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