Hello All,
On Fri, 2021-01-15 at 08:26 +0000, Lee Jones wrote:
> On Fri, 08 Jan 2021, Matti Vaittinen wrote:
>
> > The helper for obtaining HW-state based DVS voltage levels
> > currently only
> > works for regulators using linear-ranges. Extend support to
> > regulators with
> > simple linear mappings and add also proper error path if pickable-
> > ranges
> > regulators call this.
> >
> > Signed-off-by: Matti Vaittinen <[email protected]>
> > ---
> > drivers/regulator/rohm-regulator.c | 23 +++++++++++++++++++++--
> > include/linux/mfd/rohm-generic.h | 6 +++++-
> > 2 files changed, 26 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/regulator/rohm-regulator.c
> > b/drivers/regulator/rohm-regulator.c
> > index 399002383b28..9248bd63afa9 100644
> > --- a/drivers/regulator/rohm-regulator.c
> > +++ b/drivers/regulator/rohm-regulator.c
> > @@ -22,13 +22,26 @@ static int set_dvs_level(const struct
> > regulator_desc *desc,
> > return ret;
> > return 0;
> > }
> > -
> > + /* If voltage is set to 0 => disable */
> > if (uv == 0) {
> > if (omask)
> > return regmap_update_bits(regmap, oreg, omask,
> > 0);
> > }
> > + /* Some setups don't allow setting own voltage but do allow
> > enabling */
> > + if (!mask) {
> > + if (omask)
> > + return regmap_update_bits(regmap, oreg, omask,
> > omask);
> > +
> > + return -EINVAL;
> > + }
> > for (i = 0; i < desc->n_voltages; i++) {
> > - ret = regulator_desc_list_voltage_linear_range(desc,
> > i);
> > + /* NOTE to next hacker - Does not support pickable
> > ranges */
> > + if (desc->linear_range_selectors)
> > + return -EINVAL;
> > + if (desc->n_linear_ranges)
> > + ret =
> > regulator_desc_list_voltage_linear_range(desc, i);
> > + else
> > + ret = regulator_desc_list_voltage_linear(desc,
> > i);
> > if (ret < 0)
> > continue;
> > if (ret == uv) {
> > @@ -79,6 +92,12 @@ int rohm_regulator_set_dvs_levels(const struct
> > rohm_dvs_config *dvs,
> > mask = dvs->lpsr_mask;
> > omask = dvs->lpsr_on_mask;
> > break;
> > + case ROHM_DVS_LEVEL_SNVS:
> > + prop = "rohm,dvs-snvs-voltage";
> > + reg = dvs->snvs_reg;
> > + mask = dvs->snvs_mask;
> > + omask = dvs->snvs_on_mask;
> > + break;
> > default:
> > return -EINVAL;
> > }
> > diff --git a/include/linux/mfd/rohm-generic.h
> > b/include/linux/mfd/rohm-generic.h
> > index e99e569d3cc1..2f5fbfd0c6b3 100644
> > --- a/include/linux/mfd/rohm-generic.h
> > +++ b/include/linux/mfd/rohm-generic.h
> > @@ -27,7 +27,8 @@ enum {
> > ROHM_DVS_LEVEL_IDLE,
> > ROHM_DVS_LEVEL_SUSPEND,
> > ROHM_DVS_LEVEL_LPSR,
> > - ROHM_DVS_LEVEL_MAX = ROHM_DVS_LEVEL_LPSR,
> > + ROHM_DVS_LEVEL_SNVS,
> > + ROHM_DVS_LEVEL_MAX = ROHM_DVS_LEVEL_SNVS,
> > };
>
> Does this actually work?
>
> The code that consumes it looks like:
>
> for (i = 0; i < ROHM_DVS_LEVEL_MAX && !ret; i++)
>
> So it will loop through like:
>
> 0 (ROHM_DVS_LEVEL_IDLE)
> 1 (ROHM_DVS_LEVEL_SUSPEND)
> 2 (ROHM_DVS_LEVEL_LPSR)
> 3 (ROHM_DVS_LEVEL_SNVS)
>
> Then break, since 'i' will be (== 4) not (< 4).
>
> So the following will never be used:
>
> 4 (ROHM_DVS_LEVEL_MAX = ROHM_DVS_LEVEL_SNVS)
>
> Unless I'm missing something, I think MAX should be the last entry.
I did some further digging. The first enum member is
ROHM_DVS_LEVEL_UNKNOWN => first valid value is 1 (ROHM_DVS_LEVEL_RUN).
=> logic for this part was correct.
But I think there is a problem in how these enum values are used!
for example at bd718x7_regulator.c
.level_map = ROHM_DVS_LEVEL_RUN | ROHM_DVS_LEVEL_IDLE |
ROHM_DVS_LEVEL_SUSPEND
This works for values 1 & 2 - but fails miserably for 3...
I see these levels are also used by various boards - so I wonder how
they have worked - and I wonder if fixing this will cause problems...
I will any way send a patch (separately from this series as I guess
this should be fixed rather sooner than later) to fix this.
>
> > /**
> > @@ -66,6 +67,9 @@ struct rohm_dvs_config {
> > unsigned int lpsr_reg;
> > unsigned int lpsr_mask;
> > unsigned int lpsr_on_mask;
> > + unsigned int snvs_reg;
> > + unsigned int snvs_mask;
> > + unsigned int snvs_on_mask;
> > };
> >
> > #if IS_ENABLED(CONFIG_REGULATOR_ROHM)
