Hi Krzysztof, On Sat, 9 Feb 2019 at 16:54, Krzysztof Kozlowski <k...@kernel.org> wrote: > > Changing voltage and enabling regulator might require delays so the > regulator stabilizes at expected level. > > Add support for "regulator-ramp-delay" binding which can introduce > required time to both enabling the regulator and to changing the > voltage.
Is this binding used in Linux? Can you please add binding documentation for this? > > Signed-off-by: Krzysztof Kozlowski <k...@kernel.org> > --- > drivers/power/regulator/regulator-uclass.c | 45 +++++++++++++++++++++- > include/power/regulator.h | 2 + > 2 files changed, 45 insertions(+), 2 deletions(-) > > diff --git a/drivers/power/regulator/regulator-uclass.c > b/drivers/power/regulator/regulator-uclass.c > index 39e46279d533..4119f244c74b 100644 > --- a/drivers/power/regulator/regulator-uclass.c > +++ b/drivers/power/regulator/regulator-uclass.c > @@ -35,10 +35,22 @@ int regulator_get_value(struct udevice *dev) > return ops->get_value(dev); > } > > +static void regulator_set_value_delay(struct udevice *dev, int old_uV, > + int new_uV, unsigned int ramp_delay) > +{ > + int delay = DIV_ROUND_UP(abs(new_uV - old_uV), ramp_delay); So the ramp delay is microseconds per (microvolt delta)? > + > + debug("regulator %s: delay %u us (%d uV -> %d uV)\n", dev->name, > + delay, old_uV, new_uV); > + > + udelay(delay); > +} > + > int regulator_set_value(struct udevice *dev, int uV) > { > const struct dm_regulator_ops *ops = dev_get_driver_ops(dev); > struct dm_regulator_uclass_platdata *uc_pdata; > + int ret, old_uV = uV; > > uc_pdata = dev_get_uclass_platdata(dev); > if (uc_pdata->min_uV != -ENODATA && uV < uc_pdata->min_uV) > @@ -49,7 +61,18 @@ int regulator_set_value(struct udevice *dev, int uV) > if (!ops || !ops->set_value) > return -ENOSYS; > > - return ops->set_value(dev, uV); > + if (uc_pdata->ramp_delay) > + old_uV = regulator_get_value(dev); > + > + ret = ops->set_value(dev, uV); > + > + if (!ret) { > + if (uc_pdata->ramp_delay && old_uV > 0) > + regulator_set_value_delay(dev, old_uV, uV, > + uc_pdata->ramp_delay); > + } > + > + return ret; > } > > /* > @@ -107,6 +130,7 @@ int regulator_set_enable(struct udevice *dev, bool enable) > { > const struct dm_regulator_ops *ops = dev_get_driver_ops(dev); > struct dm_regulator_uclass_platdata *uc_pdata; > + int ret, old_enable = 0; > > if (!ops || !ops->set_enable) > return -ENOSYS; > @@ -115,7 +139,22 @@ int regulator_set_enable(struct udevice *dev, bool > enable) > if (!enable && uc_pdata->always_on) > return 0; > > - return ops->set_enable(dev, enable); > + if (uc_pdata->ramp_delay) > + old_enable = regulator_get_enable(dev); > + > + ret = ops->set_enable(dev, enable); > + if (!ret) { > + if (uc_pdata->ramp_delay && !old_enable) { > + int uV = regulator_get_value(dev); > + > + if (uV > 0) { > + regulator_set_value_delay(dev, 0, uV, > + > uc_pdata->ramp_delay); > + } How come there is a delay when enabling it as well as when setting the voltage? > + } > + } > + > + return ret; > } > > int regulator_get_mode(struct udevice *dev) > @@ -324,6 +363,8 @@ static int regulator_pre_probe(struct udevice *dev) > -ENODATA); > uc_pdata->always_on = dev_read_bool(dev, "regulator-always-on"); > uc_pdata->boot_on = dev_read_bool(dev, "regulator-boot-on"); > + uc_pdata->ramp_delay = dev_read_u32_default(dev, > "regulator-ramp-delay", > + 0); > > /* Those values are optional (-ENODATA if unset) */ > if ((uc_pdata->min_uV != -ENODATA) && > diff --git a/include/power/regulator.h b/include/power/regulator.h > index 5318ab3acece..c13fa1f336e5 100644 > --- a/include/power/regulator.h > +++ b/include/power/regulator.h > @@ -149,6 +149,7 @@ enum regulator_flag { > * @max_uA* - maximum amperage (micro Amps) > * @always_on* - bool type, true or false > * @boot_on* - bool type, true or false > + * @ramp_delay - Time to settle down after voltage change (unit: uV/us) us/uV isn't it? > * TODO(s...@chromium.org): Consider putting the above two into @flags This comment needs updating or moving up. > * @flags: - flags value (see REGULATOR_FLAG_...) > * @name** - fdt regulator name - should be taken from the device tree > @@ -169,6 +170,7 @@ struct dm_regulator_uclass_platdata { > int max_uV; > int min_uA; > int max_uA; > + unsigned int ramp_delay; > bool always_on; > bool boot_on; > const char *name; > -- > 2.17.1 > Regards, Simon _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de https://lists.denx.de/listinfo/u-boot