| Message ID | 20240530-max77693-charger-extcon-v1-6-dc2a9e5bdf30@gmail.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | power: supply: max77693: Toggle charging/OTG based on extcon status | expand |
On 30/05/2024 10:55, Artur Weber wrote: > There are two charger current limit registers: > > - Fast charge current limit (which controls current going from the > charger to the battery); > - CHGIN input current limit (which controls current going into the > charger through the cable, and is managed by the CHARGER regulator). > > Add functions for setting both of the values, and set them to a > safe default value of 500mA at initialization. > > The default value for the fast charge current limit can be modified > by setting the maxim,fast-charge-current-microamp DT property; the > CHGIN input current limit will be set up later in the charger detection > mechanism. > > Signed-off-by: Artur Weber <aweber.kernel@gmail.com> > --- > drivers/power/supply/max77693_charger.c | 45 +++++++++++++++++++++++++++++++++ > 1 file changed, 45 insertions(+) > > diff --git a/drivers/power/supply/max77693_charger.c b/drivers/power/supply/max77693_charger.c > index 894c35b750b3..d59b1524b0a4 100644 > --- a/drivers/power/supply/max77693_charger.c > +++ b/drivers/power/supply/max77693_charger.c > @@ -28,6 +28,7 @@ struct max77693_charger { > u32 min_system_volt; > u32 thermal_regulation_temp; > u32 batttery_overcurrent; > + u32 fast_charge_current; > u32 charge_input_threshold_volt; > }; > > @@ -591,6 +592,35 @@ static int max77693_set_batttery_overcurrent(struct max77693_charger *chg, > CHG_CNFG_12_B2SOVRC_MASK, data); > } > > +static int max77693_set_input_current_limit(struct max77693_charger *chg, > + unsigned int uamp) > +{ > + dev_dbg(chg->dev, "CHGIN input current limit: %u\n", uamp); That's quite useless debug. It duplicates max77693_set_fast_charge_current(). Just drop entire wrapper. > + > + return regulator_set_current_limit(chg->regu, (int)uamp, (int)uamp); > +} > + > +static int max77693_set_fast_charge_current(struct max77693_charger *chg, > + unsigned int uamp) > +{ > + unsigned int data; > + > + data = (uamp / 1000) * 10 / 333; /* 0.1A/3 steps */ > + > + if (data > CHG_CNFG_02_CC_MASK) { > + dev_err(chg->dev, "Wrong value for fast charge current\n"); > + return -EINVAL; > + } > + > + data <<= CHG_CNFG_02_CC_SHIFT; > + > + dev_dbg(chg->dev, "Fast charge current: %u (0x%x)\n", uamp, data); > + > + return regmap_update_bits(chg->max77693->regmap, > + MAX77693_CHG_REG_CHG_CNFG_02, > + CHG_CNFG_02_CC_MASK, data); I am surprised that you set current limit via regulator but actual charging current value here. I think both should go to regulator in such case. > Best regards, Krzysztof
On 31.05.2024 11:47, Krzysztof Kozlowski wrote: > On 30/05/2024 10:55, Artur Weber wrote: >> There are two charger current limit registers: >> >> - Fast charge current limit (which controls current going from the >> charger to the battery); >> - CHGIN input current limit (which controls current going into the >> charger through the cable, and is managed by the CHARGER regulator). >> >> Add functions for setting both of the values, and set them to a >> safe default value of 500mA at initialization. >> >> The default value for the fast charge current limit can be modified >> by setting the maxim,fast-charge-current-microamp DT property; the >> CHGIN input current limit will be set up later in the charger detection >> mechanism. >> >> Signed-off-by: Artur Weber <aweber.kernel@gmail.com> >> --- >> drivers/power/supply/max77693_charger.c | 45 +++++++++++++++++++++++++++++++++ >> 1 file changed, 45 insertions(+) >> >> diff --git a/drivers/power/supply/max77693_charger.c b/drivers/power/supply/max77693_charger.c >> index 894c35b750b3..d59b1524b0a4 100644 >> --- a/drivers/power/supply/max77693_charger.c >> +++ b/drivers/power/supply/max77693_charger.c >> @@ -28,6 +28,7 @@ struct max77693_charger { >> u32 min_system_volt; >> u32 thermal_regulation_temp; >> u32 batttery_overcurrent; >> + u32 fast_charge_current; >> u32 charge_input_threshold_volt; >> }; >> >> @@ -591,6 +592,35 @@ static int max77693_set_batttery_overcurrent(struct max77693_charger *chg, >> CHG_CNFG_12_B2SOVRC_MASK, data); >> } >> >> +static int max77693_set_input_current_limit(struct max77693_charger *chg, >> + unsigned int uamp) >> +{ >> + dev_dbg(chg->dev, "CHGIN input current limit: %u\n", uamp); > > That's quite useless debug. It duplicates > max77693_set_fast_charge_current(). Just drop entire wrapper. It doesn't duplicate max77693_set_fast_charge_current, they modify two separate registers. Quote from the commit message: > There are two charger current limit registers: > > - Fast charge current limit (which controls current going from the > charger to the battery); > - CHGIN input current limit (which controls current going into the > charger through the cable, and is managed by the CHARGER regulator). max77693_set_fast_charge_current sets up the "fast charge current" register (in CNFG_02, CHG_CNFG_02_CC). The CHARGER regulators sets the CHGIN input current (in CNFG_09, CHG_CNFG_09_CHGIN_ILIM). (Apparently the CHARGER regulator is supposed to handle the fast charge current, but it does not; I wrote about this in the "CHARGER regulator" section of the patchset description.) >> + >> + return regulator_set_current_limit(chg->regu, (int)uamp, (int)uamp); >> +} >> + >> +static int max77693_set_fast_charge_current(struct max77693_charger *chg, >> + unsigned int uamp) >> +{ >> + unsigned int data; >> + >> + data = (uamp / 1000) * 10 / 333; /* 0.1A/3 steps */ >> + >> + if (data > CHG_CNFG_02_CC_MASK) { >> + dev_err(chg->dev, "Wrong value for fast charge current\n"); >> + return -EINVAL; >> + } >> + >> + data <<= CHG_CNFG_02_CC_SHIFT; >> + >> + dev_dbg(chg->dev, "Fast charge current: %u (0x%x)\n", uamp, data); >> + >> + return regmap_update_bits(chg->max77693->regmap, >> + MAX77693_CHG_REG_CHG_CNFG_02, >> + CHG_CNFG_02_CC_MASK, data); > > I am surprised that you set current limit via regulator but actual > charging current value here. I think both should go to regulator in such > case. As in, both fast charge current and input current should be set up by the CHARGER regulator? Sure, sounds good to me. I've noticed that on the original kernel, both of the values are modified together too (only exception is that fast charge current would be set to 0 when the cable was unplugged, but the input current stayed at 500mA. This doesn't seem to affect anything, though.). At one point I actually considered going the other way around - moving all charger register handling into the charger driver, instead of having it be a regulator. As far as I can tell, only some Samsung-submitted charger drivers (max77693, max8997, max8998, max14577) use a regulator to manage the charger current (if anything, some power supply drivers expose an OTG/VBUS regulator, might be something for us to consider as well...). I see you wrote at least the max14577 and part of the max77693 driver; out of curiosity, what's the benefit of doing it through a current regulator (as opposed to adding set functions for the relevant properties in the charger driver)? I've noticed the downstream driver has a very similar pattern[1], I wonder if it's just a port of that or if there's a more concrete reason. Best regards Artur [1] https://github.com/gr8nole/android_kernel_samsung_smdk4x12/blob/lineage-14.1/drivers/regulator/max77693.c (everything related to MAX77693_CHARGER)
On 31/05/2024 13:55, Artur Weber wrote: > On 31.05.2024 11:47, Krzysztof Kozlowski wrote: >> On 30/05/2024 10:55, Artur Weber wrote: >>> There are two charger current limit registers: >>> >>> - Fast charge current limit (which controls current going from the >>> charger to the battery); >>> - CHGIN input current limit (which controls current going into the >>> charger through the cable, and is managed by the CHARGER regulator). >>> >>> Add functions for setting both of the values, and set them to a >>> safe default value of 500mA at initialization. >>> >>> The default value for the fast charge current limit can be modified >>> by setting the maxim,fast-charge-current-microamp DT property; the >>> CHGIN input current limit will be set up later in the charger detection >>> mechanism. >>> >>> Signed-off-by: Artur Weber <aweber.kernel@gmail.com> >>> --- >>> drivers/power/supply/max77693_charger.c | 45 +++++++++++++++++++++++++++++++++ >>> 1 file changed, 45 insertions(+) >>> >>> diff --git a/drivers/power/supply/max77693_charger.c b/drivers/power/supply/max77693_charger.c >>> index 894c35b750b3..d59b1524b0a4 100644 >>> --- a/drivers/power/supply/max77693_charger.c >>> +++ b/drivers/power/supply/max77693_charger.c >>> @@ -28,6 +28,7 @@ struct max77693_charger { >>> u32 min_system_volt; >>> u32 thermal_regulation_temp; >>> u32 batttery_overcurrent; >>> + u32 fast_charge_current; >>> u32 charge_input_threshold_volt; >>> }; >>> >>> @@ -591,6 +592,35 @@ static int max77693_set_batttery_overcurrent(struct max77693_charger *chg, >>> CHG_CNFG_12_B2SOVRC_MASK, data); >>> } >>> >>> +static int max77693_set_input_current_limit(struct max77693_charger *chg, >>> + unsigned int uamp) >>> +{ >>> + dev_dbg(chg->dev, "CHGIN input current limit: %u\n", uamp); >> >> That's quite useless debug. It duplicates >> max77693_set_fast_charge_current(). Just drop entire wrapper. > > It doesn't duplicate max77693_set_fast_charge_current, they modify two > separate registers. Quote from the commit message: But it is the same uamp value. Debug messages should not be per register write, because we are not debugging here registers... > >> There are two charger current limit registers: >> >> - Fast charge current limit (which controls current going from the >> charger to the battery); >> - CHGIN input current limit (which controls current going into the >> charger through the cable, and is managed by the CHARGER regulator). > > max77693_set_fast_charge_current sets up the "fast charge current" > register (in CNFG_02, CHG_CNFG_02_CC). The CHARGER regulators sets the > CHGIN input current (in CNFG_09, CHG_CNFG_09_CHGIN_ILIM). > > (Apparently the CHARGER regulator is supposed to handle the fast > charge current, but it does not; I wrote about this in the "CHARGER > regulator" section of the patchset description.) > >>> + >>> + return regulator_set_current_limit(chg->regu, (int)uamp, (int)uamp); >>> +} >>> + >>> +static int max77693_set_fast_charge_current(struct max77693_charger *chg, >>> + unsigned int uamp) >>> +{ >>> + unsigned int data; >>> + >>> + data = (uamp / 1000) * 10 / 333; /* 0.1A/3 steps */ >>> + >>> + if (data > CHG_CNFG_02_CC_MASK) { >>> + dev_err(chg->dev, "Wrong value for fast charge current\n"); >>> + return -EINVAL; >>> + } >>> + >>> + data <<= CHG_CNFG_02_CC_SHIFT; >>> + >>> + dev_dbg(chg->dev, "Fast charge current: %u (0x%x)\n", uamp, data); >>> + >>> + return regmap_update_bits(chg->max77693->regmap, >>> + MAX77693_CHG_REG_CHG_CNFG_02, >>> + CHG_CNFG_02_CC_MASK, data); >> >> I am surprised that you set current limit via regulator but actual >> charging current value here. I think both should go to regulator in such >> case. > > As in, both fast charge current and input current should be set up by > the CHARGER regulator? Sure, sounds good to me. > > I've noticed that on the original kernel, both of the values are > modified together too (only exception is that fast charge current would > be set to 0 when the cable was unplugged, but the input current stayed > at 500mA. This doesn't seem to affect anything, though.). > > At one point I actually considered going the other way around - moving > all charger register handling into the charger driver, instead of having > it be a regulator. As far as I can tell, only some Samsung-submitted > charger drivers (max77693, max8997, max8998, max14577) use a regulator > to manage the charger current (if anything, some power supply drivers > expose an OTG/VBUS regulator, might be something for us to consider as > well...). regulator choice was to match userspace design that time (long time ago), but I think now preference is to use writeable properties of power supply class. I'll defer here to Sebastian. > > I see you wrote at least the max14577 and part of the max77693 driver; > out of curiosity, what's the benefit of doing it through a current > regulator (as opposed to adding set functions for the relevant > properties in the charger driver)? I've noticed the downstream driver > has a very similar pattern[1], I wonder if it's just a port of that or > if there's a more concrete reason. > Best regards, Krzysztof
On 31.05.2024 14:18, Krzysztof Kozlowski wrote: > On 31/05/2024 13:55, Artur Weber wrote: >> On 31.05.2024 11:47, Krzysztof Kozlowski wrote: >>> On 30/05/2024 10:55, Artur Weber wrote: >>>> There are two charger current limit registers: >>>> >>>> - Fast charge current limit (which controls current going from the >>>> charger to the battery); >>>> - CHGIN input current limit (which controls current going into the >>>> charger through the cable, and is managed by the CHARGER regulator). >>>> >>>> Add functions for setting both of the values, and set them to a >>>> safe default value of 500mA at initialization. >>>> >>>> The default value for the fast charge current limit can be modified >>>> by setting the maxim,fast-charge-current-microamp DT property; the >>>> CHGIN input current limit will be set up later in the charger detection >>>> mechanism. >>>> >>>> Signed-off-by: Artur Weber <aweber.kernel@gmail.com> >>>> --- >>>> drivers/power/supply/max77693_charger.c | 45 +++++++++++++++++++++++++++++++++ >>>> 1 file changed, 45 insertions(+) >>>> >>>> diff --git a/drivers/power/supply/max77693_charger.c b/drivers/power/supply/max77693_charger.c >>>> index 894c35b750b3..d59b1524b0a4 100644 >>>> --- a/drivers/power/supply/max77693_charger.c >>>> +++ b/drivers/power/supply/max77693_charger.c >>>> @@ -28,6 +28,7 @@ struct max77693_charger { >>>> u32 min_system_volt; >>>> u32 thermal_regulation_temp; >>>> u32 batttery_overcurrent; >>>> + u32 fast_charge_current; >>>> u32 charge_input_threshold_volt; >>>> }; >>>> >>>> @@ -591,6 +592,35 @@ static int max77693_set_batttery_overcurrent(struct max77693_charger *chg, >>>> CHG_CNFG_12_B2SOVRC_MASK, data); >>>> } >>>> >>>> +static int max77693_set_input_current_limit(struct max77693_charger *chg, >>>> + unsigned int uamp) >>>> +{ >>>> + dev_dbg(chg->dev, "CHGIN input current limit: %u\n", uamp); >>> >>> That's quite useless debug. It duplicates >>> max77693_set_fast_charge_current(). Just drop entire wrapper. >> >> It doesn't duplicate max77693_set_fast_charge_current, they modify two >> separate registers. Quote from the commit message: > > But it is the same uamp value. Debug messages should not be per register > write, because we are not debugging here registers... > >> >>> There are two charger current limit registers: >>> >>> - Fast charge current limit (which controls current going from the >>> charger to the battery); >>> - CHGIN input current limit (which controls current going into the >>> charger through the cable, and is managed by the CHARGER regulator). >> >> max77693_set_fast_charge_current sets up the "fast charge current" >> register (in CNFG_02, CHG_CNFG_02_CC). The CHARGER regulators sets the >> CHGIN input current (in CNFG_09, CHG_CNFG_09_CHGIN_ILIM). >> >> (Apparently the CHARGER regulator is supposed to handle the fast >> charge current, but it does not; I wrote about this in the "CHARGER >> regulator" section of the patchset description.) >> >>>> + >>>> + return regulator_set_current_limit(chg->regu, (int)uamp, (int)uamp); >>>> +} >>>> + >>>> +static int max77693_set_fast_charge_current(struct max77693_charger *chg, >>>> + unsigned int uamp) >>>> +{ >>>> + unsigned int data; >>>> + >>>> + data = (uamp / 1000) * 10 / 333; /* 0.1A/3 steps */ >>>> + >>>> + if (data > CHG_CNFG_02_CC_MASK) { >>>> + dev_err(chg->dev, "Wrong value for fast charge current\n"); >>>> + return -EINVAL; >>>> + } >>>> + >>>> + data <<= CHG_CNFG_02_CC_SHIFT; >>>> + >>>> + dev_dbg(chg->dev, "Fast charge current: %u (0x%x)\n", uamp, data); >>>> + >>>> + return regmap_update_bits(chg->max77693->regmap, >>>> + MAX77693_CHG_REG_CHG_CNFG_02, >>>> + CHG_CNFG_02_CC_MASK, data); >>> >>> I am surprised that you set current limit via regulator but actual >>> charging current value here. I think both should go to regulator in such >>> case. >> >> As in, both fast charge current and input current should be set up by >> the CHARGER regulator? Sure, sounds good to me. Now that I look at it, there's one small problem with moving this to the CHARGER regulator - the CHGIN input limit and the fast charge current limit have different ranges for values; CHGIN input limit accepts values from 60mA to 2.58A, whereas fast charge current accepts values from 0mA to ~2.1A. (This also means the limits I described for the fast charge current property in [PATCH 2/11] are wrong...) Should we limit the CHARGER regulator to 2.1A (would require fixing every DTS that defines the limits... though maybe they should be hardcoded in the driver anyways?), or leave the limit as-is and cap the fast charge current if the CHARGER current limit is set above 2.1A, or something else entirely? Best regards Artur
diff --git a/drivers/power/supply/max77693_charger.c b/drivers/power/supply/max77693_charger.c index 894c35b750b3..d59b1524b0a4 100644 --- a/drivers/power/supply/max77693_charger.c +++ b/drivers/power/supply/max77693_charger.c @@ -28,6 +28,7 @@ struct max77693_charger { u32 min_system_volt; u32 thermal_regulation_temp; u32 batttery_overcurrent; + u32 fast_charge_current; u32 charge_input_threshold_volt; }; @@ -591,6 +592,35 @@ static int max77693_set_batttery_overcurrent(struct max77693_charger *chg, CHG_CNFG_12_B2SOVRC_MASK, data); } +static int max77693_set_input_current_limit(struct max77693_charger *chg, + unsigned int uamp) +{ + dev_dbg(chg->dev, "CHGIN input current limit: %u\n", uamp); + + return regulator_set_current_limit(chg->regu, (int)uamp, (int)uamp); +} + +static int max77693_set_fast_charge_current(struct max77693_charger *chg, + unsigned int uamp) +{ + unsigned int data; + + data = (uamp / 1000) * 10 / 333; /* 0.1A/3 steps */ + + if (data > CHG_CNFG_02_CC_MASK) { + dev_err(chg->dev, "Wrong value for fast charge current\n"); + return -EINVAL; + } + + data <<= CHG_CNFG_02_CC_SHIFT; + + dev_dbg(chg->dev, "Fast charge current: %u (0x%x)\n", uamp, data); + + return regmap_update_bits(chg->max77693->regmap, + MAX77693_CHG_REG_CHG_CNFG_02, + CHG_CNFG_02_CC_MASK, data); +} + static int max77693_set_charge_input_threshold_volt(struct max77693_charger *chg, unsigned int uvolt) { @@ -668,6 +698,15 @@ static int max77693_reg_init(struct max77693_charger *chg) if (ret) return ret; + ret = max77693_set_fast_charge_current(chg, chg->fast_charge_current); + if (ret) + return ret; + + ret = max77693_set_input_current_limit(chg, + DEFAULT_FAST_CHARGE_CURRENT); + if (ret) + return ret; + return max77693_set_charge_input_threshold_volt(chg, chg->charge_input_threshold_volt); } @@ -703,11 +742,17 @@ static int max77693_dt_init(struct device *dev, struct max77693_charger *chg) chg->charge_input_threshold_volt = DEFAULT_CHARGER_INPUT_THRESHOLD_VOLT; + if (of_property_read_u32(np, "maxim,fast-charge-current-microamp", + &chg->fast_charge_current)) + chg->fast_charge_current = DEFAULT_FAST_CHARGE_CURRENT; + return 0; } #else /* CONFIG_OF */ static int max77693_dt_init(struct device *dev, struct max77693_charger *chg) { + chg->fast_charge_current = DEFAULT_FAST_CHARGE_CURRENT; + return 0; } #endif /* CONFIG_OF */
There are two charger current limit registers: - Fast charge current limit (which controls current going from the charger to the battery); - CHGIN input current limit (which controls current going into the charger through the cable, and is managed by the CHARGER regulator). Add functions for setting both of the values, and set them to a safe default value of 500mA at initialization. The default value for the fast charge current limit can be modified by setting the maxim,fast-charge-current-microamp DT property; the CHGIN input current limit will be set up later in the charger detection mechanism. Signed-off-by: Artur Weber <aweber.kernel@gmail.com> --- drivers/power/supply/max77693_charger.c | 45 +++++++++++++++++++++++++++++++++ 1 file changed, 45 insertions(+)