Re: [PATCH] mfd: axp20x: Change volatile ranges on axp803

[Icenowy Zheng]

在 2026-03-21六的 07:25 +0100，Jernej Škrabec写道：
> Dne nedelja, 15. marec 2026 ob 13:49:31 Srednjeevropski standardni
> čas je Ondřej Jirman napisal(a):
> > From: Ondrej Jirman <megi@xxxxxx>
> > 
> > Regulator control registers can be cached. They don't update by
> > themselves. Enable cache on them, to speed up voltage changes,
> > particularly DCDC2 which needs to be handled quickly due to being
> > used
> > for CPUX cores and is changed very frequently by some cpufreq
> > schedulers.
> 
> That's not really the case, DCDC2-DCDC6 registers have DVM finished
> status
> bit, which is volatile and it is right to have them in volatile
> range.
> However, it is true that other registers are non-volatile, so that
> range can
> be considerably shrinked. It seems that AXP288 have same register
> layout
> but I can't say for sure (I only found datasheet for AXP288C), so
> it's best
> to leave it alone and apply changes only to AXP803. 

I have AXP288 datasheet, and register map looks the same with AXP288C.

BTW I think AXP288/288C/803/813(PMIC part) is the same die -- they have
the same "IC type no" value of 0b010001, and their difference could be
explained as package difference -- AXP803 doesn't wire AXP813's DCDC7
and wire SWIN to DCDC1 out, and AXP288 doesn't wire AXP813's DCDC3. (As
of RSB, all AXP PMICs boot at I2C mode by default, and the main SoC
switches it to RSB when it's needed; AXP288 is paired with non-
Allwinner SoCs (Intel ones) so it just doesn't advertise RSB.)

Thanks,
Icenowy

> 
> Best regards,
> Jernej
> 
> > 
> > This shrinks register access over RSB bus to one write per voltage
> > change (down from 4 or so).
> > 
> > Signed-off-by: Ondrej Jirman <megi@xxxxxx>
> > ---
> >  drivers/mfd/axp20x.c | 28 +++++++++++++++++++++++++++-
> >  1 file changed, 27 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/mfd/axp20x.c b/drivers/mfd/axp20x.c
> > index 0d0d40972eb8..2ea409029d2f 100644
> > --- a/drivers/mfd/axp20x.c
> > +++ b/drivers/mfd/axp20x.c
> > @@ -172,6 +172,18 @@ static const struct regmap_range
> > axp288_volatile_ranges[] = {
> >  	regmap_reg_range(AXP20X_FG_RES, AXP288_FG_CC_CAP_REG),
> >  };
> >  
> > +static const struct regmap_range axp803_volatile_ranges[] = {
> > +	regmap_reg_range(AXP20X_PWR_INPUT_STATUS,
> > AXP288_POWER_REASON),
> > +	regmap_reg_range(AXP288_BC_GLOBAL, AXP288_BC_GLOBAL),
> > +	regmap_reg_range(AXP288_BC_DET_STAT,
> > AXP20X_VBUS_IPSOUT_MGMT),
> > +	regmap_reg_range(AXP20X_CHRG_BAK_CTRL,
> > AXP20X_CHRG_BAK_CTRL),
> > +	regmap_reg_range(AXP20X_IRQ1_EN, AXP20X_IPSOUT_V_HIGH_L),
> > +	regmap_reg_range(AXP20X_TIMER_CTRL, AXP20X_TIMER_CTRL),
> > +	regmap_reg_range(AXP20X_GPIO1_CTRL, AXP22X_GPIO_STATE),
> > +	regmap_reg_range(AXP288_RT_BATT_V_H, AXP288_RT_BATT_V_L),
> > +	regmap_reg_range(AXP20X_FG_RES, AXP288_FG_CC_CAP_REG),
> > +};
> > +
> >  static const struct regmap_access_table axp288_writeable_table = {
> >  	.yes_ranges	= axp288_writeable_ranges,
> >  	.n_yes_ranges	= ARRAY_SIZE(axp288_writeable_ranges),
> > @@ -182,6 +194,11 @@ static const struct regmap_access_table
> > axp288_volatile_table = {
> >  	.n_yes_ranges	= ARRAY_SIZE(axp288_volatile_ranges),
> >  };
> >  
> > +static const struct regmap_access_table axp803_volatile_table = {
> > +	.yes_ranges	= axp803_volatile_ranges,
> > +	.n_yes_ranges	= ARRAY_SIZE(axp803_volatile_ranges),
> > +};
> > +
> >  static const struct regmap_range axp806_writeable_ranges[] = {
> >  	regmap_reg_range(AXP20X_DATACACHE(0),
> > AXP20X_DATACACHE(3)),
> >  	regmap_reg_range(AXP806_PWR_OUT_CTRL1,
> > AXP806_CLDO3_V_CTRL),
> > @@ -456,6 +473,15 @@ static const struct regmap_config
> > axp22x_regmap_config = {
> >  	.cache_type	= REGCACHE_MAPLE,
> >  };
> >  
> > +static const struct regmap_config axp803_regmap_config = {
> > +	.reg_bits	= 8,
> > +	.val_bits	= 8,
> > +	.wr_table	= &axp288_writeable_table,
> > +	.volatile_table	= &axp803_volatile_table,
> > +	.max_register	= AXP288_FG_TUNE5,
> > +	.cache_type	= REGCACHE_MAPLE,
> > +};
> > +
> >  static const struct regmap_config axp288_regmap_config = {
> >  	.reg_bits	= 8,
> >  	.val_bits	= 8,
> > @@ -1368,7 +1394,7 @@ int axp20x_match_device(struct axp20x_dev
> > *axp20x)
> >  	case AXP803_ID:
> >  		axp20x->nr_cells = ARRAY_SIZE(axp803_cells);
> >  		axp20x->cells = axp803_cells;
> > -		axp20x->regmap_cfg = &axp288_regmap_config;
> > +		axp20x->regmap_cfg = &axp803_regmap_config;
> >  		axp20x->regmap_irq_chip = &axp803_regmap_irq_chip;
> >  		break;
> >  	case AXP806_ID:
> > 
> 
> 
> 
>