Re: [PATCH v3 2/5] pinctrl: st: Enhance the controller to manage unavailable registers

[Maxime Coquelin]

On 03/10/2014 10:17 AM, Lee Jones wrote:
> > From: Giuseppe Cavallaro <peppe.cavallaro@xxxxxx>
> >
> > This patch adds a new logic inside the st pinctrl to manage
> > an unsupported scenario: some sysconfig are not available!
> >
> > This is the case of STiH407 where, although documented, the
> > following registers from SYSCFG_FLASH have been removed from the SoC.
> >
> > SYSTEM_CONFIG3040
> >     Output Enable pad control for all PIO Alternate Functions
> > and
> > SYSTEM_ CONFIG3050
> >     Pull Up pad control for all PIO Alternate Functions
> >
> > Without managing this condition an imprecise external abort
> > will be detect.
> >
> > To do this the patch also reviews the st_parse_syscfgs
> > and other routines to manipulate the registers only if
> > actually available.
> > In any case, for example the st_parse_syscfgs detected
> > an error condition but no action was made in the
> > st_pctl_probe_dt.
> >
> > Signed-off-by: Maxime Coquelin <maxime.coquelin@xxxxxx>
> > Signed-off-by: Giuseppe Cavallaro <peppe.cavallaro@xxxxxx>
>
> These two SOBs need reordering.
Right,
this will be changed here and everywhere else in the series.

> > ---
> >   drivers/pinctrl/pinctrl-st.c | 106 +++++++++++++++++++++++++------------------
> >   1 file changed, 61 insertions(+), 45 deletions(-)
> >
> > diff --git a/drivers/pinctrl/pinctrl-st.c b/drivers/pinctrl/pinctrl-st.c
> > index 9fb66aa..1721611 100644
> > --- a/drivers/pinctrl/pinctrl-st.c
> > +++ b/drivers/pinctrl/pinctrl-st.c
> > @@ -410,25 +410,27 @@ static void st_pinconf_set_config(struct st_pio_control *pc,
> >   	unsigned int oe_value, pu_value, od_value;
> >   	unsigned long mask = BIT(pin);
> >
> > -	regmap_field_read(output_enable, &oe_value);
> > -	regmap_field_read(pull_up, &pu_value);
> > -	regmap_field_read(open_drain, &od_value);
> > -
> > -	/* Clear old values */
> > -	oe_value &= ~mask;
> > -	pu_value &= ~mask;
> > -	od_value &= ~mask;
> > -
> > -	if (config & ST_PINCONF_OE)
> > -		oe_value |= mask;
> > -	if (config & ST_PINCONF_PU)
> > -		pu_value |= mask;
> > -	if (config & ST_PINCONF_OD)
> > -		od_value |= mask;
> > -
> > -	regmap_field_write(output_enable, oe_value);
> > -	regmap_field_write(pull_up, pu_value);
> > -	regmap_field_write(open_drain, od_value);
> > +	if (output_enable) {
> > +		regmap_field_read(output_enable, &oe_value);
> > +		oe_value &= ~mask;
> > +		if (config & ST_PINCONF_OE)
> > +			oe_value |= mask;
> > +		regmap_field_write(output_enable, oe_value);
> > +	}
> > +	if (pull_up) {
> > +		regmap_field_read(pull_up, &pu_value);
> > +		pu_value &= ~mask;
> > +		if (config & ST_PINCONF_PU)
> > +			pu_value |= mask;
> > +		regmap_field_write(pull_up, pu_value);
> > +	}
> > +	if (open_drain) {
> > +		regmap_field_read(open_drain, &od_value);
> > +		od_value &= ~mask;
> > +		if (config & ST_PINCONF_OD)
> > +			od_value |= mask;
> > +		regmap_field_write(open_drain, od_value);
> > +	}
>
> Nice change.
>
> Nit: For consistency with the changes below, please consider placing
> new lines between the 3 outer checks.
Done

> >   }
>
> <snip>
>
> > -static void st_pinconf_get_direction(struct st_pio_control *pc,
> > -	int pin, unsigned long *config)
> > +static void st_pinconf_get_direction(struct st_pio_control *pc, int pin,
> > +				     unsigned long *config)
>
> Unrelated change?
Yes this is unrelated.
I removed this change. It will be sent later with maybe other cosmetic 
changes.

> >   {
> >   	unsigned int oe_value, pu_value, od_value;
>
> Is it worth checking for (!config) here?

That would be better indeed.
But since that lack of safety check was already present before this 
change, it should be handled in a separate patch.

I'll add this in my todo list.

> > -	regmap_field_read(pc->oe, &oe_value);
> > -	regmap_field_read(pc->pu, &pu_value);
> > -	regmap_field_read(pc->od, &od_value);
> > +	if (pc->oe) {
> > +		regmap_field_read(pc->oe, &oe_value);
> > +		if (oe_value & BIT(pin))
> > +			ST_PINCONF_PACK_OE(*config);
> > +	}
> >
> > -	if (oe_value & BIT(pin))
> > -		ST_PINCONF_PACK_OE(*config);
> > -	if (pu_value & BIT(pin))
> > -		ST_PINCONF_PACK_PU(*config);
> > -	if (od_value & BIT(pin))
> > -		ST_PINCONF_PACK_OD(*config);
> > +	if (pc->pu) {
> > +		regmap_field_read(pc->pu, &pu_value);
> > +		if (pu_value & BIT(pin))
> > +			ST_PINCONF_PACK_PU(*config);
> > +	}
> >
> > +	if (pc->od) {
> > +		regmap_field_read(pc->od, &od_value);
> > +		if (od_value & BIT(pin))
> > +			ST_PINCONF_PACK_OD(*config);
> > +	}
> >   }
>
> Nice.
>
> >   static int st_pinconf_get_retime_packed(struct st_pinctrl *info,
> > @@ -1105,8 +1116,21 @@ static int st_pctl_dt_setup_retime(struct st_pinctrl *info,
> >   	return -EINVAL;
> >   }
> >
> > -static int st_parse_syscfgs(struct st_pinctrl *info,
> > -		int bank, struct device_node *np)
> > +
> > +static struct regmap_field *st_pc_get_value(struct device *dev,
> > +					    struct regmap *regmap, int bank,
> > +					    int data, int lsb, int msb)
> > +{
> > +	struct reg_field reg = REG_FIELD((data + bank) * 4, lsb, msb);
> > +
> > +	if (data < 0)
> > +		return NULL;
>
> What happens is data < 0 and it's used in REG_FIELD?
Nothing bad, but I agree this is not crystal clear.

> Would it make more sense to make this check before calling REG_FIELD?
Yes, it will be done in the v4.

<snip>

Thanks,
Maxime
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