Re: [PATCH V15 6/9] mfd: pm8008: Use i2c_new_dummy_device() API

[Satya Priya Kakitapalli (Temp)]

Hi Lee,


On 6/20/2022 4:37 PM, Satya Priya Kakitapalli (Temp) wrote:
> On 6/20/2022 1:50 PM, Lee Jones wrote:
> > On Mon, 20 Jun 2022, Satya Priya Kakitapalli (Temp) wrote:
> >
> > > On 6/17/2022 2:27 AM, Lee Jones wrote:
> > > > On Tue, 14 Jun 2022, Satya Priya wrote:
> > > >
> > > > > Use i2c_new_dummy_device() to register pm8008-regulator
> > > > > client present at a different address space, instead of
> > > > > defining a separate DT node. This avoids calling the probe
> > > > > twice for the same chip, once for each client pm8008-infra
> > > > > and pm8008-regulator.
> > > > >
> > > > > As a part of this define pm8008_regmap_init() to do regmap
> > > > > init for both the clients and define pm8008_get_regmap() to
> > > > > pass the regmap to the regulator driver.
> > > > >
> > > > > Signed-off-by: Satya Priya <quic_c_skakit@xxxxxxxxxxx>
> > > > > Reviewed-by: Stephen Boyd <swboyd@xxxxxxxxxxxx>
> > > > > ---
> > > > > Changes in V15:
> > > > >    - None.
> > > > >
> > > > > Changes in V14:
> > > > >    - None.
> > > > >
> > > > > Changes in V13:
> > > > >    - None.
> > > > >
> > > > >    drivers/mfd/qcom-pm8008.c       | 34 
> > > > > ++++++++++++++++++++++++++++++++--
> > > > >    include/linux/mfd/qcom_pm8008.h |  9 +++++++++
> > > > >    2 files changed, 41 insertions(+), 2 deletions(-)
> > > > >    create mode 100644 include/linux/mfd/qcom_pm8008.h
> > > > >
> > > > > diff --git a/drivers/mfd/qcom-pm8008.c b/drivers/mfd/qcom-pm8008.c
> > > > > index 569ffd50..55e2a8e 100644
> > > > > --- a/drivers/mfd/qcom-pm8008.c
> > > > > +++ b/drivers/mfd/qcom-pm8008.c
> > > > > @@ -9,6 +9,7 @@
> > > > >    #include <linux/interrupt.h>
> > > > >    #include <linux/irq.h>
> > > > >    #include <linux/irqdomain.h>
> > > > > +#include <linux/mfd/qcom_pm8008.h>
> > > > >    #include <linux/module.h>
> > > > >    #include <linux/of_device.h>
> > > > >    #include <linux/of_platform.h>
> > > > > @@ -57,6 +58,7 @@ enum {
> > > > >    struct pm8008_data {
> > > > >        struct device *dev;
> > > > > +    struct regmap *regulators_regmap;
> > > > >        int irq;
> > > > >        struct regmap_irq_chip_data *irq_data;
> > > > >    };
> > > > > @@ -150,6 +152,12 @@ static struct regmap_config 
> > > > > qcom_mfd_regmap_cfg = {
> > > > >        .max_register    = 0xFFFF,
> > > > >    };
> > > > > +struct regmap *pm8008_get_regmap(const struct pm8008_data *chip)
> > > > > +{
> > > > > +    return chip->regulators_regmap;
> > > > > +}
> > > > > +EXPORT_SYMBOL_GPL(pm8008_get_regmap);
> > > > Seems like abstraction for the sake of abstraction.
> > > >
> > > > Why not do the dereference inside the regulator driver?
> > > To derefer this in the regulator driver, we need to have the 
> > > pm8008_data
> > > struct definition in the qcom_pm8008 header file.
> > >
> > > I think it doesn't look great to have only that structure in header 
> > > and all
> > > other structs and enum in the mfd driver.
> > Then why pass 'pm8008_data' at all?
>
>
> There is one more option, instead of passing the pm8008_data, we could 
> pass the pdev->dev.parent and get the pm8008 chip data directly in the 
> pm8008_get_regmap() like below
>
>
> struct regmap *pm8008_get_regmap(const struct device *dev)
>  {
>      const struct pm8008_data *chip = dev_get_drvdata(dev);
>
>      return chip->regulators_regmap;
> }
> EXPORT_SYMBOL_GPL(pm8008_get_regmap);
>
>
> By doing this we can avoid having declaration of pm8008_data also in 
> the header. Please let me know if this looks good.

Could you please confirm on this?


> > What's preventing you from passing 'regmap'?
>
>
> I didn't get what you meant here, could you please elaborate a bit?