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From:   Baolin Wang <baolin.wang7@gmail.com>
Date:   Thu, 10 Feb 2022 16:08:35 +0800
Message-ID: <CADBw62pmtbzr78c9J20cFbNRuTrntGg_E8TH_g=LciCVGYrYqQ@mail.gmail.com>
Subject: Re: [PATCH 3/7] iio: adc: sc27xx: structure adjuststment and optimization
To:     Cixi Geng <gengcixi@gmail.com>
Cc:     Orson Zhai <orsonzhai@gmail.com>,
        Chunyan Zhang <zhang.lyra@gmail.com>, jic23@kernel.org,
        Lars-Peter Clausen <lars@metafoo.de>,
        Rob Herring <robh+dt@kernel.org>, lgirdwood@gmail.com,
        Mark Brown <broonie@kernel.org>,
        =?UTF-8?B?5pyx546J5piOIChZdW1pbmcgWmh1LzExNDU3KQ==?= 
        <yuming.zhu1@unisoc.com>, linux-iio@vger.kernel.org,
        Devicetree List <devicetree@vger.kernel.org>,
        LKML <linux-kernel@vger.kernel.org>
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On Mon, Jan 24, 2022 at 4:07 PM Cixi Geng <gengcixi@gmail.com> wrote:
>
> Baolin Wang <baolin.wang7@gmail.com> =E4=BA=8E2022=E5=B9=B41=E6=9C=8817=
=E6=97=A5=E5=91=A8=E4=B8=80 14:15=E5=86=99=E9=81=93=EF=BC=9A
> >
> > On Thu, Jan 13, 2022 at 9:54 AM Cixi Geng <gengcixi@gmail.com> wrote:
> > >
> > > Baolin Wang <baolin.wang7@gmail.com> =E4=BA=8E2022=E5=B9=B41=E6=9C=88=
7=E6=97=A5=E5=91=A8=E4=BA=94 15:03=E5=86=99=E9=81=93=EF=BC=9A
> > > >
> > > > On Thu, Jan 6, 2022 at 9:00 PM Cixi Geng <gengcixi@gmail.com> wrote=
:
> > > > >
> > > > > From: Cixi Geng <cixi.geng1@unisoc.com>
> > > > >
> > > > > Introduce one variant device data structure to be compatible
> > > > > with SC2731 PMIC since it has different scale and ratio calculati=
on
> > > > > and so on.
> > > > >
> > > > > Signed-off-by: Yuming Zhu <yuming.zhu1@unisoc.com>
> > > > > Signed-off-by: Cixi Geng <cixi.geng1@unisoc.com>
> > > > > ---
> > > > >  drivers/iio/adc/sc27xx_adc.c | 94 ++++++++++++++++++++++++++++++=
------
> > > > >  1 file changed, 79 insertions(+), 15 deletions(-)
> > > > >
> > > > > diff --git a/drivers/iio/adc/sc27xx_adc.c b/drivers/iio/adc/sc27x=
x_adc.c
> > > > > index aee076c8e2b1..d2712e54ee79 100644
> > > > > --- a/drivers/iio/adc/sc27xx_adc.c
> > > > > +++ b/drivers/iio/adc/sc27xx_adc.c
> > > > > @@ -12,9 +12,9 @@
> > > > >  #include <linux/slab.h>
> > > > >
> > > > >  /* PMIC global registers definition */
> > > > > -#define SC27XX_MODULE_EN               0xc08
> > > > > +#define SC2731_MODULE_EN               0xc08
> > > > >  #define SC27XX_MODULE_ADC_EN           BIT(5)
> > > > > -#define SC27XX_ARM_CLK_EN              0xc10
> > > > > +#define SC2731_ARM_CLK_EN              0xc10
> > > > >  #define SC27XX_CLK_ADC_EN              BIT(5)
> > > > >  #define SC27XX_CLK_ADC_CLK_EN          BIT(6)
> > > > >
> > > > > @@ -78,6 +78,23 @@ struct sc27xx_adc_data {
> > > > >         int channel_scale[SC27XX_ADC_CHANNEL_MAX];
> > > > >         u32 base;
> > > > >         int irq;
> > > > > +       const struct sc27xx_adc_variant_data *var_data;
> > > > > +};
> > > > > +
> > > > > +/*
> > > > > + * Since different PMICs of SC27xx series can have different
> > > > > + * address and ratio, we should save ratio config and base
> > > > > + * in the device data structure.
> > > > > + */
> > > > > +struct sc27xx_adc_variant_data {
> > > > > +       u32 module_en;
> > > > > +       u32 clk_en;
> > > > > +       u32 scale_shift;
> > > > > +       u32 scale_mask;
> > > > > +       const struct sc27xx_adc_linear_graph *bscale_cal;
> > > > > +       const struct sc27xx_adc_linear_graph *sscale_cal;
> > > > > +       void (*init_scale)(struct sc27xx_adc_data *data);
> > > > > +       int (*get_ratio)(int channel, int scale);
> > > > >  };
> > > > >
> > > > >  struct sc27xx_adc_linear_graph {
> > > > > @@ -103,6 +120,16 @@ static struct sc27xx_adc_linear_graph small_=
scale_graph =3D {
> > > > >         100, 341,
> > > > >  };
> > > > >
> > > > > +static const struct sc27xx_adc_linear_graph sc2731_big_scale_gra=
ph_calib =3D {
> > > > > +       4200, 850,
> > > > > +       3600, 728,
> > > > > +};
> > > > > +
> > > > > +static const struct sc27xx_adc_linear_graph sc2731_small_scale_g=
raph_calib =3D {
> > > > > +       1000, 838,
> > > > > +       100, 84,
> > > > > +};
> > > >
> > > > The original big_scale_graph_calib and small_scale_graph_calib are =
for
> > > > SC2731 PMIC, why add new structure definition for SC2731?
> > > >
> > > > > +
> > > > >  static const struct sc27xx_adc_linear_graph big_scale_graph_cali=
b =3D {
> > > > >         4200, 856,
> > > > >         3600, 733,
> > > > > @@ -130,11 +157,11 @@ static int sc27xx_adc_scale_calibration(str=
uct sc27xx_adc_data *data,
> > > > >         size_t len;
> > > > >
> > > > >         if (big_scale) {
> > > > > -               calib_graph =3D &big_scale_graph_calib;
> > > > > +               calib_graph =3D data->var_data->bscale_cal;
> > > > >                 graph =3D &big_scale_graph;
> > > > >                 cell_name =3D "big_scale_calib";
> > > > >         } else {
> > > > > -               calib_graph =3D &small_scale_graph_calib;
> > > > > +               calib_graph =3D data->var_data->sscale_cal;
> > > > >                 graph =3D &small_scale_graph;
> > > > >                 cell_name =3D "small_scale_calib";
> > > > >         }
> > > > > @@ -160,7 +187,7 @@ static int sc27xx_adc_scale_calibration(struc=
t sc27xx_adc_data *data,
> > > > >         return 0;
> > > > >  }
> > > > >
> > > > > -static int sc27xx_adc_get_ratio(int channel, int scale)
> > > > > +static int sc2731_adc_get_ratio(int channel, int scale)
> > > > >  {
> > > > >         switch (channel) {
> > > > >         case 1:
> > > > > @@ -185,6 +212,21 @@ static int sc27xx_adc_get_ratio(int channel,=
 int scale)
> > > > >         return SC27XX_VOLT_RATIO(1, 1);
> > > > >  }
> > > > >
> > > > > +/*
> > > > > + * According to the datasheet set specific value on some channel=
.
> > > > > + */
> > > > > +static void sc2731_adc_scale_init(struct sc27xx_adc_data *data)
> > > > > +{
> > > > > +       int i;
> > > > > +
> > > > > +       for (i =3D 0; i < SC27XX_ADC_CHANNEL_MAX; i++) {
> > > > > +               if (i =3D=3D 5)
> > > > > +                       data->channel_scale[i] =3D 1;
> > > > > +               else
> > > > > +                       data->channel_scale[i] =3D 0;
> > > > > +       }
> > > > > +}
> > > >
> > > > This is unnecessary I think, please see sc27xx_adc_write_raw() that
> > > > can set the channel scale.
> > > Did you mean that all the PMIC's scale_init function should put into
> > > the sc27xx_adc_write_raw?
> >
> > No.
> >
> > > but the scale_init is all different by each PMIC, if implemented in
> > > the write_raw, will add a lot of
> > > if or switch_case branch
> >
> > What I mean is we should follow the original method to set the channel
> > scale by iio_info. Please also refer to other drivers how ot handle
> > the channel scale.
> Hi Baolin,  I understand the adc_write_raw() function is the method to se=
t
> channal scale for the userspace, we can change the channel scale by write
> a value on a user code. did i understand right?
> out  scale_init is to set scale value when the driver probe stage, and I =
also
> did not found other adc driver use the adc_write_raw() during the driver
>  initialization phase.

Hi Jonathan,

How do you think about the method in this patch to set the channel
scale? Thanks.

--=20
Baolin Wang