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References: <20220510141753.3878390-1-Qing-wu.Li@leica-geosystems.com.cn> <20220510141753.3878390-2-Qing-wu.Li@leica-geosystems.com.cn>
In-Reply-To: <20220510141753.3878390-2-Qing-wu.Li@leica-geosystems.com.cn>
From:   Alexandru Ardelean <ardeleanalex@gmail.com>
Date:   Thu, 12 May 2022 10:14:47 +0300
Message-ID: <CA+U=DsqUztHxrkYsWTNz8Xm1OxRK2Wkb7L7Csque4r1tEDz_ig@mail.gmail.com>
Subject: Re: [PATCH V2 1/6] iio: accel: bmi088: Modified the scale calculate
To:     LI Qingwu <Qing-wu.Li@leica-geosystems.com.cn>
Cc:     Jonathan Cameron <jic23@kernel.org>,
        Lars-Peter Clausen <lars@metafoo.de>,
        mchehab+huawei@kernel.org, linux-iio <linux-iio@vger.kernel.org>,
        LKML <linux-kernel@vger.kernel.org>,
        Rob Herring <robh+dt@kernel.org>,
        Mike Looijmans <mike.looijmans@topic.nl>,
        devicetree <devicetree@vger.kernel.org>
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Precedence: bulk

On Tue, May 10, 2022 at 5:17 PM LI Qingwu
<Qing-wu.Li@leica-geosystems.com.cn> wrote:
>
> The units after application of scale are 100*m/s^2,
> The scale calculation is only for the device
> with the range of 3, 6, 12, and 24g,
> but some other chips have a range of 2, 4, 6, and 8g.
>
> Modified the formula to a scale list.
> The scales in the list are calculated by 1/sensitivity*9.8.
> The new units after the application of scale are m/s^2.
>

Strictly on the code:

Reviewed-by: Alexandru Ardelean <ardeleanalex@gmail.com>

On the change of IIO_VAL_FRACTIONAL_LOG2 -> IIO_VAL_INT_PLUS_MICRO  is
still up for discussion.

> Signed-off-by: LI Qingwu <Qing-wu.Li@leica-geosystems.com.cn>
> ---
>  drivers/iio/accel/bmi088-accel-core.c | 12 +++++++-----
>  1 file changed, 7 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/iio/accel/bmi088-accel-core.c b/drivers/iio/accel/bmi088-accel-core.c
> index a06dae5c971d..9300313b63cb 100644
> --- a/drivers/iio/accel/bmi088-accel-core.c
> +++ b/drivers/iio/accel/bmi088-accel-core.c
> @@ -119,6 +119,7 @@ struct bmi088_accel_chip_info {
>         u8 chip_id;
>         const struct iio_chan_spec *channels;
>         int num_channels;
> +       const int scale_table[4][2];
>  };
>
>  struct bmi088_accel_data {
> @@ -280,6 +281,7 @@ static int bmi088_accel_read_raw(struct iio_dev *indio_dev,
>         struct bmi088_accel_data *data = iio_priv(indio_dev);
>         struct device *dev = regmap_get_device(data->regmap);
>         int ret;
> +       int reg;
>
>         switch (mask) {
>         case IIO_CHAN_INFO_RAW:
> @@ -330,13 +332,12 @@ static int bmi088_accel_read_raw(struct iio_dev *indio_dev,
>                                 return ret;
>
>                         ret = regmap_read(data->regmap,
> -                                         BMI088_ACCEL_REG_ACC_RANGE, val);
> +                                         BMI088_ACCEL_REG_ACC_RANGE, &reg);
>                         if (ret)
>                                 goto out_read_raw_pm_put;
> -
> -                       *val2 = 15 - (*val & 0x3);
> -                       *val = 3 * 980;
> -                       ret = IIO_VAL_FRACTIONAL_LOG2;
> +                       *val = data->chip_info->scale_table[reg&0x03][0];
> +                       *val2 = data->chip_info->scale_table[reg&0x03][1];
> +                       ret = IIO_VAL_INT_PLUS_MICRO;
>
>                         goto out_read_raw_pm_put;
>                 default:
> @@ -432,6 +433,7 @@ static const struct bmi088_accel_chip_info bmi088_accel_chip_info_tbl[] = {
>                 .chip_id = 0x1E,
>                 .channels = bmi088_accel_channels,
>                 .num_channels = ARRAY_SIZE(bmi088_accel_channels),
> +               .scale_table = {{0, 897}, {0, 1795}, {0, 3590}, {0, 7179}},
>         },
>  };
>
> --
> 2.25.1
>