linux-kernel - Re: [PATCH 2/3] iio: imu: mpu6050: add level shifter flag

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Message-ID: <CAHp75VfvmED4ZsmrH4B6m9kGsH=68-zjQd5JMszb6UBTtbF0bw@mail.gmail.com>
Date:   Mon, 25 Sep 2023 14:07:58 +0300
From:   Andy Shevchenko <andy.shevchenko@...il.com>
To:     Andreas Kemnade <andreas@...nade.info>
Cc:     jic23@...nel.org, lars@...afoo.de, robh+dt@...nel.org,
        krzysztof.kozlowski+dt@...aro.org, conor+dt@...nel.org,
        bcousson@...libre.com, tony@...mide.com,
        jean-baptiste.maneyrol@....com, chenhuiz@...s.com,
        linux-iio@...r.kernel.org, devicetree@...r.kernel.org,
        linux-kernel@...r.kernel.org, linux-omap@...r.kernel.org
Subject: Re: [PATCH 2/3] iio: imu: mpu6050: add level shifter flag

On Mon, Sep 25, 2023 at 1:26 AM Andreas Kemnade <andreas@...nade.info> wrote:
>
> Some boards fail in magnetometer probe if flag is not set.

Which flag? Can you elaborate a bit more?

Does it deserve the Fixes tag?

...

>         unsigned int val;
>         int ret;

> +       ret = regmap_update_bits(st->map, 0x1, 0x80,
> +                                st->level_shifter ? 0x80 : 0);

This is a bit cryptic, what does 1 stand for?

Also

  unsigned int mask = BIT(7);
  ...
  val = st->level_shifter ? mask : 0;

> +       if (ret)
> +               return ret;

...
> +       st->level_shifter = device_property_present(dev,
> +                                                   "invensense,level-shifter");

It was a recommendation to use _read_bool() when reading the value,
while the result will be the same.

--
With Best Regards,
Andy Shevchenko