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Subject: Re: [PATCH resend v1 1/3] units: Add SI metric prefix definitions
To:     Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
        linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org
Cc:     Mika Westerberg <mika.westerberg@linux.intel.com>, wsa@kernel.org
References: <20210603160433.35816-1-andriy.shevchenko@linux.intel.com>
From:   Jarkko Nikula <jarkko.nikula@linux.intel.com>
Message-ID: <0466dab7-f2d2-3b7c-52a6-a12a6b09a67f@linux.intel.com>
Date:   Mon, 7 Jun 2021 15:33:31 +0300
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On 6/3/21 7:04 PM, Andy Shevchenko wrote:
> Sometimes it's useful to have well-defined SI metric prefix to be used
> to self-describe the formulas or equations.
> 
> List most popular ones in the units.h.
> 
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> ---
>   include/linux/units.h | 16 ++++++++++++++++
>   1 file changed, 16 insertions(+)
> 
> diff --git a/include/linux/units.h b/include/linux/units.h
> index dcc30a53fa93..7366fcd45ec2 100644
> --- a/include/linux/units.h
> +++ b/include/linux/units.h
> @@ -4,6 +4,22 @@
>   
>   #include <linux/math.h>
>   
> +/* Metric prefixes in accordance with Système international (d'unités) */
> +#define PETA	1000000000000000LL
> +#define TERA	1000000000000LL
> +#define GIGA	1000000000L
> +#define MEGA	1000000L
> +#define KILO	1000L
> +#define HECTO	100L
> +#define DECA	10L
> +#define DECI	10L
> +#define CENTI	100L
> +#define MILLI	1000L
> +#define MICRO	1000000L
> +#define NANO	1000000000L
> +#define PICO	1000000000000LL
> +#define FEMTO	1000000000000000LL
> +

For me milli is always 1/1000. Might lead to confusion with these 
defines if idea is to multiply with KILO but divide with MILLI?

Jarkko