From: Evgeniy Polyakov <zbr@ioremap.net>
To: Greg KH <greg@kroah.com>, Akira Shimahara <akira215corp@gmail.com>
Cc: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v3 2/5] w1_therm: adding sysfs entry to check device power
Date: Wed, 29 Apr 2020 18:18:14 +0300 [thread overview]
Message-ID: <330221588173223@mail.yandex.ru> (raw)
In-Reply-To: <20200429134655.GB2132814@kroah.com>
Hi
29.04.2020, 16:47, "Greg KH" <greg@kroah.com>:
>> +What: /sys/bus/w1/devices/.../w1_slave
>> +Date: Apr 2020
>> +Contact: Akira Shimahara <akira215corp@gmail.com>
>> +Description:
>> + (RW) return the temperature in 1/1000 degC.
>> + *read*: return 2 lines with the hexa output data sent on the
>> + bus, return the CRC check and temperature in 1/1000 degC
>
> the w1_slave file returns a temperature???
>
> And sysfs is 1 value-per-file, not multiple lines.
It was 'content crc' previously, and probably a good idea would be to add just one file with 'content'
> And as this is a temperature, what's wrong with the iio interface that
> handles temperature already? Don't go making up new userspace apis when
> we already have good ones today :)
What is that?
w1 always had a sysfs files for its contents whether it is converted temperature or raw bytes data,
there is also netlink interface which is there since the day one.
>> + *write* :
>> + * `0` : save the 2 or 3 bytes to the device EEPROM
>> + (i.e. TH, TL and config register)
>> + * `9..12` : set the device resolution in RAM
>> + (if supported)
>
> I don't understand these write values, how do they match up to a
> temperature readin?
You kind of writing to device about how to convert its raw content into readable content, which will eventually become a temperature
next prev parent reply other threads:[~2020-04-29 15:21 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-29 13:32 [PATCH v3 2/5] w1_therm: adding sysfs entry to check device power Akira Shimahara
2020-04-29 13:46 ` Greg KH
2020-04-29 13:57 ` _ Akira shimahara
2020-04-29 15:18 ` Evgeniy Polyakov [this message]
2020-04-30 10:34 ` [PATCH v3 2/5] w1_therm: adding sysfs entry to check device power Akira shimahara
2020-04-30 11:21 ` Greg KH
2020-04-30 13:52 ` Akira shimahara
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