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From: Krzysztof Halasa <khc@pm.waw.pl>
To: Jean Delvare <khali@linux-fr.org>
Cc: LM Sensors <lm-sensors@lm-sensors.org>,
	LKML <linux-kernel@vger.kernel.org>
Subject: Re: I2C block reads with i2c-viapro: testers wanted
Date: Thu, 11 Aug 2005 23:39:45 +0200	[thread overview]
Message-ID: <m3iryctaou.fsf@defiant.localdomain> (raw)
In-Reply-To: <20050811215929.1df5fab0.khali@linux-fr.org> (Jean Delvare's message of "Thu, 11 Aug 2005 21:59:29 +0200")

Jean Delvare <khali@linux-fr.org> writes:

> However,
> EEPROMs are also often found on SMBus busses, those controller only
> implement a subset of all possible I2C commands.

You mean one can't drive clock and data lines at will, and the controller
(some hardware) does it instead, based on commands received from the
program (and, for example, the program interface is parallel, not 2-wire
serial). Right?

But wait, even then does the controller really know anything about
I^2C commands? How would it differentiate between, say, 8-bit and
16-bit reads? Or is it just an 8-bit EEPROM bus?

Does it do START and STOP automatically as well?

> [1] Due to an internal limitation in the Linux kernel, the maximum block
> size that can be read is actually 32 bytes, so several block reads are
> needed to retrieve larger chunks of data.

BTW: Some devices can't output all their contents in one transaction (or
with continuous byte/word read) - they are limited to one bank.
If you want to access another bank, you have to select it first.
But I think you know things like that better than me.
-- 
Krzysztof Halasa

  reply	other threads:[~2005-08-11 21:39 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2005-08-09 21:13 I2C block reads with i2c-viapro: testers wanted Jean Delvare
2005-08-10 20:31 ` Hinko Kocevar
2005-08-10 21:06   ` Jean Delvare
2005-08-10 22:23     ` [lm-sensors] " Martin Drab
2005-08-11 17:12       ` Jean Delvare
2005-08-10 23:13     ` Hinko Kocevar
2005-08-11 16:56       ` Jean Delvare
2005-08-11 19:13         ` Krzysztof Halasa
2005-08-11 19:59           ` Jean Delvare
2005-08-11 21:39             ` Krzysztof Halasa [this message]
2005-08-11 21:49               ` Jean Delvare
2005-08-11 22:08                 ` Krzysztof Halasa
2005-08-12  6:26                   ` Jean Delvare
2005-08-12 15:29                     ` Krzysztof Halasa
2005-08-12 17:58                       ` Jean Delvare
2005-08-12  1:07 ` [lm-sensors] " Mark M. Hoffman
2005-08-12  6:02   ` Jean Delvare
  -- strict thread matches above, loose matches on Subject: below --
2005-08-10  1:55 Salah Coronya
2005-08-10 10:06 ` Jean Delvare

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