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From: Timur Tabi <timur@freescale.com>
To: Olof Johansson <olof@lixom.net>
Cc: linuxppc-dev@ozlabs.org, sl@powerlinux.fr,
	Philippe Lachenal <philippe.lachenal@hotmail.fr>
Subject: Re: MPC8349ea Random Device Generator driver
Date: Wed, 06 Jun 2007 17:07:05 -0500	[thread overview]
Message-ID: <46673009.6000109@freescale.com> (raw)
In-Reply-To: <20070606220913.GA27820@lixom.net>

Olof Johansson wrote:

> There's nothing wrong with the way he coded that up. Lots of drivers
> are written that way (all of mine are). It's at least as clear as any
> structure, and it doesn't cause temptation to do...

That vast majority of Freescale SOC device register maps are handled via a structure. 
He's doing everything via 32-bit operations, even though the registers are 64 bits, and 
therefore he has twice as much macros as he needs.

>>> +
>>> +
>>> +	/* check for things like FIFO underflow */
>>> +	
>>> +	u32 v;
>>> +
>>> +	v = in_be32(rng_regs + TALITOS_RNGISR_HI);
>> 	u64 v;
>> 	v = rng->rngisr;
>>
>> or something like that.  Try to use the built-in support for 64-bit data types when possible.
> 
> ...this. NO! Don't reference ioremapped memory from regular code like
> that. The way he's doing it is the preferred way.

Can you explain that better?  What is "regular code"?

-- 
Timur Tabi
Linux Kernel Developer @ Freescale

  reply	other threads:[~2007-06-06 22:07 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-06-05 15:42 MPC8349ea Random Device Generator driver Philippe Lachenal
2007-06-06 14:15 ` Arnd Bergmann
2007-06-07 11:29   ` MPC8349ea Random Number " Philippe Lachenal
2007-06-07 14:03     ` Arnd Bergmann
2007-06-06 21:57 ` MPC8349ea Random Device " Timur Tabi
2007-06-06 22:09   ` Olof Johansson
2007-06-06 22:07     ` Timur Tabi [this message]
2007-06-06 22:11       ` Arnd Bergmann
2007-06-06 22:19         ` Timur Tabi
2007-06-06 22:35           ` Arnd Bergmann
2007-06-06 22:38             ` Timur Tabi
2007-06-06 22:24       ` Olof Johansson
2007-06-06 22:32         ` Timur Tabi
2007-06-06 23:54           ` Olof Johansson
2007-06-07 14:23             ` Timur Tabi
2007-06-07 15:20               ` Olof Johansson
2007-06-07 15:20                 ` Timur Tabi
2007-06-07 15:36                   ` Olof Johansson
2007-06-06 22:48         ` Timur Tabi
2007-06-07  0:00           ` Olof Johansson
2007-06-07  2:55 ` Kim Phillips

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