From: Wolfgang Grandegger <wg@grandegger•com>
To: Sergei Shtylyov <sshtylyov@ru•mvista.com>
Cc: linuxppc-embedded@ozlabs•org
Subject: Re: Flat device tree definitions for FLASH and MTD partitioning
Date: Wed, 25 Apr 2007 20:57:13 +0200 [thread overview]
Message-ID: <462FA489.1050508@grandegger.com> (raw)
In-Reply-To: <462F6707.80502@ru.mvista.com>
Sergei Shtylyov wrote:
> Hello.
>
> Wolfgang Grandegger wrote:
>
>>>>>>> are there already some thought or even example code on how to
>>>>>>> define Flash memory and MTD partitions in the DTS. This would
>>>>>>> avoid the ackward MTD partitioning via static structure or boot
>>>>>>> line argument and could be done in a generic way.
>
>>>>>> See Documentation/powerpc/booting-without-of.txt and
>>>>>> drivers/mtd/physmap_of.c for what's been already done.
>
>>>>> I meant drivers/mtd/maps/physmap_of.c
>
>>>> I had a closer look to this driver. Unfortunately, it can not handle
>>>> yet multiple FLASH banks. This could be achieved with an additional
>>>> property "bank_count". What do you think?
>
> Please use hyphen, not underscore in property names ("device_type"
> seems an only exception from this rule).
>
>>> I'm not sure what banks you're talking about -- note that this
>>> driver is equivalen in functionality to the plain 'physmap' driver
>>> and there's inherited "bank-width" property that handles flash banking.
>
>> Yes, I know. Nevertheless the driver cannot handle flash regions
>> composed of more than on FLASH bank because we need to probe every
>> bank. Search for "BANK" in drivers/mtd/maps" to understand what I mean.
>
> Hm, from what I could see, those banks are separate maps registered to
> MTD subsys separately.
> What's the point of adding a count property when we simply can define
> multiple "rom" devices?
Well, I was wrong. In the meantime I realized that physmap can handle
flash region compiosed of multiple banks. Sorry for the noise.
Wolfgang.
next prev parent reply other threads:[~2007-04-25 18:53 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-04-08 11:37 Flat device tree definitions for FLASH and MTD partitioning Wolfgang Grandegger
2007-04-08 12:11 ` Sergei Shtylyov
2007-04-08 12:21 ` Sergei Shtylyov
2007-04-08 12:41 ` Wolfgang Grandegger
2007-04-25 12:55 ` Wolfgang Grandegger
2007-04-25 13:35 ` Sergei Shtylyov
2007-04-25 14:02 ` Wolfgang Grandegger
2007-04-25 14:34 ` Sergei Shtylyov
2007-04-25 18:57 ` Wolfgang Grandegger [this message]
2007-04-26 8:21 ` Wolfgang Grandegger
2007-04-26 12:36 ` Sergei Shtylyov
2007-04-26 12:59 ` Wolfgang Grandegger
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