From: Wolfgang Grandegger <wg@grandegger•com>
To: Segher Boessenkool <segher@kernel•crashing.org>
Cc: Linuxppc-dev@ozlabs•org
Subject: Re: [PATCH] booting-without-of: add more bindings for FSL UPM driver
Date: Thu, 26 Jun 2008 15:07:29 +0200 [thread overview]
Message-ID: <48639491.90900@grandegger.com> (raw)
In-Reply-To: <a9f4227722f169bc9c2e712df774b748@kernel.crashing.org>
Hi Segher,
Segher Boessenkool wrote:
>>>> + - chip-delay : may specify a delay value in milliseconds.
>>>
>>> Delay for what? The binding should say. "chip-delay" is a bit
>>> too generic name as well, it could be more descriptive perhaps.
>>
>> The chip-delay property defines an appropriate maximum delay
>> time (tR) required for read operations if the R/B pin is not
>> connected.
>
> Yeah. So please put that in the binding.
>
>>> Shouldn't this be a property of the NAND device anyway, not the
>>> NAND controller?
>>
>> Strictly speaking, it's a property of the NAND device. Therefore it
>> should be inside the node nand@0, I thhink:
>>
>> + nand@0 {
>> + #address-cells = <1>;
>> + #size-cells = <1>;
>> + chip-delay = <25>; // in micro-seconds
>
> Something like that, yes. You wrote milliseconds before; which is it?
>
> And, a better property name, please.
>
>> Where should that be documented?
>
> In the binding for nand devices. If there isn't any yet, it might be
> best to include that with the binding for your nand controller (i.e.,
> describe the whole sub node there).
This is another try to get this binding accepted. Below is my revised
patch introducing the proper "read-fetch-delay" for the sub-nodes of
the FSL UPM nodes and documenting all other options as well.
What do you think?
Wolfgang.
From: Wolfgang Grandegger <wg@grandegger•com>
Subject: booting-without-of: add more bindings for FSL UPM driver
This patch adds the bindings for the property "read-fetch-delay" to the
sub-nodes of the "fsl,upm-nand" compatible nodes. It is used by the patch
"[NAND] driver extension to support NAND on TQM85xx modules" posted to
this list some time ago:
http://ozlabs.org/pipermail/linuxppc-dev/2008-June/057632.html
Furthermore it documents all other properties of the sub-nodes.
Note: this patch is based on the following patches from Anton
Vorontsov posted to this list some time ago:
http://ozlabs.org/pipermail/linuxppc-dev/2008-May/056531.html
http://ozlabs.org/pipermail/linuxppc-dev/2008-June/057244.html
Signed-off-by: Wolfgang Grandegger <wg@grandegger•com>
---
Documentation/powerpc/booting-without-of.txt | 34 +++++++++++++++++++++++++--
1 file changed, 32 insertions(+), 2 deletions(-)
Index: linux-2.6-galak/Documentation/powerpc/booting-without-of.txt
===================================================================
--- linux-2.6-galak.orig/Documentation/powerpc/booting-without-of.txt
+++ linux-2.6-galak/Documentation/powerpc/booting-without-of.txt
@@ -3036,6 +3036,28 @@ platforms are moved over to use the flat
- fsl,upm-cmd-offset : UPM pattern offset for the command latch.
- gpios : may specify optional GPIO connected to the Ready-Not-Busy pin.
+ Each NAND flash is represented as a sub-node of the UPM node.
+ The nodes's name represents the name of the corresponding device.
+
+ NAND flash properties:
+ - compatible : not yet used.
+ - read-fetch-delay : chip dependent delay for transfering data
+ from array to read regs (tR).
+
+ Each partition is represented as a sub-node of the NAND flash device.
+ Each node's name represents the name of the corresponding partition
+ of the flash device.
+
+ NAND flash partitions:
+ - reg : The partition's offset and size within the flash bank.
+ - label : (optional) The label / name for this flash partition. If
+ omitted, the label is taken from the node name (excluding the
+ unit address).
+ - read-only : (optional) This parameter, if present, is a hint to
+ Linux that this flash partition should only be mounted read-only.
+ This is usually used for flash partitions containing early-boot
+ firmware images or data which should not be clobbered.
+
Example:
upm@1,0 {
@@ -3049,9 +3071,17 @@ platforms are moved over to use the flat
#address-cells = <1>;
#size-cells = <1>;
compatible = "stmicro,NAND512W3A2BN6E";
+ read-fetch-delay = 25
+
+ fs@0 {
+ label = "fs";
+ reg = <0 f80000>;
+ };
- partition@0 {
- ...
+ firmware@f80000 {
+ label ="firmware";
+ reg = <f80000 80000>;
+ read-only;
};
};
};
prev parent reply other threads:[~2008-06-26 13:07 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-06-09 8:42 [PATCH] booting-without-of: add more bindings for FSL UPM driver Wolfgang Grandegger
2008-06-09 10:30 ` Segher Boessenkool
2008-06-09 15:19 ` Wolfgang Grandegger
2008-06-09 23:47 ` Segher Boessenkool
2008-06-12 8:10 ` Wolfgang Grandegger
2008-06-26 13:07 ` Wolfgang Grandegger [this message]
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