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 [EMAIL PROTECTED], I thhink:
+ [EMAIL PROTECTED] {
+ #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 <[EMAIL PROTECTED]>
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 <[EMAIL PROTECTED]>
---
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:
[EMAIL PROTECTED],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
+
+ [EMAIL PROTECTED] {
+ label = "fs";
+ reg = <0 f80000>;
+ };
- [EMAIL PROTECTED] {
- ...
+ [EMAIL PROTECTED] {
+ label ="firmware";
+ reg = <f80000 80000>;
+ read-only;
};
};
};
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