From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Message-ID: <48639491.90900@grandegger.com> Date: Thu, 26 Jun 2008 15:07:29 +0200 From: Wolfgang Grandegger MIME-Version: 1.0 To: Segher Boessenkool Subject: Re: [PATCH] booting-without-of: add more bindings for FSL UPM driver References: <484CECE2.9050605@grandegger.com> <519f1a6d9baeca8cfea9e8ad7a92c4d4@kernel.crashing.org> <484D49FF.4090604@grandegger.com> In-Reply-To: Content-Type: text/plain; charset=US-ASCII; format=flowed Cc: Linuxppc-dev@ozlabs.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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 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 --- 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 = ; + read-only; }; }; };