From patchwork Fri Jul 17 12:39:23 2009 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Wolfram Sang X-Patchwork-Id: 29918 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from bombadil.infradead.org (bombadil.infradead.org [18.85.46.34]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by bilbo.ozlabs.org (Postfix) with ESMTPS id E5E61B7084 for ; Fri, 17 Jul 2009 22:41:49 +1000 (EST) Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.69 #1 (Red Hat Linux)) id 1MRmiq-00049H-EH; Fri, 17 Jul 2009 12:39:32 +0000 Received: from metis.ext.pengutronix.de ([2001:6f8:1178:4:290:27ff:fe1d:cc33]) by bombadil.infradead.org with esmtps (Exim 4.69 #1 (Red Hat Linux)) id 1MRmin-00049B-DL for linux-mtd@lists.infradead.org; Fri, 17 Jul 2009 12:39:30 +0000 Received: from [2001:6f8:1178:2:221:70ff:fe71:1890] (helo=pengutronix.de) by metis.ext.pengutronix.de with esmtp (Exim 4.63) (envelope-from ) id 1MRmil-0002u3-8G; Fri, 17 Jul 2009 14:39:27 +0200 From: Wolfram Sang To: linux-mtd@lists.infradead.org Subject: [PATCH] mtd/maps: add mtd-ram support to physmap_of Date: Fri, 17 Jul 2009 14:39:23 +0200 Message-Id: <1247834363-28198-1-git-send-email-w.sang@pengutronix.de> X-Mailer: git-send-email 1.6.3.1 MIME-Version: 1.0 X-SA-Exim-Connect-IP: 2001:6f8:1178:2:221:70ff:fe71:1890 X-SA-Exim-Mail-From: w.sang@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-mtd@lists.infradead.org X-Spam-Score: -0.0 (/) Cc: devicetree-discuss@ozlabs.org, Vitaly Wool , =?utf-8?q?Albrecht=20Dre=C3=9F?= , Wolfram Sang , linuxppc-dev@ozlabs.org, Ken MacLeod , David Woodhouse X-BeenThere: linux-mtd@lists.infradead.org X-Mailman-Version: 2.1.11 Precedence: list List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-mtd-bounces@lists.infradead.org Errors-To: linux-mtd-bounces+incoming=patchwork.ozlabs.org@lists.infradead.org Use physmap_of to access RAMs as mtd and add documenation for it. This approach is a lot less intrusive as adding an of-wrapper around plat-ram.c. As most extensions of plat-ram.c (e.g. custom map-functions) can't be mapped to the device tree anyhow, extending physmap_of seems to be the cleanest approach. Tested with a phyCORE-MPC5121e. Signed-off-by: Wolfram Sang Cc: Vitaly Wool Cc: Artem Bityutskiy Cc: David Woodhouse Cc: Ken MacLeod Cc: Albrecht Dreß Acked-by: Grant Likely --- Documentation/powerpc/dts-bindings/mtd-physmap.txt | 42 ++++++++++++------- drivers/mtd/maps/physmap_of.c | 4 ++ 2 files changed, 30 insertions(+), 16 deletions(-) diff --git a/Documentation/powerpc/dts-bindings/mtd-physmap.txt b/Documentation/powerpc/dts-bindings/mtd-physmap.txt index 667c9bd..80152cb 100644 --- a/Documentation/powerpc/dts-bindings/mtd-physmap.txt +++ b/Documentation/powerpc/dts-bindings/mtd-physmap.txt @@ -1,18 +1,19 @@ -CFI or JEDEC memory-mapped NOR flash +CFI or JEDEC memory-mapped NOR flash, MTD-RAM (NVRAM...) Flash chips (Memory Technology Devices) are often used for solid state file systems on embedded devices. - - compatible : should contain the specific model of flash chip(s) - used, if known, followed by either "cfi-flash" or "jedec-flash" - - reg : Address range(s) of the flash chip(s) + - compatible : should contain the specific model of mtd chip(s) + used, if known, followed by either "cfi-flash", "jedec-flash" + or "mtd-ram". + - reg : Address range(s) of the mtd chip(s) It's possible to (optionally) define multiple "reg" tuples so that - non-identical NOR chips can be described in one flash node. - - bank-width : Width (in bytes) of the flash bank. Equal to the + non-identical chips can be described in one node. + - bank-width : Width (in bytes) of the bank. Equal to the device width times the number of interleaved chips. - - device-width : (optional) Width of a single flash chip. If + - device-width : (optional) Width of a single mtd chip. If omitted, assumed to be equal to 'bank-width'. - - #address-cells, #size-cells : Must be present if the flash has + - #address-cells, #size-cells : Must be present if the device has sub-nodes representing partitions (see below). In this case both #address-cells and #size-cells must be equal to 1. @@ -22,24 +23,24 @@ are defined: - vendor-id : Contains the flash chip's vendor id (1 byte). - device-id : Contains the flash chip's device id (1 byte). -In addition to the information on the flash bank itself, the +In addition to the information on the mtd bank itself, the device tree may optionally contain additional information -describing partitions of the flash address space. This can be +describing partitions of the address space. This can be used on platforms which have strong conventions about which -portions of the flash are used for what purposes, but which don't +portions of a flash are used for what purposes, but which don't use an on-flash partition table such as RedBoot. -Each partition is represented as a sub-node of the flash device. +Each partition is represented as a sub-node of the mtd device. Each node's name represents the name of the corresponding -partition of the flash device. +partition of the mtd device. Flash partitions - - reg : The partition's offset and size within the flash bank. - - label : (optional) The label / name for this flash partition. + - reg : The partition's offset and size within the mtd bank. + - label : (optional) The label / name for this 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 + Linux that this 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. @@ -78,3 +79,12 @@ Here an example with multiple "reg" tuples: reg = <0 0x04000000>; }; }; + +An example using SRAM: + + sram@2,0 { + compatible = "samsung,k6f1616u6a", "mtd-ram"; + reg = <2 0 0x00200000>; + bank-width = <2>; + }; + diff --git a/drivers/mtd/maps/physmap_of.c b/drivers/mtd/maps/physmap_of.c index 39d357b..45eee20 100644 --- a/drivers/mtd/maps/physmap_of.c +++ b/drivers/mtd/maps/physmap_of.c @@ -360,6 +360,10 @@ static struct of_device_id of_flash_match[] = { .data = (void *)"jedec_probe", }, { + .compatible = "mtd-ram", + .data = (void *)"map_ram", + }, + { .type = "rom", .compatible = "direct-mapped" },