[POWERPC] Document and implement an improved flash device binding for powerpc
This replaces the binding for flash chips in booting-without-of.txt with an clarified and improved version. It also makes drivers/mtd/maps/physmap_of.c recognize this new binding. Finally it revises the Ebony device tree source to use the new binding as an example. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Acked-by: Segher Boessenkool <segher@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
This commit is contained in:
David Gibson
Paul Mackerras
parent
3c607ce2a3
commit
2099172d61
3 changed files with 248 additions and 107 deletions
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@ -50,7 +50,7 @@ Table of Contents
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g) Freescale SOC SEC Security Engines
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h) Board Control and Status (BCSR)
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i) Freescale QUICC Engine module (QE)
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j) Flash chip nodes
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j) CFI or JEDEC memory-mapped NOR flash
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k) Global Utilities Block
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VII - Specifying interrupt information for devices
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@ -1757,45 +1757,69 @@ platforms are moved over to use the flattened-device-tree model.
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};
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};
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j) Flash chip nodes
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j) CFI or JEDEC memory-mapped NOR flash
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Flash chips (Memory Technology Devices) are often used for solid state
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file systems on embedded devices.
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Required properties:
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- compatible : should contain the specific model of flash chip(s)
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used, if known, followed by either "cfi-flash" or "jedec-flash"
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- reg : Address range of the flash chip
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- bank-width : Width (in bytes) of the flash bank. Equal to the
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device width times the number of interleaved chips.
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- device-width : (optional) Width of a single flash chip. If
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omitted, assumed to be equal to 'bank-width'.
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- #address-cells, #size-cells : Must be present if the flash has
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sub-nodes representing partitions (see below). In this case
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both #address-cells and #size-cells must be equal to 1.
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- device_type : has to be "rom"
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- compatible : Should specify what this flash device is compatible with.
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Currently, this is most likely to be "direct-mapped" (which
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corresponds to the MTD physmap mapping driver).
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- reg : Offset and length of the register set (or memory mapping) for
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the device.
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- bank-width : Width of the flash data bus in bytes. Required
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for the NOR flashes (compatible == "direct-mapped" and others) ONLY.
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For JEDEC compatible devices, the following additional properties
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are defined:
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Recommended properties :
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- vendor-id : Contains the flash chip's vendor id (1 byte).
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- device-id : Contains the flash chip's device id (1 byte).
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- partitions : Several pairs of 32-bit values where the first value is
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partition's offset from the start of the device and the second one is
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partition size in bytes with LSB used to signify a read only
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partition (so, the partition size should always be an even number).
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- partition-names : The list of concatenated zero terminated strings
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representing the partition names.
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- probe-type : The type of probe which should be done for the chip
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(JEDEC vs CFI actually). Valid ONLY for NOR flashes.
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In addition to the information on the flash bank itself, the
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device tree may optionally contain additional information
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describing partitions of the flash address space. This can be
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used on platforms which have strong conventions about which
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portions of the flash are used for what purposes, but which don't
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use an on-flash partition table such as RedBoot.
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Example:
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Each partition is represented as a sub-node of the flash device.
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Each node's name represents the name of the corresponding
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partition of the flash device.
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flash@ff000000 {
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device_type = "rom";
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compatible = "direct-mapped";
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probe-type = "CFI";
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reg = <ff000000 01000000>;
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bank-width = <4>;
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partitions = <00000000 00f80000
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00f80000 00080001>;
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partition-names = "fs\0firmware";
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};
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Flash partitions
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- reg : The partition's offset and size within the flash bank.
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- label : (optional) The label / name for this flash partition.
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If omitted, the label is taken from the node name (excluding
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the unit address).
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- read-only : (optional) This parameter, if present, is a hint to
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Linux that this flash partition should only be mounted
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read-only. This is usually used for flash partitions
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containing early-boot firmware images or data which should not
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be clobbered.
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Example:
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flash@ff000000 {
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compatible = "amd,am29lv128ml", "cfi-flash";
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reg = <ff000000 01000000>;
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bank-width = <4>;
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device-width = <1>;
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#address-cells = <1>;
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#size-cells = <1>;
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fs@0 {
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label = "fs";
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reg = <0 f80000>;
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};
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firmware@f80000 {
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label ="firmware";
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reg = <f80000 80000>;
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read-only;
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};
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};
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k) Global Utilities Block
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@ -138,13 +138,16 @@
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interrupt-parent = <&UIC1>;
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small-flash@0,80000 {
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device_type = "rom";
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compatible = "direct-mapped";
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probe-type = "JEDEC";
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compatible = "jedec-flash";
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bank-width = <1>;
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partitions = <0 80000>;
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partition-names = "OpenBIOS";
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reg = <0 80000 80000>;
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#address-cells = <1>;
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#size-cells = <1>;
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partition@0 {
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label = "OpenBIOS";
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reg = <0 80000>;
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read-only;
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};
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};
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ds1743@1,0 {
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@ -154,14 +157,19 @@
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};
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large-flash@2,0 {
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device_type = "rom";
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compatible = "direct-mapped";
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probe-type = "JEDEC";
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compatible = "jedec-flash";
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bank-width = <1>;
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partitions = <0 380000
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380000 80000>;
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partition-names = "fs", "firmware";
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reg = <2 0 400000>;
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#address-cells = <1>;
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#size-cells = <1>;
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partition@0 {
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label = "fs";
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reg = <0 380000>;
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};
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partition@380000 {
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label = "firmware";
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reg = <380000 80000>;
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};
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};
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ir@3,0 {
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@ -4,6 +4,9 @@
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* Copyright (C) 2006 MontaVista Software Inc.
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* Author: Vitaly Wool <vwool@ru.mvista.com>
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*
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* Revised to handle newer style flash binding by:
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* Copyright (C) 2007 David Gibson, IBM Corporation.
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by the
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* Free Software Foundation; either version 2 of the License, or (at your
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@ -30,56 +33,135 @@ struct physmap_flash_info {
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struct map_info map;
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struct resource *res;
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#ifdef CONFIG_MTD_PARTITIONS
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int nr_parts;
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struct mtd_partition *parts;
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#endif
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};
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static const char *rom_probe_types[] = { "cfi_probe", "jedec_probe", "map_rom", NULL };
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#ifdef CONFIG_MTD_PARTITIONS
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static const char *part_probe_types[] = { "cmdlinepart", "RedBoot", NULL };
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#endif
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#ifdef CONFIG_MTD_PARTITIONS
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static int parse_flash_partitions(struct device_node *node,
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struct mtd_partition **parts)
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static int parse_obsolete_partitions(struct of_device *dev,
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struct physmap_flash_info *info,
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struct device_node *dp)
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{
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int i, plen, retval = -ENOMEM;
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const u32 *part;
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const char *name;
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int i, plen, nr_parts;
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const struct {
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u32 offset, len;
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} *part;
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const char *names;
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part = of_get_property(node, "partitions", &plen);
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if (part == NULL)
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goto err;
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part = of_get_property(dp, "partitions", &plen);
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if (!part)
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return -ENOENT;
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retval = plen / (2 * sizeof(u32));
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*parts = kzalloc(retval * sizeof(struct mtd_partition), GFP_KERNEL);
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if (*parts == NULL) {
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dev_warn(&dev->dev, "Device tree uses obsolete partition map binding\n");
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nr_parts = plen / sizeof(part[0]);
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info->parts = kzalloc(nr_parts * sizeof(struct mtd_partition), GFP_KERNEL);
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if (!info->parts) {
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printk(KERN_ERR "Can't allocate the flash partition data!\n");
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goto err;
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return -ENOMEM;
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}
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name = of_get_property(node, "partition-names", &plen);
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names = of_get_property(dp, "partition-names", &plen);
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for (i = 0; i < retval; i++) {
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(*parts)[i].offset = *part++;
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(*parts)[i].size = *part & ~1;
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if (*part++ & 1) /* bit 0 set signifies read only partition */
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(*parts)[i].mask_flags = MTD_WRITEABLE;
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for (i = 0; i < nr_parts; i++) {
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info->parts[i].offset = part->offset;
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info->parts[i].size = part->len & ~1;
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if (part->len & 1) /* bit 0 set signifies read only partition */
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info->parts[i].mask_flags = MTD_WRITEABLE;
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if (name != NULL && plen > 0) {
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int len = strlen(name) + 1;
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if (names && (plen > 0)) {
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int len = strlen(names) + 1;
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(*parts)[i].name = (char *)name;
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info->parts[i].name = (char *)names;
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plen -= len;
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name += len;
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} else
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(*parts)[i].name = "unnamed";
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names += len;
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} else {
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info->parts[i].name = "unnamed";
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}
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part++;
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}
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err:
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return retval;
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return nr_parts;
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}
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#endif
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static int __devinit process_partitions(struct physmap_flash_info *info,
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struct of_device *dev)
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{
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const char *partname;
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static const char *part_probe_types[]
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= { "cmdlinepart", "RedBoot", NULL };
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struct device_node *dp = dev->node, *pp;
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int nr_parts, i;
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/* First look for RedBoot table or partitions on the command
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* line, these take precedence over device tree information */
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nr_parts = parse_mtd_partitions(info->mtd, part_probe_types,
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&info->parts, 0);
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if (nr_parts > 0) {
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add_mtd_partitions(info->mtd, info->parts, nr_parts);
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return 0;
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}
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/* First count the subnodes */
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nr_parts = 0;
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for (pp = dp->child; pp; pp = pp->sibling)
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nr_parts++;
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if (nr_parts) {
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info->parts = kzalloc(nr_parts * sizeof(struct mtd_partition),
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GFP_KERNEL);
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if (!info->parts) {
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printk(KERN_ERR "Can't allocate the flash partition data!\n");
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return -ENOMEM;
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}
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for (pp = dp->child, i = 0 ; pp; pp = pp->sibling, i++) {
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const u32 *reg;
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int len;
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reg = of_get_property(pp, "reg", &len);
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if (!reg || (len != 2*sizeof(u32))) {
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dev_err(&dev->dev, "Invalid 'reg' on %s\n",
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dp->full_name);
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kfree(info->parts);
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info->parts = NULL;
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return -EINVAL;
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}
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info->parts[i].offset = reg[0];
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info->parts[i].size = reg[1];
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partname = of_get_property(pp, "label", &len);
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if (!partname)
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partname = of_get_property(pp, "name", &len);
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info->parts[i].name = (char *)partname;
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if (of_get_property(pp, "read-only", &len))
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info->parts[i].mask_flags = MTD_WRITEABLE;
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}
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} else {
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nr_parts = parse_obsolete_partitions(dev, info, dp);
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}
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if (nr_parts < 0)
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return nr_parts;
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if (nr_parts > 0)
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add_mtd_partitions(info->mtd, info->parts, nr_parts);
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else
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add_mtd_device(info->mtd);
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return 0;
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}
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#else /* MTD_PARTITIONS */
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static int __devinit process_partitions(struct physmap_flash_info *info,
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struct device_node *dev)
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{
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add_mtd_device(info->mtd);
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return 0;
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}
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#endif /* MTD_PARTITIONS */
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static int of_physmap_remove(struct of_device *dev)
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{
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@ -92,7 +174,7 @@ static int of_physmap_remove(struct of_device *dev)
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if (info->mtd != NULL) {
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#ifdef CONFIG_MTD_PARTITIONS
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if (info->nr_parts) {
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if (info->parts) {
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del_mtd_partitions(info->mtd);
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kfree(info->parts);
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} else {
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@ -115,17 +197,51 @@ static int of_physmap_remove(struct of_device *dev)
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return 0;
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}
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/* Helper function to handle probing of the obsolete "direct-mapped"
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* compatible binding, which has an extra "probe-type" property
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* describing the type of flash probe necessary. */
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static struct mtd_info * __devinit obsolete_probe(struct of_device *dev,
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struct map_info *map)
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{
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struct device_node *dp = dev->node;
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const char *of_probe;
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struct mtd_info *mtd;
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static const char *rom_probe_types[]
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= { "cfi_probe", "jedec_probe", "map_rom"};
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int i;
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dev_warn(&dev->dev, "Device tree uses obsolete \"direct-mapped\" "
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"flash binding\n");
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of_probe = of_get_property(dp, "probe-type", NULL);
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if (!of_probe) {
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for (i = 0; i < ARRAY_SIZE(rom_probe_types); i++) {
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mtd = do_map_probe(rom_probe_types[i], map);
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if (mtd)
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return mtd;
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}
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return NULL;
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} else if (strcmp(of_probe, "CFI") == 0) {
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return do_map_probe("cfi_probe", map);
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} else if (strcmp(of_probe, "JEDEC") == 0) {
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return do_map_probe("jedec_probe", map);
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} else {
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if (strcmp(of_probe, "ROM") != 0)
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dev_dbg(&dev->dev, "obsolete_probe: don't know probe type "
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"'%s', mapping as rom\n", of_probe);
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return do_map_probe("mtd_rom", map);
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}
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}
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static int __devinit of_physmap_probe(struct of_device *dev, const struct of_device_id *match)
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{
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struct device_node *dp = dev->node;
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struct resource res;
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struct physmap_flash_info *info;
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const char **probe_type;
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const char *of_probe;
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const char *probe_type = (const char *)match->data;
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const u32 *width;
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int err;
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if (of_address_to_resource(dp, 0, &res)) {
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dev_err(&dev->dev, "Can't get the flash mapping!\n");
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err = -EINVAL;
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@ -174,21 +290,11 @@ static int __devinit of_physmap_probe(struct of_device *dev, const struct of_dev
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simple_map_init(&info->map);
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of_probe = of_get_property(dp, "probe-type", NULL);
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if (of_probe == NULL) {
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probe_type = rom_probe_types;
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for (; info->mtd == NULL && *probe_type != NULL; probe_type++)
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info->mtd = do_map_probe(*probe_type, &info->map);
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} else if (!strcmp(of_probe, "CFI"))
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info->mtd = do_map_probe("cfi_probe", &info->map);
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else if (!strcmp(of_probe, "JEDEC"))
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info->mtd = do_map_probe("jedec_probe", &info->map);
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else {
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if (strcmp(of_probe, "ROM"))
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dev_dbg(&dev->dev, "map_probe: don't know probe type "
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"'%s', mapping as rom\n", of_probe);
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info->mtd = do_map_probe("mtd_rom", &info->map);
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}
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if (probe_type)
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info->mtd = do_map_probe(probe_type, &info->map);
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else
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info->mtd = obsolete_probe(dev, &info->map);
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if (info->mtd == NULL) {
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dev_err(&dev->dev, "map_probe failed\n");
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err = -ENXIO;
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|
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@ -196,19 +302,7 @@ static int __devinit of_physmap_probe(struct of_device *dev, const struct of_dev
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}
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info->mtd->owner = THIS_MODULE;
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#ifdef CONFIG_MTD_PARTITIONS
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err = parse_mtd_partitions(info->mtd, part_probe_types, &info->parts, 0);
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if (err > 0) {
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add_mtd_partitions(info->mtd, info->parts, err);
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} else if ((err = parse_flash_partitions(dp, &info->parts)) > 0) {
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dev_info(&dev->dev, "Using OF partition information\n");
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add_mtd_partitions(info->mtd, info->parts, err);
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info->nr_parts = err;
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} else
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#endif
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add_mtd_device(info->mtd);
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return 0;
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return process_partitions(info, dev);
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err_out:
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of_physmap_remove(dev);
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|
|
@ -220,6 +314,21 @@ static int __devinit of_physmap_probe(struct of_device *dev, const struct of_dev
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}
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|
||||
static struct of_device_id of_physmap_match[] = {
|
||||
{
|
||||
.compatible = "cfi-flash",
|
||||
.data = (void *)"cfi_probe",
|
||||
},
|
||||
{
|
||||
/* FIXME: JEDEC chips can't be safely and reliably
|
||||
* probed, although the mtd code gets it right in
|
||||
* practice most of the time. We should use the
|
||||
* vendor and device ids specified by the binding to
|
||||
* bypass the heuristic probe code, but the mtd layer
|
||||
* provides, at present, no interface for doing so
|
||||
* :(. */
|
||||
.compatible = "jedec-flash",
|
||||
.data = (void *)"jedec_probe",
|
||||
},
|
||||
{
|
||||
.type = "rom",
|
||||
.compatible = "direct-mapped"
|
||||
|
|
|
|||
Loading…
Reference in a new issue