Gitweb:     
http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=2099172d61abda1b793b499bb8edcaac4de2cdae
Commit:     2099172d61abda1b793b499bb8edcaac4de2cdae
Parent:     3c607ce2a3213f33b8b6b854b5f7db876021e466
Author:     David Gibson <[EMAIL PROTECTED]>
AuthorDate: Fri Sep 7 13:23:53 2007 +1000
Committer:  Paul Mackerras <[EMAIL PROTECTED]>
CommitDate: Fri Sep 14 01:33:25 2007 +1000

    [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 <[EMAIL PROTECTED]>
    Acked-by: Segher Boessenkool <[EMAIL PROTECTED]>
    Signed-off-by: Paul Mackerras <[EMAIL PROTECTED]>
---
 Documentation/powerpc/booting-without-of.txt |   92 ++++++----
 arch/powerpc/boot/dts/ebony.dts              |   30 ++--
 drivers/mtd/maps/physmap_of.c                |  239 +++++++++++++++++++-------
 3 files changed, 251 insertions(+), 110 deletions(-)

diff --git a/Documentation/powerpc/booting-without-of.txt 
b/Documentation/powerpc/booting-without-of.txt
index 76733a3..20e0e6c 100644
--- a/Documentation/powerpc/booting-without-of.txt
+++ b/Documentation/powerpc/booting-without-of.txt
@@ -50,7 +50,7 @@ Table of Contents
       g) Freescale SOC SEC Security Engines
       h) Board Control and Status (BCSR)
       i) Freescale QUICC Engine module (QE)
-      j) Flash chip nodes
+      j) CFI or JEDEC memory-mapped NOR flash
       k) Global Utilities Block
 
   VII - Specifying interrupt information for devices
@@ -1757,45 +1757,69 @@ platforms are moved over to use the 
flattened-device-tree model.
                };
        };
 
-    j) Flash chip nodes
+   j) CFI or JEDEC memory-mapped NOR flash
 
     Flash chips (Memory Technology Devices) are often used for solid state
     file systems on embedded devices.
 
-    Required properties:
+     - compatible : should contain the specific model of flash chip(s)
+       used, if known, followed by either "cfi-flash" or "jedec-flash"
+     - reg : Address range of the flash chip
+     - bank-width : Width (in bytes) of the flash bank.  Equal to the
+       device width times the number of interleaved chips.
+     - device-width : (optional) Width of a single flash chip.  If
+       omitted, assumed to be equal to 'bank-width'.
+     - #address-cells, #size-cells : Must be present if the flash has
+       sub-nodes representing partitions (see below).  In this case
+       both #address-cells and #size-cells must be equal to 1.
+
+    For JEDEC compatible devices, the following additional properties
+    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
+    device tree may optionally contain additional information
+    describing partitions of the flash 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
+    use an on-flash partition table such as RedBoot.
+
+    Each partition is represented as a sub-node of the flash device.
+    Each node's name represents the name of the corresponding
+    partition of the flash device.
+
+    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.
 
-     - device_type : has to be "rom"
-     - compatible : Should specify what this flash device is compatible with.
-       Currently, this is most likely to be "direct-mapped" (which
-       corresponds to the MTD physmap mapping driver).
-     - reg : Offset and length of the register set (or memory mapping) for
-       the device.
-     - bank-width : Width of the flash data bus in bytes. Required
-       for the NOR flashes (compatible == "direct-mapped" and others) ONLY.
-
-    Recommended properties :
-
-     - partitions : Several pairs of 32-bit values where the first value is
-       partition's offset from the start of the device and the second one is
-       partition size in bytes with LSB used to signify a read only
-       partition (so, the partition size should always be an even number).
-     - partition-names : The list of concatenated zero terminated strings
-       representing the partition names.
-     - probe-type : The type of probe which should be done for the chip
-       (JEDEC vs CFI actually). Valid ONLY for NOR flashes.
-
-   Example:
+    Example:
 
-       [EMAIL PROTECTED] {
-               device_type = "rom";
-               compatible = "direct-mapped";
-               probe-type = "CFI";
-               reg = <ff000000 01000000>;
-               bank-width = <4>;
-               partitions = <00000000 00f80000
-                             00f80000 00080001>;
-               partition-names = "fs\0firmware";
-       };
+       [EMAIL PROTECTED] {
+               compatible = "amd,am29lv128ml", "cfi-flash";
+               reg = <ff000000 01000000>;
+               bank-width = <4>;
+               device-width = <1>;
+               #address-cells = <1>;
+               #size-cells = <1>;
+               [EMAIL PROTECTED] {
+                       label = "fs";
+                       reg = <0 f80000>;
+               };
+               [EMAIL PROTECTED] {
+                       label ="firmware";
+                       reg = <f80000 80000>;
+                       read-only;
+               };
+       };
 
    k) Global Utilities Block
 
diff --git a/arch/powerpc/boot/dts/ebony.dts b/arch/powerpc/boot/dts/ebony.dts
index 37599bd..bc25997 100644
--- a/arch/powerpc/boot/dts/ebony.dts
+++ b/arch/powerpc/boot/dts/ebony.dts
@@ -138,13 +138,16 @@
                                interrupt-parent = <&UIC1>;
 
                                [EMAIL PROTECTED],80000 {
-                                       device_type = "rom";
-                                       compatible = "direct-mapped";
-                                       probe-type = "JEDEC";
+                                       compatible = "jedec-flash";
                                        bank-width = <1>;
-                                       partitions = <0 80000>;
-                                       partition-names = "OpenBIOS";
                                        reg = <0 80000 80000>;
+                                       #address-cells = <1>;
+                                       #size-cells = <1>;
+                                       [EMAIL PROTECTED] {
+                                               label = "OpenBIOS";
+                                               reg = <0 80000>;
+                                               read-only;
+                                       };
                                };
 
                                [EMAIL PROTECTED],0 {
@@ -154,14 +157,19 @@
                                };
 
                                [EMAIL PROTECTED],0 {
-                                       device_type = "rom";
-                                       compatible = "direct-mapped";
-                                       probe-type = "JEDEC";
+                                       compatible = "jedec-flash";
                                        bank-width = <1>;
-                                       partitions = <0 380000
-                                                     380000 80000>;
-                                       partition-names = "fs", "firmware";
                                        reg = <2 0 400000>;
+                                       #address-cells = <1>;
+                                       #size-cells = <1>;
+                                       [EMAIL PROTECTED] {
+                                               label = "fs";
+                                               reg = <0 380000>;
+                                       };
+                                       [EMAIL PROTECTED] {
+                                               label = "firmware";
+                                               reg = <380000 80000>;
+                                       };
                                };
 
                                [EMAIL PROTECTED],0 {
diff --git a/drivers/mtd/maps/physmap_of.c b/drivers/mtd/maps/physmap_of.c
index bbb42c3..3df001b 100644
--- a/drivers/mtd/maps/physmap_of.c
+++ b/drivers/mtd/maps/physmap_of.c
@@ -4,6 +4,9 @@
  * Copyright (C) 2006 MontaVista Software Inc.
  * Author: Vitaly Wool <[EMAIL PROTECTED]>
  *
+ * Revised to handle newer style flash binding by:
+ *   Copyright (C) 2007 David Gibson, IBM Corporation.
+ *
  * This program is free software; you can redistribute  it and/or modify it
  * under  the terms of  the GNU General  Public License as published by the
  * Free Software Foundation;  either version 2 of the  License, or (at your
@@ -30,56 +33,135 @@ struct physmap_flash_info {
        struct map_info         map;
        struct resource         *res;
 #ifdef CONFIG_MTD_PARTITIONS
-       int                     nr_parts;
        struct mtd_partition    *parts;
 #endif
 };
 
-static const char *rom_probe_types[] = { "cfi_probe", "jedec_probe", 
"map_rom", NULL };
-#ifdef CONFIG_MTD_PARTITIONS
-static const char *part_probe_types[] = { "cmdlinepart", "RedBoot", NULL };
-#endif
-
 #ifdef CONFIG_MTD_PARTITIONS
-static int parse_flash_partitions(struct device_node *node,
-               struct mtd_partition **parts)
+static int parse_obsolete_partitions(struct of_device *dev,
+                                    struct physmap_flash_info *info,
+                                    struct device_node *dp)
 {
-       int i, plen, retval = -ENOMEM;
-       const  u32  *part;
-       const  char *name;
+       int i, plen, nr_parts;
+       const struct {
+               u32 offset, len;
+       } *part;
+       const char *names;
 
-       part = of_get_property(node, "partitions", &plen);
-       if (part == NULL)
-               goto err;
+       part = of_get_property(dp, "partitions", &plen);
+       if (!part)
+               return -ENOENT;
 
-       retval = plen / (2 * sizeof(u32));
-       *parts = kzalloc(retval * sizeof(struct mtd_partition), GFP_KERNEL);
-       if (*parts == NULL) {
+       dev_warn(&dev->dev, "Device tree uses obsolete partition map 
binding\n");
+
+       nr_parts = plen / sizeof(part[0]);
+
+       info->parts = kzalloc(nr_parts * sizeof(struct mtd_partition), 
GFP_KERNEL);
+       if (!info->parts) {
                printk(KERN_ERR "Can't allocate the flash partition data!\n");
-               goto err;
+               return -ENOMEM;
        }
 
-       name = of_get_property(node, "partition-names", &plen);
+       names = of_get_property(dp, "partition-names", &plen);
 
-       for (i = 0; i < retval; i++) {
-               (*parts)[i].offset = *part++;
-               (*parts)[i].size   = *part & ~1;
-               if (*part++ & 1) /* bit 0 set signifies read only partition */
-                       (*parts)[i].mask_flags = MTD_WRITEABLE;
+       for (i = 0; i < nr_parts; i++) {
+               info->parts[i].offset = part->offset;
+               info->parts[i].size   = part->len & ~1;
+               if (part->len & 1) /* bit 0 set signifies read only partition */
+                       info->parts[i].mask_flags = MTD_WRITEABLE;
 
-               if (name != NULL && plen > 0) {
-                       int len = strlen(name) + 1;
+               if (names && (plen > 0)) {
+                       int len = strlen(names) + 1;
 
-                       (*parts)[i].name = (char *)name;
+                       info->parts[i].name = (char *)names;
                        plen -= len;
-                       name += len;
-               } else
-                       (*parts)[i].name = "unnamed";
+                       names += len;
+               } else {
+                       info->parts[i].name = "unnamed";
+               }
+
+               part++;
        }
-err:
-       return retval;
+
+       return nr_parts;
 }
-#endif
+
+static int __devinit process_partitions(struct physmap_flash_info *info,
+                                       struct of_device *dev)
+{
+       const char *partname;
+       static const char *part_probe_types[]
+               = { "cmdlinepart", "RedBoot", NULL };
+       struct device_node *dp = dev->node, *pp;
+       int nr_parts, i;
+
+       /* First look for RedBoot table or partitions on the command
+        * line, these take precedence over device tree information */
+       nr_parts = parse_mtd_partitions(info->mtd, part_probe_types,
+                                       &info->parts, 0);
+       if (nr_parts > 0) {
+               add_mtd_partitions(info->mtd, info->parts, nr_parts);
+               return 0;
+       }
+
+       /* First count the subnodes */
+       nr_parts = 0;
+       for (pp = dp->child; pp; pp = pp->sibling)
+               nr_parts++;
+
+       if (nr_parts) {
+               info->parts = kzalloc(nr_parts * sizeof(struct mtd_partition),
+                                     GFP_KERNEL);
+               if (!info->parts) {
+                       printk(KERN_ERR "Can't allocate the flash partition 
data!\n");
+                       return -ENOMEM;
+               }
+
+               for (pp = dp->child, i = 0 ; pp; pp = pp->sibling, i++) {
+                       const u32 *reg;
+                       int len;
+
+                       reg = of_get_property(pp, "reg", &len);
+                       if (!reg || (len != 2*sizeof(u32))) {
+                               dev_err(&dev->dev, "Invalid 'reg' on %s\n",
+                                       dp->full_name);
+                               kfree(info->parts);
+                               info->parts = NULL;
+                               return -EINVAL;
+                       }
+                       info->parts[i].offset = reg[0];
+                       info->parts[i].size = reg[1];
+
+                       partname = of_get_property(pp, "label", &len);
+                       if (!partname)
+                               partname = of_get_property(pp, "name", &len);
+                       info->parts[i].name = (char *)partname;
+
+                       if (of_get_property(pp, "read-only", &len))
+                               info->parts[i].mask_flags = MTD_WRITEABLE;
+               }
+       } else {
+               nr_parts = parse_obsolete_partitions(dev, info, dp);
+       }
+
+       if (nr_parts < 0)
+               return nr_parts;
+
+       if (nr_parts > 0)
+               add_mtd_partitions(info->mtd, info->parts, nr_parts);
+       else
+               add_mtd_device(info->mtd);
+
+       return 0;
+}
+#else /* MTD_PARTITIONS */
+static int __devinit process_partitions(struct physmap_flash_info *info,
+                                       struct device_node *dev)
+{
+       add_mtd_device(info->mtd);
+       return 0;
+}
+#endif /* MTD_PARTITIONS */
 
 static int of_physmap_remove(struct of_device *dev)
 {
@@ -92,7 +174,7 @@ static int of_physmap_remove(struct of_device *dev)
 
        if (info->mtd != NULL) {
 #ifdef CONFIG_MTD_PARTITIONS
-               if (info->nr_parts) {
+               if (info->parts) {
                        del_mtd_partitions(info->mtd);
                        kfree(info->parts);
                } else {
@@ -115,17 +197,51 @@ static int of_physmap_remove(struct of_device *dev)
        return 0;
 }
 
+/* Helper function to handle probing of the obsolete "direct-mapped"
+ * compatible binding, which has an extra "probe-type" property
+ * describing the type of flash probe necessary. */
+static struct mtd_info * __devinit obsolete_probe(struct of_device *dev,
+                                                 struct map_info *map)
+{
+       struct device_node *dp = dev->node;
+       const char *of_probe;
+       struct mtd_info *mtd;
+       static const char *rom_probe_types[]
+               = { "cfi_probe", "jedec_probe", "map_rom"};
+       int i;
+
+       dev_warn(&dev->dev, "Device tree uses obsolete \"direct-mapped\" "
+                "flash binding\n");
+
+       of_probe = of_get_property(dp, "probe-type", NULL);
+       if (!of_probe) {
+               for (i = 0; i < ARRAY_SIZE(rom_probe_types); i++) {
+                       mtd = do_map_probe(rom_probe_types[i], map);
+                       if (mtd)
+                               return mtd;
+               }
+               return NULL;
+       } else if (strcmp(of_probe, "CFI") == 0) {
+               return do_map_probe("cfi_probe", map);
+       } else if (strcmp(of_probe, "JEDEC") == 0) {
+               return do_map_probe("jedec_probe", map);
+       } else {
+               if (strcmp(of_probe, "ROM") != 0)
+                       dev_dbg(&dev->dev, "obsolete_probe: don't know probe 
type "
+                               "'%s', mapping as rom\n", of_probe);
+               return do_map_probe("mtd_rom", map);
+       }
+}
+
 static int __devinit of_physmap_probe(struct of_device *dev, const struct 
of_device_id *match)
 {
        struct device_node *dp = dev->node;
        struct resource res;
        struct physmap_flash_info *info;
-       const char **probe_type;
-       const char *of_probe;
+       const char *probe_type = (const char *)match->data;
        const u32 *width;
        int err;
 
-
        if (of_address_to_resource(dp, 0, &res)) {
                dev_err(&dev->dev, "Can't get the flash mapping!\n");
                err = -EINVAL;
@@ -174,21 +290,11 @@ static int __devinit of_physmap_probe(struct of_device 
*dev, const struct of_dev
 
        simple_map_init(&info->map);
 
-       of_probe = of_get_property(dp, "probe-type", NULL);
-       if (of_probe == NULL) {
-               probe_type = rom_probe_types;
-               for (; info->mtd == NULL && *probe_type != NULL; probe_type++)
-                       info->mtd = do_map_probe(*probe_type, &info->map);
-       } else if (!strcmp(of_probe, "CFI"))
-               info->mtd = do_map_probe("cfi_probe", &info->map);
-       else if (!strcmp(of_probe, "JEDEC"))
-               info->mtd = do_map_probe("jedec_probe", &info->map);
-       else {
-               if (strcmp(of_probe, "ROM"))
-                       dev_dbg(&dev->dev, "map_probe: don't know probe type "
-                       "'%s', mapping as rom\n", of_probe);
-               info->mtd = do_map_probe("mtd_rom", &info->map);
-       }
+       if (probe_type)
+               info->mtd = do_map_probe(probe_type, &info->map);
+       else
+               info->mtd = obsolete_probe(dev, &info->map);
+
        if (info->mtd == NULL) {
                dev_err(&dev->dev, "map_probe failed\n");
                err = -ENXIO;
@@ -196,19 +302,7 @@ static int __devinit of_physmap_probe(struct of_device 
*dev, const struct of_dev
        }
        info->mtd->owner = THIS_MODULE;
 
-#ifdef CONFIG_MTD_PARTITIONS
-       err = parse_mtd_partitions(info->mtd, part_probe_types, &info->parts, 
0);
-       if (err > 0) {
-               add_mtd_partitions(info->mtd, info->parts, err);
-       } else if ((err = parse_flash_partitions(dp, &info->parts)) > 0) {
-               dev_info(&dev->dev, "Using OF partition information\n");
-               add_mtd_partitions(info->mtd, info->parts, err);
-               info->nr_parts = err;
-       } else
-#endif
-
-       add_mtd_device(info->mtd);
-       return 0;
+       return process_partitions(info, dev);
 
 err_out:
        of_physmap_remove(dev);
@@ -221,6 +315,21 @@ err_out:
 
 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"
        },
-
To unsubscribe from this list: send the line "unsubscribe git-commits-head" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to