Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6
[sfrench/cifs-2.6.git] / drivers / mtd / maps / physmap_of.c
index fbd613968717e7c1d10f0c656f486b0c47031d8b..aeed9ea79714ab56454840ee34d6eb5395e60f12 100644 (file)
@@ -1,9 +1,12 @@
 /*
- * Normal mappings of chips in physical memory for OF devices
+ * Flash mappings described by the OF (or flattened) device tree
  *
  * Copyright (C) 2006 MontaVista Software Inc.
  * Author: Vitaly Wool <vwool@ru.mvista.com>
  *
+ * 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
 
 #include <linux/module.h>
 #include <linux/types.h>
-#include <linux/kernel.h>
 #include <linux/init.h>
-#include <linux/slab.h>
 #include <linux/device.h>
 #include <linux/mtd/mtd.h>
 #include <linux/mtd/map.h>
 #include <linux/mtd/partitions.h>
-#include <linux/mtd/physmap.h>
-#include <asm/io.h>
-#include <asm/prom.h>
-#include <asm/of_device.h>
-#include <asm/of_platform.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
 
-struct physmap_flash_info {
+struct of_flash {
        struct mtd_info         *mtd;
        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
+#define OF_FLASH_PARTS(info)   ((info)->parts)
 
-#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 of_flash *info,
+                                    struct device_node *dp)
 {
-       int i, plen, retval = -ENOMEM;
-       const  u32  *part;
-       const  char *name;
-
-       part = of_get_property(node, "partitions", &plen);
-       if (part == NULL)
-               goto err;
-
-       retval = plen / (2 * sizeof(u32));
-       *parts = kzalloc(retval * sizeof(struct mtd_partition), GFP_KERNEL);
-       if (*parts == NULL) {
-               printk(KERN_ERR "Can't allocate the flash partition data!\n");
-               goto err;
-       }
+       int i, plen, nr_parts;
+       const struct {
+               u32 offset, len;
+       } *part;
+       const char *names;
+
+       part = of_get_property(dp, "partitions", &plen);
+       if (!part)
+               return 0; /* No partitions found */
+
+       dev_warn(&dev->dev, "Device tree uses obsolete partition map binding\n");
+
+       nr_parts = plen / sizeof(part[0]);
+
+       info->parts = kzalloc(nr_parts * sizeof(*info->parts), GFP_KERNEL);
+       if (!info->parts)
+               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 of_physmap_remove(struct of_device *dev)
+static int __devinit parse_partitions(struct of_flash *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 == 0)
+               return parse_obsolete_partitions(dev, info, dp);
+
+       info->parts = kzalloc(nr_parts * sizeof(*info->parts),
+                             GFP_KERNEL);
+       if (!info->parts)
+               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;
+       }
+
+       return nr_parts;
+}
+#else /* MTD_PARTITIONS */
+#define        OF_FLASH_PARTS(info)            (0)
+#define parse_partitions(info, dev)    (0)
+#endif /* MTD_PARTITIONS */
+
+static int of_flash_remove(struct of_device *dev)
 {
-       struct physmap_flash_info *info;
+       struct of_flash *info;
 
        info = dev_get_drvdata(&dev->dev);
-       if (info == NULL)
+       if (!info)
                return 0;
        dev_set_drvdata(&dev->dev, NULL);
 
-       if (info->mtd != NULL) {
-#ifdef CONFIG_MTD_PARTITIONS
-               if (info->nr_parts) {
+       if (info->mtd) {
+               if (OF_FLASH_PARTS(info)) {
                        del_mtd_partitions(info->mtd);
-                       kfree(info->parts);
+                       kfree(OF_FLASH_PARTS(info));
                } else {
                        del_mtd_device(info->mtd);
                }
-#else
-               del_mtd_device(info->mtd);
-#endif
                map_destroy(info->mtd);
        }
 
-       if (info->map.virt != NULL)
+       if (info->map.virt)
                iounmap(info->map.virt);
 
-       if (info->res != NULL) {
+       if (info->res) {
                release_resource(info->res);
                kfree(info->res);
        }
@@ -115,47 +173,78 @@ static int of_physmap_remove(struct of_device *dev)
        return 0;
 }
 
-static int __devinit of_physmap_probe(struct of_device *dev, const struct of_device_id *match)
+/* 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;
-       struct resource res;
-       struct physmap_flash_info *info;
-       const char **probe_type;
        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_warn(&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_flash_probe(struct of_device *dev,
+                                   const struct of_device_id *match)
+{
+       struct device_node *dp = dev->node;
+       struct resource res;
+       struct of_flash *info;
+       const char *probe_type = match->data;
        const u32 *width;
        int err;
 
-
+       err = -ENXIO;
        if (of_address_to_resource(dp, 0, &res)) {
-               dev_err(&dev->dev, "Can't get the flash mapping!\n");
-               err = -EINVAL;
+               dev_err(&dev->dev, "Can't get IO address from device tree\n");
                goto err_out;
        }
 
-               dev_dbg(&dev->dev, "physmap flash device: %.8llx at %.8llx\n",
-           (unsigned long long)res.end - res.start + 1,
-           (unsigned long long)res.start);
+               dev_dbg(&dev->dev, "of_flash device: %.8llx-%.8llx\n",
+               (unsigned long long)res.start, (unsigned long long)res.end);
 
-       info = kzalloc(sizeof(struct physmap_flash_info), GFP_KERNEL);
-       if (info == NULL) {
-               err = -ENOMEM;
+       err = -ENOMEM;
+       info = kzalloc(sizeof(*info), GFP_KERNEL);
+       if (!info)
                goto err_out;
-       }
 
        dev_set_drvdata(&dev->dev, info);
 
+       err = -EBUSY;
        info->res = request_mem_region(res.start, res.end - res.start + 1,
-                       dev->dev.bus_id);
-       if (info->res == NULL) {
-               dev_err(&dev->dev, "Could not reserve memory region\n");
-               err = -ENOMEM;
+                                      dev->dev.bus_id);
+       if (!info->res)
                goto err_out;
-       }
 
+       err = -ENXIO;
        width = of_get_property(dp, "bank-width", NULL);
-       if (width == NULL) {
-               dev_err(&dev->dev, "Can't get the flash bank width!\n");
-               err = -EINVAL;
+       if (!width) {
+               dev_err(&dev->dev, "Can't get bank width from device tree\n");
                goto err_out;
        }
 
@@ -164,87 +253,87 @@ static int __devinit of_physmap_probe(struct of_device *dev, const struct of_dev
        info->map.size = res.end - res.start + 1;
        info->map.bankwidth = *width;
 
+       err = -ENOMEM;
        info->map.virt = ioremap(info->map.phys, info->map.size);
-       if (info->map.virt == NULL) {
-               dev_err(&dev->dev, "Failed to ioremap flash region\n");
-               err = EIO;
+       if (!info->map.virt) {
+               dev_err(&dev->dev, "Failed to ioremap() flash region\n");
                goto err_out;
        }
 
        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 (info->mtd == NULL) {
-               dev_err(&dev->dev, "map_probe failed\n");
-               err = -ENXIO;
+       if (probe_type)
+               info->mtd = do_map_probe(probe_type, &info->map);
+       else
+               info->mtd = obsolete_probe(dev, &info->map);
+
+       err = -ENXIO;
+       if (!info->mtd) {
+               dev_err(&dev->dev, "do_map_probe() failed\n");
                goto err_out;
        }
        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
+       err = parse_partitions(info, dev);
+       if (err < 0)
+               goto err_out;
+
+       if (err > 0)
+               add_mtd_partitions(info->mtd, OF_FLASH_PARTS(info), err);
+       else
+               add_mtd_device(info->mtd);
 
-       add_mtd_device(info->mtd);
        return 0;
 
 err_out:
-       of_physmap_remove(dev);
+       of_flash_remove(dev);
        return err;
 }
 
-static struct of_device_id of_physmap_match[] = {
+static struct of_device_id of_flash_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"
        },
        { },
 };
+MODULE_DEVICE_TABLE(of, of_flash_match);
 
-MODULE_DEVICE_TABLE(of, of_physmap_match);
-
-
-static struct of_platform_driver of_physmap_flash_driver = {
-       .name           = "physmap-flash",
-       .match_table    = of_physmap_match,
-       .probe          = of_physmap_probe,
-       .remove         = of_physmap_remove,
+static struct of_platform_driver of_flash_driver = {
+       .name           = "of-flash",
+       .match_table    = of_flash_match,
+       .probe          = of_flash_probe,
+       .remove         = of_flash_remove,
 };
 
-static int __init of_physmap_init(void)
+static int __init of_flash_init(void)
 {
-       return of_register_platform_driver(&of_physmap_flash_driver);
+       return of_register_platform_driver(&of_flash_driver);
 }
 
-static void __exit of_physmap_exit(void)
+static void __exit of_flash_exit(void)
 {
-       of_unregister_platform_driver(&of_physmap_flash_driver);
+       of_unregister_platform_driver(&of_flash_driver);
 }
 
-module_init(of_physmap_init);
-module_exit(of_physmap_exit);
+module_init(of_flash_init);
+module_exit(of_flash_exit);
 
 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Vitaly Wool <vwool@ru.mvista.com>");
-MODULE_DESCRIPTION("Configurable MTD map driver for OF");
+MODULE_DESCRIPTION("Device tree based MTD map driver");