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Diffstat (limited to 'arch/cris/arch-v10/drivers/axisflashmap.c')
-rw-r--r--arch/cris/arch-v10/drivers/axisflashmap.c432
1 files changed, 432 insertions, 0 deletions
diff --git a/arch/cris/arch-v10/drivers/axisflashmap.c b/arch/cris/arch-v10/drivers/axisflashmap.c
new file mode 100644
index 000000000..a4bbdfd37
--- /dev/null
+++ b/arch/cris/arch-v10/drivers/axisflashmap.c
@@ -0,0 +1,432 @@
+/*
+ * Physical mapping layer for MTD using the Axis partitiontable format
+ *
+ * Copyright (c) 2001, 2002 Axis Communications AB
+ *
+ * This file is under the GPL.
+ *
+ * First partition is always sector 0 regardless of if we find a partitiontable
+ * or not. In the start of the next sector, there can be a partitiontable that
+ * tells us what other partitions to define. If there isn't, we use a default
+ * partition split defined below.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+
+#include <linux/mtd/concat.h>
+#include <linux/mtd/map.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/mtdram.h>
+#include <linux/mtd/partitions.h>
+
+#include <asm/axisflashmap.h>
+#include <asm/mmu.h>
+#include <arch/sv_addr_ag.h>
+
+#ifdef CONFIG_CRIS_LOW_MAP
+#define FLASH_UNCACHED_ADDR KSEG_8
+#define FLASH_CACHED_ADDR KSEG_5
+#else
+#define FLASH_UNCACHED_ADDR KSEG_E
+#define FLASH_CACHED_ADDR KSEG_F
+#endif
+
+#if CONFIG_ETRAX_FLASH_BUSWIDTH==1
+#define flash_data __u8
+#elif CONFIG_ETRAX_FLASH_BUSWIDTH==2
+#define flash_data __u16
+#elif CONFIG_ETRAX_FLASH_BUSWIDTH==4
+#define flash_data __u32
+#endif
+
+/* From head.S */
+extern unsigned long romfs_start, romfs_length, romfs_in_flash;
+
+/* The master mtd for the entire flash. */
+struct mtd_info* axisflash_mtd = NULL;
+
+/* Map driver functions. */
+
+static map_word flash_read(struct map_info *map, unsigned long ofs)
+{
+ map_word tmp;
+ tmp.x[0] = *(flash_data *)(map->map_priv_1 + ofs);
+ return tmp;
+}
+
+static void flash_copy_from(struct map_info *map, void *to,
+ unsigned long from, ssize_t len)
+{
+ memcpy(to, (void *)(map->map_priv_1 + from), len);
+}
+
+static void flash_write(struct map_info *map, map_word d, unsigned long adr)
+{
+ *(flash_data *)(map->map_priv_1 + adr) = (flash_data)d.x[0];
+}
+
+/*
+ * The map for chip select e0.
+ *
+ * We run into tricky coherence situations if we mix cached with uncached
+ * accesses to we only use the uncached version here.
+ *
+ * The size field is the total size where the flash chips may be mapped on the
+ * chip select. MTD probes should find all devices there and it does not matter
+ * if there are unmapped gaps or aliases (mirrors of flash devices). The MTD
+ * probes will ignore them.
+ *
+ * The start address in map_priv_1 is in virtual memory so we cannot use
+ * MEM_CSE0_START but must rely on that FLASH_UNCACHED_ADDR is the start
+ * address of cse0.
+ */
+static struct map_info map_cse0 = {
+ .name = "cse0",
+ .size = MEM_CSE0_SIZE,
+ .bankwidth = CONFIG_ETRAX_FLASH_BUSWIDTH,
+ .read = flash_read,
+ .copy_from = flash_copy_from,
+ .write = flash_write,
+ .map_priv_1 = FLASH_UNCACHED_ADDR
+};
+
+/*
+ * The map for chip select e1.
+ *
+ * If there was a gap between cse0 and cse1, map_priv_1 would get the wrong
+ * address, but there isn't.
+ */
+static struct map_info map_cse1 = {
+ .name = "cse1",
+ .size = MEM_CSE1_SIZE,
+ .bankwidth = CONFIG_ETRAX_FLASH_BUSWIDTH,
+ .read = flash_read,
+ .copy_from = flash_copy_from,
+ .write = flash_write,
+ .map_priv_1 = FLASH_UNCACHED_ADDR + MEM_CSE0_SIZE
+};
+
+/* If no partition-table was found, we use this default-set. */
+#define MAX_PARTITIONS 7
+#define NUM_DEFAULT_PARTITIONS 3
+
+/*
+ * Default flash size is 2MB. CONFIG_ETRAX_PTABLE_SECTOR is most likely the
+ * size of one flash block and "filesystem"-partition needs 5 blocks to be able
+ * to use JFFS.
+ */
+static struct mtd_partition axis_default_partitions[NUM_DEFAULT_PARTITIONS] = {
+ {
+ .name = "boot firmware",
+ .size = CONFIG_ETRAX_PTABLE_SECTOR,
+ .offset = 0
+ },
+ {
+ .name = "kernel",
+ .size = 0x200000 - (6 * CONFIG_ETRAX_PTABLE_SECTOR),
+ .offset = CONFIG_ETRAX_PTABLE_SECTOR
+ },
+ {
+ .name = "filesystem",
+ .size = 5 * CONFIG_ETRAX_PTABLE_SECTOR,
+ .offset = 0x200000 - (5 * CONFIG_ETRAX_PTABLE_SECTOR)
+ }
+};
+
+/* Initialize the ones normally used. */
+static struct mtd_partition axis_partitions[MAX_PARTITIONS] = {
+ {
+ .name = "part0",
+ .size = CONFIG_ETRAX_PTABLE_SECTOR,
+ .offset = 0
+ },
+ {
+ .name = "part1",
+ .size = 0,
+ .offset = 0
+ },
+ {
+ .name = "part2",
+ .size = 0,
+ .offset = 0
+ },
+ {
+ .name = "part3",
+ .size = 0,
+ .offset = 0
+ },
+ {
+ .name = "part4",
+ .size = 0,
+ .offset = 0
+ },
+ {
+ .name = "part5",
+ .size = 0,
+ .offset = 0
+ },
+ {
+ .name = "part6",
+ .size = 0,
+ .offset = 0
+ },
+};
+
+#ifdef CONFIG_ETRAX_AXISFLASHMAP_MTD0WHOLE
+/* Main flash device */
+static struct mtd_partition main_partition = {
+ .name = "main",
+ .size = 0,
+ .offset = 0
+};
+#endif
+
+/*
+ * Probe a chip select for AMD-compatible (JEDEC) or CFI-compatible flash
+ * chips in that order (because the amd_flash-driver is faster).
+ */
+static struct mtd_info *probe_cs(struct map_info *map_cs)
+{
+ struct mtd_info *mtd_cs = NULL;
+
+ printk(KERN_INFO
+ "%s: Probing a 0x%08lx bytes large window at 0x%08lx.\n",
+ map_cs->name, map_cs->size, map_cs->map_priv_1);
+
+#ifdef CONFIG_MTD_CFI
+ mtd_cs = do_map_probe("cfi_probe", map_cs);
+#endif
+#ifdef CONFIG_MTD_JEDECPROBE
+ if (!mtd_cs)
+ mtd_cs = do_map_probe("jedec_probe", map_cs);
+#endif
+
+ return mtd_cs;
+}
+
+/*
+ * Probe each chip select individually for flash chips. If there are chips on
+ * both cse0 and cse1, the mtd_info structs will be concatenated to one struct
+ * so that MTD partitions can cross chip boundries.
+ *
+ * The only known restriction to how you can mount your chips is that each
+ * chip select must hold similar flash chips. But you need external hardware
+ * to do that anyway and you can put totally different chips on cse0 and cse1
+ * so it isn't really much of a restriction.
+ */
+static struct mtd_info *flash_probe(void)
+{
+ struct mtd_info *mtd_cse0;
+ struct mtd_info *mtd_cse1;
+ struct mtd_info *mtd_cse;
+
+ mtd_cse0 = probe_cs(&map_cse0);
+ mtd_cse1 = probe_cs(&map_cse1);
+
+ if (!mtd_cse0 && !mtd_cse1) {
+ /* No chip found. */
+ return NULL;
+ }
+
+ if (mtd_cse0 && mtd_cse1) {
+ struct mtd_info *mtds[] = { mtd_cse0, mtd_cse1 };
+
+ /* Since the concatenation layer adds a small overhead we
+ * could try to figure out if the chips in cse0 and cse1 are
+ * identical and reprobe the whole cse0+cse1 window. But since
+ * flash chips are slow, the overhead is relatively small.
+ * So we use the MTD concatenation layer instead of further
+ * complicating the probing procedure.
+ */
+ mtd_cse = mtd_concat_create(mtds, ARRAY_SIZE(mtds),
+ "cse0+cse1");
+ if (!mtd_cse) {
+ printk(KERN_ERR "%s and %s: Concatenation failed!\n",
+ map_cse0.name, map_cse1.name);
+
+ /* The best we can do now is to only use what we found
+ * at cse0.
+ */
+ mtd_cse = mtd_cse0;
+ map_destroy(mtd_cse1);
+ }
+ } else {
+ mtd_cse = mtd_cse0? mtd_cse0 : mtd_cse1;
+ }
+
+ return mtd_cse;
+}
+
+/*
+ * Probe the flash chip(s) and, if it succeeds, read the partition-table
+ * and register the partitions with MTD.
+ */
+static int __init init_axis_flash(void)
+{
+ struct mtd_info *mymtd;
+ int err = 0;
+ int pidx = 0;
+ struct partitiontable_head *ptable_head = NULL;
+ struct partitiontable_entry *ptable;
+ int use_default_ptable = 1; /* Until proven otherwise. */
+ const char pmsg[] = " /dev/flash%d at 0x%08x, size 0x%08x\n";
+
+ if (!(mymtd = flash_probe())) {
+ /* There's no reason to use this module if no flash chip can
+ * be identified. Make sure that's understood.
+ */
+ printk(KERN_INFO "axisflashmap: Found no flash chip.\n");
+ } else {
+ printk(KERN_INFO "%s: 0x%08x bytes of flash memory.\n",
+ mymtd->name, mymtd->size);
+ axisflash_mtd = mymtd;
+ }
+
+ if (mymtd) {
+ mymtd->owner = THIS_MODULE;
+ ptable_head = (struct partitiontable_head *)(FLASH_CACHED_ADDR +
+ CONFIG_ETRAX_PTABLE_SECTOR +
+ PARTITION_TABLE_OFFSET);
+ }
+ pidx++; /* First partition is always set to the default. */
+
+ if (ptable_head && (ptable_head->magic == PARTITION_TABLE_MAGIC)
+ && (ptable_head->size <
+ (MAX_PARTITIONS * sizeof(struct partitiontable_entry) +
+ PARTITIONTABLE_END_MARKER_SIZE))
+ && (*(unsigned long*)((void*)ptable_head + sizeof(*ptable_head) +
+ ptable_head->size -
+ PARTITIONTABLE_END_MARKER_SIZE)
+ == PARTITIONTABLE_END_MARKER)) {
+ /* Looks like a start, sane length and end of a
+ * partition table, lets check csum etc.
+ */
+ int ptable_ok = 0;
+ struct partitiontable_entry *max_addr =
+ (struct partitiontable_entry *)
+ ((unsigned long)ptable_head + sizeof(*ptable_head) +
+ ptable_head->size);
+ unsigned long offset = CONFIG_ETRAX_PTABLE_SECTOR;
+ unsigned char *p;
+ unsigned long csum = 0;
+
+ ptable = (struct partitiontable_entry *)
+ ((unsigned long)ptable_head + sizeof(*ptable_head));
+
+ /* Lets be PARANOID, and check the checksum. */
+ p = (unsigned char*) ptable;
+
+ while (p <= (unsigned char*)max_addr) {
+ csum += *p++;
+ csum += *p++;
+ csum += *p++;
+ csum += *p++;
+ }
+ ptable_ok = (csum == ptable_head->checksum);
+
+ /* Read the entries and use/show the info. */
+ printk(KERN_INFO " Found a%s partition table at 0x%p-0x%p.\n",
+ (ptable_ok ? " valid" : "n invalid"), ptable_head,
+ max_addr);
+
+ /* We have found a working bootblock. Now read the
+ * partition table. Scan the table. It ends when
+ * there is 0xffffffff, that is, empty flash.
+ */
+ while (ptable_ok
+ && ptable->offset != 0xffffffff
+ && ptable < max_addr
+ && pidx < MAX_PARTITIONS) {
+
+ axis_partitions[pidx].offset = offset + ptable->offset;
+ axis_partitions[pidx].size = ptable->size;
+
+ printk(pmsg, pidx, axis_partitions[pidx].offset,
+ axis_partitions[pidx].size);
+ pidx++;
+ ptable++;
+ }
+ use_default_ptable = !ptable_ok;
+ }
+
+ if (romfs_in_flash) {
+ /* Add an overlapping device for the root partition (romfs). */
+
+ axis_partitions[pidx].name = "romfs";
+ axis_partitions[pidx].size = romfs_length;
+ axis_partitions[pidx].offset = romfs_start - FLASH_CACHED_ADDR;
+ axis_partitions[pidx].mask_flags |= MTD_WRITEABLE;
+
+ printk(KERN_INFO
+ " Adding readonly flash partition for romfs image:\n");
+ printk(pmsg, pidx, axis_partitions[pidx].offset,
+ axis_partitions[pidx].size);
+ pidx++;
+ }
+
+#ifdef CONFIG_ETRAX_AXISFLASHMAP_MTD0WHOLE
+ if (mymtd) {
+ main_partition.size = mymtd->size;
+ err = mtd_device_register(mymtd, &main_partition, 1);
+ if (err)
+ panic("axisflashmap: Could not initialize "
+ "partition for whole main mtd device!\n");
+ }
+#endif
+
+ if (mymtd) {
+ if (use_default_ptable) {
+ printk(KERN_INFO " Using default partition table.\n");
+ err = mtd_device_register(mymtd,
+ axis_default_partitions,
+ NUM_DEFAULT_PARTITIONS);
+ } else {
+ err = mtd_device_register(mymtd, axis_partitions,
+ pidx);
+ }
+
+ if (err)
+ panic("axisflashmap could not add MTD partitions!\n");
+ }
+
+ if (!romfs_in_flash) {
+ /* Create an RAM device for the root partition (romfs). */
+
+#if !defined(CONFIG_MTD_MTDRAM) || (CONFIG_MTDRAM_TOTAL_SIZE != 0) || (CONFIG_MTDRAM_ABS_POS != 0)
+ /* No use trying to boot this kernel from RAM. Panic! */
+ printk(KERN_EMERG "axisflashmap: Cannot create an MTD RAM "
+ "device due to kernel (mis)configuration!\n");
+ panic("This kernel cannot boot from RAM!\n");
+#else
+ struct mtd_info *mtd_ram;
+
+ mtd_ram = kmalloc(sizeof(struct mtd_info), GFP_KERNEL);
+ if (!mtd_ram)
+ panic("axisflashmap couldn't allocate memory for "
+ "mtd_info!\n");
+
+ printk(KERN_INFO " Adding RAM partition for romfs image:\n");
+ printk(pmsg, pidx, (unsigned)romfs_start,
+ (unsigned)romfs_length);
+
+ err = mtdram_init_device(mtd_ram,
+ (void *)romfs_start,
+ romfs_length,
+ "romfs");
+ if (err)
+ panic("axisflashmap could not initialize MTD RAM "
+ "device!\n");
+#endif
+ }
+ return err;
+}
+
+/* This adds the above to the kernels init-call chain. */
+module_init(init_axis_flash);
+
+EXPORT_SYMBOL(axisflash_mtd);
generated by cgit v1.2.3-54-g00ecf (git 2.45.2) at 2024-07-02 09:04:56 +0000