diff options
Diffstat (limited to 'kernel/arch/cris/arch-v10/drivers/axisflashmap.c')
| -rw-r--r-- | kernel/arch/cris/arch-v10/drivers/axisflashmap.c | 432 |
1 files changed, 432 insertions, 0 deletions
diff --git a/kernel/arch/cris/arch-v10/drivers/axisflashmap.c b/kernel/arch/cris/arch-v10/drivers/axisflashmap.c new file mode 100644 index 000000000..a4bbdfd37 --- /dev/null +++ b/kernel/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); |