diff options
Diffstat (limited to 'drivers/mtd/chips/cfi_util.c')
| -rw-r--r-- | drivers/mtd/chips/cfi_util.c | 188 |
1 files changed, 188 insertions, 0 deletions
diff --git a/drivers/mtd/chips/cfi_util.c b/drivers/mtd/chips/cfi_util.c index 09c79bd0b4f4..6f16552cd59f 100644 --- a/drivers/mtd/chips/cfi_util.c +++ b/drivers/mtd/chips/cfi_util.c @@ -23,6 +23,194 @@ #include <linux/mtd/map.h> #include <linux/mtd/cfi.h> +void cfi_udelay(int us) +{ + if (us >= 1000) { + msleep((us+999)/1000); + } else { + udelay(us); + cond_resched(); + } +} +EXPORT_SYMBOL(cfi_udelay); + +/* + * Returns the command address according to the given geometry. + */ +uint32_t cfi_build_cmd_addr(uint32_t cmd_ofs, + struct map_info *map, struct cfi_private *cfi) +{ + unsigned bankwidth = map_bankwidth(map); + unsigned interleave = cfi_interleave(cfi); + unsigned type = cfi->device_type; + uint32_t addr; + + addr = (cmd_ofs * type) * interleave; + + /* Modify the unlock address if we are in compatibility mode. + * For 16bit devices on 8 bit busses + * and 32bit devices on 16 bit busses + * set the low bit of the alternating bit sequence of the address. + */ + if (((type * interleave) > bankwidth) && ((cmd_ofs & 0xff) == 0xaa)) + addr |= (type >> 1)*interleave; + + return addr; +} +EXPORT_SYMBOL(cfi_build_cmd_addr); + +/* + * Transforms the CFI command for the given geometry (bus width & interleave). + * It looks too long to be inline, but in the common case it should almost all + * get optimised away. + */ +map_word cfi_build_cmd(u_long cmd, struct map_info *map, struct cfi_private *cfi) +{ + map_word val = { {0} }; + int wordwidth, words_per_bus, chip_mode, chips_per_word; + unsigned long onecmd; + int i; + + /* We do it this way to give the compiler a fighting chance + of optimising away all the crap for 'bankwidth' larger than + an unsigned long, in the common case where that support is + disabled */ + if (map_bankwidth_is_large(map)) { + wordwidth = sizeof(unsigned long); + words_per_bus = (map_bankwidth(map)) / wordwidth; // i.e. normally 1 + } else { + wordwidth = map_bankwidth(map); + words_per_bus = 1; + } + + chip_mode = map_bankwidth(map) / cfi_interleave(cfi); + chips_per_word = wordwidth * cfi_interleave(cfi) / map_bankwidth(map); + + /* First, determine what the bit-pattern should be for a single + device, according to chip mode and endianness... */ + switch (chip_mode) { + default: BUG(); + case 1: + onecmd = cmd; + break; + case 2: + onecmd = cpu_to_cfi16(map, cmd); + break; + case 4: + onecmd = cpu_to_cfi32(map, cmd); + break; + } + + /* Now replicate it across the size of an unsigned long, or + just to the bus width as appropriate */ + switch (chips_per_word) { + default: BUG(); +#if BITS_PER_LONG >= 64 + case 8: + onecmd |= (onecmd << (chip_mode * 32)); +#endif + case 4: + onecmd |= (onecmd << (chip_mode * 16)); + case 2: + onecmd |= (onecmd << (chip_mode * 8)); + case 1: + ; + } + + /* And finally, for the multi-word case, replicate it + in all words in the structure */ + for (i=0; i < words_per_bus; i++) { + val.x[i] = onecmd; + } + + return val; +} +EXPORT_SYMBOL(cfi_build_cmd); + +unsigned long cfi_merge_status(map_word val, struct map_info *map, + struct cfi_private *cfi) +{ + int wordwidth, words_per_bus, chip_mode, chips_per_word; + unsigned long onestat, res = 0; + int i; + + /* We do it this way to give the compiler a fighting chance + of optimising away all the crap for 'bankwidth' larger than + an unsigned long, in the common case where that support is + disabled */ + if (map_bankwidth_is_large(map)) { + wordwidth = sizeof(unsigned long); + words_per_bus = (map_bankwidth(map)) / wordwidth; // i.e. normally 1 + } else { + wordwidth = map_bankwidth(map); + words_per_bus = 1; + } + + chip_mode = map_bankwidth(map) / cfi_interleave(cfi); + chips_per_word = wordwidth * cfi_interleave(cfi) / map_bankwidth(map); + + onestat = val.x[0]; + /* Or all status words together */ + for (i=1; i < words_per_bus; i++) { + onestat |= val.x[i]; + } + + res = onestat; + switch(chips_per_word) { + default: BUG(); +#if BITS_PER_LONG >= 64 + case 8: + res |= (onestat >> (chip_mode * 32)); +#endif + case 4: + res |= (onestat >> (chip_mode * 16)); + case 2: + res |= (onestat >> (chip_mode * 8)); + case 1: + ; + } + + /* Last, determine what the bit-pattern should be for a single + device, according to chip mode and endianness... */ + switch (chip_mode) { + case 1: + break; + case 2: + res = cfi16_to_cpu(map, res); + break; + case 4: + res = cfi32_to_cpu(map, res); + break; + default: BUG(); + } + return res; +} +EXPORT_SYMBOL(cfi_merge_status); + +/* + * Sends a CFI command to a bank of flash for the given geometry. + * + * Returns the offset in flash where the command was written. + * If prev_val is non-null, it will be set to the value at the command address, + * before the command was written. + */ +uint32_t cfi_send_gen_cmd(u_char cmd, uint32_t cmd_addr, uint32_t base, + struct map_info *map, struct cfi_private *cfi, + int type, map_word *prev_val) +{ + map_word val; + uint32_t addr = base + cfi_build_cmd_addr(cmd_addr, map, cfi); + val = cfi_build_cmd(cmd, map, cfi); + + if (prev_val) + *prev_val = map_read(map, addr); + + map_write(map, val, addr); + + return addr - base; +} +EXPORT_SYMBOL(cfi_send_gen_cmd); + int __xipram cfi_qry_present(struct map_info *map, __u32 base, struct cfi_private *cfi) { |