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/*
* Common Flash Interface support:
* Generic utility functions not dependent on command set
*
* Copyright (C) 2002 Red Hat
* Copyright (C) 2003 STMicroelectronics Limited
*
* This code is covered by the GPL.
*/
#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <asm/io.h>
#include <asm/byteorder.h>
#include <linux/errno.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/mtd/xip.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/map.h>
#include <linux/mtd/cfi.h>
void cfi_udelay(int us)
{
if (us >= 1000) {
msleep(DIV_ROUND_UP(us, 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
/* fall through */
case 4:
onecmd |= (onecmd << (chip_mode * 16));
/* fall through */
case 2:
onecmd |= (onecmd << (chip_mode * 8));
/* fall through */
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
/* fall through */
case 4:
res |= (onestat >> (chip_mode * 16));
/* fall through */
case 2:
res |= (onestat >> (chip_mode * 8));
/* fall through */
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)
{
int osf = cfi->interleave * cfi->device_type; /* scale factor */
map_word val[3];
map_word qry[3];
qry[0] = cfi_build_cmd('Q', map, cfi);
qry[1] = cfi_build_cmd('R', map, cfi);
qry[2] = cfi_build_cmd('Y', map, cfi);
val[0] = map_read(map, base + osf*0x10);
val[1] = map_read(map, base + osf*0x11);
val[2] = map_read(map, base + osf*0x12);
if (!map_word_equal(map, qry[0], val[0]))
return 0;
if (!map_word_equal(map, qry[1], val[1]))
return 0;
if (!map_word_equal(map, qry[2], val[2]))
return 0;
return 1; /* "QRY" found */
}
EXPORT_SYMBOL_GPL(cfi_qry_present);
int __xipram cfi_qry_mode_on(uint32_t base, struct map_info *map,
struct cfi_private *cfi)
{
cfi_send_gen_cmd(0xF0, 0, base, map, cfi, cfi->device_type, NULL);
cfi_send_gen_cmd(0x98, 0x55, base, map, cfi, cfi->device_type, NULL);
if (cfi_qry_present(map, base, cfi))
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