[PATCH v3 3/4] mtd: cfi_cmdset_0002: Add support for writing OTP memory
Christian Riesch
christian.riesch at omicron.at
Thu Mar 6 07:18:29 EST 2014
This patch adds support for writing the one time programmable (OTP)
memory of Micron M29EW devices.
Signed-off-by: Christian Riesch <christian.riesch at omicron.at>
---
drivers/mtd/chips/cfi_cmdset_0002.c | 67 +++++++++++++++++++++++++++++++----
1 file changed, 60 insertions(+), 7 deletions(-)
diff --git a/drivers/mtd/chips/cfi_cmdset_0002.c b/drivers/mtd/chips/cfi_cmdset_0002.c
index bf72128..5d446f8 100644
--- a/drivers/mtd/chips/cfi_cmdset_0002.c
+++ b/drivers/mtd/chips/cfi_cmdset_0002.c
@@ -68,6 +68,8 @@ static int cfi_amdstd_read_fact_prot_reg(struct mtd_info *, loff_t, size_t,
size_t *, u_char *);
static int cfi_amdstd_read_user_prot_reg(struct mtd_info *, loff_t, size_t,
size_t *, u_char *);
+static int cfi_amdstd_write_user_prot_reg(struct mtd_info *, loff_t, size_t,
+ size_t *, u_char *);
static int cfi_amdstd_panic_write(struct mtd_info *mtd, loff_t to, size_t len,
size_t *retlen, const u_char *buf);
@@ -533,6 +535,7 @@ struct mtd_info *cfi_cmdset_0002(struct map_info *map, int primary)
mtd->_read_fact_prot_reg = cfi_amdstd_read_fact_prot_reg;
mtd->_get_fact_prot_info = cfi_amdstd_get_fact_prot_info;
mtd->_get_user_prot_info = cfi_amdstd_get_user_prot_info;
+ mtd->_write_user_prot_reg = cfi_amdstd_write_user_prot_reg;
mtd->flags = MTD_CAP_NORFLASH;
mtd->name = map->name;
mtd->writesize = 1;
@@ -1262,6 +1265,40 @@ static int cfi_amdstd_secsi_read (struct mtd_info *mtd, loff_t from, size_t len,
return ret;
}
+static int __xipram do_write_oneword(struct map_info *map, struct flchip *chip,
+ unsigned long adr, map_word datum,
+ int mode);
+
+static int do_otp_write(struct map_info *map, struct flchip *chip, loff_t adr,
+ size_t len, u_char *buf)
+{
+ int ret;
+ while (len) {
+ unsigned long bus_ofs = adr & ~(map_bankwidth(map)-1);
+ int gap = adr - bus_ofs;
+ int n = min_t(int, len, map_bankwidth(map) - gap);
+ map_word datum;
+
+ if (n != map_bankwidth(map)) {
+ /* partial write of a word, load old contents */
+ otp_enter(map, chip, bus_ofs, map_bankwidth(map));
+ datum = map_read(map, bus_ofs);
+ otp_exit(map, chip, bus_ofs, map_bankwidth(map));
+ }
+
+ datum = map_word_load_partial(map, datum, buf, gap, n);
+ ret = do_write_oneword(map, chip, bus_ofs, datum, FL_OTP_WRITE);
+ if (ret)
+ return ret;
+
+ adr += n;
+ buf += n;
+ len -= n;
+ }
+
+ return 0;
+}
+
static int cfi_amdstd_otp_walk(struct mtd_info *mtd, loff_t from, size_t len,
size_t *retlen, u_char *buf,
otp_op_t action, int user_regs)
@@ -1405,7 +1442,17 @@ static int cfi_amdstd_read_user_prot_reg(struct mtd_info *mtd, loff_t from,
buf, do_read_secsi_onechip, 1);
}
-static int __xipram do_write_oneword(struct map_info *map, struct flchip *chip, unsigned long adr, map_word datum)
+static int cfi_amdstd_write_user_prot_reg(struct mtd_info *mtd, loff_t from,
+ size_t len, size_t *retlen,
+ u_char *buf)
+{
+ return cfi_amdstd_otp_walk(mtd, from, len, retlen, buf,
+ do_otp_write, 1);
+}
+
+static int __xipram do_write_oneword(struct map_info *map, struct flchip *chip,
+ unsigned long adr, map_word datum,
+ int mode)
{
struct cfi_private *cfi = map->fldrv_priv;
unsigned long timeo = jiffies + HZ;
@@ -1426,7 +1473,7 @@ static int __xipram do_write_oneword(struct map_info *map, struct flchip *chip,
adr += chip->start;
mutex_lock(&chip->mutex);
- ret = get_chip(map, chip, adr, FL_WRITING);
+ ret = get_chip(map, chip, adr, mode);
if (ret) {
mutex_unlock(&chip->mutex);
return ret;
@@ -1435,6 +1482,9 @@ static int __xipram do_write_oneword(struct map_info *map, struct flchip *chip,
pr_debug("MTD %s(): WRITE 0x%.8lx(0x%.8lx)\n",
__func__, adr, datum.x[0] );
+ if (mode == FL_OTP_WRITE)
+ otp_enter(map, chip, adr, map_bankwidth(map));
+
/*
* Check for a NOP for the case when the datum to write is already
* present - it saves time and works around buggy chips that corrupt
@@ -1451,12 +1501,13 @@ static int __xipram do_write_oneword(struct map_info *map, struct flchip *chip,
XIP_INVAL_CACHED_RANGE(map, adr, map_bankwidth(map));
ENABLE_VPP(map);
xip_disable(map, chip, adr);
+
retry:
cfi_send_gen_cmd(0xAA, cfi->addr_unlock1, chip->start, map, cfi, cfi->device_type, NULL);
cfi_send_gen_cmd(0x55, cfi->addr_unlock2, chip->start, map, cfi, cfi->device_type, NULL);
cfi_send_gen_cmd(0xA0, cfi->addr_unlock1, chip->start, map, cfi, cfi->device_type, NULL);
map_write(map, datum, adr);
- chip->state = FL_WRITING;
+ chip->state = mode;
INVALIDATE_CACHE_UDELAY(map, chip,
adr, map_bankwidth(map),
@@ -1465,7 +1516,7 @@ static int __xipram do_write_oneword(struct map_info *map, struct flchip *chip,
/* See comment above for timeout value. */
timeo = jiffies + uWriteTimeout;
for (;;) {
- if (chip->state != FL_WRITING) {
+ if (chip->state != mode) {
/* Someone's suspended the write. Sleep */
DECLARE_WAITQUEUE(wait, current);
@@ -1505,6 +1556,8 @@ static int __xipram do_write_oneword(struct map_info *map, struct flchip *chip,
}
xip_enable(map, chip, adr);
op_done:
+ if (mode == FL_OTP_WRITE)
+ otp_exit(map, chip, adr, map_bankwidth(map));
chip->state = FL_READY;
DISABLE_VPP(map);
put_chip(map, chip, adr);
@@ -1560,7 +1613,7 @@ static int cfi_amdstd_write_words(struct mtd_info *mtd, loff_t to, size_t len,
tmp_buf = map_word_load_partial(map, tmp_buf, buf, i, n);
ret = do_write_oneword(map, &cfi->chips[chipnum],
- bus_ofs, tmp_buf);
+ bus_ofs, tmp_buf, FL_WRITING);
if (ret)
return ret;
@@ -1584,7 +1637,7 @@ static int cfi_amdstd_write_words(struct mtd_info *mtd, loff_t to, size_t len,
datum = map_word_load(map, buf);
ret = do_write_oneword(map, &cfi->chips[chipnum],
- ofs, datum);
+ ofs, datum, FL_WRITING);
if (ret)
return ret;
@@ -1627,7 +1680,7 @@ static int cfi_amdstd_write_words(struct mtd_info *mtd, loff_t to, size_t len,
tmp_buf = map_word_load_partial(map, tmp_buf, buf, 0, len);
ret = do_write_oneword(map, &cfi->chips[chipnum],
- ofs, tmp_buf);
+ ofs, tmp_buf, FL_WRITING);
if (ret)
return ret;
--
1.7.9.5
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