[PATCH v2 1/4] mtd: cfi_cmdset_0002: Add support for reading OTP
Christian Riesch
christian.riesch at omicron.at
Fri Apr 26 15:10:27 EDT 2013
The Micron M29EW has a 256 byte one time programmable (OTP) memory.
This patch adds support for reading this memory. This support will be
extended for locking and writing in subsequent patches.
Signed-off-by: Christian Riesch <christian.riesch at omicron.at>
---
drivers/mtd/chips/cfi_cmdset_0002.c | 163 +++++++++++++++++++++++++++++++++++
1 file changed, 163 insertions(+)
diff --git a/drivers/mtd/chips/cfi_cmdset_0002.c b/drivers/mtd/chips/cfi_cmdset_0002.c
index fff665d..353ddfb 100644
--- a/drivers/mtd/chips/cfi_cmdset_0002.c
+++ b/drivers/mtd/chips/cfi_cmdset_0002.c
@@ -59,7 +59,15 @@ static void cfi_amdstd_sync (struct mtd_info *);
static int cfi_amdstd_suspend (struct mtd_info *);
static void cfi_amdstd_resume (struct mtd_info *);
static int cfi_amdstd_reboot(struct notifier_block *, unsigned long, void *);
+static int cfi_amdstd_get_fact_prot_info(struct mtd_info *, struct otp_info *,
+ size_t len);
+static int cfi_amdstd_get_user_prot_info(struct mtd_info *, struct otp_info *,
+ size_t len);
static int cfi_amdstd_secsi_read (struct mtd_info *, loff_t, size_t, size_t *, u_char *);
+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_panic_write(struct mtd_info *mtd, loff_t to, size_t len,
size_t *retlen, const u_char *buf);
@@ -521,6 +529,10 @@ struct mtd_info *cfi_cmdset_0002(struct map_info *map, int primary)
mtd->_sync = cfi_amdstd_sync;
mtd->_suspend = cfi_amdstd_suspend;
mtd->_resume = cfi_amdstd_resume;
+ mtd->_read_user_prot_reg = cfi_amdstd_read_user_prot_reg;
+ 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->flags = MTD_CAP_NORFLASH;
mtd->name = map->name;
mtd->writesize = 1;
@@ -1142,6 +1154,8 @@ static int cfi_amdstd_read (struct mtd_info *mtd, loff_t from, size_t len, size_
return ret;
}
+typedef int (*otp_op_t)(struct map_info *map, struct flchip *chip,
+ loff_t adr, size_t len, u_char *buf);
static inline int do_read_secsi_onechip(struct map_info *map, struct flchip *chip, loff_t adr, size_t len, u_char *buf)
{
@@ -1224,6 +1238,155 @@ static int cfi_amdstd_secsi_read (struct mtd_info *mtd, loff_t from, size_t len,
return ret;
}
+static int __xipram 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)
+{
+ struct map_info *map = mtd->priv;
+ struct cfi_private *cfi = map->fldrv_priv;
+ int ofs_factor = cfi->interleave * cfi->device_type;
+ unsigned long base;
+ int chipnum;
+ struct flchip *chip;
+ uint8_t otp, lockreg;
+ int ret;
+
+ size_t user_size, factory_size, otpsize;
+ loff_t user_offset, factory_offset, otpoffset;
+ int user_locked = 0, otplocked;
+
+ *retlen = 0;
+
+ for (chipnum = 0; chipnum < cfi->numchips; chipnum++) {
+ chip = &cfi->chips[chipnum];
+ factory_size = 0;
+ user_size = 0;
+
+ /* Micron M29EW family */
+ if (is_m29ew(cfi)) {
+ base = chip->start;
+
+ /* check whether secsi area is factory locked
+ or user lockable */
+ mutex_lock(&chip->mutex);
+ ret = get_chip(map, chip, base, FL_CFI_QUERY);
+ if (ret) {
+ mutex_unlock(&chip->mutex);
+ return ret;
+ }
+ cfi_qry_mode_on(base, map, cfi);
+ otp = cfi_read_query(map, base + 0x3 * ofs_factor);
+ cfi_qry_mode_off(base, map, cfi);
+ put_chip(map, chip, base);
+ mutex_unlock(&chip->mutex);
+
+ if (otp & 0x80) {
+ /* factory locked */
+ factory_offset = 0;
+ factory_size = 0x100;
+ } else {
+ /* customer lockable */
+ user_offset = 0;
+ user_size = 0x100;
+
+ mutex_lock(&chip->mutex);
+ ret = get_chip(map, chip, base, FL_LOCKING);
+
+ /* Enter lock register command */
+ 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(0x40, cfi->addr_unlock1,
+ chip->start, map, cfi,
+ cfi->device_type, NULL);
+ /* read lock register */
+ lockreg = cfi_read_query(map, 0);
+ /* exit protection commands */
+ map_write(map, CMD(0x90), chip->start);
+ map_write(map, CMD(0x00), chip->start);
+ put_chip(map, chip, chip->start);
+ mutex_unlock(&chip->mutex);
+
+ user_locked = ((lockreg & 0x01) == 0x00);
+ }
+ }
+
+ otpsize = user_regs ? user_size : factory_size;
+ if (!otpsize)
+ continue;
+ otpoffset = user_regs ? user_offset : factory_offset;
+ otplocked = user_regs ? user_locked : 1;
+
+ if (!action) {
+ /* return otpinfo */
+ struct otp_info *otpinfo;
+ len -= sizeof(*otpinfo);
+ if (len <= 0)
+ return -ENOSPC;
+ otpinfo = (struct otp_info *)buf;
+ otpinfo->start = from;
+ otpinfo->length = otpsize;
+ otpinfo->locked = otplocked;
+ buf += sizeof(*otpinfo);
+ *retlen += sizeof(*otpinfo);
+ from += otpsize;
+ } else if ((from < otpsize) && (len > 0)) {
+ size_t size;
+ size = (len < otpsize - from) ? len : otpsize - from;
+ ret = action(map, chip, otpoffset + from, size, buf);
+ if (ret < 0)
+ return ret;
+
+ buf += size;
+ len -= size;
+ *retlen += size;
+ from = 0;
+ } else {
+ from -= otpsize;
+ }
+ }
+ return 0;
+}
+
+static int cfi_amdstd_get_fact_prot_info(struct mtd_info *mtd,
+ struct otp_info *buf, size_t len)
+{
+ size_t retlen;
+ int ret;
+
+ ret = cfi_amdstd_otp_walk(mtd, 0, len, &retlen, (u_char *)buf, NULL, 0);
+ return ret ? : retlen;
+}
+
+static int cfi_amdstd_get_user_prot_info(struct mtd_info *mtd,
+ struct otp_info *buf, size_t len)
+{
+ size_t retlen;
+ int ret;
+
+ ret = cfi_amdstd_otp_walk(mtd, 0, len, &retlen, (u_char *)buf, NULL, 1);
+ return ret ? : retlen;
+}
+
+static int cfi_amdstd_read_fact_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_read_secsi_onechip, 0);
+}
+
+static int cfi_amdstd_read_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_read_secsi_onechip, 1);
+}
static int __xipram do_write_oneword(struct map_info *map, struct flchip *chip, unsigned long adr, map_word datum)
{
--
1.7.9.5
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