[PATCH v3] mtd: m25p80: Calculate flash block protect bits based on number of sectors
From: Austin Boyle
Date: Wed Apr 16 2014 - 08:37:48 EST
This patch generalises the calculation of block protect bits based on the number
of sectors and implements the _is_locked function.
Existing calculation of block protect bits only works for devices with 64
sectors or more. This new logic is applicable to the STmicro devices:
m25p10, p20, p40, p80, p16, pe16, p32, p64, p128.
Note devices with >64 sectors only allow the protected region to be specified
to a resolution of 1/64th of the total size (such as m25p64).
New return codes for ioctl(MEMISLOCKED) have been added to uapi/mtd/mtd-abi.h
because the _is_locked function can query a region which is partially unlocked.
Added flag to m25p_ids table to indicate if flash protection is supported.
Added n_sectors and sector_size to m25p flash structure so it can be used in
block protect bit calculation.
From: Austin Boyle <boyle.austin@xxxxxxxxx>
Signed-off-by: Austin Boyle <boyle.austin@xxxxxxxxx>
---
diff --git a/drivers/mtd/devices/m25p80.c b/drivers/mtd/devices/m25p80.c
index 524dab3..88240ae 100644
--- a/drivers/mtd/devices/m25p80.c
+++ b/drivers/mtd/devices/m25p80.c
@@ -78,8 +78,15 @@
#define SR_BP0 4 /* Block protect 0 */
#define SR_BP1 8 /* Block protect 1 */
#define SR_BP2 0x10 /* Block protect 2 */
+#define SR_BP_BIT_OFFSET 2 /* Offset to Block protect 0 */
+#define SR_BP_BIT_MASK (SR_BP2 | SR_BP1 | SR_BP0)
#define SR_SRWD 0x80 /* SR write protect */
+#define BP_BITS_FROM_SR(sr) (((sr) & SR_BP_BIT_MASK) >> SR_BP_BIT_OFFSET)
+
+/* Highest resolution of sector locking */
+#define M25P_MAX_LOCKABLE_SECTORS 64
+
#define SR_QUAD_EN_MX 0x40 /* Macronix Quad I/O */
/* Configuration Register bits. */
@@ -106,6 +113,8 @@ struct m25p {
struct mtd_info mtd;
u16 page_size;
u16 addr_width;
+ u16 n_sectors;
+ u32 sector_size;
u8 erase_opcode;
u8 read_opcode;
u8 program_opcode;
@@ -741,11 +750,46 @@ time_out:
return ret;
}
+static inline uint16_t min_lockable_sectors(uint16_t n_sectors)
+{
+ return max(1, n_sectors/M25P_MAX_LOCKABLE_SECTORS);
+}
+
+static inline uint32_t get_protected_area_start(struct m25p *flash,
+ uint8_t lock_bits)
+{
+ return flash->mtd.size - (1<<(lock_bits-1)) *
+ min_lockable_sectors(flash->n_sectors) * flash->sector_size;
+}
+
+static uint8_t min_protected_area_including_offset(struct m25p *flash,
+ uint32_t offset)
+{
+ uint8_t lock_bits;
+ for (lock_bits = 1; lock_bits < 7; lock_bits++) {
+ if (offset >= get_protected_area_start(flash, lock_bits))
+ break;
+ }
+ return lock_bits;
+}
+
+static int write_sr_modify_protection(struct m25p *flash, uint8_t status,
+ uint8_t lock_bits)
+{
+ uint8_t status_new = (status & ~SR_BP_BIT_MASK) |
+ ((lock_bits << SR_BP_BIT_OFFSET) & SR_BP_BIT_MASK);
+ write_enable(flash);
+ if (write_sr(flash, status_new) < 0)
+ return 1;
+ return 0;
+}
+
static int m25p80_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
{
struct m25p *flash = mtd_to_m25p(mtd);
uint32_t offset = ofs;
- uint8_t status_old, status_new;
+ uint8_t status;
+ uint8_t lock_bits;
int res = 0;
mutex_lock(&flash->lock);
@@ -754,33 +798,13 @@ static int m25p80_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
res = 1;
goto err;
}
+ status = read_sr(flash);
- status_old = read_sr(flash);
-
- if (offset < flash->mtd.size-(flash->mtd.size/2))
- status_new = status_old | SR_BP2 | SR_BP1 | SR_BP0;
- else if (offset < flash->mtd.size-(flash->mtd.size/4))
- status_new = (status_old & ~SR_BP0) | SR_BP2 | SR_BP1;
- else if (offset < flash->mtd.size-(flash->mtd.size/8))
- status_new = (status_old & ~SR_BP1) | SR_BP2 | SR_BP0;
- else if (offset < flash->mtd.size-(flash->mtd.size/16))
- status_new = (status_old & ~(SR_BP0|SR_BP1)) | SR_BP2;
- else if (offset < flash->mtd.size-(flash->mtd.size/32))
- status_new = (status_old & ~SR_BP2) | SR_BP1 | SR_BP0;
- else if (offset < flash->mtd.size-(flash->mtd.size/64))
- status_new = (status_old & ~(SR_BP2|SR_BP0)) | SR_BP1;
- else
- status_new = (status_old & ~(SR_BP2|SR_BP1)) | SR_BP0;
+ lock_bits = min_protected_area_including_offset(flash, offset);
/* Only modify protection if it will not unlock other areas */
- if ((status_new&(SR_BP2|SR_BP1|SR_BP0)) >
- (status_old&(SR_BP2|SR_BP1|SR_BP0))) {
- write_enable(flash);
- if (write_sr(flash, status_new) < 0) {
- res = 1;
- goto err;
- }
- }
+ if (lock_bits > BP_BITS_FROM_SR(status))
+ res = write_sr_modify_protection(flash, status, lock_bits);
err: mutex_unlock(&flash->lock);
return res;
@@ -790,7 +814,8 @@ static int m25p80_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
{
struct m25p *flash = mtd_to_m25p(mtd);
uint32_t offset = ofs;
- uint8_t status_old, status_new;
+ uint8_t status;
+ uint8_t lock_bits;
int res = 0;
mutex_lock(&flash->lock);
@@ -799,38 +824,47 @@ static int m25p80_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
res = 1;
goto err;
}
+ status = read_sr(flash);
- status_old = read_sr(flash);
-
- if (offset+len > flash->mtd.size-(flash->mtd.size/64))
- status_new = status_old & ~(SR_BP2|SR_BP1|SR_BP0);
- else if (offset+len > flash->mtd.size-(flash->mtd.size/32))
- status_new = (status_old & ~(SR_BP2|SR_BP1)) | SR_BP0;
- else if (offset+len > flash->mtd.size-(flash->mtd.size/16))
- status_new = (status_old & ~(SR_BP2|SR_BP0)) | SR_BP1;
- else if (offset+len > flash->mtd.size-(flash->mtd.size/8))
- status_new = (status_old & ~SR_BP2) | SR_BP1 | SR_BP0;
- else if (offset+len > flash->mtd.size-(flash->mtd.size/4))
- status_new = (status_old & ~(SR_BP0|SR_BP1)) | SR_BP2;
- else if (offset+len > flash->mtd.size-(flash->mtd.size/2))
- status_new = (status_old & ~SR_BP1) | SR_BP2 | SR_BP0;
- else
- status_new = (status_old & ~SR_BP0) | SR_BP2 | SR_BP1;
+ lock_bits = min_protected_area_including_offset(flash, offset+len) - 1;
/* Only modify protection if it will not lock other areas */
- if ((status_new&(SR_BP2|SR_BP1|SR_BP0)) <
- (status_old&(SR_BP2|SR_BP1|SR_BP0))) {
- write_enable(flash);
- if (write_sr(flash, status_new) < 0) {
- res = 1;
- goto err;
- }
- }
+ if (lock_bits < BP_BITS_FROM_SR(status))
+ res = write_sr_modify_protection(flash, status, lock_bits);
err: mutex_unlock(&flash->lock);
return res;
}
+static int m25p80_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
+{
+ struct m25p *flash = mtd_to_m25p(mtd);
+ uint32_t offset = ofs;
+ uint32_t protected_area_start;
+ uint8_t status;
+ int res;
+
+ mutex_lock(&flash->lock);
+ /* Wait until finished previous command */
+ if (wait_till_ready(flash)) {
+ mutex_unlock(&flash->lock);
+ return -EBUSY;
+ }
+ status = read_sr(flash);
+ mutex_unlock(&flash->lock);
+
+ protected_area_start = get_protected_area_start(flash,
+ BP_BITS_FROM_SR(status));
+ if (offset >= protected_area_start)
+ res = MTD_IS_LOCKED;
+ else if (offset+len < protected_area_start)
+ res = MTD_IS_UNLOCKED;
+ else
+ res = MTD_IS_PARTIALLY_LOCKED;
+
+ return res;
+}
+
/****************************************************************************/
/*
@@ -862,6 +896,7 @@ struct flash_info {
#define SECT_4K_PMC 0x10 /* OPCODE_BE_4K_PMC works uniformly */
#define M25P80_DUAL_READ 0x20 /* Flash supports Dual Read */
#define M25P80_QUAD_READ 0x40 /* Flash supports Quad Read */
+#define M25P_FLASH_LOCK 0x80 /* Flash protection support */
};
#define INFO(_jedec_id, _ext_id, _sector_size, _n_sectors, _flags) \
@@ -989,25 +1024,25 @@ static const struct spi_device_id m25p_ids[] = {
/* ST Microelectronics -- newer production may have feature updates */
{ "m25p05", INFO(0x202010, 0, 32 * 1024, 2, 0) },
- { "m25p10", INFO(0x202011, 0, 32 * 1024, 4, 0) },
- { "m25p20", INFO(0x202012, 0, 64 * 1024, 4, 0) },
- { "m25p40", INFO(0x202013, 0, 64 * 1024, 8, 0) },
- { "m25p80", INFO(0x202014, 0, 64 * 1024, 16, 0) },
- { "m25p16", INFO(0x202015, 0, 64 * 1024, 32, 0) },
- { "m25p32", INFO(0x202016, 0, 64 * 1024, 64, 0) },
- { "m25p64", INFO(0x202017, 0, 64 * 1024, 128, 0) },
- { "m25p128", INFO(0x202018, 0, 256 * 1024, 64, 0) },
+ { "m25p10", INFO(0x202011, 0, 32 * 1024, 4, M25P_FLASH_LOCK) },
+ { "m25p20", INFO(0x202012, 0, 64 * 1024, 4, M25P_FLASH_LOCK) },
+ { "m25p40", INFO(0x202013, 0, 64 * 1024, 8, M25P_FLASH_LOCK) },
+ { "m25p80", INFO(0x202014, 0, 64 * 1024, 16, M25P_FLASH_LOCK) },
+ { "m25p16", INFO(0x202015, 0, 64 * 1024, 32, M25P_FLASH_LOCK) },
+ { "m25p32", INFO(0x202016, 0, 64 * 1024, 64, M25P_FLASH_LOCK) },
+ { "m25p64", INFO(0x202017, 0, 64 * 1024, 128, M25P_FLASH_LOCK) },
+ { "m25p128", INFO(0x202018, 0, 256 * 1024, 64, M25P_FLASH_LOCK) },
{ "n25q032", INFO(0x20ba16, 0, 64 * 1024, 64, 0) },
{ "m25p05-nonjedec", INFO(0, 0, 32 * 1024, 2, 0) },
- { "m25p10-nonjedec", INFO(0, 0, 32 * 1024, 4, 0) },
- { "m25p20-nonjedec", INFO(0, 0, 64 * 1024, 4, 0) },
- { "m25p40-nonjedec", INFO(0, 0, 64 * 1024, 8, 0) },
- { "m25p80-nonjedec", INFO(0, 0, 64 * 1024, 16, 0) },
- { "m25p16-nonjedec", INFO(0, 0, 64 * 1024, 32, 0) },
- { "m25p32-nonjedec", INFO(0, 0, 64 * 1024, 64, 0) },
- { "m25p64-nonjedec", INFO(0, 0, 64 * 1024, 128, 0) },
- { "m25p128-nonjedec", INFO(0, 0, 256 * 1024, 64, 0) },
+ { "m25p10-nonjedec", INFO(0, 0, 32 * 1024, 4, M25P_FLASH_LOCK) },
+ { "m25p20-nonjedec", INFO(0, 0, 64 * 1024, 4, M25P_FLASH_LOCK) },
+ { "m25p40-nonjedec", INFO(0, 0, 64 * 1024, 8, M25P_FLASH_LOCK) },
+ { "m25p80-nonjedec", INFO(0, 0, 64 * 1024, 16, M25P_FLASH_LOCK) },
+ { "m25p16-nonjedec", INFO(0, 0, 64 * 1024, 32, M25P_FLASH_LOCK) },
+ { "m25p32-nonjedec", INFO(0, 0, 64 * 1024, 64, M25P_FLASH_LOCK) },
+ { "m25p64-nonjedec", INFO(0, 0, 64 * 1024, 128, M25P_FLASH_LOCK) },
+ { "m25p128-nonjedec", INFO(0, 0, 256 * 1024, 64, M25P_FLASH_LOCK) },
{ "m45pe10", INFO(0x204011, 0, 64 * 1024, 2, 0) },
{ "m45pe80", INFO(0x204014, 0, 64 * 1024, 16, 0) },
@@ -1015,7 +1050,7 @@ static const struct spi_device_id m25p_ids[] = {
{ "m25pe20", INFO(0x208012, 0, 64 * 1024, 4, 0) },
{ "m25pe80", INFO(0x208014, 0, 64 * 1024, 16, 0) },
- { "m25pe16", INFO(0x208015, 0, 64 * 1024, 32, SECT_4K) },
+ { "m25pe16", INFO(0x208015, 0, 64 * 1024, 32, SECT_4K | M25P_FLASH_LOCK) },
{ "m25px16", INFO(0x207115, 0, 64 * 1024, 32, SECT_4K) },
{ "m25px32", INFO(0x207116, 0, 64 * 1024, 64, SECT_4K) },
@@ -1183,13 +1218,17 @@ static int m25p_probe(struct spi_device *spi)
flash->mtd.writesize = 1;
flash->mtd.flags = MTD_CAP_NORFLASH;
flash->mtd.size = info->sector_size * info->n_sectors;
+ flash->n_sectors = info->n_sectors;
+ flash->sector_size = info->sector_size;
flash->mtd._erase = m25p80_erase;
flash->mtd._read = m25p80_read;
/* flash protection support for STmicro chips */
- if (JEDEC_MFR(info->jedec_id) == CFI_MFR_ST) {
+ if (JEDEC_MFR(info->jedec_id) == CFI_MFR_ST &&
+ (info->flags & M25P_FLASH_LOCK)) {
flash->mtd._lock = m25p80_lock;
flash->mtd._unlock = m25p80_unlock;
+ flash->mtd._is_locked = m25p80_is_locked;
}
/* sst flash chips use AAI word program */
diff --git a/include/uapi/mtd/mtd-abi.h b/include/uapi/mtd/mtd-abi.h
index e272ea0..f8f5e9d 100644
--- a/include/uapi/mtd/mtd-abi.h
+++ b/include/uapi/mtd/mtd-abi.h
@@ -251,7 +251,7 @@ struct mtd_ecc_stats {
__u32 bbtblocks;
};
-/*
+/**
* MTD file modes - for read/write access to MTD
*
* @MTD_FILE_MODE_NORMAL: OTP disabled, ECC enabled
@@ -275,6 +275,19 @@ enum mtd_file_modes {
MTD_FILE_MODE_RAW,
};
+/**
+ * MTD locking states - return codes for ioctl(MEMISLOCKED)
+ *
+ * @MTD_IS_UNLOCKED: Specified region is completely unlocked
+ * @MTD_IS_LOCKED: Specified region is completely locked
+ * @MTD_IS_PARTIALLY_LOCKED: Specified region is partially locked
+ */
+enum mtd_locking_states {
+ MTD_IS_UNLOCKED,
+ MTD_IS_LOCKED,
+ MTD_IS_PARTIALLY_LOCKED,
+};
+
static inline int mtd_type_is_nand_user(const struct mtd_info_user *mtd)
{
return mtd->type == MTD_NANDFLASH || mtd->type == MTD_MLCNANDFLASH;
--
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