[PATCH v3 1/3] mtd: spi-nor: Parse BFPT to determine the 4-Byte Address Mode methods

From: Tudor Ambarus
Date: Mon Apr 11 2022 - 08:54:02 EST


BFPT[DWORD(16)] defines the methods to enter and exit the 4-Byte Address
Mode. Parse BFPT to determine the method. Will rename the methods with
generic names in a further patch, to keep things trackable in this one.

Some regressions may be introduced by this patch, because the
params->set_4byte_addr_mode method that was set either in
spi_nor_init_default_params() or later overwritten in default_init() hooks,
may now be overwritten with a different value based on the BFPT data. If
that's the case, the fix is to introduce a post_bfpt fixup hook where one
should fix the wrong BFPT info.

Signed-off-by: Tudor Ambarus <tudor.ambarus@xxxxxxxxxxxxx>
Reviewed-by: Pratyush Yadav <p.yadav@xxxxxx>
---
v3: move BFPT definitions in sfdp.h as they may be used by manufacturer
drivers to handle flash ID collisions.

drivers/mtd/spi-nor/core.c | 63 -------------------
drivers/mtd/spi-nor/core.h | 1 -
drivers/mtd/spi-nor/micron-st.c | 24 --------
drivers/mtd/spi-nor/sfdp.c | 105 ++++++++++++++++++++++++++++++++
drivers/mtd/spi-nor/sfdp.h | 29 +++++++++
drivers/mtd/spi-nor/winbond.c | 16 +++--
6 files changed, 144 insertions(+), 94 deletions(-)

diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c
index fe853532204c..2b26a8cef0c3 100644
--- a/drivers/mtd/spi-nor/core.c
+++ b/drivers/mtd/spi-nor/core.c
@@ -502,69 +502,6 @@ int spi_nor_read_cr(struct spi_nor *nor, u8 *cr)
return ret;
}

-/**
- * spi_nor_set_4byte_addr_mode() - Enter/Exit 4-byte address mode.
- * @nor: pointer to 'struct spi_nor'.
- * @enable: true to enter the 4-byte address mode, false to exit the 4-byte
- * address mode.
- *
- * Return: 0 on success, -errno otherwise.
- */
-int spi_nor_set_4byte_addr_mode(struct spi_nor *nor, bool enable)
-{
- int ret;
-
- if (nor->spimem) {
- struct spi_mem_op op = SPI_NOR_EN4B_EX4B_OP(enable);
-
- spi_nor_spimem_setup_op(nor, &op, nor->reg_proto);
-
- ret = spi_mem_exec_op(nor->spimem, &op);
- } else {
- ret = spi_nor_controller_ops_write_reg(nor,
- enable ? SPINOR_OP_EN4B :
- SPINOR_OP_EX4B,
- NULL, 0);
- }
-
- if (ret)
- dev_dbg(nor->dev, "error %d setting 4-byte mode\n", ret);
-
- return ret;
-}
-
-/**
- * spansion_set_4byte_addr_mode() - Set 4-byte address mode for Spansion
- * flashes.
- * @nor: pointer to 'struct spi_nor'.
- * @enable: true to enter the 4-byte address mode, false to exit the 4-byte
- * address mode.
- *
- * Return: 0 on success, -errno otherwise.
- */
-static int spansion_set_4byte_addr_mode(struct spi_nor *nor, bool enable)
-{
- int ret;
-
- nor->bouncebuf[0] = enable << 7;
-
- if (nor->spimem) {
- struct spi_mem_op op = SPI_NOR_BRWR_OP(nor->bouncebuf);
-
- spi_nor_spimem_setup_op(nor, &op, nor->reg_proto);
-
- ret = spi_mem_exec_op(nor->spimem, &op);
- } else {
- ret = spi_nor_controller_ops_write_reg(nor, SPINOR_OP_BRWR,
- nor->bouncebuf, 1);
- }
-
- if (ret)
- dev_dbg(nor->dev, "error %d setting 4-byte mode\n", ret);
-
- return ret;
-}
-
/**
* spi_nor_write_ear() - Write Extended Address Register.
* @nor: pointer to 'struct spi_nor'.
diff --git a/drivers/mtd/spi-nor/core.h b/drivers/mtd/spi-nor/core.h
index 8b7e597fd38c..c83d5e75c563 100644
--- a/drivers/mtd/spi-nor/core.h
+++ b/drivers/mtd/spi-nor/core.h
@@ -634,7 +634,6 @@ void spi_nor_spimem_setup_op(const struct spi_nor *nor,
const enum spi_nor_protocol proto);
int spi_nor_write_enable(struct spi_nor *nor);
int spi_nor_write_disable(struct spi_nor *nor);
-int spi_nor_set_4byte_addr_mode(struct spi_nor *nor, bool enable);
int spi_nor_write_ear(struct spi_nor *nor, u8 ear);
int spi_nor_wait_till_ready(struct spi_nor *nor);
int spi_nor_global_block_unlock(struct spi_nor *nor);
diff --git a/drivers/mtd/spi-nor/micron-st.c b/drivers/mtd/spi-nor/micron-st.c
index 26b9a1c2309d..d2903c5b5b87 100644
--- a/drivers/mtd/spi-nor/micron-st.c
+++ b/drivers/mtd/spi-nor/micron-st.c
@@ -298,30 +298,6 @@ static const struct flash_info st_nor_parts[] = {
{ "m25px80", INFO(0x207114, 0, 64 * 1024, 16) },
};

-/**
- * micron_st_nor_set_4byte_addr_mode() - Set 4-byte address mode for ST and
- * Micron flashes.
- * @nor: pointer to 'struct spi_nor'.
- * @enable: true to enter the 4-byte address mode, false to exit the 4-byte
- * address mode.
- *
- * Return: 0 on success, -errno otherwise.
- */
-static int micron_st_nor_set_4byte_addr_mode(struct spi_nor *nor, bool enable)
-{
- int ret;
-
- ret = spi_nor_write_enable(nor);
- if (ret)
- return ret;
-
- ret = spi_nor_set_4byte_addr_mode(nor, enable);
- if (ret)
- return ret;
-
- return spi_nor_write_disable(nor);
-}
-
/**
* micron_st_nor_read_fsr() - Read the Flag Status Register.
* @nor: pointer to 'struct spi_nor'
diff --git a/drivers/mtd/spi-nor/sfdp.c b/drivers/mtd/spi-nor/sfdp.c
index a5211543d30d..2e40eba3744d 100644
--- a/drivers/mtd/spi-nor/sfdp.c
+++ b/drivers/mtd/spi-nor/sfdp.c
@@ -401,6 +401,93 @@ static void spi_nor_regions_sort_erase_types(struct spi_nor_erase_map *map)
}
}

+/**
+ * spansion_set_4byte_addr_mode() - Set 4-byte address mode for Spansion
+ * flashes.
+ * @nor: pointer to 'struct spi_nor'.
+ * @enable: true to enter the 4-byte address mode, false to exit the 4-byte
+ * address mode.
+ *
+ * Return: 0 on success, -errno otherwise.
+ */
+int spansion_set_4byte_addr_mode(struct spi_nor *nor, bool enable)
+{
+ int ret;
+
+ nor->bouncebuf[0] = enable << 7;
+
+ if (nor->spimem) {
+ struct spi_mem_op op = SPI_NOR_BRWR_OP(nor->bouncebuf);
+
+ spi_nor_spimem_setup_op(nor, &op, nor->reg_proto);
+
+ ret = spi_mem_exec_op(nor->spimem, &op);
+ } else {
+ ret = spi_nor_controller_ops_write_reg(nor, SPINOR_OP_BRWR,
+ nor->bouncebuf, 1);
+ }
+
+ if (ret)
+ dev_dbg(nor->dev, "error %d setting 4-byte mode\n", ret);
+
+ return ret;
+}
+
+/**
+ * spi_nor_set_4byte_addr_mode() - Enter/Exit 4-byte address mode.
+ * @nor: pointer to 'struct spi_nor'.
+ * @enable: true to enter the 4-byte address mode, false to exit the 4-byte
+ * address mode.
+ *
+ * Return: 0 on success, -errno otherwise.
+ */
+int spi_nor_set_4byte_addr_mode(struct spi_nor *nor, bool enable)
+{
+ int ret;
+
+ if (nor->spimem) {
+ struct spi_mem_op op = SPI_NOR_EN4B_EX4B_OP(enable);
+
+ spi_nor_spimem_setup_op(nor, &op, nor->reg_proto);
+
+ ret = spi_mem_exec_op(nor->spimem, &op);
+ } else {
+ ret = spi_nor_controller_ops_write_reg(nor,
+ enable ? SPINOR_OP_EN4B :
+ SPINOR_OP_EX4B,
+ NULL, 0);
+ }
+
+ if (ret)
+ dev_dbg(nor->dev, "error %d setting 4-byte mode\n", ret);
+
+ return ret;
+}
+
+/**
+ * micron_st_nor_set_4byte_addr_mode() - Set 4-byte address mode for ST and
+ * Micron flashes.
+ * @nor: pointer to 'struct spi_nor'.
+ * @enable: true to enter the 4-byte address mode, false to exit the 4-byte
+ * address mode.
+ *
+ * Return: 0 on success, -errno otherwise.
+ */
+int micron_st_nor_set_4byte_addr_mode(struct spi_nor *nor, bool enable)
+{
+ int ret;
+
+ ret = spi_nor_write_enable(nor);
+ if (ret)
+ return ret;
+
+ ret = spi_nor_set_4byte_addr_mode(nor, enable);
+ if (ret)
+ return ret;
+
+ return spi_nor_write_disable(nor);
+}
+
/**
* spi_nor_parse_bfpt() - read and parse the Basic Flash Parameter Table.
* @nor: pointer to a 'struct spi_nor'
@@ -606,6 +693,24 @@ static int spi_nor_parse_bfpt(struct spi_nor *nor,
break;
}

+ switch (bfpt.dwords[BFPT_DWORD(16)] & BFPT_DWORD16_4B_ADDR_MODE_MASK) {
+ case BFPT_DWORD16_4B_ADDR_MODE_BRWR:
+ params->set_4byte_addr_mode = spansion_set_4byte_addr_mode;
+ break;
+
+ case BFPT_DWORD16_4B_ADDR_MODE_WREN_EN4B_EX4B:
+ params->set_4byte_addr_mode = micron_st_nor_set_4byte_addr_mode;
+ break;
+
+ case BFPT_DWORD16_4B_ADDR_MODE_EN4B_EX4B:
+ params->set_4byte_addr_mode = spi_nor_set_4byte_addr_mode;
+ break;
+
+ default:
+ dev_dbg(nor->dev, "BFPT: 4-Byte Address Mode method is not recognized or not implemented\n");
+ break;
+ }
+
/* Soft Reset support. */
if (bfpt.dwords[BFPT_DWORD(16)] & BFPT_DWORD16_SWRST_EN_RST)
nor->flags |= SNOR_F_SOFT_RESET;
diff --git a/drivers/mtd/spi-nor/sfdp.h b/drivers/mtd/spi-nor/sfdp.h
index bbf80d2990ab..3a3744da78ba 100644
--- a/drivers/mtd/spi-nor/sfdp.h
+++ b/drivers/mtd/spi-nor/sfdp.h
@@ -90,6 +90,32 @@ struct sfdp_bfpt {
#define BFPT_DWORD15_QER_SR2_BIT1_NO_RD (0x4UL << 20)
#define BFPT_DWORD15_QER_SR2_BIT1 (0x5UL << 20) /* Spansion */

+#define BFPT_DWORD16_EN4B_MASK GENMASK(31, 24)
+#define BFPT_DWORD16_EN4B_ALWAYS_4B BIT(30)
+#define BFPT_DWORD16_EN4B_4B_OPCODES BIT(29)
+#define BFPT_DWORD16_EN4B_16BIT_NV_CR BIT(28)
+#define BFPT_DWORD16_EN4B_BRWR BIT(27)
+#define BFPT_DWORD16_EN4B_WREAR BIT(26)
+#define BFPT_DWORD16_EN4B_WREN_EN4B BIT(25)
+#define BFPT_DWORD16_EN4B_EN4B BIT(24)
+#define BFPT_DWORD16_EX4B_MASK GENMASK(18, 14)
+#define BFPT_DWORD16_EX4B_16BIT_NV_CR BIT(18)
+#define BFPT_DWORD16_EX4B_BRWR BIT(17)
+#define BFPT_DWORD16_EX4B_WREAR BIT(16)
+#define BFPT_DWORD16_EX4B_WREN_EX4B BIT(15)
+#define BFPT_DWORD16_EX4B_EX4B BIT(14)
+#define BFPT_DWORD16_4B_ADDR_MODE_MASK \
+ (BFPT_DWORD16_EN4B_MASK | BFPT_DWORD16_EX4B_MASK)
+#define BFPT_DWORD16_4B_ADDR_MODE_16BIT_NV_CR \
+ (BFPT_DWORD16_EN4B_16BIT_NV_CR | BFPT_DWORD16_EX4B_16BIT_NV_CR)
+#define BFPT_DWORD16_4B_ADDR_MODE_BRWR \
+ (BFPT_DWORD16_EN4B_BRWR | BFPT_DWORD16_EX4B_BRWR)
+#define BFPT_DWORD16_4B_ADDR_MODE_WREAR \
+ (BFPT_DWORD16_EN4B_WREAR | BFPT_DWORD16_EX4B_WREAR)
+#define BFPT_DWORD16_4B_ADDR_MODE_WREN_EN4B_EX4B \
+ (BFPT_DWORD16_EN4B_WREN_EN4B | BFPT_DWORD16_EX4B_WREN_EX4B)
+#define BFPT_DWORD16_4B_ADDR_MODE_EN4B_EX4B \
+ (BFPT_DWORD16_EN4B_EN4B | BFPT_DWORD16_EX4B_EX4B)
#define BFPT_DWORD16_SWRST_EN_RST BIT(12)

#define BFPT_DWORD18_CMD_EXT_MASK GENMASK(30, 29)
@@ -107,6 +133,9 @@ struct sfdp_parameter_header {
u8 id_msb;
};

+int spansion_set_4byte_addr_mode(struct spi_nor *nor, bool enable);
+int spi_nor_set_4byte_addr_mode(struct spi_nor *nor, bool enable);
+int micron_st_nor_set_4byte_addr_mode(struct spi_nor *nor, bool enable);
int spi_nor_parse_sfdp(struct spi_nor *nor);

#endif /* __LINUX_MTD_SFDP_H */
diff --git a/drivers/mtd/spi-nor/winbond.c b/drivers/mtd/spi-nor/winbond.c
index fe80dffc2e70..374ba82bff49 100644
--- a/drivers/mtd/spi-nor/winbond.c
+++ b/drivers/mtd/spi-nor/winbond.c
@@ -170,19 +170,23 @@ static const struct spi_nor_otp_ops winbond_nor_otp_ops = {
.is_locked = spi_nor_otp_is_locked_sr2,
};

-static void winbond_nor_default_init(struct spi_nor *nor)
-{
- nor->params->set_4byte_addr_mode = winbond_nor_set_4byte_addr_mode;
-}
-
static void winbond_nor_late_init(struct spi_nor *nor)
{
if (nor->params->otp.org->n_regions)
nor->params->otp.ops = &winbond_nor_otp_ops;
+
+ /*
+ * Winbond seems to require that the Extended Address Register to be set
+ * to zero when exiting the 4-Byte Address Mode, at least for W25Q256FV.
+ * This requirement is not described in the JESD216 SFDP standard, thus
+ * it is Winbond specific. Since we do not know if other Winbond flashes
+ * have the same requirement, play safe and overwrite the method parsed
+ * from BFPT, if any.
+ */
+ nor->params->set_4byte_addr_mode = winbond_nor_set_4byte_addr_mode;
}

static const struct spi_nor_fixups winbond_nor_fixups = {
- .default_init = winbond_nor_default_init,
.late_init = winbond_nor_late_init,
};

--
2.25.1