This table is indication that the flash is xSPI compliant and hence
supports octal DTR mode. Extract information like the fast read opcode,
the number of dummy cycles needed for a Read Status Register command,
and the number of address bytes needed for a Read Status Register
command.
The default dummy cycles for a fast octal DTR read are set to 20. Since
there is no simple way of determining the dummy cycles needed for the
fast read command, flashes that use a different value should update it
in their flash-specific hooks.
Signed-off-by: Pratyush Yadav <p.yadav@xxxxxx>
---
drivers/mtd/spi-nor/spi-nor.c | 80 +++++++++++++++++++++++++++++++++++
include/linux/mtd/spi-nor.h | 5 +++
2 files changed, 85 insertions(+)
diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
index c86c1537f76e..22784c403d77 100644
--- a/drivers/mtd/spi-nor/spi-nor.c
+++ b/drivers/mtd/spi-nor/spi-nor.c
@@ -16,6 +16,7 @@
#include <linux/sizes.h>
#include <linux/slab.h>
#include <linux/sort.h>
+#include <linux/bitfield.h>
#include <linux/mtd/mtd.h>
#include <linux/of_platform.h>
@@ -58,12 +59,14 @@ struct sfdp_parameter_header {
#define SFDP_BFPT_ID 0xff00 /* Basic Flash Parameter Table */
#define SFDP_SECTOR_MAP_ID 0xff81 /* Sector Map Table */
#define SFDP_4BAIT_ID 0xff84 /* 4-byte Address Instruction Table */
+#define SFDP_PROFILE1_ID 0xff05 /* xSPI Profile 1.0 table. */
#define SFDP_SIGNATURE 0x50444653U
#define SFDP_JESD216_MAJOR 1
#define SFDP_JESD216_MINOR 0
#define SFDP_JESD216A_MINOR 5
#define SFDP_JESD216B_MINOR 6
+#define SFDP_JESD216D_MINOR 8
struct sfdp_header {
u32 signature; /* Ox50444653U <=> "SFDP" */
@@ -158,6 +161,11 @@ struct sfdp_bfpt {
u32 dwords[BFPT_DWORD_MAX];
};
+/* xSPI Profile 1.0 table (from JESD216D.01). */
+#define PROFILE1_DWORD1_RD_FAST_CMD GENMASK(15, 8)
+#define PROFILE1_DWORD1_RDSR_DUMMY BIT(28)
+#define PROFILE1_DWORD1_RDSR_ADDR_BYTES BIT(29)
+
/**
* struct spi_nor_fixups - SPI NOR fixup hooks
* @default_init: called after default flash parameters init. Used to tweak
@@ -4426,6 +4434,74 @@ static int spi_nor_parse_4bait(struct spi_nor *nor,
return ret;
}
+/**
+ * spi_nor_parse_profile1() - parse the xSPI Profile 1.0 table
+ * @nor: pointer to a 'struct spi_nor'
+ * @param_header: pointer to the 'struct sfdp_parameter_header' describing
+ * the 4-Byte Address Instruction Table length and version.
+ * @params: pointer to the 'struct spi_nor_flash_parameter' to be.
+ *
+ * Return: 0 on success, -errno otherwise.
+ */
+static int spi_nor_parse_profile1(struct spi_nor *nor,
+ const struct sfdp_parameter_header *profile1_header,
+ struct spi_nor_flash_parameter *params)
+{
+ u32 *table, opcode, addr;
+ size_t len;
+ int ret, i;
+
+ len = profile1_header->length * sizeof(*table);
+ table = kmalloc(len, GFP_KERNEL);
+ if (!table)
+ return -ENOMEM;
+
+ addr = SFDP_PARAM_HEADER_PTP(profile1_header);
+ ret = spi_nor_read_sfdp(nor, addr, len, table);
+ if (ret)
+ goto out;
+
+ /* Fix endianness of the table DWORDs. */
+ for (i = 0; i < profile1_header->length; i++)
+ table[i] = le32_to_cpu(table[i]);
+
+ /* Get 8D-8D-8D fast read opcode and dummy cycles. */
+ opcode = FIELD_GET(PROFILE1_DWORD1_RD_FAST_CMD, table[0]);
+
+ /*
+ * Update the fast read settings. We set the default dummy cycles to 20
+ * here. Flashes can change this value if they need to when enabling
+ * octal mode.
+ */
+ params->hwcaps.mask |= SNOR_HWCAPS_READ_8_8_8_DTR;
+ spi_nor_set_read_settings(¶ms->reads[SNOR_CMD_READ_8_8_8_DTR],
+ 0, 20, opcode,
+ SNOR_PROTO_8_8_8_DTR);
+
+ /*
+ * Since the flash supports xSPI DTR reads, it should also support DTR
+ * Page Program opcodes.
+ */
+ params->hwcaps.mask |= SNOR_HWCAPS_PP_8_8_8_DTR;
+
+ /*
+ * Set the Read Status Register dummy cycles and dummy address bytes.
+ */
+ if (table[0] & PROFILE1_DWORD1_RDSR_DUMMY)
+ params->rdsr_dummy = 8;
+ else
+ params->rdsr_dummy = 4;
+
+ if (table[0] & PROFILE1_DWORD1_RDSR_ADDR_BYTES)
+ params->rdsr_addr_nbytes = 4;
+ else
+ params->rdsr_addr_nbytes = 0;
+
+out:
+ kfree(table);
+ return ret;
+}
+
/**
* spi_nor_parse_sfdp() - parse the Serial Flash Discoverable Parameters.
* @nor: pointer to a 'struct spi_nor'
@@ -4527,6 +4603,10 @@ static int spi_nor_parse_sfdp(struct spi_nor *nor,
err = spi_nor_parse_4bait(nor, param_header, params);
break;
+ case SFDP_PROFILE1_ID:
+ err = spi_nor_parse_profile1(nor, param_header, params);
+ break;
+
default:
break;
}
diff --git a/include/linux/mtd/spi-nor.h b/include/linux/mtd/spi-nor.h
index 364f37276d78..f54dbd0f86ab 100644
--- a/include/linux/mtd/spi-nor.h
+++ b/include/linux/mtd/spi-nor.h
@@ -515,6 +515,9 @@ struct spi_nor_locking_ops {
*
* @size: the flash memory density in bytes.
* @page_size: the page size of the SPI NOR flash memory.
+ * @rdsr_dummy: dummy cycles needed for Read Status Register command.
+ * @rdsr_addr_nbytes: dummy address bytes needed for Read Status Register
+ * command.
* @hwcaps: describes the read and page program hardware
* capabilities.
* @reads: read capabilities ordered by priority: the higher index
@@ -537,6 +540,8 @@ struct spi_nor_locking_ops {
struct spi_nor_flash_parameter {
u64 size;
u32 page_size;
+ u8 rdsr_dummy;
+ u8 rdsr_addr_nbytes;
struct spi_nor_hwcaps hwcaps;
struct spi_nor_read_command reads[SNOR_CMD_READ_MAX];
--
2.25.0
