[PATCH v2 2/5] mtd: spi-nor: sfdp: Add support for xSPI profile 1.0 table

Mason Yang
2020-04-21T07:08:49Z

xSPI(eXpanded Serial Peripheral Interface) is for Non Volatile Memory
Devices supports Octal DTR mode.

Extract information like:
Read Fast command, the number of dummy cycles and address bytes
for Read Status Register command.

Read/Write volatile Register command for Configuration(CFG) Register 2.

The dummy cycless used for various frequencies.

Signed-off-by: Mason Yang <masonccyang@mxic.com.tw>
---
drivers/mtd/spi-nor/core.h | 14 ++++++
drivers/mtd/spi-nor/sfdp.c | 106 ++++++++++++++++++++++++++++++++++++++++++++-
2 files changed, 119 insertions(+), 1 deletion(-)

diff --git a/drivers/mtd/spi-nor/core.h b/drivers/mtd/spi-nor/core.h
index 6f2f6b2..2ea11fa 100644
--- a/drivers/mtd/spi-nor/core.h
+++ b/drivers/mtd/spi-nor/core.h
@@ -208,6 +208,12 @@ struct spi_nor_locking_ops {
* e.g. different opcodes, specific address calculation,
* page size, etc.
* @locking_ops: SPI NOR locking methods.
+ * @dtr_read_cmd: xSPI Octal DTR Read Fast command.
+ * @rdsr_addr_nbytes: xSPI Octal address bytes for read status register.
+ * @rdsr_dummy_cycles: xSPI Octal dummy cycles for read status register.
+ * @rd_reg_cmd: xSPI Octal read volatile register command.
+ * @wr_reg_cmd: xSPI Octal write volatile register command.
+ * @dummy_cycles: xSPI Octal dummy cycles used for various frequencies.
*/
struct spi_nor_flash_parameter {
u64 size;
@@ -225,6 +231,14 @@ struct spi_nor_flash_parameter {
int (*setup)(struct spi_nor *nor, const struct spi_nor_hwcaps *hwcaps);

const struct spi_nor_locking_ops *locking_ops;
+
+ /* xSPI profile 1.0 parameter for Octal 8S-8S-8S/8D-8D-8D */
+ u8 dtr_read_cmd;
+ u8 rdsr_addr_nbytes;
+ u8 rdsr_dummy_cycles;
+ u8 rd_reg_cmd;
+ u8 wr_reg_cmd;
+ u8 dummy_cycles;
};

/**
diff --git a/drivers/mtd/spi-nor/sfdp.c b/drivers/mtd/spi-nor/sfdp.c
index f6038d3..26814a1 100644
--- a/drivers/mtd/spi-nor/sfdp.c
+++ b/drivers/mtd/spi-nor/sfdp.c
@@ -7,6 +7,7 @@
#include <linux/slab.h>
#include <linux/sort.h>
#include <linux/mtd/spi-nor.h>
+#include <linux/bitfield.h>

#include "core.h"

@@ -19,6 +20,7 @@
#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_XSPI_PF1_ID 0xff05 /* xSPI Profile 1.0 table. */

#define SFDP_SIGNATURE 0x50444653U
#define SFDP_JESD216_MAJOR 1
@@ -26,6 +28,28 @@
#define SFDP_JESD216A_MINOR 5
#define SFDP_JESD216B_MINOR 6

+/* xSPI Profile 1.0 table (from JESD216D.01). */
+#define XSPI_PF1_DWORD1_RD_CMD GENMASK(15, 8)
+#define XSPI_PF1_DWORD1_RDSR_ADDR_BYTES BIT(29)
+#define XSPI_PF1_DWORD1_RDSR_DUMMY_CYCLES BIT(28)
+
+#define XSPI_PF1_DWORD2_RD_REG_CMD GENMASK(31, 24)
+#define XSPI_PF1_DWORD2_WR_REG_CMD GENMASK(15, 8)
+
+#define XSPI_DWORD(x) ((x) - 1)
+#define XSPI_DWORD_MAX 5
+
+struct sfdp_xspi {
+ u32 dwords[XSPI_DWORD_MAX];
+};
+
+struct xspi_dummy_cycles {
+ u16 speed_hz; /* Speed MHz */
+ u8 dwords; /* Dwords index */
+ u32 mask; /* Mask */
+ u8 shift; /* Bit shift */
+};
+
struct sfdp_header {
u32 signature; /* Ox50444653U <=> "SFDP" */
u8 minor;
@@ -1081,6 +1105,83 @@ static int spi_nor_parse_4bait(struct spi_nor *nor,
}

/**
+ * spi_nor_parse_xspi_pf1() - 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_xspi_pf1(struct spi_nor *nor,
+ const struct sfdp_parameter_header *header,
+ struct spi_nor_flash_parameter *params)
+{
+ struct sfdp_xspi pfile1;
+ u32 i, addr;
+ size_t len;
+ int ret;
+ static const struct xspi_dummy_cycles dummy[] = {
+ /* {MHz, Dwords index, Mask, Bit shift} */
+ { 200, 4, GENMASK(11, 7), 7},
+ { 166, 5, GENMASK(31, 27), 27},
+ { 133, 5, GENMASK(21, 17), 17},
+ { 100, 5, GENMASK(11, 7), 7},
+ };
+
+ if (header->major != SFDP_JESD216_MAJOR ||
+ header->length < XSPI_DWORD_MAX)
+ return -EINVAL;
+
+ len = min_t(size_t, sizeof(pfile1),
+ header->length * sizeof(u32));
+
+ memset(&pfile1, 0, sizeof(pfile1));
+
+ addr = SFDP_PARAM_HEADER_PTP(header);
+ ret = spi_nor_read_sfdp(nor, addr, len, &pfile1);
+ if (ret)
+ goto out;
+
+ /* Fix endianness of the xSPI 1.0 DWORDs. */
+ le32_to_cpu_array(pfile1.dwords, XSPI_DWORD_MAX);
+
+ /* Get 8D-8D-8D fast read opcode and dummy cycles. */
+ params->dtr_read_cmd = FIELD_GET(XSPI_PF1_DWORD1_RD_CMD,
+ pfile1.dwords[XSPI_DWORD(1)]);
+
+ if (pfile1.dwords[XSPI_DWORD(1)] & XSPI_PF1_DWORD1_RDSR_ADDR_BYTES)
+ params->rdsr_addr_nbytes = 4;
+ else
+ params->rdsr_addr_nbytes = 0;
+
+ if (pfile1.dwords[XSPI_DWORD(1)] & XSPI_PF1_DWORD1_RDSR_DUMMY_CYCLES)
+ params->rdsr_dummy_cycles = 8;
+ else
+ params->rdsr_dummy_cycles = 4;
+
+ params->rd_reg_cmd = FIELD_GET(XSPI_PF1_DWORD2_RD_REG_CMD,
+ pfile1.dwords[XSPI_DWORD(2)]);
+ params->wr_reg_cmd = FIELD_GET(XSPI_PF1_DWORD2_WR_REG_CMD,
+ pfile1.dwords[XSPI_DWORD(2)]);
+
+ for (i = 0; i < ARRAY_SIZE(dummy); i++) {
+ if (params->octal_max_speed == dummy[i].speed_hz) {
+ params->dummy_cycles =
+ (dummy[i].mask &
+ pfile1.dwords[XSPI_DWORD(dummy[i].dwords)]) >>
+ dummy[i].shift;
+ break;
+ }
+ }
+ if (i == ARRAY_SIZE(dummy))
+ params->dummy_cycles = 20;
+
+out:
+ return ret;
+}
+
+/**
* spi_nor_parse_sfdp() - parse the Serial Flash Discoverable Parameters.
* @nor: pointer to a 'struct spi_nor'
* @params: pointer to the 'struct spi_nor_flash_parameter' to be
@@ -1171,7 +1272,6 @@ int spi_nor_parse_sfdp(struct spi_nor *nor,
/* Parse optional parameter tables. */
for (i = 0; i < header.nph; i++) {
param_header = &param_headers[i];
-
switch (SFDP_PARAM_HEADER_ID(param_header)) {
case SFDP_SECTOR_MAP_ID:
err = spi_nor_parse_smpt(nor, param_header, params);
@@ -1181,6 +1281,10 @@ int spi_nor_parse_sfdp(struct spi_nor *nor,
err = spi_nor_parse_4bait(nor, param_header, params);
break;

+ case SFDP_XSPI_PF1_ID:
+ err = spi_nor_parse_xspi_pf1(nor, param_header, params);
+ break;
+
default:
break;
}
--
1.9.1