Get maximum operation speed of device in octal mode from
BFPT 20th DWORD.

Signed-off-by: Mason Yang <masonccy...@mxic.com.tw>
---
 drivers/mtd/spi-nor/core.h |  2 ++
 drivers/mtd/spi-nor/sfdp.c | 36 ++++++++++++++++++++++++++++++++++++
 drivers/mtd/spi-nor/sfdp.h |  4 ++++
 3 files changed, 42 insertions(+)

diff --git a/drivers/mtd/spi-nor/core.h b/drivers/mtd/spi-nor/core.h
index de1e391..f644ed1 100644
--- a/drivers/mtd/spi-nor/core.h
+++ b/drivers/mtd/spi-nor/core.h
@@ -192,6 +192,7 @@ struct spi_nor_locking_ops {
  *
  * @size:              the flash memory density in bytes.
  * @page_size:         the page size of the SPI NOR flash memory.
+ * @octal_max_speed:   maximum operation speed of device in octal mode.
  * @hwcaps:            describes the read and page program hardware
  *                     capabilities.
  * @reads:             read capabilities ordered by priority: the higher index
@@ -214,6 +215,7 @@ struct spi_nor_locking_ops {
 struct spi_nor_flash_parameter {
        u64                             size;
        u32                             page_size;
+       u16                             octal_max_speed;
 
        struct spi_nor_hwcaps           hwcaps;
        struct spi_nor_read_command     reads[SNOR_CMD_READ_MAX];
diff --git a/drivers/mtd/spi-nor/sfdp.c b/drivers/mtd/spi-nor/sfdp.c
index 3685a3a..d7ef47a 100644
--- a/drivers/mtd/spi-nor/sfdp.c
+++ b/drivers/mtd/spi-nor/sfdp.c
@@ -4,6 +4,7 @@
  * Copyright (C) 2014, Freescale Semiconductor, Inc.
  */
 
+#include <linux/bitfield.h>
 #include <linux/slab.h>
 #include <linux/sort.h>
 #include <linux/mtd/spi-nor.h>
@@ -26,6 +27,12 @@
 #define SFDP_JESD216A_MINOR    5
 #define SFDP_JESD216B_MINOR    6
 
+/* Basic Flash Parameter Table 20th DWORD, Max operation speed of device */
+struct octal_max_speed {
+       u8 idx; /* Bits value */
+       u16 hz; /* MHz */
+};
+
 struct sfdp_header {
        u32             signature; /* Ox50444653U <=> "SFDP" */
        u8              minor;
@@ -440,6 +447,22 @@ static int spi_nor_parse_bfpt(struct spi_nor *nor,
        u32 addr;
        u16 half;
        u8 erase_mask;
+       static const struct octal_max_speed max_hz[] = {
+               /* Bits value, MHz */
+               { 0x0c, 400 },
+               { 0x0b, 333 },
+               { 0x0a, 266 },
+               { 0x09, 250 },
+               { 0x08, 200 },
+               { 0x07, 166 },
+               { 0x06, 133 },
+               { 0x05, 100 },
+               { 0x04,  80 },
+               { 0x03,  66 },
+               { 0x02,  50 },
+               { 0x01,  33 },
+       };
+       u8 idx;
 
        /* JESD216 Basic Flash Parameter Table length is at least 9 DWORDs. */
        if (bfpt_header->length < BFPT_DWORD_MAX_JESD216)
@@ -626,6 +649,19 @@ static int spi_nor_parse_bfpt(struct spi_nor *nor,
                return -ENOTSUPP;
        }
 
+       /* Octal mode max speed */
+       idx = max(FIELD_GET(BFPT_DWORD20_OCTAL_DTR_MAX_SPEED,
+                           bfpt.dwords[BFPT_DWORD(20)]),
+                 FIELD_GET(BFPT_DWORD20_OCTAL_STR_MAX_SPEED,
+                           bfpt.dwords[BFPT_DWORD(20)]));
+
+       for (i = 0; i < ARRAY_SIZE(max_hz); i++) {
+               if (max_hz[i].idx == idx) {
+                       params->octal_max_speed = max_hz[i].hz;
+                       break;
+               }
+       }
+
        return spi_nor_post_bfpt_fixups(nor, bfpt_header, &bfpt, params);
 }
 
diff --git a/drivers/mtd/spi-nor/sfdp.h b/drivers/mtd/spi-nor/sfdp.h
index e15e307..d8ee681 100644
--- a/drivers/mtd/spi-nor/sfdp.h
+++ b/drivers/mtd/spi-nor/sfdp.h
@@ -90,6 +90,10 @@ struct sfdp_bfpt {
 #define BFPT_DWORD18_CMD_EXT_RES               (0x2UL << 29) /* Reserved */
 #define BFPT_DWORD18_CMD_EXT_16B               (0x3UL << 29) /* 16-bit opcode 
*/
 
+#define BFPT_DWORD20_OCTAL_MAX_SPEED_MASK       GENMASK(31, 16)
+#define BFPT_DWORD20_OCTAL_DTR_MAX_SPEED        GENMASK(31, 28)
+#define BFPT_DWORD20_OCTAL_STR_MAX_SPEED        GENMASK(19, 16)
+
 struct sfdp_parameter_header {
        u8              id_lsb;
        u8              minor;
-- 
1.9.1

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