[PATCH v8 3/4] mtd: spi-nor: introduce Double Transfer Rate (DTR) SPI protocols
From: Cyrille Pitchen
Date: Tue Apr 25 2017 - 16:09:50 EST
From: Cyrille Pitchen <cyrille.pitchen@xxxxxxxxx>
This patch introduces support to Double Transfer Rate (DTR) SPI protocols.
DTR is used only for Fast Read operations.
According to manufacturer datasheets, whatever the number of I/O lines
used during instruction (x) and address/mode/dummy (y) clock cycles, DTR
is used only during data (z) clock cycles of SPI x-y-z protocols.
Signed-off-by: Cyrille Pitchen <cyrille.pitchen@xxxxxxxxx>
---
drivers/mtd/spi-nor/spi-nor.c | 10 +++++++++
include/linux/mtd/spi-nor.h | 48 +++++++++++++++++++++++++++++++++----------
2 files changed, 47 insertions(+), 11 deletions(-)
diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
index 3421a42b4120..9f0956d56dc9 100644
--- a/drivers/mtd/spi-nor/spi-nor.c
+++ b/drivers/mtd/spi-nor/spi-nor.c
@@ -203,6 +203,10 @@ static inline u8 spi_nor_convert_3to4_read(u8 opcode)
{ SPINOR_OP_READ_1_2_2, SPINOR_OP_READ_1_2_2_4B },
{ SPINOR_OP_READ_1_1_4, SPINOR_OP_READ_1_1_4_4B },
{ SPINOR_OP_READ_1_4_4, SPINOR_OP_READ_1_4_4_4B },
+
+ { SPINOR_OP_READ_1_1_1_DTR, SPINOR_OP_READ_1_1_1_DTR_4B },
+ { SPINOR_OP_READ_1_2_2_DTR, SPINOR_OP_READ_1_2_2_DTR_4B },
+ { SPINOR_OP_READ_1_4_4_DTR, SPINOR_OP_READ_1_4_4_DTR_4B },
};
return spi_nor_convert_opcode(opcode, spi_nor_3to4_read,
@@ -1509,16 +1513,19 @@ struct spi_nor_pp_command {
enum spi_nor_read_command_index {
SNOR_CMD_READ,
SNOR_CMD_READ_FAST,
+ SNOR_CMD_READ_1_1_1_DTR,
/* Dual SPI */
SNOR_CMD_READ_1_1_2,
SNOR_CMD_READ_1_2_2,
SNOR_CMD_READ_2_2_2,
+ SNOR_CMD_READ_1_2_2_DTR,
/* Quad SPI */
SNOR_CMD_READ_1_1_4,
SNOR_CMD_READ_1_4_4,
SNOR_CMD_READ_4_4_4,
+ SNOR_CMD_READ_1_4_4_DTR,
SNOR_CMD_READ_MAX
};
@@ -1646,12 +1653,15 @@ static int spi_nor_hwcaps_read2cmd(u32 hwcaps)
static const int hwcaps_read2cmd[][2] = {
{ SNOR_HWCAPS_READ, SNOR_CMD_READ },
{ SNOR_HWCAPS_READ_FAST, SNOR_CMD_READ_FAST },
+ { SNOR_HWCAPS_READ_1_1_1_DTR, SNOR_CMD_READ_1_1_1_DTR },
{ SNOR_HWCAPS_READ_1_1_2, SNOR_CMD_READ_1_1_2 },
{ SNOR_HWCAPS_READ_1_2_2, SNOR_CMD_READ_1_2_2 },
{ SNOR_HWCAPS_READ_2_2_2, SNOR_CMD_READ_2_2_2 },
+ { SNOR_HWCAPS_READ_1_2_2_DTR, SNOR_CMD_READ_1_2_2_DTR },
{ SNOR_HWCAPS_READ_1_1_4, SNOR_CMD_READ_1_1_4 },
{ SNOR_HWCAPS_READ_1_4_4, SNOR_CMD_READ_1_4_4 },
{ SNOR_HWCAPS_READ_4_4_4, SNOR_CMD_READ_4_4_4 },
+ { SNOR_HWCAPS_READ_1_4_4_DTR, SNOR_CMD_READ_1_4_4_DTR },
};
return spi_nor_hwcaps2cmd(hwcaps, hwcaps_read2cmd,
diff --git a/include/linux/mtd/spi-nor.h b/include/linux/mtd/spi-nor.h
index 60db1585f94c..313dbe56f31a 100644
--- a/include/linux/mtd/spi-nor.h
+++ b/include/linux/mtd/spi-nor.h
@@ -73,6 +73,15 @@
#define SPINOR_OP_BE_32K_4B 0x5c /* Erase 32KiB block */
#define SPINOR_OP_SE_4B 0xdc /* Sector erase (usually 64KiB) */
+/* Double Transfer Rate opcodes - defined in JEDEC JESD216B. */
+#define SPINOR_OP_READ_1_1_1_DTR 0x0d
+#define SPINOR_OP_READ_1_2_2_DTR 0xbd
+#define SPINOR_OP_READ_1_4_4_DTR 0xed
+
+#define SPINOR_OP_READ_1_1_1_DTR_4B 0x0e
+#define SPINOR_OP_READ_1_2_2_DTR_4B 0xbe
+#define SPINOR_OP_READ_1_4_4_DTR_4B 0xee
+
/* Used for SST flashes only. */
#define SPINOR_OP_BP 0x02 /* Byte program */
#define SPINOR_OP_WRDI 0x04 /* Write disable */
@@ -138,10 +147,15 @@
((((unsigned long)(_nbits)) << SNOR_PROTO_DATA_SHIFT) & \
SNOR_PROTO_DATA_MASK)
+#define SNOR_PROTO_IS_DTR BIT(24) /* Double Transfer Rate */
+
#define SNOR_PROTO_STR(_inst_nbits, _addr_nbits, _data_nbits) \
(SNOR_PROTO_INST(_inst_nbits) | \
SNOR_PROTO_ADDR(_addr_nbits) | \
SNOR_PROTO_DATA(_data_nbits))
+#define SNOR_PROTO_DTR(_inst_nbits, _addr_nbits, _data_nbits) \
+ (SNOR_PROTO_IS_DTR | \
+ SNOR_PROTO_STR(_inst_nbits, _addr_nbits, _data_nbits))
enum spi_nor_protocol {
SNOR_PROTO_1_1_1 = SNOR_PROTO_STR(1, 1, 1),
@@ -151,8 +165,17 @@ enum spi_nor_protocol {
SNOR_PROTO_1_4_4 = SNOR_PROTO_STR(1, 4, 4),
SNOR_PROTO_2_2_2 = SNOR_PROTO_STR(2, 2, 2),
SNOR_PROTO_4_4_4 = SNOR_PROTO_STR(4, 4, 4),
+
+ SNOR_PROTO_1_1_1_DTR = SNOR_PROTO_DTR(1, 1, 1),
+ SNOR_PROTO_1_2_2_DTR = SNOR_PROTO_DTR(1, 2, 2),
+ SNOR_PROTO_1_4_4_DTR = SNOR_PROTO_DTR(1, 4, 4),
};
+static inline bool spi_nor_protocol_is_dtr(enum spi_nor_protocol proto)
+{
+ return !!(proto & SNOR_PROTO_IS_DTR);
+}
+
static inline u8 spi_nor_get_protocol_inst_nbits(enum spi_nor_protocol proto)
{
return ((unsigned long)(proto & SNOR_PROTO_INST_MASK)) >>
@@ -288,19 +311,22 @@ struct spi_nor_hwcaps {
* As a matter of performances, it is relevant to use Quad SPI protocols first,
* then Dual SPI protocols before Fast Read and lastly (Slow) Read.
*/
-#define SNOR_HWCAPS_READ_MASK GENMASK(7, 0)
+#define SNOR_HWCAPS_READ_MASK GENMASK(10, 0)
#define SNOR_HWCAPS_READ BIT(0)
#define SNOR_HWCAPS_READ_FAST BIT(1)
-
-#define SNOR_HWCAPS_READ_DUAL GENMASK(4, 2)
-#define SNOR_HWCAPS_READ_1_1_2 BIT(2)
-#define SNOR_HWCAPS_READ_1_2_2 BIT(3)
-#define SNOR_HWCAPS_READ_2_2_2 BIT(4)
-
-#define SNOR_HWCAPS_READ_QUAD GENMASK(7, 5)
-#define SNOR_HWCAPS_READ_1_1_4 BIT(5)
-#define SNOR_HWCAPS_READ_1_4_4 BIT(6)
-#define SNOR_HWCAPS_READ_4_4_4 BIT(7)
+#define SNOR_HWCAPS_READ_1_1_1_DTR BIT(2)
+
+#define SNOR_HWCAPS_READ_DUAL GENMASK(6, 3)
+#define SNOR_HWCAPS_READ_1_1_2 BIT(3)
+#define SNOR_HWCAPS_READ_1_2_2 BIT(4)
+#define SNOR_HWCAPS_READ_2_2_2 BIT(5)
+#define SNOR_HWCAPS_READ_1_2_2_DTR BIT(6)
+
+#define SNOR_HWCAPS_READ_QUAD GENMASK(10, 7)
+#define SNOR_HWCAPS_READ_1_1_4 BIT(7)
+#define SNOR_HWCAPS_READ_1_4_4 BIT(8)
+#define SNOR_HWCAPS_READ_4_4_4 BIT(9)
+#define SNOR_HWCAPS_READ_1_4_4_DTR BIT(10)
/*
* Page Program capabilities.
--
2.9.3