This patch adds the DDR quad read support by the following:
[1] add SPI_NOR_DDR_QUAD read mode.
[2] add DDR Quad read opcodes:
SPINOR_OP_READ_1_4_4_D / SPINOR_OP_READ4_1_4_4_D
[3] add set_ddr_quad_mode() to initialize for the DDR quad read.
Currently it only works for Spansion NOR.
[3] about the dummy cycles.
We set the dummy with 8 for DDR quad read by default.
The m25p80.c can not support the DDR quad read, but the SPI NOR controller
can set the dummy value in its child DT node, and the SPI NOR framework
can parse it out.
Test this patch for Spansion s25fl128s NOR flash.
Signed-off-by: Huang Shijie <b32955@xxxxxxxxxxxxx>
---
drivers/mtd/spi-nor/spi-nor.c | 54 +++++++++++++++++++++++++++++++++++++++-
include/linux/mtd/spi-nor.h | 8 ++++-
2 files changed, 58 insertions(+), 4 deletions(-)
diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
index f374e44..e0bc11a 100644
--- a/drivers/mtd/spi-nor/spi-nor.c
+++ b/drivers/mtd/spi-nor/spi-nor.c
@@ -73,7 +73,20 @@ static int read_cr(struct spi_nor *nor)
*/
static inline int spi_nor_read_dummy_cycles(struct spi_nor *nor)
{
+ u32 dummy;
+
switch (nor->flash_read) {
+ case SPI_NOR_DDR_QUAD:
+ /*
+ * The m25p80.c can not support the DDR quad read.
+ * We set the dummy cycles to 8 by default. The SPI NOR
+ * controller driver can set it in its child DT node.
+ * We parse it out here.
+ */
+ if (nor->np && !of_property_read_u32(nor->np,
+ "spi-nor,ddr-quad-read-dummy", &dummy)) {
+ return dummy;
+ }
case SPI_NOR_FAST:
case SPI_NOR_DUAL:
case SPI_NOR_QUAD:
@@ -402,6 +415,7 @@ struct flash_info {
#define SECT_4K_PMC 0x10 /* SPINOR_OP_BE_4K_PMC works uniformly */
#define SPI_NOR_DUAL_READ 0x20 /* Flash supports Dual Read */
#define SPI_NOR_QUAD_READ 0x40 /* Flash supports Quad Read */
+#define SPI_NOR_DDR_QUAD_READ 0x80 /* Flash supports DDR Quad Read */
};
#define INFO(_jedec_id, _ext_id, _sector_size, _n_sectors, _flags) \
@@ -846,6 +860,24 @@ static int spansion_quad_enable(struct spi_nor *nor)
return 0;
}
+static int set_ddr_quad_mode(struct spi_nor *nor, u32 jedec_id)
+{
+ int status;
+
+ switch (JEDEC_MFR(jedec_id)) {
+ case CFI_MFR_AMD: /* Spansion, actually */
+ status = spansion_quad_enable(nor);
+ if (status) {
+ dev_err(nor->dev,
+ "Spansion DDR quad-read not enabled\n");
+ return status;
+ }
+ return status;
+ default:
+ return -EINVAL;
+ }
+}
+
static int set_quad_mode(struct spi_nor *nor, u32 jedec_id)
{
int status;
@@ -1016,8 +1048,15 @@ int spi_nor_scan(struct spi_nor *nor, const struct spi_device_id *id,
if (info->flags & SPI_NOR_NO_FR)
nor->flash_read = SPI_NOR_NORMAL;
- /* Quad/Dual-read mode takes precedence over fast/normal */
- if (mode == SPI_NOR_QUAD && info->flags & SPI_NOR_QUAD_READ) {
+ /* DDR Quad/Quad/Dual-read mode takes precedence over fast/normal */
+ if (mode == SPI_NOR_DDR_QUAD && info->flags & SPI_NOR_DDR_QUAD_READ) {
+ ret = set_ddr_quad_mode(nor, info->jedec_id);
+ if (ret) {
+ dev_err(dev, "DDR quad mode not supported\n");
+ return ret;
+ }
+ nor->flash_read = SPI_NOR_DDR_QUAD;
+ } else if (mode == SPI_NOR_QUAD && info->flags & SPI_NOR_QUAD_READ) {
ret = set_quad_mode(nor, info->jedec_id);
if (ret) {
dev_err(dev, "quad mode not supported\n");
@@ -1030,6 +1069,14 @@ int spi_nor_scan(struct spi_nor *nor, const struct spi_device_id *id,
/* Default commands */
switch (nor->flash_read) {
+ case SPI_NOR_DDR_QUAD:
+ if (JEDEC_MFR(info->jedec_id) == CFI_MFR_AMD) { /* Spansion */
+ nor->read_opcode = SPINOR_OP_READ_1_4_4_D;
+ } else {
+ dev_err(dev, "DDR Quad Read is not supported.\n");
+ return -EINVAL;
+ }
+ break;
case SPI_NOR_QUAD:
nor->read_opcode = SPINOR_OP_READ_1_1_4;
break;
@@ -1057,6 +1104,9 @@ int spi_nor_scan(struct spi_nor *nor, const struct spi_device_id *id,
if (JEDEC_MFR(info->jedec_id) == CFI_MFR_AMD) {
/* Dedicated 4-byte command set */
switch (nor->flash_read) {
+ case SPI_NOR_DDR_QUAD:
+ nor->read_opcode = SPINOR_OP_READ4_1_4_4_D;
+ break;
case SPI_NOR_QUAD:
nor->read_opcode = SPINOR_OP_READ4_1_1_4;
break;
diff --git a/include/linux/mtd/spi-nor.h b/include/linux/mtd/spi-nor.h
index 48fe9fc..d191a6b 100644
--- a/include/linux/mtd/spi-nor.h
+++ b/include/linux/mtd/spi-nor.h
@@ -12,10 +12,11 @@
/*
* Note on opcode nomenclature: some opcodes have a format like
- * SPINOR_OP_FUNCTION{4,}_x_y_z. The numbers x, y, and z stand for the number
+ * SPINOR_OP_FUNCTION{4,}_x_y_z{_D}. The numbers x, y, and z stand for the number
* of I/O lines used for the opcode, address, and data (respectively). The
* FUNCTION has an optional suffix of '4', to represent an opcode which
- * requires a 4-byte (32-bit) address.
+ * requires a 4-byte (32-bit) address. The suffix of 'D' stands for the
+ * DDR mode.
*/
/* Flash opcodes. */
@@ -26,6 +27,7 @@
#define SPINOR_OP_READ_FAST 0x0b /* Read data bytes (high frequency) */
#define SPINOR_OP_READ_1_1_2 0x3b /* Read data bytes (Dual SPI) */
#define SPINOR_OP_READ_1_1_4 0x6b /* Read data bytes (Quad SPI) */
+#define SPINOR_OP_READ_1_4_4_D 0xed /* Read data bytes (DDR Quad SPI) */
#define SPINOR_OP_PP 0x02 /* Page program (up to 256 bytes) */
#define SPINOR_OP_BE_4K 0x20 /* Erase 4KiB block */
#define SPINOR_OP_BE_4K_PMC 0xd7 /* Erase 4KiB block on PMC chips */
@@ -40,6 +42,7 @@
#define SPINOR_OP_READ4_FAST 0x0c /* Read data bytes (high frequency) */
#define SPINOR_OP_READ4_1_1_2 0x3c /* Read data bytes (Dual SPI) */
#define SPINOR_OP_READ4_1_1_4 0x6c /* Read data bytes (Quad SPI) */
+#define SPINOR_OP_READ4_1_4_4_D 0xee /* Read data bytes (DDR Quad SPI) */
#define SPINOR_OP_PP_4B 0x12 /* Page program (up to 256 bytes) */
#define SPINOR_OP_SE_4B 0xdc /* Sector erase (usually 64KiB) */
@@ -74,6 +77,7 @@ enum read_mode {
SPI_NOR_FAST,
SPI_NOR_DUAL,
SPI_NOR_QUAD,
+ SPI_NOR_DDR_QUAD,
};
/**
--
1.7.2.rc3
--
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