[PATCH v1 2/7] mtd: spi-nor: add DDR quad read support
Huang Shijie
b32955 at freescale.com
Wed Apr 23 03:16:50 PDT 2014
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] set the dummy with 8 for DDR quad read.
The m25p80.c can not support the DDR quad read, the SPI NOR controller
can set the dummy value in its driver, such as fsl-quadspi.c.
Test this patch for Spansion s25fl128s NOR flash.
Signed-off-by: Huang Shijie <b32955 at freescale.com>
---
drivers/mtd/spi-nor/spi-nor.c | 50 +++++++++++++++++++++++++++++++++++++++-
include/linux/mtd/spi-nor.h | 8 +++++-
2 files changed, 54 insertions(+), 4 deletions(-)
diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
index 1a12f81..e2f69db 100644
--- a/drivers/mtd/spi-nor/spi-nor.c
+++ b/drivers/mtd/spi-nor/spi-nor.c
@@ -74,6 +74,15 @@ static int read_cr(struct spi_nor *nor)
static inline int spi_nor_read_dummy_cycles(struct spi_nor *nor)
{
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. If the SPI NOR
+ * controller driver has already set it before call the
+ * spi_nor_scan(), we just keep it as it is.
+ */
+ if (nor->read_dummy)
+ return nor->read_dummy;
case SPI_NOR_FAST:
case SPI_NOR_DUAL:
case SPI_NOR_QUAD:
@@ -402,6 +411,7 @@ 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 +856,24 @@ 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 -EINVAL;
+ }
+ return status;
+ default:
+ return -EINVAL;
+ }
+}
+
static int set_quad_mode(struct spi_nor *nor, u32 jedec_id)
{
int status;
@@ -1016,8 +1044,15 @@ 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 +1065,14 @@ 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 +1100,9 @@ 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 5324184..fea7769 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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