From 93cd6f8a8a53ac2ff9b14dc3b37f53f5a45aaaa6 Mon Sep 17 00:00:00 2001 From: Han Xu Date: Tue, 3 Nov 2015 16:52:25 -0600 Subject: [PATCH] MLK-11941: mtd: spi-nor: add DDR quad read support 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. Signed-off-by: Han Xu --- drivers/mtd/spi-nor/spi-nor.c | 56 +++++++++++++++++++++++++++++++++-- include/linux/mtd/spi-nor.h | 8 +++-- 2 files changed, 60 insertions(+), 4 deletions(-) diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c index 21dde5249085..d26a0a161e47 100644 --- a/drivers/mtd/spi-nor/spi-nor.c +++ b/drivers/mtd/spi-nor/spi-nor.c @@ -75,6 +75,7 @@ struct flash_info { * bit. Must be used with * SPI_NOR_HAS_LOCK. */ +#define SPI_NOR_DDR_QUAD_READ BIT(10) /* Flash supports DDR Quad Read */ }; #define JEDEC_MFR(info) ((info)->id[0]) @@ -146,6 +147,21 @@ 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: + { + struct device_node *np = spi_nor_get_flash_node(nor); + u32 dummy; + + /* + * 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 (of_property_read_u32(np,"spi-nor,ddr-quad-read-dummy", + &dummy)) + return dummy; + } case SPI_NOR_FAST: case SPI_NOR_DUAL: case SPI_NOR_QUAD: @@ -1272,6 +1288,24 @@ static int spansion_quad_enable(struct spi_nor *nor) return 0; } +static int set_ddr_quad_mode(struct spi_nor *nor, const struct flash_info *info) +{ + int status; + + switch (JEDEC_MFR(info)) { + 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, const struct flash_info *info) { int status; @@ -1440,8 +1474,15 @@ int spi_nor_scan(struct spi_nor *nor, const char *name, enum read_mode mode) 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); + 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); if (ret) { dev_err(dev, "quad mode not supported\n"); @@ -1454,6 +1495,14 @@ int spi_nor_scan(struct spi_nor *nor, const char *name, enum read_mode mode) /* Default commands */ switch (nor->flash_read) { + case SPI_NOR_DDR_QUAD: + if (JEDEC_MFR(info) == 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; @@ -1481,6 +1530,9 @@ int spi_nor_scan(struct spi_nor *nor, const char *name, enum read_mode mode) if (JEDEC_MFR(info) == SNOR_MFR_SPANSION) { /* 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 c425c7b4c2a0..1d0b9fb9f628 100644 --- a/include/linux/mtd/spi-nor.h +++ b/include/linux/mtd/spi-nor.h @@ -31,10 +31,11 @@ /* * 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. */ @@ -45,6 +46,7 @@ #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 0xeb /* 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 */ @@ -60,6 +62,7 @@ #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) */ @@ -105,6 +108,7 @@ enum read_mode { SPI_NOR_FAST, SPI_NOR_DUAL, SPI_NOR_QUAD, + SPI_NOR_DDR_QUAD, }; #define SPI_NOR_MAX_CMD_SIZE 8 -- 2.17.1