From f6adec1af4b2f5d3012480c6cdce7743b74a6156 Mon Sep 17 00:00:00 2001
From: Pratyush Yadav
Date: Sat, 26 Jun 2021 00:47:29 +0530
Subject: [PATCH] mtd: spi-nor-core: Allow using Micron mt35xu512aba in Octal
DTR mode
Since this flash doesn't have a Profile 1.0 table, the Octal DTR
capabilities are enabled in the post SFDP fixup, along with the 8D-8D-8D
fast read settings.
Enable Octal DTR mode with 20 dummy cycles to allow running at the
maximum supported frequency of 200Mhz.
Signed-off-by: Pratyush Yadav
Reviewed-by: Jagan Teki
---
drivers/mtd/spi/Kconfig | 8 ++++
drivers/mtd/spi/spi-nor-core.c | 87 ++++++++++++++++++++++++++++++++++
drivers/mtd/spi/spi-nor-ids.c | 4 +-
include/linux/mtd/spi-nor.h | 6 +++
4 files changed, 104 insertions(+), 1 deletion(-)
diff --git a/drivers/mtd/spi/Kconfig b/drivers/mtd/spi/Kconfig
index 98c0b23478..1b2ef37e92 100644
--- a/drivers/mtd/spi/Kconfig
+++ b/drivers/mtd/spi/Kconfig
@@ -180,6 +180,14 @@ config SPI_FLASH_STMICRO
help
Add support for various STMicro SPI flash chips (M25Pxxx and N25Qxxx)
+config SPI_FLASH_MT35XU
+ bool "Micron MT35XU chip support"
+ depends on SPI_FLASH_STMICRO
+ help
+ Add support for the Micron MT35XU chip. This is a separate config
+ because the fixup hooks for this flash add extra size overhead. Boards
+ that don't use the flash can disable this to save space.
+
config SPI_FLASH_SST
bool "SST SPI flash support"
help
diff --git a/drivers/mtd/spi/spi-nor-core.c b/drivers/mtd/spi/spi-nor-core.c
index 3a1060b04b..8dd44c0f1e 100644
--- a/drivers/mtd/spi/spi-nor-core.c
+++ b/drivers/mtd/spi/spi-nor-core.c
@@ -3148,6 +3148,88 @@ static struct spi_nor_fixups s28hs512t_fixups = {
};
#endif /* CONFIG_SPI_FLASH_S28HS512T */
+#ifdef CONFIG_SPI_FLASH_MT35XU
+static int spi_nor_micron_octal_dtr_enable(struct spi_nor *nor)
+{
+ struct spi_mem_op op;
+ u8 buf;
+ u8 addr_width = 3;
+ int ret;
+
+ /* Set dummy cycles for Fast Read to the default of 20. */
+ ret = write_enable(nor);
+ if (ret)
+ return ret;
+
+ buf = 20;
+ op = (struct spi_mem_op)
+ SPI_MEM_OP(SPI_MEM_OP_CMD(SPINOR_OP_MT_WR_ANY_REG, 1),
+ SPI_MEM_OP_ADDR(addr_width, SPINOR_REG_MT_CFR1V, 1),
+ SPI_MEM_OP_NO_DUMMY,
+ SPI_MEM_OP_DATA_OUT(1, &buf, 1));
+ ret = spi_mem_exec_op(nor->spi, &op);
+ if (ret)
+ return ret;
+
+ ret = spi_nor_wait_till_ready(nor);
+ if (ret)
+ return ret;
+
+ nor->read_dummy = 20;
+
+ ret = write_enable(nor);
+ if (ret)
+ return ret;
+
+ buf = SPINOR_MT_OCT_DTR;
+ op = (struct spi_mem_op)
+ SPI_MEM_OP(SPI_MEM_OP_CMD(SPINOR_OP_MT_WR_ANY_REG, 1),
+ SPI_MEM_OP_ADDR(addr_width, SPINOR_REG_MT_CFR0V, 1),
+ SPI_MEM_OP_NO_DUMMY,
+ SPI_MEM_OP_DATA_OUT(1, &buf, 1));
+ ret = spi_mem_exec_op(nor->spi, &op);
+ if (ret) {
+ dev_err(nor->dev, "Failed to enable octal DTR mode\n");
+ return ret;
+ }
+
+ return 0;
+}
+
+static void mt35xu512aba_default_init(struct spi_nor *nor)
+{
+ nor->octal_dtr_enable = spi_nor_micron_octal_dtr_enable;
+}
+
+static void mt35xu512aba_post_sfdp_fixup(struct spi_nor *nor,
+ struct spi_nor_flash_parameter *params)
+{
+ /* Set the Fast Read settings. */
+ params->hwcaps.mask |= SNOR_HWCAPS_READ_8_8_8_DTR;
+ spi_nor_set_read_settings(¶ms->reads[SNOR_CMD_READ_8_8_8_DTR],
+ 0, 20, SPINOR_OP_MT_DTR_RD,
+ SNOR_PROTO_8_8_8_DTR);
+
+ params->hwcaps.mask |= SNOR_HWCAPS_PP_8_8_8_DTR;
+
+ nor->cmd_ext_type = SPI_NOR_EXT_REPEAT;
+ params->rdsr_dummy = 8;
+ params->rdsr_addr_nbytes = 0;
+
+ /*
+ * The BFPT quad enable field is set to a reserved value so the quad
+ * enable function is ignored by spi_nor_parse_bfpt(). Make sure we
+ * disable it.
+ */
+ params->quad_enable = NULL;
+}
+
+static struct spi_nor_fixups mt35xu512aba_fixups = {
+ .default_init = mt35xu512aba_default_init,
+ .post_sfdp = mt35xu512aba_post_sfdp_fixup,
+};
+#endif /* CONFIG_SPI_FLASH_MT35XU */
+
/** spi_nor_octal_dtr_enable() - enable Octal DTR I/O if needed
* @nor: pointer to a 'struct spi_nor'
*
@@ -3295,6 +3377,11 @@ void spi_nor_set_fixups(struct spi_nor *nor)
if (!strcmp(nor->info->name, "s28hs512t"))
nor->fixups = &s28hs512t_fixups;
#endif
+
+#ifdef CONFIG_SPI_FLASH_MT35XU
+ if (!strcmp(nor->info->name, "mt35xu512aba"))
+ nor->fixups = &mt35xu512aba_fixups;
+#endif
}
int spi_nor_scan(struct spi_nor *nor)
diff --git a/drivers/mtd/spi/spi-nor-ids.c b/drivers/mtd/spi/spi-nor-ids.c
index bbed88a4b7..59f2d3e4d6 100644
--- a/drivers/mtd/spi/spi-nor-ids.c
+++ b/drivers/mtd/spi/spi-nor-ids.c
@@ -193,7 +193,9 @@ const struct flash_info spi_nor_ids[] = {
{ INFO("n25q00a", 0x20bb21, 0, 64 * 1024, 2048, SECT_4K | USE_FSR | SPI_NOR_QUAD_READ | NO_CHIP_ERASE) },
{ INFO("mt25ql01g", 0x21ba20, 0, 64 * 1024, 2048, SECT_4K | USE_FSR | SPI_NOR_QUAD_READ | NO_CHIP_ERASE) },
{ INFO("mt25qu02g", 0x20bb22, 0, 64 * 1024, 4096, SECT_4K | USE_FSR | SPI_NOR_QUAD_READ | NO_CHIP_ERASE) },
- { INFO("mt35xu512aba", 0x2c5b1a, 0, 128 * 1024, 512, USE_FSR | SPI_NOR_OCTAL_READ | SPI_NOR_4B_OPCODES) },
+#ifdef CONFIG_SPI_FLASH_MT35XU
+ { INFO("mt35xu512aba", 0x2c5b1a, 0, 128 * 1024, 512, USE_FSR | SPI_NOR_OCTAL_READ | SPI_NOR_4B_OPCODES | SPI_NOR_OCTAL_DTR_READ) },
+#endif /* CONFIG_SPI_FLASH_MT35XU */
{ INFO("mt35xu02g", 0x2c5b1c, 0, 128 * 1024, 2048, USE_FSR | SPI_NOR_OCTAL_READ | SPI_NOR_4B_OPCODES) },
#endif
#ifdef CONFIG_SPI_FLASH_SPANSION /* SPANSION */
diff --git a/include/linux/mtd/spi-nor.h b/include/linux/mtd/spi-nor.h
index 6ece401b37..d68e48fd94 100644
--- a/include/linux/mtd/spi-nor.h
+++ b/include/linux/mtd/spi-nor.h
@@ -126,6 +126,12 @@
/* Used for Micron flashes only. */
#define SPINOR_OP_RD_EVCR 0x65 /* Read EVCR register */
#define SPINOR_OP_WD_EVCR 0x61 /* Write EVCR register */
+#define SPINOR_OP_MT_DTR_RD 0xfd /* Fast Read opcode in DTR mode */
+#define SPINOR_OP_MT_RD_ANY_REG 0x85 /* Read volatile register */
+#define SPINOR_OP_MT_WR_ANY_REG 0x81 /* Write volatile register */
+#define SPINOR_REG_MT_CFR0V 0x00 /* For setting octal DTR mode */
+#define SPINOR_REG_MT_CFR1V 0x01 /* For setting dummy cycles */
+#define SPINOR_MT_OCT_DTR 0xe7 /* Enable Octal DTR with DQS. */
/* Status Register bits. */
#define SR_WIP BIT(0) /* Write in progress */
--
2.39.5