[PATCH 1/4] mtd: spi-nor: macronix: add support for Macronix octaflash

JaimeLiao
2021-08-13T12:20:00Z

Follow patch "f6adec1af4b2f5d3012480c6cdce7743b74a6156" for adding
Macronix flash in Octal DTR mode.
Enable Octal DTR mode with 20 dummy cycles to allow running at the
maximum supported frequency.

Signed-off-by: JaimeLiao <jaimeliao.tw@gmail.com>
---
drivers/mtd/spi/spi-nor-core.c | 75 ++++++++++++++++++++++++++++++++++
include/linux/mtd/spi-nor.h | 13 +++++-
2 files changed, 86 insertions(+), 2 deletions(-)

diff --git a/drivers/mtd/spi/spi-nor-core.c b/drivers/mtd/spi/spi-nor-core.c
index d5d905fa5a..6b195b1fd3 100644
--- a/drivers/mtd/spi/spi-nor-core.c
+++ b/drivers/mtd/spi/spi-nor-core.c
@@ -3489,6 +3489,77 @@ static struct spi_nor_fixups mt35xu512aba_fixups = {
};
#endif /* CONFIG_SPI_FLASH_MT35XU */

+#ifdef CONFIG_SPI_FLASH_MACRONIX
+/**
+ * spi_nor_macronix_octal_dtr_enable() - set DTR OPI Enable bit in Configuration Register 2.
+ * @nor: pointer to a 'struct spi_nor'
+ *
+ * Set the DTR OPI Enable (DOPI) bit in Configuration Register 2.
+ *
+ * bit 2 of Configuration Register 2 is the DOPI bit for Macronix like OPI memories.
+ *
+ * Return: 0 on success, -errno otherwise.
+ */
+static int spi_nor_macronix_octal_dtr_enable(struct spi_nor *nor)
+{
+ struct spi_mem_op op;
+ int ret;
+ u8 buf;
+
+ write_enable(nor);
+
+ buf = SPINOR_REG_MXIC_DC_20;
+ op = (struct spi_mem_op)
+ SPI_MEM_OP(SPI_MEM_OP_CMD(SPINOR_OP_WR_CR2, 1),
+ SPI_MEM_OP_ADDR(4, SPINOR_REG_MXIC_CR2_DC, 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 = MXIC_MAX_DC;
+ write_enable(nor);
+
+ buf = SPINOR_REG_MXIC_OPI_DTR_EN;
+ op = (struct spi_mem_op)
+ SPI_MEM_OP(SPI_MEM_OP_CMD(SPINOR_OP_WR_CR2, 1),
+ SPI_MEM_OP_ADDR(4, SPINOR_REG_MXIC_CR2_MODE, 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;
+ }
+ nor->reg_proto = SNOR_PROTO_8_8_8_DTR;
+
+ return 0;
+}
+
+static void macronix_default_init(struct spi_nor *nor)
+{
+ nor->octal_dtr_enable = spi_nor_macronix_octal_dtr_enable;
+}
+
+static void macronix_post_sfdp_fixup(struct spi_nor *nor,
+ struct spi_nor_flash_parameter *params)
+{
+ params->hwcaps.mask |= SNOR_HWCAPS_PP_8_8_8_DTR;
+}
+
+static struct spi_nor_fixups macronix_fixups = {
+ .default_init = macronix_default_init,
+ .post_sfdp = macronix_post_sfdp_fixup,
+};
+#endif /* CONFIG_SPI_FLASH_MACRONIX */
+
/** spi_nor_octal_dtr_enable() - enable Octal DTR I/O if needed
* @nor: pointer to a 'struct spi_nor'
*
@@ -3655,6 +3726,10 @@ void spi_nor_set_fixups(struct spi_nor *nor)
if (!strcmp(nor->info->name, "mt35xu512aba"))
nor->fixups = &mt35xu512aba_fixups;
#endif
+
+#ifdef CONFIG_SPI_FLASH_MACRONIX
+ nor->fixups = &macronix_fixups;
+#endif
}

int spi_nor_scan(struct spi_nor *nor)
diff --git a/include/linux/mtd/spi-nor.h b/include/linux/mtd/spi-nor.h
index 7ddc4ba2bf..2ad579f66d 100644
--- a/include/linux/mtd/spi-nor.h
+++ b/include/linux/mtd/spi-nor.h
@@ -116,8 +116,17 @@
#define XSR_RDY BIT(7) /* Ready */

/* Used for Macronix and Winbond flashes. */
-#define SPINOR_OP_EN4B 0xb7 /* Enter 4-byte mode */
-#define SPINOR_OP_EX4B 0xe9 /* Exit 4-byte mode */
+#define SPINOR_OP_EN4B 0xb7 /* Enter 4-byte mode */
+#define SPINOR_OP_EX4B 0xe9 /* Exit 4-byte mode */
+#define SPINOR_OP_RD_CR2 0x71 /* Read configuration register 2 */
+#define SPINOR_OP_WR_CR2 0x72 /* Write configuration register 2 */
+#define SPINOR_OP_MXIC_DTR_RD 0xee /* Fast Read opcode in DTR mode */
+#define SPINOR_REG_MXIC_CR2_MODE 0x00000000 /* For setting octal DTR mode */
+#define SPINOR_REG_MXIC_OPI_DTR_EN 0x2 /* Enable Octal DTR */
+#define SPINOR_REG_MXIC_OPI_DTR_DIS 0x1 /* Disable Octal DTR */
+#define SPINOR_REG_MXIC_CR2_DC 0x00000300 /* For setting dummy cycles */
+#define SPINOR_REG_MXIC_DC_20 0x0 /* Setting dummy cycles to 20 */
+#define MXIC_MAX_DC 20 /* Maximum value of dummy cycles */

/* Used for Spansion flashes only. */
#define SPINOR_OP_BRWR 0x17 /* Bank register write */
--
2.17.1