[PATCH v2 6/6] mtd: spi-nor: macronix: Add support for mx66lm1g45g

Tudor Ambarus
2022-03-11T08:02:24Z

mx66lm1g45g supports just 1-1-1, 8-8-8 and 8D-8D-8D modes. There are
versions of mx66lm1g45g which do not support SFDP, thus use
SPI_NOR_SKIP_SFDP. The RDID command issued through the octal peripheral
interface outputs data always in STR mode for whatever reason. Since
8D-8D-8S is not common, avoid reading the ID when enabling the octal dtr
mode. Instead, read back the CR2 to check if the switch was successful.
Tested in 1-1-1 and 8d-8d-8d modes using sama7g5 QSPI IP.

Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Link: https://lore.kernel.org/r/20220209133656.374903-8-tudor.ambarus@microchip.com
---
drivers/mtd/spi-nor/macronix.c | 130 +++++++++++++++++++++++++++++++++
1 file changed, 130 insertions(+)

diff --git a/drivers/mtd/spi-nor/macronix.c b/drivers/mtd/spi-nor/macronix.c
index c267cbcc7f1d..c9b9536f93f2 100644
--- a/drivers/mtd/spi-nor/macronix.c
+++ b/drivers/mtd/spi-nor/macronix.c
@@ -8,6 +8,128 @@

#include "core.h"

+#define MACRONIX_NOR_OP_WRITE_CR2 0x72 /* Write Configuration Register 2 */
+#define MACRONIX_NOR_OP_DTR_RD 0xee /* Octa DTR Read Opcode */
+
+#define MACRONIX_NOR_REG_CR2_MODE_ADDR 0 /* Address of Mode Enable in CR2 */
+#define MACRONIX_NOR_REG_CR2_DTR_OPI_ENABLE BIT(1) /* DTR OPI Enable */
+#define MACRONIX_NOR_REG_CR2_SPI 0 /* SPI Enable */
+
+/* Macronix SPI NOR flash operations. */
+#define MACRONIX_NOR_WRITE_CR2_OP(addr, buf, ndata) \
+ SPI_MEM_OP(SPI_MEM_OP_CMD(MACRONIX_NOR_OP_WRITE_CR2, 0), \
+ SPI_MEM_OP_ADDR(4, addr, 0), \
+ SPI_MEM_OP_NO_DUMMY, \
+ SPI_MEM_OP_DATA_OUT(ndata, buf, 0))
+
+static int macronix_nor_write_cr2(struct spi_nor *nor, u64 addr, u8 val)
+{
+ u8 *buf = nor->bouncebuf;
+ struct spi_mem_op op;
+ unsigned int nbytes;
+ int ret;
+
+ if (spi_nor_protocol_is_dtr(nor->reg_proto)) {
+ /*
+ * When the flash is configured in 8D-8D-8D mode, halfwords are
+ * send/received instead of bytes. One byte transactions are not
+ * allowed in 8D-8D-8D mode, so we're going to send two bytes to
+ * the flash to pass the 8D-8D-8D sanity checks. Macronix
+ * ignores the second byte value in case of a one byte register
+ * writes, we don't care of the value of the second byte.
+ * When in 8D-8D-8D mode endianness must be configured according
+ * to the flash requirements. Macronix swaps data bytes on a
+ * 16-bit boundary, so the SPI NOR subsystem instructs the SPI
+ * controllers to swap the bytes back to keep compatibility with
+ * the STR modes. The swap back is always done regardless if
+ * it's a register or data access. Since Macronix ignores the
+ * second byte value on register writes and the SPI controllers
+ * will swap the bytes, we actually have to set the value on the
+ * second byte and ignore the first.
+ */
+ buf[1] = val;
+ nbytes = 2;
+
+ } else {
+ buf[0] = val;
+ nbytes = 1;
+ }
+
+ op = (struct spi_mem_op)MACRONIX_NOR_WRITE_CR2_OP(addr, buf, nbytes);
+ spi_nor_spimem_setup_op(nor, &op, nor->reg_proto);
+ ret = spi_nor_write_enable(nor);
+ if (ret)
+ return ret;
+ return spi_mem_exec_op(nor->spimem, &op);
+}
+
+static int macronix_nor_octal_dtr_en(struct spi_nor *nor)
+{
+ u8 *buf = nor->bouncebuf;
+ int i, ret;
+
+ ret = macronix_nor_write_cr2(nor, MACRONIX_NOR_REG_CR2_MODE_ADDR,
+ MACRONIX_NOR_REG_CR2_DTR_OPI_ENABLE);
+ if (ret)
+ return ret;
+
+ /* Read flash ID to make sure the switch was successful. */
+ ret = spi_nor_read_id(nor, 4, 4, buf, SNOR_PROTO_8_8_8_DTR);
+ if (ret)
+ return ret;
+
+ for (i = 0; i < nor->info->id_len; i++)
+ if (buf[i * 2] != nor->info->id[i])
+ return -EINVAL;
+ return 0;
+}
+
+static int macronix_nor_octal_dtr_dis(struct spi_nor *nor)
+{
+ u8 *buf = nor->bouncebuf;
+ int ret;
+
+ ret = macronix_nor_write_cr2(nor, MACRONIX_NOR_REG_CR2_MODE_ADDR,
+ MACRONIX_NOR_REG_CR2_SPI);
+ if (ret)
+ return ret;
+
+ ret = spi_nor_read_id(nor, 0, 0, buf, SNOR_PROTO_1_1_1);
+ if (ret)
+ return ret;
+
+ if (memcmp(buf, nor->info->id, nor->info->id_len)) {
+ dev_dbg(nor->dev, "Failed to disable 8D-8D-8D mode.\n");
+ return -EINVAL;
+ }
+ return 0;
+}
+
+static int macronix_nor_octal_dtr_enable(struct spi_nor *nor, bool enable)
+{
+ return enable ? macronix_nor_octal_dtr_en(nor) :
+ macronix_nor_octal_dtr_dis(nor);
+}
+
+static void mx66lm1g45g_late_init(struct spi_nor *nor)
+{
+ nor->params->octal_dtr_enable = macronix_nor_octal_dtr_enable;
+
+ /* Set the Fast Read settings. */
+ nor->params->hwcaps.mask |= SNOR_HWCAPS_READ_8_8_8_DTR;
+ spi_nor_set_read_settings(&nor->params->reads[SNOR_CMD_READ_8_8_8_DTR],
+ 0, 20, MACRONIX_NOR_OP_DTR_RD,
+ SNOR_PROTO_8_8_8_DTR);
+
+ nor->cmd_ext_type = SPI_NOR_EXT_INVERT;
+ nor->params->rdsr_dummy = 4;
+ nor->params->rdsr_addr_nbytes = 4;
+}
+
+static struct spi_nor_fixups mx66lm1g45g_fixups = {
+ .late_init = mx66lm1g45g_late_init,
+};
+
static int
mx25l25635_post_bfpt_fixups(struct spi_nor *nor,
const struct sfdp_parameter_header *bfpt_header,
@@ -100,6 +222,14 @@ static const struct flash_info macronix_nor_parts[] = {
{ "mx66u2g45g", INFO(0xc2253c, 0, 64 * 1024, 4096)
NO_SFDP_FLAGS(SECT_4K | SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ)
FIXUP_FLAGS(SPI_NOR_4B_OPCODES) },
+ { "mx66lm1g45g", INFO(0xc2853b, 0, 64 * 1024, 2048)
+ NO_SFDP_FLAGS(SPI_NOR_SKIP_SFDP | SECT_4K |
+ SPI_NOR_OCTAL_DTR_READ | SPI_NOR_OCTAL_DTR_PP |
+ SPI_NOR_DTR_SWAB16)
+ FIXUP_FLAGS(SPI_NOR_4B_OPCODES | SPI_NOR_IO_MODE_EN_VOLATILE |
+ SPI_NOR_SOFT_RESET)
+ .fixups = &mx66lm1g45g_fixups,
+ },
};

static void macronix_nor_default_init(struct spi_nor *nor)
--
2.25.1