[PATCH 2/2] mtd: spi-nor: issi: Add in support for IS25LX256 chip, operating in Octal STR mode

From: Nathan Barrett-Morrison
Date: Wed Nov 23 2022 - 16:14:07 EST


Adds the is25lx256 entry to the nor_parts table along with the
additional STR enablement fixups and logic

Signed-off-by: Nathan Barrett-Morrison <nathan.morrison@xxxxxxxxxxx>
---
drivers/mtd/spi-nor/issi.c | 101 +++++++++++++++++++++++++++++++++++++
1 file changed, 101 insertions(+)

diff --git a/drivers/mtd/spi-nor/issi.c b/drivers/mtd/spi-nor/issi.c
index 89a66a19d754..89f3cdd51075 100644
--- a/drivers/mtd/spi-nor/issi.c
+++ b/drivers/mtd/spi-nor/issi.c
@@ -8,6 +8,15 @@

#include "core.h"

+#define SPINOR_OP_STR_RD 0x8B /* Fast Read opcode in DTR mode */
+#define SPINOR_OP_STR_PP 0x82 /* Octal Input Fast Program */
+#define SPINOR_OP_RD_ANY_REG 0x85 /* Read volatile register */
+#define SPINOR_OP_WR_ANY_REG 0x81 /* Write volatile register */
+#define SPINOR_REG_CFR0V 0x00 /* For setting octal DTR mode */
+#define SPINOR_REG_CFR1V 0x01 /* For setting dummy cycles */
+#define SPINOR_OCT_STR 0xc7 /* Enable Octal DTR. */
+#define SPINOR_EXSPI 0xff /* Enable Extended SPI (default) */
+
static int
is25lp256_post_bfpt_fixups(struct spi_nor *nor,
const struct sfdp_parameter_header *bfpt_header,
@@ -29,6 +38,94 @@ static const struct spi_nor_fixups is25lp256_fixups = {
.post_bfpt = is25lp256_post_bfpt_fixups,
};

+static int spi_nor_issi_octal_str_enable(struct spi_nor *nor, bool enable)
+{
+ struct spi_mem_op op;
+ u8 *buf = nor->bouncebuf;
+ int ret;
+
+ ret = spi_nor_write_enable(nor);
+ if (ret)
+ return ret;
+
+ if (enable)
+ *buf = SPINOR_OCT_STR;
+ else
+ *buf = SPINOR_EXSPI;
+
+ op = (struct spi_mem_op)
+ SPI_MEM_OP(SPI_MEM_OP_CMD(SPINOR_OP_WR_ANY_REG, 1),
+ SPI_MEM_OP_ADDR(enable ? 3 : 4,
+ SPINOR_REG_CFR0V, 1),
+ SPI_MEM_OP_NO_DUMMY,
+ SPI_MEM_OP_DATA_OUT(1, buf, 1));
+
+ if (!enable)
+ spi_nor_spimem_setup_op(nor, &op, SNOR_PROTO_1_1_8);
+ else
+ spi_nor_spimem_setup_op(nor, &op, SNOR_PROTO_1_1_1);
+
+
+ ret = spi_mem_exec_op(nor->spimem, &op);
+ if (ret)
+ return ret;
+
+
+ /* Read flash ID to make sure the switch was successful. */
+ op = (struct spi_mem_op)
+ SPI_MEM_OP(SPI_MEM_OP_CMD(SPINOR_OP_RDID, 1),
+ SPI_MEM_OP_NO_ADDR,
+ SPI_MEM_OP_NO_DUMMY,
+ SPI_MEM_OP_DATA_IN(round_up(nor->info->id_len, 2),
+ buf, 1));
+
+ if (enable)
+ spi_nor_spimem_setup_op(nor, &op, SNOR_PROTO_1_1_8);
+ else
+ spi_nor_spimem_setup_op(nor, &op, SNOR_PROTO_1_1_1);
+
+
+ ret = spi_mem_exec_op(nor->spimem, &op);
+ if (ret)
+ return ret;
+
+ if (memcmp(buf, nor->info->id, nor->info->id_len))
+ return -EINVAL;
+
+ return 0;
+}
+
+static void is25lx256_default_init(struct spi_nor *nor)
+{
+ nor->params->octal_str_enable = spi_nor_issi_octal_str_enable;
+}
+
+static void is25lx256_post_sfdp_fixup(struct spi_nor *nor)
+{
+ /* Fixup read command to 8 dummy cycles, 1S-1S-8S */
+ nor->params->hwcaps.mask |= SNOR_HWCAPS_READ_8_8_8;
+ spi_nor_set_read_settings(&nor->params->reads[SNOR_CMD_READ_8_8_8],
+ 0, 8, SPINOR_OP_STR_RD,
+ SNOR_PROTO_1_1_8);
+
+ /* Fixup page program command to 1S-1S-8S */
+ nor->params->hwcaps.mask |= SNOR_HWCAPS_PP_8_8_8;
+ spi_nor_set_pp_settings(&nor->params->page_programs[SNOR_CMD_PP_8_8_8],
+ SPINOR_OP_STR_PP, SNOR_PROTO_1_1_8);
+
+ /*
+ * 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.
+ */
+ nor->params->quad_enable = NULL;
+}
+
+static struct spi_nor_fixups is25lx256_fixups = {
+ .default_init = is25lx256_default_init,
+ .post_sfdp = is25lx256_post_sfdp_fixup,
+};
+
static void pm25lv_nor_late_init(struct spi_nor *nor)
{
struct spi_nor_erase_map *map = &nor->params->erase_map;
@@ -74,6 +171,10 @@ static const struct flash_info issi_nor_parts[] = {
NO_SFDP_FLAGS(SECT_4K | SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ)
FIXUP_FLAGS(SPI_NOR_4B_OPCODES)
.fixups = &is25lp256_fixups },
+ { "is25lx256", INFO(0x9d5a19, 0, 128 * 1024, 256)
+ NO_SFDP_FLAGS(SECT_4K | SPI_NOR_OCTAL_STR_PP | SPI_NOR_OCTAL_STR_READ)
+ FIXUP_FLAGS(SPI_NOR_4B_OPCODES | SPI_NOR_IO_MODE_EN_VOLATILE)
+ .fixups = &is25lx256_fixups },

/* PMC */
{ "pm25lv512", INFO(0, 0, 32 * 1024, 2)
--
2.30.2