[PATCH v4 15/16] mtd: spi-nor: add support for Cypress Semper flash

Pratyush Yadav
2020-04-24T18:54:05Z

The Cypress Semper flash is an xSPI compliant octal DTR flash. Add
support for using it in octal DTR mode.

The flash by default boots in a hybrid sector mode. But the sector map
table on the part I had was programmed incorrectly and the SMPT values
on the flash don't match the public datasheet. Specifically, in some
places erase type 3 was used instead of 4. In addition, the region sizes
were incorrect in some places. So, for testing I set CFR3N[3] to enable
uniform sector sizes. Since the uniform sector mode bit is a
non-volatile bit, this series does not change it to avoid making any
permanent changes to the flash configuration. The correct data to
implement a fixup is not available right now and will be done in a
follow-up patch if needed.

Signed-off-by: Pratyush Yadav <p.yadav@ti.com>
---
drivers/mtd/spi-nor/spansion.c | 167 +++++++++++++++++++++++++++++++++
1 file changed, 167 insertions(+)

diff --git a/drivers/mtd/spi-nor/spansion.c b/drivers/mtd/spi-nor/spansion.c
index 88183eba8ac1..cc75134f579c 100644
--- a/drivers/mtd/spi-nor/spansion.c
+++ b/drivers/mtd/spi-nor/spansion.c
@@ -8,6 +8,168 @@

#include "core.h"

+/* For Cypress flash. */
+#define SPINOR_OP_RD_ANY_REG 0x65 /* Read any register */
+#define SPINOR_OP_WR_ANY_REG 0x71 /* Write any register */
+#define SPINOR_REG_CYPRESS_CFR2V 0x00800003
+#define SPINOR_REG_CYPRESS_CFR2V_MEMLAT_8_20 0x8
+#define SPINOR_REG_CYPRESS_CFR3V 0x00800004
+#define SPINOR_REG_CYPRESS_CFR3V_PGSZ BIT(4) /* Page size. */
+#define SPINOR_REG_CYPRESS_CFR4V 0x00800005
+#define SPINOR_REG_CYPRESS_CFR5V 0x00800006
+#define SPINOR_REG_CYPRESS_CFR5V_OCT_DTR_EN 0x3
+#define SPINOR_REG_CYPRESS_CFR5V_OCT_DTR_DS 0
+#define SPINOR_OP_CYPRESS_RD_FAST 0xee
+
+/**
+ * spi_nor_cypress_octal_enable() - Enable octal DTR mode on Cypress flashes.
+ * @nor: pointer to a 'struct spi_nor'
+ *
+ * This also sets the memory access latency cycles to 20, which is the default
+ * in the spi-nor framework.
+ *
+ * Return: 0 on success, -errno otherwise.
+ */
+static int spi_nor_cypress_octal_enable(struct spi_nor *nor, bool enable)
+{
+ struct spi_mem_op op;
+ u8 *buf = nor->bouncebuf;
+ u8 addr_width;
+ int ret;
+
+ if (enable)
+ addr_width = 3;
+ else
+ addr_width = 4;
+
+ if (enable) {
+ /* Use 20 dummy cycles for memory array reads. */
+ ret = spi_nor_write_enable(nor);
+ if (ret)
+ return ret;
+
+ *buf = SPINOR_REG_CYPRESS_CFR2V_MEMLAT_8_20;
+ op = (struct spi_mem_op)
+ SPI_MEM_OP(SPI_MEM_OP_CMD(SPINOR_OP_WR_ANY_REG, 1),
+ SPI_MEM_OP_ADDR(addr_width,
+ SPINOR_REG_CYPRESS_CFR2V,
+ 1),
+ SPI_MEM_OP_NO_DUMMY,
+ SPI_MEM_OP_DATA_OUT(1, buf, 1));
+ ret = spi_mem_exec_op(nor->spimem, &op);
+ if (ret) {
+ dev_warn(nor->dev,
+ "failed to set default memory latency value: %d\n",
+ ret);
+ return ret;
+ }
+ ret = spi_nor_wait_till_ready(nor);
+ if (ret)
+ return ret;
+
+ nor->read_dummy = 20;
+ }
+
+ /* Set/unset the octal and DTR enable bits. */
+ ret = spi_nor_write_enable(nor);
+ if (ret)
+ return ret;
+
+ if (enable)
+ *buf = SPINOR_REG_CYPRESS_CFR5V_OCT_DTR_EN;
+ else
+ *buf = SPINOR_REG_CYPRESS_CFR5V_OCT_DTR_DS;
+ op = (struct spi_mem_op)
+ SPI_MEM_OP(SPI_MEM_OP_CMD(SPINOR_OP_WR_ANY_REG, 1),
+ SPI_MEM_OP_ADDR(addr_width,
+ SPINOR_REG_CYPRESS_CFR5V,
+ 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_8_8_8_DTR);
+
+ ret = spi_mem_exec_op(nor->spimem, &op);
+ if (ret) {
+ dev_warn(nor->dev, "Failed to enable octal DTR mode\n");
+ return ret;
+ }
+
+ return 0;
+}
+
+static void s28hs512t_default_init(struct spi_nor *nor)
+{
+ nor->params->octal_dtr_enable = spi_nor_cypress_octal_enable;
+}
+
+static void s28hs512t_post_sfdp_fixup(struct spi_nor *nor)
+{
+ /*
+ * On older versions of the flash the xSPI Profile 1.0 table has the
+ * 8D-8D-8D Fast Read opcode as 0x00. But it actually should be 0xEE.
+ */
+ if (nor->params->reads[SNOR_CMD_READ_8_8_8_DTR].opcode == 0)
+ nor->params->reads[SNOR_CMD_READ_8_8_8_DTR].opcode =
+ SPINOR_OP_CYPRESS_RD_FAST;
+
+ /* This flash is also missing the 4-byte Page Program opcode bit. */
+ spi_nor_set_pp_settings(&nor->params->page_programs[SNOR_CMD_PP],
+ SPINOR_OP_PP_4B, SNOR_PROTO_1_1_1);
+ /*
+ * Since xSPI Page Program opcode is backward compatible with
+ * Legacy SPI, use Legacy SPI opcode there as well.
+ */
+ spi_nor_set_pp_settings(&nor->params->page_programs[SNOR_CMD_PP_8_8_8_DTR],
+ SPINOR_OP_PP_4B, SNOR_PROTO_8_8_8_DTR);
+
+ /*
+ * The xSPI Profile 1.0 table advertises the number of additional
+ * address bytes needed for Read Status Register command as 0 but the
+ * actual value for that is 4.
+ */
+ nor->params->rdsr_addr_nbytes = 4;
+}
+
+static int s28hs512t_post_bfpt_fixup(struct spi_nor *nor,
+ const struct sfdp_parameter_header *bfpt_header,
+ const struct sfdp_bfpt *bfpt,
+ struct spi_nor_flash_parameter *params)
+{
+ struct spi_mem_op op;
+ u8 *buf = nor->bouncebuf;
+ u8 addr_width = 3;
+ int ret;
+
+ /*
+ * The BFPT table advertises a 512B page size but the page size is
+ * actually configurable (with the default being 256B). Read from
+ * CFR3V[4] and set the correct size.
+ */
+ op = (struct spi_mem_op)
+ SPI_MEM_OP(SPI_MEM_OP_CMD(SPINOR_OP_RD_ANY_REG, 1),
+ SPI_MEM_OP_ADDR(addr_width, SPINOR_REG_CYPRESS_CFR3V, 1),
+ SPI_MEM_OP_NO_DUMMY,
+ SPI_MEM_OP_DATA_IN(1, buf, 1));
+ ret = spi_mem_exec_op(nor->spimem, &op);
+ if (ret)
+ return ret;
+
+ if (*buf & SPINOR_REG_CYPRESS_CFR3V_PGSZ)
+ params->page_size = 512;
+ else
+ params->page_size = 256;
+
+ return 0;
+}
+
+static struct spi_nor_fixups s28hs512t_fixups = {
+ .default_init = s28hs512t_default_init,
+ .post_sfdp = s28hs512t_post_sfdp_fixup,
+ .post_bfpt = s28hs512t_post_bfpt_fixup,
+};
+
static const struct flash_info spansion_parts[] = {
/* Spansion/Cypress -- single (large) sector size only, at least
* for the chips listed here (without boot sectors).
@@ -72,6 +234,11 @@ static const struct flash_info spansion_parts[] = {
{ "s25fl256l", INFO(0x016019, 0, 64 * 1024, 512,
SECT_4K | SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ |
SPI_NOR_4B_OPCODES) },
+ { "s28hs512t", INFO(0x345b1a, 0, 256 * 1024, 256,
+ SECT_4K | SPI_NOR_OCTAL_DTR_READ |
+ SPI_NOR_SOFT_RESET)
+ .fixups = &s28hs512t_fixups,
+ },
};

static void spansion_post_sfdp_fixups(struct spi_nor *nor)