[PATCH v4 07/11] mtd: spi-nor: micron-st: Rework spi_nor_micron_octal_dtr_enable()

Tudor Ambarus
2022-04-20T10:35:56Z

Introduce template operation to remove code duplication.
Split spi_nor_micron_octal_dtr_enable() in spi_nor_micron_octal_dtr_en()
and spi_nor_micron_octal_dtr_dis() as it no longer made sense to try to
keep everything alltogether: too many "if (enable)" throughout the code,
which made the code difficult to follow. Add dev_dbg messages in case
spi_nor_read_id() fails.

Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Reviewed-by: Pratyush Yadav <p.yadav@ti.com>
Reviewed-by: Michael Walle <michael@walle.cc>
---
drivers/mtd/spi-nor/micron-st.c | 111 +++++++++++++++++---------------
1 file changed, 60 insertions(+), 51 deletions(-)

diff --git a/drivers/mtd/spi-nor/micron-st.c b/drivers/mtd/spi-nor/micron-st.c
index 41b87868ecf9..ce62e6be8fd2 100644
--- a/drivers/mtd/spi-nor/micron-st.c
+++ b/drivers/mtd/spi-nor/micron-st.c
@@ -28,75 +28,78 @@
#define FSR_P_ERR BIT(4) /* Program operation status */
#define FSR_PT_ERR BIT(1) /* Protection error bit */

-static int micron_st_nor_octal_dtr_enable(struct spi_nor *nor, bool enable)
+/* Micron ST SPI NOR flash operations. */
+#define MICRON_ST_NOR_WR_ANY_REG_OP(naddr, addr, ndata, buf) \
+ SPI_MEM_OP(SPI_MEM_OP_CMD(SPINOR_OP_MT_WR_ANY_REG, 0), \
+ SPI_MEM_OP_ADDR(naddr, addr, 0), \
+ SPI_MEM_OP_NO_DUMMY, \
+ SPI_MEM_OP_DATA_OUT(ndata, buf, 0))
+
+static int micron_st_nor_octal_dtr_en(struct spi_nor *nor)
{
struct spi_mem_op op;
u8 *buf = nor->bouncebuf;
int ret;

- if (enable) {
- /* Use 20 dummy cycles for memory array reads. */
- ret = spi_nor_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(3, SPINOR_REG_MT_CFR1V, 1),
- SPI_MEM_OP_NO_DUMMY,
- SPI_MEM_OP_DATA_OUT(1, buf, 1));
-
- ret = spi_mem_exec_op(nor->spimem, &op);
- if (ret)
- return ret;
-
- ret = spi_nor_wait_till_ready(nor);
- if (ret)
- return ret;
- }
+ /* Use 20 dummy cycles for memory array reads. */
+ *buf = 20;
+ op = (struct spi_mem_op)
+ MICRON_ST_NOR_WR_ANY_REG_OP(3, SPINOR_REG_MT_CFR1V, 1, buf);
+ ret = spi_nor_write_any_volatile_reg(nor, &op, nor->reg_proto);
+ if (ret)
+ return ret;
+ ret = spi_nor_wait_till_ready(nor);
+ if (ret)
+ return ret;

- ret = spi_nor_write_enable(nor);
+ buf[0] = SPINOR_MT_OCT_DTR;
+ op = (struct spi_mem_op)
+ MICRON_ST_NOR_WR_ANY_REG_OP(3, SPINOR_REG_MT_CFR0V, 1, buf);
+ ret = spi_nor_write_any_volatile_reg(nor, &op, nor->reg_proto);
if (ret)
return ret;

- if (enable) {
- buf[0] = SPINOR_MT_OCT_DTR;
- } else {
- /*
- * The register is 1-byte wide, but 1-byte transactions are not
- * allowed in 8D-8D-8D mode. The next register is the dummy
- * cycle configuration register. Since the transaction needs to
- * be at least 2 bytes wide, set the next register to its
- * default value. This also makes sense because the value was
- * changed when enabling 8D-8D-8D mode, it should be reset when
- * disabling.
- */
- buf[0] = SPINOR_MT_EXSPI;
- buf[1] = SPINOR_REG_MT_CFR1V_DEF;
+ /* Read flash ID to make sure the switch was successful. */
+ ret = spi_nor_read_id(nor, 0, 8, buf, SNOR_PROTO_8_8_8_DTR);
+ if (ret) {
+ dev_dbg(nor->dev, "error %d reading JEDEC ID after enabling 8D-8D-8D mode\n", ret);
+ return ret;
}

- op = (struct spi_mem_op)
- SPI_MEM_OP(SPI_MEM_OP_CMD(SPINOR_OP_MT_WR_ANY_REG, 1),
- SPI_MEM_OP_ADDR(enable ? 3 : 4,
- SPINOR_REG_MT_CFR0V, 1),
- SPI_MEM_OP_NO_DUMMY,
- SPI_MEM_OP_DATA_OUT(enable ? 1 : 2, buf, 1));
+ if (memcmp(buf, nor->info->id, nor->info->id_len))
+ return -EINVAL;

- if (!enable)
- spi_nor_spimem_setup_op(nor, &op, SNOR_PROTO_8_8_8_DTR);
+ return 0;
+}
+
+static int micron_st_nor_octal_dtr_dis(struct spi_nor *nor)
+{
+ struct spi_mem_op op;
+ u8 *buf = nor->bouncebuf;
+ int ret;

- ret = spi_mem_exec_op(nor->spimem, &op);
+ /*
+ * The register is 1-byte wide, but 1-byte transactions are not allowed
+ * in 8D-8D-8D mode. The next register is the dummy cycle configuration
+ * register. Since the transaction needs to be at least 2 bytes wide,
+ * set the next register to its default value. This also makes sense
+ * because the value was changed when enabling 8D-8D-8D mode, it should
+ * be reset when disabling.
+ */
+ buf[0] = SPINOR_MT_EXSPI;
+ buf[1] = SPINOR_REG_MT_CFR1V_DEF;
+ op = (struct spi_mem_op)
+ MICRON_ST_NOR_WR_ANY_REG_OP(4, SPINOR_REG_MT_CFR0V, 2, buf);
+ ret = spi_nor_write_any_volatile_reg(nor, &op, SNOR_PROTO_8_8_8_DTR);
if (ret)
return ret;

/* Read flash ID to make sure the switch was successful. */
- if (enable)
- ret = spi_nor_read_id(nor, 0, 8, buf, SNOR_PROTO_8_8_8_DTR);
- else
- ret = spi_nor_read_id(nor, 0, 0, buf, SNOR_PROTO_1_1_1);
- if (ret)
+ ret = spi_nor_read_id(nor, 0, 0, buf, SNOR_PROTO_1_1_1);
+ if (ret) {
+ dev_dbg(nor->dev, "error %d reading JEDEC ID after disabling 8D-8D-8D mode\n", ret);
return ret;
+ }

if (memcmp(buf, nor->info->id, nor->info->id_len))
return -EINVAL;
@@ -104,6 +107,12 @@ static int micron_st_nor_octal_dtr_enable(struct spi_nor *nor, bool enable)
return 0;
}

+static int micron_st_nor_octal_dtr_enable(struct spi_nor *nor, bool enable)
+{
+ return enable ? micron_st_nor_octal_dtr_en(nor) :
+ micron_st_nor_octal_dtr_dis(nor);
+}
+
static void mt35xu512aba_default_init(struct spi_nor *nor)
{
nor->params->octal_dtr_enable = micron_st_nor_octal_dtr_enable;