[PATCH v4 08/11] mtd: spi-nor: spansion: Rework spi_nor_cypress_octal_dtr_enable()

Tudor Ambarus
2022-04-20T10:36:01Z

Introduce template operation to remove code duplication.
Split spi_nor_cypress_octal_dtr_enable() in
spi_nor_cypress_octal_dtr_ena() spi_nor_cypress_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 read.
Add debug 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/spansion.c | 128 ++++++++++++++++++---------------
1 file changed, 69 insertions(+), 59 deletions(-)

diff --git a/drivers/mtd/spi-nor/spansion.c b/drivers/mtd/spi-nor/spansion.c
index c5988312cc91..56b43074ef17 100644
--- a/drivers/mtd/spi-nor/spansion.c
+++ b/drivers/mtd/spi-nor/spansion.c
@@ -23,87 +23,81 @@
#define SPINOR_REG_CYPRESS_CFR5V_OCT_DTR_DS 0
#define SPINOR_OP_CYPRESS_RD_FAST 0xee

-/**
- * cypress_nor_octal_dtr_enable() - Enable octal DTR on Cypress flashes.
- * @nor: pointer to a 'struct spi_nor'
- * @enable: whether to enable or disable Octal DTR
- *
- * This also sets the memory access latency cycles to 24 to allow the flash to
- * run at up to 200MHz.
- *
- * Return: 0 on success, -errno otherwise.
- */
-static int cypress_nor_octal_dtr_enable(struct spi_nor *nor, bool enable)
+/* Cypress SPI NOR flash operations. */
+#define CYPRESS_NOR_WR_ANY_REG_OP(naddr, addr, ndata, buf) \
+ SPI_MEM_OP(SPI_MEM_OP_CMD(SPINOR_OP_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 cypress_nor_octal_dtr_en(struct spi_nor *nor)
{
struct spi_mem_op op;
u8 *buf = nor->bouncebuf;
int ret;

- if (enable) {
- /* Use 24 dummy cycles for memory array reads. */
- ret = spi_nor_write_enable(nor);
- if (ret)
- return ret;
+ /* Use 24 dummy cycles for memory array reads. */
+ *buf = SPINOR_REG_CYPRESS_CFR2V_MEMLAT_11_24;
+ op = (struct spi_mem_op)
+ CYPRESS_NOR_WR_ANY_REG_OP(3, SPINOR_REG_CYPRESS_CFR2V, 1, buf);

- *buf = SPINOR_REG_CYPRESS_CFR2V_MEMLAT_11_24;
- op = (struct spi_mem_op)
- SPI_MEM_OP(SPI_MEM_OP_CMD(SPINOR_OP_WR_ANY_REG, 1),
- SPI_MEM_OP_ADDR(3, SPINOR_REG_CYPRESS_CFR2V,
- 1),
- SPI_MEM_OP_NO_DUMMY,
- SPI_MEM_OP_DATA_OUT(1, buf, 1));
+ ret = spi_nor_write_any_volatile_reg(nor, &op, nor->reg_proto);
+ if (ret)
+ return ret;

- ret = spi_mem_exec_op(nor->spimem, &op);
- if (ret)
- return ret;
+ ret = spi_nor_wait_till_ready(nor);
+ if (ret)
+ return ret;

- ret = spi_nor_wait_till_ready(nor);
- if (ret)
- return ret;
+ nor->read_dummy = 24;

- nor->read_dummy = 24;
- }
+ /* Set the octal and DTR enable bits. */
+ buf[0] = SPINOR_REG_CYPRESS_CFR5V_OCT_DTR_EN;
+ op = (struct spi_mem_op)
+ CYPRESS_NOR_WR_ANY_REG_OP(3, SPINOR_REG_CYPRESS_CFR5V, 1, buf);

- /* Set/unset the octal and DTR enable bits. */
- ret = spi_nor_write_enable(nor);
+ ret = spi_nor_write_any_volatile_reg(nor, &op, nor->reg_proto);
if (ret)
return ret;

- if (enable) {
- buf[0] = SPINOR_REG_CYPRESS_CFR5V_OCT_DTR_EN;
- } else {
- /*
- * The register is 1-byte wide, but 1-byte transactions are not
- * allowed in 8D-8D-8D mode. Since there is no register at the
- * next location, just initialize the value to 0 and let the
- * transaction go on.
- */
- buf[0] = SPINOR_REG_CYPRESS_CFR5V_OCT_DTR_DS;
- buf[1] = 0;
+ /* Read flash ID to make sure the switch was successful. */
+ ret = spi_nor_read_id(nor, 4, 3, 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_WR_ANY_REG, 1),
- SPI_MEM_OP_ADDR(enable ? 3 : 4,
- SPINOR_REG_CYPRESS_CFR5V,
- 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;
+}

- ret = spi_mem_exec_op(nor->spimem, &op);
+static int cypress_nor_octal_dtr_dis(struct spi_nor *nor)
+{
+ struct spi_mem_op op;
+ u8 *buf = nor->bouncebuf;
+ int ret;
+
+ /*
+ * The register is 1-byte wide, but 1-byte transactions are not allowed
+ * in 8D-8D-8D mode. Since there is no register at the next location,
+ * just initialize the value to 0 and let the transaction go on.
+ */
+ buf[0] = SPINOR_REG_CYPRESS_CFR5V_OCT_DTR_DS;
+ buf[1] = 0;
+ op = (struct spi_mem_op)
+ CYPRESS_NOR_WR_ANY_REG_OP(4, SPINOR_REG_CYPRESS_CFR5V, 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, 4, 3, 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;
@@ -111,6 +105,22 @@ static int cypress_nor_octal_dtr_enable(struct spi_nor *nor, bool enable)
return 0;
}

+/**
+ * cypress_nor_octal_dtr_enable() - Enable octal DTR on Cypress flashes.
+ * @nor: pointer to a 'struct spi_nor'
+ * @enable: whether to enable or disable Octal DTR
+ *
+ * This also sets the memory access latency cycles to 24 to allow the flash to
+ * run at up to 200MHz.
+ *
+ * Return: 0 on success, -errno otherwise.
+ */
+static int cypress_nor_octal_dtr_enable(struct spi_nor *nor, bool enable)
+{
+ return enable ? cypress_nor_octal_dtr_en(nor) :
+ cypress_nor_octal_dtr_dis(nor);
+}
+
static void s28hs512t_default_init(struct spi_nor *nor)
{
nor->params->octal_dtr_enable = cypress_nor_octal_dtr_enable;