Re: [PATCH v3 8/9] mtd: spi-nor: spansion: Rework spi_nor_cypress_octal_dtr_enable()

Michael Walle
2022-04-19T12:56:25Z

Am 2022-04-11 11:10, schrieb Tudor Ambarus:
> 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>

> ---
> v3: collect R-b, update commit message, add dev_dbg message in case
> spi_nor_read_id() fails.
>
> 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..35d8edb515a3 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_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_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_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;

--
-michael