Re: [PATCH v2 2/9] spi: stm32: Add OSPI driver

[Mark Brown]

On Tue, Jan 28, 2025 at 09:17:24AM +0100, patrice.chotard@xxxxxxxxxxx wrote:

> +static int stm32_ospi_tx_poll(struct stm32_ospi *ospi, u8 *buf, u32 len, bool read)
> +{

> +	if (read)
> +		tx_fifo = stm32_ospi_read_fifo;
> +	else
> +		tx_fifo = stm32_ospi_write_fifo;

> +		tx_fifo(buf++, regs_base + OSPI_DR);

It feels like the _tx_poll and tx_fifo naming is a landmine waiting to
surprise people in the future.  The code sharing makes sense but the
naming is just looking to cause surprises, especially with it just being
a bool selecting read or write.

> +static int stm32_ospi_tx(struct stm32_ospi *ospi, const struct spi_mem_op *op)
> +{

> +       return stm32_ospi_tx_poll(ospi, buf, op->data.nbytes,
> +                                op->data.dir == SPI_MEM_DATA_IN);

Though the one caller is also using _tx only naming, it's a bit more
tied in with the op sending though.

> +	ctrl->mode_bits = SPI_RX_DUAL | SPI_RX_QUAD |
> +			  SPI_TX_DUAL | SPI_TX_QUAD |
> +			  SPI_TX_OCTAL | SPI_RX_OCTAL;
> +	ctrl->setup = stm32_ospi_setup;
> +	ctrl->bus_num = -1;
> +	ctrl->mem_ops = &stm32_ospi_mem_ops;
> +	ctrl->use_gpio_descriptors = true;
> +	ctrl->transfer_one_message = stm32_ospi_transfer_one_message;
> +	ctrl->num_chipselect = STM32_OSPI_MAX_NORCHIP;
> +	ctrl->dev.of_node = dev->of_node;

It looks like the controller only does half duplex as well so it should
set SPI_CONTROLLER_HALF_DUPLEX.

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