On Mon, Dec 12, 2022 at 06:07:21PM +0000, Sudip Mukherjee wrote:
> Before doing the mem op, spi controller will be queried about the
> buswidths it supports. Add the dual/quad/octal if the controller
> has the DW_SPI_CAP_EMODE capability.
> The DW_SPI_CAP_EMODE capability will be enabled in a later patch.
>
> Signed-off-by: Sudip Mukherjee <sudip.mukherjee@xxxxxxxxxx>
> ---
> drivers/spi/spi-dw-core.c | 25 ++++++++++++++++++++++++-
> drivers/spi/spi-dw.h | 1 +
> 2 files changed, 25 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/spi/spi-dw-core.c b/drivers/spi/spi-dw-core.c
> index d59401f16c47a..49fad58ceb94a 100644
> --- a/drivers/spi/spi-dw-core.c
> +++ b/drivers/spi/spi-dw-core.c
> @@ -510,6 +510,26 @@ static int dw_spi_adjust_mem_op_size(struct spi_mem *mem, struct spi_mem_op *op)
> return 0;
> }
>
> +static bool dw_spi_supports_enh_mem_op(struct spi_mem *mem,
> + const struct spi_mem_op *op)
> +{
> + if (op->addr.nbytes != 0 && op->addr.buswidth != 1 &&
> + op->addr.buswidth != op->data.buswidth)
> + return false;
> +
> + if (op->cmd.buswidth != 1 && op->cmd.buswidth != op->addr.buswidth &&
> + op->cmd.buswidth != op->data.buswidth)
> + return false;
> +
> + if (op->dummy.nbytes != 0 && op->data.dir == SPI_MEM_DATA_OUT)
> + return false;
> +
> + if (op->dummy.nbytes != 0 && op->dummy.nbytes / op->dummy.buswidth > 4)
> + return false;
> +
> + return spi_mem_default_supports_op(mem, op);
> +}
> +
> static bool dw_spi_supports_mem_op(struct spi_mem *mem,
> const struct spi_mem_op *op)
> {
> @@ -792,7 +812,10 @@ static void dw_spi_init_mem_ops(struct dw_spi *dws)
> if (!dws->mem_ops.exec_op && !(dws->caps & DW_SPI_CAP_CS_OVERRIDE) &&
> !dws->set_cs) {
> dws->mem_ops.adjust_op_size = dw_spi_adjust_mem_op_size;
> - dws->mem_ops.supports_op = dw_spi_supports_mem_op;
Please see my comment to the cover letter. In order to have a more
readable method I'd suggest to convert it to something like this:
< dw_spi_init_mem_ops() {
< if (dws->mem_ops.exec_op || dws->caps & DW_SPI_CAP_CS_OVERRIDE ||
< dws->set_cs)
< return;
<
< if (dws->caps & DW_SPI_CAP_ENH_CLK_STR) {
< dws->mem_ops.adjust_op_size = dw_spi_enh_adjust_mem_op;
< dws->mem_ops.supports_op = dw_spi_enh_supports_mem_op;
< dws->mem_ops.exec_op = dw_spi_enh_exec_mem_op;
<
< return;
< }
<
< dws->mem_ops.adjust_op_size = dw_spi_adjust_mem_op_size;
< dws->mem_ops.supports_op = dw_spi_supports_mem_op;
< dws->mem_ops.exec_op = dw_spi_exec_mem_op;
<
< return;
< }
> + if (dws->caps & DW_SPI_CAP_EMODE)
Your implementation is working only if the clock-stretching feature is
available.
> + dws->mem_ops.supports_op = dw_spi_supports_enh_mem_op;
> + else
> + dws->mem_ops.supports_op = dw_spi_supports_mem_op;
> dws->mem_ops.exec_op = dw_spi_exec_mem_op;
> if (!dws->max_mem_freq)
> dws->max_mem_freq = dws->max_freq;
> diff --git a/drivers/spi/spi-dw.h b/drivers/spi/spi-dw.h
> index f29d89d05f34b..327d037bdb10e 100644
> --- a/drivers/spi/spi-dw.h
> +++ b/drivers/spi/spi-dw.h
> @@ -34,6 +34,7 @@
> /* DW SPI controller capabilities */
> #define DW_SPI_CAP_CS_OVERRIDE BIT(0)
> #define DW_SPI_CAP_DFS32 BIT(1)
> +#define DW_SPI_CAP_EMODE BIT(2)
As I suggested in the cover letter let's make it DW_SPI_CAP_ENH (any
better suggestion?). Then the clock-stretching capability flag will be
DW_SPI_CAP_ENH_CLK_STR.
-Serge(y)
>
> /* Register offsets (Generic for both DWC APB SSI and DWC SSI IP-cores) */
> #define DW_SPI_CTRLR0 0x00
> --
> 2.30.2
>
