On Mon, Dec 12, 2022 at 06:07:22PM +0000, Sudip Mukherjee wrote:
> If the DW_SPI_CAP_EMODE capability is enabled then dw_spi_exec_enh_mem_op()
> will be used as the new enhanced mem_op. Lets initialize the buffer and
> get the pointers to receive and transmit data buffers.
> 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 | 53 ++++++++++++++++++++++++++++++++++++---
> 1 file changed, 50 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/spi/spi-dw-core.c b/drivers/spi/spi-dw-core.c
> index 49fad58ceb94a..89438ae2df17d 100644
> --- a/drivers/spi/spi-dw-core.c
> +++ b/drivers/spi/spi-dw-core.c
> @@ -798,6 +798,51 @@ static int dw_spi_exec_mem_op(struct spi_mem *mem, const struct spi_mem_op *op)
> return ret;
> }
>
> +static void dw_spi_init_enh_mem_buf(struct dw_spi *dws, const struct spi_mem_op *op)
> +{
> + unsigned int i, j;
> + u8 *out;
> +
> + out = dws->buf;
> + for (i = 0; i < DW_SPI_BUF_SIZE; ++i)
> + out[i] = 0;
> +
> + for (i = 0, j = op->cmd.nbytes; i < op->cmd.nbytes; ++i, --j)
> + out[i] = DW_SPI_GET_BYTE(op->cmd.opcode, op->cmd.nbytes - j);
> +
> + for (j = op->addr.nbytes, i = dws->reg_io_width; j > 0; ++i, --j)
> + out[i] = DW_SPI_GET_BYTE(op->addr.val, op->addr.nbytes - j);
In case of the non-eSPI implementation the outbound data consolidation
was required to get the most optimal loop of data transfer. In this
case I don't see it was required since the clock stretching feature is
available and the IRQ-based xfer procedure is implemented. Do I miss
something?
-Serge(y)
> +
> + dws->n_bytes = 1;
> + if (op->data.dir == SPI_MEM_DATA_IN) {
> + dws->rx = op->data.buf.in;
> + dws->rx_len = op->data.nbytes;
> + dws->tx = NULL;
> + dws->tx_len = 0;
> + } else if (op->data.dir == SPI_MEM_DATA_OUT) {
> + dws->tx_len = op->data.nbytes;
> + dws->tx = (void *)op->data.buf.out;
> + dws->rx = NULL;
> + dws->rx_len = 0;
> + } else {
> + dws->rx = NULL;
> + dws->rx_len = 0;
> + dws->tx = NULL;
> + dws->tx_len = 0;
> + }
> +}
> +
> +static int dw_spi_exec_enh_mem_op(struct spi_mem *mem, const struct spi_mem_op *op)
> +{
> + struct spi_controller *ctlr = mem->spi->controller;
> + struct dw_spi *dws = spi_controller_get_devdata(ctlr);
> +
> + /* Collect cmd and addr into a single buffer */
> + dw_spi_init_enh_mem_buf(dws, op);
> +
> + return 0;
> +}
> +
> /*
> * Initialize the default memory operations if a glue layer hasn't specified
> * custom ones. Direct mapping operations will be preserved anyway since DW SPI
> @@ -812,11 +857,13 @@ 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;
> - if (dws->caps & DW_SPI_CAP_EMODE)
> + if (dws->caps & DW_SPI_CAP_EMODE) {
> + dws->mem_ops.exec_op = dw_spi_exec_enh_mem_op;
> dws->mem_ops.supports_op = dw_spi_supports_enh_mem_op;
> - else
> + } else {
> + dws->mem_ops.exec_op = dw_spi_exec_mem_op;
> 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;
> }
> --
> 2.30.2
>
