On Tue, 7 Aug 2018 07:06:58 +0200 Stefan Roese sr@denx.de wrote:
Hi Boris,
On 06.08.2018 21:53, Boris Brezillon wrote:
Hi Stefan,
On Mon, 6 Aug 2018 17:12:50 +0200 Stefan Roese sr@denx.de wrote:
Some SPI controller might now support full-duplex SPI transfers. This option can be enabled to use half-duplex operation mode for such SPI controllers.
Signed-off-by: Stefan Roese sr@denx.de Cc: Miquel Raynal miquel.raynal@bootlin.com Cc: Boris Brezillon boris.brezillon@bootlin.com Cc: Jagan Teki jagan@openedev.com
drivers/spi/Kconfig | 8 ++++++++ drivers/spi/spi-mem.c | 31 ++++++++++++++++++++++++++++--- 2 files changed, 36 insertions(+), 3 deletions(-)
diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig index 9fbd26740d..5bd8289284 100644 --- a/drivers/spi/Kconfig +++ b/drivers/spi/Kconfig @@ -25,6 +25,14 @@ config SPI_MEM This extension is meant to simplify interaction with SPI memories by providing an high-level interface to send memory-like commands.
+config SPI_MEM_HALF_DUPLEX
- bool "Use half-duplex SPI transfer"
- depends on SPI_MEM
- help
Some SPI controller might not support full-duplex SPI transfers.This option can be enabled to use half-duplex operation mode forsuch SPI controllers.- config ALTERA_SPI bool "Altera SPI driver" help
diff --git a/drivers/spi/spi-mem.c b/drivers/spi/spi-mem.c index 07ce799170..617fbbfe09 100644 --- a/drivers/spi/spi-mem.c +++ b/drivers/spi/spi-mem.c @@ -202,6 +202,10 @@ int spi_mem_exec_op(struct spi_slave *slave, const struct spi_mem_op *op) struct dm_spi_ops *ops = spi_get_ops(bus); unsigned int xfer_len, pos = 0; u8 *tx_buf, *rx_buf = NULL;
- unsigned int pos2;
- int tx_len;
- int rx_len;
- u32 flag; int ret; int i;
@@ -370,8 +374,29 @@ int spi_mem_exec_op(struct spi_slave *slave, const struct spi_mem_op *op) if (tx_data) memcpy(tx_buf + pos, op->data.buf.out, op->data.nbytes);
- ret = spi_xfer(slave, xfer_len * 8, tx_buf, rx_buf,
SPI_XFER_BEGIN | SPI_XFER_END);
- pos2 = pos;
- if (CONFIG_IS_ENABLED(SPI_MEM_HALF_DUPLEX)) {
if (rx_data) {tx_len = (sizeof(op->cmd.opcode) +op->addr.nbytes + op->dummy.nbytes);rx_len = op->data.nbytes;flag = SPI_XFER_BEGIN;pos2 = 0;} else {tx_len = xfer_len;rx_len = 0;flag = SPI_XFER_BEGIN | SPI_XFER_END;}ret = spi_xfer(slave, tx_len * 8, tx_buf, NULL, flag);if (rx_data) {ret = spi_xfer(slave, rx_len * 8, NULL,rx_buf, SPI_XFER_END);}Why not doing that all the time and split things in 3 transfers instead of 2:
1/ the opcode + address + dummy cycles 2/ the tx data 3/ the rx data (optional)
Actually it's:
1/ the opcode + address + dummy cycles 2/ tx or rx data (optional)
but I guess you figured this out already.