[PATCH 1/2] spi: spi-mem: Enable DTR transfers using the standard API

[Miquel Raynal]

Most spi-mem operations today go through controllers implementing the
spi-mem API. But it is also totally possible to use any standard SPI
controller to operate these memories. If the controllers support DTR,
there is no reason to prevent this feature from being used.

Extend spi_mem_exec_op()'s fallback to the standard SPI API, by filling
the transfer DTR information. Doing so also requires checking the
dtr_caps flag, of course.

Signed-off-by: Miquel Raynal <miquel.raynal@xxxxxxxxxxx>
---
 drivers/spi/spi-mem.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/spi/spi-mem.c b/drivers/spi/spi-mem.c
index 5f973ebfb8b6..94d122be1c93 100644
--- a/drivers/spi/spi-mem.c
+++ b/drivers/spi/spi-mem.c
@@ -172,7 +172,7 @@ bool spi_mem_default_supports_op(struct spi_mem *mem,
 		op->cmd.dtr || op->addr.dtr || op->dummy.dtr || op->data.dtr;
 
 	if (op_is_dtr) {
-		if (!spi_mem_controller_is_capable(ctlr, dtr))
+		if (!spi_mem_controller_is_capable(ctlr, dtr) && !ctlr->dtr_caps)
 			return false;
 
 		if (op->data.swap16 && !spi_mem_controller_is_capable(ctlr, swap16))
@@ -461,6 +461,7 @@ int spi_mem_exec_op(struct spi_mem *mem, const struct spi_mem_op *op)
 	xfers[xferpos].len = op->cmd.nbytes;
 	xfers[xferpos].tx_nbits = op->cmd.buswidth;
 	xfers[xferpos].speed_hz = op->max_freq;
+	xfers[xferpos].dtr_mode = op->cmd.dtr;
 	spi_message_add_tail(&xfers[xferpos], &msg);
 	xferpos++;
 	totalxferlen++;
@@ -476,6 +477,7 @@ int spi_mem_exec_op(struct spi_mem *mem, const struct spi_mem_op *op)
 		xfers[xferpos].len = op->addr.nbytes;
 		xfers[xferpos].tx_nbits = op->addr.buswidth;
 		xfers[xferpos].speed_hz = op->max_freq;
+		xfers[xferpos].dtr_mode = op->addr.dtr;
 		spi_message_add_tail(&xfers[xferpos], &msg);
 		xferpos++;
 		totalxferlen += op->addr.nbytes;
@@ -488,6 +490,7 @@ int spi_mem_exec_op(struct spi_mem *mem, const struct spi_mem_op *op)
 		xfers[xferpos].tx_nbits = op->dummy.buswidth;
 		xfers[xferpos].dummy_data = 1;
 		xfers[xferpos].speed_hz = op->max_freq;
+		xfers[xferpos].dtr_mode = op->dummy.dtr;
 		spi_message_add_tail(&xfers[xferpos], &msg);
 		xferpos++;
 		totalxferlen += op->dummy.nbytes;
@@ -504,6 +507,7 @@ int spi_mem_exec_op(struct spi_mem *mem, const struct spi_mem_op *op)
 
 		xfers[xferpos].len = op->data.nbytes;
 		xfers[xferpos].speed_hz = op->max_freq;
+		xfers[xferpos].dtr_mode = op->data.dtr;
 		spi_message_add_tail(&xfers[xferpos], &msg);
 		xferpos++;
 		totalxferlen += op->data.nbytes;

-- 
2.54.0