[PATCH] spi: rspi: Fix handling of QSPI code when transmit and receive

[Nguyen An Hoan <na-hoan@xxxxxxxxxxx>]

From: Hoan Nguyen An <na-hoan@xxxxxxxxxxx>

Process handling QSPI when transmit/receive at qspi_trigger_transfer_out_in() as follows:
Setting the trigger, is the number of bytes in the FIFO buffer to determine
when there is an interrupt. Then check if the value of triggering number is
32bits (4 bytes) or 1bytes, there will be corresponding processing
(if (n == QSPI_BUFFER_SIZE statement))
Handling (if (n == QSPI_BUFFER_SIZE) esle) this is unnecessary, we only need to
calculate triggering number to reduce the number of interrupts that occur
if the data is larger than 32 bits (4bytes), while the transfer to handle
that call to rspi_pio_transfer() is not necessary. The code will become
confusing and difficult to read.
The same with handling in qspi_transfer_out()/qspi_transfer_in().

Signed-off-by: Hoan Nguyen An <na-hoan@xxxxxxxxxxx>
---
 drivers/spi/spi-rspi.c | 71 ++++++++++++++++++++------------------------------
 1 file changed, 28 insertions(+), 43 deletions(-)

diff --git a/drivers/spi/spi-rspi.c b/drivers/spi/spi-rspi.c
index 3be8fbe..15f5723 100644
--- a/drivers/spi/spi-rspi.c
+++ b/drivers/spi/spi-rspi.c
@@ -739,27 +739,22 @@ static int qspi_trigger_transfer_out_in(struct rspi_data *rspi, const u8 *tx,
 	while (len > 0) {
 		n = qspi_set_send_trigger(rspi, len);
 		qspi_set_receive_trigger(rspi, len);
-		if (n == QSPI_BUFFER_SIZE) {
-			ret = rspi_wait_for_tx_empty(rspi);
-			if (ret < 0) {
-				dev_err(&rspi->ctlr->dev, "transmit timeout\n");
-				return ret;
-			}
-			for (i = 0; i < n; i++)
-				rspi_write_data(rspi, *tx++);
+		ret = rspi_wait_for_tx_empty(rspi);
+		if (ret < 0) {
+			dev_err(&rspi->ctlr->dev, "transmit timeout\n");
+			return ret;
+		}
+		for (i = 0; i < n; i++)
+			rspi_write_data(rspi, *tx++);
 
-			ret = rspi_wait_for_rx_full(rspi);
-			if (ret < 0) {
-				dev_err(&rspi->ctlr->dev, "receive timeout\n");
-				return ret;
-			}
-			for (i = 0; i < n; i++)
-				*rx++ = rspi_read_data(rspi);
-		} else {
-			ret = rspi_pio_transfer(rspi, tx, rx, n);
-			if (ret < 0)
-				return ret;
+		ret = rspi_wait_for_rx_full(rspi);
+		if (ret < 0) {
+			dev_err(&rspi->ctlr->dev, "receive timeout\n");
+			return ret;
 		}
+		for (i = 0; i < n; i++)
+			*rx++ = rspi_read_data(rspi);
+
 		len -= n;
 	}
 
@@ -796,19 +791,14 @@ static int qspi_transfer_out(struct rspi_data *rspi, struct spi_transfer *xfer)
 
 	while (n > 0) {
 		len = qspi_set_send_trigger(rspi, n);
-		if (len == QSPI_BUFFER_SIZE) {
-			ret = rspi_wait_for_tx_empty(rspi);
-			if (ret < 0) {
-				dev_err(&rspi->ctlr->dev, "transmit timeout\n");
-				return ret;
-			}
-			for (i = 0; i < len; i++)
-				rspi_write_data(rspi, *tx++);
-		} else {
-			ret = rspi_pio_transfer(rspi, tx, NULL, len);
-			if (ret < 0)
-				return ret;
+		ret = rspi_wait_for_tx_empty(rspi);
+		if (ret < 0) {
+			dev_err(&rspi->ctlr->dev, "transmit timeout\n");
+			return ret;
 		}
+		for (i = 0; i < len; i++)
+			rspi_write_data(rspi, *tx++);
+
 		n -= len;
 	}
 
@@ -833,19 +823,14 @@ static int qspi_transfer_in(struct rspi_data *rspi, struct spi_transfer *xfer)
 
 	while (n > 0) {
 		len = qspi_set_receive_trigger(rspi, n);
-		if (len == QSPI_BUFFER_SIZE) {
-			ret = rspi_wait_for_rx_full(rspi);
-			if (ret < 0) {
-				dev_err(&rspi->ctlr->dev, "receive timeout\n");
-				return ret;
-			}
-			for (i = 0; i < len; i++)
-				*rx++ = rspi_read_data(rspi);
-		} else {
-			ret = rspi_pio_transfer(rspi, NULL, rx, len);
-			if (ret < 0)
-				return ret;
+		ret = rspi_wait_for_rx_full(rspi);
+		if (ret < 0) {
+			dev_err(&rspi->ctlr->dev, "receive timeout\n");
+			return ret;
 		}
+		for (i = 0; i < len; i++)
+			*rx++ = rspi_read_data(rspi);
+
 		n -= len;
 	}
 
-- 
2.7.4