[PATCH v2 1/2] spi: armada-3700: Fix failing commands with quad-SPI

[Miquel Raynal <miquel.raynal@xxxxxxxxxxxxxxxxxx>]

A3700 SPI controller datasheet states that only the first line (IO0) is
used to receive and send instructions, addresses and dummy bytes,
unless for addresses during an RX operation in a quad SPI configuration
(see p.821 of the Armada-3720-DB datasheet). Otherwise, some commands
such as SPI NOR commands like READ_FROM_CACHE_DUAL_IO(0xeb) and
READ_FROM_CACHE_DUAL_IO(0xbb) will fail because these commands must send
address bytes through the four pins. Data transfer always use the four
bytes with this setup.

Thus, in quad SPI configuration, the A3700_SPI_ADDR_PIN bit must be set
only in this case to inform the controller that it must use the number
of pins indicated in the {A3700_SPI_DATA_PIN1,A3700_SPI_DATA_PIN0} field
during the address cycles of an RX operation.

Suggested-by: Ken Ma <make@xxxxxxxxxxx>
Signed-off-by: Miquel Raynal <miquel.raynal@xxxxxxxxxxxxxxxxxx>
---
 drivers/spi/spi-armada-3700.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/spi/spi-armada-3700.c b/drivers/spi/spi-armada-3700.c
index 6c7d7a460689..a28702b1fa05 100644
--- a/drivers/spi/spi-armada-3700.c
+++ b/drivers/spi/spi-armada-3700.c
@@ -161,7 +161,7 @@ static void a3700_spi_deactivate_cs(struct a3700_spi *a3700_spi,
 }
 
 static int a3700_spi_pin_mode_set(struct a3700_spi *a3700_spi,
-				  unsigned int pin_mode)
+				  unsigned int pin_mode, bool receiving)
 {
 	u32 val;
 
@@ -177,6 +177,9 @@ static int a3700_spi_pin_mode_set(struct a3700_spi *a3700_spi,
 		break;
 	case SPI_NBITS_QUAD:
 		val |= A3700_SPI_DATA_PIN1;
+		/* RX during address reception uses 4-pin */
+		if (receiving)
+			val |= A3700_SPI_ADDR_PIN;
 		break;
 	default:
 		dev_err(&a3700_spi->master->dev, "wrong pin mode %u", pin_mode);
@@ -653,7 +656,7 @@ static int a3700_spi_transfer_one(struct spi_master *master,
 	else if (xfer->rx_buf)
 		nbits = xfer->rx_nbits;
 
-	a3700_spi_pin_mode_set(a3700_spi, nbits);
+	a3700_spi_pin_mode_set(a3700_spi, nbits, xfer->rx_buf ? true : false);
 
 	if (xfer->rx_buf) {
 		/* Set read data length */
-- 
2.11.0

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