spi: atmel-quadspi: Fix AHB memory accesses

Following error was seen when mounting a 16MByte ubifs:
UBIFS error (ubi0:0 pid 1893): check_lpt_type.constprop.6: invalid type (15) in LPT node type

QSPI_IFR.TFRTYP was not set correctly. When data transfer is enabled
and one wants to access the serial memory through AHB in order to:
 - read in the serial memory, but not a memory data, for example
   a JEDEC-ID, QSPI_IFR.TFRTYP must be written to '0' (both sama5d2
   and sam9x60).
 - read in the serial memory, and particularly a memory data,
   TFRTYP must be written to '1' (both sama5d2 and sam9x60).
 - write in the serial memory, but not a memory data, for example
   writing the configuration or the QSPI_SR, TFRTYP must be written
   to '2' for sama5d2 and to '0' for sam9x60.
 - write in the serial memory in particular to program a memory data,
   TFRTYP must be written to '3' for sama5d2 and to '1' for sam9x60.

Fix the setting of the QSPI_IFR.TFRTYP field.

Fixes: 2d30ac5e ("mtd: spi-nor: atmel-quadspi: Use spi-mem interface for atmel-quadspi driver")
Cc: <stable@vger.kernel.org> # v5.0+
Reported-by: Tom Burkart <tom@aussec.com>
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Link: https://lore.kernel.org/r/20201207135959.154124-2-tudor.ambarus@microchip.comSigned-off-by: Mark Brown <broonie@kernel.org>

drivers/spi/atmel-quadspi.c

@@ -365,10 +365,14 @@ static int atmel_qspi_set_cfg(struct atmel_qspi *aq,
 	if (dummy_cycles)
 		ifr |= QSPI_IFR_NBDUM(dummy_cycles);
 
-	/* Set data enable */
-	if (op->data.nbytes)
+	/* Set data enable and data transfer type. */
+	if (op->data.nbytes) {
 		ifr |= QSPI_IFR_DATAEN;
 
+		if (op->addr.nbytes)
+			ifr |= QSPI_IFR_TFRTYP_MEM;
+	}
+
 	/*
 	 * If the QSPI controller is set in regular SPI mode, set it in
 	 * Serial Memory Mode (SMM).
@@ -393,7 +397,7 @@ static int atmel_qspi_set_cfg(struct atmel_qspi *aq,
 			atmel_qspi_write(icr, aq, QSPI_WICR);
 		atmel_qspi_write(ifr, aq, QSPI_IFR);
 	} else {
-		if (op->data.dir == SPI_MEM_DATA_OUT)
+		if (op->data.nbytes && op->data.dir == SPI_MEM_DATA_OUT)
 			ifr |= QSPI_IFR_SAMA5D2_WRITE_TRSFR;
 
 		/* Set QSPI Instruction Frame registers */