spi: rspi: Factor out handling of common mode bits

Basic SPI features like clock phase/polarity and loopback mode are
common to all RSPI variants.  Factor them out to reduce duplication.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20200218105810.902-2-geert+renesas@glider.beSigned-off-by: Mark Brown <broonie@kernel.org>

drivers/spi/spi-rspi.c

@@ -239,7 +239,7 @@ struct spi_ops {
 	int (*set_config_register)(struct rspi_data *rspi, int access_size);
 	int (*transfer_one)(struct spi_controller *ctlr,
 			    struct spi_device *spi, struct spi_transfer *xfer);
-	u16 mode_bits;
+	u16 extra_mode_bits;
 	u16 flags;
 	u16 fifo_size;
 	u8 num_hw_ss;
@@ -1122,7 +1122,6 @@ static int rspi_remove(struct platform_device *pdev)
 static const struct spi_ops rspi_ops = {
 	.set_config_register =	rspi_set_config_register,
 	.transfer_one =		rspi_transfer_one,
-	.mode_bits =		SPI_CPHA | SPI_CPOL | SPI_LOOP,
 	.flags =		SPI_CONTROLLER_MUST_TX,
 	.fifo_size =		8,
 	.num_hw_ss =		2,
@@ -1131,7 +1130,6 @@ static const struct spi_ops rspi_ops = {
 static const struct spi_ops rspi_rz_ops = {
 	.set_config_register =	rspi_rz_set_config_register,
 	.transfer_one =		rspi_rz_transfer_one,
-	.mode_bits =		SPI_CPHA | SPI_CPOL | SPI_LOOP,
 	.flags =		SPI_CONTROLLER_MUST_RX | SPI_CONTROLLER_MUST_TX,
 	.fifo_size =		8,	/* 8 for TX, 32 for RX */
 	.num_hw_ss =		1,
@@ -1140,8 +1138,7 @@ static const struct spi_ops rspi_rz_ops = {
 static const struct spi_ops qspi_ops = {
 	.set_config_register =	qspi_set_config_register,
 	.transfer_one =		qspi_transfer_one,
-	.mode_bits =		SPI_CPHA | SPI_CPOL | SPI_LOOP |
-				SPI_TX_DUAL | SPI_TX_QUAD |
+	.extra_mode_bits =	SPI_TX_DUAL | SPI_TX_QUAD |
 				SPI_RX_DUAL | SPI_RX_QUAD,
 	.flags =		SPI_CONTROLLER_MUST_RX | SPI_CONTROLLER_MUST_TX,
 	.fifo_size =		32,
@@ -1258,7 +1255,7 @@ static int rspi_probe(struct platform_device *pdev)
 	ctlr->transfer_one = ops->transfer_one;
 	ctlr->prepare_message = rspi_prepare_message;
 	ctlr->unprepare_message = rspi_unprepare_message;
-	ctlr->mode_bits = ops->mode_bits;
+	ctlr->mode_bits = SPI_CPHA | SPI_CPOL | SPI_LOOP | ops->extra_mode_bits;
 	ctlr->flags = ops->flags;
 	ctlr->dev.of_node = pdev->dev.of_node;
 	ctlr->use_gpio_descriptors = true;