spi: mxic: Create a helper to ease the start of an operation

Create the mxic_spi_mem_prep_op_cfg() helper to provide the content to
write to the register controlling the next IO command. This helper will
soon be used by the dirmap implementation and having this code
factorized out earlier will clarify this addition.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/linux-mtd/20220127091808.1043392-12-miquel.raynal@bootlin.com

drivers/spi/spi-mxic.c

@@ -296,6 +296,33 @@ static u32 mxic_spi_prep_hc_cfg(struct spi_device *spi, u32 flags)
 	       HC_CFG_SLV_ACT(spi->chip_select) | HC_CFG_IDLE_SIO_LVL(1);
 }
 
+static u32 mxic_spi_mem_prep_op_cfg(const struct spi_mem_op *op)
+{
+	u32 cfg = OP_CMD_BYTES(op->cmd.nbytes) |
+		  OP_CMD_BUSW(fls(op->cmd.buswidth) - 1) |
+		  (op->cmd.dtr ? OP_CMD_DDR : 0);
+
+	if (op->addr.nbytes)
+		cfg |= OP_ADDR_BYTES(op->addr.nbytes) |
+		       OP_ADDR_BUSW(fls(op->addr.buswidth) - 1) |
+		       (op->addr.dtr ? OP_ADDR_DDR : 0);
+
+	if (op->dummy.nbytes)
+		cfg |= OP_DUMMY_CYC(op->dummy.nbytes);
+
+	if (op->data.nbytes) {
+		cfg |= OP_DATA_BUSW(fls(op->data.buswidth) - 1) |
+		       (op->data.dtr ? OP_DATA_DDR : 0);
+		if (op->data.dir == SPI_MEM_DATA_IN) {
+			cfg |= OP_READ;
+			if (op->data.dtr)
+				cfg |= OP_DQS_EN;
+		}
+	}
+
+	return cfg;
+}
+
 static int mxic_spi_data_xfer(struct mxic_spi *mxic, const void *txbuf,
 			      void *rxbuf, unsigned int len)
 {
@@ -366,7 +393,6 @@ static int mxic_spi_mem_exec_op(struct spi_mem *mem,
 {
 	struct mxic_spi *mxic = spi_master_get_devdata(mem->spi->master);
 	int i, ret;
-	u32 ss_ctrl;
 	u8 addr[8], cmd[2];
 
 	ret = mxic_spi_set_freq(mxic, mem->spi->max_speed_hz);
@@ -378,29 +404,8 @@ static int mxic_spi_mem_exec_op(struct spi_mem *mem,
 
 	writel(HC_EN_BIT, mxic->regs + HC_EN);
 
-	ss_ctrl = OP_CMD_BYTES(op->cmd.nbytes) |
-		  OP_CMD_BUSW(fls(op->cmd.buswidth) - 1) |
-		  (op->cmd.dtr ? OP_CMD_DDR : 0);
-
-	if (op->addr.nbytes)
-		ss_ctrl |= OP_ADDR_BYTES(op->addr.nbytes) |
-			   OP_ADDR_BUSW(fls(op->addr.buswidth) - 1) |
-			   (op->addr.dtr ? OP_ADDR_DDR : 0);
-
-	if (op->dummy.nbytes)
-		ss_ctrl |= OP_DUMMY_CYC(op->dummy.nbytes);
-
-	if (op->data.nbytes) {
-		ss_ctrl |= OP_DATA_BUSW(fls(op->data.buswidth) - 1) |
-			   (op->data.dtr ? OP_DATA_DDR : 0);
-		if (op->data.dir == SPI_MEM_DATA_IN) {
-			ss_ctrl |= OP_READ;
-			if (op->data.dtr)
-				ss_ctrl |= OP_DQS_EN;
-		}
-	}
-
-	writel(ss_ctrl, mxic->regs + SS_CTRL(mem->spi->chip_select));
+	writel(mxic_spi_mem_prep_op_cfg(op),
+	       mxic->regs + SS_CTRL(mem->spi->chip_select));
 
 	writel(readl(mxic->regs + HC_CFG) | HC_CFG_MAN_CS_ASSERT,
 	       mxic->regs + HC_CFG);