linux-kernel - [PATCH v2 2/4] spi: s3c64xx: prepare for a different flavor of iowrite rep

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Date: Wed,  7 Feb 2024 11:15:14 +0000
From: Tudor Ambarus <tudor.ambarus@...aro.org>
To: broonie@...nel.org,
	andi.shyti@...nel.org,
	semen.protsenko@...aro.org
Cc: krzysztof.kozlowski@...aro.org,
	alim.akhtar@...sung.com,
	linux-spi@...r.kernel.org,
	linux-samsung-soc@...r.kernel.org,
	linux-arm-kernel@...ts.infradead.org,
	linux-kernel@...r.kernel.org,
	andre.draszik@...aro.org,
	peter.griffin@...aro.org,
	kernel-team@...roid.com,
	willmcvicker@...gle.com,
	robh+dt@...nel.org,
	conor+dt@...nel.org,
	devicetree@...r.kernel.org,
	Tudor Ambarus <tudor.ambarus@...aro.org>
Subject: [PATCH v2 2/4] spi: s3c64xx: prepare for a different flavor of iowrite rep

There are SoCs (gs101) that allow only 32 bit register accesses. As the
requirement is rare enough, for those SoCs we'll open code in the driver
some s3c64xx_iowrite{8,16}_32_rep() accessors. Prepare for such addition.

Suggested-by: Sam Protsenko <semen.protsenko@...aro.org>
Signed-off-by: Tudor Ambarus <tudor.ambarus@...aro.org>
---
 drivers/spi/spi-s3c64xx.c | 35 +++++++++++++++++++++--------------
 1 file changed, 21 insertions(+), 14 deletions(-)

diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c
index 7f7eb8f742e4..eb79c6e4f509 100644
--- a/drivers/spi/spi-s3c64xx.c
+++ b/drivers/spi/spi-s3c64xx.c
@@ -414,6 +414,26 @@ static bool s3c64xx_spi_can_dma(struct spi_controller *host,
 
 }
 
+static void s3c64xx_iowrite_rep(const struct s3c64xx_spi_driver_data *sdd,
+				struct spi_transfer *xfer)
+{
+	void __iomem *addr = sdd->regs + S3C64XX_SPI_TX_DATA;
+	const void *buf = xfer->tx_buf;
+	unsigned int len = xfer->len;
+
+	switch (sdd->cur_bpw) {
+	case 32:
+		iowrite32_rep(addr, buf, len / 4);
+		break;
+	case 16:
+		iowrite16_rep(addr, buf, len / 2);
+		break;
+	default:
+		iowrite8_rep(addr, buf, len);
+		break;
+	}
+}
+
 static int s3c64xx_enable_datapath(struct s3c64xx_spi_driver_data *sdd,
 				    struct spi_transfer *xfer, int dma_mode)
 {
@@ -447,20 +467,7 @@ static int s3c64xx_enable_datapath(struct s3c64xx_spi_driver_data *sdd,
 			modecfg |= S3C64XX_SPI_MODE_TXDMA_ON;
 			ret = prepare_dma(&sdd->tx_dma, &xfer->tx_sg);
 		} else {
-			switch (sdd->cur_bpw) {
-			case 32:
-				iowrite32_rep(regs + S3C64XX_SPI_TX_DATA,
-					xfer->tx_buf, xfer->len / 4);
-				break;
-			case 16:
-				iowrite16_rep(regs + S3C64XX_SPI_TX_DATA,
-					xfer->tx_buf, xfer->len / 2);
-				break;
-			default:
-				iowrite8_rep(regs + S3C64XX_SPI_TX_DATA,
-					xfer->tx_buf, xfer->len);
-				break;
-			}
+			s3c64xx_iowrite_rep(sdd, xfer);
 		}
 	}
 
-- 
2.43.0.687.g38aa6559b0-goog