linux-kernel - [PATCH 2/5] spi: s3c64xx: group the CS signalling writes in a single function

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Date:	Fri, 17 Jun 2016 16:57:22 +0900
From:	Andi Shyti <andi.shyti@...sung.com>
To:	Mark Brown <broonie@...nel.org>
Cc:	Kukjin Kim <kgene@...nel.org>,
	Krzysztof Kozlowski <k.kozlowski@...sung.com>,
	linux-spi@...r.kernel.org, linux-kernel@...r.kernel.org,
	linux-arm-kernel@...ts.infradead.org,
	Andi Shyti <andi.shyti@...sung.com>,
	Andi Shyti <andi@...zian.org>
Subject: [PATCH 2/5] spi: s3c64xx: group the CS signalling writes in a single
 function

To enable/disable the CS line, the driver performs a writel in
the S3C64XX_SPI_SLAVE_SEL registers. Put together all the writes
in that register in a single function.

Signed-off-by: Andi Shyti <andi.shyti@...sung.com>
---
 drivers/spi/spi-s3c64xx.c | 36 ++++++++++++++++++++++++++----------
 1 file changed, 26 insertions(+), 10 deletions(-)

diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c
index 5a76a50..972367d 100644
--- a/drivers/spi/spi-s3c64xx.c
+++ b/drivers/spi/spi-s3c64xx.c
@@ -310,6 +310,28 @@ static void prepare_dma(struct s3c64xx_spi_dma_data *dma,
 	dma_async_issue_pending(dma->ch);
 }
 
+static void s3c64xx_spi_set_cs(struct spi_device *spi, bool enable)
+{
+	struct s3c64xx_spi_driver_data *sdd =
+					spi_master_get_devdata(spi->master);
+
+	if (enable) {
+		if (!(sdd->port_conf->quirks & S3C64XX_SPI_QUIRK_CS_AUTO)) {
+			writel(0, sdd->regs + S3C64XX_SPI_SLAVE_SEL);
+		} else {
+			u32 ssel = readl(sdd->regs + S3C64XX_SPI_SLAVE_SEL);
+
+			ssel |= (S3C64XX_SPI_SLAVE_AUTO |
+						S3C64XX_SPI_SLAVE_NSC_CNT_2);
+			writel(ssel, sdd->regs + S3C64XX_SPI_SLAVE_SEL);
+		}
+	} else {
+		if (!(sdd->port_conf->quirks & S3C64XX_SPI_QUIRK_CS_AUTO))
+		writel(S3C64XX_SPI_SLAVE_SIG_INACT,
+		sdd->regs + S3C64XX_SPI_SLAVE_SEL);
+	}
+}
+
 static int s3c64xx_spi_prepare_transfer(struct spi_master *spi)
 {
 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(spi);
@@ -706,12 +728,7 @@ static int s3c64xx_spi_transfer_one(struct spi_master *master,
 	enable_datapath(sdd, spi, xfer, use_dma);
 
 	/* Start the signals */
-	if (!(sdd->port_conf->quirks & S3C64XX_SPI_QUIRK_CS_AUTO))
-		writel(0, sdd->regs + S3C64XX_SPI_SLAVE_SEL);
-	else
-		writel(readl(sdd->regs + S3C64XX_SPI_SLAVE_SEL)
-			| S3C64XX_SPI_SLAVE_AUTO | S3C64XX_SPI_SLAVE_NSC_CNT_2,
-			sdd->regs + S3C64XX_SPI_SLAVE_SEL);
+	s3c64xx_spi_set_cs(spi, true);
 
 	spin_unlock_irqrestore(&sdd->lock, flags);
 
@@ -861,16 +878,15 @@ static int s3c64xx_spi_setup(struct spi_device *spi)
 
 	pm_runtime_mark_last_busy(&sdd->pdev->dev);
 	pm_runtime_put_autosuspend(&sdd->pdev->dev);
-	if (!(sdd->port_conf->quirks & S3C64XX_SPI_QUIRK_CS_AUTO))
-		writel(S3C64XX_SPI_SLAVE_SIG_INACT, sdd->regs + S3C64XX_SPI_SLAVE_SEL);
+	s3c64xx_spi_set_cs(spi, false);
+
 	return 0;
 
 setup_exit:
 	pm_runtime_mark_last_busy(&sdd->pdev->dev);
 	pm_runtime_put_autosuspend(&sdd->pdev->dev);
 	/* setup() returns with device de-selected */
-	if (!(sdd->port_conf->quirks & S3C64XX_SPI_QUIRK_CS_AUTO))
-		writel(S3C64XX_SPI_SLAVE_SIG_INACT, sdd->regs + S3C64XX_SPI_SLAVE_SEL);
+	s3c64xx_spi_set_cs(spi, false);
 
 	if (gpio_is_valid(spi->cs_gpio))
 		gpio_free(spi->cs_gpio);
-- 
2.8.1