[PATCH v2 1/5] spi: s3c64xx: group the CS signalling writes in a single function

[Andi Shyti]

To enable/disable the CS line, the driver performs a writel in
the S3C64XX_SPI_SLAVE_SEL registers. Group the register's
configuration in a single function.

Signed-off-by: Andi Shyti <andi.sh...@samsung.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