spi: s3c64xx: Do not request CS GPIO on subsequent calls to .setup()

Comments in linux/spi/spi.h and observed behavior show that .setup()
callback can be called multiple times without corresponding calls to
.cleanup(), what was incorrectly assumed by spi-s3c64xx driver, leading
to failures trying to request CS GPIO multiple times.

This patch modifies the behavior of spi-s3c64xx driver to request CS
GPIO only on first call to .setup() after last .cleanup().

Signed-off-by: Tomasz Figa <tomasz.figa@gmail.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

drivers/spi/spi-s3c64xx.c

@@ -1071,20 +1071,21 @@ static int s3c64xx_spi_setup(struct spi_device *spi)
 		return -ENODEV;
 	}
 
-	/* Request gpio only if cs line is asserted by gpio pins */
-	if (sdd->cs_gpio) {
-		err = gpio_request_one(cs->line, GPIOF_OUT_INIT_HIGH,
-				       dev_name(&spi->dev));
-		if (err) {
-			dev_err(&spi->dev,
-				"Failed to get /CS gpio [%d]: %d\n",
-				cs->line, err);
-			goto err_gpio_req;
+	if (!spi_get_ctldata(spi)) {
+		/* Request gpio only if cs line is asserted by gpio pins */
+		if (sdd->cs_gpio) {
+			err = gpio_request_one(cs->line, GPIOF_OUT_INIT_HIGH,
+					dev_name(&spi->dev));
+			if (err) {
+				dev_err(&spi->dev,
+					"Failed to get /CS gpio [%d]: %d\n",
+					cs->line, err);
+				goto err_gpio_req;
+			}
 		}
-	}
 
-	if (!spi_get_ctldata(spi))
 		spi_set_ctldata(spi, cs);
+	}
 
 	sci = sdd->cntrlr_info;