[PATCH] spi: synquacer: Silence unused variable warnings

[Ilias Apalodimas]

When building with clang, the compiler compains with

drivers/spi/spi-synquacer.c:212:11: warning: variable 'bus_width' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized]
        else if (priv->mode & SPI_TX_OCTAL)
                 ^~~~~~~~~~~~~~~~~~~~~~~~~
drivers/spi/spi-synquacer.c:276:11: note: uninitialized use occurs here
        val |= ((bus_width >> 1) << BUS_WIDTH);
                 ^~~~~~~~~
drivers/spi/spi-synquacer.c:212:7: note: remove the 'if' if its condition is always true
        else if (priv->mode & SPI_TX_OCTAL)
             ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/spi/spi-synquacer.c:189:25: note: initialize the variable 'bus_width' to silence this warning

So initialize bus_width to 1 and add a warning if none of the configured
modes matches

Signed-off-by: Ilias Apalodimas <ilias.apalodimas at linaro.org>
---
 drivers/spi/spi-synquacer.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/spi/spi-synquacer.c b/drivers/spi/spi-synquacer.c
index 0cae3dfc778f..0f5d0a30c39d 100644
--- a/drivers/spi/spi-synquacer.c
+++ b/drivers/spi/spi-synquacer.c
@@ -186,7 +186,7 @@ static void synquacer_spi_config(struct udevice *dev, void *rx, const void *tx)
 	struct udevice *bus = dev->parent;
 	struct synquacer_spi_priv *priv = dev_get_priv(bus);
 	struct dm_spi_slave_plat *slave_plat = dev_get_parent_plat(dev);
-	u32 val, div, bus_width;
+	u32 val, div, bus_width = 1;
 	int rwflag;
 
 	rwflag = (rx ? 1 : 0) | (tx ? 2 : 0);
@@ -211,6 +211,8 @@ static void synquacer_spi_config(struct udevice *dev, void *rx, const void *tx)
 		bus_width = 4;
 	else if (priv->mode & SPI_TX_OCTAL)
 		bus_width = 8;
+	else
+		log_warning("SPI mode not configured, setting to byte mode\n");
 
 	div = DIV_ROUND_UP(125000000, priv->speed);
 
-- 
2.39.2