spi: dspi: clear SPI_SR before enable interrupt

Once dspi is used in uboot, the SPI_SR have been set by some value.
At this time, if kernel enable the interrupt before clear the
status flag, that will trigger the wrong interrupt.

Signed-off-by: Yuan Yao <yao.yuan@nxp.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

drivers/spi/spi-fsl-dspi.c

@@ -70,6 +70,7 @@
 #define SPI_SR 0x2c
 #define SPI_SR_EOQF 0x10000000
 #define SPI_SR_TCFQF 0x80000000
+#define SPI_SR_CLEAR 0xdaad0000
 
 #define SPI_RSER 0x30
 #define SPI_RSER_EOQFE 0x10000000
@@ -646,6 +647,11 @@ static const struct regmap_config dspi_regmap_config = {
  .max_register = 0x88,
 };
 
+static void dspi_init(struct fsl_dspi *dspi)
+{
+ regmap_write(dspi->regmap, SPI_SR, SPI_SR_CLEAR);
+}
+
 static int dspi_probe(struct platform_device *pdev)
 {
  struct device_node *np = pdev->dev.of_node;
@@ -709,6 +715,7 @@ static int dspi_probe(struct platform_device *pdev)
  return PTR_ERR(dspi->regmap);
  }
 
+ dspi_init(dspi);
  dspi->irq = platform_get_irq(pdev, 0);
  if (dspi->irq < 0) {
  dev_err(&pdev->dev, "can't get platform irq\n");