acpi: Support generation of SPI descriptor
Add a function to write a SPI descriptor to the generated ACPI code.
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Wolfgang Wallner <wolfgang.wallner@br-automation.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/include/spi.h b/include/spi.h
index a37900b..98ba9e7 100644
--- a/include/spi.h
+++ b/include/spi.h
@@ -13,8 +13,8 @@
#include <linux/bitops.h>
/* SPI mode flags */
-#define SPI_CPHA BIT(0) /* clock phase */
-#define SPI_CPOL BIT(1) /* clock polarity */
+#define SPI_CPHA BIT(0) /* clock phase (1 = SPI_CLOCK_PHASE_SECOND) */
+#define SPI_CPOL BIT(1) /* clock polarity (1 = SPI_POLARITY_HIGH) */
#define SPI_MODE_0 (0|0) /* (original MicroWire) */
#define SPI_MODE_1 (0|SPI_CPHA)
#define SPI_MODE_2 (SPI_CPOL|0)