[PATCH 1/3] spi: add SPI_RX_CPHA_FLIP mode bit

Baruch Siach baruch at tkos.co.il
Mon Apr 11 11:45:27 PDT 2022


From: Baruch Siach <baruch.siach at siklu.com>

Some SPI devices latch MOSI bits on one clock phase, but produce valid
MISO bits on the other phase. Add SPI_RX_CPHA_FLIP mode to instruct the
controller driver to flip CPHA for Rx (MISO) only transfers.

Signed-off-by: Baruch Siach <baruch.siach at siklu.com>
---
 include/uapi/linux/spi/spi.h | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/include/uapi/linux/spi/spi.h b/include/uapi/linux/spi/spi.h
index 236a85f08ded..9d5f58059703 100644
--- a/include/uapi/linux/spi/spi.h
+++ b/include/uapi/linux/spi/spi.h
@@ -27,6 +27,7 @@
 #define	SPI_TX_OCTAL		_BITUL(13)	/* transmit with 8 wires */
 #define	SPI_RX_OCTAL		_BITUL(14)	/* receive with 8 wires */
 #define	SPI_3WIRE_HIZ		_BITUL(15)	/* high impedance turnaround */
+#define	SPI_RX_CPHA_FLIP	_BITUL(16)	/* flip CPHA on Rx only xfer */
 
 /*
  * All the bits defined above should be covered by SPI_MODE_USER_MASK.
@@ -36,6 +37,6 @@
  * These bits must not overlap. A static assert check should make sure of that.
  * If adding extra bits, make sure to increase the bit index below as well.
  */
-#define SPI_MODE_USER_MASK	(_BITUL(16) - 1)
+#define SPI_MODE_USER_MASK	(_BITUL(17) - 1)
 
 #endif /* _UAPI_SPI_H */
-- 
2.35.1




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