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Subject[PATCH RFCv1 1/1] spi: Expand tx_nbits/rx_nbits to add 8-bit transfer
Date
Expand the tx_nbits/rx_nbits member of the spi_transfer struct to a 4 bit
value to allow specifying 8 bit transfers (SPI_NBITS_OCTO).

Change-Id: I0b7ab41b2caa8495da431944ccbc0b90942d5dd9
Signed-off-by: Girish Mahadevan <girishm@codeaurora.org>
---
include/linux/spi/spi.h | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h
index 857a9a1..45b958a 100644
--- a/include/linux/spi/spi.h
+++ b/include/linux/spi/spi.h
@@ -717,10 +717,11 @@ extern void spi_res_release(struct spi_master *master,
* by the results of previous messages and where the whole transaction
* ends when the chipselect goes intactive.
*
- * When SPI can transfer in 1x,2x or 4x. It can get this transfer information
+ * When SPI can transfer in 1x,2x,4x or 8x. It can get this transfer information
* from device through @tx_nbits and @rx_nbits. In Bi-direction, these
* two should both be set. User can set transfer mode with SPI_NBITS_SINGLE(1x)
- * SPI_NBITS_DUAL(2x) and SPI_NBITS_QUAD(4x) to support these three transfer.
+ * SPI_NBITS_DUAL(2x) SPI_NBITS_QUAD(4x) and SPI_NBITS_OCTO(8x) to support
+ * these four transfers.
*
* The code that submits an spi_message (and its spi_transfers)
* to the lower layers is responsible for managing its memory.
@@ -744,11 +745,12 @@ struct spi_transfer {
struct sg_table rx_sg;

unsigned cs_change:1;
- unsigned tx_nbits:3;
- unsigned rx_nbits:3;
+ unsigned tx_nbits:4;
+ unsigned rx_nbits:4;
#define SPI_NBITS_SINGLE 0x01 /* 1bit transfer */
#define SPI_NBITS_DUAL 0x02 /* 2bits transfer */
#define SPI_NBITS_QUAD 0x04 /* 4bits transfer */
+#define SPI_NBITS_OCTO 0x08 /* 4bits transfer */
u8 bits_per_word;
u16 delay_usecs;
u32 speed_hz;
--
Employee of Qualcomm Innovation Center, Inc.
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project
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