[PATCH v5 1/7] spi: add support for octal mode I/O data transfer

Yogesh Narayan Gaur
2018-12-03T08:39:14Z

Add flags for Octal mode I/O data transfer
Required for the SPI controller which can do the data transfer (TX/RX)
on 8 data lines e.g. NXP FlexSPI controller.
SPI_TX_OCTAL: transmit with 8 wires
SPI_RX_OCTAL: receive with 8 wires

Signed-off-by: Yogesh Gaur <yogeshnarayan.gaur@nxp.com>
Reviewed-by: Boris Brezillon <boris.brezillon@bootlin.com>
---
Changes for v5:
- Modified string 'octo' with 'octal'.
Changes for v4:
- Rebase on top of v4.20-rc2
Changes for v3:
- Modified string 'octal' with 'octo'.
- Add octo mode support in spi_setup().
Changes for v2:
- Incorporated review comments of Boris.
---
drivers/spi/spi.c | 12 ++++++++++--
include/linux/spi/spi.h | 4 +++-
2 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index 6ca5940..95249b8 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -1617,6 +1617,9 @@ static int of_spi_parse_dt(struct spi_controller *ctlr, struct spi_device *spi,
case 4:
spi->mode |= SPI_TX_QUAD;
break;
+ case 8:
+ spi->mode |= SPI_TX_OCTAL;
+ break;
default:
dev_warn(&ctlr->dev,
"spi-tx-bus-width %d not supported\n",
@@ -1635,6 +1638,9 @@ static int of_spi_parse_dt(struct spi_controller *ctlr, struct spi_device *spi,
case 4:
spi->mode |= SPI_RX_QUAD;
break;
+ case 8:
+ spi->mode |= SPI_RX_OCTAL;
+ break;
default:
dev_warn(&ctlr->dev,
"spi-rx-bus-width %d not supported\n",
@@ -2823,7 +2829,8 @@ int spi_setup(struct spi_device *spi)
/* if it is SPI_3WIRE mode, DUAL and QUAD should be forbidden
*/
if ((spi->mode & SPI_3WIRE) && (spi->mode &
- (SPI_TX_DUAL | SPI_TX_QUAD | SPI_RX_DUAL | SPI_RX_QUAD)))
+ (SPI_TX_DUAL | SPI_TX_QUAD | SPI_TX_OCTAL |
+ SPI_RX_DUAL | SPI_RX_QUAD | SPI_RX_OCTAL)))
return -EINVAL;
/* help drivers fail *cleanly* when they need options
* that aren't supported with their current controller
@@ -2832,7 +2839,8 @@ int spi_setup(struct spi_device *spi)
*/
bad_bits = spi->mode & ~(spi->controller->mode_bits | SPI_CS_WORD);
ugly_bits = bad_bits &
- (SPI_TX_DUAL | SPI_TX_QUAD | SPI_RX_DUAL | SPI_RX_QUAD);
+ (SPI_TX_DUAL | SPI_TX_QUAD | SPI_TX_OCTAL |
+ SPI_RX_DUAL | SPI_RX_QUAD | SPI_RX_OCTAL);
if (ugly_bits) {
dev_warn(&spi->dev,
"setup: ignoring unsupported mode bits %x\n",
diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h
index 6be77fa..0c1ca5d 100644
--- a/include/linux/spi/spi.h
+++ b/include/linux/spi/spi.h
@@ -154,7 +154,9 @@ struct spi_device {
#define SPI_TX_QUAD 0x200 /* transmit with 4 wires */
#define SPI_RX_DUAL 0x400 /* receive with 2 wires */
#define SPI_RX_QUAD 0x800 /* receive with 4 wires */
-#define SPI_CS_WORD 0x1000 /* toggle cs after each word */
+#define SPI_CS_WORD 0x1000 /* toggle cs after each word */
+#define SPI_TX_OCTAL 0x2000 /* transmit with 8 wires */
+#define SPI_RX_OCTAL 0x4000 /* receive with 8 wires */
int irq;
void *controller_state;
void *controller_data;
--
2.7.4