This change moves all the SPI mode bits into a separate 'spi.h' header in
uAPI. This is meant to re-use these definitions inside the kernel as well
as export them to userspace (via uAPI).
The SPI mode definitions have usually been duplicated between between
'include/linux/spi/spi.h' and 'include/uapi/linux/spi/spidev.h', so
whenever adding a new entry, this would need to be put in both headers.
They've been moved from 'include/linux/spi/spi.h', since that seems a bit
more complete; the bits have descriptions and there is the SPI_MODE_X_MASK.
This change also does a conversion of these bitfields to _BITUL() macro.
Reviewed-by: Andy Shevchenko <[email protected]>
Signed-off-by: Alexandru Ardelean <[email protected]>
---
Changelog v4 -> v5:
* https://lore.kernel.org/linux-spi/[email protected]/
* added 'Reviewed-by: Andy Shevchenko <[email protected]>'
include/linux/spi/spi.h | 23 ++---------------------
include/uapi/linux/spi/spi.h | 31 +++++++++++++++++++++++++++++++
include/uapi/linux/spi/spidev.h | 30 +-----------------------------
3 files changed, 34 insertions(+), 50 deletions(-)
create mode 100644 include/uapi/linux/spi/spi.h
diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h
index aa09fdc8042d..a08c3f37e202 100644
--- a/include/linux/spi/spi.h
+++ b/include/linux/spi/spi.h
@@ -15,6 +15,8 @@
#include <linux/gpio/consumer.h>
#include <linux/ptp_clock_kernel.h>
+#include <uapi/linux/spi/spi.h>
+
struct dma_chan;
struct property_entry;
struct spi_controller;
@@ -165,27 +167,6 @@ struct spi_device {
u8 bits_per_word;
bool rt;
u32 mode;
-#define SPI_CPHA 0x01 /* clock phase */
-#define SPI_CPOL 0x02 /* clock polarity */
-#define SPI_MODE_0 (0|0) /* (original MicroWire) */
-#define SPI_MODE_1 (0|SPI_CPHA)
-#define SPI_MODE_2 (SPI_CPOL|0)
-#define SPI_MODE_3 (SPI_CPOL|SPI_CPHA)
-#define SPI_MODE_X_MASK (SPI_CPOL|SPI_CPHA)
-#define SPI_CS_HIGH 0x04 /* chipselect active high? */
-#define SPI_LSB_FIRST 0x08 /* per-word bits-on-wire */
-#define SPI_3WIRE 0x10 /* SI/SO signals shared */
-#define SPI_LOOP 0x20 /* loopback mode */
-#define SPI_NO_CS 0x40 /* 1 dev/bus, no chipselect */
-#define SPI_READY 0x80 /* slave pulls low to pause */
-#define SPI_TX_DUAL 0x100 /* transmit with 2 wires */
-#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_TX_OCTAL 0x2000 /* transmit with 8 wires */
-#define SPI_RX_OCTAL 0x4000 /* receive with 8 wires */
-#define SPI_3WIRE_HIZ 0x8000 /* high impedance turnaround */
int irq;
void *controller_state;
void *controller_data;
diff --git a/include/uapi/linux/spi/spi.h b/include/uapi/linux/spi/spi.h
new file mode 100644
index 000000000000..703b586f35df
--- /dev/null
+++ b/include/uapi/linux/spi/spi.h
@@ -0,0 +1,31 @@
+/* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */
+#ifndef _UAPI_SPI_H
+#define _UAPI_SPI_H
+
+#include <linux/const.h>
+
+#define SPI_CPHA _BITUL(0) /* clock phase */
+#define SPI_CPOL _BITUL(1) /* clock polarity */
+
+#define SPI_MODE_0 (0|0) /* (original MicroWire) */
+#define SPI_MODE_1 (0|SPI_CPHA)
+#define SPI_MODE_2 (SPI_CPOL|0)
+#define SPI_MODE_3 (SPI_CPOL|SPI_CPHA)
+#define SPI_MODE_X_MASK (SPI_CPOL|SPI_CPHA)
+
+#define SPI_CS_HIGH _BITUL(2) /* chipselect active high? */
+#define SPI_LSB_FIRST _BITUL(3) /* per-word bits-on-wire */
+#define SPI_3WIRE _BITUL(4) /* SI/SO signals shared */
+#define SPI_LOOP _BITUL(5) /* loopback mode */
+#define SPI_NO_CS _BITUL(6) /* 1 dev/bus, no chipselect */
+#define SPI_READY _BITUL(7) /* slave pulls low to pause */
+#define SPI_TX_DUAL _BITUL(8) /* transmit with 2 wires */
+#define SPI_TX_QUAD _BITUL(9) /* transmit with 4 wires */
+#define SPI_RX_DUAL _BITUL(10) /* receive with 2 wires */
+#define SPI_RX_QUAD _BITUL(11) /* receive with 4 wires */
+#define SPI_CS_WORD _BITUL(12) /* toggle cs after each word */
+#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 */
+
+#endif /* _UAPI_SPI_H */
diff --git a/include/uapi/linux/spi/spidev.h b/include/uapi/linux/spi/spidev.h
index d56427c0b3e0..0c3da08f2aff 100644
--- a/include/uapi/linux/spi/spidev.h
+++ b/include/uapi/linux/spi/spidev.h
@@ -25,35 +25,7 @@
#include <linux/types.h>
#include <linux/ioctl.h>
-
-/* User space versions of kernel symbols for SPI clocking modes,
- * matching <linux/spi/spi.h>
- */
-
-#define SPI_CPHA 0x01
-#define SPI_CPOL 0x02
-
-#define SPI_MODE_0 (0|0)
-#define SPI_MODE_1 (0|SPI_CPHA)
-#define SPI_MODE_2 (SPI_CPOL|0)
-#define SPI_MODE_3 (SPI_CPOL|SPI_CPHA)
-
-#define SPI_CS_HIGH 0x04
-#define SPI_LSB_FIRST 0x08
-#define SPI_3WIRE 0x10
-#define SPI_LOOP 0x20
-#define SPI_NO_CS 0x40
-#define SPI_READY 0x80
-#define SPI_TX_DUAL 0x100
-#define SPI_TX_QUAD 0x200
-#define SPI_RX_DUAL 0x400
-#define SPI_RX_QUAD 0x800
-#define SPI_CS_WORD 0x1000
-#define SPI_TX_OCTAL 0x2000
-#define SPI_RX_OCTAL 0x4000
-#define SPI_3WIRE_HIZ 0x8000
-
-/*---------------------------------------------------------------------------*/
+#include <linux/spi/spi.h>
/* IOCTL commands */
--
2.17.1
Following a change to the SPI framework, providing a value of zero for
'spi-rx-bus-width' and 'spi-tx-bus-width' is now possible and will
essentially mean that no RX or TX is allowed.
Reviewed-by: Rob Herring <[email protected]>
Signed-off-by: Alexandru Ardelean <[email protected]>
---
Changelog v4 -> v5:
* https://lore.kernel.org/linux-spi/[email protected]/
* added 'Reviewed-by: Rob Herring <[email protected]>'
Documentation/devicetree/bindings/spi/spi-controller.yaml | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/Documentation/devicetree/bindings/spi/spi-controller.yaml b/Documentation/devicetree/bindings/spi/spi-controller.yaml
index 5f505810104d..06786f1b43d2 100644
--- a/Documentation/devicetree/bindings/spi/spi-controller.yaml
+++ b/Documentation/devicetree/bindings/spi/spi-controller.yaml
@@ -152,8 +152,9 @@ patternProperties:
spi-rx-bus-width:
description:
Bus width to the SPI bus used for read transfers.
+ If 0 is provided, then no RX will be possible on this device.
$ref: /schemas/types.yaml#/definitions/uint32
- enum: [1, 2, 4, 8]
+ enum: [0, 1, 2, 4, 8]
default: 1
spi-rx-delay-us:
@@ -163,8 +164,9 @@ patternProperties:
spi-tx-bus-width:
description:
Bus width to the SPI bus used for write transfers.
+ If 0 is provided, then no TX will be possible on this device.
$ref: /schemas/types.yaml#/definitions/uint32
- enum: [1, 2, 4, 8]
+ enum: [0, 1, 2, 4, 8]
default: 1
spi-tx-delay-us:
--
2.17.1
From: Dragos Bogdan <[email protected]>
Transmit/receive only is a valid SPI mode. For example, the MOSI/TX line
might be missing from an ADC while for a DAC the MISO/RX line may be
optional. This patch adds these two new modes: SPI_NO_TX and
SPI_NO_RX. This way, the drivers will be able to identify if any of
these two lines is missing and to adjust the transfers accordingly.
Signed-off-by: Dragos Bogdan <[email protected]>
Signed-off-by: Alexandru Ardelean <[email protected]>
---
Changelog v4 -> v5:
* https://lore.kernel.org/linux-spi/[email protected]/
* using static_assert() vs BUILD_BUG_ON()
* added comments for SPI_MODE_KERNEL_MASK & SPI_MODE_USER_MASK
* using shorter form defining SPI_MODE_KERNEL_MASK & SPI_MODE_USER_MASK
drivers/spi/spi.c | 26 +++++++++++++++++++++-----
include/linux/spi/spi.h | 17 +++++++++++++++++
include/uapi/linux/spi/spi.h | 10 ++++++++++
3 files changed, 48 insertions(+), 5 deletions(-)
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index 51d7c004fbab..0b69934698c3 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -1941,6 +1941,9 @@ static int of_spi_parse_dt(struct spi_controller *ctlr, struct spi_device *spi,
/* Device DUAL/QUAD mode */
if (!of_property_read_u32(nc, "spi-tx-bus-width", &value)) {
switch (value) {
+ case 0:
+ spi->mode |= SPI_NO_TX;
+ break;
case 1:
break;
case 2:
@@ -1962,6 +1965,9 @@ static int of_spi_parse_dt(struct spi_controller *ctlr, struct spi_device *spi,
if (!of_property_read_u32(nc, "spi-rx-bus-width", &value)) {
switch (value) {
+ case 0:
+ spi->mode |= SPI_NO_RX;
+ break;
case 1:
break;
case 2:
@@ -3329,12 +3335,17 @@ int spi_setup(struct spi_device *spi)
unsigned bad_bits, ugly_bits;
int status;
- /* check mode to prevent that DUAL and QUAD set at the same time
+ /*
+ * check mode to prevent that any two of DUAL, QUAD and NO_MOSI/MISO
+ * are set at the same time
*/
- if (((spi->mode & SPI_TX_DUAL) && (spi->mode & SPI_TX_QUAD)) ||
- ((spi->mode & SPI_RX_DUAL) && (spi->mode & SPI_RX_QUAD))) {
+ if ((hweight_long(spi->mode &
+ (SPI_TX_DUAL | SPI_TX_QUAD | SPI_NO_TX)) > 1) ||
+ (hweight_long(spi->mode &
+ (SPI_RX_DUAL | SPI_RX_QUAD | SPI_NO_RX)) > 1)) {
dev_err(&spi->dev,
- "setup: can not select dual and quad at the same time\n");
+ "setup: can not select any two of dual, quad and no-rx/tx "
+ "at the same time\n");
return -EINVAL;
}
/* if it is SPI_3WIRE mode, DUAL and QUAD should be forbidden
@@ -3348,7 +3359,8 @@ int spi_setup(struct spi_device *spi)
* SPI_CS_WORD has a fallback software implementation,
* so it is ignored here.
*/
- bad_bits = spi->mode & ~(spi->controller->mode_bits | SPI_CS_WORD);
+ bad_bits = spi->mode & ~(spi->controller->mode_bits | SPI_CS_WORD |
+ SPI_NO_TX | SPI_NO_RX);
/* nothing prevents from working with active-high CS in case if it
* is driven by GPIO.
*/
@@ -3610,6 +3622,8 @@ static int __spi_validate(struct spi_device *spi, struct spi_message *message)
* 2. check tx/rx_nbits match the mode in spi_device
*/
if (xfer->tx_buf) {
+ if (spi->mode & SPI_NO_TX)
+ return -EINVAL;
if (xfer->tx_nbits != SPI_NBITS_SINGLE &&
xfer->tx_nbits != SPI_NBITS_DUAL &&
xfer->tx_nbits != SPI_NBITS_QUAD)
@@ -3623,6 +3637,8 @@ static int __spi_validate(struct spi_device *spi, struct spi_message *message)
}
/* check transfer rx_nbits */
if (xfer->rx_buf) {
+ if (spi->mode & SPI_NO_RX)
+ return -EINVAL;
if (xfer->rx_nbits != SPI_NBITS_SINGLE &&
xfer->rx_nbits != SPI_NBITS_DUAL &&
xfer->rx_nbits != SPI_NBITS_QUAD)
diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h
index a08c3f37e202..9bfdfaf286eb 100644
--- a/include/linux/spi/spi.h
+++ b/include/linux/spi/spi.h
@@ -6,6 +6,7 @@
#ifndef __LINUX_SPI_H
#define __LINUX_SPI_H
+#include <linux/bits.h>
#include <linux/device.h>
#include <linux/mod_devicetable.h>
#include <linux/slab.h>
@@ -166,6 +167,18 @@ struct spi_device {
u8 chip_select;
u8 bits_per_word;
bool rt;
+#define SPI_NO_TX BIT(31) /* no transmit wire */
+#define SPI_NO_RX BIT(30) /* no receive wire */
+ /*
+ * All bits defined above should be covered by SPI_MODE_KERNEL_MASK.
+ * The SPI_MODE_KERNEL_MASK has the SPI_MODE_USER_MASK counterpart,
+ * which is defined in 'include/uapi/linux/spi/spi.h'.
+ * The bits defined here are from bit 31 downwards, while in
+ * SPI_MODE_USER_MASK are from 0 upwards.
+ * These bits must not overlap. A static assert check should make sure of that.
+ * If adding extra bits, make sure to decrease the bit index below as well.
+ */
+#define SPI_MODE_KERNEL_MASK (~(BIT(30) - 1))
u32 mode;
int irq;
void *controller_state;
@@ -189,6 +202,10 @@ struct spi_device {
*/
};
+/* Make sure that SPI_MODE_KERNEL_MASK & SPI_MODE_USER_MASK don't overlap */
+static_assert((SPI_MODE_KERNEL_MASK & SPI_MODE_USER_MASK) == 0,
+ "SPI_MODE_USER_MASK & SPI_MODE_KERNEL_MASK must not overlap");
+
static inline struct spi_device *to_spi_device(struct device *dev)
{
return dev ? container_of(dev, struct spi_device, dev) : NULL;
diff --git a/include/uapi/linux/spi/spi.h b/include/uapi/linux/spi/spi.h
index 703b586f35df..236a85f08ded 100644
--- a/include/uapi/linux/spi/spi.h
+++ b/include/uapi/linux/spi/spi.h
@@ -28,4 +28,14 @@
#define SPI_RX_OCTAL _BITUL(14) /* receive with 8 wires */
#define SPI_3WIRE_HIZ _BITUL(15) /* high impedance turnaround */
+/*
+ * All the bits defined above should be covered by SPI_MODE_USER_MASK.
+ * The SPI_MODE_USER_MASK has the SPI_MODE_KERNEL_MASK counterpart in
+ * 'include/linux/spi/spi.h'. The bits defined here are from bit 0 upwards
+ * while in SPI_MODE_KERNEL_MASK they are from the other end downwards.
+ * 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)
+
#endif /* _UAPI_SPI_H */
--
2.17.1
> -----Original Message-----
> From: Andy Shevchenko <[email protected]>
> Sent: Monday, December 21, 2020 4:37 PM
> To: Ardelean, Alexandru <[email protected]>
> Cc: linux-spi <[email protected]>; devicetree
> <[email protected]>; Linux Kernel Mailing List <linux-
> [email protected]>; Bogdan, Dragos <[email protected]>;
> Mark Brown <[email protected]>; Rob Herring <[email protected]>
> Subject: Re: [PATCH v5 2/3] spi: Add SPI_NO_TX/RX support
>
> On Mon, Dec 21, 2020 at 4:34 PM Andy Shevchenko
> <[email protected]> wrote:
> > On Mon, Dec 21, 2020 at 4:15 PM Alexandru Ardelean
> > <[email protected]> wrote:
> > >
> > > From: Dragos Bogdan <[email protected]>
> > >
> > > Transmit/receive only is a valid SPI mode. For example, the MOSI/TX
> > > line might be missing from an ADC while for a DAC the MISO/RX line
> > > may be optional. This patch adds these two new modes: SPI_NO_TX and
> > > SPI_NO_RX. This way, the drivers will be able to identify if any of
> > > these two lines is missing and to adjust the transfers accordingly.
> > >
> > > Signed-off-by: Dragos Bogdan <[email protected]>
> >
> > Missed Co-developed-by: Alexandru ... ?
Nah, that's fine from my side without that tag.
> >
> > Anyway, looks good to me,
> > Reviewed-by: Andy Shevchenko <[email protected]>
>
> One nit, though...
>
> > > - "setup: can not select dual and quad at the same time\n");
> > > + "setup: can not select any two of dual, quad and no-rx/tx "
> > > + "at the same time\n");
>
> Can we avoid splitting string literals which are assumed to be on one line when
> printed?
It ends up at about 96 cols, but it's within limits.
The patch may have been written before the new 100 col-width limit.
>
> --
> With Best Regards,
> Andy Shevchenko
On Mon, Dec 21, 2020 at 5:19 PM Ardelean, Alexandru
<[email protected]> wrote:
> > -----Original Message-----
> > From: Andy Shevchenko <[email protected]>
> > Sent: Monday, December 21, 2020 4:37 PM
> > On Mon, Dec 21, 2020 at 4:34 PM Andy Shevchenko
> > <[email protected]> wrote:
...
> > One nit, though...
> >
> > > > - "setup: can not select dual and quad at the same time\n");
> > > > + "setup: can not select any two of dual, quad and no-rx/tx "
> > > > + "at the same time\n");
> >
> > Can we avoid splitting string literals which are assumed to be on one line when
> > printed?
>
> It ends up at about 96 cols, but it's within limits.
> The patch may have been written before the new 100 col-width limit.
JFYI: string literals do not have limits (neither 80, nor 100).
It's a special category.
--
With Best Regards,
Andy Shevchenko
On Mon, Dec 21, 2020 at 4:34 PM Andy Shevchenko
<[email protected]> wrote:
> On Mon, Dec 21, 2020 at 4:15 PM Alexandru Ardelean
> <[email protected]> wrote:
> >
> > From: Dragos Bogdan <[email protected]>
> >
> > Transmit/receive only is a valid SPI mode. For example, the MOSI/TX line
> > might be missing from an ADC while for a DAC the MISO/RX line may be
> > optional. This patch adds these two new modes: SPI_NO_TX and
> > SPI_NO_RX. This way, the drivers will be able to identify if any of
> > these two lines is missing and to adjust the transfers accordingly.
> >
> > Signed-off-by: Dragos Bogdan <[email protected]>
>
> Missed Co-developed-by: Alexandru ... ?
>
> Anyway, looks good to me,
> Reviewed-by: Andy Shevchenko <[email protected]>
One nit, though...
> > - "setup: can not select dual and quad at the same time\n");
> > + "setup: can not select any two of dual, quad and no-rx/tx "
> > + "at the same time\n");
Can we avoid splitting string literals which are assumed to be on one
line when printed?
--
With Best Regards,
Andy Shevchenko
On Mon, Dec 21, 2020 at 4:15 PM Alexandru Ardelean
<[email protected]> wrote:
>
> From: Dragos Bogdan <[email protected]>
>
> Transmit/receive only is a valid SPI mode. For example, the MOSI/TX line
> might be missing from an ADC while for a DAC the MISO/RX line may be
> optional. This patch adds these two new modes: SPI_NO_TX and
> SPI_NO_RX. This way, the drivers will be able to identify if any of
> these two lines is missing and to adjust the transfers accordingly.
>
> Signed-off-by: Dragos Bogdan <[email protected]>
Missed Co-developed-by: Alexandru ... ?
Anyway, looks good to me,
Reviewed-by: Andy Shevchenko <[email protected]>
> Signed-off-by: Alexandru Ardelean <[email protected]>
> ---
>
> Changelog v4 -> v5:
> * https://lore.kernel.org/linux-spi/[email protected]/
> * using static_assert() vs BUILD_BUG_ON()
> * added comments for SPI_MODE_KERNEL_MASK & SPI_MODE_USER_MASK
> * using shorter form defining SPI_MODE_KERNEL_MASK & SPI_MODE_USER_MASK
>
> drivers/spi/spi.c | 26 +++++++++++++++++++++-----
> include/linux/spi/spi.h | 17 +++++++++++++++++
> include/uapi/linux/spi/spi.h | 10 ++++++++++
> 3 files changed, 48 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
> index 51d7c004fbab..0b69934698c3 100644
> --- a/drivers/spi/spi.c
> +++ b/drivers/spi/spi.c
> @@ -1941,6 +1941,9 @@ static int of_spi_parse_dt(struct spi_controller *ctlr, struct spi_device *spi,
> /* Device DUAL/QUAD mode */
> if (!of_property_read_u32(nc, "spi-tx-bus-width", &value)) {
> switch (value) {
> + case 0:
> + spi->mode |= SPI_NO_TX;
> + break;
> case 1:
> break;
> case 2:
> @@ -1962,6 +1965,9 @@ static int of_spi_parse_dt(struct spi_controller *ctlr, struct spi_device *spi,
>
> if (!of_property_read_u32(nc, "spi-rx-bus-width", &value)) {
> switch (value) {
> + case 0:
> + spi->mode |= SPI_NO_RX;
> + break;
> case 1:
> break;
> case 2:
> @@ -3329,12 +3335,17 @@ int spi_setup(struct spi_device *spi)
> unsigned bad_bits, ugly_bits;
> int status;
>
> - /* check mode to prevent that DUAL and QUAD set at the same time
> + /*
> + * check mode to prevent that any two of DUAL, QUAD and NO_MOSI/MISO
> + * are set at the same time
> */
> - if (((spi->mode & SPI_TX_DUAL) && (spi->mode & SPI_TX_QUAD)) ||
> - ((spi->mode & SPI_RX_DUAL) && (spi->mode & SPI_RX_QUAD))) {
> + if ((hweight_long(spi->mode &
> + (SPI_TX_DUAL | SPI_TX_QUAD | SPI_NO_TX)) > 1) ||
> + (hweight_long(spi->mode &
> + (SPI_RX_DUAL | SPI_RX_QUAD | SPI_NO_RX)) > 1)) {
> dev_err(&spi->dev,
> - "setup: can not select dual and quad at the same time\n");
> + "setup: can not select any two of dual, quad and no-rx/tx "
> + "at the same time\n");
> return -EINVAL;
> }
> /* if it is SPI_3WIRE mode, DUAL and QUAD should be forbidden
> @@ -3348,7 +3359,8 @@ int spi_setup(struct spi_device *spi)
> * SPI_CS_WORD has a fallback software implementation,
> * so it is ignored here.
> */
> - bad_bits = spi->mode & ~(spi->controller->mode_bits | SPI_CS_WORD);
> + bad_bits = spi->mode & ~(spi->controller->mode_bits | SPI_CS_WORD |
> + SPI_NO_TX | SPI_NO_RX);
> /* nothing prevents from working with active-high CS in case if it
> * is driven by GPIO.
> */
> @@ -3610,6 +3622,8 @@ static int __spi_validate(struct spi_device *spi, struct spi_message *message)
> * 2. check tx/rx_nbits match the mode in spi_device
> */
> if (xfer->tx_buf) {
> + if (spi->mode & SPI_NO_TX)
> + return -EINVAL;
> if (xfer->tx_nbits != SPI_NBITS_SINGLE &&
> xfer->tx_nbits != SPI_NBITS_DUAL &&
> xfer->tx_nbits != SPI_NBITS_QUAD)
> @@ -3623,6 +3637,8 @@ static int __spi_validate(struct spi_device *spi, struct spi_message *message)
> }
> /* check transfer rx_nbits */
> if (xfer->rx_buf) {
> + if (spi->mode & SPI_NO_RX)
> + return -EINVAL;
> if (xfer->rx_nbits != SPI_NBITS_SINGLE &&
> xfer->rx_nbits != SPI_NBITS_DUAL &&
> xfer->rx_nbits != SPI_NBITS_QUAD)
> diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h
> index a08c3f37e202..9bfdfaf286eb 100644
> --- a/include/linux/spi/spi.h
> +++ b/include/linux/spi/spi.h
> @@ -6,6 +6,7 @@
> #ifndef __LINUX_SPI_H
> #define __LINUX_SPI_H
>
> +#include <linux/bits.h>
> #include <linux/device.h>
> #include <linux/mod_devicetable.h>
> #include <linux/slab.h>
> @@ -166,6 +167,18 @@ struct spi_device {
> u8 chip_select;
> u8 bits_per_word;
> bool rt;
> +#define SPI_NO_TX BIT(31) /* no transmit wire */
> +#define SPI_NO_RX BIT(30) /* no receive wire */
> + /*
> + * All bits defined above should be covered by SPI_MODE_KERNEL_MASK.
> + * The SPI_MODE_KERNEL_MASK has the SPI_MODE_USER_MASK counterpart,
> + * which is defined in 'include/uapi/linux/spi/spi.h'.
> + * The bits defined here are from bit 31 downwards, while in
> + * SPI_MODE_USER_MASK are from 0 upwards.
> + * These bits must not overlap. A static assert check should make sure of that.
> + * If adding extra bits, make sure to decrease the bit index below as well.
> + */
> +#define SPI_MODE_KERNEL_MASK (~(BIT(30) - 1))
> u32 mode;
> int irq;
> void *controller_state;
> @@ -189,6 +202,10 @@ struct spi_device {
> */
> };
>
> +/* Make sure that SPI_MODE_KERNEL_MASK & SPI_MODE_USER_MASK don't overlap */
> +static_assert((SPI_MODE_KERNEL_MASK & SPI_MODE_USER_MASK) == 0,
> + "SPI_MODE_USER_MASK & SPI_MODE_KERNEL_MASK must not overlap");
> +
> static inline struct spi_device *to_spi_device(struct device *dev)
> {
> return dev ? container_of(dev, struct spi_device, dev) : NULL;
> diff --git a/include/uapi/linux/spi/spi.h b/include/uapi/linux/spi/spi.h
> index 703b586f35df..236a85f08ded 100644
> --- a/include/uapi/linux/spi/spi.h
> +++ b/include/uapi/linux/spi/spi.h
> @@ -28,4 +28,14 @@
> #define SPI_RX_OCTAL _BITUL(14) /* receive with 8 wires */
> #define SPI_3WIRE_HIZ _BITUL(15) /* high impedance turnaround */
>
> +/*
> + * All the bits defined above should be covered by SPI_MODE_USER_MASK.
> + * The SPI_MODE_USER_MASK has the SPI_MODE_KERNEL_MASK counterpart in
> + * 'include/linux/spi/spi.h'. The bits defined here are from bit 0 upwards
> + * while in SPI_MODE_KERNEL_MASK they are from the other end downwards.
> + * 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)
> +
> #endif /* _UAPI_SPI_H */
> --
> 2.17.1
>
--
With Best Regards,
Andy Shevchenko