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* [PATCH v4 1/3] spi: uapi: unify SPI modes into a single spi.h header
@ 2020-12-03 14:05 Alexandru Ardelean
  2020-12-03 14:05 ` [PATCH v4 2/3] spi: Add SPI_NO_TX/RX support Alexandru Ardelean
                   ` (2 more replies)
  0 siblings, 3 replies; 8+ messages in thread
From: Alexandru Ardelean @ 2020-12-03 14:05 UTC (permalink / raw)
  To: linux-spi, devicetree, linux-kernel
  Cc: broonie, robh+dt, dragos.bogdan, andy.shevchenko, Alexandru Ardelean

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.

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
---

Changelog v3 -> v4:
* https://lore.kernel.org/linux-spi/20201127130834.136348-1-alexandru.ardelean@analog.com/
* uapi -> uAPI in comment
* removed extra license text in 'uapi/linux/spi/spi.h'
* using _BITUL() macro

 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


^ permalink raw reply related	[flat|nested] 8+ messages in thread

* [PATCH v4 2/3] spi: Add SPI_NO_TX/RX support
  2020-12-03 14:05 [PATCH v4 1/3] spi: uapi: unify SPI modes into a single spi.h header Alexandru Ardelean
@ 2020-12-03 14:05 ` Alexandru Ardelean
  2020-12-03 14:10   ` Andy Shevchenko
  2020-12-03 14:24   ` Andy Shevchenko
  2020-12-03 14:05 ` [PATCH v4 3/3] spi: dt-bindings: document zero value for spi-{rx,tx}-bus-width properties Alexandru Ardelean
  2020-12-03 14:14 ` [PATCH v4 1/3] spi: uapi: unify SPI modes into a single spi.h header Andy Shevchenko
  2 siblings, 2 replies; 8+ messages in thread
From: Alexandru Ardelean @ 2020-12-03 14:05 UTC (permalink / raw)
  To: linux-spi, devicetree, linux-kernel
  Cc: broonie, robh+dt, dragos.bogdan, andy.shevchenko, Alexandru Ardelean

From: Dragos Bogdan <dragos.bogdan@analog.com>

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 <dragos.bogdan@analog.com>
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
---

Changelog v3 -> v4:
* https://lore.kernel.org/linux-spi/20201127130834.136348-2-alexandru.ardelean@analog.com/
* moved SPI_NO_TX + SPI_NO_RX to internal spi.h header
* added SPI_MODE_USER_MASK & SPI_MODE_KERNEL_MASK + BUILD_BUG_ON() check

 drivers/spi/spi.c            | 28 +++++++++++++++++++++++-----
 include/linux/spi/spi.h      |  4 ++++
 include/uapi/linux/spi/spi.h |  6 ++++++
 3 files changed, 33 insertions(+), 5 deletions(-)

diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index cd3c395b4e90..8668626c4a46 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.
 	 */
@@ -3609,6 +3621,8 @@ 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)
@@ -3622,6 +3636,8 @@ 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)
@@ -4190,6 +4206,8 @@ static int __init spi_init(void)
 {
 	int	status;
 
+	BUILD_BUG_ON(SPI_MODE_USER_MASK & SPI_MODE_KERNEL_MASK);
+
 	buf = kmalloc(SPI_BUFSIZ, GFP_KERNEL);
 	if (!buf) {
 		status = -ENOMEM;
diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h
index a08c3f37e202..6f1905f729c4 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 +167,9 @@ 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 */
+#define SPI_MODE_KERNEL_MASK	(SPI_NO_TX | SPI_NO_RX)
 	u32			mode;
 	int			irq;
 	void			*controller_state;
diff --git a/include/uapi/linux/spi/spi.h b/include/uapi/linux/spi/spi.h
index 703b586f35df..e5c58748422e 100644
--- a/include/uapi/linux/spi/spi.h
+++ b/include/uapi/linux/spi/spi.h
@@ -28,4 +28,10 @@
 #define	SPI_RX_OCTAL		_BITUL(14)	/* receive with 8 wires */
 #define	SPI_3WIRE_HIZ		_BITUL(15)	/* high impedance turnaround */
 
+#define SPI_MODE_USER_MASK	\
+	(SPI_CPHA | SPI_CPOL | SPI_CS_HIGH | SPI_LSB_FIRST | \
+	 SPI_3WIRE | SPI_LOOP | SPI_NO_CS | SPI_READY | \
+	 SPI_TX_DUAL | SPI_TX_QUAD | SPI_RX_DUAL | SPI_RX_QUAD | \
+	 SPI_CS_WORD | SPI_TX_OCTAL | SPI_RX_OCTAL | SPI_3WIRE_HIZ)
+
 #endif /* _UAPI_SPI_H */
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 8+ messages in thread

* [PATCH v4 3/3] spi: dt-bindings: document zero value for spi-{rx,tx}-bus-width properties
  2020-12-03 14:05 [PATCH v4 1/3] spi: uapi: unify SPI modes into a single spi.h header Alexandru Ardelean
  2020-12-03 14:05 ` [PATCH v4 2/3] spi: Add SPI_NO_TX/RX support Alexandru Ardelean
@ 2020-12-03 14:05 ` Alexandru Ardelean
  2020-12-09 20:13   ` Rob Herring
  2020-12-03 14:14 ` [PATCH v4 1/3] spi: uapi: unify SPI modes into a single spi.h header Andy Shevchenko
  2 siblings, 1 reply; 8+ messages in thread
From: Alexandru Ardelean @ 2020-12-03 14:05 UTC (permalink / raw)
  To: linux-spi, devicetree, linux-kernel
  Cc: broonie, robh+dt, dragos.bogdan, andy.shevchenko, Alexandru Ardelean

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.

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
---

Changelog v3 -> v4:
* https://lore.kernel.org/linux-spi/20201127130834.136348-3-alexandru.ardelean@analog.com/
* fix typos

 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 1b56d5e40f1f..cf663e4a4afe 100644
--- a/Documentation/devicetree/bindings/spi/spi-controller.yaml
+++ b/Documentation/devicetree/bindings/spi/spi-controller.yaml
@@ -125,8 +125,9 @@ 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:
@@ -136,8 +137,9 @@ 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


^ permalink raw reply related	[flat|nested] 8+ messages in thread

* Re: [PATCH v4 2/3] spi: Add SPI_NO_TX/RX support
  2020-12-03 14:05 ` [PATCH v4 2/3] spi: Add SPI_NO_TX/RX support Alexandru Ardelean
@ 2020-12-03 14:10   ` Andy Shevchenko
  2020-12-03 14:27     ` Andy Shevchenko
  2020-12-03 14:24   ` Andy Shevchenko
  1 sibling, 1 reply; 8+ messages in thread
From: Andy Shevchenko @ 2020-12-03 14:10 UTC (permalink / raw)
  To: Alexandru Ardelean
  Cc: linux-spi, devicetree, Linux Kernel Mailing List, Mark Brown,
	Rob Herring, Bogdan, Dragos

On Thu, Dec 3, 2020 at 4:00 PM Alexandru Ardelean
<alexandru.ardelean@analog.com> wrote:
> From: Dragos Bogdan <dragos.bogdan@analog.com>
>
> 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.

...

> +       BUILD_BUG_ON(SPI_MODE_USER_MASK & SPI_MODE_KERNEL_MASK);

Please, use static_assert() as I have been pointed out. It may be
located outside of a function scope. You may attach it directly to the
definition of the KERNEL_MASK (I haven't tried yet with header
though).

...

> +#define SPI_NO_TX      BIT(31)         /* no transmit wire */
> +#define SPI_NO_RX      BIT(30)         /* no receive wire */
> +#define SPI_MODE_KERNEL_MASK   (SPI_NO_TX | SPI_NO_RX)

This needs a comment to explain what's going on with the flags (split).

-- 
With Best Regards,
Andy Shevchenko

^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [PATCH v4 1/3] spi: uapi: unify SPI modes into a single spi.h header
  2020-12-03 14:05 [PATCH v4 1/3] spi: uapi: unify SPI modes into a single spi.h header Alexandru Ardelean
  2020-12-03 14:05 ` [PATCH v4 2/3] spi: Add SPI_NO_TX/RX support Alexandru Ardelean
  2020-12-03 14:05 ` [PATCH v4 3/3] spi: dt-bindings: document zero value for spi-{rx,tx}-bus-width properties Alexandru Ardelean
@ 2020-12-03 14:14 ` Andy Shevchenko
  2 siblings, 0 replies; 8+ messages in thread
From: Andy Shevchenko @ 2020-12-03 14:14 UTC (permalink / raw)
  To: Alexandru Ardelean
  Cc: linux-spi, devicetree, Linux Kernel Mailing List, Mark Brown,
	Rob Herring, Bogdan, Dragos

On Thu, Dec 3, 2020 at 4:00 PM Alexandru Ardelean
<alexandru.ardelean@analog.com> wrote:
>
> 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.

Looks nice to me now, FWIW,
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>

> Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
> ---
>
> Changelog v3 -> v4:
> * https://lore.kernel.org/linux-spi/20201127130834.136348-1-alexandru.ardelean@analog.com/
> * uapi -> uAPI in comment
> * removed extra license text in 'uapi/linux/spi/spi.h'
> * using _BITUL() macro
>
>  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
>


-- 
With Best Regards,
Andy Shevchenko

^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [PATCH v4 2/3] spi: Add SPI_NO_TX/RX support
  2020-12-03 14:05 ` [PATCH v4 2/3] spi: Add SPI_NO_TX/RX support Alexandru Ardelean
  2020-12-03 14:10   ` Andy Shevchenko
@ 2020-12-03 14:24   ` Andy Shevchenko
  1 sibling, 0 replies; 8+ messages in thread
From: Andy Shevchenko @ 2020-12-03 14:24 UTC (permalink / raw)
  To: Alexandru Ardelean
  Cc: linux-spi, devicetree, Linux Kernel Mailing List, Mark Brown,
	Rob Herring, Bogdan, Dragos

On Thu, Dec 3, 2020 at 4:00 PM Alexandru Ardelean
<alexandru.ardelean@analog.com> wrote:

> +#define SPI_MODE_USER_MASK     \
> +       (SPI_CPHA | SPI_CPOL | SPI_CS_HIGH | SPI_LSB_FIRST | \
> +        SPI_3WIRE | SPI_LOOP | SPI_NO_CS | SPI_READY | \
> +        SPI_TX_DUAL | SPI_TX_QUAD | SPI_RX_DUAL | SPI_RX_QUAD | \
> +        SPI_CS_WORD | SPI_TX_OCTAL | SPI_RX_OCTAL | SPI_3WIRE_HIZ)

Forgot to comment on this. Since it's an uAPI we may not fill the
holes (if any) in the future with the different semantics of values.
And this huge list of names is rather hard to read.

#define SPI_MODE_USER_MASK    (_BITUL(16) - 1)

would be sufficient.

For the record, I was thinking about providing MAX or LAST or
something like that instead of MASK and do the rest in kernel headers
/ modules, but it seems equally good/bad. Let's stick with mask as in
my initial propose and your current code.

-- 
With Best Regards,
Andy Shevchenko

^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [PATCH v4 2/3] spi: Add SPI_NO_TX/RX support
  2020-12-03 14:10   ` Andy Shevchenko
@ 2020-12-03 14:27     ` Andy Shevchenko
  0 siblings, 0 replies; 8+ messages in thread
From: Andy Shevchenko @ 2020-12-03 14:27 UTC (permalink / raw)
  To: Alexandru Ardelean
  Cc: linux-spi, devicetree, Linux Kernel Mailing List, Mark Brown,
	Rob Herring, Bogdan, Dragos

On Thu, Dec 3, 2020 at 4:10 PM Andy Shevchenko
<andy.shevchenko@gmail.com> wrote:
> On Thu, Dec 3, 2020 at 4:00 PM Alexandru Ardelean
> <alexandru.ardelean@analog.com> wrote:

> > +#define SPI_NO_TX      BIT(31)         /* no transmit wire */
> > +#define SPI_NO_RX      BIT(30)         /* no receive wire */
> > +#define SPI_MODE_KERNEL_MASK   (SPI_NO_TX | SPI_NO_RX)
>
> This needs a comment to explain what's going on with the flags (split).

...and to be consistent with proposal in uAPI:

#define SPI_MODE_KERNEL_MASK   (~(BIT(30) - 1))

-- 
With Best Regards,
Andy Shevchenko

^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [PATCH v4 3/3] spi: dt-bindings: document zero value for spi-{rx,tx}-bus-width properties
  2020-12-03 14:05 ` [PATCH v4 3/3] spi: dt-bindings: document zero value for spi-{rx,tx}-bus-width properties Alexandru Ardelean
@ 2020-12-09 20:13   ` Rob Herring
  0 siblings, 0 replies; 8+ messages in thread
From: Rob Herring @ 2020-12-09 20:13 UTC (permalink / raw)
  To: Alexandru Ardelean
  Cc: linux-spi, broonie, andy.shevchenko, devicetree, linux-kernel,
	robh+dt, dragos.bogdan

On Thu, 03 Dec 2020 16:05:31 +0200, Alexandru Ardelean wrote:
> 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.
> 
> Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
> ---
> 
> Changelog v3 -> v4:
> * https://lore.kernel.org/linux-spi/20201127130834.136348-3-alexandru.ardelean@analog.com/
> * fix typos
> 
>  Documentation/devicetree/bindings/spi/spi-controller.yaml | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 

Reviewed-by: Rob Herring <robh@kernel.org>

^ permalink raw reply	[flat|nested] 8+ messages in thread

end of thread, other threads:[~2020-12-09 20:14 UTC | newest]

Thread overview: 8+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-12-03 14:05 [PATCH v4 1/3] spi: uapi: unify SPI modes into a single spi.h header Alexandru Ardelean
2020-12-03 14:05 ` [PATCH v4 2/3] spi: Add SPI_NO_TX/RX support Alexandru Ardelean
2020-12-03 14:10   ` Andy Shevchenko
2020-12-03 14:27     ` Andy Shevchenko
2020-12-03 14:24   ` Andy Shevchenko
2020-12-03 14:05 ` [PATCH v4 3/3] spi: dt-bindings: document zero value for spi-{rx,tx}-bus-width properties Alexandru Ardelean
2020-12-09 20:13   ` Rob Herring
2020-12-03 14:14 ` [PATCH v4 1/3] spi: uapi: unify SPI modes into a single spi.h header Andy Shevchenko

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