From f7005142dacea1769fba0152c493aaa61b33205c Mon Sep 17 00:00:00 2001 From: Alexandru Ardelean Date: Mon, 21 Dec 2020 17:29:34 +0200 Subject: spi: uapi: unify SPI modes into a single spi.h header 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 Signed-off-by: Alexandru Ardelean Link: https://lore.kernel.org/r/20201221152936.53873-1-alexandru.ardelean@analog.com Signed-off-by: Mark Brown --- include/uapi/linux/spi/spi.h | 31 +++++++++++++++++++++++++++++++ include/uapi/linux/spi/spidev.h | 30 +----------------------------- 2 files changed, 32 insertions(+), 29 deletions(-) create mode 100644 include/uapi/linux/spi/spi.h (limited to 'include/uapi/linux') 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 + +#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 #include - -/* User space versions of kernel symbols for SPI clocking modes, - * matching - */ - -#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 /* IOCTL commands */ -- cgit v1.2.3 From d962608ce2188a1d46ec9d356d6fad5cd6fc0341 Mon Sep 17 00:00:00 2001 From: Dragos Bogdan Date: Mon, 21 Dec 2020 17:29:35 +0200 Subject: spi: Add SPI_NO_TX/RX support 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 Signed-off-by: Alexandru Ardelean Link: https://lore.kernel.org/r/20201221152936.53873-2-alexandru.ardelean@analog.com Signed-off-by: Mark Brown --- drivers/spi/spi.c | 25 ++++++++++++++++++++----- include/linux/spi/spi.h | 17 +++++++++++++++++ include/uapi/linux/spi/spi.h | 10 ++++++++++ 3 files changed, 47 insertions(+), 5 deletions(-) (limited to 'include/uapi/linux') diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index 51d7c004fbab..ca75f4036eda 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 +3335,16 @@ 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 +3358,8 @@ 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 +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) @@ -3623,6 +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) 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 #include #include #include @@ -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 */ -- cgit v1.2.3