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/*
* Copyright (c) 2015 Intel Corporation
*
* SPDX-License-Identifier: Apache-2.0
*/
/**
* @file
* @brief Public API for SPI drivers and applications
*/
#ifndef ZEPHYR_INCLUDE_DRIVERS_SPI_H_
#define ZEPHYR_INCLUDE_DRIVERS_SPI_H_
/**
* @brief SPI Interface
* @defgroup spi_interface SPI Interface
* @ingroup io_interfaces
* @{
*/
#include <zephyr/types.h>
#include <stddef.h>
#include <device.h>
#include <drivers/gpio.h>
#ifdef __cplusplus
extern "C" {
#endif
/**
* @brief SPI operational mode
*/
#define SPI_OP_MODE_MASTER 0
#define SPI_OP_MODE_SLAVE BIT(0)
#define SPI_OP_MODE_MASK 0x1
#define SPI_OP_MODE_GET(_operation_) ((_operation_) & SPI_OP_MODE_MASK)
/**
* @brief SPI Polarity & Phase Modes
*/
/**
* Clock Polarity: if set, clock idle state will be 1
* and active state will be 0. If untouched, the inverse will be true
* which is the default.
*/
#define SPI_MODE_CPOL BIT(1)
/**
* Clock Phase: this dictates when is the data captured, and depends
* clock's polarity. When SPI_MODE_CPOL is set and this bit as well,
* capture will occur on low to high transition and high to low if
* this bit is not set (default). This is fully reversed if CPOL is
* not set.
*/
#define SPI_MODE_CPHA BIT(2)
/**
* Whatever data is transmitted is looped-back to the receiving buffer of
* the controller. This is fully controller dependent as some may not
* support this, and can be used for testing purposes only.
*/
#define SPI_MODE_LOOP BIT(3)
#define SPI_MODE_MASK (0xE)
#define SPI_MODE_GET(_mode_) \
((_mode_) & SPI_MODE_MASK)
/**
* @brief SPI Transfer modes (host controller dependent)
*/
#define SPI_TRANSFER_MSB (0)
#define SPI_TRANSFER_LSB BIT(4)
/**
* @brief SPI word size
*/
#define SPI_WORD_SIZE_SHIFT (5)
#define SPI_WORD_SIZE_MASK (0x3F << SPI_WORD_SIZE_SHIFT)
#define SPI_WORD_SIZE_GET(_operation_) \
(((_operation_) & SPI_WORD_SIZE_MASK) >> SPI_WORD_SIZE_SHIFT)
#define SPI_WORD_SET(_word_size_) \
((_word_size_) << SPI_WORD_SIZE_SHIFT)
/**
* @brief SPI MISO lines
*
* Some controllers support dual, quad or octal MISO lines connected to slaves.
* Default is single, which is the case most of the time.
*/
#define SPI_LINES_SINGLE (0 << 11)
#define SPI_LINES_DUAL (1 << 11)
#define SPI_LINES_QUAD (2 << 11)
#define SPI_LINES_OCTAL (3 << 11)
#define SPI_LINES_MASK (0x3 << 11)
/**
* @brief Specific SPI devices control bits
*/
/* Requests - if possible - to keep CS asserted after the transaction */
#define SPI_HOLD_ON_CS BIT(13)
/* Keep the device locked after the transaction for the current config.
* Use this with extreme caution (see spi_release() below) as it will
* prevent other callers to access the SPI device until spi_release() is
* properly called.
*/
#define SPI_LOCK_ON BIT(14)
/* Active high logic on CS - Usually, and by default, CS logic is active
* low. However, some devices may require the reverse logic: active high.
* This bit will request the controller to use that logic. Note that not
* all controllers are able to handle that natively. In this case deferring
* the CS control to a gpio line through struct spi_cs_control would be
* the solution.
*/
#define SPI_CS_ACTIVE_HIGH BIT(15)
/**
* @brief SPI Chip Select control structure
*
* This can be used to control a CS line via a GPIO line, instead of
* using the controller inner CS logic.
*
* @param gpio_dev is a valid pointer to an actual GPIO device. A NULL pointer
* can be provided to full inhibit CS control if necessary.
* @param gpio_pin is a number representing the gpio PIN that will be used
* to act as a CS line
* @param delay is a delay in microseconds to wait before starting the
* transmission and before releasing the CS line
* @param gpio_dt_flags is the devicetree flags corresponding to how the CS
* line should be driven. GPIO_ACTIVE_LOW/GPIO_ACTIVE_HIGH should be
* equivalent to SPI_CS_ACTIVE_HIGH/SPI_CS_ACTIVE_LOW options in struct
* spi_config.
*/
struct spi_cs_control {
const struct device *gpio_dev;
uint32_t delay;
gpio_pin_t gpio_pin;
gpio_dt_flags_t gpio_dt_flags;
};
#ifndef __cplusplus
/**
* @brief Initialize and get a pointer to a @p spi_cs_control from a
* devicetree node identifier
*
* This helper is useful for initializing a device on a SPI bus. It
* initializes a struct spi_cs_control and returns a pointer to it.
* Here, @p node_id is a node identifier for a SPI device, not a SPI
* controller.
*
* Example devicetree fragment:
*
* spi@... {
* cs-gpios = <&gpio0 1 GPIO_ACTIVE_LOW>;
* spidev: spi-device@0 { ... };
* };
*
* Assume that @p gpio0 follows the standard convention for specifying
* GPIOs, i.e. it has the following in its binding:
*
* gpio-cells:
* - pin
* - flags
*
* Example usage:
*
* struct spi_cs_control *ctrl =
* SPI_CS_CONTROL_PTR_DT(DT_NODELABEL(spidev), 2);
*
* This example is equivalent to:
*
* struct spi_cs_control *ctrl =
* &(struct spi_cs_control) {
* .gpio_dev = DEVICE_DT_GET(DT_NODELABEL(gpio0)),
* .delay = 2,
* .gpio_pin = 1,
* .gpio_dt_flags = GPIO_ACTIVE_LOW
* };
*
* This macro is not available in C++.
*
* @param node_id Devicetree node identifier for a device on a SPI bus
* @param delay_ The @p delay field to set in the @p spi_cs_control
* @return a pointer to the @p spi_cs_control structure
*/
#define SPI_CS_CONTROL_PTR_DT(node_id, delay_) \
(&(struct spi_cs_control) { \
.gpio_dev = DEVICE_DT_GET( \
DT_SPI_DEV_CS_GPIOS_CTLR(node_id)), \
.delay = (delay_), \
.gpio_pin = DT_SPI_DEV_CS_GPIOS_PIN(node_id), \
.gpio_dt_flags = DT_SPI_DEV_CS_GPIOS_FLAGS(node_id), \
})
/**
* @brief Get a pointer to a @p spi_cs_control from a devicetree node
*
* This is equivalent to
* <tt>SPI_CS_CONTROL_PTR_DT(DT_DRV_INST(inst), delay)</tt>.
*
* Therefore, @p DT_DRV_COMPAT must already be defined before using
* this macro.
*
* This macro is not available in C++.
*
* @param inst Devicetree node instance number
* @param delay_ The @p delay field to set in the @p spi_cs_control
* @return a pointer to the @p spi_cs_control structure
*/
#define SPI_CS_CONTROL_PTR_DT_INST(inst, delay_) \
SPI_CS_CONTROL_PTR_DT(DT_DRV_INST(inst), delay_)
#endif
/**
* @brief SPI controller configuration structure
*
* @param frequency is the bus frequency in Hertz
* @param operation is a bit field with the following parts:
*
* operational mode [ 0 ] - master or slave.
* mode [ 1 : 3 ] - Polarity, phase and loop mode.
* transfer [ 4 ] - LSB or MSB first.
* word_size [ 5 : 10 ] - Size of a data frame in bits.
* lines [ 11 : 12 ] - MISO lines: Single/Dual/Quad/Octal.
* cs_hold [ 13 ] - Hold on the CS line if possible.
* lock_on [ 14 ] - Keep resource locked for the caller.
* cs_active_high [ 15 ] - Active high CS logic.
* @param slave is the slave number from 0 to host controller slave limit.
* @param cs is a valid pointer on a struct spi_cs_control is CS line is
* emulated through a gpio line, or NULL otherwise.
*
* @note Only cs_hold and lock_on can be changed between consecutive
* transceive call. Rest of the attributes are not meant to be tweaked.
*
* @warning Most drivers use pointer comparison to determine whether a
* passed configuration is different from one used in a previous
* transaction. Changes to fields in the structure may not be
* detected.
*/
struct spi_config {
uint32_t frequency;
uint16_t operation;
uint16_t slave;
const struct spi_cs_control *cs;
};
#ifndef __cplusplus
/**
* @brief Structure initializer for spi_config from devicetree
*
* This helper macro expands to a static initializer for a <tt>struct
* spi_config</tt> by reading the relevant @p frequency, @p slave, and
* @p cs data from the devicetree.
*
* Important: the @p cs field is initialized using
* SPI_CS_CONTROL_PTR_DT(). The @p gpio_dev value pointed to by this
* structure must be checked using device_is_ready() before use.
*
* This macro is not available in C++.
*
* @param node_id Devicetree node identifier for the SPI device whose
* struct spi_config to create an initializer for
* @param operation_ the desired @p operation field in the struct spi_config
* @param delay_ the desired @p delay field in the struct spi_config's
* spi_cs_control, if there is one
*/
#define SPI_CONFIG_DT(node_id, operation_, delay_) \
{ \
.frequency = DT_PROP(node_id, spi_max_frequency), \
.operation = (operation_), \
.slave = DT_REG_ADDR(node_id), \
.cs = COND_CODE_1( \
DT_SPI_DEV_HAS_CS_GPIOS(node_id), \
(SPI_CS_CONTROL_PTR_DT(node_id, delay_)), \
(NULL)), \
}
/**
* @brief Structure initializer for spi_config from devicetree instance
*
* This is equivalent to
* <tt>SPI_CONFIG_DT(DT_DRV_INST(inst), operation_, delay_)</tt>.
*
* This macro is not available in C++.
*
* @param inst Devicetree instance number
* @param operation_ the desired @p operation field in the struct spi_config
* @param delay_ the desired @p delay field in the struct spi_config's
* spi_cs_control, if there is one
*/
#define SPI_CONFIG_DT_INST(inst, operation_, delay_) \
SPI_CONFIG_DT(DT_DRV_INST(inst), operation_, delay_)
#endif
/**
* @brief Complete SPI DT information
*
* @param bus is the SPI bus
* @param config is the slave specific configuration
*/
struct spi_dt_spec {
const struct device *bus;
struct spi_config config;
};
#ifndef __cplusplus
/**
* @brief Structure initializer for spi_dt_spec from devicetree
*
* This helper macro expands to a static initializer for a <tt>struct
* spi_dt_spec</tt> by reading the relevant bus, frequency, slave, and cs
* data from the devicetree.
*
* Important: multiple fields are automatically constructed by this macro
* which must be checked before use. @ref spi_is_ready performs the required
* @ref device_is_ready checks.
*
* This macro is not available in C++.
*
* @param node_id Devicetree node identifier for the SPI device whose
* struct spi_dt_spec to create an initializer for
* @param operation_ the desired @p operation field in the struct spi_config
* @param delay_ the desired @p delay field in the struct spi_config's
* spi_cs_control, if there is one
*/
#define SPI_DT_SPEC_GET(node_id, operation_, delay_) \
{ \
.bus = DEVICE_DT_GET(DT_BUS(node_id)), \
.config = SPI_CONFIG_DT(node_id, operation_, delay_) \
}
/**
* @brief Structure initializer for spi_dt_spec from devicetree instance
*
* This is equivalent to
* <tt>SPI_DT_SPEC_GET(DT_DRV_INST(inst), operation_, delay_)</tt>.
*
* This macro is not available in C++.
*
* @param inst Devicetree instance number
* @param operation_ the desired @p operation field in the struct spi_config
* @param delay_ the desired @p delay field in the struct spi_config's
* spi_cs_control, if there is one
*/
#define SPI_DT_SPEC_INST_GET(inst, operation_, delay_) \
SPI_DT_SPEC_GET(DT_DRV_INST(inst), operation_, delay_)
#endif
/**
* @brief SPI buffer structure
*
* @param buf is a valid pointer on a data buffer, or NULL otherwise.
* @param len is the length of the buffer or, if buf is NULL, will be the
* length which as to be sent as dummy bytes (as TX buffer) or
* the length of bytes that should be skipped (as RX buffer).
*/
struct spi_buf {
void *buf;
size_t len;
};
/**
* @brief SPI buffer array structure
*
* @param buffers is a valid pointer on an array of spi_buf, or NULL.
* @param count is the length of the array pointed by buffers.
*/
struct spi_buf_set {
const struct spi_buf *buffers;
size_t count;
};
/**
* @typedef spi_api_io
* @brief Callback API for I/O
* See spi_transceive() for argument descriptions
*/
typedef int (*spi_api_io)(const struct device *dev,
const struct spi_config *config,
const struct spi_buf_set *tx_bufs,
const struct spi_buf_set *rx_bufs);
/**
* @typedef spi_api_io
* @brief Callback API for asynchronous I/O
* See spi_transceive_async() for argument descriptions
*/
typedef int (*spi_api_io_async)(const struct device *dev,
const struct spi_config *config,
const struct spi_buf_set *tx_bufs,
const struct spi_buf_set *rx_bufs,
struct k_poll_signal *async);
/**
* @typedef spi_api_release
* @brief Callback API for unlocking SPI device.
* See spi_release() for argument descriptions
*/
typedef int (*spi_api_release)(const struct device *dev,
const struct spi_config *config);
/**
* @brief SPI driver API
* This is the mandatory API any SPI driver needs to expose.
*/
__subsystem struct spi_driver_api {
spi_api_io transceive;
#ifdef CONFIG_SPI_ASYNC
spi_api_io_async transceive_async;
#endif /* CONFIG_SPI_ASYNC */
spi_api_release release;
};
/**
* @brief Validate that SPI bus is ready.
*
* @param spec SPI specification from devicetree
*
* @retval true if the SPI bus is ready for use.
* @retval false if the SPI bus is not ready for use.
*/
static inline bool spi_is_ready(const struct spi_dt_spec *spec)
{
/* Validate bus is ready */
if (!device_is_ready(spec->bus)) {
return false;
}
/* Validate CS gpio port is ready, if it is used */
if (spec->config.cs &&
!device_is_ready(spec->config.cs->gpio_dev)) {
return false;
}
return true;
}
/**
* @brief Read/write the specified amount of data from the SPI driver.
*
* @note This function is synchronous.
*
* @param dev Pointer to the device structure for the driver instance
* @param config Pointer to a valid spi_config structure instance.
* Pointer-comparison may be used to detect changes from
* previous operations.
* @param tx_bufs Buffer array where data to be sent originates from,
* or NULL if none.
* @param rx_bufs Buffer array where data to be read will be written to,
* or NULL if none.
*
* @retval frames Positive number of frames received in slave mode.
* @retval 0 If successful in master mode.
* @retval -errno Negative errno code on failure.
*/
__syscall int spi_transceive(const struct device *dev,
const struct spi_config *config,
const struct spi_buf_set *tx_bufs,
const struct spi_buf_set *rx_bufs);
static inline int z_impl_spi_transceive(const struct device *dev,
const struct spi_config *config,
const struct spi_buf_set *tx_bufs,
const struct spi_buf_set *rx_bufs)
{
const struct spi_driver_api *api =
(const struct spi_driver_api *)dev->api;
return api->transceive(dev, config, tx_bufs, rx_bufs);
}
/**
* @brief Read/write data from an SPI bus specified in @p spi_dt_spec.
*
* This is equivalent to:
*
* spi_transceive(spec->bus, &spec->config, tx_bufs, rx_bufs);
*
* @param spec SPI specification from devicetree
* @param tx_bufs Buffer array where data to be sent originates from,
* or NULL if none.
* @param rx_bufs Buffer array where data to be read will be written to,
* or NULL if none.
*
* @return a value from spi_transceive().
*/
static inline int spi_transceive_dt(const struct spi_dt_spec *spec,
const struct spi_buf_set *tx_bufs,
const struct spi_buf_set *rx_bufs)
{
return spi_transceive(spec->bus, &spec->config, tx_bufs, rx_bufs);
}
/**
* @brief Read the specified amount of data from the SPI driver.
*
* @note This function is synchronous.
*
* @note This function is an helper function calling spi_transceive.
*
* @param dev Pointer to the device structure for the driver instance
* @param config Pointer to a valid spi_config structure instance.
* Pointer-comparison may be used to detect changes from
* previous operations.
* @param rx_bufs Buffer array where data to be read will be written to.
*
* @retval 0 If successful.
* @retval -errno Negative errno code on failure.
*/
static inline int spi_read(const struct device *dev,
const struct spi_config *config,
const struct spi_buf_set *rx_bufs)
{
return spi_transceive(dev, config, NULL, rx_bufs);
}
/**
* @brief Read data from a SPI bus specified in @p spi_dt_spec.
*
* This is equivalent to:
*
* spi_read(spec->bus, &spec->config, rx_bufs);
*
* @param spec SPI specification from devicetree
* @param rx_bufs Buffer array where data to be read will be written to.
*
* @return a value from spi_read().
*/
static inline int spi_read_dt(const struct spi_dt_spec *spec,
const struct spi_buf_set *rx_bufs)
{
return spi_read(spec->bus, &spec->config, rx_bufs);
}
/**
* @brief Write the specified amount of data from the SPI driver.
*
* @note This function is synchronous.
*
* @note This function is an helper function calling spi_transceive.
*
* @param dev Pointer to the device structure for the driver instance
* @param config Pointer to a valid spi_config structure instance.
* Pointer-comparison may be used to detect changes from
* previous operations.
* @param tx_bufs Buffer array where data to be sent originates from.
*
* @retval 0 If successful.
* @retval -errno Negative errno code on failure.
*/
static inline int spi_write(const struct device *dev,
const struct spi_config *config,
const struct spi_buf_set *tx_bufs)
{
return spi_transceive(dev, config, tx_bufs, NULL);
}
/**
* @brief Write data to a SPI bus specified in @p spi_dt_spec.
*
* This is equivalent to:
*
* spi_write(spec->bus, &spec->config, tx_bufs);
*
* @param spec SPI specification from devicetree
* @param tx_bufs Buffer array where data to be sent originates from.
*
* @return a value from spi_write().
*/
static inline int spi_write_dt(const struct spi_dt_spec *spec,
const struct spi_buf_set *tx_bufs)
{
return spi_write(spec->bus, &spec->config, tx_bufs);
}
/* Doxygen defines this so documentation is generated. */
#ifdef CONFIG_SPI_ASYNC
/**
* @brief Read/write the specified amount of data from the SPI driver.
*
* @note This function is asynchronous.
*
* @note This function is available only if @kconfig{CONFIG_SPI_ASYNC}
* is selected.
*
* @param dev Pointer to the device structure for the driver instance
* @param config Pointer to a valid spi_config structure instance.
* Pointer-comparison may be used to detect changes from
* previous operations.
* @param tx_bufs Buffer array where data to be sent originates from,
* or NULL if none.
* @param rx_bufs Buffer array where data to be read will be written to,
* or NULL if none.
* @param async A pointer to a valid and ready to be signaled
* struct k_poll_signal. (Note: if NULL this function will not
* notify the end of the transaction, and whether it went
* successfully or not).
*
* @retval frames Positive number of frames received in slave mode.
* @retval 0 If successful in master mode.
* @retval -errno Negative errno code on failure.
*/
static inline int spi_transceive_async(const struct device *dev,
const struct spi_config *config,
const struct spi_buf_set *tx_bufs,
const struct spi_buf_set *rx_bufs,
struct k_poll_signal *async)
{
const struct spi_driver_api *api =
(const struct spi_driver_api *)dev->api;
return api->transceive_async(dev, config, tx_bufs, rx_bufs, async);
}
/**
* @brief Read the specified amount of data from the SPI driver.
*
* @note This function is asynchronous.
*
* @note This function is an helper function calling spi_transceive_async.
*
* @note This function is available only if @kconfig{CONFIG_SPI_ASYNC}
* is selected.
*
* @param dev Pointer to the device structure for the driver instance
* @param config Pointer to a valid spi_config structure instance.
* Pointer-comparison may be used to detect changes from
* previous operations.
* @param rx_bufs Buffer array where data to be read will be written to.
* @param async A pointer to a valid and ready to be signaled
* struct k_poll_signal. (Note: if NULL this function will not
* notify the end of the transaction, and whether it went
* successfully or not).
*
* @retval 0 If successful
* @retval -errno Negative errno code on failure.
*/
static inline int spi_read_async(const struct device *dev,
const struct spi_config *config,
const struct spi_buf_set *rx_bufs,
struct k_poll_signal *async)
{
return spi_transceive_async(dev, config, NULL, rx_bufs, async);
}
/**
* @brief Write the specified amount of data from the SPI driver.
*
* @note This function is asynchronous.
*
* @note This function is an helper function calling spi_transceive_async.
*
* @note This function is available only if @kconfig{CONFIG_SPI_ASYNC}
* is selected.
*
* @param dev Pointer to the device structure for the driver instance
* @param config Pointer to a valid spi_config structure instance.
* Pointer-comparison may be used to detect changes from
* previous operations.
* @param tx_bufs Buffer array where data to be sent originates from.
* @param async A pointer to a valid and ready to be signaled
* struct k_poll_signal. (Note: if NULL this function will not
* notify the end of the transaction, and whether it went
* successfully or not).
*
* @retval 0 If successful.
* @retval -errno Negative errno code on failure.
*/
static inline int spi_write_async(const struct device *dev,
const struct spi_config *config,
const struct spi_buf_set *tx_bufs,
struct k_poll_signal *async)
{
return spi_transceive_async(dev, config, tx_bufs, NULL, async);
}
#endif /* CONFIG_SPI_ASYNC */
/**
* @brief Release the SPI device locked on by the current config
*
* Note: This synchronous function is used to release the lock on the SPI
* device that was kept if, and if only, given config parameter was
* the last one to be used (in any of the above functions) and if
* it has the SPI_LOCK_ON bit set into its operation bits field.
* This can be used if the caller needs to keep its hand on the SPI
* device for consecutive transactions.
*
* @param dev Pointer to the device structure for the driver instance
* @param config Pointer to a valid spi_config structure instance.
* Pointer-comparison may be used to detect changes from
* previous operations.
*
* @retval 0 If successful.
* @retval -errno Negative errno code on failure.
*/
__syscall int spi_release(const struct device *dev,
const struct spi_config *config);
static inline int z_impl_spi_release(const struct device *dev,
const struct spi_config *config)
{
const struct spi_driver_api *api =
(const struct spi_driver_api *)dev->api;
return api->release(dev, config);
}
/**
* @brief Release the SPI device specified in @p spi_dt_spec.
*
* This is equivalent to:
*
* spi_release(spec->bus, &spec->config);
*
* @param spec SPI specification from devicetree
*
* @return a value from spi_release().
*/
static inline int spi_release_dt(const struct spi_dt_spec *spec)
{
return spi_release(spec->bus, &spec->config);
}
#ifdef __cplusplus
}
#endif
/**
* @}
*/
#include <syscalls/spi.h>
#endif /* ZEPHYR_INCLUDE_DRIVERS_SPI_H_ */