michaelh/zephyr
1
0
Fork 0
Code Releases Activity

spi: introduce struct spi_dt_spec

Browse source 
Introduces the `struct spi_dt_spec` type, which contains the complete
SPI bus information derived from devicetree. It serves the same purpose
as `struct gpio_dt_spec` in that it can be constructed automatically in
`DEVICE_DT_INST_DEFINE` macros and provided as a single handle to SPI
API calls. Includes a single function, `spi_is_ready` that validates all
SPI bus dependencies are ready.

Signed-off-by: Jordan Yates <jordan.yates@data61.csiro.au>
This commit is contained in:
Jordan Yates 2021-06-23 21:46:15 +10:00 • committed by Anas Nashif
commit dcc04d9abd
1 changed files with 76 additions and 0 deletions
Download patch file Download diff file Expand all files Collapse all files

76
include/drivers/spi.h
View file

@ -297,6 +297,60 @@ struct spi_config {
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
*
@ -363,6 +417,28 @@ __subsystem struct spi_driver_api {
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.
*