kopia lustrzana https://github.com/espressif/esp-idf
411 wiersze
24 KiB
C
411 wiersze
24 KiB
C
/*
|
|
* SPDX-FileCopyrightText: 2010-2021 Espressif Systems (Shanghai) CO LTD
|
|
*
|
|
* SPDX-License-Identifier: Apache-2.0
|
|
*/
|
|
|
|
#pragma once
|
|
|
|
#include "esp_err.h"
|
|
#include "freertos/FreeRTOS.h"
|
|
#include "hal/spi_types.h"
|
|
//for spi_bus_initialization functions. to be back-compatible
|
|
#include "driver/spi_common.h"
|
|
#include "soc/soc_caps.h"
|
|
|
|
/**
|
|
* @brief SPI common used frequency (in Hz)
|
|
* @note SPI peripheral only has an integer divider, and the default clock source can be different on other targets,
|
|
* so the actual frequency may be slightly different from the desired frequency.
|
|
*/
|
|
#define SPI_MASTER_FREQ_8M (80 * 1000 * 1000 / 10) ///< 8MHz
|
|
#define SPI_MASTER_FREQ_9M (80 * 1000 * 1000 / 9) ///< 8.89MHz
|
|
#define SPI_MASTER_FREQ_10M (80 * 1000 * 1000 / 8) ///< 10MHz
|
|
#define SPI_MASTER_FREQ_11M (80 * 1000 * 1000 / 7) ///< 11.43MHz
|
|
#define SPI_MASTER_FREQ_13M (80 * 1000 * 1000 / 6) ///< 13.33MHz
|
|
#define SPI_MASTER_FREQ_16M (80 * 1000 * 1000 / 5) ///< 16MHz
|
|
#define SPI_MASTER_FREQ_20M (80 * 1000 * 1000 / 4) ///< 20MHz
|
|
#define SPI_MASTER_FREQ_26M (80 * 1000 * 1000 / 3) ///< 26.67MHz
|
|
#define SPI_MASTER_FREQ_40M (80 * 1000 * 1000 / 2) ///< 40MHz
|
|
#define SPI_MASTER_FREQ_80M (80 * 1000 * 1000 / 1) ///< 80MHz
|
|
|
|
#ifdef __cplusplus
|
|
extern "C"
|
|
{
|
|
#endif
|
|
|
|
#define SPI_DEVICE_TXBIT_LSBFIRST (1<<0) ///< Transmit command/address/data LSB first instead of the default MSB first
|
|
#define SPI_DEVICE_RXBIT_LSBFIRST (1<<1) ///< Receive data LSB first instead of the default MSB first
|
|
#define SPI_DEVICE_BIT_LSBFIRST (SPI_DEVICE_TXBIT_LSBFIRST|SPI_DEVICE_RXBIT_LSBFIRST) ///< Transmit and receive LSB first
|
|
#define SPI_DEVICE_3WIRE (1<<2) ///< Use MOSI (=spid) for both sending and receiving data
|
|
#define SPI_DEVICE_POSITIVE_CS (1<<3) ///< Make CS positive during a transaction instead of negative
|
|
#define SPI_DEVICE_HALFDUPLEX (1<<4) ///< Transmit data before receiving it, instead of simultaneously
|
|
#define SPI_DEVICE_CLK_AS_CS (1<<5) ///< Output clock on CS line if CS is active
|
|
/** There are timing issue when reading at high frequency (the frequency is related to whether iomux pins are used, valid time after slave sees the clock).
|
|
* - In half-duplex mode, the driver automatically inserts dummy bits before reading phase to fix the timing issue. Set this flag to disable this feature.
|
|
* - In full-duplex mode, however, the hardware cannot use dummy bits, so there is no way to prevent data being read from getting corrupted.
|
|
* Set this flag to confirm that you're going to work with output only, or read without dummy bits at your own risk.
|
|
*/
|
|
#define SPI_DEVICE_NO_DUMMY (1<<6)
|
|
#define SPI_DEVICE_DDRCLK (1<<7)
|
|
#define SPI_DEVICE_NO_RETURN_RESULT (1<<8) ///< Don't return the descriptor to the host on completion (use post_cb to notify instead)
|
|
|
|
/** @cond */
|
|
typedef struct spi_transaction_t spi_transaction_t;
|
|
/** @endcond */
|
|
typedef void(*transaction_cb_t)(spi_transaction_t *trans);
|
|
|
|
/**
|
|
* @brief This is a configuration for a SPI slave device that is connected to one of the SPI buses.
|
|
*/
|
|
typedef struct {
|
|
uint8_t command_bits; ///< Default amount of bits in command phase (0-16), used when ``SPI_TRANS_VARIABLE_CMD`` is not used, otherwise ignored.
|
|
uint8_t address_bits; ///< Default amount of bits in address phase (0-64), used when ``SPI_TRANS_VARIABLE_ADDR`` is not used, otherwise ignored.
|
|
uint8_t dummy_bits; ///< Amount of dummy bits to insert between address and data phase
|
|
uint8_t mode; /**< SPI mode, representing a pair of (CPOL, CPHA) configuration:
|
|
- 0: (0, 0)
|
|
- 1: (0, 1)
|
|
- 2: (1, 0)
|
|
- 3: (1, 1)
|
|
*/
|
|
spi_clock_source_t clock_source;///< Select SPI clock source, `SPI_CLK_SRC_DEFAULT` by default.
|
|
uint16_t duty_cycle_pos; ///< Duty cycle of positive clock, in 1/256th increments (128 = 50%/50% duty). Setting this to 0 (=not setting it) is equivalent to setting this to 128.
|
|
uint16_t cs_ena_pretrans; ///< Amount of SPI bit-cycles the cs should be activated before the transmission (0-16). This only works on half-duplex transactions.
|
|
uint8_t cs_ena_posttrans; ///< Amount of SPI bit-cycles the cs should stay active after the transmission (0-16)
|
|
int clock_speed_hz; ///< SPI clock speed in Hz. Derived from `clock_source`.
|
|
int input_delay_ns; /**< Maximum data valid time of slave. The time required between SCLK and MISO
|
|
valid, including the possible clock delay from slave to master. The driver uses this value to give an extra
|
|
delay before the MISO is ready on the line. Leave at 0 unless you know you need a delay. For better timing
|
|
performance at high frequency (over 8MHz), it's suggest to have the right value.
|
|
*/
|
|
int spics_io_num; ///< CS GPIO pin for this device, or -1 if not used
|
|
uint32_t flags; ///< Bitwise OR of SPI_DEVICE_* flags
|
|
int queue_size; ///< Transaction queue size. This sets how many transactions can be 'in the air' (queued using spi_device_queue_trans but not yet finished using spi_device_get_trans_result) at the same time
|
|
transaction_cb_t pre_cb; /**< Callback to be called before a transmission is started.
|
|
*
|
|
* This callback is called within interrupt
|
|
* context should be in IRAM for best
|
|
* performance, see "Transferring Speed"
|
|
* section in the SPI Master documentation for
|
|
* full details. If not, the callback may crash
|
|
* during flash operation when the driver is
|
|
* initialized with ESP_INTR_FLAG_IRAM.
|
|
*/
|
|
transaction_cb_t post_cb; /**< Callback to be called after a transmission has completed.
|
|
*
|
|
* This callback is called within interrupt
|
|
* context should be in IRAM for best
|
|
* performance, see "Transferring Speed"
|
|
* section in the SPI Master documentation for
|
|
* full details. If not, the callback may crash
|
|
* during flash operation when the driver is
|
|
* initialized with ESP_INTR_FLAG_IRAM.
|
|
*/
|
|
} spi_device_interface_config_t;
|
|
|
|
#define SPI_TRANS_MODE_DIO (1<<0) ///< Transmit/receive data in 2-bit mode
|
|
#define SPI_TRANS_MODE_QIO (1<<1) ///< Transmit/receive data in 4-bit mode
|
|
#define SPI_TRANS_USE_RXDATA (1<<2) ///< Receive into rx_data member of spi_transaction_t instead into memory at rx_buffer.
|
|
#define SPI_TRANS_USE_TXDATA (1<<3) ///< Transmit tx_data member of spi_transaction_t instead of data at tx_buffer. Do not set tx_buffer when using this.
|
|
#define SPI_TRANS_MODE_DIOQIO_ADDR (1<<4) ///< Also transmit address in mode selected by SPI_MODE_DIO/SPI_MODE_QIO
|
|
#define SPI_TRANS_VARIABLE_CMD (1<<5) ///< Use the ``command_bits`` in ``spi_transaction_ext_t`` rather than default value in ``spi_device_interface_config_t``.
|
|
#define SPI_TRANS_VARIABLE_ADDR (1<<6) ///< Use the ``address_bits`` in ``spi_transaction_ext_t`` rather than default value in ``spi_device_interface_config_t``.
|
|
#define SPI_TRANS_VARIABLE_DUMMY (1<<7) ///< Use the ``dummy_bits`` in ``spi_transaction_ext_t`` rather than default value in ``spi_device_interface_config_t``.
|
|
#define SPI_TRANS_CS_KEEP_ACTIVE (1<<8) ///< Keep CS active after data transfer
|
|
#define SPI_TRANS_MULTILINE_CMD (1<<9) ///< The data lines used at command phase is the same as data phase (otherwise, only one data line is used at command phase)
|
|
#define SPI_TRANS_MODE_OCT (1<<10) ///< Transmit/receive data in 8-bit mode
|
|
#define SPI_TRANS_MULTILINE_ADDR SPI_TRANS_MODE_DIOQIO_ADDR ///< The data lines used at address phase is the same as data phase (otherwise, only one data line is used at address phase)
|
|
#define SPI_TRANS_DMA_BUFFER_ALIGN_MANUAL (1<<11) ///< By default driver will automatically re-alloc dma buffer if it doesn't meet hardware alignment or dma_capable requirements, this flag is for you to disable this feature, you will need to take care of the alignment otherwise driver will return you error ESP_ERR_INVALID_ARG
|
|
|
|
/**
|
|
* This structure describes one SPI transaction. The descriptor should not be modified until the transaction finishes.
|
|
*/
|
|
struct spi_transaction_t {
|
|
uint32_t flags; ///< Bitwise OR of SPI_TRANS_* flags
|
|
uint16_t cmd; /**< Command data, of which the length is set in the ``command_bits`` of spi_device_interface_config_t.
|
|
*
|
|
* <b>NOTE: this field, used to be "command" in ESP-IDF 2.1 and before, is re-written to be used in a new way in ESP-IDF 3.0.</b>
|
|
*
|
|
* Example: write 0x0123 and command_bits=12 to send command 0x12, 0x3_ (in previous version, you may have to write 0x3_12).
|
|
*/
|
|
uint64_t addr; /**< Address data, of which the length is set in the ``address_bits`` of spi_device_interface_config_t.
|
|
*
|
|
* <b>NOTE: this field, used to be "address" in ESP-IDF 2.1 and before, is re-written to be used in a new way in ESP-IDF3.0.</b>
|
|
*
|
|
* Example: write 0x123400 and address_bits=24 to send address of 0x12, 0x34, 0x00 (in previous version, you may have to write 0x12340000).
|
|
*/
|
|
size_t length; ///< Total data length, in bits
|
|
size_t rxlength; ///< Total data length received, should be not greater than ``length`` in full-duplex mode (0 defaults this to the value of ``length``).
|
|
void *user; ///< User-defined variable. Can be used to store eg transaction ID.
|
|
union {
|
|
const void *tx_buffer; ///< Pointer to transmit buffer, or NULL for no MOSI phase
|
|
uint8_t tx_data[4]; ///< If SPI_TRANS_USE_TXDATA is set, data set here is sent directly from this variable.
|
|
};
|
|
union {
|
|
void *rx_buffer; ///< Pointer to receive buffer, or NULL for no MISO phase. Written by 4 bytes-unit if DMA is used.
|
|
uint8_t rx_data[4]; ///< If SPI_TRANS_USE_RXDATA is set, data is received directly to this variable
|
|
};
|
|
} ; //the rx data should start from a 32-bit aligned address to get around dma issue.
|
|
|
|
/**
|
|
* This struct is for SPI transactions which may change their address and command length.
|
|
* Please do set the flags in base to ``SPI_TRANS_VARIABLE_CMD_ADR`` to use the bit length here.
|
|
*/
|
|
typedef struct {
|
|
struct spi_transaction_t base; ///< Transaction data, so that pointer to spi_transaction_t can be converted into spi_transaction_ext_t
|
|
uint8_t command_bits; ///< The command length in this transaction, in bits.
|
|
uint8_t address_bits; ///< The address length in this transaction, in bits.
|
|
uint8_t dummy_bits; ///< The dummy length in this transaction, in bits.
|
|
} spi_transaction_ext_t ;
|
|
|
|
typedef struct spi_device_t *spi_device_handle_t; ///< Handle for a device on a SPI bus
|
|
/**
|
|
* @brief Allocate a device on a SPI bus
|
|
*
|
|
* This initializes the internal structures for a device, plus allocates a CS pin on the indicated SPI master
|
|
* peripheral and routes it to the indicated GPIO. All SPI master devices have three CS pins and can thus control
|
|
* up to three devices.
|
|
*
|
|
* @note On ESP32, due to the delay of GPIO matrix, the maximum frequency SPI Master can correctly samples the slave's
|
|
* output is lower than the case using IOMUX. Typical maximum frequency communicating with an ideal slave
|
|
* without data output delay: 80MHz (IOMUX pins) and 26MHz (GPIO matrix pins). With the help of extra dummy
|
|
* cycles in half-duplex mode, the delay can be compensated by setting `input_delay_ns` in `dev_config` structure
|
|
* correctly.
|
|
*
|
|
* There's no notable delay on chips other than ESP32.
|
|
*
|
|
* @param host_id SPI peripheral to allocate device on
|
|
* @param dev_config SPI interface protocol config for the device
|
|
* @param handle Pointer to variable to hold the device handle
|
|
* @return
|
|
* - ESP_ERR_INVALID_ARG if parameter is invalid or configuration combination is not supported (e.g.
|
|
* `dev_config->post_cb` isn't set while flag `SPI_DEVICE_NO_RETURN_RESULT` is enabled)
|
|
* - ESP_ERR_INVALID_STATE if selected clock source is unavailable or spi bus not initialized
|
|
* - ESP_ERR_NOT_FOUND if host doesn't have any free CS slots
|
|
* - ESP_ERR_NO_MEM if out of memory
|
|
* - ESP_OK on success
|
|
*/
|
|
esp_err_t spi_bus_add_device(spi_host_device_t host_id, const spi_device_interface_config_t *dev_config, spi_device_handle_t *handle);
|
|
|
|
/**
|
|
* @brief Remove a device from the SPI bus
|
|
*
|
|
* @param handle Device handle to free
|
|
* @return
|
|
* - ESP_ERR_INVALID_ARG if parameter is invalid
|
|
* - ESP_ERR_INVALID_STATE if device already is freed
|
|
* - ESP_OK on success
|
|
*/
|
|
esp_err_t spi_bus_remove_device(spi_device_handle_t handle);
|
|
|
|
/**
|
|
* @brief Queue a SPI transaction for interrupt transaction execution. Get the result by ``spi_device_get_trans_result``.
|
|
*
|
|
* @note Normally a device cannot start (queue) polling and interrupt
|
|
* transactions simultaneously.
|
|
*
|
|
* @param handle Device handle obtained using spi_host_add_dev
|
|
* @param trans_desc Description of transaction to execute
|
|
* @param ticks_to_wait Ticks to wait until there's room in the queue; use portMAX_DELAY to
|
|
* never time out.
|
|
* @return
|
|
* - ESP_ERR_INVALID_ARG if parameter is invalid. This can happen if SPI_TRANS_CS_KEEP_ACTIVE flag is specified while
|
|
* the bus was not acquired (`spi_device_acquire_bus()` should be called first)
|
|
* or set flag SPI_TRANS_DMA_BUFFER_ALIGN_MANUAL but tx or rx buffer not DMA-capable, or addr&len not align to cache line size
|
|
* - ESP_ERR_TIMEOUT if there was no room in the queue before ticks_to_wait expired
|
|
* - ESP_ERR_NO_MEM if allocating DMA-capable temporary buffer failed
|
|
* - ESP_ERR_INVALID_STATE if previous transactions are not finished
|
|
* - ESP_OK on success
|
|
*/
|
|
esp_err_t spi_device_queue_trans(spi_device_handle_t handle, spi_transaction_t *trans_desc, TickType_t ticks_to_wait);
|
|
|
|
/**
|
|
* @brief Get the result of a SPI transaction queued earlier by ``spi_device_queue_trans``.
|
|
*
|
|
* This routine will wait until a transaction to the given device
|
|
* succesfully completed. It will then return the description of the
|
|
* completed transaction so software can inspect the result and e.g. free the memory or
|
|
* re-use the buffers.
|
|
*
|
|
* @param handle Device handle obtained using spi_host_add_dev
|
|
* @param trans_desc Pointer to variable able to contain a pointer to the description of the transaction
|
|
that is executed. The descriptor should not be modified until the descriptor is returned by
|
|
spi_device_get_trans_result.
|
|
* @param ticks_to_wait Ticks to wait until there's a returned item; use portMAX_DELAY to never time
|
|
out.
|
|
* @return
|
|
* - ESP_ERR_INVALID_ARG if parameter is invalid
|
|
* - ESP_ERR_NOT_SUPPORTED if flag `SPI_DEVICE_NO_RETURN_RESULT` is set
|
|
* - ESP_ERR_TIMEOUT if there was no completed transaction before ticks_to_wait expired
|
|
* - ESP_OK on success
|
|
*/
|
|
esp_err_t spi_device_get_trans_result(spi_device_handle_t handle, spi_transaction_t **trans_desc, TickType_t ticks_to_wait);
|
|
|
|
/**
|
|
* @brief Send a SPI transaction, wait for it to complete, and return the result
|
|
*
|
|
* This function is the equivalent of calling spi_device_queue_trans() followed by spi_device_get_trans_result().
|
|
* Do not use this when there is still a transaction separately queued (started) from spi_device_queue_trans() or polling_start/transmit that hasn't been finalized.
|
|
*
|
|
* @note This function is not thread safe when multiple tasks access the same SPI device.
|
|
* Normally a device cannot start (queue) polling and interrupt
|
|
* transactions simutanuously.
|
|
*
|
|
* @param handle Device handle obtained using spi_host_add_dev
|
|
* @param trans_desc Description of transaction to execute
|
|
* @return
|
|
* - ESP_ERR_INVALID_ARG if parameter is invalid
|
|
* - ESP_OK on success
|
|
*/
|
|
esp_err_t spi_device_transmit(spi_device_handle_t handle, spi_transaction_t *trans_desc);
|
|
|
|
/**
|
|
* @brief Immediately start a polling transaction.
|
|
*
|
|
* @note Normally a device cannot start (queue) polling and interrupt
|
|
* transactions simutanuously. Moreover, a device cannot start a new polling
|
|
* transaction if another polling transaction is not finished.
|
|
*
|
|
* @param handle Device handle obtained using spi_host_add_dev
|
|
* @param trans_desc Description of transaction to execute
|
|
* @param ticks_to_wait Ticks to wait until there's room in the queue;
|
|
* currently only portMAX_DELAY is supported.
|
|
*
|
|
* @return
|
|
* - ESP_ERR_INVALID_ARG if parameter is invalid. This can happen if SPI_TRANS_CS_KEEP_ACTIVE flag is specified while
|
|
* the bus was not acquired (`spi_device_acquire_bus()` should be called first)
|
|
* or set flag SPI_TRANS_DMA_BUFFER_ALIGN_MANUAL but tx or rx buffer not DMA-capable, or addr&len not align to cache line size
|
|
* - ESP_ERR_TIMEOUT if the device cannot get control of the bus before ``ticks_to_wait`` expired
|
|
* - ESP_ERR_NO_MEM if allocating DMA-capable temporary buffer failed
|
|
* - ESP_ERR_INVALID_STATE if previous transactions are not finished
|
|
* - ESP_OK on success
|
|
*/
|
|
esp_err_t spi_device_polling_start(spi_device_handle_t handle, spi_transaction_t *trans_desc, TickType_t ticks_to_wait);
|
|
|
|
/**
|
|
* @brief Poll until the polling transaction ends.
|
|
*
|
|
* This routine will not return until the transaction to the given device has
|
|
* succesfully completed. The task is not blocked, but actively busy-spins for
|
|
* the transaction to be completed.
|
|
*
|
|
* @param handle Device handle obtained using spi_host_add_dev
|
|
* @param ticks_to_wait Ticks to wait until there's a returned item; use portMAX_DELAY to never time
|
|
out.
|
|
* @return
|
|
* - ESP_ERR_INVALID_ARG if parameter is invalid
|
|
* - ESP_ERR_TIMEOUT if the transaction cannot finish before ticks_to_wait expired
|
|
* - ESP_OK on success
|
|
*/
|
|
esp_err_t spi_device_polling_end(spi_device_handle_t handle, TickType_t ticks_to_wait);
|
|
|
|
/**
|
|
* @brief Send a polling transaction, wait for it to complete, and return the result
|
|
*
|
|
* This function is the equivalent of calling spi_device_polling_start() followed by spi_device_polling_end().
|
|
* Do not use this when there is still a transaction that hasn't been finalized.
|
|
*
|
|
* @note This function is not thread safe when multiple tasks access the same SPI device.
|
|
* Normally a device cannot start (queue) polling and interrupt
|
|
* transactions simutanuously.
|
|
*
|
|
* @param handle Device handle obtained using spi_host_add_dev
|
|
* @param trans_desc Description of transaction to execute
|
|
* @return
|
|
* - ESP_ERR_INVALID_ARG if parameter is invalid
|
|
* - ESP_ERR_TIMEOUT if the device cannot get control of the bus
|
|
* - ESP_ERR_NO_MEM if allocating DMA-capable temporary buffer failed
|
|
* - ESP_ERR_INVALID_STATE if previous transactions of same device are not finished
|
|
* - ESP_OK on success
|
|
*/
|
|
esp_err_t spi_device_polling_transmit(spi_device_handle_t handle, spi_transaction_t *trans_desc);
|
|
|
|
/**
|
|
* @brief Occupy the SPI bus for a device to do continuous transactions.
|
|
*
|
|
* Transactions to all other devices will be put off until ``spi_device_release_bus`` is called.
|
|
*
|
|
* @note The function will wait until all the existing transactions have been sent.
|
|
*
|
|
* @param device The device to occupy the bus.
|
|
* @param wait Time to wait before the the bus is occupied by the device. Currently MUST set to portMAX_DELAY.
|
|
*
|
|
* @return
|
|
* - ESP_ERR_INVALID_ARG : ``wait`` is not set to portMAX_DELAY.
|
|
* - ESP_OK : Success.
|
|
*/
|
|
esp_err_t spi_device_acquire_bus(spi_device_handle_t device, TickType_t wait);
|
|
|
|
/**
|
|
* @brief Release the SPI bus occupied by the device. All other devices can start sending transactions.
|
|
*
|
|
* @param dev The device to release the bus.
|
|
*/
|
|
void spi_device_release_bus(spi_device_handle_t dev);
|
|
|
|
/**
|
|
* @brief Calculate working frequency for specific device
|
|
*
|
|
* @param handle SPI device handle
|
|
* @param[out] freq_khz output parameter to hold calculated frequency in kHz
|
|
*
|
|
* @return
|
|
* - ESP_ERR_INVALID_ARG : ``handle`` or ``freq_khz`` parameter is NULL
|
|
* - ESP_OK : Success
|
|
*/
|
|
esp_err_t spi_device_get_actual_freq(spi_device_handle_t handle, int *freq_khz);
|
|
|
|
/**
|
|
* @brief Calculate the working frequency that is most close to desired frequency.
|
|
*
|
|
* @param fapb The frequency of apb clock, should be ``APB_CLK_FREQ``.
|
|
* @param hz Desired working frequency
|
|
* @param duty_cycle Duty cycle of the spi clock
|
|
*
|
|
* @return Actual working frequency that most fit.
|
|
*/
|
|
int spi_get_actual_clock(int fapb, int hz, int duty_cycle) __attribute__((deprecated("Please use spi_device_get_actual_freq instead")));
|
|
|
|
/**
|
|
* @brief Calculate the timing settings of specified frequency and settings.
|
|
*
|
|
* @param gpio_is_used True if using GPIO matrix, or False if iomux pins are used.
|
|
* @param input_delay_ns Input delay from SCLK launch edge to MISO data valid.
|
|
* @param eff_clk Effective clock frequency (in Hz) from `spi_get_actual_clock()`.
|
|
* @param dummy_o Address of dummy bits used output. Set to NULL if not needed.
|
|
* @param cycles_remain_o Address of cycles remaining (after dummy bits are used) output.
|
|
* - -1 If too many cycles remaining, suggest to compensate half a clock.
|
|
* - 0 If no remaining cycles or dummy bits are not used.
|
|
* - positive value: cycles suggest to compensate.
|
|
*
|
|
* @note If **dummy_o* is not zero, it means dummy bits should be applied in half duplex mode, and full duplex mode may not work.
|
|
*/
|
|
void spi_get_timing(bool gpio_is_used, int input_delay_ns, int eff_clk, int *dummy_o, int *cycles_remain_o);
|
|
|
|
/**
|
|
* @brief Get the frequency limit of current configurations.
|
|
* SPI master working at this limit is OK, while above the limit, full duplex mode and DMA will not work,
|
|
* and dummy bits will be aplied in the half duplex mode.
|
|
*
|
|
* @param gpio_is_used True if using GPIO matrix, or False if native pins are used.
|
|
* @param input_delay_ns Input delay from SCLK launch edge to MISO data valid.
|
|
* @return Frequency limit of current configurations.
|
|
*/
|
|
int spi_get_freq_limit(bool gpio_is_used, int input_delay_ns);
|
|
|
|
/**
|
|
* @brief Get max length (in bytes) of one transaction
|
|
*
|
|
* @param host_id SPI peripheral
|
|
* @param[out] max_bytes Max length of one transaction, in bytes
|
|
*
|
|
* @return
|
|
* - ESP_OK: On success
|
|
* - ESP_ERR_INVALID_ARG: Invalid argument
|
|
*/
|
|
esp_err_t spi_bus_get_max_transaction_len(spi_host_device_t host_id, size_t *max_bytes);
|
|
|
|
#ifdef __cplusplus
|
|
}
|
|
#endif
|