/**
* \file Hardware SPI master driver
*
* Part of esp-open-rtos
*
* \copyright Ruslan V. Uss, 2016
* BSD Licensed as described in the file LICENSE
*/
#ifndef _ESP_SPI_H_
#define _ESP_SPI_H_
#include <stdbool.h>
#include <stdint.h>
#include "esp/spi_regs.h"
#include "esp/clocks.h"
/**
* Macro for use with spi_init and spi_set_frequency_div.
* SPI frequency = 80000000 / divider / count
* dvider must be in 1..8192 and count in 1..64
*/
#define SPI_GET_FREQ_DIV(divider, count) (((count) << 16) | ((divider) & 0xffff))
/**
* Predefinded SPI frequency dividers
*/
#define SPI_FREQ_DIV_125K SPI_GET_FREQ_DIV(64, 10) ///< 125kHz
#define SPI_FREQ_DIV_250K SPI_GET_FREQ_DIV(32, 10) ///< 250kHz
#define SPI_FREQ_DIV_500K SPI_GET_FREQ_DIV(16, 10) ///< 500kHz
#define SPI_FREQ_DIV_1M SPI_GET_FREQ_DIV(8, 10) ///< 1MHz
#define SPI_FREQ_DIV_2M SPI_GET_FREQ_DIV(4, 10) ///< 2MHz
#define SPI_FREQ_DIV_4M SPI_GET_FREQ_DIV(2, 10) ///< 4MHz
#define SPI_FREQ_DIV_8M SPI_GET_FREQ_DIV(5, 2) ///< 8MHz
#define SPI_FREQ_DIV_10M SPI_GET_FREQ_DIV(4, 2) ///< 10MHz
#define SPI_FREQ_DIV_20M SPI_GET_FREQ_DIV(2, 2) ///< 20MHz
#define SPI_FREQ_DIV_40M SPI_GET_FREQ_DIV(1, 2) ///< 40MHz
#define SPI_FREQ_DIV_80M SPI_GET_FREQ_DIV(1, 1) ///< 80MHz
#ifdef __cplusplus
extern "C"
{
#endif
typedef enum _spi_mode_t {
SPI_MODE0 = 0, ///< CPOL = 0, CPHA = 0
SPI_MODE1, ///< CPOL = 0, CPHA = 1
SPI_MODE2, ///< CPOL = 1, CPHA = 0
SPI_MODE3 ///< CPOL = 1, CPHA = 1
} spi_mode_t;
typedef enum _spi_endianness_t {
SPI_LITTLE_ENDIAN = 0,
SPI_BIG_ENDIAN
} spi_endianness_t;
typedef enum _spi_word_size_t {
SPI_8BIT = 1, ///< 1 byte
SPI_16BIT = 2, ///< 2 bytes
SPI_32BIT = 4 ///< 4 bytes
} spi_word_size_t;
/**
* SPI bus settings
*/
typedef struct
{
spi_mode_t mode; ///< Bus mode
uint32_t freq_divider; ///< Bus frequency as a divider. See spi_init()
bool msb; ///< MSB first if true
spi_endianness_t endianness; ///< Bus byte order
bool minimal_pins; ///< Minimal set of pins if true. Spee spi_init()
} spi_settings_t;
/**
* \brief Initalize SPI bus
* Initalize specified SPI bus and setup appropriate pins:
* Bus 0:
* - MISO = GPIO 7
* - MOSI = GPIO 8
* - SCK = GPIO 6
* - CS0 = GPIO 11 (if minimal_pins is false)
* - HD = GPIO 9 (if minimal_pins is false)
* - WP = GPIO 10 (if minimal_pins is false)
* Bus 1:
* - MISO = GPIO 12
* - MOSI = GPIO 13
* - SCK = GPIO 14
* - CS0 = GPIO 15 (if minimal_pins is false)
* Note that system flash memory is on the bus 0!
* \param bus Bus ID: 0 - system, 1 - user
* \param mode Bus mode
* \param freq_divider SPI bus frequency divider, use SPI_GET_FREQ_DIV() or predefined value
* \param msb Bit order, MSB first if true
* \param endianness Byte order
* \param minimal_pins If true use the minimal set of pins: MISO, MOSI and SCK.
* \return false when error
*/
bool spi_init(uint8_t bus, spi_mode_t mode, uint32_t freq_divider, bool msb, spi_endianness_t endianness, bool minimal_pins);
/**
* \brief Initalize SPI bus
* spi_init() wrapper.
* Example:
*
* const spi_settings_t my_settings = {
* .mode = SPI_MODE0,
* .freq_divider = SPI_FREQ_DIV_4M,
* .msb = true,
* .endianness = SPI_LITTLE_ENDIAN,
* .minimal_pins = true
* }
* ....
* spi_settings_t old;
* spi_get_settings(1, &old); // save current settings
* //spi_init(1, SPI_MODE0, SPI_FREQ_DIV_4M, true, SPI_LITTLE_ENDIAN, true); // use own settings
* // or
* spi_set_settings(1, &my_settings);
* // some work with spi here
* ....
* spi_set_settings(1, &old); // restore saved settings
*
* \param s Pointer to the settings structure
* \return false when error
*/
static inline bool spi_set_settings(uint8_t bus, const spi_settings_t *s)
{
return spi_init(bus, s->mode, s->freq_divider, s->msb, s->endianness, s->minimal_pins);
}
/**
* \brief Get current settings of the SPI bus
* See spi_set_settings().
* \param bus Bus ID: 0 - system, 1 - user
* \param s Pointer to the structure that receives SPI bus settings
*/
void spi_get_settings(uint8_t bus, spi_settings_t *s);
/**
* \brief Set SPI bus mode
* \param bus Bus ID: 0 - system, 1 - user
* \param mode Bus mode
*/
void spi_set_mode(uint8_t bus, spi_mode_t mode);
/**
* \brief Get mode of the SPI bus
* \param bus Bus ID: 0 - system, 1 - user
* \return Bus mode
*/
spi_mode_t spi_get_mode(uint8_t bus);
/**
* \brief Set SPI bus frequency
* Examples:
*
* spi_set_frequency_div(1, SPI_FREQ_DIV_8M); // 8 MHz, predefined value
* ...
* spi_set_frequency_div(1, SPI_GET_FREQ_DIV(8, 10)); // divider = 8, count = 10,
* // frequency = 80000000 Hz / 8 / 10 = 1000000 Hz
*
* \param bus Bus ID: 0 - system, 1 - user
* \param divider Predivider of the system bus frequency (80MHz) in the 2 low
* bytes and period pulses count in the third byte. Please note that
* divider must be be in range 1..8192 and count in range 2..64. Use the
* macro SPI_GET_FREQ_DIV(divider, count) to get the correct parameter value.
*/
void spi_set_frequency_div(uint8_t bus, uint32_t divider);
/**
* \brief Get SPI bus frequency as a divider
* Example:
*
* uint32_t old_freq = spi_get_frequency_div(1);
* spi_set_frequency_div(1, SPI_FREQ_DIV_8M);
* ...
* spi_set_frequency_div(1, old_freq);
*
* \param bus Bus ID: 0 - system, 1 - user
* \return SPI frequency, as divider.
*/
inline uint32_t spi_get_frequency_div(uint8_t bus)
{
return (FIELD2VAL(SPI_CLOCK_DIV_PRE, SPI(bus).CLOCK) + 1) |
(FIELD2VAL(SPI_CLOCK_COUNT_NUM, SPI(bus).CLOCK) + 1);
}
/**
* \brief Get SPI bus frequency in Hz
* \param bus Bus ID: 0 - system, 1 - user
* \return SPI frequency, Hz
*/
inline uint32_t spi_get_frequency_hz(uint8_t bus)
{
return APB_CLK_FREQ /
(FIELD2VAL(SPI_CLOCK_DIV_PRE, SPI(bus).CLOCK) + 1) /
(FIELD2VAL(SPI_CLOCK_COUNT_NUM, SPI(bus).CLOCK) + 1);
}
/**
* \brief Set SPI bus bit order
* \param bus Bus ID: 0 - system, 1 - user
* \param msb Bit order, MSB first if true
*/
void spi_set_msb(uint8_t bus, bool msb);
/**
* \brief Get SPI bus bit order
* \param bus Bus ID: 0 - system, 1 - user
* \return msb Bit order, MSB first if true
*/
inline bool spi_get_msb(uint8_t bus)
{
return !(SPI(bus).CTRL0 & (SPI_CTRL0_WR_BIT_ORDER | SPI_CTRL0_RD_BIT_ORDER));
}
/**
* \brief Set SPI bus byte order
* \param bus Bus ID: 0 - system, 1 - user
* \param endianness Byte order
*/
void spi_set_endianness(uint8_t bus, spi_endianness_t endianness);
/**
* \brief Get SPI bus byte order
* \param bus Bus ID: 0 - system, 1 - user
* \return endianness Byte order
*/
inline spi_endianness_t spi_get_endianness(uint8_t bus)
{
return SPI(bus).USER0 & (SPI_USER0_WR_BYTE_ORDER | SPI_USER0_RD_BYTE_ORDER)
? SPI_BIG_ENDIAN
: SPI_LITTLE_ENDIAN;
}
/**
* \brief Transfer 8 bits over SPI
* \param bus Bus ID: 0 - system, 1 - user
* \param data Byte to send
* \return Received byte
*/
uint8_t spi_transfer_8(uint8_t bus, uint8_t data);
/**
* \brief Transfer 16 bits over SPI
* \param bus Bus ID: 0 - system, 1 - user
* \param data Word to send
* \return Received word
*/
uint16_t spi_transfer_16(uint8_t bus, uint16_t data);
/**
* \brief Transfer 32 bits over SPI
* \param bus Bus ID: 0 - system, 1 - user
* \param data dword to send
* \return Received dword
*/
uint32_t spi_transfer_32(uint8_t bus, uint32_t data);
/**
* \brief Transfer buffer of words over SPI
* Please note that the buffer size is in words, not in bytes!
* Example:
*
* const uint16_t out_buf[] = { 0xa0b0, 0xa1b1, 0xa2b2, 0xa3b3 };
* uint16_t in_buf[sizeof(out_buf)];
* spi_init(1, SPI_MODE1, SPI_FREQ_DIV_4M, true, SPI_BIG_ENDIAN, true);
* spi_transfer(1, out_buf, in_buf, sizeof(out_buf), SPI_16BIT); // len = 4 words * 2 bytes = 8 bytes
*
* \param bus Bus ID: 0 - system, 1 - user
* \param out_data Data to send.
* \param in_data Receive buffer. If NULL, received data will be lost.
* \param len Buffer size in words
* \param word_size Size of the word
* \return Transmitted/received words count
*/
size_t spi_transfer(uint8_t bus, const void *out_data, void *in_data, size_t len, spi_word_size_t word_size);
#ifdef __cplusplus
}
#endif
#endif /* _ESP_SPI_H_ */