j3d1/esp-open-rtos
1
0
Fork 0
Code Issues Pull requests Projects Releases Wiki Activity

Merge pull request #110 from UncleRus/core/spi

Browse source 
Hardware SPI driver
This commit is contained in:
Angus Gratton 2016-03-16 17:01:12 +11:00
commit b6132a480e
3 changed files with 454 additions and 0 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

245
core/esp_spi.c Normal file
View file

@ -0,0 +1,245 @@
/*
* ESP hardware SPI master driver
*
* Part of esp-open-rtos
* Copyright (c) Ruslan V. Uss, 2016
* BSD Licensed as described in the file LICENSE
*/
#include "esp/spi.h"
#include "esp/iomux.h"
#include "esp/gpio.h"
#include <string.h>
#define _SPI0_SCK_GPIO 6
#define _SPI0_MISO_GPIO 7
#define _SPI0_MOSI_GPIO 8
#define _SPI0_HD_GPIO 9
#define _SPI0_WP_GPIO 10
#define _SPI0_CS0_GPIO 11
#define _SPI1_MISO_GPIO 12
#define _SPI1_MOSI_GPIO 13
#define _SPI1_SCK_GPIO 14
#define _SPI1_CS0_GPIO 15
#define _SPI0_FUNC 1
#define _SPI1_FUNC 2
#define _SPI_BUF_SIZE 64
inline static void _set_pin_function(uint8_t pin, uint32_t function)
{
iomux_set_function(gpio_to_iomux(pin), function);
}
bool spi_init(uint8_t bus, spi_mode_t mode, uint32_t freq_divider, bool msb, spi_endianness_t endianness, bool minimal_pins)
{
switch (bus)
{
case 0:
_set_pin_function(_SPI0_MISO_GPIO, _SPI0_FUNC);
_set_pin_function(_SPI0_MOSI_GPIO, _SPI0_FUNC);
_set_pin_function(_SPI0_SCK_GPIO, _SPI0_FUNC);
if (!minimal_pins)
{
_set_pin_function(_SPI0_HD_GPIO, _SPI0_FUNC);
_set_pin_function(_SPI0_WP_GPIO, _SPI0_FUNC);
_set_pin_function(_SPI0_CS0_GPIO, _SPI0_FUNC);
}
break;
case 1:
_set_pin_function(_SPI1_MISO_GPIO, _SPI1_FUNC);
_set_pin_function(_SPI1_MOSI_GPIO, _SPI1_FUNC);
_set_pin_function(_SPI1_SCK_GPIO, _SPI1_FUNC);
if (!minimal_pins)
_set_pin_function(_SPI1_CS0_GPIO, _SPI1_FUNC);
break;
default:
return false;
}
SPI(bus).USER0 = SPI_USER0_MOSI | SPI_USER0_CLOCK_IN_EDGE | SPI_USER0_DUPLEX |
(minimal_pins ? 0 : (SPI_USER0_CS_HOLD | SPI_USER0_CS_SETUP));
spi_set_frequency_div(bus, freq_divider);
spi_set_mode(bus, mode);
spi_set_msb(bus, msb);
spi_set_endianness(bus, endianness);
return true;
}
void spi_set_mode(uint8_t bus, spi_mode_t mode)
{
bool cpha = (uint8_t)mode & 1;
bool cpol = (uint8_t)mode & 2;
if (cpol)
cpha = !cpha; // CPHA must be inverted when CPOL = 1, I have no idea why
// CPHA
if (cpha)
SPI(bus).USER0 |= SPI_USER0_CLOCK_OUT_EDGE;
else
SPI(bus).USER0 &= ~SPI_USER0_CLOCK_OUT_EDGE;
// CPOL - see http://bbs.espressif.com/viewtopic.php?t=342#p5384
if (cpol)
SPI(bus).PIN |= SPI_PIN_IDLE_EDGE;
else
SPI(bus).PIN &= ~SPI_PIN_IDLE_EDGE;
}
spi_mode_t spi_get_mode(uint8_t bus)
{
uint8_t cpha = SPI(bus).USER0 & SPI_USER0_CLOCK_OUT_EDGE ? 1 : 0;
uint8_t cpol = SPI(bus).PIN & SPI_PIN_IDLE_EDGE ? 2 : 0;
return (spi_mode_t)(cpol | (cpol ? 1 - cpha : cpha)); // see spi_set_mode
}
void spi_set_msb(uint8_t bus, bool msb)
{
if (msb)
SPI(bus).CTRL0 &= ~(SPI_CTRL0_WR_BIT_ORDER | SPI_CTRL0_RD_BIT_ORDER);
else
SPI(bus).CTRL0 |= (SPI_CTRL0_WR_BIT_ORDER | SPI_CTRL0_RD_BIT_ORDER);
}
void spi_set_endianness(uint8_t bus, spi_endianness_t endianness)
{
if (endianness == SPI_BIG_ENDIAN)
SPI(bus).USER0 |= (SPI_USER0_WR_BYTE_ORDER | SPI_USER0_RD_BYTE_ORDER);
else
SPI(bus).USER0 &= ~(SPI_USER0_WR_BYTE_ORDER | SPI_USER0_RD_BYTE_ORDER);
}
void spi_set_frequency_div(uint8_t bus, uint32_t divider)
{
uint32_t predivider = (divider & 0xffff) - 1;
uint32_t count = (divider >> 16) - 1;
if (count || predivider)
{
IOMUX.CONF &= ~(bus == 0 ? IOMUX_CONF_SPI0_CLOCK_EQU_SYS_CLOCK : IOMUX_CONF_SPI1_CLOCK_EQU_SYS_CLOCK);
SPI(bus).CLOCK = VAL2FIELD_M(SPI_CLOCK_DIV_PRE, predivider) |
VAL2FIELD_M(SPI_CLOCK_COUNT_NUM, count) |
VAL2FIELD_M(SPI_CLOCK_COUNT_HIGH, count / 2) |
VAL2FIELD_M(SPI_CLOCK_COUNT_LOW, count);
}
else
{
IOMUX.CONF |= bus == 0 ? IOMUX_CONF_SPI0_CLOCK_EQU_SYS_CLOCK : IOMUX_CONF_SPI1_CLOCK_EQU_SYS_CLOCK;
SPI(bus).CLOCK = SPI_CLOCK_EQU_SYS_CLOCK;
}
}
inline static void _set_size(uint8_t bus, uint8_t bytes)
{
uint32_t bits = ((uint32_t)bytes << 3) - 1;
SPI(bus).USER1 = SET_FIELD(SPI(bus).USER1, SPI_USER1_MISO_BITLEN, bits);
SPI(bus).USER1 = SET_FIELD(SPI(bus).USER1, SPI_USER1_MOSI_BITLEN, bits);
}
inline static void _wait(uint8_t bus)
{
while (SPI(bus).CMD & SPI_CMD_USR)
;
}
inline static void _start(uint8_t bus)
{
SPI(bus).CMD |= SPI_CMD_USR;
}
inline static uint32_t _swap_bytes(uint32_t value)
{
return (value << 24) | ((value << 8) & 0x00ff0000) | ((value >> 8) & 0x0000ff00) | (value >> 24);
}
inline static uint32_t _swap_words(uint32_t value)
{
return (value << 16) | (value >> 16);
}
static void _prepare_buffer(uint8_t bus, size_t len, spi_endianness_t e, spi_word_size_t word_size)
{
if (e == SPI_LITTLE_ENDIAN || word_size == SPI_32BIT) return;
if (word_size == SPI_16BIT)
{
if (len % 2)
len ++;
len /= 2;
}
uint32_t *data = (uint32_t *)&SPI(bus).W0;
for (size_t i = 0; i < len; i ++)
{
data[i] = word_size == SPI_16BIT
? _swap_words(data[i])
: _swap_bytes(data[i]);
}
}
static void _spi_buf_transfer(uint8_t bus, const void *out_data, void *in_data,
size_t len, spi_endianness_t e, spi_word_size_t word_size)
{
_wait(bus);
size_t bytes = len * (uint8_t)word_size;
_set_size(bus, bytes);
memcpy((void *)&SPI(bus).W0, out_data, bytes);
_prepare_buffer(bus, len, e, word_size);
_start(bus);
_wait(bus);
if (in_data)
{
_prepare_buffer(bus, len, e, word_size);
memcpy(in_data, (void *)&SPI(bus).W0, bytes);
}
}
uint8_t spi_transfer_8(uint8_t bus, uint8_t data)
{
uint8_t res;
_spi_buf_transfer(bus, &data, &res, 1, spi_get_endianness(bus), SPI_8BIT);
return res;
}
uint16_t spi_transfer_16(uint8_t bus, uint16_t data)
{
uint16_t res;
_spi_buf_transfer(bus, &data, &res, 1, spi_get_endianness(bus), SPI_16BIT);
return res;
}
uint32_t spi_transfer_32(uint8_t bus, uint32_t data)
{
uint32_t res;
_spi_buf_transfer(bus, &data, &res, 1, spi_get_endianness(bus), SPI_32BIT);
return res;
}
size_t spi_transfer(uint8_t bus, const void *out_data, void *in_data, size_t len, spi_word_size_t word_size)
{
if (!out_data || !len) return 0;
spi_endianness_t e = spi_get_endianness(bus);
uint8_t buf_size = _SPI_BUF_SIZE / (uint8_t)word_size;
size_t blocks = len / buf_size;
for (size_t i = 0; i < blocks; i++)
{
size_t offset = i * _SPI_BUF_SIZE;
_spi_buf_transfer(bus, (const uint8_t *)out_data + offset,
in_data ? (uint8_t *)in_data + offset : NULL, buf_size, e, word_size);
}
uint8_t tail = len % buf_size;
if (tail)
{
_spi_buf_transfer(bus, (const uint8_t *)out_data + blocks * _SPI_BUF_SIZE,
in_data ? (uint8_t *)in_data + blocks * _SPI_BUF_SIZE : NULL, tail, e, word_size);
}
return len;
}

207
core/include/esp/spi.h Normal file
View file

@ -0,0 +1,207 @@
/**
* \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))
/**
* 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;
/**
* \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 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
* Note the result is 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_ */

2
core/include/esp/spi_regs.h
View file

@ -152,6 +152,7 @@ _Static_assert(sizeof(struct SPI_REGS) == 0x100, "SPI_REGS is the wrong size");
#define SPI_USER0_CS_SETUP BIT(5)
#define SPI_USER0_CS_HOLD BIT(4)
#define SPI_USER0_FLASH_MODE BIT(2)
#define SPI_USER0_DUPLEX BIT(0)
/* Details for USER1 register */
@ -173,6 +174,7 @@ _Static_assert(sizeof(struct SPI_REGS) == 0x100, "SPI_REGS is the wrong size");
/* Details for PIN register */
#define SPI_PIN_IDLE_EDGE BIT(29) ///< CPOL
#define SPI_PIN_CS2_DISABLE BIT(2)
#define SPI_PIN_CS1_DISABLE BIT(1)
#define SPI_PIN_CS0_DISABLE BIT(0)