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Merge pull request #117 from UncleRus/core/spi_bugfix

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SPI big endian swap bug fix, spi_get_settings()/spi_set_settings()
This commit is contained in:
Alex Stewart 2016-03-18 15:19:56 -07:00
commit cf3f811af1
2 changed files with 86 additions and 15 deletions
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28
core/esp_spi.c
View file

@ -28,6 +28,8 @@
#define _SPI_BUF_SIZE 64
static bool _minimal_pins[2] = {false, false};
inline static void _set_pin_function(uint8_t pin, uint32_t function)
{
iomux_set_function(gpio_to_iomux(pin), function);
@ -59,6 +61,7 @@ bool spi_init(uint8_t bus, spi_mode_t mode, uint32_t freq_divider, bool msb, spi
return false;
}
_minimal_pins[bus] = minimal_pins;
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));
@ -70,6 +73,15 @@ bool spi_init(uint8_t bus, spi_mode_t mode, uint32_t freq_divider, bool msb, spi
return true;
}
void spi_get_settings(uint8_t bus, spi_settings_t *s)
{
s->mode = spi_get_mode(bus);
s->freq_divider = spi_get_frequency_div(bus);
s->msb = spi_get_msb(bus);
s->endianness = spi_get_endianness(bus);
s->minimal_pins = _minimal_pins[bus];
}
void spi_set_mode(uint8_t bus, spi_mode_t mode)
{
bool cpha = (uint8_t)mode & 1;
@ -161,19 +173,13 @@ 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)
static void _spi_buf_prepare(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;
}
size_t count = word_size == SPI_16BIT ? (len + 1) / 2 : (len + 3) / 4;
uint32_t *data = (uint32_t *)&SPI(bus).W0;
for (size_t i = 0; i < len; i ++)
for (size_t i = 0; i < count; i ++)
{
data[i] = word_size == SPI_16BIT
? _swap_words(data[i])
@ -188,12 +194,12 @@ static void _spi_buf_transfer(uint8_t bus, const void *out_data, void *in_data,
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);
_spi_buf_prepare(bus, len, e, word_size);
_start(bus);
_wait(bus);
if (in_data)
{
_prepare_buffer(bus, len, e, word_size);
_spi_buf_prepare(bus, len, e, word_size);
memcpy(in_data, (void *)&SPI(bus).W0, bytes);
}
}

73
core/include/esp/spi.h
View file

@ -19,7 +19,7 @@
* 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))
#define SPI_GET_FREQ_DIV(divider, count) (((count) << 16) | ((divider) & 0xffff))
/**
* Predefinded SPI frequency dividers
@ -59,6 +59,18 @@ typedef enum _spi_word_size_t {
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:
@ -84,11 +96,47 @@ typedef enum _spi_word_size_t {
* \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.
* \param mode Bus mode
*/
void spi_set_mode(uint8_t bus, spi_mode_t mode);
/**
@ -115,8 +163,24 @@ spi_mode_t spi_get_mode(uint8_t bus);
*/
void spi_set_frequency_div(uint8_t bus, uint32_t divider);
/**
* \brief Get SPI bus frequency
* Note the result is in Hz.
* \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
*/
@ -186,6 +250,7 @@ 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);