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stevstrongstevstrong
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SPI clean up + add 16 bit access functions in 8 bit mode
1 parent 359db54 commit 0db43ae

2 files changed

Lines changed: 46 additions & 66 deletions

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‎STM32F1/libraries/SPI/src/SPI.cpp‎

Lines changed: 27 additions & 41 deletions
Original file line numberDiff line numberDiff line change
@@ -31,7 +31,6 @@
3131

3232
#include "SPI.h"
3333

34-
//#define SPI_DEBUG
3534

3635
#include <libmaple/timer.h>
3736
#include <libmaple/util.h>
@@ -92,11 +91,10 @@ static const spi_pins board_spi_pins[] __FLASH__ = {
9291
* Constructor
9392
*/
9493

95-
SPIClass::SPIClass(uint32 spi_num) {
96-
94+
SPIClass::SPIClass(uint32 spi_num)
95+
{
9796
_currentSetting=&_settings[spi_num-1];// SPI channels are called 1 2 and 3 but the array is zero indexed
9897

99-
10098
switch (spi_num) {
10199
#if BOARD_NR_SPI >= 1
102100
case 1:
@@ -119,7 +117,7 @@ SPIClass::SPIClass(uint32 spi_num) {
119117
default:
120118
ASSERT(0);
121119
}
122-
120+
123121
// Init things specific to each SPI device
124122
// clock divider setup is a bit of hack, and needs to be improved at a later date.
125123
_settings[0].spi_d = SPI1;
@@ -149,9 +147,6 @@ SPIClass::SPIClass(uint32 spi_num) {
149147
*/
150148
void SPIClass::updateSettings(void) {
151149
uint32 flags = ((_currentSetting->bitOrder == MSBFIRST ? SPI_FRAME_MSB : SPI_FRAME_LSB) | _currentSetting->dataSize | SPI_SW_SLAVE | SPI_SOFT_SS);
152-
#ifdef SPI_DEBUG
153-
Serial.print("spi_master_enable("); Serial.print(_currentSetting->clockDivider); Serial.print(","); Serial.print(_currentSetting->dataMode); Serial.print(","); Serial.print(flags); Serial.println(")");
154-
#endif
155150
spi_master_enable(_currentSetting->spi_d, (spi_baud_rate)_currentSetting->clockDivider, (spi_mode)_currentSetting->dataMode, flags);
156151
}
157152

@@ -167,9 +162,6 @@ void SPIClass::beginSlave(void) {
167162
spi_init(_currentSetting->spi_d);
168163
configure_gpios(_currentSetting->spi_d, 0);
169164
uint32 flags = ((_currentSetting->bitOrder == MSBFIRST ? SPI_FRAME_MSB : SPI_FRAME_LSB) | _currentSetting->dataSize | SPI_RX_ONLY);
170-
#ifdef SPI_DEBUG
171-
Serial.print("spi_slave_enable("); Serial.print(_currentSetting->dataMode); Serial.print(","); Serial.print(flags); Serial.println(")");
172-
#endif
173165
spi_slave_enable(_currentSetting->spi_d, (spi_mode)_currentSetting->dataMode, flags);
174166
// added for DMA callbacks.
175167
_currentSetting->state = SPI_STATE_READY;
@@ -199,19 +191,13 @@ void SPIClass::end(void) {
199191
/* Roger Clark added 3 functions */
200192
void SPIClass::setClockDivider(uint32_t clockDivider)
201193
{
202-
#ifdef SPI_DEBUG
203-
Serial.print("Clock divider set to "); Serial.println(clockDivider);
204-
#endif
205194
_currentSetting->clockDivider = clockDivider;
206195
uint32 cr1 = _currentSetting->spi_d->regs->CR1 & ~(SPI_CR1_BR);
207196
_currentSetting->spi_d->regs->CR1 = cr1 | (clockDivider & SPI_CR1_BR);
208197
}
209198

210199
void SPIClass::setBitOrder(BitOrder bitOrder)
211200
{
212-
#ifdef SPI_DEBUG
213-
Serial.print("Bit order set to "); Serial.println(bitOrder);
214-
#endif
215201
_currentSetting->bitOrder = bitOrder;
216202
uint32 cr1 = _currentSetting->spi_d->regs->CR1 & ~(SPI_CR1_LSBFIRST);
217203
if ( bitOrder==LSBFIRST ) cr1 |= SPI_CR1_LSBFIRST;
@@ -258,19 +244,13 @@ bit 0 - CPHA : Clock phase
258244
259245
If someone finds this is not the case or sees a logic error with this let me know ;-)
260246
*/
261-
#ifdef SPI_DEBUG
262-
Serial.print("Data mode set to "); Serial.println(dataMode);
263-
#endif
264247
_currentSetting->dataMode = dataMode;
265248
uint32 cr1 = _currentSetting->spi_d->regs->CR1 & ~(SPI_CR1_CPOL|SPI_CR1_CPHA);
266249
_currentSetting->spi_d->regs->CR1 = cr1 | (dataMode & (SPI_CR1_CPOL|SPI_CR1_CPHA));
267250
}
268251

269252
void SPIClass::beginTransaction(uint8_t pin, SPISettings settings)
270253
{
271-
#ifdef SPI_DEBUG
272-
Serial.println("SPIClass::beginTransaction");
273-
#endif
274254
setBitOrder(settings.bitOrder);
275255
setDataMode(settings.dataMode);
276256
setDataSize(settings.dataSize);
@@ -280,9 +260,6 @@ void SPIClass::beginTransaction(uint8_t pin, SPISettings settings)
280260

281261
void SPIClass::beginTransactionSlave(SPISettings settings)
282262
{
283-
#ifdef SPI_DEBUG
284-
Serial.println(F("SPIClass::beginTransactionSlave"));
285-
#endif
286263
setBitOrder(settings.bitOrder);
287264
setDataMode(settings.dataMode);
288265
setDataSize(settings.dataSize);
@@ -291,9 +268,6 @@ void SPIClass::beginTransactionSlave(SPISettings settings)
291268

292269
void SPIClass::endTransaction(void)
293270
{
294-
#ifdef SPI_DEBUG
295-
Serial.println("SPIClass::endTransaction");
296-
#endif
297271
//digitalWrite(_SSPin,HIGH);
298272
#if false
299273
// code from SAM core
@@ -355,6 +329,16 @@ void SPIClass::write(uint16 data)
355329
while (spi_is_busy(_currentSetting->spi_d) != 0); // "... and then wait until BSY=0 before disabling the SPI."
356330
}
357331

332+
void SPIClass::write16(uint16 data)
333+
{
334+
// Added by stevestrong: write two consecutive bytes in 8 bit mode (DFF=0)
335+
spi_tx_reg(_currentSetting->spi_d, data>>8); // write high byte
336+
while (spi_is_tx_empty(_currentSetting->spi_d) == 0); // Wait until TXE=1
337+
spi_tx_reg(_currentSetting->spi_d, data); // write low byte
338+
while (spi_is_tx_empty(_currentSetting->spi_d) == 0); // Wait until TXE=1
339+
while (spi_is_busy(_currentSetting->spi_d) != 0); // wait until BSY=0
340+
}
341+
358342
void SPIClass::write(uint16 data, uint32 n)
359343
{
360344
// Added by stevstrong: Repeatedly send same data by the specified number of times
@@ -384,14 +368,21 @@ uint8 SPIClass::transfer(uint8 byte) const
384368
return (uint8)spi_rx_reg(spi_d); // "... and read the last received data."
385369
}
386370

387-
uint16_t SPIClass::transfer16(uint16_t wr_data) const
371+
uint16_t SPIClass::transfer16(uint16_t data) const
388372
{
373+
// Modified by stevestrong: write & read two consecutive bytes in 8 bit mode (DFF=0)
374+
// This is more effective than two distinct byte transfers
389375
spi_dev * spi_d = _currentSetting->spi_d;
390-
spi_rx_reg(spi_d); // read any previous data
391-
spi_tx_reg(spi_d, wr_data); // "2. Write the first data item to be transmitted into the SPI_DR register (this clears the TXE flag)."
392-
while (spi_is_tx_empty(spi_d) == 0); // "5. Wait until TXE=1 ..."
393-
while (spi_is_busy(spi_d) != 0); // "... and then wait until BSY=0 before disabling the SPI."
394-
return (uint16)spi_rx_reg(spi_d); // "... and read the last received data."
376+
spi_rx_reg(spi_d); // read any previous data
377+
spi_tx_reg(spi_d, data>>8); // write high byte
378+
while (spi_is_tx_empty(spi_d) == 0); // wait until TXE=1
379+
while (spi_is_busy(spi_d) != 0); // wait until BSY=0
380+
uint16_t ret = spi_rx_reg(spi_d)<<8; // read and shift high byte
381+
spi_tx_reg(spi_d, data); // write low byte
382+
while (spi_is_tx_empty(spi_d) == 0); // wait until TXE=1
383+
while (spi_is_busy(spi_d) != 0); // wait until BSY=0
384+
ret += spi_rx_reg(spi_d); // read low byte
385+
return ret;
395386
}
396387

397388
/* Roger Clark and Victor Perez, 2015
@@ -523,19 +514,17 @@ uint8 SPIClass::dmaSendAsync(void * transmitBuf, uint16 length, bool minc) {
523514
//delayMicroseconds(10);
524515
if ((millis() - m) > DMA_TIMEOUT) { b = 2; break; }
525516
}
526-
517+
527518
while (spi_is_tx_empty(_currentSetting->spi_d) == 0); // "5. Wait until TXE=1 ..."
528519
while (spi_is_busy(_currentSetting->spi_d) != 0); // "... and then wait until BSY=0 before disabling the SPI."
529520
spi_tx_dma_disable(_currentSetting->spi_d);
530521
dma_disable(_currentSetting->spiDmaDev, _currentSetting->spiTxDmaChannel);
531522
_currentSetting->state = SPI_STATE_READY;
532523
}
533524

534-
535525
if (length == 0) return 0;
536526
uint32 flags = ( (DMA_MINC_MODE*minc) | DMA_FROM_MEM | DMA_TRNS_CMPLT);
537527

538-
539528
dma_init(_currentSetting->spiDmaDev);
540529
// TX
541530
dma_xfer_size dma_bit_size = (_currentSetting->dataSize==DATA_SIZE_16BIT) ? DMA_SIZE_16BITS : DMA_SIZE_8BITS;
@@ -770,9 +759,6 @@ static const spi_baud_rate baud_rates[8] __FLASH__ = {
770759
*/
771760
static spi_baud_rate determine_baud_rate(spi_dev *dev, uint32_t freq) {
772761
uint32_t clock = 0, i;
773-
#ifdef SPI_DEBUG
774-
Serial.print("determine_baud_rate("); Serial.print(freq); Serial.println(")");
775-
#endif
776762
switch (rcc_dev_clk(dev->clk_id))
777763
{
778764
case RCC_APB2: clock = STM32_PCLK2; break; // 72 Mhz

‎STM32F1/libraries/SPI/src/SPI.h‎

Lines changed: 19 additions & 25 deletions
Original file line numberDiff line numberDiff line change
@@ -176,8 +176,6 @@ static void (*_spi3_this);
176176
class SPIClass {
177177
public:
178178

179-
180-
181179
/**
182180
* @param spiPortNumber Number of the SPI port to manage.
183181
*/
@@ -187,8 +185,6 @@ class SPIClass {
187185
* Set up/tear down
188186
*/
189187

190-
191-
192188
/**
193189
* @brief Equivalent to begin(SPI_1_125MHZ, MSBFIRST, 0).
194190
*/
@@ -268,14 +264,15 @@ class SPIClass {
268264
* @brief Transmit one byte/word.
269265
* @param data to transmit.
270266
*/
271-
void write(uint16 data);
272-
267+
void write(uint16 data);
268+
void write16(uint16 data); // write 2 bytes in 8 bit mode (DFF=0)
269+
273270
/**
274271
* @brief Transmit one byte/word a specified number of times.
275272
* @param data to transmit.
276273
*/
277274
void write(uint16 data, uint32 n);
278-
275+
279276
/**
280277
* @brief Transmit multiple bytes/words.
281278
* @param buffer Bytes/words to transmit.
@@ -293,7 +290,7 @@ class SPIClass {
293290
*/
294291
uint8 transfer(uint8 data) const;
295292
uint16_t transfer16(uint16_t data) const;
296-
293+
297294
/**
298295
* @brief Sets up a DMA Transfer for "length" bytes.
299296
* The transfer mode (8 or 16 bit mode) is evaluated from the SPI peripheral setting.
@@ -321,7 +318,7 @@ class SPIClass {
321318
uint8 dmaSend(void * transmitBuf, uint16 length, bool minc = 1);
322319
void dmaSendSet(void * transmitBuf, bool minc);
323320
uint8 dmaSendRepeat(uint16 length);
324-
321+
325322
uint8 dmaSendAsync(void * transmitBuf, uint16 length, bool minc = 1);
326323
/*
327324
* Pin accessors
@@ -354,24 +351,21 @@ class SPIClass {
354351
* this HardwareSPI instance.
355352
*/
356353
spi_dev* c_dev(void) { return _currentSetting->spi_d; }
357-
358-
354+
359355
spi_dev *dev(){ return _currentSetting->spi_d;}
360-
361-
/**
362-
* @brief Sets the number of the SPI peripheral to be used by
363-
* this HardwareSPI instance.
364-
*
365-
* @param spi_num Number of the SPI port. 1-2 in low density devices
366-
* or 1-3 in high density devices.
367-
*/
368-
356+
357+
/**
358+
* @brief Sets the number of the SPI peripheral to be used by
359+
* this HardwareSPI instance.
360+
*
361+
* @param spi_num Number of the SPI port. 1-2 in low density devices
362+
* or 1-3 in high density devices.
363+
*/
369364
void setModule(int spi_num)
370365
{
371366
_currentSetting=&_settings[spi_num-1];// SPI channels are called 1 2 and 3 but the array is zero indexed
372367
}
373368

374-
375369
/* -- The following methods are deprecated --------------------------- */
376370

377371
/**
@@ -403,20 +397,20 @@ class SPIClass {
403397
* @see HardwareSPI::read()
404398
*/
405399
uint8 recv(void);
406-
400+
407401
private:
408402

409403
SPISettings _settings[BOARD_NR_SPI];
410404
SPISettings *_currentSetting;
411-
405+
412406
void updateSettings(void);
413407
/*
414408
* Functions added for DMA transfers with Callback.
415409
* Experimental.
416410
*/
417-
411+
418412
void EventCallback(void);
419-
413+
420414
static void _spi1EventCallback(void);
421415
static void _spi2EventCallback(void);
422416
#if BOARD_NR_SPI >= 3

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