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spi: Add 16bit wide convenience functions for spi

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Signed-off-by: Michael Ring <mail@michael-ring.org>
Signed-off-by: Brendan Le Foll <brendan.le.foll@intel.com>
This commit is contained in:
Michael Ring
2015-02-17 15:34:01 +00:00
committed by Brendan Le Foll
parent 3a5b992524
commit 55ac2e8996
3 changed files with 117 additions and 0 deletions
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29
api/mraa/spi.h
View File

@@ -104,6 +104,14 @@ mraa_result_t mraa_spi_frequency(mraa_spi_context dev, int hz);
*/
uint8_t mraa_spi_write(mraa_spi_context dev, uint8_t data);
/** Write Two Bytes to the SPI device.
*
* @param dev The Spi context
* @param data Data to send
* @return Data received on the miso line
*/
uint16_t mraa_spi_write_word(mraa_spi_context dev, uint16_t data);
/** Write Buffer of bytes to the SPI device. The pointer return has to be
* free'd by the caller. It will return a NULL pointer in cases of error.
*
@@ -114,6 +122,16 @@ uint8_t mraa_spi_write(mraa_spi_context dev, uint8_t data);
*/
uint8_t* mraa_spi_write_buf(mraa_spi_context dev, uint8_t* data, int length);
/** Write Buffer of uint16 to the SPI device. The pointer return has to be
* free'd by the caller. It will return a NULL pointer in cases of error.
*
* @param dev The Spi context
* @param data to send
* @param length elements (in bytes) within buffer, Max 4096
* @return Data received on the miso line, same length as passed in
*/
uint16_t* mraa_spi_write_buf_word(mraa_spi_context dev, uint16_t* data, int length);
/** Transfer Buffer of bytes to the SPI device. Both send and recv buffers
* are passed in
*
@@ -125,6 +143,17 @@ uint8_t* mraa_spi_write_buf(mraa_spi_context dev, uint8_t* data, int length);
*/
mraa_result_t mraa_spi_transfer_buf(mraa_spi_context dev, uint8_t* data, uint8_t* rxbuf, int length);
/** Transfer Buffer of uint16 to the SPI device. Both send and recv buffers
* are passed in
*
* @param dev The Spi context
* @param data to send
* @param rxbuf buffer to recv data back, may be NULL
* @param length elements (in bytes) within buffer, Max 4096
* @return Result of operation
*/
mraa_result_t mraa_spi_transfer_buf_word(mraa_spi_context dev, uint16_t* data, uint16_t* rxbuf, int length);
/**
* Change the SPI lsb mode
*

36
api/mraa/spi.hpp
View File

@@ -99,6 +99,16 @@ class Spi {
return mraa_spi_write(m_spi, (uint8_t) data);
}
/**
* Write single byte to the SPI device
*
* @param data the byte to send
* @return data received on the miso line
*/
uint16_t write_word(uint16_t data) {
return mraa_spi_write_word(m_spi, (uint16_t) data);
}
/**
* Write buffer of bytes to SPI device The pointer return has to be
* free'd by the caller. It will return a NULL pointer in cases of
@@ -112,6 +122,19 @@ class Spi {
return mraa_spi_write_buf(m_spi, txBuf, length);
}
/**
* Write buffer of bytes to SPI device The pointer return has to be
* free'd by the caller. It will return a NULL pointer in cases of
* error
*
* @param txBuf buffer to send
* @param length size of buffer (in bytes) to send
* @return uint8_t* data received on the miso line. Same length as passed in
*/
uint16_t* write_word(uint16_t* txBuf, int length) {
return mraa_spi_write_buf_word(m_spi, txBuf, length);
}
#ifndef SWIG
/**
* Transfer data to and from SPI device Receive pointer may be null if
@@ -125,6 +148,19 @@ class Spi {
mraa_result_t transfer(uint8_t* txBuf, uint8_t* rxBuf, int length) {
return mraa_spi_transfer_buf(m_spi, txBuf, rxBuf, length);
}
/**
* Transfer data to and from SPI device Receive pointer may be null if
* return data is not needed.
*
* @param data buffer to send
* @param rxBuf buffer to optionally receive data from spi device
* @param length size of buffer to send
* @return Result of operation
*/
mraa_result_t transfer_word(uint16_t* txBuf, uint16_t* rxBuf, int length) {
return mraa_spi_transfer_buf_word(m_spi, txBuf, rxBuf, length);
}
#endif
/**

52
src/spi/spi.c
View File

@@ -256,6 +256,27 @@ mraa_spi_write(mraa_spi_context dev, uint8_t data)
return recv;
}
uint16_t
mraa_spi_write_word(mraa_spi_context dev, uint16_t data) {
struct spi_ioc_transfer msg;
memset(&msg, 0, sizeof(msg));
uint16_t length = 2;
uint16_t recv = 0;
msg.tx_buf = (unsigned long) &data;
msg.rx_buf = (unsigned long) &recv;
msg.speed_hz = dev->clock;
msg.bits_per_word = dev->bpw;
msg.delay_usecs = 0;
msg.len = length;
if (ioctl(dev->devfd, SPI_IOC_MESSAGE(1), &msg) < 0) {
syslog(LOG_ERR, "spi: Failed to perform dev transfer");
return -1;
}
return recv;
}
mraa_result_t
mraa_spi_transfer_buf(mraa_spi_context dev, uint8_t* data, uint8_t* rxbuf, int length)
{
@@ -275,6 +296,24 @@ mraa_spi_transfer_buf(mraa_spi_context dev, uint8_t* data, uint8_t* rxbuf, int l
return MRAA_SUCCESS;
}
mraa_result_t
mraa_spi_transfer_buf_word(mraa_spi_context dev, uint16_t *data, uint16_t *rxbuf, int length) {
struct spi_ioc_transfer msg;
memset(&msg, 0, sizeof(msg));
msg.tx_buf = (unsigned long) data;
msg.rx_buf = (unsigned long) rxbuf;
msg.speed_hz = dev->clock;
msg.bits_per_word = dev->bpw;
msg.delay_usecs = 0;
msg.len = length;
if (ioctl(dev->devfd, SPI_IOC_MESSAGE(1), &msg) < 0) {
syslog(LOG_ERR, "spi: Failed to perform dev transfer");
return MRAA_ERROR_INVALID_RESOURCE;
}
return MRAA_SUCCESS;
}
uint8_t*
mraa_spi_write_buf(mraa_spi_context dev, uint8_t* data, int length)
{
@@ -287,6 +326,19 @@ mraa_spi_write_buf(mraa_spi_context dev, uint8_t* data, int length)
return recv;
}
uint16_t *
mraa_spi_write_buf_word(mraa_spi_context dev, uint16_t *data, int length) {
uint16_t* recv = malloc(sizeof(uint16_t) * length);
if (mraa_spi_transfer_buf_word(dev, data, recv, length) != MRAA_SUCCESS) {
free(recv);
return NULL;
}
return recv;
}
mraa_result_t
mraa_spi_stop(mraa_spi_context dev)
{