/**
* \brief Initialize SPI as master.
*/
static void spi_master_initialize(void)
{
/* Configure an SPI peripheral. */
uint32_t spi_chip_sel, spi_clk_freq, spi_clk_pol, spi_clk_pha;
spi_enable_clock(SPI_MASTER_BASE);
spi_reset(SPI_MASTER_BASE);
spi_set_master_mode(SPI_MASTER_BASE);
spi_disable_mode_fault_detect(SPI_MASTER_BASE);
spi_disable_loopback(SPI_MASTER_BASE);
spi_set_peripheral_chip_select_value(SPI_MASTER_BASE, spi_get_pcs(2)); // This sets the value of PCS within the Mode Register.
spi_set_variable_peripheral_select(SPI_MASTER_BASE); // PCS needs to be set within each transfer (PCS within SPI_TDR).
spi_disable_peripheral_select_decode(SPI_MASTER_BASE); // Each CS is to be connected to a single device.
spi_set_delay_between_chip_select(SPI_MASTER_BASE, SPI_DLYBCS);
/* Set communication parameters for CS0 */
spi_chip_sel = 0;
spi_clk_freq = 100000; // SPI CLK for RTC = 100kHz.
spi_clk_pol = 1;
spi_clk_pha = 0;
spi_set_transfer_delay(SPI_MASTER_BASE, spi_chip_sel, SPI_DLYBS,
SPI_DLYBCT);
spi_set_bits_per_transfer(SPI_MASTER_BASE, spi_chip_sel, SPI_CSR_BITS_16_BIT);
spi_set_baudrate_div(SPI_MASTER_BASE, spi_chip_sel, spi_calc_baudrate_div(spi_clk_freq, sysclk_get_cpu_hz()));
spi_configure_cs_behavior(SPI_MASTER_BASE, spi_chip_sel, SPI_CS_RISE_FORCED); // CS rises after SPI transfers have completed.
spi_set_clock_polarity(SPI_MASTER_BASE, spi_chip_sel, spi_clk_pol);
spi_set_clock_phase(SPI_MASTER_BASE, spi_chip_sel, spi_clk_pha);
/* Set communication parameters for CS1 */
spi_chip_sel = 1;
spi_clk_freq = 2000000; // SPI CLK for RTC = 4MHz.
spi_clk_pol = 0;
spi_clk_pha = 0;
spi_set_transfer_delay(SPI_MASTER_BASE, spi_chip_sel, SPI_DLYBS,
SPI_DLYBCT);
spi_set_bits_per_transfer(SPI_MASTER_BASE, spi_chip_sel, SPI_CSR_BITS_8_BIT);
spi_set_baudrate_div(SPI_MASTER_BASE, spi_chip_sel, spi_calc_baudrate_div(spi_clk_freq, sysclk_get_cpu_hz()));
spi_configure_cs_behavior(SPI_MASTER_BASE, spi_chip_sel, SPI_CS_RISE_FORCED);
spi_set_clock_polarity(SPI_MASTER_BASE, spi_chip_sel, spi_clk_pol);
spi_set_clock_phase(SPI_MASTER_BASE, spi_chip_sel, spi_clk_pha);
/* Set communication parameters for CS2 */
spi_chip_sel = 2;
spi_clk_freq = 44000000; // SPI CLK for MEM2 = 44MHz.
spi_clk_pol = 1;
spi_clk_pha = 0;
spi_set_transfer_delay(SPI_MASTER_BASE, spi_chip_sel, SPI_DLYBS,
SPI_DLYBCT);
spi_set_bits_per_transfer(SPI_MASTER_BASE, spi_chip_sel, SPI_CSR_BITS_8_BIT);
spi_set_baudrate_div(SPI_MASTER_BASE, spi_chip_sel, spi_calc_baudrate_div(spi_clk_freq, sysclk_get_cpu_hz()));
spi_configure_cs_behavior(SPI_MASTER_BASE, spi_chip_sel, SPI_CS_KEEP_LOW);
spi_set_clock_polarity(SPI_MASTER_BASE, spi_chip_sel, spi_clk_pol);
spi_set_clock_phase(SPI_MASTER_BASE, spi_chip_sel, spi_clk_pha);
/* Enable SPI Communication */
spi_enable(SPI_MASTER_BASE);
}
/**
* \brief Set up an SPI device.
*
* The returned device descriptor structure must be passed to the driver
* whenever that device should be used as current slave device.
*
* \param p_spi Base address of the SPI instance.
* \param device Pointer to SPI device struct that should be initialized.
* \param flags SPI configuration flags. Common flags for all
* implementations are the SPI modes SPI_MODE_0 ...
* SPI_MODE_3.
* \param baud_rate Baud rate for communication with slave device in Hz.
* \param sel_id Board specific select id.
*/
void spi_master_setup_device(Spi *p_spi, struct spi_device *device,
spi_flags_t flags, uint32_t baud_rate, board_spi_select_id_t sel_id)
{
sel_id = sel_id;
spi_set_transfer_delay(p_spi, device->id, CONFIG_SPI_MASTER_DELAY_BS,
CONFIG_SPI_MASTER_DELAY_BCT);
spi_set_bits_per_transfer(p_spi, device->id,
CONFIG_SPI_MASTER_BITS_PER_TRANSFER);
spi_set_baudrate_div(p_spi, device->id,
spi_calc_baudrate_div(baud_rate, sysclk_get_cpu_hz()));
spi_configure_cs_behavior(p_spi, device->id, SPI_CS_KEEP_LOW);
spi_set_clock_polarity(p_spi, device->id, flags >> 1);
spi_set_clock_phase(p_spi, device->id, ((flags & 0x1) ^ 0x1));
}
/**
* \brief Set up an SPI device.
*
* The returned device descriptor structure must be passed to the driver
* whenever that device should be used as current slave device.
*
* \param p_spi Base address of the SPI instance.
* \param device Pointer to SPI device struct that should be initialized.
* \param flags SPI configuration flags. Common flags for all
* implementations are the SPI modes SPI_MODE_0 ...
* SPI_MODE_3.
* \param baud_rate Baud rate for communication with slave device in Hz.
* \param sel_id Board specific select id.
*/
void spi_master_setup_device(Spi *p_spi, struct spi_device *device,
spi_flags_t flags, uint32_t baud_rate, board_spi_select_id_t sel_id)
{
int16_t baud_div = spi_calc_baudrate_div(baud_rate, sysclk_get_cpu_hz());
/* avoid Cppcheck Warning */
UNUSED(sel_id);
if (-1 == baud_div) {
Assert(0 == "Failed to find baudrate divider");
}
spi_set_transfer_delay(p_spi, device->id, CONFIG_SPI_MASTER_DELAY_BS,
CONFIG_SPI_MASTER_DELAY_BCT);
spi_set_bits_per_transfer(p_spi, device->id,
CONFIG_SPI_MASTER_BITS_PER_TRANSFER);
spi_set_baudrate_div(p_spi, device->id, baud_div);
spi_configure_cs_behavior(p_spi, device->id, SPI_CS_KEEP_LOW);
spi_set_clock_polarity(p_spi, device->id, flags >> 1);
spi_set_clock_phase(p_spi, device->id, ((flags & 0x1) ^ 0x1));
}
/**
* \brief Set up an SPI device.
*
* The returned device descriptor structure must be passed to the driver
* whenever that device should be used as current slave device.
*
* \param p_spi Base address of the SPI instance.
* \param device Pointer to SPI device struct that should be initialized.
* \param flags SPI configuration flags. Common flags for all
* implementations are the SPI modes SPI_MODE_0 ...
* SPI_MODE_3.
* \param baud_rate Baud rate for communication with slave device in Hz.
* \param sel_id Board specific select id.
*/
void spi_master_setup_device(Spi *p_spi, const struct spi_device *device,
spi_flags_t flags, uint32_t baud_rate, board_spi_select_id_t sel_id)
{
/* avoid Cppcheck Warning */
UNUSED(sel_id);
UNUSED(flags);
spi_reset(p_spi);
spi_set_transfer_delay(p_spi, device->id, CONFIG_SPI_MASTER_DELAY_BS,
CONFIG_SPI_MASTER_DELAY_BCT);
spi_set_bits_per_transfer(p_spi, device->id,
CONFIG_SPI_MASTER_BITS_PER_TRANSFER);
int16_t baud_div = spi_calc_baudrate_div(baud_rate, SystemCoreClock);
spi_set_baudrate_div(p_spi, device->id, baud_div);
spi_configure_cs_behavior(p_spi, device->id, SPI_CS_KEEP_LOW);
spi_set_clock_polarity(p_spi, device->id, flags >> 1);
spi_set_clock_phase(p_spi, device->id, ((flags & 0x1) ^ 0x1));
}
/** Set the SPI baud rate
*
* Actual frequency may differ from the desired frequency due to available dividers and bus clock
* Configures the SPI peripheral's baud rate
* @param[in,out] obj The SPI object to configure
* @param[in] hz The baud rate in Hz
*/
void spi_frequency(spi_t *obj, int hz){
spi_disable(obj->spi.spi_base);
int16_t baudrate_div=spi_calc_baudrate_div(hz, sysclk_get_cpu_hz());
spi_set_baudrate_div(obj->spi.spi_base,obj->spi.cs,(uint8_t)baudrate_div);
spi_enable(obj->spi.spi_base);
}