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mbed-os/targets/TARGET_GigaDevice/TARGET_GD32F30X/spi_api.c

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/* mbed Microcontroller Library
* Copyright (c) 2018 GigaDevice Semiconductor Inc.
*
* SPDX-License-Identifier: Apache-2.0
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "mbed_assert.h"
#include "mbed_error.h"
#include "spi_api.h"
#if DEVICE_SPI
#include "cmsis.h"
#include "pinmap.h"
#include "PeripheralPins.h"
#define SPI_S(obj) (( struct spi_s *)(obj))
/** Get the frequency of SPI clock source
*
* Configures the pins used by SPI, sets a default format and frequency, and enables the peripheral
* @param[out] spi_freq The SPI clock source freguency
* @param[in] obj The SPI object
*/
static int dev_spi_clock_source_frequency_get(spi_t *obj)
{
int spi_freq = 0;
struct spi_s *spiobj = SPI_S(obj);
switch ((int)spiobj->spi) {
case SPI0:
/* clock source is APB2 */
spi_freq = rcu_clock_freq_get(CK_APB2);
break;
case SPI1:
/* clock source is APB1 */
spi_freq = rcu_clock_freq_get(CK_APB1);
break;
case SPI2:
/* clock source is APB1 */
spi_freq = rcu_clock_freq_get(CK_APB1);
break;
default:
error("SPI clock source frequency get error");
break;
}
return spi_freq;
}
/** Initialize the SPI structure
*
* Configures the pins used by SPI, sets a default format and frequency, and enables the peripheral
* @param[out] obj The SPI object to initialize
*/
static void dev_spi_struct_init(spi_t *obj)
{
struct spi_s *spiobj = SPI_S(obj);
spi_disable(spiobj->spi);
spi_para_init(spiobj->spi, &obj->spi_struct);
spi_enable(spiobj->spi);
}
/** Initialize the SPI peripheral
*
* Configures the pins used by SPI, sets a default format and frequency, and enables the peripheral
* @param[out] obj The SPI object to initialize
* @param[in] mosi The pin to use for MOSI
* @param[in] miso The pin to use for MISO
* @param[in] sclk The pin to use for SCLK
* @param[in] ssel The pin to use for SSEL
*/
void spi_init(spi_t *obj, PinName mosi, PinName miso, PinName sclk, PinName ssel)
{
struct spi_s *spiobj = SPI_S(obj);
SPIName spi_mosi = (SPIName)pinmap_peripheral(mosi, PinMap_SPI_MOSI);
SPIName spi_miso = (SPIName)pinmap_peripheral(miso, PinMap_SPI_MISO);
SPIName spi_sclk = (SPIName)pinmap_peripheral(sclk, PinMap_SPI_SCLK);
SPIName spi_ssel = (SPIName)pinmap_peripheral(ssel, PinMap_SPI_SSEL);
/* return SPIName according to PinName */
SPIName spi_data = (SPIName)pinmap_merge(spi_mosi, spi_miso);
SPIName spi_cntl = (SPIName)pinmap_merge(spi_sclk, spi_ssel);
spiobj->spi = (SPIName)pinmap_merge(spi_data, spi_cntl);
MBED_ASSERT(spiobj->spi != (SPIName)NC);
/* Set iqr type */
if (spiobj->spi == SPI0) {
rcu_periph_clock_enable(RCU_SPI0);
spiobj->spi_irq = SPI0_IRQn;
}
if (spiobj->spi == SPI1) {
rcu_periph_clock_enable(RCU_SPI1);
spiobj->spi_irq = SPI1_IRQn;
}
if (spiobj->spi == SPI2) {
rcu_periph_clock_enable(RCU_SPI2);
spiobj->spi_irq = SPI2_IRQn;
}
/* config GPIO mode of SPI pins */
pinmap_pinout(mosi, PinMap_SPI_MOSI);
pinmap_pinout(miso, PinMap_SPI_MISO);
pinmap_pinout(sclk, PinMap_SPI_SCLK);
spiobj->pin_miso = miso;
spiobj->pin_mosi = mosi;
spiobj->pin_sclk = sclk;
spiobj->pin_ssel = ssel;
if (ssel != NC) {
pinmap_pinout(ssel, PinMap_SPI_SSEL);
spiobj->spi_struct.nss = SPI_NSS_HARD;
} else {
spiobj->spi_struct.nss = SPI_NSS_SOFT;
}
/* Default values */
spiobj->spi_struct.device_mode = SPI_MASTER;
spiobj->spi_struct.prescale = SPI_PSC_256;
spiobj->spi_struct.trans_mode = SPI_TRANSMODE_FULLDUPLEX;
spiobj->spi_struct.clock_polarity_phase = SPI_CK_PL_LOW_PH_1EDGE;
spiobj->spi_struct.frame_size = SPI_FRAMESIZE_8BIT;
spiobj->spi_struct.endian = SPI_ENDIAN_MSB;
dev_spi_struct_init(obj);
}
/** Release a SPI object
*
* TODO: spi_free is currently unimplemented
* This will require reference counting at the C++ level to be safe
*
* Return the pins owned by the SPI object to their reset state
* Disable the SPI peripheral
* Disable the SPI clock
* @param[in] obj The SPI object to deinitialize
*/
void spi_free(spi_t *obj)
{
struct spi_s *spiobj = SPI_S(obj);
spi_disable(spiobj->spi);
/* Disable and deinit SPI */
if (spiobj->spi == SPI0) {
spi_i2s_deinit(SPI0);
rcu_periph_clock_disable(RCU_SPI0);
}
if (spiobj->spi == SPI1) {
spi_i2s_deinit(SPI1);
rcu_periph_clock_disable(RCU_SPI1);
}
if (spiobj->spi == SPI2) {
spi_i2s_deinit(SPI2);
rcu_periph_clock_disable(RCU_SPI2);
}
/* Deinit GPIO mode of SPI pins */
pin_function(spiobj->pin_miso, MODE_IN_FLOATING);
pin_function(spiobj->pin_mosi, MODE_IN_FLOATING);
pin_function(spiobj->pin_sclk, MODE_IN_FLOATING);
if (spiobj->spi_struct.nss != SPI_NSS_SOFT) {
pin_function(spiobj->pin_ssel, MODE_IN_FLOATING);
}
}
/** Configure the SPI format
*
* Set the number of bits per frame, configure clock polarity and phase, shift order and master/slave mode.
* The default bit order is MSB.
* @param[in,out] obj The SPI object to configure
* @param[in] bits The number of bits per frame
* @param[in] mode The SPI mode (clock polarity, phase, and shift direction)
* @param[in] slave Zero for master mode or non-zero for slave mode
*/
void spi_format(spi_t *obj, int bits, int mode, int slave)
{
struct spi_s *spiobj = SPI_S(obj);
spiobj->spi_struct.frame_size = (bits == 16) ? SPI_FRAMESIZE_16BIT : SPI_FRAMESIZE_8BIT;
/* Config polarity and phase of SPI */
switch (mode) {
case 0:
spiobj->spi_struct.clock_polarity_phase = SPI_CK_PL_LOW_PH_1EDGE;
break;
case 1:
spiobj->spi_struct.clock_polarity_phase = SPI_CK_PL_LOW_PH_2EDGE;
break;
case 2:
spiobj->spi_struct.clock_polarity_phase = SPI_CK_PL_HIGH_PH_1EDGE;
break;
default:
spiobj->spi_struct.clock_polarity_phase = SPI_CK_PL_HIGH_PH_2EDGE;
break;
}
if (spiobj->spi_struct.nss != SPI_NSS_SOFT) {
spiobj->spi_struct.nss = SPI_NSS_HARD;
spi_nss_output_enable(spiobj->spi);
}
/* Select SPI as master or slave */
spiobj->spi_struct.device_mode = (slave) ? SPI_SLAVE : SPI_MASTER;
dev_spi_struct_init(obj);
}
static const uint16_t baudrate_prescaler_table[] = {SPI_PSC_2,
SPI_PSC_4,
SPI_PSC_8,
SPI_PSC_16,
SPI_PSC_32,
SPI_PSC_64,
SPI_PSC_128,
SPI_PSC_256
};
/** 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)
{
struct spi_s *spiobj = SPI_S(obj);
int spi_hz = 0;
uint8_t prescaler_rank = 0;
uint8_t last_index = (sizeof(baudrate_prescaler_table) / sizeof(baudrate_prescaler_table[0])) - 1;
spi_hz = dev_spi_clock_source_frequency_get(obj) / 2;
/* Config SPI prescaler according to input frequency*/
while ((spi_hz > hz) && (prescaler_rank < last_index)) {
spi_hz = spi_hz / 2;
prescaler_rank++;
}
spiobj->spi_struct.prescale = baudrate_prescaler_table[prescaler_rank];
dev_spi_struct_init(obj);
}
/** Write a block out in master mode and receive a value
*
* The total number of bytes sent and received will be the maximum of
* tx_length and rx_length. The bytes written will be padded with the
* value 0xff.
*
* @param[in] obj The SPI peripheral to use for sending
* @param[in] tx_buffer Pointer to the byte-array of data to write to the device
* @param[in] tx_length Number of bytes to write, may be zero
* @param[in] rx_buffer Pointer to the byte-array of data to read from the device
* @param[in] rx_length Number of bytes to read, may be zero
* @param[in] write_fill Default data transmitted while performing a read
* @returns
* The number of bytes written and read from the device. This is
* maximum of tx_length and rx_length.
*/
int spi_master_block_write(spi_t *obj, const char *tx_buffer, int tx_length, char *rx_buffer, int rx_length, char write_fill)
{
int total = (tx_length > rx_length) ? tx_length : rx_length;
for (int i = 0; i < total; i++) {
char out = (i < tx_length) ? tx_buffer[i] : write_fill;
char in = spi_master_write(obj, out);
if (i < rx_length) {
rx_buffer[i] = in;
}
}
return total;
}
/** Write a byte out in master mode and receive a value
*
* @param[in] obj The SPI peripheral to use for sending
* @param[in] value The value to send
* @return Returns the value received during send
*/
int spi_master_write(spi_t *obj, int value)
{
int count = 0;
struct spi_s *spiobj = SPI_S(obj);
/* wait the SPI transmit buffer is empty */
while ((RESET == spi_i2s_flag_get(spiobj->spi, SPI_FLAG_TBE)) && (count++ < 1000));
if (count >= 1000) {
return -1;
} else {
spi_i2s_data_transmit(spiobj->spi, value);
}
count = 0;
/* wait the SPI receive buffer is not empty */
while ((RESET == spi_i2s_flag_get(spiobj->spi, SPI_FLAG_RBNE)) && (count++ < 1000));
if (count >= 1000) {
return -1;
} else {
return spi_i2s_data_receive(spiobj->spi);
}
}
/** Check if a value is available to read
*
* @param[in] obj The SPI peripheral to check
* @return non-zero if a value is available
*/
int spi_slave_receive(spi_t *obj)
{
int status;
struct spi_s *spiobj = SPI_S(obj);
/* check whether or not the SPI receive buffer is empty */
status = ((spi_i2s_flag_get(spiobj->spi, SPI_FLAG_RBNE) != RESET) ? 1 : 0);
return status;
}
/** Get a received value out of the SPI receive buffer in slave mode
*
* Blocks until a value is available
* @param[in] obj The SPI peripheral to read
* @return The value received
*/
int spi_slave_read(spi_t *obj)
{
int count = 0;
struct spi_s *spiobj = SPI_S(obj);
/* wait the SPI receive buffer is not empty */
while ((RESET == spi_i2s_flag_get(spiobj->spi, SPI_FLAG_RBNE)) && (count++ < 1000));
if (count >= 1000) {
return -1;
} else {
return spi_i2s_data_receive(spiobj->spi);
}
}
/** Write a value to the SPI peripheral in slave mode
*
* Blocks until the SPI peripheral can be written to
* @param[in] obj The SPI peripheral to write
* @param[in] value The value to write
*/
void spi_slave_write(spi_t *obj, int value)
{
struct spi_s *spiobj = SPI_S(obj);
/* wait the SPI transmit buffer is empty */
while (RESET == spi_i2s_flag_get(spiobj->spi, SPI_FLAG_TBE));
spi_i2s_data_transmit(spiobj->spi, value);
}
/** Checks if the specified SPI peripheral is in use
*
* @param[in] obj The SPI peripheral to check
* @return non-zero if the peripheral is currently transmitting
*/
int spi_busy(spi_t *obj)
{
int status;
struct spi_s *spiobj = SPI_S(obj);
/* check whether or not the SPI is busy */
status = ((spi_i2s_flag_get(spiobj->spi, SPI_FLAG_TRANS) != RESET) ? 1 : 0);
return status;
}
const PinMap *spi_master_mosi_pinmap()
{
return PinMap_SPI_MOSI;
}
const PinMap *spi_master_miso_pinmap()
{
return PinMap_SPI_MISO;
}
const PinMap *spi_master_clk_pinmap()
{
return PinMap_SPI_SCLK;
}
const PinMap *spi_master_cs_pinmap()
{
return PinMap_SPI_SSEL;
}
const PinMap *spi_slave_mosi_pinmap()
{
return PinMap_SPI_MOSI;
}
const PinMap *spi_slave_miso_pinmap()
{
return PinMap_SPI_MISO;
}
const PinMap *spi_slave_clk_pinmap()
{
return PinMap_SPI_SCLK;
}
const PinMap *spi_slave_cs_pinmap()
{
return PinMap_SPI_SSEL;
}
#endif
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