mbed official / mbed-dev

mbed library sources. Supersedes mbed-src.

Dependents:   Nucleo_Hello_Encoder BLE_iBeaconScan AM1805_DEMO DISCO-F429ZI_ExportTemplate1 ... more

targets/TARGET_GigaDevice/TARGET_GD32E10X/spi_api.c@189:f392fc9709a3, 2019-02-20 (annotated)

Committer:
AnnaBridge
Date:
Wed Feb 20 22:31:08 2019 +0000
Revision:
189:f392fc9709a3
mbed library release version 165

Who changed what in which revision?

UserRevisionLine numberNew contents of line
AnnaBridge 189:f392fc9709a3 1 /* mbed Microcontroller Library
AnnaBridge 189:f392fc9709a3 2 * Copyright (c) 2018 GigaDevice Semiconductor Inc.
AnnaBridge 189:f392fc9709a3 3 *
AnnaBridge 189:f392fc9709a3 4 * SPDX-License-Identifier: Apache-2.0
AnnaBridge 189:f392fc9709a3 5 *
AnnaBridge 189:f392fc9709a3 6 * Licensed under the Apache License, Version 2.0 (the "License");
AnnaBridge 189:f392fc9709a3 7 * you may not use this file except in compliance with the License.
AnnaBridge 189:f392fc9709a3 8 * You may obtain a copy of the License at
AnnaBridge 189:f392fc9709a3 9 *
AnnaBridge 189:f392fc9709a3 10 * http://www.apache.org/licenses/LICENSE-2.0
AnnaBridge 189:f392fc9709a3 11 *
AnnaBridge 189:f392fc9709a3 12 * Unless required by applicable law or agreed to in writing, software
AnnaBridge 189:f392fc9709a3 13 * distributed under the License is distributed on an "AS IS" BASIS,
AnnaBridge 189:f392fc9709a3 14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
AnnaBridge 189:f392fc9709a3 15 * See the License for the specific language governing permissions and
AnnaBridge 189:f392fc9709a3 16 * limitations under the License.
AnnaBridge 189:f392fc9709a3 17 */
AnnaBridge 189:f392fc9709a3 18 #include "mbed_assert.h"
AnnaBridge 189:f392fc9709a3 19 #include "mbed_error.h"
AnnaBridge 189:f392fc9709a3 20 #include "spi_api.h"
AnnaBridge 189:f392fc9709a3 21
AnnaBridge 189:f392fc9709a3 22 #if DEVICE_SPI
AnnaBridge 189:f392fc9709a3 23 #include "cmsis.h"
AnnaBridge 189:f392fc9709a3 24 #include "pinmap.h"
AnnaBridge 189:f392fc9709a3 25 #include "PeripheralPins.h"
AnnaBridge 189:f392fc9709a3 26
AnnaBridge 189:f392fc9709a3 27 #define SPI_S(obj) (( struct spi_s *)(obj))
AnnaBridge 189:f392fc9709a3 28
AnnaBridge 189:f392fc9709a3 29 /** Get the frequency of SPI clock source
AnnaBridge 189:f392fc9709a3 30 *
AnnaBridge 189:f392fc9709a3 31 * Configures the pins used by SPI, sets a default format and frequency, and enables the peripheral
AnnaBridge 189:f392fc9709a3 32 * @param[out] spi_freq The SPI clock source freguency
AnnaBridge 189:f392fc9709a3 33 * @param[in] obj The SPI object
AnnaBridge 189:f392fc9709a3 34 */
AnnaBridge 189:f392fc9709a3 35 static int dev_spi_clock_source_frequency_get(spi_t *obj)
AnnaBridge 189:f392fc9709a3 36 {
AnnaBridge 189:f392fc9709a3 37 int spi_freq = 0;
AnnaBridge 189:f392fc9709a3 38 struct spi_s *spiobj = SPI_S(obj);
AnnaBridge 189:f392fc9709a3 39
AnnaBridge 189:f392fc9709a3 40 switch ((int)spiobj->spi) {
AnnaBridge 189:f392fc9709a3 41 case SPI0:
AnnaBridge 189:f392fc9709a3 42 /* clock source is APB2 */
AnnaBridge 189:f392fc9709a3 43 spi_freq = rcu_clock_freq_get(CK_APB2);
AnnaBridge 189:f392fc9709a3 44 break;
AnnaBridge 189:f392fc9709a3 45 case SPI1:
AnnaBridge 189:f392fc9709a3 46 /* clock source is APB1 */
AnnaBridge 189:f392fc9709a3 47 spi_freq = rcu_clock_freq_get(CK_APB1);
AnnaBridge 189:f392fc9709a3 48 break;
AnnaBridge 189:f392fc9709a3 49 case SPI2:
AnnaBridge 189:f392fc9709a3 50 /* clock source is APB1 */
AnnaBridge 189:f392fc9709a3 51 spi_freq = rcu_clock_freq_get(CK_APB1);
AnnaBridge 189:f392fc9709a3 52 break;
AnnaBridge 189:f392fc9709a3 53 default:
AnnaBridge 189:f392fc9709a3 54 error("SPI clock source frequency get error");
AnnaBridge 189:f392fc9709a3 55 break;
AnnaBridge 189:f392fc9709a3 56 }
AnnaBridge 189:f392fc9709a3 57 return spi_freq;
AnnaBridge 189:f392fc9709a3 58 }
AnnaBridge 189:f392fc9709a3 59
AnnaBridge 189:f392fc9709a3 60 /** Initialize the SPI structure
AnnaBridge 189:f392fc9709a3 61 *
AnnaBridge 189:f392fc9709a3 62 * Configures the pins used by SPI, sets a default format and frequency, and enables the peripheral
AnnaBridge 189:f392fc9709a3 63 * @param[out] obj The SPI object to initialize
AnnaBridge 189:f392fc9709a3 64 */
AnnaBridge 189:f392fc9709a3 65 static void dev_spi_struct_init(spi_t *obj)
AnnaBridge 189:f392fc9709a3 66 {
AnnaBridge 189:f392fc9709a3 67 struct spi_s *spiobj = SPI_S(obj);
AnnaBridge 189:f392fc9709a3 68
AnnaBridge 189:f392fc9709a3 69 spi_disable(spiobj->spi);
AnnaBridge 189:f392fc9709a3 70 spi_para_init(spiobj->spi, &obj->spi_struct);
AnnaBridge 189:f392fc9709a3 71 spi_enable(spiobj->spi);
AnnaBridge 189:f392fc9709a3 72 }
AnnaBridge 189:f392fc9709a3 73
AnnaBridge 189:f392fc9709a3 74 /** Initialize the SPI peripheral
AnnaBridge 189:f392fc9709a3 75 *
AnnaBridge 189:f392fc9709a3 76 * Configures the pins used by SPI, sets a default format and frequency, and enables the peripheral
AnnaBridge 189:f392fc9709a3 77 * @param[out] obj The SPI object to initialize
AnnaBridge 189:f392fc9709a3 78 * @param[in] mosi The pin to use for MOSI
AnnaBridge 189:f392fc9709a3 79 * @param[in] miso The pin to use for MISO
AnnaBridge 189:f392fc9709a3 80 * @param[in] sclk The pin to use for SCLK
AnnaBridge 189:f392fc9709a3 81 * @param[in] ssel The pin to use for SSEL
AnnaBridge 189:f392fc9709a3 82 */
AnnaBridge 189:f392fc9709a3 83 void spi_init(spi_t *obj, PinName mosi, PinName miso, PinName sclk, PinName ssel)
AnnaBridge 189:f392fc9709a3 84 {
AnnaBridge 189:f392fc9709a3 85 struct spi_s *spiobj = SPI_S(obj);
AnnaBridge 189:f392fc9709a3 86
AnnaBridge 189:f392fc9709a3 87 SPIName spi_mosi = (SPIName)pinmap_peripheral(mosi, PinMap_SPI_MOSI);
AnnaBridge 189:f392fc9709a3 88 SPIName spi_miso = (SPIName)pinmap_peripheral(miso, PinMap_SPI_MISO);
AnnaBridge 189:f392fc9709a3 89 SPIName spi_sclk = (SPIName)pinmap_peripheral(sclk, PinMap_SPI_SCLK);
AnnaBridge 189:f392fc9709a3 90 SPIName spi_ssel = (SPIName)pinmap_peripheral(ssel, PinMap_SPI_SSEL);
AnnaBridge 189:f392fc9709a3 91
AnnaBridge 189:f392fc9709a3 92 /* return SPIName according to PinName */
AnnaBridge 189:f392fc9709a3 93 SPIName spi_data = (SPIName)pinmap_merge(spi_mosi, spi_miso);
AnnaBridge 189:f392fc9709a3 94 SPIName spi_cntl = (SPIName)pinmap_merge(spi_sclk, spi_ssel);
AnnaBridge 189:f392fc9709a3 95
AnnaBridge 189:f392fc9709a3 96 spiobj->spi = (SPIName)pinmap_merge(spi_data, spi_cntl);
AnnaBridge 189:f392fc9709a3 97 MBED_ASSERT(spiobj->spi != (SPIName)NC);
AnnaBridge 189:f392fc9709a3 98
AnnaBridge 189:f392fc9709a3 99 /* Set iqr type */
AnnaBridge 189:f392fc9709a3 100 if (spiobj->spi == SPI0) {
AnnaBridge 189:f392fc9709a3 101 rcu_periph_clock_enable(RCU_SPI0);
AnnaBridge 189:f392fc9709a3 102 spiobj->spi_irq = SPI0_IRQn;
AnnaBridge 189:f392fc9709a3 103 }
AnnaBridge 189:f392fc9709a3 104 if (spiobj->spi == SPI1) {
AnnaBridge 189:f392fc9709a3 105 rcu_periph_clock_enable(RCU_SPI1);
AnnaBridge 189:f392fc9709a3 106 spiobj->spi_irq = SPI1_IRQn;
AnnaBridge 189:f392fc9709a3 107 }
AnnaBridge 189:f392fc9709a3 108 if (spiobj->spi == SPI2) {
AnnaBridge 189:f392fc9709a3 109 rcu_periph_clock_enable(RCU_SPI2);
AnnaBridge 189:f392fc9709a3 110 spiobj->spi_irq = SPI2_IRQn;
AnnaBridge 189:f392fc9709a3 111 }
AnnaBridge 189:f392fc9709a3 112
AnnaBridge 189:f392fc9709a3 113 /* config GPIO mode of SPI pins */
AnnaBridge 189:f392fc9709a3 114 pinmap_pinout(mosi, PinMap_SPI_MOSI);
AnnaBridge 189:f392fc9709a3 115 pinmap_pinout(miso, PinMap_SPI_MISO);
AnnaBridge 189:f392fc9709a3 116 pinmap_pinout(sclk, PinMap_SPI_SCLK);
AnnaBridge 189:f392fc9709a3 117 spiobj->pin_miso = miso;
AnnaBridge 189:f392fc9709a3 118 spiobj->pin_mosi = mosi;
AnnaBridge 189:f392fc9709a3 119 spiobj->pin_sclk = sclk;
AnnaBridge 189:f392fc9709a3 120 spiobj->pin_ssel = ssel;
AnnaBridge 189:f392fc9709a3 121 if (ssel != NC) {
AnnaBridge 189:f392fc9709a3 122 pinmap_pinout(ssel, PinMap_SPI_SSEL);
AnnaBridge 189:f392fc9709a3 123 spiobj->spi_struct.nss = SPI_NSS_HARD;
AnnaBridge 189:f392fc9709a3 124 spi_nss_output_enable(spiobj->spi);
AnnaBridge 189:f392fc9709a3 125 } else {
AnnaBridge 189:f392fc9709a3 126 spiobj->spi_struct.nss = SPI_NSS_SOFT;
AnnaBridge 189:f392fc9709a3 127 }
AnnaBridge 189:f392fc9709a3 128
AnnaBridge 189:f392fc9709a3 129 spiobj->spi_struct.device_mode = SPI_MASTER;
AnnaBridge 189:f392fc9709a3 130 spiobj->spi_struct.prescale = SPI_PSC_256;
AnnaBridge 189:f392fc9709a3 131 spiobj->spi_struct.trans_mode = SPI_TRANSMODE_FULLDUPLEX;
AnnaBridge 189:f392fc9709a3 132 spiobj->spi_struct.clock_polarity_phase = SPI_CK_PL_LOW_PH_1EDGE;
AnnaBridge 189:f392fc9709a3 133 spiobj->spi_struct.frame_size = SPI_FRAMESIZE_8BIT;
AnnaBridge 189:f392fc9709a3 134 spiobj->spi_struct.endian = SPI_ENDIAN_MSB;
AnnaBridge 189:f392fc9709a3 135
AnnaBridge 189:f392fc9709a3 136 dev_spi_struct_init(obj);
AnnaBridge 189:f392fc9709a3 137 }
AnnaBridge 189:f392fc9709a3 138
AnnaBridge 189:f392fc9709a3 139 /** Release a SPI object
AnnaBridge 189:f392fc9709a3 140 *
AnnaBridge 189:f392fc9709a3 141 * TODO: spi_free is currently unimplemented
AnnaBridge 189:f392fc9709a3 142 * This will require reference counting at the C++ level to be safe
AnnaBridge 189:f392fc9709a3 143 *
AnnaBridge 189:f392fc9709a3 144 * Return the pins owned by the SPI object to their reset state
AnnaBridge 189:f392fc9709a3 145 * Disable the SPI peripheral
AnnaBridge 189:f392fc9709a3 146 * Disable the SPI clock
AnnaBridge 189:f392fc9709a3 147 * @param[in] obj The SPI object to deinitialize
AnnaBridge 189:f392fc9709a3 148 */
AnnaBridge 189:f392fc9709a3 149 void spi_free(spi_t *obj)
AnnaBridge 189:f392fc9709a3 150 {
AnnaBridge 189:f392fc9709a3 151 struct spi_s *spiobj = SPI_S(obj);
AnnaBridge 189:f392fc9709a3 152 spi_disable(spiobj->spi);
AnnaBridge 189:f392fc9709a3 153
AnnaBridge 189:f392fc9709a3 154 /* Disable and deinit SPI */
AnnaBridge 189:f392fc9709a3 155 if (spiobj->spi == SPI0) {
AnnaBridge 189:f392fc9709a3 156 spi_i2s_deinit(SPI0);
AnnaBridge 189:f392fc9709a3 157 rcu_periph_clock_disable(RCU_SPI0);
AnnaBridge 189:f392fc9709a3 158 }
AnnaBridge 189:f392fc9709a3 159 if (spiobj->spi == SPI1) {
AnnaBridge 189:f392fc9709a3 160 spi_i2s_deinit(SPI1);
AnnaBridge 189:f392fc9709a3 161 rcu_periph_clock_disable(RCU_SPI1);
AnnaBridge 189:f392fc9709a3 162 }
AnnaBridge 189:f392fc9709a3 163 if (spiobj->spi == SPI2) {
AnnaBridge 189:f392fc9709a3 164 spi_i2s_deinit(SPI2);
AnnaBridge 189:f392fc9709a3 165 rcu_periph_clock_disable(RCU_SPI2);
AnnaBridge 189:f392fc9709a3 166 }
AnnaBridge 189:f392fc9709a3 167 /* Deinit GPIO mode of SPI pins */
AnnaBridge 189:f392fc9709a3 168 pin_function(spiobj->pin_miso, MODE_IN_FLOATING);
AnnaBridge 189:f392fc9709a3 169 pin_function(spiobj->pin_mosi, MODE_IN_FLOATING);
AnnaBridge 189:f392fc9709a3 170 pin_function(spiobj->pin_sclk, MODE_IN_FLOATING);
AnnaBridge 189:f392fc9709a3 171 if (spiobj->spi_struct.nss != SPI_NSS_SOFT) {
AnnaBridge 189:f392fc9709a3 172 pin_function(spiobj->pin_ssel, MODE_IN_FLOATING);
AnnaBridge 189:f392fc9709a3 173 }
AnnaBridge 189:f392fc9709a3 174 }
AnnaBridge 189:f392fc9709a3 175
AnnaBridge 189:f392fc9709a3 176 /** Configure the SPI format
AnnaBridge 189:f392fc9709a3 177 *
AnnaBridge 189:f392fc9709a3 178 * Set the number of bits per frame, configure clock polarity and phase, shift order and master/slave mode.
AnnaBridge 189:f392fc9709a3 179 * The default bit order is MSB.
AnnaBridge 189:f392fc9709a3 180 * @param[in,out] obj The SPI object to configure
AnnaBridge 189:f392fc9709a3 181 * @param[in] bits The number of bits per frame
AnnaBridge 189:f392fc9709a3 182 * @param[in] mode The SPI mode (clock polarity, phase, and shift direction)
AnnaBridge 189:f392fc9709a3 183 * @param[in] slave Zero for master mode or non-zero for slave mode
AnnaBridge 189:f392fc9709a3 184 */
AnnaBridge 189:f392fc9709a3 185 void spi_format(spi_t *obj, int bits, int mode, int slave)
AnnaBridge 189:f392fc9709a3 186 {
AnnaBridge 189:f392fc9709a3 187 struct spi_s *spiobj = SPI_S(obj);
AnnaBridge 189:f392fc9709a3 188
AnnaBridge 189:f392fc9709a3 189 spiobj->spi_struct.frame_size = (bits == 16) ? SPI_FRAMESIZE_16BIT : SPI_FRAMESIZE_8BIT;
AnnaBridge 189:f392fc9709a3 190 /* Config polarity and phase of SPI */
AnnaBridge 189:f392fc9709a3 191 switch (mode) {
AnnaBridge 189:f392fc9709a3 192 case 0:
AnnaBridge 189:f392fc9709a3 193 spiobj->spi_struct.clock_polarity_phase = SPI_CK_PL_LOW_PH_1EDGE;
AnnaBridge 189:f392fc9709a3 194 break;
AnnaBridge 189:f392fc9709a3 195 case 1:
AnnaBridge 189:f392fc9709a3 196 spiobj->spi_struct.clock_polarity_phase = SPI_CK_PL_LOW_PH_2EDGE;
AnnaBridge 189:f392fc9709a3 197 break;
AnnaBridge 189:f392fc9709a3 198 case 2:
AnnaBridge 189:f392fc9709a3 199 spiobj->spi_struct.clock_polarity_phase = SPI_CK_PL_HIGH_PH_1EDGE;
AnnaBridge 189:f392fc9709a3 200 break;
AnnaBridge 189:f392fc9709a3 201 default:
AnnaBridge 189:f392fc9709a3 202 spiobj->spi_struct.clock_polarity_phase = SPI_CK_PL_HIGH_PH_2EDGE;
AnnaBridge 189:f392fc9709a3 203
AnnaBridge 189:f392fc9709a3 204 break;
AnnaBridge 189:f392fc9709a3 205 }
AnnaBridge 189:f392fc9709a3 206
AnnaBridge 189:f392fc9709a3 207 if (spiobj->spi_struct.nss != SPI_NSS_SOFT) {
AnnaBridge 189:f392fc9709a3 208 if (slave) {
AnnaBridge 189:f392fc9709a3 209 pin_function(spiobj->pin_mosi, MODE_IN_FLOATING);
AnnaBridge 189:f392fc9709a3 210 pin_function(spiobj->pin_sclk, MODE_IN_FLOATING);
AnnaBridge 189:f392fc9709a3 211 pin_function(spiobj->pin_ssel, MODE_IN_FLOATING);
AnnaBridge 189:f392fc9709a3 212 spi_nss_output_disable(spiobj->spi);
AnnaBridge 189:f392fc9709a3 213 }
AnnaBridge 189:f392fc9709a3 214 }
AnnaBridge 189:f392fc9709a3 215 /* Select SPI as master or slave */
AnnaBridge 189:f392fc9709a3 216 spiobj->spi_struct.device_mode = (slave) ? SPI_SLAVE : SPI_MASTER;
AnnaBridge 189:f392fc9709a3 217
AnnaBridge 189:f392fc9709a3 218 dev_spi_struct_init(obj);
AnnaBridge 189:f392fc9709a3 219 }
AnnaBridge 189:f392fc9709a3 220
AnnaBridge 189:f392fc9709a3 221 static const uint16_t baudrate_prescaler_table[] = {SPI_PSC_2,
AnnaBridge 189:f392fc9709a3 222 SPI_PSC_4,
AnnaBridge 189:f392fc9709a3 223 SPI_PSC_8,
AnnaBridge 189:f392fc9709a3 224 SPI_PSC_16,
AnnaBridge 189:f392fc9709a3 225 SPI_PSC_32,
AnnaBridge 189:f392fc9709a3 226 SPI_PSC_64,
AnnaBridge 189:f392fc9709a3 227 SPI_PSC_128,
AnnaBridge 189:f392fc9709a3 228 SPI_PSC_256
AnnaBridge 189:f392fc9709a3 229 };
AnnaBridge 189:f392fc9709a3 230
AnnaBridge 189:f392fc9709a3 231 /** Set the SPI baud rate
AnnaBridge 189:f392fc9709a3 232 *
AnnaBridge 189:f392fc9709a3 233 * Actual frequency may differ from the desired frequency due to available dividers and bus clock
AnnaBridge 189:f392fc9709a3 234 * Configures the SPI peripheral's baud rate
AnnaBridge 189:f392fc9709a3 235 * @param[in,out] obj The SPI object to configure
AnnaBridge 189:f392fc9709a3 236 * @param[in] hz The baud rate in Hz
AnnaBridge 189:f392fc9709a3 237 */
AnnaBridge 189:f392fc9709a3 238 void spi_frequency(spi_t *obj, int hz)
AnnaBridge 189:f392fc9709a3 239 {
AnnaBridge 189:f392fc9709a3 240 struct spi_s *spiobj = SPI_S(obj);
AnnaBridge 189:f392fc9709a3 241 int spi_hz = 0;
AnnaBridge 189:f392fc9709a3 242 uint8_t prescaler_rank = 0;
AnnaBridge 189:f392fc9709a3 243 uint8_t last_index = (sizeof(baudrate_prescaler_table) / sizeof(baudrate_prescaler_table[0])) - 1;
AnnaBridge 189:f392fc9709a3 244
AnnaBridge 189:f392fc9709a3 245 spi_hz = dev_spi_clock_source_frequency_get(obj) / 2;
AnnaBridge 189:f392fc9709a3 246
AnnaBridge 189:f392fc9709a3 247 /* Config SPI prescaler according to input frequency*/
AnnaBridge 189:f392fc9709a3 248 while ((spi_hz > hz) && (prescaler_rank < last_index)) {
AnnaBridge 189:f392fc9709a3 249 spi_hz = spi_hz / 2;
AnnaBridge 189:f392fc9709a3 250 prescaler_rank++;
AnnaBridge 189:f392fc9709a3 251 }
AnnaBridge 189:f392fc9709a3 252
AnnaBridge 189:f392fc9709a3 253 spiobj->spi_struct.prescale = baudrate_prescaler_table[prescaler_rank];
AnnaBridge 189:f392fc9709a3 254 dev_spi_struct_init(obj);
AnnaBridge 189:f392fc9709a3 255 }
AnnaBridge 189:f392fc9709a3 256
AnnaBridge 189:f392fc9709a3 257 /** Write a block out in master mode and receive a value
AnnaBridge 189:f392fc9709a3 258 *
AnnaBridge 189:f392fc9709a3 259 * The total number of bytes sent and received will be the maximum of
AnnaBridge 189:f392fc9709a3 260 * tx_length and rx_length. The bytes written will be padded with the
AnnaBridge 189:f392fc9709a3 261 * value 0xff.
AnnaBridge 189:f392fc9709a3 262 *
AnnaBridge 189:f392fc9709a3 263 * @param[in] obj The SPI peripheral to use for sending
AnnaBridge 189:f392fc9709a3 264 * @param[in] tx_buffer Pointer to the byte-array of data to write to the device
AnnaBridge 189:f392fc9709a3 265 * @param[in] tx_length Number of bytes to write, may be zero
AnnaBridge 189:f392fc9709a3 266 * @param[in] rx_buffer Pointer to the byte-array of data to read from the device
AnnaBridge 189:f392fc9709a3 267 * @param[in] rx_length Number of bytes to read, may be zero
AnnaBridge 189:f392fc9709a3 268 * @param[in] write_fill Default data transmitted while performing a read
AnnaBridge 189:f392fc9709a3 269 * @returns
AnnaBridge 189:f392fc9709a3 270 * The number of bytes written and read from the device. This is
AnnaBridge 189:f392fc9709a3 271 * maximum of tx_length and rx_length.
AnnaBridge 189:f392fc9709a3 272 */
AnnaBridge 189:f392fc9709a3 273 int spi_master_block_write(spi_t *obj, const char *tx_buffer, int tx_length, char *rx_buffer, int rx_length, char write_fill)
AnnaBridge 189:f392fc9709a3 274 {
AnnaBridge 189:f392fc9709a3 275 int total = (tx_length > rx_length) ? tx_length : rx_length;
AnnaBridge 189:f392fc9709a3 276
AnnaBridge 189:f392fc9709a3 277 for (int i = 0; i < total; i++) {
AnnaBridge 189:f392fc9709a3 278 char out = (i < tx_length) ? tx_buffer[i] : write_fill;
AnnaBridge 189:f392fc9709a3 279 char in = spi_master_write(obj, out);
AnnaBridge 189:f392fc9709a3 280 if (i < rx_length) {
AnnaBridge 189:f392fc9709a3 281 rx_buffer[i] = in;
AnnaBridge 189:f392fc9709a3 282 }
AnnaBridge 189:f392fc9709a3 283 }
AnnaBridge 189:f392fc9709a3 284 return total;
AnnaBridge 189:f392fc9709a3 285 }
AnnaBridge 189:f392fc9709a3 286
AnnaBridge 189:f392fc9709a3 287 /** Write a byte out in master mode and receive a value
AnnaBridge 189:f392fc9709a3 288 *
AnnaBridge 189:f392fc9709a3 289 * @param[in] obj The SPI peripheral to use for sending
AnnaBridge 189:f392fc9709a3 290 * @param[in] value The value to send
AnnaBridge 189:f392fc9709a3 291 * @return Returns the value received during send
AnnaBridge 189:f392fc9709a3 292 */
AnnaBridge 189:f392fc9709a3 293 int spi_master_write(spi_t *obj, int value)
AnnaBridge 189:f392fc9709a3 294 {
AnnaBridge 189:f392fc9709a3 295 int count = 0;
AnnaBridge 189:f392fc9709a3 296 struct spi_s *spiobj = SPI_S(obj);
AnnaBridge 189:f392fc9709a3 297
AnnaBridge 189:f392fc9709a3 298 /* wait the SPI transmit buffer is empty */
AnnaBridge 189:f392fc9709a3 299 while ((RESET == spi_i2s_flag_get(spiobj->spi, SPI_FLAG_TBE)) && (count++ < 1000));
AnnaBridge 189:f392fc9709a3 300 if (count >= 1000) {
AnnaBridge 189:f392fc9709a3 301 return -1;
AnnaBridge 189:f392fc9709a3 302 } else {
AnnaBridge 189:f392fc9709a3 303 spi_i2s_data_transmit(spiobj->spi, value);
AnnaBridge 189:f392fc9709a3 304 }
AnnaBridge 189:f392fc9709a3 305
AnnaBridge 189:f392fc9709a3 306 count = 0;
AnnaBridge 189:f392fc9709a3 307 /* wait the SPI receive buffer is not empty */
AnnaBridge 189:f392fc9709a3 308 while ((RESET == spi_i2s_flag_get(spiobj->spi, SPI_FLAG_RBNE)) && (count++ < 1000));
AnnaBridge 189:f392fc9709a3 309 if (count >= 1000) {
AnnaBridge 189:f392fc9709a3 310 return -1;
AnnaBridge 189:f392fc9709a3 311 } else {
AnnaBridge 189:f392fc9709a3 312 return spi_i2s_data_receive(spiobj->spi);
AnnaBridge 189:f392fc9709a3 313 }
AnnaBridge 189:f392fc9709a3 314
AnnaBridge 189:f392fc9709a3 315 }
AnnaBridge 189:f392fc9709a3 316
AnnaBridge 189:f392fc9709a3 317 /** Check if a value is available to read
AnnaBridge 189:f392fc9709a3 318 *
AnnaBridge 189:f392fc9709a3 319 * @param[in] obj The SPI peripheral to check
AnnaBridge 189:f392fc9709a3 320 * @return non-zero if a value is available
AnnaBridge 189:f392fc9709a3 321 */
AnnaBridge 189:f392fc9709a3 322 int spi_slave_receive(spi_t *obj)
AnnaBridge 189:f392fc9709a3 323 {
AnnaBridge 189:f392fc9709a3 324 int status;
AnnaBridge 189:f392fc9709a3 325 struct spi_s *spiobj = SPI_S(obj);
AnnaBridge 189:f392fc9709a3 326 /* check whether or not the SPI receive buffer is empty */
AnnaBridge 189:f392fc9709a3 327 status = ((spi_i2s_flag_get(spiobj->spi, SPI_FLAG_RBNE) != RESET) ? 1 : 0);
AnnaBridge 189:f392fc9709a3 328 return status;
AnnaBridge 189:f392fc9709a3 329 }
AnnaBridge 189:f392fc9709a3 330
AnnaBridge 189:f392fc9709a3 331 /** Get a received value out of the SPI receive buffer in slave mode
AnnaBridge 189:f392fc9709a3 332 *
AnnaBridge 189:f392fc9709a3 333 * Blocks until a value is available
AnnaBridge 189:f392fc9709a3 334 * @param[in] obj The SPI peripheral to read
AnnaBridge 189:f392fc9709a3 335 * @return The value received
AnnaBridge 189:f392fc9709a3 336 */
AnnaBridge 189:f392fc9709a3 337 int spi_slave_read(spi_t *obj)
AnnaBridge 189:f392fc9709a3 338 {
AnnaBridge 189:f392fc9709a3 339 int count = 0;
AnnaBridge 189:f392fc9709a3 340 struct spi_s *spiobj = SPI_S(obj);
AnnaBridge 189:f392fc9709a3 341 /* wait the SPI receive buffer is not empty */
AnnaBridge 189:f392fc9709a3 342 while ((RESET == spi_i2s_flag_get(spiobj->spi, SPI_FLAG_RBNE)) && (count++ < 1000));
AnnaBridge 189:f392fc9709a3 343 if (count >= 1000) {
AnnaBridge 189:f392fc9709a3 344 return -1;
AnnaBridge 189:f392fc9709a3 345 } else {
AnnaBridge 189:f392fc9709a3 346 return spi_i2s_data_receive(spiobj->spi);
AnnaBridge 189:f392fc9709a3 347 }
AnnaBridge 189:f392fc9709a3 348 }
AnnaBridge 189:f392fc9709a3 349
AnnaBridge 189:f392fc9709a3 350 /** Write a value to the SPI peripheral in slave mode
AnnaBridge 189:f392fc9709a3 351 *
AnnaBridge 189:f392fc9709a3 352 * Blocks until the SPI peripheral can be written to
AnnaBridge 189:f392fc9709a3 353 * @param[in] obj The SPI peripheral to write
AnnaBridge 189:f392fc9709a3 354 * @param[in] value The value to write
AnnaBridge 189:f392fc9709a3 355 */
AnnaBridge 189:f392fc9709a3 356 void spi_slave_write(spi_t *obj, int value)
AnnaBridge 189:f392fc9709a3 357 {
AnnaBridge 189:f392fc9709a3 358 struct spi_s *spiobj = SPI_S(obj);
AnnaBridge 189:f392fc9709a3 359 /* wait the SPI transmit buffer is empty */
AnnaBridge 189:f392fc9709a3 360 while (RESET == spi_i2s_flag_get(spiobj->spi, SPI_FLAG_TBE));
AnnaBridge 189:f392fc9709a3 361 spi_i2s_data_transmit(spiobj->spi, value);
AnnaBridge 189:f392fc9709a3 362 }
AnnaBridge 189:f392fc9709a3 363
AnnaBridge 189:f392fc9709a3 364 /** Checks if the specified SPI peripheral is in use
AnnaBridge 189:f392fc9709a3 365 *
AnnaBridge 189:f392fc9709a3 366 * @param[in] obj The SPI peripheral to check
AnnaBridge 189:f392fc9709a3 367 * @return non-zero if the peripheral is currently transmitting
AnnaBridge 189:f392fc9709a3 368 */
AnnaBridge 189:f392fc9709a3 369 int spi_busy(spi_t *obj)
AnnaBridge 189:f392fc9709a3 370 {
AnnaBridge 189:f392fc9709a3 371 int status;
AnnaBridge 189:f392fc9709a3 372 struct spi_s *spiobj = SPI_S(obj);
AnnaBridge 189:f392fc9709a3 373 /* check whether or not the SPI is busy */
AnnaBridge 189:f392fc9709a3 374 status = ((spi_i2s_flag_get(spiobj->spi, SPI_FLAG_TRANS) != RESET) ? 1 : 0);
AnnaBridge 189:f392fc9709a3 375 return status;
AnnaBridge 189:f392fc9709a3 376 }
AnnaBridge 189:f392fc9709a3 377
AnnaBridge 189:f392fc9709a3 378 #endif