mirror of https://github.com/ARMmbed/mbed-os.git
[STM32F3xx] Change SPI clock selection
Update of STM32F3 family CPI clock selection algo. Maximum SPI clock is obtained from APB domain clock (based on HAL API). Then algo sets maximum frequency available below requested frequency Signed-off-by: Erwan GOURIOU <frq07517@st.com>pull/2013/head
Erwan GOURIOU
parent
837cb78b39
commit
c87ff7872a
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@ -28,6 +28,7 @@
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*******************************************************************************
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*******************************************************************************
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*/
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*/
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#include "mbed_assert.h"
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#include "mbed_assert.h"
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#include "mbed_error.h"
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#include "spi_api.h"
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#include "spi_api.h"
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#if DEVICE_SPI
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#if DEVICE_SPI
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@ -195,86 +196,52 @@ void spi_format(spi_t *obj, int bits, int mode, int slave)
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init_spi(obj);
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init_spi(obj);
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}
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}
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static const uint16_t baudrate_prescaler_table[] = {SPI_BAUDRATEPRESCALER_2,
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SPI_BAUDRATEPRESCALER_4,
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SPI_BAUDRATEPRESCALER_8,
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SPI_BAUDRATEPRESCALER_16,
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SPI_BAUDRATEPRESCALER_32,
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SPI_BAUDRATEPRESCALER_64,
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SPI_BAUDRATEPRESCALER_128,
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SPI_BAUDRATEPRESCALER_256};
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void spi_frequency(spi_t *obj, int hz)
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void spi_frequency(spi_t *obj, int hz)
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{
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{
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#if defined(TARGET_STM32F334C8)
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int spi_hz = 0;
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// Values depend of APB2CLK : 64 MHz if HSI is used, 72 MHz if HSE is used
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uint8_t prescaler_rank = 0;
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if (hz < 500000) {
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obj->br_presc = SPI_BAUDRATEPRESCALER_256; // 250 kHz - 281 kHz
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/* Get source clock depending on SPI instance */
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} else if ((hz >= 500000) && (hz < 1000000)) {
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switch ((int)obj->spi) {
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obj->br_presc = SPI_BAUDRATEPRESCALER_128; // 500 kHz - 563 kHz
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#if defined SPI1_BASE
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} else if ((hz >= 1000000) && (hz < 2000000)) {
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case SPI_1:
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obj->br_presc = SPI_BAUDRATEPRESCALER_64; // 1 MHz - 1.13 MHz
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/* SPI_1. Source CLK is PCKL2 */
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} else if ((hz >= 2000000) && (hz < 4000000)) {
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spi_hz = HAL_RCC_GetPCLK2Freq();
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obj->br_presc = SPI_BAUDRATEPRESCALER_32; // 2 MHz - 2.25 MHz
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break;
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} else if ((hz >= 4000000) && (hz < 8000000)) {
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#endif
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obj->br_presc = SPI_BAUDRATEPRESCALER_16; // 4 MHz - 4.5 MHz
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#if defined SPI2_BASE
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} else if ((hz >= 8000000) && (hz < 16000000)) {
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case SPI_2:
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obj->br_presc = SPI_BAUDRATEPRESCALER_8; // 8 MHz - 9 MHz
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#endif
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} else if ((hz >= 16000000) && (hz < 32000000)) {
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#if defined SPI3_BASE
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obj->br_presc = SPI_BAUDRATEPRESCALER_4; // 16 MHz - 18 MHz
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case SPI_3:
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} else { // >= 32000000
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#endif
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obj->br_presc = SPI_BAUDRATEPRESCALER_2; // 32 MHz - 36 MHz
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/* SPI_2 and SPI_3. Source CLK is PCKL1 */
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}
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spi_hz = HAL_RCC_GetPCLK1Freq();
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#elif defined(TARGET_STM32F302R8)
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break;
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if (hz < 250000) {
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default:
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obj->br_presc = SPI_BAUDRATEPRESCALER_256; // 125 kHz - 141 kHz
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error("SPI instance not set");
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} else if ((hz >= 250000) && (hz < 500000)) {
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obj->br_presc = SPI_BAUDRATEPRESCALER_128; // 250 kHz - 280 kHz
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} else if ((hz >= 500000) && (hz < 1000000)) {
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obj->br_presc = SPI_BAUDRATEPRESCALER_64; // 500 kHz - 560 kHz
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} else if ((hz >= 1000000) && (hz < 2000000)) {
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obj->br_presc = SPI_BAUDRATEPRESCALER_32; // 1 MHz - 1.13 MHz
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} else if ((hz >= 2000000) && (hz < 4000000)) {
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obj->br_presc = SPI_BAUDRATEPRESCALER_16; // 2 MHz - 2.25 MHz
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} else if ((hz >= 4000000) && (hz < 8000000)) {
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obj->br_presc = SPI_BAUDRATEPRESCALER_8; // 4 MHz - 4.5 MHz
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} else if ((hz >= 8000000) && (hz < 16000000)) {
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obj->br_presc = SPI_BAUDRATEPRESCALER_4; // 8 MHz - 9 MHz
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} else { // >= 16000000
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obj->br_presc = SPI_BAUDRATEPRESCALER_2; // 16 MHz - 18 MHz
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}
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}
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#else
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/* Define pre-scaler in order to get highest available frequency below requested frequency */
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// Values depend of APB1CLK and APB2CLK : 32 MHz if HSI is used, 36 MHz if HSE is used
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while ((spi_hz > hz) && (prescaler_rank < sizeof(baudrate_prescaler_table)/sizeof(baudrate_prescaler_table[0]))){
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if (obj->spi == SPI_1) {
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spi_hz = spi_hz / 2;
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if (hz < 500000) {
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prescaler_rank++;
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obj->br_presc = SPI_BAUDRATEPRESCALER_256; // 250 kHz - 280 kHz
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}
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} else if ((hz >= 500000) && (hz < 1000000)) {
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obj->br_presc = SPI_BAUDRATEPRESCALER_128; // 500 kHz - 560 kHz
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if (prescaler_rank <= sizeof(baudrate_prescaler_table)/sizeof(baudrate_prescaler_table[0])) {
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} else if ((hz >= 1000000) && (hz < 2000000)) {
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obj->br_presc = baudrate_prescaler_table[prescaler_rank-1];
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obj->br_presc = SPI_BAUDRATEPRESCALER_64; // 1 MHz - 1.13 MHz
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} else {
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} else if ((hz >= 2000000) && (hz < 4000000)) {
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error("Couldn't setup requested SPI frequency");
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obj->br_presc = SPI_BAUDRATEPRESCALER_32; // 2 MHz - 2.25 MHz
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}
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} else if ((hz >= 4000000) && (hz < 8000000)) {
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obj->br_presc = SPI_BAUDRATEPRESCALER_16; // 4 MHz - 4.5 MHz
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} else if ((hz >= 8000000) && (hz < 16000000)) {
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obj->br_presc = SPI_BAUDRATEPRESCALER_8; // 8 MHz - 9 MHz
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} else if ((hz >= 16000000) && (hz < 32000000)) {
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obj->br_presc = SPI_BAUDRATEPRESCALER_4; // 16 MHz - 18 MHz
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} else { // >= 32000000
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obj->br_presc = SPI_BAUDRATEPRESCALER_2; // 32 MHz - 36 MHz
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}
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} else {
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if (hz < 250000) {
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obj->br_presc = SPI_BAUDRATEPRESCALER_256; // 125 kHz - 141 kHz
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} else if ((hz >= 250000) && (hz < 500000)) {
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obj->br_presc = SPI_BAUDRATEPRESCALER_128; // 250 kHz - 280 kHz
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} else if ((hz >= 500000) && (hz < 1000000)) {
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obj->br_presc = SPI_BAUDRATEPRESCALER_64; // 500 kHz - 560 kHz
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} else if ((hz >= 1000000) && (hz < 2000000)) {
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obj->br_presc = SPI_BAUDRATEPRESCALER_32; // 1 MHz - 1.13 MHz
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} else if ((hz >= 2000000) && (hz < 4000000)) {
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obj->br_presc = SPI_BAUDRATEPRESCALER_16; // 2 MHz - 2.25 MHz
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} else if ((hz >= 4000000) && (hz < 8000000)) {
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obj->br_presc = SPI_BAUDRATEPRESCALER_8; // 4 MHz - 4.5 MHz
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} else if ((hz >= 8000000) && (hz < 16000000)) {
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obj->br_presc = SPI_BAUDRATEPRESCALER_4; // 8 MHz - 9 MHz
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} else { // >= 16000000
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obj->br_presc = SPI_BAUDRATEPRESCALER_2; // 16 MHz - 18 MHz
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}
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}
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#endif
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init_spi(obj);
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init_spi(obj);
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}
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}
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