mbed library sources
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targets/hal/TARGET_STM/TARGET_NUCLEO_F103RB/spi_api.c
- Committer:
- mbed_official
- Date:
- 2013-12-12
- Revision:
- 56:99eb381a3269
- Parent:
- 52:a51c77007319
- Child:
- 70:c1fbde68b492
File content as of revision 56:99eb381a3269:
/* mbed Microcontroller Library * Copyright (c) 2006-2013 ARM Limited * * 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 "spi_api.h" #if DEVICE_SPI #include <math.h> #include "cmsis.h" #include "pinmap.h" #include "error.h" static const PinMap PinMap_SPI_MOSI[] = { {PA_7, SPI_1, STM_PIN_DATA(GPIO_Mode_AF_PP, 0)}, {PB_5, SPI_1, STM_PIN_DATA(GPIO_Mode_AF_PP, 1)}, // Remap {NC, NC, 0} }; static const PinMap PinMap_SPI_MISO[] = { {PA_6, SPI_1, STM_PIN_DATA(GPIO_Mode_AF_PP, 0)}, {PB_4, SPI_1, STM_PIN_DATA(GPIO_Mode_AF_PP, 1)}, // Remap {NC, NC, 0} }; static const PinMap PinMap_SPI_SCLK[] = { {PA_5, SPI_1, STM_PIN_DATA(GPIO_Mode_AF_PP, 0)}, {PB_3, SPI_1, STM_PIN_DATA(GPIO_Mode_AF_PP, 1)}, // Remap {NC, NC, 0} }; // Only used in Slave mode static const PinMap PinMap_SPI_SSEL[] = { {PB_6, SPI_1, STM_PIN_DATA(GPIO_Mode_IN_FLOATING, 0)}, // Generic IO, not real H/W NSS pin //{PA_4, SPI_1, STM_PIN_DATA(GPIO_Mode_IN_FLOATING, 0)}, //{PA_15, SPI_1, STM_PIN_DATA(GPIO_Mode_IN_FLOATING, 1)}, // Remap {NC, NC, 0} }; static void init_spi(spi_t *obj) { SPI_TypeDef *spi = (SPI_TypeDef *)(obj->spi); SPI_InitTypeDef SPI_InitStructure; SPI_Cmd(spi, DISABLE); SPI_InitStructure.SPI_Mode = obj->mode; SPI_InitStructure.SPI_NSS = obj->nss; SPI_InitStructure.SPI_Direction = SPI_Direction_2Lines_FullDuplex; SPI_InitStructure.SPI_DataSize = obj->bits; SPI_InitStructure.SPI_CPOL = obj->cpol; SPI_InitStructure.SPI_CPHA = obj->cpha; SPI_InitStructure.SPI_BaudRatePrescaler = obj->br_presc; SPI_InitStructure.SPI_FirstBit = SPI_FirstBit_MSB; SPI_InitStructure.SPI_CRCPolynomial = 7; SPI_Init(spi, &SPI_InitStructure); SPI_Cmd(spi, ENABLE); } void spi_init(spi_t *obj, PinName mosi, PinName miso, PinName sclk, PinName ssel) { // Determine the SPI to use 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); SPIName spi_data = (SPIName)pinmap_merge(spi_mosi, spi_miso); SPIName spi_cntl = (SPIName)pinmap_merge(spi_sclk, spi_ssel); obj->spi = (SPIName)pinmap_merge(spi_data, spi_cntl); if (obj->spi == (SPIName)NC) { error("SPI pinout mapping failed"); } // Enable SPI clock if (obj->spi == SPI_1) { RCC_APB2PeriphClockCmd(RCC_APB2Periph_SPI1, ENABLE); } if (obj->spi == SPI_2) { RCC_APB1PeriphClockCmd(RCC_APB1Periph_SPI2, ENABLE); } // Configure the SPI pins pinmap_pinout(mosi, PinMap_SPI_MOSI); pinmap_pinout(miso, PinMap_SPI_MISO); pinmap_pinout(sclk, PinMap_SPI_SCLK); // Save new values obj->bits = SPI_DataSize_8b; obj->cpol = SPI_CPOL_Low; obj->cpha = SPI_CPHA_1Edge; obj->br_presc = SPI_BaudRatePrescaler_64; // Closest to 1MHz (72MHz/64 = 1.125MHz) if (ssel == NC) { // Master obj->mode = SPI_Mode_Master; obj->nss = SPI_NSS_Soft; } else { // Slave pinmap_pinout(ssel, PinMap_SPI_SSEL); obj->mode = SPI_Mode_Slave; obj->nss = SPI_NSS_Soft; } init_spi(obj); } void spi_free(spi_t *obj) { SPI_TypeDef *spi = (SPI_TypeDef *)(obj->spi); SPI_I2S_DeInit(spi); } void spi_format(spi_t *obj, int bits, int mode, int slave) { // Save new values if (bits == 8) { obj->bits = SPI_DataSize_8b; } else { obj->bits = SPI_DataSize_16b; } switch (mode) { case 0: obj->cpol = SPI_CPOL_Low; obj->cpha = SPI_CPHA_1Edge; break; case 1: obj->cpol = SPI_CPOL_Low; obj->cpha = SPI_CPHA_2Edge; break; case 2: obj->cpol = SPI_CPOL_High; obj->cpha = SPI_CPHA_1Edge; break; default: obj->cpol = SPI_CPOL_High; obj->cpha = SPI_CPHA_2Edge; break; } if (slave == 0) { obj->mode = SPI_Mode_Master; obj->nss = SPI_NSS_Soft; } else { obj->mode = SPI_Mode_Slave; obj->nss = SPI_NSS_Hard; } init_spi(obj); } void spi_frequency(spi_t *obj, int hz) { // Get SPI clock frequency uint32_t PCLK = SystemCoreClock >> 1; // Choose the baud rate divisor (between 2 and 256) uint32_t divisor = PCLK / hz; // Find the nearest power-of-2 divisor = (divisor > 0 ? divisor-1 : 0); divisor |= divisor >> 1; divisor |= divisor >> 2; divisor |= divisor >> 4; divisor |= divisor >> 8; divisor |= divisor >> 16; divisor++; uint32_t baud_rate = __builtin_ffs(divisor) - 2; // Save new value obj->br_presc = ((baud_rate > 7) ? (7 << 3) : (baud_rate << 3)); init_spi(obj); } static inline int ssp_readable(spi_t *obj) { int status; SPI_TypeDef *spi = (SPI_TypeDef *)(obj->spi); // Check if data is received status = ((SPI_I2S_GetFlagStatus(spi, SPI_I2S_FLAG_RXNE) != RESET) ? 1 : 0); return status; } static inline int ssp_writeable(spi_t *obj) { int status; SPI_TypeDef *spi = (SPI_TypeDef *)(obj->spi); // Check if data is transmitted status = ((SPI_I2S_GetFlagStatus(spi, SPI_I2S_FLAG_TXE) != RESET) ? 1 : 0); return status; } static inline void ssp_write(spi_t *obj, int value) { SPI_TypeDef *spi = (SPI_TypeDef *)(obj->spi); while (!ssp_writeable(obj)); SPI_I2S_SendData(spi, (uint16_t)value); } static inline int ssp_read(spi_t *obj) { SPI_TypeDef *spi = (SPI_TypeDef *)(obj->spi); while (!ssp_readable(obj)); return (int)SPI_I2S_ReceiveData(spi); } static inline int ssp_busy(spi_t *obj) { int status; SPI_TypeDef *spi = (SPI_TypeDef *)(obj->spi); status = ((SPI_I2S_GetFlagStatus(spi, SPI_I2S_FLAG_BSY) != RESET) ? 1 : 0); return status; } int spi_master_write(spi_t *obj, int value) { ssp_write(obj, value); return ssp_read(obj); } int spi_slave_receive(spi_t *obj) { return (ssp_readable(obj) && !ssp_busy(obj)) ? (1) : (0); }; int spi_slave_read(spi_t *obj) { SPI_TypeDef *spi = (SPI_TypeDef *)(obj->spi); return (int)SPI_I2S_ReceiveData(spi); } void spi_slave_write(spi_t *obj, int value) { SPI_TypeDef *spi = (SPI_TypeDef *)(obj->spi); while (!ssp_writeable(obj)); SPI_I2S_SendData(spi, (uint16_t)value); } int spi_busy(spi_t *obj) { return ssp_busy(obj); } #endif