+++ /dev/null
-/* 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 "mbed_assert.h"
-#include "spi_api.h"
-
-#include <math.h>
-
-#include "cmsis.h"
-#include "pinmap.h"
-
-static const PinMap PinMap_SPI_SCLK[] = {
- {PTC3, SPI_1, 2},
- {PTC5, SPI_0, 2},
- {PTD1, SPI_0, 2},
- {PTD5, SPI_1, 2},
- {NC , NC , 0}
-};
-
-static const PinMap PinMap_SPI_MOSI[] = {
- {PTB16, SPI_1, 2},
- {PTB17, SPI_1, 5},
- {PTC6, SPI_0, 2},
- {PTC7, SPI_0, 5},
- {PTD2, SPI_0, 2},
- {PTD3, SPI_0, 5},
- {PTD6, SPI_1, 2},
- {PTD7, SPI_1, 5},
- {PTE1, SPI_1, 2},
- {NC , NC , 0}
-};
-
-static const PinMap PinMap_SPI_MISO[] = {
- {PTB16, SPI_1, 5},
- {PTB17, SPI_1, 2},
- {PTC6, SPI_0, 5},
- {PTC7, SPI_0, 2},
- {PTD2, SPI_0, 5},
- {PTD3, SPI_0, 2},
- {PTD6, SPI_1, 5},
- {PTD7, SPI_1, 2},
- {PTE0, SPI_1, 2},
- {PTE1, SPI_1, 5},
- {NC , NC , 0}
-};
-
-static const PinMap PinMap_SPI_SSEL[] = {
- {PTC4, SPI_0, 2},
- {PTD0, SPI_0, 2},
- {PTD4, SPI_1, 2},
- {NC , NC , 0}
-};
-
-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 = (SPI_Type*)pinmap_merge(spi_data, spi_cntl);
- MBED_ASSERT((int)obj->spi != NC);
-
- // enable power and clocking
- switch ((int)obj->spi) {
- case SPI_0: SIM->SCGC5 |= 1 << 13; SIM->SCGC4 |= 1 << 22; break;
- case SPI_1: SIM->SCGC5 |= 1 << 13; SIM->SCGC4 |= 1 << 23; break;
- }
-
- // set default format and frequency
- if (ssel == NC) {
- spi_format(obj, 8, 0, 0); // 8 bits, mode 0, master
- } else {
- spi_format(obj, 8, 0, 1); // 8 bits, mode 0, slave
- }
- spi_frequency(obj, 1000000);
-
- // enable SPI
- obj->spi->C1 |= SPI_C1_SPE_MASK;
- obj->spi->C2 &= ~SPI_C2_SPIMODE_MASK; //8bit
-
- // pin out the spi pins
- pinmap_pinout(mosi, PinMap_SPI_MOSI);
- pinmap_pinout(miso, PinMap_SPI_MISO);
- pinmap_pinout(sclk, PinMap_SPI_SCLK);
- if (ssel != NC) {
- pinmap_pinout(ssel, PinMap_SPI_SSEL);
- }
-}
-
-void spi_free(spi_t *obj) {
- // [TODO]
-}
-
-void spi_format(spi_t *obj, int bits, int mode, int slave) {
- MBED_ASSERT((bits == 8) || (bits == 16));
- MBED_ASSERT((mode >= 0) && (mode <= 3));
-
- uint8_t polarity = (mode & 0x2) ? 1 : 0;
- uint8_t phase = (mode & 0x1) ? 1 : 0;
- uint8_t c1_data = ((!slave) << 4) | (polarity << 3) | (phase << 2);
-
- // clear MSTR, CPOL and CPHA bits
- obj->spi->C1 &= ~(0x7 << 2);
-
- // write new value
- obj->spi->C1 |= c1_data;
- if (bits == 8) {
- obj->spi->C2 &= ~SPI_C2_SPIMODE_MASK;
- } else {
- obj->spi->C2 |= SPI_C2_SPIMODE_MASK;
- }
-}
-
-void spi_frequency(spi_t *obj, int hz) {
- uint32_t error = 0;
- uint32_t p_error = 0xffffffff;
- uint32_t ref = 0;
- uint8_t spr = 0;
- uint8_t ref_spr = 0;
- uint8_t ref_prescaler = 0;
-
- // bus clk
- uint32_t PCLK = SystemCoreClock / (((SIM->CLKDIV1 & SIM_CLKDIV1_OUTDIV4_MASK) >> SIM_CLKDIV1_OUTDIV4_SHIFT) + 1);
- uint8_t prescaler = 1;
- uint8_t divisor = 2;
-
- for (prescaler = 1; prescaler <= 8; prescaler++) {
- divisor = 2;
- for (spr = 0; spr <= 8; spr++, divisor *= 2) {
- ref = PCLK / (prescaler*divisor);
- if (ref > (uint32_t)hz)
- continue;
- error = hz - ref;
- if (error < p_error) {
- ref_spr = spr;
- ref_prescaler = prescaler - 1;
- p_error = error;
- }
- }
- }
-
- // set SPPR and SPR
- obj->spi->BR = ((ref_prescaler & 0x7) << 4) | (ref_spr & 0xf);
-}
-
-static inline int spi_writeable(spi_t * obj) {
- return (obj->spi->S & SPI_S_SPTEF_MASK) ? 1 : 0;
-}
-
-static inline int spi_readable(spi_t * obj) {
- return (obj->spi->S & SPI_S_SPRF_MASK) ? 1 : 0;
-}
-
-int spi_master_write(spi_t *obj, int value) {
- int ret;
- if (obj->spi->C2 & SPI_C2_SPIMODE_MASK) {
- // 16bit
- while(!spi_writeable(obj));
- obj->spi->DL = (value & 0xff);
- obj->spi->DH = ((value >> 8) & 0xff);
-
- // wait rx buffer full
- while (!spi_readable(obj));
- ret = obj->spi->DH;
- ret = (ret << 8) | obj->spi->DL;
- } else {
- //8bit
- while(!spi_writeable(obj));
- obj->spi->DL = (value & 0xff);
-
- // wait rx buffer full
- while (!spi_readable(obj));
- ret = (obj->spi->DL & 0xff);
- }
-
- return ret;
-}
-
-int spi_slave_receive(spi_t *obj) {
- return spi_readable(obj);
-}
-
-int spi_slave_read(spi_t *obj) {
- int ret;
- if (obj->spi->C2 & SPI_C2_SPIMODE_MASK) {
- ret = obj->spi->DH;
- ret = ((ret << 8) | obj->spi->DL);
- } else {
- ret = obj->spi->DL;
- }
- return ret;
-}
-
-void spi_slave_write(spi_t *obj, int value) {
- while (!spi_writeable(obj));
- if (obj->spi->C2 & SPI_C2_SPIMODE_MASK) {
- obj->spi->DL = (value & 0xff);
- obj->spi->DH = ((value >> 8) & 0xff);
- } else {
- obj->spi->DL = value;
- }
-
-}