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mbed library sources

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Superseded

This library was superseded by mbed-dev - https://os.mbed.com/users/mbed_official/code/mbed-dev/.

Development branch of the mbed library sources. This library is kept in synch with the latest changes from the mbed SDK and it is not guaranteed to work.

If you are looking for a stable and tested release, please import one of the official mbed library releases:

Import librarymbed

The official Mbed 2 C/C++ SDK provides the software platform and libraries to build your applications.

Last commit 20 Feb 2019 by mbed official

targets/hal/TARGET_Freescale/TARGET_K20XX/spi_api.c@552:a1b9575155a3, 2015-05-27 (annotated)

Committer:
mbed_official
Date:
Wed May 27 13:30:08 2015 +0100
Revision:
552:a1b9575155a3
Parent:
445:3312ed629f01
Child:
620:49241b7c6da5
Synchronized with git revision a74a8f14fd8c4bf3dc09980c4bf9498ebcf4c207



Full URL: https://github.com/mbedmicro/mbed/commit/a74a8f14fd8c4bf3dc09980c4bf9498ebcf4c207/

Who changed what in which revision?

UserRevisionLine numberNew contents of line
mbed_official 445:3312ed629f01 1 /* mbed Microcontroller Library
mbed_official 445:3312ed629f01 2 * Copyright (c) 2015 ARM Limited
mbed_official 445:3312ed629f01 3 *
mbed_official 445:3312ed629f01 4 * Licensed under the Apache License, Version 2.0 (the "License");
mbed_official 445:3312ed629f01 5 * you may not use this file except in compliance with the License.
mbed_official 445:3312ed629f01 6 * You may obtain a copy of the License at
mbed_official 445:3312ed629f01 7 *
mbed_official 445:3312ed629f01 8 * http://www.apache.org/licenses/LICENSE-2.0
mbed_official 445:3312ed629f01 9 *
mbed_official 445:3312ed629f01 10 * Unless required by applicable law or agreed to in writing, software
mbed_official 445:3312ed629f01 11 * distributed under the License is distributed on an "AS IS" BASIS,
mbed_official 445:3312ed629f01 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
mbed_official 445:3312ed629f01 13 * See the License for the specific language governing permissions and
mbed_official 445:3312ed629f01 14 * limitations under the License.
mbed_official 445:3312ed629f01 15 */
mbed_official 445:3312ed629f01 16 #include "mbed_assert.h"
mbed_official 445:3312ed629f01 17 #include "spi_api.h"
mbed_official 445:3312ed629f01 18
mbed_official 445:3312ed629f01 19 #include <math.h>
mbed_official 445:3312ed629f01 20
mbed_official 445:3312ed629f01 21 #include "cmsis.h"
mbed_official 445:3312ed629f01 22 #include "pinmap.h"
mbed_official 445:3312ed629f01 23 #include "clk_freqs.h"
mbed_official 445:3312ed629f01 24 #include "PeripheralPins.h"
mbed_official 445:3312ed629f01 25
mbed_official 445:3312ed629f01 26 void spi_init(spi_t *obj, PinName mosi, PinName miso, PinName sclk, PinName ssel) {
mbed_official 445:3312ed629f01 27 // determine the SPI to use
mbed_official 445:3312ed629f01 28 SPIName spi_mosi = (SPIName)pinmap_peripheral(mosi, PinMap_SPI_MOSI);
mbed_official 445:3312ed629f01 29 SPIName spi_miso = (SPIName)pinmap_peripheral(miso, PinMap_SPI_MISO);
mbed_official 445:3312ed629f01 30 SPIName spi_sclk = (SPIName)pinmap_peripheral(sclk, PinMap_SPI_SCLK);
mbed_official 445:3312ed629f01 31 SPIName spi_ssel = (SPIName)pinmap_peripheral(ssel, PinMap_SPI_SSEL);
mbed_official 445:3312ed629f01 32 SPIName spi_data = (SPIName)pinmap_merge(spi_mosi, spi_miso);
mbed_official 445:3312ed629f01 33 SPIName spi_cntl = (SPIName)pinmap_merge(spi_sclk, spi_ssel);
mbed_official 445:3312ed629f01 34
mbed_official 445:3312ed629f01 35 obj->spi = (SPI_Type*)pinmap_merge(spi_data, spi_cntl);
mbed_official 445:3312ed629f01 36 MBED_ASSERT((int)obj->spi != NC);
mbed_official 445:3312ed629f01 37
mbed_official 445:3312ed629f01 38 SIM->SCGC5 |= SIM_SCGC5_PORTC_MASK | SIM_SCGC5_PORTD_MASK;
mbed_official 445:3312ed629f01 39 SIM->SCGC6 |= SIM_SCGC6_SPI0_MASK;
mbed_official 445:3312ed629f01 40
mbed_official 445:3312ed629f01 41 obj->spi->MCR &= ~(SPI_MCR_MDIS_MASK | SPI_MCR_HALT_MASK);
mbed_official 445:3312ed629f01 42 //obj->spi->MCR |= SPI_MCR_DIS_RXF_MASK | SPI_MCR_DIS_TXF_MASK;
mbed_official 445:3312ed629f01 43
mbed_official 445:3312ed629f01 44 // not halt in the debug mode
mbed_official 445:3312ed629f01 45 obj->spi->SR |= SPI_SR_EOQF_MASK;
mbed_official 445:3312ed629f01 46
mbed_official 445:3312ed629f01 47 // pin out the spi pins
mbed_official 445:3312ed629f01 48 pinmap_pinout(mosi, PinMap_SPI_MOSI);
mbed_official 445:3312ed629f01 49 pinmap_pinout(miso, PinMap_SPI_MISO);
mbed_official 445:3312ed629f01 50 pinmap_pinout(sclk, PinMap_SPI_SCLK);
mbed_official 445:3312ed629f01 51 if (ssel != NC) {
mbed_official 445:3312ed629f01 52 pinmap_pinout(ssel, PinMap_SPI_SSEL);
mbed_official 445:3312ed629f01 53 }
mbed_official 445:3312ed629f01 54 }
mbed_official 445:3312ed629f01 55
mbed_official 445:3312ed629f01 56 void spi_free(spi_t *obj) {
mbed_official 445:3312ed629f01 57 // [TODO]
mbed_official 445:3312ed629f01 58 }
mbed_official 445:3312ed629f01 59 void spi_format(spi_t *obj, int bits, int mode, int slave) {
mbed_official 445:3312ed629f01 60 MBED_ASSERT((bits > 4) || (bits < 16));
mbed_official 445:3312ed629f01 61 MBED_ASSERT((mode >= 0) && (mode <= 3));
mbed_official 445:3312ed629f01 62
mbed_official 445:3312ed629f01 63 uint32_t polarity = (mode & 0x2) ? 1 : 0;
mbed_official 445:3312ed629f01 64 uint32_t phase = (mode & 0x1) ? 1 : 0;
mbed_official 445:3312ed629f01 65
mbed_official 445:3312ed629f01 66 // set master/slave
mbed_official 445:3312ed629f01 67 obj->spi->MCR &= ~SPI_MCR_MSTR_MASK;
mbed_official 445:3312ed629f01 68 obj->spi->MCR |= ((!slave) << SPI_MCR_MSTR_SHIFT);
mbed_official 445:3312ed629f01 69
mbed_official 445:3312ed629f01 70 // CTAR0 is used
mbed_official 445:3312ed629f01 71 obj->spi->CTAR[0] &= ~(SPI_CTAR_CPHA_MASK | SPI_CTAR_CPOL_MASK | SPI_CTAR_FMSZ_MASK);
mbed_official 445:3312ed629f01 72 obj->spi->CTAR[0] |= (polarity << SPI_CTAR_CPOL_SHIFT) | (phase << SPI_CTAR_CPHA_SHIFT) | ((bits - 1) << SPI_CTAR_FMSZ_SHIFT);
mbed_official 445:3312ed629f01 73 }
mbed_official 445:3312ed629f01 74
mbed_official 445:3312ed629f01 75 static const uint8_t baudrate_prescaler[] = {2,3,5,7};
mbed_official 445:3312ed629f01 76 static const uint16_t baudrate_scaler[] = {2,4,6,8,16,32,64,128,256,512,1024,2048,4096,8192,16384,32768};
mbed_official 445:3312ed629f01 77
mbed_official 445:3312ed629f01 78 void spi_frequency(spi_t *obj, int hz) {
mbed_official 445:3312ed629f01 79 uint32_t f_error = 0;
mbed_official 445:3312ed629f01 80 uint32_t p_error = 0xffffffff;
mbed_official 445:3312ed629f01 81 uint32_t ref = 0;
mbed_official 445:3312ed629f01 82 uint32_t br = 0;
mbed_official 445:3312ed629f01 83 uint32_t ref_spr = 0;
mbed_official 445:3312ed629f01 84 uint32_t ref_prescaler = 0;
mbed_official 445:3312ed629f01 85 uint32_t ref_dr = 0;
mbed_official 445:3312ed629f01 86
mbed_official 445:3312ed629f01 87 // bus clk
mbed_official 445:3312ed629f01 88 uint32_t PCLK = bus_frequency();
mbed_official 445:3312ed629f01 89
mbed_official 445:3312ed629f01 90 for (uint32_t i = 0; i < 4; i++) {
mbed_official 445:3312ed629f01 91 for (br = 0; br <= 15; br++) {
mbed_official 445:3312ed629f01 92 for (uint32_t dr = 0; dr < 2; dr++) {
mbed_official 445:3312ed629f01 93 ref = (PCLK * (1U + dr) / baudrate_prescaler[i]) / baudrate_scaler[br];
mbed_official 445:3312ed629f01 94 if (ref > (uint32_t)hz)
mbed_official 445:3312ed629f01 95 continue;
mbed_official 445:3312ed629f01 96 f_error = hz - ref;
mbed_official 445:3312ed629f01 97 if (f_error < p_error) {
mbed_official 445:3312ed629f01 98 ref_spr = br;
mbed_official 445:3312ed629f01 99 ref_prescaler = i;
mbed_official 445:3312ed629f01 100 ref_dr = dr;
mbed_official 445:3312ed629f01 101 p_error = f_error;
mbed_official 445:3312ed629f01 102 }
mbed_official 445:3312ed629f01 103 }
mbed_official 445:3312ed629f01 104 }
mbed_official 445:3312ed629f01 105 }
mbed_official 445:3312ed629f01 106
mbed_official 445:3312ed629f01 107 // set PBR and BR
mbed_official 445:3312ed629f01 108 obj->spi->CTAR[0] &= ~(SPI_CTAR_PBR_MASK | SPI_CTAR_BR_MASK | SPI_CTAR_DBR_MASK);
mbed_official 445:3312ed629f01 109 obj->spi->CTAR[0] |= (ref_prescaler << SPI_CTAR_PBR_SHIFT) | (ref_spr << SPI_CTAR_BR_SHIFT) | (ref_dr << SPI_CTAR_DBR_SHIFT);
mbed_official 445:3312ed629f01 110 }
mbed_official 445:3312ed629f01 111
mbed_official 445:3312ed629f01 112 static inline int spi_writeable(spi_t *obj) {
mbed_official 445:3312ed629f01 113 return (obj->spi->SR & SPI_SR_TFFF_MASK) ? 1 : 0;
mbed_official 445:3312ed629f01 114 }
mbed_official 445:3312ed629f01 115
mbed_official 445:3312ed629f01 116 static inline int spi_readable(spi_t *obj) {
mbed_official 445:3312ed629f01 117 return (obj->spi->SR & SPI_SR_RFDF_MASK) ? 1 : 0;
mbed_official 445:3312ed629f01 118 }
mbed_official 445:3312ed629f01 119
mbed_official 445:3312ed629f01 120 int spi_master_write(spi_t *obj, int value) {
mbed_official 445:3312ed629f01 121 //clear RX buffer flag
mbed_official 445:3312ed629f01 122 obj->spi->SR |= SPI_SR_RFDF_MASK;
mbed_official 445:3312ed629f01 123 // wait tx buffer empty
mbed_official 445:3312ed629f01 124 while(!spi_writeable(obj));
mbed_official 445:3312ed629f01 125 obj->spi->PUSHR = SPI_PUSHR_TXDATA(value & 0xffff) /*| SPI_PUSHR_EOQ_MASK*/;
mbed_official 445:3312ed629f01 126
mbed_official 445:3312ed629f01 127 // wait rx buffer full
mbed_official 445:3312ed629f01 128 while (!spi_readable(obj));
mbed_official 445:3312ed629f01 129 return obj->spi->POPR;
mbed_official 445:3312ed629f01 130 }
mbed_official 445:3312ed629f01 131
mbed_official 445:3312ed629f01 132 int spi_slave_receive(spi_t *obj) {
mbed_official 445:3312ed629f01 133 return spi_readable(obj);
mbed_official 445:3312ed629f01 134 }
mbed_official 445:3312ed629f01 135
mbed_official 445:3312ed629f01 136 int spi_slave_read(spi_t *obj) {
mbed_official 445:3312ed629f01 137 obj->spi->SR |= SPI_SR_RFDF_MASK;
mbed_official 445:3312ed629f01 138 return obj->spi->POPR;
mbed_official 445:3312ed629f01 139 }
mbed_official 445:3312ed629f01 140
mbed_official 445:3312ed629f01 141 void spi_slave_write(spi_t *obj, int value) {
mbed_official 445:3312ed629f01 142 while (!spi_writeable(obj));
mbed_official 445:3312ed629f01 143 }