Ken Todotani / mbed-src

Important changes to repositories hosted on mbed.com

Mbed hosted mercurial repositories are deprecated and are due to be permanently deleted in July 2026.

To keep a copy of this software download the repository Zip archive or clone locally using Mercurial.

It is also possible to export all your personal repositories from the account settings page.

Fork of mbed-src by mbed official

targets/hal/TARGET_Freescale/TARGET_KLXX/TARGET_KL05Z/spi_api.c@82:0b31dbcd4769, 2014-01-31 (annotated)

Committer:
mbed_official
Date:
Fri Jan 31 10:00:06 2014 +0000
Revision:
82:0b31dbcd4769
Child:
227:7bd0639b8911
Synchronized with git revision 74409cbd593d1daab530a57baaa563f30b04b018



Full URL: https://github.com/mbedmicro/mbed/commit/74409cbd593d1daab530a57baaa563f30b04b018/

Who changed what in which revision?

UserRevisionLine numberNew contents of line
mbed_official 82:0b31dbcd4769 1 /* mbed Microcontroller Library
mbed_official 82:0b31dbcd4769 2 * Copyright (c) 2006-2013 ARM Limited
mbed_official 82:0b31dbcd4769 3 *
mbed_official 82:0b31dbcd4769 4 * Licensed under the Apache License, Version 2.0 (the "License");
mbed_official 82:0b31dbcd4769 5 * you may not use this file except in compliance with the License.
mbed_official 82:0b31dbcd4769 6 * You may obtain a copy of the License at
mbed_official 82:0b31dbcd4769 7 *
mbed_official 82:0b31dbcd4769 8 * http://www.apache.org/licenses/LICENSE-2.0
mbed_official 82:0b31dbcd4769 9 *
mbed_official 82:0b31dbcd4769 10 * Unless required by applicable law or agreed to in writing, software
mbed_official 82:0b31dbcd4769 11 * distributed under the License is distributed on an "AS IS" BASIS,
mbed_official 82:0b31dbcd4769 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
mbed_official 82:0b31dbcd4769 13 * See the License for the specific language governing permissions and
mbed_official 82:0b31dbcd4769 14 * limitations under the License.
mbed_official 82:0b31dbcd4769 15 */
mbed_official 82:0b31dbcd4769 16 #include "spi_api.h"
mbed_official 82:0b31dbcd4769 17
mbed_official 82:0b31dbcd4769 18 #include <math.h>
mbed_official 82:0b31dbcd4769 19
mbed_official 82:0b31dbcd4769 20 #include "cmsis.h"
mbed_official 82:0b31dbcd4769 21 #include "pinmap.h"
mbed_official 82:0b31dbcd4769 22 #include "error.h"
mbed_official 82:0b31dbcd4769 23
mbed_official 82:0b31dbcd4769 24 static const PinMap PinMap_SPI_SCLK[] = {
mbed_official 82:0b31dbcd4769 25 {PTB0, SPI_0, 3},
mbed_official 82:0b31dbcd4769 26 {NC , NC , 0}
mbed_official 82:0b31dbcd4769 27 };
mbed_official 82:0b31dbcd4769 28
mbed_official 82:0b31dbcd4769 29 static const PinMap PinMap_SPI_MOSI[] = {
mbed_official 82:0b31dbcd4769 30 {PTA7, SPI_0, 3},
mbed_official 82:0b31dbcd4769 31 {NC , NC , 0}
mbed_official 82:0b31dbcd4769 32 };
mbed_official 82:0b31dbcd4769 33
mbed_official 82:0b31dbcd4769 34 static const PinMap PinMap_SPI_MISO[] = {
mbed_official 82:0b31dbcd4769 35 {PTA6, SPI_0, 3},
mbed_official 82:0b31dbcd4769 36 {NC , NC , 0}
mbed_official 82:0b31dbcd4769 37 };
mbed_official 82:0b31dbcd4769 38
mbed_official 82:0b31dbcd4769 39 static const PinMap PinMap_SPI_SSEL[] = {
mbed_official 82:0b31dbcd4769 40 {PTA5, SPI_0, 3},
mbed_official 82:0b31dbcd4769 41 {NC , NC , 0}
mbed_official 82:0b31dbcd4769 42 };
mbed_official 82:0b31dbcd4769 43
mbed_official 82:0b31dbcd4769 44 void spi_init(spi_t *obj, PinName mosi, PinName miso, PinName sclk, PinName ssel) {
mbed_official 82:0b31dbcd4769 45 // determine the SPI to use
mbed_official 82:0b31dbcd4769 46 SPIName spi_mosi = (SPIName)pinmap_peripheral(mosi, PinMap_SPI_MOSI);
mbed_official 82:0b31dbcd4769 47 SPIName spi_miso = (SPIName)pinmap_peripheral(miso, PinMap_SPI_MISO);
mbed_official 82:0b31dbcd4769 48 SPIName spi_sclk = (SPIName)pinmap_peripheral(sclk, PinMap_SPI_SCLK);
mbed_official 82:0b31dbcd4769 49 SPIName spi_ssel = (SPIName)pinmap_peripheral(ssel, PinMap_SPI_SSEL);
mbed_official 82:0b31dbcd4769 50 SPIName spi_data = (SPIName)pinmap_merge(spi_mosi, spi_miso);
mbed_official 82:0b31dbcd4769 51 SPIName spi_cntl = (SPIName)pinmap_merge(spi_sclk, spi_ssel);
mbed_official 82:0b31dbcd4769 52
mbed_official 82:0b31dbcd4769 53 obj->spi = (SPI_Type*)pinmap_merge(spi_data, spi_cntl);
mbed_official 82:0b31dbcd4769 54 if ((int)obj->spi == NC) {
mbed_official 82:0b31dbcd4769 55 error("SPI pinout mapping failed");
mbed_official 82:0b31dbcd4769 56 }
mbed_official 82:0b31dbcd4769 57
mbed_official 82:0b31dbcd4769 58 // enable power and clocking
mbed_official 82:0b31dbcd4769 59 switch ((int)obj->spi) {
mbed_official 82:0b31dbcd4769 60 case SPI_0:
mbed_official 82:0b31dbcd4769 61 SIM->SCGC5 |= (SIM_SCGC5_PORTA_MASK | SIM_SCGC5_PORTB_MASK);
mbed_official 82:0b31dbcd4769 62 SIM->SCGC4 |= SIM_SCGC4_SPI0_MASK;
mbed_official 82:0b31dbcd4769 63 break;
mbed_official 82:0b31dbcd4769 64 }
mbed_official 82:0b31dbcd4769 65
mbed_official 82:0b31dbcd4769 66 // set default format and frequency
mbed_official 82:0b31dbcd4769 67 if (ssel == NC) {
mbed_official 82:0b31dbcd4769 68 spi_format(obj, 8, 0, 0); // 8 bits, mode 0, master
mbed_official 82:0b31dbcd4769 69 } else {
mbed_official 82:0b31dbcd4769 70 spi_format(obj, 8, 0, 1); // 8 bits, mode 0, slave
mbed_official 82:0b31dbcd4769 71 }
mbed_official 82:0b31dbcd4769 72 spi_frequency(obj, 1000000);
mbed_official 82:0b31dbcd4769 73
mbed_official 82:0b31dbcd4769 74 // enable SPI
mbed_official 82:0b31dbcd4769 75 obj->spi->C1 |= SPI_C1_SPE_MASK;
mbed_official 82:0b31dbcd4769 76
mbed_official 82:0b31dbcd4769 77 // pin out the spi pins
mbed_official 82:0b31dbcd4769 78 pinmap_pinout(mosi, PinMap_SPI_MOSI);
mbed_official 82:0b31dbcd4769 79 pinmap_pinout(miso, PinMap_SPI_MISO);
mbed_official 82:0b31dbcd4769 80 pinmap_pinout(sclk, PinMap_SPI_SCLK);
mbed_official 82:0b31dbcd4769 81 if (ssel != NC) {
mbed_official 82:0b31dbcd4769 82 pinmap_pinout(ssel, PinMap_SPI_SSEL);
mbed_official 82:0b31dbcd4769 83 }
mbed_official 82:0b31dbcd4769 84 }
mbed_official 82:0b31dbcd4769 85
mbed_official 82:0b31dbcd4769 86 void spi_free(spi_t *obj) {
mbed_official 82:0b31dbcd4769 87 // [TODO]
mbed_official 82:0b31dbcd4769 88 }
mbed_official 82:0b31dbcd4769 89 void spi_format(spi_t *obj, int bits, int mode, int slave) {
mbed_official 82:0b31dbcd4769 90 if (bits != 8) {
mbed_official 82:0b31dbcd4769 91 error("Only 8bits SPI supported");
mbed_official 82:0b31dbcd4769 92 }
mbed_official 82:0b31dbcd4769 93
mbed_official 82:0b31dbcd4769 94 if ((mode < 0) || (mode > 3)) {
mbed_official 82:0b31dbcd4769 95 error("SPI mode unsupported");
mbed_official 82:0b31dbcd4769 96 }
mbed_official 82:0b31dbcd4769 97
mbed_official 82:0b31dbcd4769 98 uint8_t polarity = (mode & 0x2) ? 1 : 0;
mbed_official 82:0b31dbcd4769 99 uint8_t phase = (mode & 0x1) ? 1 : 0;
mbed_official 82:0b31dbcd4769 100 uint8_t c1_data = ((!slave) << 4) | (polarity << 3) | (phase << 2);
mbed_official 82:0b31dbcd4769 101
mbed_official 82:0b31dbcd4769 102 // clear MSTR, CPOL and CPHA bits
mbed_official 82:0b31dbcd4769 103 obj->spi->C1 &= ~(0x7 << 2);
mbed_official 82:0b31dbcd4769 104
mbed_official 82:0b31dbcd4769 105 // write new value
mbed_official 82:0b31dbcd4769 106 obj->spi->C1 |= c1_data;
mbed_official 82:0b31dbcd4769 107 }
mbed_official 82:0b31dbcd4769 108
mbed_official 82:0b31dbcd4769 109 void spi_frequency(spi_t *obj, int hz) {
mbed_official 82:0b31dbcd4769 110 uint32_t error = 0;
mbed_official 82:0b31dbcd4769 111 uint32_t p_error = 0xffffffff;
mbed_official 82:0b31dbcd4769 112 uint32_t ref = 0;
mbed_official 82:0b31dbcd4769 113 uint8_t spr = 0;
mbed_official 82:0b31dbcd4769 114 uint8_t ref_spr = 0;
mbed_official 82:0b31dbcd4769 115 uint8_t ref_prescaler = 0;
mbed_official 82:0b31dbcd4769 116
mbed_official 82:0b31dbcd4769 117 // bus clk
mbed_official 82:0b31dbcd4769 118 uint32_t PCLK = SystemCoreClock / (((SIM->CLKDIV1 & SIM_CLKDIV1_OUTDIV4_MASK) >> SIM_CLKDIV1_OUTDIV4_SHIFT) + 1);
mbed_official 82:0b31dbcd4769 119 uint8_t prescaler = 1;
mbed_official 82:0b31dbcd4769 120 uint8_t divisor = 2;
mbed_official 82:0b31dbcd4769 121
mbed_official 82:0b31dbcd4769 122 for (prescaler = 1; prescaler <= 8; prescaler++) {
mbed_official 82:0b31dbcd4769 123 divisor = 2;
mbed_official 82:0b31dbcd4769 124 for (spr = 0; spr <= 8; spr++) {
mbed_official 82:0b31dbcd4769 125 ref = PCLK / (prescaler*divisor);
mbed_official 82:0b31dbcd4769 126 if (ref > (uint32_t)hz)
mbed_official 82:0b31dbcd4769 127 continue;
mbed_official 82:0b31dbcd4769 128 error = hz - ref;
mbed_official 82:0b31dbcd4769 129 if (error < p_error) {
mbed_official 82:0b31dbcd4769 130 ref_spr = spr;
mbed_official 82:0b31dbcd4769 131 ref_prescaler = prescaler - 1;
mbed_official 82:0b31dbcd4769 132 p_error = error;
mbed_official 82:0b31dbcd4769 133 }
mbed_official 82:0b31dbcd4769 134 divisor *= 2;
mbed_official 82:0b31dbcd4769 135 }
mbed_official 82:0b31dbcd4769 136 }
mbed_official 82:0b31dbcd4769 137
mbed_official 82:0b31dbcd4769 138 // set SPPR and SPR
mbed_official 82:0b31dbcd4769 139 obj->spi->BR = ((ref_prescaler & 0x7) << 4) | (ref_spr & 0xf);
mbed_official 82:0b31dbcd4769 140 }
mbed_official 82:0b31dbcd4769 141
mbed_official 82:0b31dbcd4769 142 static inline int spi_writeable(spi_t * obj) {
mbed_official 82:0b31dbcd4769 143 return (obj->spi->S & SPI_S_SPTEF_MASK) ? 1 : 0;
mbed_official 82:0b31dbcd4769 144 }
mbed_official 82:0b31dbcd4769 145
mbed_official 82:0b31dbcd4769 146 static inline int spi_readable(spi_t * obj) {
mbed_official 82:0b31dbcd4769 147 return (obj->spi->S & SPI_S_SPRF_MASK) ? 1 : 0;
mbed_official 82:0b31dbcd4769 148 }
mbed_official 82:0b31dbcd4769 149
mbed_official 82:0b31dbcd4769 150 int spi_master_write(spi_t *obj, int value) {
mbed_official 82:0b31dbcd4769 151 // wait tx buffer empty
mbed_official 82:0b31dbcd4769 152 while(!spi_writeable(obj));
mbed_official 82:0b31dbcd4769 153 obj->spi->D = (value & 0xff);
mbed_official 82:0b31dbcd4769 154
mbed_official 82:0b31dbcd4769 155 // wait rx buffer full
mbed_official 82:0b31dbcd4769 156 while (!spi_readable(obj));
mbed_official 82:0b31dbcd4769 157 return obj->spi->D & 0xff;
mbed_official 82:0b31dbcd4769 158 }
mbed_official 82:0b31dbcd4769 159
mbed_official 82:0b31dbcd4769 160 int spi_slave_receive(spi_t *obj) {
mbed_official 82:0b31dbcd4769 161 return spi_readable(obj);
mbed_official 82:0b31dbcd4769 162 }
mbed_official 82:0b31dbcd4769 163
mbed_official 82:0b31dbcd4769 164 int spi_slave_read(spi_t *obj) {
mbed_official 82:0b31dbcd4769 165 return obj->spi->D;
mbed_official 82:0b31dbcd4769 166 }
mbed_official 82:0b31dbcd4769 167
mbed_official 82:0b31dbcd4769 168 void spi_slave_write(spi_t *obj, int value) {
mbed_official 82:0b31dbcd4769 169 while (!spi_writeable(obj));
mbed_official 82:0b31dbcd4769 170 obj->spi->D = value;
mbed_official 82:0b31dbcd4769 171 }