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mbed SDK library sources

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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.

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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_KL46Z/spi_api.c@33:e214068ab66c, 2013-10-07 (annotated)

Committer:
mbed_official
Date:
Mon Oct 07 09:15:08 2013 +0100
Revision:
33:e214068ab66c
Parent:
31:42176bc3c368
Child:
44:2ce89a25b635
Synchronized with git revision 53edc82f7373bbfa01a161700524765f52fdb444

Who changed what in which revision?

UserRevisionLine numberNew contents of line
mbed_official 31:42176bc3c368 1 /* mbed Microcontroller Library
mbed_official 31:42176bc3c368 2 * Copyright (c) 2006-2013 ARM Limited
mbed_official 31:42176bc3c368 3 *
mbed_official 31:42176bc3c368 4 * Licensed under the Apache License, Version 2.0 (the "License");
mbed_official 31:42176bc3c368 5 * you may not use this file except in compliance with the License.
mbed_official 31:42176bc3c368 6 * You may obtain a copy of the License at
mbed_official 31:42176bc3c368 7 *
mbed_official 31:42176bc3c368 8 * http://www.apache.org/licenses/LICENSE-2.0
mbed_official 31:42176bc3c368 9 *
mbed_official 31:42176bc3c368 10 * Unless required by applicable law or agreed to in writing, software
mbed_official 31:42176bc3c368 11 * distributed under the License is distributed on an "AS IS" BASIS,
mbed_official 31:42176bc3c368 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
mbed_official 31:42176bc3c368 13 * See the License for the specific language governing permissions and
mbed_official 31:42176bc3c368 14 * limitations under the License.
mbed_official 31:42176bc3c368 15 */
mbed_official 31:42176bc3c368 16 #include "spi_api.h"
mbed_official 31:42176bc3c368 17
mbed_official 31:42176bc3c368 18 #include <math.h>
mbed_official 31:42176bc3c368 19
mbed_official 31:42176bc3c368 20 #include "cmsis.h"
mbed_official 31:42176bc3c368 21 #include "pinmap.h"
mbed_official 31:42176bc3c368 22 #include "error.h"
mbed_official 31:42176bc3c368 23
mbed_official 31:42176bc3c368 24 static const PinMap PinMap_SPI_SCLK[] = {
mbed_official 31:42176bc3c368 25 {PTA15, SPI_0, 2},
mbed_official 33:e214068ab66c 26 {PTB9, SPI_1, 2},
mbed_official 31:42176bc3c368 27 {PTB11, SPI_1, 2},
mbed_official 31:42176bc3c368 28 {PTC5, SPI_0, 2},
mbed_official 31:42176bc3c368 29 {PTD1, SPI_0, 2},
mbed_official 31:42176bc3c368 30 {PTD5, SPI_1, 2},
mbed_official 31:42176bc3c368 31 {PTE2, SPI_1, 2},
mbed_official 33:e214068ab66c 32 {PTE17, SPI_0, 2},
mbed_official 31:42176bc3c368 33 {NC , NC , 0}
mbed_official 31:42176bc3c368 34 };
mbed_official 31:42176bc3c368 35
mbed_official 31:42176bc3c368 36 static const PinMap PinMap_SPI_MOSI[] = {
mbed_official 31:42176bc3c368 37 {PTA16, SPI_0, 2},
mbed_official 31:42176bc3c368 38 {PTA17, SPI_0, 5},
mbed_official 31:42176bc3c368 39 {PTB16, SPI_1, 2},
mbed_official 31:42176bc3c368 40 {PTB17, SPI_1, 5},
mbed_official 31:42176bc3c368 41 {PTC6, SPI_0, 2},
mbed_official 31:42176bc3c368 42 {PTC7, SPI_0, 5},
mbed_official 31:42176bc3c368 43 {PTD2, SPI_0, 2},
mbed_official 31:42176bc3c368 44 {PTD3, SPI_0, 5},
mbed_official 31:42176bc3c368 45 {PTD6, SPI_1, 2},
mbed_official 31:42176bc3c368 46 {PTD7, SPI_1, 5},
mbed_official 31:42176bc3c368 47 {PTE1, SPI_1, 2},
mbed_official 31:42176bc3c368 48 {PTE3, SPI_1, 5},
mbed_official 33:e214068ab66c 49 {PTE18, SPI_0, 2},
mbed_official 33:e214068ab66c 50 {PTE19, SPI_0, 5},
mbed_official 31:42176bc3c368 51 {NC , NC , 0}
mbed_official 31:42176bc3c368 52 };
mbed_official 31:42176bc3c368 53
mbed_official 31:42176bc3c368 54 static const PinMap PinMap_SPI_MISO[] = {
mbed_official 31:42176bc3c368 55 {PTA16, SPI_0, 5},
mbed_official 31:42176bc3c368 56 {PTA17, SPI_0, 2},
mbed_official 31:42176bc3c368 57 {PTB16, SPI_1, 5},
mbed_official 31:42176bc3c368 58 {PTB17, SPI_1, 2},
mbed_official 31:42176bc3c368 59 {PTC6, SPI_0, 5},
mbed_official 31:42176bc3c368 60 {PTC7, SPI_0, 2},
mbed_official 31:42176bc3c368 61 {PTD2, SPI_0, 5},
mbed_official 31:42176bc3c368 62 {PTD3, SPI_0, 2},
mbed_official 31:42176bc3c368 63 {PTD6, SPI_1, 5},
mbed_official 31:42176bc3c368 64 {PTD7, SPI_1, 2},
mbed_official 31:42176bc3c368 65 {PTE1, SPI_1, 5},
mbed_official 31:42176bc3c368 66 {PTE3, SPI_1, 2},
mbed_official 33:e214068ab66c 67 {PTE18, SPI_0, 5},
mbed_official 33:e214068ab66c 68 {PTE19, SPI_0, 2},
mbed_official 31:42176bc3c368 69 {NC , NC , 0}
mbed_official 31:42176bc3c368 70 };
mbed_official 31:42176bc3c368 71
mbed_official 31:42176bc3c368 72 static const PinMap PinMap_SPI_SSEL[] = {
mbed_official 31:42176bc3c368 73 {PTA14, SPI_0, 2},
mbed_official 31:42176bc3c368 74 {PTB10, SPI_1, 2},
mbed_official 31:42176bc3c368 75 {PTC4, SPI_0, 2},
mbed_official 31:42176bc3c368 76 {PTD0, SPI_0, 2},
mbed_official 31:42176bc3c368 77 {PTD4, SPI_1, 2},
mbed_official 31:42176bc3c368 78 {PTE4, SPI_1, 2},
mbed_official 33:e214068ab66c 79 {PTE16, SPI_0, 2},
mbed_official 31:42176bc3c368 80 {NC , NC , 0}
mbed_official 31:42176bc3c368 81 };
mbed_official 31:42176bc3c368 82
mbed_official 31:42176bc3c368 83 void spi_init(spi_t *obj, PinName mosi, PinName miso, PinName sclk, PinName ssel) {
mbed_official 31:42176bc3c368 84 // determine the SPI to use
mbed_official 31:42176bc3c368 85 SPIName spi_mosi = (SPIName)pinmap_peripheral(mosi, PinMap_SPI_MOSI);
mbed_official 31:42176bc3c368 86 SPIName spi_miso = (SPIName)pinmap_peripheral(miso, PinMap_SPI_MISO);
mbed_official 31:42176bc3c368 87 SPIName spi_sclk = (SPIName)pinmap_peripheral(sclk, PinMap_SPI_SCLK);
mbed_official 31:42176bc3c368 88 SPIName spi_ssel = (SPIName)pinmap_peripheral(ssel, PinMap_SPI_SSEL);
mbed_official 31:42176bc3c368 89 SPIName spi_data = (SPIName)pinmap_merge(spi_mosi, spi_miso);
mbed_official 31:42176bc3c368 90 SPIName spi_cntl = (SPIName)pinmap_merge(spi_sclk, spi_ssel);
mbed_official 31:42176bc3c368 91
mbed_official 31:42176bc3c368 92 obj->spi = (SPI_Type*)pinmap_merge(spi_data, spi_cntl);
mbed_official 31:42176bc3c368 93 if ((int)obj->spi == NC) {
mbed_official 31:42176bc3c368 94 error("SPI pinout mapping failed");
mbed_official 31:42176bc3c368 95 }
mbed_official 31:42176bc3c368 96
mbed_official 31:42176bc3c368 97 // enable power and clocking
mbed_official 31:42176bc3c368 98 switch ((int)obj->spi) {
mbed_official 31:42176bc3c368 99 case SPI_0: SIM->SCGC5 |= 1 << 11; SIM->SCGC4 |= 1 << 22; break;
mbed_official 31:42176bc3c368 100 case SPI_1: SIM->SCGC5 |= 1 << 13; SIM->SCGC4 |= 1 << 23; break;
mbed_official 31:42176bc3c368 101 }
mbed_official 31:42176bc3c368 102
mbed_official 31:42176bc3c368 103 // set default format and frequency
mbed_official 31:42176bc3c368 104 if (ssel == NC) {
mbed_official 31:42176bc3c368 105 spi_format(obj, 8, 0, 0); // 8 bits, mode 0, master
mbed_official 31:42176bc3c368 106 } else {
mbed_official 31:42176bc3c368 107 spi_format(obj, 8, 0, 1); // 8 bits, mode 0, slave
mbed_official 31:42176bc3c368 108 }
mbed_official 31:42176bc3c368 109 spi_frequency(obj, 1000000);
mbed_official 31:42176bc3c368 110
mbed_official 31:42176bc3c368 111 // enable SPI
mbed_official 31:42176bc3c368 112 obj->spi->C1 |= SPI_C1_SPE_MASK;
mbed_official 31:42176bc3c368 113
mbed_official 31:42176bc3c368 114 // pin out the spi pins
mbed_official 31:42176bc3c368 115 pinmap_pinout(mosi, PinMap_SPI_MOSI);
mbed_official 31:42176bc3c368 116 pinmap_pinout(miso, PinMap_SPI_MISO);
mbed_official 31:42176bc3c368 117 pinmap_pinout(sclk, PinMap_SPI_SCLK);
mbed_official 31:42176bc3c368 118 if (ssel != NC) {
mbed_official 31:42176bc3c368 119 pinmap_pinout(ssel, PinMap_SPI_SSEL);
mbed_official 31:42176bc3c368 120 }
mbed_official 31:42176bc3c368 121 }
mbed_official 31:42176bc3c368 122
mbed_official 31:42176bc3c368 123 void spi_free(spi_t *obj) {
mbed_official 31:42176bc3c368 124 // [TODO]
mbed_official 31:42176bc3c368 125 }
mbed_official 31:42176bc3c368 126 void spi_format(spi_t *obj, int bits, int mode, int slave) {
mbed_official 31:42176bc3c368 127 if (bits != 8) {
mbed_official 31:42176bc3c368 128 error("Only 8bits SPI supported");
mbed_official 31:42176bc3c368 129 }
mbed_official 31:42176bc3c368 130
mbed_official 31:42176bc3c368 131 if ((mode < 0) || (mode > 3)) {
mbed_official 31:42176bc3c368 132 error("SPI mode unsupported");
mbed_official 31:42176bc3c368 133 }
mbed_official 31:42176bc3c368 134
mbed_official 31:42176bc3c368 135 uint8_t polarity = (mode & 0x2) ? 1 : 0;
mbed_official 31:42176bc3c368 136 uint8_t phase = (mode & 0x1) ? 1 : 0;
mbed_official 31:42176bc3c368 137 uint8_t c1_data = ((!slave) << 4) | (polarity << 3) | (phase << 2);
mbed_official 31:42176bc3c368 138
mbed_official 31:42176bc3c368 139 // clear MSTR, CPOL and CPHA bits
mbed_official 31:42176bc3c368 140 obj->spi->C1 &= ~(0x7 << 2);
mbed_official 31:42176bc3c368 141
mbed_official 31:42176bc3c368 142 // write new value
mbed_official 31:42176bc3c368 143 obj->spi->C1 |= c1_data;
mbed_official 31:42176bc3c368 144 }
mbed_official 31:42176bc3c368 145
mbed_official 31:42176bc3c368 146 void spi_frequency(spi_t *obj, int hz) {
mbed_official 31:42176bc3c368 147 uint32_t error = 0;
mbed_official 31:42176bc3c368 148 uint32_t p_error = 0xffffffff;
mbed_official 31:42176bc3c368 149 uint32_t ref = 0;
mbed_official 31:42176bc3c368 150 uint8_t spr = 0;
mbed_official 31:42176bc3c368 151 uint8_t ref_spr = 0;
mbed_official 31:42176bc3c368 152 uint8_t ref_prescaler = 0;
mbed_official 31:42176bc3c368 153
mbed_official 31:42176bc3c368 154 // bus clk
mbed_official 31:42176bc3c368 155 uint32_t PCLK = 48000000u;
mbed_official 31:42176bc3c368 156 uint8_t prescaler = 1;
mbed_official 31:42176bc3c368 157 uint8_t divisor = 2;
mbed_official 31:42176bc3c368 158
mbed_official 31:42176bc3c368 159 for (prescaler = 1; prescaler <= 8; prescaler++) {
mbed_official 31:42176bc3c368 160 divisor = 2;
mbed_official 31:42176bc3c368 161 for (spr = 0; spr <= 8; spr++, divisor *= 2) {
mbed_official 31:42176bc3c368 162 ref = PCLK / (prescaler*divisor);
mbed_official 31:42176bc3c368 163 if (ref > (uint32_t)hz)
mbed_official 31:42176bc3c368 164 continue;
mbed_official 31:42176bc3c368 165 error = hz - ref;
mbed_official 31:42176bc3c368 166 if (error < p_error) {
mbed_official 31:42176bc3c368 167 ref_spr = spr;
mbed_official 31:42176bc3c368 168 ref_prescaler = prescaler - 1;
mbed_official 31:42176bc3c368 169 p_error = error;
mbed_official 31:42176bc3c368 170 }
mbed_official 31:42176bc3c368 171 }
mbed_official 31:42176bc3c368 172 }
mbed_official 31:42176bc3c368 173
mbed_official 31:42176bc3c368 174 // set SPPR and SPR
mbed_official 31:42176bc3c368 175 obj->spi->BR = ((ref_prescaler & 0x7) << 4) | (ref_spr & 0xf);
mbed_official 31:42176bc3c368 176 }
mbed_official 31:42176bc3c368 177
mbed_official 31:42176bc3c368 178 static inline int spi_writeable(spi_t * obj) {
mbed_official 31:42176bc3c368 179 return (obj->spi->S & SPI_S_SPTEF_MASK) ? 1 : 0;
mbed_official 31:42176bc3c368 180 }
mbed_official 31:42176bc3c368 181
mbed_official 31:42176bc3c368 182 static inline int spi_readable(spi_t * obj) {
mbed_official 31:42176bc3c368 183 return (obj->spi->S & SPI_S_SPRF_MASK) ? 1 : 0;
mbed_official 31:42176bc3c368 184 }
mbed_official 31:42176bc3c368 185
mbed_official 31:42176bc3c368 186 int spi_master_write(spi_t *obj, int value) {
mbed_official 31:42176bc3c368 187 // wait tx buffer empty
mbed_official 31:42176bc3c368 188 while(!spi_writeable(obj));
mbed_official 31:42176bc3c368 189 obj->spi->D = (value & 0xff);
mbed_official 31:42176bc3c368 190
mbed_official 31:42176bc3c368 191 // wait rx buffer full
mbed_official 31:42176bc3c368 192 while (!spi_readable(obj));
mbed_official 31:42176bc3c368 193 return obj->spi->D & 0xff;
mbed_official 31:42176bc3c368 194 }
mbed_official 31:42176bc3c368 195
mbed_official 31:42176bc3c368 196 int spi_slave_receive(spi_t *obj) {
mbed_official 31:42176bc3c368 197 return spi_readable(obj);
mbed_official 31:42176bc3c368 198 }
mbed_official 31:42176bc3c368 199
mbed_official 31:42176bc3c368 200 int spi_slave_read(spi_t *obj) {
mbed_official 31:42176bc3c368 201 return obj->spi->D;
mbed_official 31:42176bc3c368 202 }
mbed_official 31:42176bc3c368 203
mbed_official 31:42176bc3c368 204 void spi_slave_write(spi_t *obj, int value) {
mbed_official 31:42176bc3c368 205 while (!spi_writeable(obj));
mbed_official 31:42176bc3c368 206 obj->spi->D = value;
mbed_official 31:42176bc3c368 207 }