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Last commit 20 Feb 2019 by mbed official

targets/hal/TARGET_Freescale/TARGET_KL25Z/spi_api.c@13:0645d8841f51, 2013-08-05 (annotated)

Committer:
bogdanm
Date:
Mon Aug 05 14:12:34 2013 +0300
Revision:
13:0645d8841f51
Child:
15:4892fe388435
Update mbed sources to revision 64

Who changed what in which revision?

UserRevisionLine numberNew contents of line
bogdanm 13:0645d8841f51 1 /* mbed Microcontroller Library
bogdanm 13:0645d8841f51 2 * Copyright (c) 2006-2013 ARM Limited
bogdanm 13:0645d8841f51 3 *
bogdanm 13:0645d8841f51 4 * Licensed under the Apache License, Version 2.0 (the "License");
bogdanm 13:0645d8841f51 5 * you may not use this file except in compliance with the License.
bogdanm 13:0645d8841f51 6 * You may obtain a copy of the License at
bogdanm 13:0645d8841f51 7 *
bogdanm 13:0645d8841f51 8 * http://www.apache.org/licenses/LICENSE-2.0
bogdanm 13:0645d8841f51 9 *
bogdanm 13:0645d8841f51 10 * Unless required by applicable law or agreed to in writing, software
bogdanm 13:0645d8841f51 11 * distributed under the License is distributed on an "AS IS" BASIS,
bogdanm 13:0645d8841f51 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
bogdanm 13:0645d8841f51 13 * See the License for the specific language governing permissions and
bogdanm 13:0645d8841f51 14 * limitations under the License.
bogdanm 13:0645d8841f51 15 */
bogdanm 13:0645d8841f51 16 #include "spi_api.h"
bogdanm 13:0645d8841f51 17
bogdanm 13:0645d8841f51 18 #include <math.h>
bogdanm 13:0645d8841f51 19
bogdanm 13:0645d8841f51 20 #include "cmsis.h"
bogdanm 13:0645d8841f51 21 #include "pinmap.h"
bogdanm 13:0645d8841f51 22 #include "error.h"
bogdanm 13:0645d8841f51 23
bogdanm 13:0645d8841f51 24 static const PinMap PinMap_SPI_SCLK[] = {
bogdanm 13:0645d8841f51 25 {PTA15, SPI_0, 2},
bogdanm 13:0645d8841f51 26 {PTB11, SPI_1, 2},
bogdanm 13:0645d8841f51 27 {PTC5, SPI_0, 2},
bogdanm 13:0645d8841f51 28 {PTD1, SPI_0, 2},
bogdanm 13:0645d8841f51 29 {PTD5, SPI_1, 2},
bogdanm 13:0645d8841f51 30 {PTE2, SPI_1, 2},
bogdanm 13:0645d8841f51 31 {NC , NC , 0}
bogdanm 13:0645d8841f51 32 };
bogdanm 13:0645d8841f51 33
bogdanm 13:0645d8841f51 34 static const PinMap PinMap_SPI_MOSI[] = {
bogdanm 13:0645d8841f51 35 {PTA16, SPI_0, 2},
bogdanm 13:0645d8841f51 36 {PTA17, SPI_0, 5},
bogdanm 13:0645d8841f51 37 {PTB16, SPI_1, 2},
bogdanm 13:0645d8841f51 38 {PTB17, SPI_1, 5},
bogdanm 13:0645d8841f51 39 {PTC6, SPI_0, 2},
bogdanm 13:0645d8841f51 40 {PTC7, SPI_0, 5},
bogdanm 13:0645d8841f51 41 {PTD2, SPI_0, 2},
bogdanm 13:0645d8841f51 42 {PTD3, SPI_0, 5},
bogdanm 13:0645d8841f51 43 {PTD6, SPI_1, 2},
bogdanm 13:0645d8841f51 44 {PTD7, SPI_1, 5},
bogdanm 13:0645d8841f51 45 {PTE1, SPI_1, 2},
bogdanm 13:0645d8841f51 46 {PTE3, SPI_1, 5},
bogdanm 13:0645d8841f51 47 {NC , NC , 0}
bogdanm 13:0645d8841f51 48 };
bogdanm 13:0645d8841f51 49
bogdanm 13:0645d8841f51 50 static const PinMap PinMap_SPI_MISO[] = {
bogdanm 13:0645d8841f51 51 {PTA16, SPI_0, 5},
bogdanm 13:0645d8841f51 52 {PTA17, SPI_0, 2},
bogdanm 13:0645d8841f51 53 {PTB16, SPI_1, 5},
bogdanm 13:0645d8841f51 54 {PTB17, SPI_1, 2},
bogdanm 13:0645d8841f51 55 {PTC6, SPI_0, 5},
bogdanm 13:0645d8841f51 56 {PTC7, SPI_0, 2},
bogdanm 13:0645d8841f51 57 {PTD2, SPI_0, 5},
bogdanm 13:0645d8841f51 58 {PTD3, SPI_0, 2},
bogdanm 13:0645d8841f51 59 {PTD6, SPI_1, 5},
bogdanm 13:0645d8841f51 60 {PTD7, SPI_1, 2},
bogdanm 13:0645d8841f51 61 {PTE1, SPI_1, 5},
bogdanm 13:0645d8841f51 62 {PTE3, SPI_1, 2},
bogdanm 13:0645d8841f51 63 {NC , NC , 0}
bogdanm 13:0645d8841f51 64 };
bogdanm 13:0645d8841f51 65
bogdanm 13:0645d8841f51 66 static const PinMap PinMap_SPI_SSEL[] = {
bogdanm 13:0645d8841f51 67 {PTA14, SPI_0, 2},
bogdanm 13:0645d8841f51 68 {PTB10, SPI_1, 2},
bogdanm 13:0645d8841f51 69 {PTC4, SPI_0, 2},
bogdanm 13:0645d8841f51 70 {PTD0, SPI_0, 2},
bogdanm 13:0645d8841f51 71 {PTD4, SPI_1, 2},
bogdanm 13:0645d8841f51 72 {PTE4, SPI_1, 2},
bogdanm 13:0645d8841f51 73 {NC , NC , 0}
bogdanm 13:0645d8841f51 74 };
bogdanm 13:0645d8841f51 75
bogdanm 13:0645d8841f51 76 void spi_init(spi_t *obj, PinName mosi, PinName miso, PinName sclk, PinName ssel) {
bogdanm 13:0645d8841f51 77 // determine the SPI to use
bogdanm 13:0645d8841f51 78 SPIName spi_mosi = (SPIName)pinmap_peripheral(mosi, PinMap_SPI_MOSI);
bogdanm 13:0645d8841f51 79 SPIName spi_miso = (SPIName)pinmap_peripheral(miso, PinMap_SPI_MISO);
bogdanm 13:0645d8841f51 80 SPIName spi_sclk = (SPIName)pinmap_peripheral(sclk, PinMap_SPI_SCLK);
bogdanm 13:0645d8841f51 81 SPIName spi_ssel = (SPIName)pinmap_peripheral(ssel, PinMap_SPI_SSEL);
bogdanm 13:0645d8841f51 82 SPIName spi_data = (SPIName)pinmap_merge(spi_mosi, spi_miso);
bogdanm 13:0645d8841f51 83 SPIName spi_cntl = (SPIName)pinmap_merge(spi_sclk, spi_ssel);
bogdanm 13:0645d8841f51 84
bogdanm 13:0645d8841f51 85 obj->spi = (SPI_Type*)pinmap_merge(spi_data, spi_cntl);
bogdanm 13:0645d8841f51 86 if ((int)obj->spi == NC) {
bogdanm 13:0645d8841f51 87 error("SPI pinout mapping failed");
bogdanm 13:0645d8841f51 88 }
bogdanm 13:0645d8841f51 89
bogdanm 13:0645d8841f51 90 // enable power and clocking
bogdanm 13:0645d8841f51 91 switch ((int)obj->spi) {
bogdanm 13:0645d8841f51 92 case SPI_0: SIM->SCGC5 |= 1 << 11; SIM->SCGC4 |= 1 << 22; break;
bogdanm 13:0645d8841f51 93 case SPI_1: SIM->SCGC5 |= 1 << 13; SIM->SCGC4 |= 1 << 23; break;
bogdanm 13:0645d8841f51 94 }
bogdanm 13:0645d8841f51 95
bogdanm 13:0645d8841f51 96 // set default format and frequency
bogdanm 13:0645d8841f51 97 if (ssel == NC) {
bogdanm 13:0645d8841f51 98 spi_format(obj, 8, 0, 0); // 8 bits, mode 0, master
bogdanm 13:0645d8841f51 99 } else {
bogdanm 13:0645d8841f51 100 spi_format(obj, 8, 0, 1); // 8 bits, mode 0, slave
bogdanm 13:0645d8841f51 101 }
bogdanm 13:0645d8841f51 102 spi_frequency(obj, 1000000);
bogdanm 13:0645d8841f51 103
bogdanm 13:0645d8841f51 104 // enable SPI
bogdanm 13:0645d8841f51 105 obj->spi->C1 |= SPI_C1_SPE_MASK;
bogdanm 13:0645d8841f51 106
bogdanm 13:0645d8841f51 107 // pin out the spi pins
bogdanm 13:0645d8841f51 108 pinmap_pinout(mosi, PinMap_SPI_MOSI);
bogdanm 13:0645d8841f51 109 pinmap_pinout(miso, PinMap_SPI_MISO);
bogdanm 13:0645d8841f51 110 pinmap_pinout(sclk, PinMap_SPI_SCLK);
bogdanm 13:0645d8841f51 111 if (ssel != NC) {
bogdanm 13:0645d8841f51 112 pinmap_pinout(ssel, PinMap_SPI_SSEL);
bogdanm 13:0645d8841f51 113 }
bogdanm 13:0645d8841f51 114 }
bogdanm 13:0645d8841f51 115
bogdanm 13:0645d8841f51 116 void spi_free(spi_t *obj) {
bogdanm 13:0645d8841f51 117 // [TODO]
bogdanm 13:0645d8841f51 118 }
bogdanm 13:0645d8841f51 119 void spi_format(spi_t *obj, int bits, int mode, int slave) {
bogdanm 13:0645d8841f51 120 if (bits != 8) {
bogdanm 13:0645d8841f51 121 error("Only 8bits SPI supported");
bogdanm 13:0645d8841f51 122 }
bogdanm 13:0645d8841f51 123
bogdanm 13:0645d8841f51 124 if ((mode < 0) || (mode > 3)) {
bogdanm 13:0645d8841f51 125 error("SPI mode unsupported");
bogdanm 13:0645d8841f51 126 }
bogdanm 13:0645d8841f51 127
bogdanm 13:0645d8841f51 128 uint8_t polarity = (mode & 0x2) ? 1 : 0;
bogdanm 13:0645d8841f51 129 uint8_t phase = (mode & 0x1) ? 1 : 0;
bogdanm 13:0645d8841f51 130 uint8_t c1_data = ((!slave) << 4) | (polarity << 3) | (phase << 2);
bogdanm 13:0645d8841f51 131
bogdanm 13:0645d8841f51 132 // clear MSTR, CPOL and CPHA bits
bogdanm 13:0645d8841f51 133 obj->spi->C1 &= ~(0x7 << 2);
bogdanm 13:0645d8841f51 134
bogdanm 13:0645d8841f51 135 // write new value
bogdanm 13:0645d8841f51 136 obj->spi->C1 |= c1_data;
bogdanm 13:0645d8841f51 137 }
bogdanm 13:0645d8841f51 138
bogdanm 13:0645d8841f51 139 void spi_frequency(spi_t *obj, int hz) {
bogdanm 13:0645d8841f51 140 uint32_t error = 0;
bogdanm 13:0645d8841f51 141 uint32_t p_error = 0xffffffff;
bogdanm 13:0645d8841f51 142 uint32_t ref = 0;
bogdanm 13:0645d8841f51 143 uint8_t spr = 0;
bogdanm 13:0645d8841f51 144 uint8_t ref_spr = 0;
bogdanm 13:0645d8841f51 145 uint8_t ref_prescaler = 0;
bogdanm 13:0645d8841f51 146
bogdanm 13:0645d8841f51 147 // bus clk
bogdanm 13:0645d8841f51 148 uint32_t PCLK = 48000000u;
bogdanm 13:0645d8841f51 149 uint8_t prescaler = 1;
bogdanm 13:0645d8841f51 150 uint8_t divisor = 2;
bogdanm 13:0645d8841f51 151
bogdanm 13:0645d8841f51 152 for (prescaler = 1; prescaler <= 8; prescaler++) {
bogdanm 13:0645d8841f51 153 divisor = 2;
bogdanm 13:0645d8841f51 154 for (spr = 0; spr <= 8; spr++, divisor *= 2) {
bogdanm 13:0645d8841f51 155 ref = PCLK / (prescaler*divisor);
bogdanm 13:0645d8841f51 156 if (ref > hz)
bogdanm 13:0645d8841f51 157 continue;
bogdanm 13:0645d8841f51 158 error = hz - ref;
bogdanm 13:0645d8841f51 159 if (error < p_error) {
bogdanm 13:0645d8841f51 160 ref_spr = spr;
bogdanm 13:0645d8841f51 161 ref_prescaler = prescaler - 1;
bogdanm 13:0645d8841f51 162 p_error = error;
bogdanm 13:0645d8841f51 163 }
bogdanm 13:0645d8841f51 164 }
bogdanm 13:0645d8841f51 165 }
bogdanm 13:0645d8841f51 166
bogdanm 13:0645d8841f51 167 // set SPPR and SPR
bogdanm 13:0645d8841f51 168 obj->spi->BR = ((ref_prescaler & 0x7) << 4) | (ref_spr & 0xf);
bogdanm 13:0645d8841f51 169 }
bogdanm 13:0645d8841f51 170
bogdanm 13:0645d8841f51 171 static inline int spi_writeable(spi_t * obj) {
bogdanm 13:0645d8841f51 172 return (obj->spi->S & SPI_S_SPTEF_MASK) ? 1 : 0;
bogdanm 13:0645d8841f51 173 }
bogdanm 13:0645d8841f51 174
bogdanm 13:0645d8841f51 175 static inline int spi_readable(spi_t * obj) {
bogdanm 13:0645d8841f51 176 return (obj->spi->S & SPI_S_SPRF_MASK) ? 1 : 0;
bogdanm 13:0645d8841f51 177 }
bogdanm 13:0645d8841f51 178
bogdanm 13:0645d8841f51 179 int spi_master_write(spi_t *obj, int value) {
bogdanm 13:0645d8841f51 180 // wait tx buffer empty
bogdanm 13:0645d8841f51 181 while(!spi_writeable(obj));
bogdanm 13:0645d8841f51 182 obj->spi->D = (value & 0xff);
bogdanm 13:0645d8841f51 183
bogdanm 13:0645d8841f51 184 // wait rx buffer full
bogdanm 13:0645d8841f51 185 while (!spi_readable(obj));
bogdanm 13:0645d8841f51 186 return obj->spi->D & 0xff;
bogdanm 13:0645d8841f51 187 }
bogdanm 13:0645d8841f51 188
bogdanm 13:0645d8841f51 189 int spi_slave_receive(spi_t *obj) {
bogdanm 13:0645d8841f51 190 return spi_readable(obj);
bogdanm 13:0645d8841f51 191 }
bogdanm 13:0645d8841f51 192
bogdanm 13:0645d8841f51 193 int spi_slave_read(spi_t *obj) {
bogdanm 13:0645d8841f51 194 return obj->spi->D;
bogdanm 13:0645d8841f51 195 }
bogdanm 13:0645d8841f51 196
bogdanm 13:0645d8841f51 197 void spi_slave_write(spi_t *obj, int value) {
bogdanm 13:0645d8841f51 198 while (!spi_writeable(obj));
bogdanm 13:0645d8841f51 199 obj->spi->D = value;
bogdanm 13:0645d8841f51 200 }