mbed library sources
Dependents: frdm_kl05z_gpio_test
Fork of mbed-src by
targets/hal/TARGET_Freescale/TARGET_KLXX/TARGET_KL25Z/spi_api.c@323:9e901b0a5aa1, 2014-09-13 (annotated)
- Committer:
- shaoziyang
- Date:
- Sat Sep 13 14:25:46 2014 +0000
- Revision:
- 323:9e901b0a5aa1
- Parent:
- 227:7bd0639b8911
test with CLOCK_SETUP = 0
Who changed what in which revision?
User | Revision | Line number | New 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 "clk_freqs.h" |
mbed_official | 82:0b31dbcd4769 | 23 | #include "PeripheralPins.h" |
mbed_official | 82:0b31dbcd4769 | 24 | |
mbed_official | 82:0b31dbcd4769 | 25 | void spi_init(spi_t *obj, PinName mosi, PinName miso, PinName sclk, PinName ssel) { |
mbed_official | 82:0b31dbcd4769 | 26 | // determine the SPI to use |
mbed_official | 82:0b31dbcd4769 | 27 | SPIName spi_mosi = (SPIName)pinmap_peripheral(mosi, PinMap_SPI_MOSI); |
mbed_official | 82:0b31dbcd4769 | 28 | SPIName spi_miso = (SPIName)pinmap_peripheral(miso, PinMap_SPI_MISO); |
mbed_official | 82:0b31dbcd4769 | 29 | SPIName spi_sclk = (SPIName)pinmap_peripheral(sclk, PinMap_SPI_SCLK); |
mbed_official | 82:0b31dbcd4769 | 30 | SPIName spi_ssel = (SPIName)pinmap_peripheral(ssel, PinMap_SPI_SSEL); |
mbed_official | 82:0b31dbcd4769 | 31 | SPIName spi_data = (SPIName)pinmap_merge(spi_mosi, spi_miso); |
mbed_official | 82:0b31dbcd4769 | 32 | SPIName spi_cntl = (SPIName)pinmap_merge(spi_sclk, spi_ssel); |
mbed_official | 82:0b31dbcd4769 | 33 | |
mbed_official | 82:0b31dbcd4769 | 34 | obj->spi = (SPI_Type*)pinmap_merge(spi_data, spi_cntl); |
mbed_official | 227:7bd0639b8911 | 35 | MBED_ASSERT((int)obj->spi != NC); |
mbed_official | 82:0b31dbcd4769 | 36 | |
mbed_official | 82:0b31dbcd4769 | 37 | // enable power and clocking |
mbed_official | 82:0b31dbcd4769 | 38 | switch ((int)obj->spi) { |
mbed_official | 82:0b31dbcd4769 | 39 | case SPI_0: SIM->SCGC5 |= 1 << 11; SIM->SCGC4 |= 1 << 22; break; |
mbed_official | 82:0b31dbcd4769 | 40 | case SPI_1: SIM->SCGC5 |= 1 << 13; SIM->SCGC4 |= 1 << 23; break; |
mbed_official | 82:0b31dbcd4769 | 41 | } |
mbed_official | 82:0b31dbcd4769 | 42 | |
mbed_official | 82:0b31dbcd4769 | 43 | // set default format and frequency |
mbed_official | 82:0b31dbcd4769 | 44 | if (ssel == NC) { |
mbed_official | 82:0b31dbcd4769 | 45 | spi_format(obj, 8, 0, 0); // 8 bits, mode 0, master |
mbed_official | 82:0b31dbcd4769 | 46 | } else { |
mbed_official | 82:0b31dbcd4769 | 47 | spi_format(obj, 8, 0, 1); // 8 bits, mode 0, slave |
mbed_official | 82:0b31dbcd4769 | 48 | } |
mbed_official | 82:0b31dbcd4769 | 49 | spi_frequency(obj, 1000000); |
mbed_official | 82:0b31dbcd4769 | 50 | |
mbed_official | 82:0b31dbcd4769 | 51 | // enable SPI |
mbed_official | 82:0b31dbcd4769 | 52 | obj->spi->C1 |= SPI_C1_SPE_MASK; |
mbed_official | 82:0b31dbcd4769 | 53 | |
mbed_official | 82:0b31dbcd4769 | 54 | // pin out the spi pins |
mbed_official | 82:0b31dbcd4769 | 55 | pinmap_pinout(mosi, PinMap_SPI_MOSI); |
mbed_official | 82:0b31dbcd4769 | 56 | pinmap_pinout(miso, PinMap_SPI_MISO); |
mbed_official | 82:0b31dbcd4769 | 57 | pinmap_pinout(sclk, PinMap_SPI_SCLK); |
mbed_official | 82:0b31dbcd4769 | 58 | if (ssel != NC) { |
mbed_official | 82:0b31dbcd4769 | 59 | pinmap_pinout(ssel, PinMap_SPI_SSEL); |
mbed_official | 82:0b31dbcd4769 | 60 | } |
mbed_official | 82:0b31dbcd4769 | 61 | } |
mbed_official | 82:0b31dbcd4769 | 62 | |
mbed_official | 82:0b31dbcd4769 | 63 | void spi_free(spi_t *obj) { |
mbed_official | 82:0b31dbcd4769 | 64 | // [TODO] |
mbed_official | 82:0b31dbcd4769 | 65 | } |
mbed_official | 82:0b31dbcd4769 | 66 | void spi_format(spi_t *obj, int bits, int mode, int slave) { |
mbed_official | 227:7bd0639b8911 | 67 | MBED_ASSERT(bits == 8); |
mbed_official | 227:7bd0639b8911 | 68 | MBED_ASSERT((mode >= 0) && (mode <= 3)); |
mbed_official | 82:0b31dbcd4769 | 69 | |
mbed_official | 82:0b31dbcd4769 | 70 | uint8_t polarity = (mode & 0x2) ? 1 : 0; |
mbed_official | 82:0b31dbcd4769 | 71 | uint8_t phase = (mode & 0x1) ? 1 : 0; |
mbed_official | 82:0b31dbcd4769 | 72 | uint8_t c1_data = ((!slave) << 4) | (polarity << 3) | (phase << 2); |
mbed_official | 82:0b31dbcd4769 | 73 | |
mbed_official | 82:0b31dbcd4769 | 74 | // clear MSTR, CPOL and CPHA bits |
mbed_official | 82:0b31dbcd4769 | 75 | obj->spi->C1 &= ~(0x7 << 2); |
mbed_official | 82:0b31dbcd4769 | 76 | |
mbed_official | 82:0b31dbcd4769 | 77 | // write new value |
mbed_official | 82:0b31dbcd4769 | 78 | obj->spi->C1 |= c1_data; |
mbed_official | 82:0b31dbcd4769 | 79 | } |
mbed_official | 82:0b31dbcd4769 | 80 | |
mbed_official | 82:0b31dbcd4769 | 81 | void spi_frequency(spi_t *obj, int hz) { |
mbed_official | 82:0b31dbcd4769 | 82 | uint32_t error = 0; |
mbed_official | 82:0b31dbcd4769 | 83 | uint32_t p_error = 0xffffffff; |
mbed_official | 82:0b31dbcd4769 | 84 | uint32_t ref = 0; |
mbed_official | 82:0b31dbcd4769 | 85 | uint8_t spr = 0; |
mbed_official | 82:0b31dbcd4769 | 86 | uint8_t ref_spr = 0; |
mbed_official | 82:0b31dbcd4769 | 87 | uint8_t ref_prescaler = 0; |
mbed_official | 82:0b31dbcd4769 | 88 | |
mbed_official | 82:0b31dbcd4769 | 89 | // bus clk |
mbed_official | 82:0b31dbcd4769 | 90 | uint32_t PCLK = bus_frequency(); |
mbed_official | 82:0b31dbcd4769 | 91 | uint8_t prescaler = 1; |
mbed_official | 82:0b31dbcd4769 | 92 | uint8_t divisor = 2; |
mbed_official | 82:0b31dbcd4769 | 93 | |
mbed_official | 82:0b31dbcd4769 | 94 | for (prescaler = 1; prescaler <= 8; prescaler++) { |
mbed_official | 82:0b31dbcd4769 | 95 | divisor = 2; |
mbed_official | 82:0b31dbcd4769 | 96 | for (spr = 0; spr <= 8; spr++, divisor *= 2) { |
mbed_official | 82:0b31dbcd4769 | 97 | ref = PCLK / (prescaler*divisor); |
mbed_official | 82:0b31dbcd4769 | 98 | if (ref > (uint32_t)hz) |
mbed_official | 82:0b31dbcd4769 | 99 | continue; |
mbed_official | 82:0b31dbcd4769 | 100 | error = hz - ref; |
mbed_official | 82:0b31dbcd4769 | 101 | if (error < p_error) { |
mbed_official | 82:0b31dbcd4769 | 102 | ref_spr = spr; |
mbed_official | 82:0b31dbcd4769 | 103 | ref_prescaler = prescaler - 1; |
mbed_official | 82:0b31dbcd4769 | 104 | p_error = error; |
mbed_official | 82:0b31dbcd4769 | 105 | } |
mbed_official | 82:0b31dbcd4769 | 106 | } |
mbed_official | 82:0b31dbcd4769 | 107 | } |
mbed_official | 82:0b31dbcd4769 | 108 | |
mbed_official | 82:0b31dbcd4769 | 109 | // set SPPR and SPR |
mbed_official | 82:0b31dbcd4769 | 110 | obj->spi->BR = ((ref_prescaler & 0x7) << 4) | (ref_spr & 0xf); |
mbed_official | 82:0b31dbcd4769 | 111 | } |
mbed_official | 82:0b31dbcd4769 | 112 | |
mbed_official | 82:0b31dbcd4769 | 113 | static inline int spi_writeable(spi_t * obj) { |
mbed_official | 82:0b31dbcd4769 | 114 | return (obj->spi->S & SPI_S_SPTEF_MASK) ? 1 : 0; |
mbed_official | 82:0b31dbcd4769 | 115 | } |
mbed_official | 82:0b31dbcd4769 | 116 | |
mbed_official | 82:0b31dbcd4769 | 117 | static inline int spi_readable(spi_t * obj) { |
mbed_official | 82:0b31dbcd4769 | 118 | return (obj->spi->S & SPI_S_SPRF_MASK) ? 1 : 0; |
mbed_official | 82:0b31dbcd4769 | 119 | } |
mbed_official | 82:0b31dbcd4769 | 120 | |
mbed_official | 82:0b31dbcd4769 | 121 | int spi_master_write(spi_t *obj, int value) { |
mbed_official | 82:0b31dbcd4769 | 122 | // wait tx buffer empty |
mbed_official | 82:0b31dbcd4769 | 123 | while(!spi_writeable(obj)); |
mbed_official | 82:0b31dbcd4769 | 124 | obj->spi->D = (value & 0xff); |
mbed_official | 82:0b31dbcd4769 | 125 | |
mbed_official | 82:0b31dbcd4769 | 126 | // wait rx buffer full |
mbed_official | 82:0b31dbcd4769 | 127 | while (!spi_readable(obj)); |
mbed_official | 82:0b31dbcd4769 | 128 | return obj->spi->D & 0xff; |
mbed_official | 82:0b31dbcd4769 | 129 | } |
mbed_official | 82:0b31dbcd4769 | 130 | |
mbed_official | 82:0b31dbcd4769 | 131 | int spi_slave_receive(spi_t *obj) { |
mbed_official | 82:0b31dbcd4769 | 132 | return spi_readable(obj); |
mbed_official | 82:0b31dbcd4769 | 133 | } |
mbed_official | 82:0b31dbcd4769 | 134 | |
mbed_official | 82:0b31dbcd4769 | 135 | int spi_slave_read(spi_t *obj) { |
mbed_official | 82:0b31dbcd4769 | 136 | return obj->spi->D; |
mbed_official | 82:0b31dbcd4769 | 137 | } |
mbed_official | 82:0b31dbcd4769 | 138 | |
mbed_official | 82:0b31dbcd4769 | 139 | void spi_slave_write(spi_t *obj, int value) { |
mbed_official | 82:0b31dbcd4769 | 140 | while (!spi_writeable(obj)); |
mbed_official | 82:0b31dbcd4769 | 141 | obj->spi->D = value; |
mbed_official | 82:0b31dbcd4769 | 142 | } |