added prescaler for 16 bit pwm in LPC1347 target
Fork of mbed-dev by
targets/hal/TARGET_Freescale/TARGET_KLXX/TARGET_KL25Z/spi_api.c@0:9b334a45a8ff, 2015-10-01 (annotated)
- Committer:
- bogdanm
- Date:
- Thu Oct 01 15:25:22 2015 +0300
- Revision:
- 0:9b334a45a8ff
- Child:
- 144:ef7eb2e8f9f7
Initial commit on mbed-dev
Replaces mbed-src (now inactive)
Who changed what in which revision?
User | Revision | Line number | New contents of line |
---|---|---|---|
bogdanm | 0:9b334a45a8ff | 1 | /* mbed Microcontroller Library |
bogdanm | 0:9b334a45a8ff | 2 | * Copyright (c) 2006-2013 ARM Limited |
bogdanm | 0:9b334a45a8ff | 3 | * |
bogdanm | 0:9b334a45a8ff | 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
bogdanm | 0:9b334a45a8ff | 5 | * you may not use this file except in compliance with the License. |
bogdanm | 0:9b334a45a8ff | 6 | * You may obtain a copy of the License at |
bogdanm | 0:9b334a45a8ff | 7 | * |
bogdanm | 0:9b334a45a8ff | 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
bogdanm | 0:9b334a45a8ff | 9 | * |
bogdanm | 0:9b334a45a8ff | 10 | * Unless required by applicable law or agreed to in writing, software |
bogdanm | 0:9b334a45a8ff | 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
bogdanm | 0:9b334a45a8ff | 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
bogdanm | 0:9b334a45a8ff | 13 | * See the License for the specific language governing permissions and |
bogdanm | 0:9b334a45a8ff | 14 | * limitations under the License. |
bogdanm | 0:9b334a45a8ff | 15 | */ |
bogdanm | 0:9b334a45a8ff | 16 | #include "spi_api.h" |
bogdanm | 0:9b334a45a8ff | 17 | |
bogdanm | 0:9b334a45a8ff | 18 | #include <math.h> |
bogdanm | 0:9b334a45a8ff | 19 | |
bogdanm | 0:9b334a45a8ff | 20 | #include "cmsis.h" |
bogdanm | 0:9b334a45a8ff | 21 | #include "pinmap.h" |
bogdanm | 0:9b334a45a8ff | 22 | #include "clk_freqs.h" |
bogdanm | 0:9b334a45a8ff | 23 | #include "PeripheralPins.h" |
bogdanm | 0:9b334a45a8ff | 24 | |
bogdanm | 0:9b334a45a8ff | 25 | void spi_init(spi_t *obj, PinName mosi, PinName miso, PinName sclk, PinName ssel) { |
bogdanm | 0:9b334a45a8ff | 26 | // determine the SPI to use |
bogdanm | 0:9b334a45a8ff | 27 | SPIName spi_mosi = (SPIName)pinmap_peripheral(mosi, PinMap_SPI_MOSI); |
bogdanm | 0:9b334a45a8ff | 28 | SPIName spi_miso = (SPIName)pinmap_peripheral(miso, PinMap_SPI_MISO); |
bogdanm | 0:9b334a45a8ff | 29 | SPIName spi_sclk = (SPIName)pinmap_peripheral(sclk, PinMap_SPI_SCLK); |
bogdanm | 0:9b334a45a8ff | 30 | SPIName spi_ssel = (SPIName)pinmap_peripheral(ssel, PinMap_SPI_SSEL); |
bogdanm | 0:9b334a45a8ff | 31 | SPIName spi_data = (SPIName)pinmap_merge(spi_mosi, spi_miso); |
bogdanm | 0:9b334a45a8ff | 32 | SPIName spi_cntl = (SPIName)pinmap_merge(spi_sclk, spi_ssel); |
bogdanm | 0:9b334a45a8ff | 33 | |
bogdanm | 0:9b334a45a8ff | 34 | obj->spi = (SPI_Type*)pinmap_merge(spi_data, spi_cntl); |
bogdanm | 0:9b334a45a8ff | 35 | MBED_ASSERT((int)obj->spi != NC); |
bogdanm | 0:9b334a45a8ff | 36 | |
bogdanm | 0:9b334a45a8ff | 37 | // enable power and clocking |
bogdanm | 0:9b334a45a8ff | 38 | switch ((int)obj->spi) { |
bogdanm | 0:9b334a45a8ff | 39 | case SPI_0: SIM->SCGC5 |= 1 << 11; SIM->SCGC4 |= 1 << 22; break; |
bogdanm | 0:9b334a45a8ff | 40 | case SPI_1: SIM->SCGC5 |= 1 << 13; SIM->SCGC4 |= 1 << 23; break; |
bogdanm | 0:9b334a45a8ff | 41 | } |
bogdanm | 0:9b334a45a8ff | 42 | |
bogdanm | 0:9b334a45a8ff | 43 | // enable SPI |
bogdanm | 0:9b334a45a8ff | 44 | obj->spi->C1 |= SPI_C1_SPE_MASK; |
bogdanm | 0:9b334a45a8ff | 45 | |
bogdanm | 0:9b334a45a8ff | 46 | // pin out the spi pins |
bogdanm | 0:9b334a45a8ff | 47 | pinmap_pinout(mosi, PinMap_SPI_MOSI); |
bogdanm | 0:9b334a45a8ff | 48 | pinmap_pinout(miso, PinMap_SPI_MISO); |
bogdanm | 0:9b334a45a8ff | 49 | pinmap_pinout(sclk, PinMap_SPI_SCLK); |
bogdanm | 0:9b334a45a8ff | 50 | if (ssel != NC) { |
bogdanm | 0:9b334a45a8ff | 51 | pinmap_pinout(ssel, PinMap_SPI_SSEL); |
bogdanm | 0:9b334a45a8ff | 52 | } |
bogdanm | 0:9b334a45a8ff | 53 | } |
bogdanm | 0:9b334a45a8ff | 54 | |
bogdanm | 0:9b334a45a8ff | 55 | void spi_free(spi_t *obj) { |
bogdanm | 0:9b334a45a8ff | 56 | // [TODO] |
bogdanm | 0:9b334a45a8ff | 57 | } |
bogdanm | 0:9b334a45a8ff | 58 | void spi_format(spi_t *obj, int bits, int mode, int slave) { |
bogdanm | 0:9b334a45a8ff | 59 | MBED_ASSERT(bits == 8); |
bogdanm | 0:9b334a45a8ff | 60 | MBED_ASSERT((mode >= 0) && (mode <= 3)); |
bogdanm | 0:9b334a45a8ff | 61 | |
bogdanm | 0:9b334a45a8ff | 62 | uint8_t polarity = (mode & 0x2) ? 1 : 0; |
bogdanm | 0:9b334a45a8ff | 63 | uint8_t phase = (mode & 0x1) ? 1 : 0; |
bogdanm | 0:9b334a45a8ff | 64 | uint8_t c1_data = ((!slave) << 4) | (polarity << 3) | (phase << 2); |
bogdanm | 0:9b334a45a8ff | 65 | |
bogdanm | 0:9b334a45a8ff | 66 | // clear MSTR, CPOL and CPHA bits |
bogdanm | 0:9b334a45a8ff | 67 | obj->spi->C1 &= ~(0x7 << 2); |
bogdanm | 0:9b334a45a8ff | 68 | |
bogdanm | 0:9b334a45a8ff | 69 | // write new value |
bogdanm | 0:9b334a45a8ff | 70 | obj->spi->C1 |= c1_data; |
bogdanm | 0:9b334a45a8ff | 71 | } |
bogdanm | 0:9b334a45a8ff | 72 | |
bogdanm | 0:9b334a45a8ff | 73 | void spi_frequency(spi_t *obj, int hz) { |
bogdanm | 0:9b334a45a8ff | 74 | uint32_t error = 0; |
bogdanm | 0:9b334a45a8ff | 75 | uint32_t p_error = 0xffffffff; |
bogdanm | 0:9b334a45a8ff | 76 | uint32_t ref = 0; |
bogdanm | 0:9b334a45a8ff | 77 | uint8_t spr = 0; |
bogdanm | 0:9b334a45a8ff | 78 | uint8_t ref_spr = 0; |
bogdanm | 0:9b334a45a8ff | 79 | uint8_t ref_prescaler = 0; |
bogdanm | 0:9b334a45a8ff | 80 | |
bogdanm | 0:9b334a45a8ff | 81 | // bus clk |
bogdanm | 0:9b334a45a8ff | 82 | uint32_t PCLK = bus_frequency(); |
bogdanm | 0:9b334a45a8ff | 83 | uint8_t prescaler = 1; |
bogdanm | 0:9b334a45a8ff | 84 | uint8_t divisor = 2; |
bogdanm | 0:9b334a45a8ff | 85 | |
bogdanm | 0:9b334a45a8ff | 86 | for (prescaler = 1; prescaler <= 8; prescaler++) { |
bogdanm | 0:9b334a45a8ff | 87 | divisor = 2; |
bogdanm | 0:9b334a45a8ff | 88 | for (spr = 0; spr <= 8; spr++, divisor *= 2) { |
bogdanm | 0:9b334a45a8ff | 89 | ref = PCLK / (prescaler*divisor); |
bogdanm | 0:9b334a45a8ff | 90 | if (ref > (uint32_t)hz) |
bogdanm | 0:9b334a45a8ff | 91 | continue; |
bogdanm | 0:9b334a45a8ff | 92 | error = hz - ref; |
bogdanm | 0:9b334a45a8ff | 93 | if (error < p_error) { |
bogdanm | 0:9b334a45a8ff | 94 | ref_spr = spr; |
bogdanm | 0:9b334a45a8ff | 95 | ref_prescaler = prescaler - 1; |
bogdanm | 0:9b334a45a8ff | 96 | p_error = error; |
bogdanm | 0:9b334a45a8ff | 97 | } |
bogdanm | 0:9b334a45a8ff | 98 | } |
bogdanm | 0:9b334a45a8ff | 99 | } |
bogdanm | 0:9b334a45a8ff | 100 | |
bogdanm | 0:9b334a45a8ff | 101 | // set SPPR and SPR |
bogdanm | 0:9b334a45a8ff | 102 | obj->spi->BR = ((ref_prescaler & 0x7) << 4) | (ref_spr & 0xf); |
bogdanm | 0:9b334a45a8ff | 103 | } |
bogdanm | 0:9b334a45a8ff | 104 | |
bogdanm | 0:9b334a45a8ff | 105 | static inline int spi_writeable(spi_t * obj) { |
bogdanm | 0:9b334a45a8ff | 106 | return (obj->spi->S & SPI_S_SPTEF_MASK) ? 1 : 0; |
bogdanm | 0:9b334a45a8ff | 107 | } |
bogdanm | 0:9b334a45a8ff | 108 | |
bogdanm | 0:9b334a45a8ff | 109 | static inline int spi_readable(spi_t * obj) { |
bogdanm | 0:9b334a45a8ff | 110 | return (obj->spi->S & SPI_S_SPRF_MASK) ? 1 : 0; |
bogdanm | 0:9b334a45a8ff | 111 | } |
bogdanm | 0:9b334a45a8ff | 112 | |
bogdanm | 0:9b334a45a8ff | 113 | int spi_master_write(spi_t *obj, int value) { |
bogdanm | 0:9b334a45a8ff | 114 | // wait tx buffer empty |
bogdanm | 0:9b334a45a8ff | 115 | while(!spi_writeable(obj)); |
bogdanm | 0:9b334a45a8ff | 116 | obj->spi->D = (value & 0xff); |
bogdanm | 0:9b334a45a8ff | 117 | |
bogdanm | 0:9b334a45a8ff | 118 | // wait rx buffer full |
bogdanm | 0:9b334a45a8ff | 119 | while (!spi_readable(obj)); |
bogdanm | 0:9b334a45a8ff | 120 | return obj->spi->D & 0xff; |
bogdanm | 0:9b334a45a8ff | 121 | } |
bogdanm | 0:9b334a45a8ff | 122 | |
bogdanm | 0:9b334a45a8ff | 123 | int spi_slave_receive(spi_t *obj) { |
bogdanm | 0:9b334a45a8ff | 124 | return spi_readable(obj); |
bogdanm | 0:9b334a45a8ff | 125 | } |
bogdanm | 0:9b334a45a8ff | 126 | |
bogdanm | 0:9b334a45a8ff | 127 | int spi_slave_read(spi_t *obj) { |
bogdanm | 0:9b334a45a8ff | 128 | return obj->spi->D; |
bogdanm | 0:9b334a45a8ff | 129 | } |
bogdanm | 0:9b334a45a8ff | 130 | |
bogdanm | 0:9b334a45a8ff | 131 | void spi_slave_write(spi_t *obj, int value) { |
bogdanm | 0:9b334a45a8ff | 132 | while (!spi_writeable(obj)); |
bogdanm | 0:9b334a45a8ff | 133 | obj->spi->D = value; |
bogdanm | 0:9b334a45a8ff | 134 | } |