mbed library sources modified for open wear
Dependents: openwear-lifelogger-example
Fork of mbed-src by
targets/hal/TARGET_NXP/TARGET_LPC23XX/spi_api.c@310:6188e0254baa, 2014-09-16 (annotated)
- Committer:
- janekm
- Date:
- Tue Sep 16 22:42:01 2014 +0000
- Revision:
- 310:6188e0254baa
- Parent:
- 286:31249416b6f9
N/A
Who changed what in which revision?
User | Revision | Line number | New contents of line |
---|---|---|---|
emilmont | 10:3bc89ef62ce7 | 1 | /* mbed Microcontroller Library |
emilmont | 10:3bc89ef62ce7 | 2 | * Copyright (c) 2006-2013 ARM Limited |
emilmont | 10:3bc89ef62ce7 | 3 | * |
emilmont | 10:3bc89ef62ce7 | 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
emilmont | 10:3bc89ef62ce7 | 5 | * you may not use this file except in compliance with the License. |
emilmont | 10:3bc89ef62ce7 | 6 | * You may obtain a copy of the License at |
emilmont | 10:3bc89ef62ce7 | 7 | * |
emilmont | 10:3bc89ef62ce7 | 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
emilmont | 10:3bc89ef62ce7 | 9 | * |
emilmont | 10:3bc89ef62ce7 | 10 | * Unless required by applicable law or agreed to in writing, software |
emilmont | 10:3bc89ef62ce7 | 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
emilmont | 10:3bc89ef62ce7 | 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
emilmont | 10:3bc89ef62ce7 | 13 | * See the License for the specific language governing permissions and |
emilmont | 10:3bc89ef62ce7 | 14 | * limitations under the License. |
emilmont | 10:3bc89ef62ce7 | 15 | */ |
mbed_official | 227:7bd0639b8911 | 16 | #include "mbed_assert.h" |
emilmont | 10:3bc89ef62ce7 | 17 | #include <math.h> |
emilmont | 10:3bc89ef62ce7 | 18 | |
emilmont | 10:3bc89ef62ce7 | 19 | #include "spi_api.h" |
emilmont | 10:3bc89ef62ce7 | 20 | #include "cmsis.h" |
emilmont | 10:3bc89ef62ce7 | 21 | #include "pinmap.h" |
mbed_official | 286:31249416b6f9 | 22 | #include "mbed_error.h" |
emilmont | 10:3bc89ef62ce7 | 23 | |
emilmont | 10:3bc89ef62ce7 | 24 | static const PinMap PinMap_SPI_SCLK[] = { |
emilmont | 10:3bc89ef62ce7 | 25 | {P0_7 , SPI_1, 2}, |
emilmont | 10:3bc89ef62ce7 | 26 | {P0_15, SPI_0, 2}, |
emilmont | 10:3bc89ef62ce7 | 27 | {P1_20, SPI_0, 3}, |
emilmont | 10:3bc89ef62ce7 | 28 | {P1_31, SPI_1, 2}, |
emilmont | 10:3bc89ef62ce7 | 29 | {NC , NC , 0} |
emilmont | 10:3bc89ef62ce7 | 30 | }; |
emilmont | 10:3bc89ef62ce7 | 31 | |
emilmont | 10:3bc89ef62ce7 | 32 | static const PinMap PinMap_SPI_MOSI[] = { |
emilmont | 10:3bc89ef62ce7 | 33 | {P0_9 , SPI_1, 2}, |
emilmont | 10:3bc89ef62ce7 | 34 | {P0_13, SPI_1, 2}, |
emilmont | 10:3bc89ef62ce7 | 35 | {P0_18, SPI_0, 2}, |
emilmont | 10:3bc89ef62ce7 | 36 | {P1_24, SPI_0, 3}, |
emilmont | 10:3bc89ef62ce7 | 37 | {NC , NC , 0} |
emilmont | 10:3bc89ef62ce7 | 38 | }; |
emilmont | 10:3bc89ef62ce7 | 39 | |
emilmont | 10:3bc89ef62ce7 | 40 | static const PinMap PinMap_SPI_MISO[] = { |
emilmont | 10:3bc89ef62ce7 | 41 | {P0_8 , SPI_1, 2}, |
emilmont | 10:3bc89ef62ce7 | 42 | {P0_12, SPI_1, 2}, |
emilmont | 10:3bc89ef62ce7 | 43 | {P0_17, SPI_0, 2}, |
emilmont | 10:3bc89ef62ce7 | 44 | {P1_23, SPI_0, 3}, |
emilmont | 10:3bc89ef62ce7 | 45 | {NC , NC , 0} |
emilmont | 10:3bc89ef62ce7 | 46 | }; |
emilmont | 10:3bc89ef62ce7 | 47 | |
emilmont | 10:3bc89ef62ce7 | 48 | static const PinMap PinMap_SPI_SSEL[] = { |
emilmont | 10:3bc89ef62ce7 | 49 | {P0_6 , SPI_1, 2}, |
emilmont | 10:3bc89ef62ce7 | 50 | {P0_11, SPI_1, 2}, |
emilmont | 10:3bc89ef62ce7 | 51 | {P0_16, SPI_0, 2}, |
emilmont | 10:3bc89ef62ce7 | 52 | {P1_21, SPI_0, 3}, |
emilmont | 10:3bc89ef62ce7 | 53 | {NC , NC , 0} |
emilmont | 10:3bc89ef62ce7 | 54 | }; |
emilmont | 10:3bc89ef62ce7 | 55 | |
emilmont | 10:3bc89ef62ce7 | 56 | static inline int ssp_disable(spi_t *obj); |
emilmont | 10:3bc89ef62ce7 | 57 | static inline int ssp_enable(spi_t *obj); |
emilmont | 10:3bc89ef62ce7 | 58 | |
emilmont | 10:3bc89ef62ce7 | 59 | void spi_init(spi_t *obj, PinName mosi, PinName miso, PinName sclk, PinName ssel) { |
emilmont | 10:3bc89ef62ce7 | 60 | // determine the SPI to use |
emilmont | 10:3bc89ef62ce7 | 61 | SPIName spi_mosi = (SPIName)pinmap_peripheral(mosi, PinMap_SPI_MOSI); |
emilmont | 10:3bc89ef62ce7 | 62 | SPIName spi_miso = (SPIName)pinmap_peripheral(miso, PinMap_SPI_MISO); |
emilmont | 10:3bc89ef62ce7 | 63 | SPIName spi_sclk = (SPIName)pinmap_peripheral(sclk, PinMap_SPI_SCLK); |
emilmont | 10:3bc89ef62ce7 | 64 | SPIName spi_ssel = (SPIName)pinmap_peripheral(ssel, PinMap_SPI_SSEL); |
emilmont | 10:3bc89ef62ce7 | 65 | SPIName spi_data = (SPIName)pinmap_merge(spi_mosi, spi_miso); |
emilmont | 10:3bc89ef62ce7 | 66 | SPIName spi_cntl = (SPIName)pinmap_merge(spi_sclk, spi_ssel); |
emilmont | 10:3bc89ef62ce7 | 67 | obj->spi = (LPC_SSP_TypeDef*)pinmap_merge(spi_data, spi_cntl); |
mbed_official | 227:7bd0639b8911 | 68 | MBED_ASSERT((int)obj->spi != NC); |
emilmont | 10:3bc89ef62ce7 | 69 | |
emilmont | 10:3bc89ef62ce7 | 70 | // enable power and clocking |
emilmont | 10:3bc89ef62ce7 | 71 | switch ((int)obj->spi) { |
emilmont | 10:3bc89ef62ce7 | 72 | case SPI_0: LPC_SC->PCONP |= 1 << 21; break; |
emilmont | 10:3bc89ef62ce7 | 73 | case SPI_1: LPC_SC->PCONP |= 1 << 10; break; |
emilmont | 10:3bc89ef62ce7 | 74 | } |
emilmont | 10:3bc89ef62ce7 | 75 | |
emilmont | 10:3bc89ef62ce7 | 76 | // set default format and frequency |
emilmont | 10:3bc89ef62ce7 | 77 | if (ssel == NC) { |
emilmont | 10:3bc89ef62ce7 | 78 | spi_format(obj, 8, 0, 0); // 8 bits, mode 0, master |
emilmont | 10:3bc89ef62ce7 | 79 | } else { |
emilmont | 10:3bc89ef62ce7 | 80 | spi_format(obj, 8, 0, 1); // 8 bits, mode 0, slave |
emilmont | 10:3bc89ef62ce7 | 81 | } |
emilmont | 10:3bc89ef62ce7 | 82 | spi_frequency(obj, 1000000); |
emilmont | 10:3bc89ef62ce7 | 83 | |
emilmont | 10:3bc89ef62ce7 | 84 | // enable the ssp channel |
emilmont | 10:3bc89ef62ce7 | 85 | ssp_enable(obj); |
emilmont | 10:3bc89ef62ce7 | 86 | |
emilmont | 10:3bc89ef62ce7 | 87 | // pin out the spi pins |
emilmont | 10:3bc89ef62ce7 | 88 | pinmap_pinout(mosi, PinMap_SPI_MOSI); |
emilmont | 10:3bc89ef62ce7 | 89 | pinmap_pinout(miso, PinMap_SPI_MISO); |
emilmont | 10:3bc89ef62ce7 | 90 | pinmap_pinout(sclk, PinMap_SPI_SCLK); |
emilmont | 10:3bc89ef62ce7 | 91 | if (ssel != NC) { |
emilmont | 10:3bc89ef62ce7 | 92 | pinmap_pinout(ssel, PinMap_SPI_SSEL); |
emilmont | 10:3bc89ef62ce7 | 93 | } |
emilmont | 10:3bc89ef62ce7 | 94 | } |
emilmont | 10:3bc89ef62ce7 | 95 | |
emilmont | 10:3bc89ef62ce7 | 96 | void spi_free(spi_t *obj) {} |
emilmont | 10:3bc89ef62ce7 | 97 | |
emilmont | 10:3bc89ef62ce7 | 98 | void spi_format(spi_t *obj, int bits, int mode, int slave) { |
mbed_official | 227:7bd0639b8911 | 99 | MBED_ASSERT(((bits >= 4) && (bits <= 16)) && ((mode >= 0) && (mode <= 3))); |
emilmont | 10:3bc89ef62ce7 | 100 | ssp_disable(obj); |
emilmont | 10:3bc89ef62ce7 | 101 | |
emilmont | 10:3bc89ef62ce7 | 102 | int polarity = (mode & 0x2) ? 1 : 0; |
emilmont | 10:3bc89ef62ce7 | 103 | int phase = (mode & 0x1) ? 1 : 0; |
emilmont | 10:3bc89ef62ce7 | 104 | |
emilmont | 10:3bc89ef62ce7 | 105 | // set it up |
emilmont | 10:3bc89ef62ce7 | 106 | int DSS = bits - 1; // DSS (data select size) |
emilmont | 10:3bc89ef62ce7 | 107 | int SPO = (polarity) ? 1 : 0; // SPO - clock out polarity |
emilmont | 10:3bc89ef62ce7 | 108 | int SPH = (phase) ? 1 : 0; // SPH - clock out phase |
emilmont | 10:3bc89ef62ce7 | 109 | |
emilmont | 10:3bc89ef62ce7 | 110 | int FRF = 0; // FRF (frame format) = SPI |
emilmont | 10:3bc89ef62ce7 | 111 | uint32_t tmp = obj->spi->CR0; |
emilmont | 10:3bc89ef62ce7 | 112 | tmp &= ~(0xFFFF); |
emilmont | 10:3bc89ef62ce7 | 113 | tmp |= DSS << 0 |
emilmont | 10:3bc89ef62ce7 | 114 | | FRF << 4 |
emilmont | 10:3bc89ef62ce7 | 115 | | SPO << 6 |
emilmont | 10:3bc89ef62ce7 | 116 | | SPH << 7; |
emilmont | 10:3bc89ef62ce7 | 117 | obj->spi->CR0 = tmp; |
emilmont | 10:3bc89ef62ce7 | 118 | |
emilmont | 10:3bc89ef62ce7 | 119 | tmp = obj->spi->CR1; |
emilmont | 10:3bc89ef62ce7 | 120 | tmp &= ~(0xD); |
emilmont | 10:3bc89ef62ce7 | 121 | tmp |= 0 << 0 // LBM - loop back mode - off |
emilmont | 10:3bc89ef62ce7 | 122 | | ((slave) ? 1 : 0) << 2 // MS - master slave mode, 1 = slave |
emilmont | 10:3bc89ef62ce7 | 123 | | 0 << 3; // SOD - slave output disable - na |
emilmont | 10:3bc89ef62ce7 | 124 | obj->spi->CR1 = tmp; |
emilmont | 10:3bc89ef62ce7 | 125 | |
emilmont | 10:3bc89ef62ce7 | 126 | ssp_enable(obj); |
emilmont | 10:3bc89ef62ce7 | 127 | } |
emilmont | 10:3bc89ef62ce7 | 128 | |
emilmont | 10:3bc89ef62ce7 | 129 | void spi_frequency(spi_t *obj, int hz) { |
emilmont | 10:3bc89ef62ce7 | 130 | ssp_disable(obj); |
emilmont | 10:3bc89ef62ce7 | 131 | |
emilmont | 10:3bc89ef62ce7 | 132 | // setup the spi clock diveder to /1 |
emilmont | 10:3bc89ef62ce7 | 133 | switch ((int)obj->spi) { |
emilmont | 10:3bc89ef62ce7 | 134 | case SPI_0: |
emilmont | 10:3bc89ef62ce7 | 135 | LPC_SC->PCLKSEL1 &= ~(3 << 10); |
emilmont | 10:3bc89ef62ce7 | 136 | LPC_SC->PCLKSEL1 |= (1 << 10); |
emilmont | 10:3bc89ef62ce7 | 137 | break; |
emilmont | 10:3bc89ef62ce7 | 138 | case SPI_1: |
emilmont | 10:3bc89ef62ce7 | 139 | LPC_SC->PCLKSEL0 &= ~(3 << 20); |
emilmont | 10:3bc89ef62ce7 | 140 | LPC_SC->PCLKSEL0 |= (1 << 20); |
emilmont | 10:3bc89ef62ce7 | 141 | break; |
emilmont | 10:3bc89ef62ce7 | 142 | } |
emilmont | 10:3bc89ef62ce7 | 143 | |
emilmont | 10:3bc89ef62ce7 | 144 | uint32_t PCLK = SystemCoreClock; |
emilmont | 10:3bc89ef62ce7 | 145 | |
emilmont | 10:3bc89ef62ce7 | 146 | int prescaler; |
emilmont | 10:3bc89ef62ce7 | 147 | |
emilmont | 10:3bc89ef62ce7 | 148 | for (prescaler = 2; prescaler <= 254; prescaler += 2) { |
emilmont | 10:3bc89ef62ce7 | 149 | int prescale_hz = PCLK / prescaler; |
emilmont | 10:3bc89ef62ce7 | 150 | |
emilmont | 10:3bc89ef62ce7 | 151 | // calculate the divider |
emilmont | 10:3bc89ef62ce7 | 152 | int divider = floor(((float)prescale_hz / (float)hz) + 0.5f); |
emilmont | 10:3bc89ef62ce7 | 153 | |
emilmont | 10:3bc89ef62ce7 | 154 | // check we can support the divider |
emilmont | 10:3bc89ef62ce7 | 155 | if (divider < 256) { |
emilmont | 10:3bc89ef62ce7 | 156 | // prescaler |
emilmont | 10:3bc89ef62ce7 | 157 | obj->spi->CPSR = prescaler; |
emilmont | 10:3bc89ef62ce7 | 158 | |
emilmont | 10:3bc89ef62ce7 | 159 | // divider |
emilmont | 10:3bc89ef62ce7 | 160 | obj->spi->CR0 &= ~(0xFFFF << 8); |
emilmont | 10:3bc89ef62ce7 | 161 | obj->spi->CR0 |= (divider - 1) << 8; |
emilmont | 10:3bc89ef62ce7 | 162 | ssp_enable(obj); |
emilmont | 10:3bc89ef62ce7 | 163 | return; |
emilmont | 10:3bc89ef62ce7 | 164 | } |
emilmont | 10:3bc89ef62ce7 | 165 | } |
emilmont | 10:3bc89ef62ce7 | 166 | error("Couldn't setup requested SPI frequency"); |
emilmont | 10:3bc89ef62ce7 | 167 | } |
emilmont | 10:3bc89ef62ce7 | 168 | |
emilmont | 10:3bc89ef62ce7 | 169 | static inline int ssp_disable(spi_t *obj) { |
emilmont | 10:3bc89ef62ce7 | 170 | return obj->spi->CR1 &= ~(1 << 1); |
emilmont | 10:3bc89ef62ce7 | 171 | } |
emilmont | 10:3bc89ef62ce7 | 172 | |
emilmont | 10:3bc89ef62ce7 | 173 | static inline int ssp_enable(spi_t *obj) { |
emilmont | 10:3bc89ef62ce7 | 174 | return obj->spi->CR1 |= (1 << 1); |
emilmont | 10:3bc89ef62ce7 | 175 | } |
emilmont | 10:3bc89ef62ce7 | 176 | |
emilmont | 10:3bc89ef62ce7 | 177 | static inline int ssp_readable(spi_t *obj) { |
emilmont | 10:3bc89ef62ce7 | 178 | return obj->spi->SR & (1 << 2); |
emilmont | 10:3bc89ef62ce7 | 179 | } |
emilmont | 10:3bc89ef62ce7 | 180 | |
emilmont | 10:3bc89ef62ce7 | 181 | static inline int ssp_writeable(spi_t *obj) { |
emilmont | 10:3bc89ef62ce7 | 182 | return obj->spi->SR & (1 << 1); |
emilmont | 10:3bc89ef62ce7 | 183 | } |
emilmont | 10:3bc89ef62ce7 | 184 | |
emilmont | 10:3bc89ef62ce7 | 185 | static inline void ssp_write(spi_t *obj, int value) { |
emilmont | 10:3bc89ef62ce7 | 186 | while (!ssp_writeable(obj)); |
emilmont | 10:3bc89ef62ce7 | 187 | obj->spi->DR = value; |
emilmont | 10:3bc89ef62ce7 | 188 | } |
emilmont | 10:3bc89ef62ce7 | 189 | |
emilmont | 10:3bc89ef62ce7 | 190 | static inline int ssp_read(spi_t *obj) { |
emilmont | 10:3bc89ef62ce7 | 191 | while (!ssp_readable(obj)); |
emilmont | 10:3bc89ef62ce7 | 192 | return obj->spi->DR; |
emilmont | 10:3bc89ef62ce7 | 193 | } |
emilmont | 10:3bc89ef62ce7 | 194 | |
emilmont | 10:3bc89ef62ce7 | 195 | static inline int ssp_busy(spi_t *obj) { |
emilmont | 10:3bc89ef62ce7 | 196 | return (obj->spi->SR & (1 << 4)) ? (1) : (0); |
emilmont | 10:3bc89ef62ce7 | 197 | } |
emilmont | 10:3bc89ef62ce7 | 198 | |
emilmont | 10:3bc89ef62ce7 | 199 | int spi_master_write(spi_t *obj, int value) { |
emilmont | 10:3bc89ef62ce7 | 200 | ssp_write(obj, value); |
emilmont | 10:3bc89ef62ce7 | 201 | return ssp_read(obj); |
emilmont | 10:3bc89ef62ce7 | 202 | } |
emilmont | 10:3bc89ef62ce7 | 203 | |
emilmont | 10:3bc89ef62ce7 | 204 | int spi_slave_receive(spi_t *obj) { |
emilmont | 10:3bc89ef62ce7 | 205 | return (ssp_readable(obj) && !ssp_busy(obj)) ? (1) : (0); |
mbed_official | 81:a9456fdf72fa | 206 | } |
emilmont | 10:3bc89ef62ce7 | 207 | |
emilmont | 10:3bc89ef62ce7 | 208 | int spi_slave_read(spi_t *obj) { |
emilmont | 10:3bc89ef62ce7 | 209 | return obj->spi->DR; |
emilmont | 10:3bc89ef62ce7 | 210 | } |
emilmont | 10:3bc89ef62ce7 | 211 | |
emilmont | 10:3bc89ef62ce7 | 212 | void spi_slave_write(spi_t *obj, int value) { |
emilmont | 10:3bc89ef62ce7 | 213 | while (ssp_writeable(obj) == 0) ; |
emilmont | 10:3bc89ef62ce7 | 214 | obj->spi->DR = value; |
emilmont | 10:3bc89ef62ce7 | 215 | } |
emilmont | 10:3bc89ef62ce7 | 216 | |
emilmont | 10:3bc89ef62ce7 | 217 | int spi_busy(spi_t *obj) { |
emilmont | 10:3bc89ef62ce7 | 218 | return ssp_busy(obj); |
emilmont | 10:3bc89ef62ce7 | 219 | } |