mbed library sources: Modified to operate FRDM-KL25Z at 48MHz from internal 32kHz oscillator (nothing else changed).
Fork of mbed-src by
The only file that changed is: mbed-src-FLL48/targets/cmsis/TARGET_Freescale/TARGET_KL25Z/system_MKL25Z4.h
targets/hal/TARGET_STM/TARGET_STM32F4XX/spi_api.c@20:4263a77256ae, 2013-09-10 (annotated)
- Committer:
- bogdanm
- Date:
- Tue Sep 10 15:14:19 2013 +0300
- Revision:
- 20:4263a77256ae
Sync with git revision 171dda705c947bf910926a0b73d6a4797802554d
Who changed what in which revision?
User | Revision | Line number | New contents of line |
---|---|---|---|
bogdanm | 20:4263a77256ae | 1 | /* mbed Microcontroller Library |
bogdanm | 20:4263a77256ae | 2 | * Copyright (c) 2006-2013 ARM Limited |
bogdanm | 20:4263a77256ae | 3 | * |
bogdanm | 20:4263a77256ae | 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
bogdanm | 20:4263a77256ae | 5 | * you may not use this file except in compliance with the License. |
bogdanm | 20:4263a77256ae | 6 | * You may obtain a copy of the License at |
bogdanm | 20:4263a77256ae | 7 | * |
bogdanm | 20:4263a77256ae | 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
bogdanm | 20:4263a77256ae | 9 | * |
bogdanm | 20:4263a77256ae | 10 | * Unless required by applicable law or agreed to in writing, software |
bogdanm | 20:4263a77256ae | 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
bogdanm | 20:4263a77256ae | 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
bogdanm | 20:4263a77256ae | 13 | * See the License for the specific language governing permissions and |
bogdanm | 20:4263a77256ae | 14 | * limitations under the License. |
bogdanm | 20:4263a77256ae | 15 | */ |
bogdanm | 20:4263a77256ae | 16 | #include "spi_api.h" |
bogdanm | 20:4263a77256ae | 17 | |
bogdanm | 20:4263a77256ae | 18 | #if DEVICE_SPI |
bogdanm | 20:4263a77256ae | 19 | #include <math.h> |
bogdanm | 20:4263a77256ae | 20 | |
bogdanm | 20:4263a77256ae | 21 | #include "cmsis.h" |
bogdanm | 20:4263a77256ae | 22 | #include "pinmap.h" |
bogdanm | 20:4263a77256ae | 23 | #include "error.h" |
bogdanm | 20:4263a77256ae | 24 | |
bogdanm | 20:4263a77256ae | 25 | static const PinMap PinMap_SPI_SCLK[] = { |
bogdanm | 20:4263a77256ae | 26 | {PA_5, SPI_1, STM_PIN_DATA(2, 5)}, |
bogdanm | 20:4263a77256ae | 27 | {PB_3, SPI_1, STM_PIN_DATA(2, 5)}, |
bogdanm | 20:4263a77256ae | 28 | {PB_3, SPI_3, STM_PIN_DATA(2, 6)}, |
bogdanm | 20:4263a77256ae | 29 | {PB_10, SPI_2, STM_PIN_DATA(2, 5)}, |
bogdanm | 20:4263a77256ae | 30 | {PB_13, SPI_2, STM_PIN_DATA(2, 5)}, |
bogdanm | 20:4263a77256ae | 31 | {PC_10, SPI_3, STM_PIN_DATA(2, 6)}, |
bogdanm | 20:4263a77256ae | 32 | {NC, NC, 0} |
bogdanm | 20:4263a77256ae | 33 | }; |
bogdanm | 20:4263a77256ae | 34 | |
bogdanm | 20:4263a77256ae | 35 | static const PinMap PinMap_SPI_MOSI[] = { |
bogdanm | 20:4263a77256ae | 36 | {PA_7, SPI_1, STM_PIN_DATA(2, 5)}, |
bogdanm | 20:4263a77256ae | 37 | {PB_5, SPI_1, STM_PIN_DATA(2, 5)}, |
bogdanm | 20:4263a77256ae | 38 | {PB_5, SPI_3, STM_PIN_DATA(2, 6)}, |
bogdanm | 20:4263a77256ae | 39 | {PB_15, SPI_2, STM_PIN_DATA(2, 5)}, |
bogdanm | 20:4263a77256ae | 40 | {PC_3, SPI_2, STM_PIN_DATA(2, 5)}, |
bogdanm | 20:4263a77256ae | 41 | {PC_12, SPI_3, STM_PIN_DATA(2, 6)}, |
bogdanm | 20:4263a77256ae | 42 | {NC, NC, 0} |
bogdanm | 20:4263a77256ae | 43 | }; |
bogdanm | 20:4263a77256ae | 44 | |
bogdanm | 20:4263a77256ae | 45 | static const PinMap PinMap_SPI_MISO[] = { |
bogdanm | 20:4263a77256ae | 46 | {PA_6, SPI_1, STM_PIN_DATA(2, 5)}, |
bogdanm | 20:4263a77256ae | 47 | {PB_4, SPI_1, STM_PIN_DATA(2, 5)}, |
bogdanm | 20:4263a77256ae | 48 | {PB_4, SPI_3, STM_PIN_DATA(2, 6)}, |
bogdanm | 20:4263a77256ae | 49 | {PB_14, SPI_2, STM_PIN_DATA(2, 5)}, |
bogdanm | 20:4263a77256ae | 50 | {PC_2, SPI_2, STM_PIN_DATA(2, 5)}, |
bogdanm | 20:4263a77256ae | 51 | {PC_11, SPI_3, STM_PIN_DATA(2, 6)}, |
bogdanm | 20:4263a77256ae | 52 | {NC, NC, 0} |
bogdanm | 20:4263a77256ae | 53 | }; |
bogdanm | 20:4263a77256ae | 54 | |
bogdanm | 20:4263a77256ae | 55 | static const PinMap PinMap_SPI_SSEL[] = { |
bogdanm | 20:4263a77256ae | 56 | {PA_4, SPI_1, STM_PIN_DATA(2, 5)}, |
bogdanm | 20:4263a77256ae | 57 | {PA_4, SPI_3, STM_PIN_DATA(2, 6)}, |
bogdanm | 20:4263a77256ae | 58 | {PA_15, SPI_1, STM_PIN_DATA(2, 5)}, |
bogdanm | 20:4263a77256ae | 59 | {PA_15, SPI_3, STM_PIN_DATA(2, 6)}, |
bogdanm | 20:4263a77256ae | 60 | {PB_9, SPI_2, STM_PIN_DATA(2, 5)}, |
bogdanm | 20:4263a77256ae | 61 | {PB_12, SPI_2, STM_PIN_DATA(2, 5)}, |
bogdanm | 20:4263a77256ae | 62 | {NC, NC, 0} |
bogdanm | 20:4263a77256ae | 63 | }; |
bogdanm | 20:4263a77256ae | 64 | |
bogdanm | 20:4263a77256ae | 65 | |
bogdanm | 20:4263a77256ae | 66 | static inline int ssp_disable(spi_t *obj); |
bogdanm | 20:4263a77256ae | 67 | static inline int ssp_enable(spi_t *obj); |
bogdanm | 20:4263a77256ae | 68 | |
bogdanm | 20:4263a77256ae | 69 | void spi_init(spi_t *obj, PinName mosi, PinName miso, PinName sclk, PinName ssel) { |
bogdanm | 20:4263a77256ae | 70 | // determine the SPI to use |
bogdanm | 20:4263a77256ae | 71 | SPIName spi_mosi = (SPIName)pinmap_peripheral(mosi, PinMap_SPI_MOSI); |
bogdanm | 20:4263a77256ae | 72 | SPIName spi_miso = (SPIName)pinmap_peripheral(miso, PinMap_SPI_MISO); |
bogdanm | 20:4263a77256ae | 73 | SPIName spi_sclk = (SPIName)pinmap_peripheral(sclk, PinMap_SPI_SCLK); |
bogdanm | 20:4263a77256ae | 74 | SPIName spi_ssel = (SPIName)pinmap_peripheral(ssel, PinMap_SPI_SSEL); |
bogdanm | 20:4263a77256ae | 75 | SPIName spi_data = (SPIName)pinmap_merge(spi_mosi, spi_miso); |
bogdanm | 20:4263a77256ae | 76 | SPIName spi_cntl = (SPIName)pinmap_merge(spi_sclk, spi_ssel); |
bogdanm | 20:4263a77256ae | 77 | obj->spi = (SPI_TypeDef*)pinmap_merge(spi_data, spi_cntl); |
bogdanm | 20:4263a77256ae | 78 | if ((int)obj->spi == NC) { |
bogdanm | 20:4263a77256ae | 79 | error("SPI pinout mapping failed"); |
bogdanm | 20:4263a77256ae | 80 | } |
bogdanm | 20:4263a77256ae | 81 | |
bogdanm | 20:4263a77256ae | 82 | // enable power and clocking |
bogdanm | 20:4263a77256ae | 83 | switch ((int)obj->spi) { |
bogdanm | 20:4263a77256ae | 84 | case SPI_1: |
bogdanm | 20:4263a77256ae | 85 | RCC->AHB1ENR |= RCC_AHB1ENR_GPIOAEN | RCC_AHB1ENR_GPIOBEN; |
bogdanm | 20:4263a77256ae | 86 | RCC->APB2ENR |= RCC_APB2ENR_SPI1EN; |
bogdanm | 20:4263a77256ae | 87 | break; |
bogdanm | 20:4263a77256ae | 88 | case SPI_2: |
bogdanm | 20:4263a77256ae | 89 | RCC->AHB1ENR |= RCC_AHB1ENR_GPIOBEN | RCC_AHB1ENR_GPIOCEN; |
bogdanm | 20:4263a77256ae | 90 | RCC->APB1ENR |= RCC_APB1ENR_SPI2EN; |
bogdanm | 20:4263a77256ae | 91 | break; |
bogdanm | 20:4263a77256ae | 92 | case SPI_3: |
bogdanm | 20:4263a77256ae | 93 | RCC->AHB1ENR |= RCC_AHB1ENR_GPIOBEN | RCC_AHB1ENR_GPIOCEN; |
bogdanm | 20:4263a77256ae | 94 | RCC->APB1ENR |= RCC_APB1ENR_SPI3EN; |
bogdanm | 20:4263a77256ae | 95 | break; |
bogdanm | 20:4263a77256ae | 96 | } |
bogdanm | 20:4263a77256ae | 97 | |
bogdanm | 20:4263a77256ae | 98 | |
bogdanm | 20:4263a77256ae | 99 | // set default format and frequency |
bogdanm | 20:4263a77256ae | 100 | if (ssel == NC) { |
bogdanm | 20:4263a77256ae | 101 | spi_format(obj, 8, 0, 0); // 8 bits, mode 0, master |
bogdanm | 20:4263a77256ae | 102 | } else { |
bogdanm | 20:4263a77256ae | 103 | spi_format(obj, 8, 0, 1); // 8 bits, mode 0, slave |
bogdanm | 20:4263a77256ae | 104 | } |
bogdanm | 20:4263a77256ae | 105 | spi_frequency(obj, 1000000); |
bogdanm | 20:4263a77256ae | 106 | |
bogdanm | 20:4263a77256ae | 107 | // enable the ssp channel |
bogdanm | 20:4263a77256ae | 108 | ssp_enable(obj); |
bogdanm | 20:4263a77256ae | 109 | |
bogdanm | 20:4263a77256ae | 110 | // pin out the spi pins |
bogdanm | 20:4263a77256ae | 111 | pinmap_pinout(mosi, PinMap_SPI_MOSI); |
bogdanm | 20:4263a77256ae | 112 | pinmap_pinout(miso, PinMap_SPI_MISO); |
bogdanm | 20:4263a77256ae | 113 | pinmap_pinout(sclk, PinMap_SPI_SCLK); |
bogdanm | 20:4263a77256ae | 114 | if (ssel != NC) { |
bogdanm | 20:4263a77256ae | 115 | pinmap_pinout(ssel, PinMap_SPI_SSEL); |
bogdanm | 20:4263a77256ae | 116 | } |
bogdanm | 20:4263a77256ae | 117 | else { |
bogdanm | 20:4263a77256ae | 118 | // Use software slave management |
bogdanm | 20:4263a77256ae | 119 | obj->spi->CR1 |= SPI_CR1_SSM | SPI_CR1_SSI; |
bogdanm | 20:4263a77256ae | 120 | } |
bogdanm | 20:4263a77256ae | 121 | } |
bogdanm | 20:4263a77256ae | 122 | |
bogdanm | 20:4263a77256ae | 123 | void spi_free(spi_t *obj) {} |
bogdanm | 20:4263a77256ae | 124 | |
bogdanm | 20:4263a77256ae | 125 | void spi_format(spi_t *obj, int bits, int mode, int slave) { |
bogdanm | 20:4263a77256ae | 126 | ssp_disable(obj); |
bogdanm | 20:4263a77256ae | 127 | |
bogdanm | 20:4263a77256ae | 128 | if (!(bits == 8 || bits == 16) || !(mode >= 0 && mode <= 3)) { |
bogdanm | 20:4263a77256ae | 129 | error("SPI format error"); |
bogdanm | 20:4263a77256ae | 130 | } |
bogdanm | 20:4263a77256ae | 131 | |
bogdanm | 20:4263a77256ae | 132 | |
bogdanm | 20:4263a77256ae | 133 | int polarity = (mode & 0x2) ? 1 : 0; |
bogdanm | 20:4263a77256ae | 134 | int phase = (mode & 0x1) ? 1 : 0; |
bogdanm | 20:4263a77256ae | 135 | |
bogdanm | 20:4263a77256ae | 136 | obj->spi->CR1 &= ~0x807; |
bogdanm | 20:4263a77256ae | 137 | obj->spi->CR1 |= ((phase) ? 1 : 0) << 0 | |
bogdanm | 20:4263a77256ae | 138 | ((polarity) ? 1 : 0) << 1 | |
bogdanm | 20:4263a77256ae | 139 | ((slave) ? 0: 1) << 2 | |
bogdanm | 20:4263a77256ae | 140 | ((bits == 16) ? 1 : 0) << 11; |
bogdanm | 20:4263a77256ae | 141 | |
bogdanm | 20:4263a77256ae | 142 | if (obj->spi->SR & SPI_SR_MODF) { |
bogdanm | 20:4263a77256ae | 143 | obj->spi->CR1 = obj->spi->CR1; |
bogdanm | 20:4263a77256ae | 144 | } |
bogdanm | 20:4263a77256ae | 145 | |
bogdanm | 20:4263a77256ae | 146 | ssp_enable(obj); |
bogdanm | 20:4263a77256ae | 147 | } |
bogdanm | 20:4263a77256ae | 148 | |
bogdanm | 20:4263a77256ae | 149 | void spi_frequency(spi_t *obj, int hz) { |
bogdanm | 20:4263a77256ae | 150 | ssp_disable(obj); |
bogdanm | 20:4263a77256ae | 151 | |
bogdanm | 20:4263a77256ae | 152 | // SPI1 runs from PCLK2, which runs at SystemCoreClock / 2. SPI2 and SPI3 |
bogdanm | 20:4263a77256ae | 153 | // run from PCLK1, which runs at SystemCoreClock / 4. |
bogdanm | 20:4263a77256ae | 154 | uint32_t PCLK = SystemCoreClock; |
bogdanm | 20:4263a77256ae | 155 | switch ((int)obj->spi) { |
bogdanm | 20:4263a77256ae | 156 | case SPI_1: PCLK = PCLK >> 1; break; |
bogdanm | 20:4263a77256ae | 157 | case SPI_2: PCLK = PCLK >> 2; break; |
bogdanm | 20:4263a77256ae | 158 | case SPI_3: PCLK = PCLK >> 2; break; |
bogdanm | 20:4263a77256ae | 159 | } |
bogdanm | 20:4263a77256ae | 160 | |
bogdanm | 20:4263a77256ae | 161 | // Choose the baud rate divisor (between 2 and 256) |
bogdanm | 20:4263a77256ae | 162 | uint32_t divisor = PCLK / hz; |
bogdanm | 20:4263a77256ae | 163 | |
bogdanm | 20:4263a77256ae | 164 | // Find the nearest power-of-2 |
bogdanm | 20:4263a77256ae | 165 | divisor = divisor > 0 ? divisor-1 : 0; |
bogdanm | 20:4263a77256ae | 166 | divisor |= divisor >> 1; |
bogdanm | 20:4263a77256ae | 167 | divisor |= divisor >> 2; |
bogdanm | 20:4263a77256ae | 168 | divisor |= divisor >> 4; |
bogdanm | 20:4263a77256ae | 169 | divisor |= divisor >> 8; |
bogdanm | 20:4263a77256ae | 170 | divisor |= divisor >> 16; |
bogdanm | 20:4263a77256ae | 171 | divisor++; |
bogdanm | 20:4263a77256ae | 172 | |
bogdanm | 20:4263a77256ae | 173 | uint32_t baud_rate = __builtin_ffs(divisor) - 1; |
bogdanm | 20:4263a77256ae | 174 | baud_rate = baud_rate > 0x7 ? 0x7 : baud_rate; |
bogdanm | 20:4263a77256ae | 175 | |
bogdanm | 20:4263a77256ae | 176 | obj->spi->CR1 &= ~(0x7 << 3); |
bogdanm | 20:4263a77256ae | 177 | obj->spi->CR1 |= baud_rate << 3; |
bogdanm | 20:4263a77256ae | 178 | |
bogdanm | 20:4263a77256ae | 179 | ssp_enable(obj); |
bogdanm | 20:4263a77256ae | 180 | } |
bogdanm | 20:4263a77256ae | 181 | |
bogdanm | 20:4263a77256ae | 182 | static inline int ssp_disable(spi_t *obj) { |
bogdanm | 20:4263a77256ae | 183 | // TODO: Follow the instructions in 25.3.8 for safely disabling the SPI |
bogdanm | 20:4263a77256ae | 184 | return obj->spi->CR1 &= ~SPI_CR1_SPE; |
bogdanm | 20:4263a77256ae | 185 | } |
bogdanm | 20:4263a77256ae | 186 | |
bogdanm | 20:4263a77256ae | 187 | static inline int ssp_enable(spi_t *obj) { |
bogdanm | 20:4263a77256ae | 188 | return obj->spi->CR1 |= SPI_CR1_SPE; |
bogdanm | 20:4263a77256ae | 189 | } |
bogdanm | 20:4263a77256ae | 190 | |
bogdanm | 20:4263a77256ae | 191 | static inline int ssp_readable(spi_t *obj) { |
bogdanm | 20:4263a77256ae | 192 | return obj->spi->SR & SPI_SR_RXNE; |
bogdanm | 20:4263a77256ae | 193 | } |
bogdanm | 20:4263a77256ae | 194 | |
bogdanm | 20:4263a77256ae | 195 | static inline int ssp_writeable(spi_t *obj) { |
bogdanm | 20:4263a77256ae | 196 | return obj->spi->SR & SPI_SR_TXE; |
bogdanm | 20:4263a77256ae | 197 | } |
bogdanm | 20:4263a77256ae | 198 | |
bogdanm | 20:4263a77256ae | 199 | static inline void ssp_write(spi_t *obj, int value) { |
bogdanm | 20:4263a77256ae | 200 | while (!ssp_writeable(obj)); |
bogdanm | 20:4263a77256ae | 201 | obj->spi->DR = value; |
bogdanm | 20:4263a77256ae | 202 | } |
bogdanm | 20:4263a77256ae | 203 | |
bogdanm | 20:4263a77256ae | 204 | static inline int ssp_read(spi_t *obj) { |
bogdanm | 20:4263a77256ae | 205 | while (!ssp_readable(obj)); |
bogdanm | 20:4263a77256ae | 206 | return obj->spi->DR; |
bogdanm | 20:4263a77256ae | 207 | } |
bogdanm | 20:4263a77256ae | 208 | |
bogdanm | 20:4263a77256ae | 209 | static inline int ssp_busy(spi_t *obj) { |
bogdanm | 20:4263a77256ae | 210 | return (obj->spi->SR & SPI_SR_BSY) ? (1) : (0); |
bogdanm | 20:4263a77256ae | 211 | } |
bogdanm | 20:4263a77256ae | 212 | |
bogdanm | 20:4263a77256ae | 213 | int spi_master_write(spi_t *obj, int value) { |
bogdanm | 20:4263a77256ae | 214 | ssp_write(obj, value); |
bogdanm | 20:4263a77256ae | 215 | return ssp_read(obj); |
bogdanm | 20:4263a77256ae | 216 | } |
bogdanm | 20:4263a77256ae | 217 | |
bogdanm | 20:4263a77256ae | 218 | int spi_slave_receive(spi_t *obj) { |
bogdanm | 20:4263a77256ae | 219 | return (ssp_readable(obj) && !ssp_busy(obj)) ? (1) : (0); |
bogdanm | 20:4263a77256ae | 220 | }; |
bogdanm | 20:4263a77256ae | 221 | |
bogdanm | 20:4263a77256ae | 222 | int spi_slave_read(spi_t *obj) { |
bogdanm | 20:4263a77256ae | 223 | return obj->spi->DR; |
bogdanm | 20:4263a77256ae | 224 | } |
bogdanm | 20:4263a77256ae | 225 | |
bogdanm | 20:4263a77256ae | 226 | void spi_slave_write(spi_t *obj, int value) { |
bogdanm | 20:4263a77256ae | 227 | while (ssp_writeable(obj) == 0) ; |
bogdanm | 20:4263a77256ae | 228 | obj->spi->DR = value; |
bogdanm | 20:4263a77256ae | 229 | } |
bogdanm | 20:4263a77256ae | 230 | |
bogdanm | 20:4263a77256ae | 231 | int spi_busy(spi_t *obj) { |
bogdanm | 20:4263a77256ae | 232 | return ssp_busy(obj); |
bogdanm | 20:4263a77256ae | 233 | } |
bogdanm | 20:4263a77256ae | 234 | |
bogdanm | 20:4263a77256ae | 235 | #endif |