mirror of https://github.com/ARMmbed/mbed-os.git
404 lines
9.5 KiB
C
404 lines
9.5 KiB
C
/* mbed Microcontroller Library
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* Copyright (c) 2006-2013 ARM Limited
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#include "mbed_assert.h"
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#include <math.h>
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#include "spi_api.h"
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#include "cmsis.h"
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#include "pinmap.h"
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#include "mbed_error.h"
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static const SWM_Map SWM_SPI_SSEL[] = {
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{4, 0},
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{5, 24},
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};
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static const SWM_Map SWM_SPI_SCLK[] = {
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{3, 8},
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{5, 0},
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};
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static const SWM_Map SWM_SPI_MOSI[] = {
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{3, 16},
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{5, 8},
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};
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static const SWM_Map SWM_SPI_MISO[] = {
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{3, 24},
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{5, 16},
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};
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// Pinmap used for testing only
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static const PinMap PinMap_SPI_testing[] = {
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{P0_0, 0, 0},
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{P0_1, 0, 0},
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{P0_2, 0, 0},
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{P0_3, 0, 0},
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{P0_4, 0, 0},
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{P0_5, 0, 0},
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{P0_6, 0, 0},
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{P0_7, 0, 0},
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{P0_8, 0, 0},
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{P0_9, 0, 0},
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{P0_10, 0, 0},
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{P0_11, 0, 0},
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{P0_12, 0, 0},
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{P0_13, 0, 0},
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{P0_14, 0, 0},
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{P0_15, 0, 0},
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{P0_16, 0, 0},
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{P0_17, 0, 0},
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{P0_18, 0, 0},
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{P0_19, 0, 0},
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{P0_20, 0, 0},
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{P0_21, 0, 0},
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{P0_22, 0, 0},
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{P0_23, 0, 0},
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{P0_24, 0, 0},
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{P0_25, 0, 0},
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{P0_26, 0, 0},
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{P0_27, 0, 0},
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{P0_28, 0, 0},
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{P0_29, 0, 0},
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{P0_30, 0, 0},
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{P0_31, 0, 0},
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{P1_0, 0, 0},
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{P1_1, 0, 0},
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{P1_2, 0, 0},
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{P1_3, 0, 0},
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{P1_4, 0, 0},
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{P1_5, 0, 0},
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{P1_6, 0, 0},
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{P1_7, 0, 0},
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{P1_8, 0, 0},
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{P1_9, 0, 0},
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{P1_10, 0, 0},
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{P1_11, 0, 0},
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{P1_12, 0, 0},
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{P1_13, 0, 0},
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{P1_14, 0, 0},
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{P1_15, 0, 0},
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{P1_16, 0, 0},
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{P1_17, 0, 0},
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{P1_18, 0, 0},
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{P1_19, 0, 0},
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{P1_20, 0, 0},
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{P1_21, 0, 0},
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{P1_22, 0, 0},
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{P1_23, 0, 0},
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{P1_24, 0, 0},
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{P1_25, 0, 0},
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{P1_26, 0, 0},
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{P1_27, 0, 0},
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{P1_28, 0, 0},
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{P1_29, 0, 0},
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{P1_30, 0, 0},
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{P1_31, 0, 0},
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{P2_0, 0, 0},
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{P2_1, 0, 0},
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{P2_2, 0, 0},
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{P2_3, 0, 0},
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{P2_4, 0, 0},
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{P2_5, 0, 0},
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{P2_6, 0, 0},
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{P2_7, 0, 0},
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{P2_8, 0, 0},
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{P2_9, 0, 0},
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{P2_10, 0, 0},
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{P2_11, 0, 0},
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{P2_12, 0, 0},
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{NC, NC, 0}
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};
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// bit flags for used SPIs
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static unsigned char spi_used = 0;
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static int get_available_spi(PinName mosi, PinName miso, PinName sclk, PinName ssel)
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{
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if (spi_used == 0) {
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return 0; // The first user
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}
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const SWM_Map *swm;
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uint32_t regVal;
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// Investigate if same pins as the used SPI0/1 - to be able to reuse it
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for (int spi_n = 0; spi_n < 2; spi_n++) {
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if (spi_used & (1<<spi_n)) {
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if (sclk != NC) {
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swm = &SWM_SPI_SCLK[spi_n];
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regVal = LPC_SWM->PINASSIGN[swm->n] & (0xFF << swm->offset);
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if (regVal != (sclk << swm->offset)) {
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// Existing pin is not the same as the one we want
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continue;
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}
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}
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if (mosi != NC) {
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swm = &SWM_SPI_MOSI[spi_n];
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regVal = LPC_SWM->PINASSIGN[swm->n] & (0xFF << swm->offset);
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if (regVal != (mosi << swm->offset)) {
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// Existing pin is not the same as the one we want
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continue;
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}
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}
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if (miso != NC) {
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swm = &SWM_SPI_MISO[spi_n];
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regVal = LPC_SWM->PINASSIGN[swm->n] & (0xFF << swm->offset);
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if (regVal != (miso << swm->offset)) {
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// Existing pin is not the same as the one we want
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continue;
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}
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}
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if (ssel != NC) {
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swm = &SWM_SPI_SSEL[spi_n];
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regVal = LPC_SWM->PINASSIGN[swm->n] & (0xFF << swm->offset);
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if (regVal != (ssel << swm->offset)) {
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// Existing pin is not the same as the one we want
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continue;
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}
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}
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// The pins for the currently used SPIx are the same as the
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// ones we want so we will reuse it
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return spi_n;
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}
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}
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// None of the existing SPIx pin setups match the pins we want
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// so the last hope is to select one unused SPIx
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if ((spi_used & 1) == 0) {
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return 0;
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} else if ((spi_used & 2) == 0) {
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return 1;
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}
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// No matching setup and no free SPIx
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return -1;
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}
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static inline void spi_disable(spi_t *obj);
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static inline void spi_enable(spi_t *obj);
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void spi_init(spi_t *obj, PinName mosi, PinName miso, PinName sclk, PinName ssel)
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{
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int spi_n = get_available_spi(mosi, miso, sclk, ssel);
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if (spi_n == -1) {
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error("No available SPI");
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}
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obj->spi_n = spi_n;
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spi_used |= (1 << spi_n);
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obj->spi = (spi_n) ? (LPC_SPI0_Type *)(LPC_SPI1_BASE) : (LPC_SPI0_Type *)(LPC_SPI0_BASE);
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const SWM_Map *swm;
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uint32_t regVal;
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if (sclk != NC) {
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swm = &SWM_SPI_SCLK[obj->spi_n];
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regVal = LPC_SWM->PINASSIGN[swm->n] & ~(0xFF << swm->offset);
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LPC_SWM->PINASSIGN[swm->n] = regVal | (sclk << swm->offset);
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}
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if (mosi != NC) {
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swm = &SWM_SPI_MOSI[obj->spi_n];
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regVal = LPC_SWM->PINASSIGN[swm->n] & ~(0xFF << swm->offset);
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LPC_SWM->PINASSIGN[swm->n] = regVal | (mosi << swm->offset);
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}
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if (miso != NC) {
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swm = &SWM_SPI_MISO[obj->spi_n];
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regVal = LPC_SWM->PINASSIGN[swm->n] & ~(0xFF << swm->offset);
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LPC_SWM->PINASSIGN[swm->n] = regVal | (miso << swm->offset);
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}
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if (ssel != NC) {
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swm = &SWM_SPI_SSEL[obj->spi_n];
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regVal = LPC_SWM->PINASSIGN[swm->n] & ~(0xFF << swm->offset);
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LPC_SWM->PINASSIGN[swm->n] = regVal | (ssel << swm->offset);
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}
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// clear interrupts
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obj->spi->INTENCLR = 0x3f;
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// enable power and clocking
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LPC_SYSCON->SYSAHBCLKCTRL1 |= (0x1 << (obj->spi_n + 9));
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LPC_SYSCON->PRESETCTRL1 |= (0x1 << (obj->spi_n + 9));
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LPC_SYSCON->PRESETCTRL1 &= ~(0x1 << (obj->spi_n + 9));
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}
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void spi_free(spi_t *obj)
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{
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}
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void spi_format(spi_t *obj, int bits, int mode, int slave)
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{
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spi_disable(obj);
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MBED_ASSERT((bits >= 1 && bits <= 16) && (mode >= 0 && mode <= 3));
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int polarity = (mode & 0x2) ? 1 : 0;
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int phase = (mode & 0x1) ? 1 : 0;
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// set it up
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int LEN = bits - 1; // LEN - Data Length
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int CPOL = (polarity) ? 1 : 0; // CPOL - Clock Polarity select
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int CPHA = (phase) ? 1 : 0; // CPHA - Clock Phase select
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uint32_t tmp = obj->spi->CFG;
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tmp &= ~((1 << 5) | (1 << 4) | (1 << 2));
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tmp |= (CPOL << 5) | (CPHA << 4) | ((slave ? 0 : 1) << 2);
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obj->spi->CFG = tmp;
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// select frame length
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tmp = obj->spi->TXCTL;
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tmp &= ~(0xf << 24);
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tmp |= (LEN << 24);
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obj->spi->TXCTL = tmp;
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spi_enable(obj);
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}
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void spi_frequency(spi_t *obj, int hz)
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{
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spi_disable(obj);
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// rise DIV value if it cannot be divided
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obj->spi->DIV = (SystemCoreClock + (hz - 1))/hz - 1;
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obj->spi->DLY = 0;
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spi_enable(obj);
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}
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static inline void spi_disable(spi_t *obj)
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{
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obj->spi->CFG &= ~(1 << 0);
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}
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static inline void spi_enable(spi_t *obj)
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{
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obj->spi->CFG |= (1 << 0);
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}
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static inline int spi_readable(spi_t *obj)
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{
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return obj->spi->STAT & (1 << 0);
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}
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static inline int spi_writeable(spi_t *obj)
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{
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return obj->spi->STAT & (1 << 1);
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}
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static inline void spi_write(spi_t *obj, int value)
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{
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while (!spi_writeable(obj));
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// end of transfer
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obj->spi->TXCTL |= (1 << 20);
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obj->spi->TXDAT = (value & 0xffff);
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}
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static inline int spi_read(spi_t *obj)
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{
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while (!spi_readable(obj));
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return obj->spi->RXDAT & 0xffff; // Only the lower 16 bits contain data
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}
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int spi_busy(spi_t *obj)
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{
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// checking RXOV(Receiver Overrun interrupt flag)
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return obj->spi->STAT & (1 << 2);
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}
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int spi_master_write(spi_t *obj, int value)
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{
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spi_write(obj, value);
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return spi_read(obj);
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}
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int spi_master_block_write(spi_t *obj, const char *tx_buffer,
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int tx_length, char *rx_buffer, int rx_length, char write_fill) {
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int total = (tx_length > rx_length) ? tx_length : rx_length;
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for (int i = 0; i < total; i++) {
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char out = (i < tx_length) ? tx_buffer[i] : write_fill;
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char in = spi_master_write(obj, out);
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if (i < rx_length) {
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rx_buffer[i] = in;
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}
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}
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return total;
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}
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int spi_slave_receive(spi_t *obj)
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{
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return (spi_readable(obj) && !spi_busy(obj)) ? (1) : (0);
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}
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int spi_slave_read(spi_t *obj)
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{
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return obj->spi->RXDAT & 0xffff; // Only the lower 16 bits contain data
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}
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void spi_slave_write(spi_t *obj, int value)
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{
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while (spi_writeable(obj) == 0) ;
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obj->spi->TXDAT = value;
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}
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const PinMap *spi_master_mosi_pinmap()
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{
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return PinMap_SPI_testing;
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}
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const PinMap *spi_master_miso_pinmap()
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{
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return PinMap_SPI_testing;
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}
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const PinMap *spi_master_clk_pinmap()
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{
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return PinMap_SPI_testing;
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}
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const PinMap *spi_master_cs_pinmap()
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{
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return PinMap_SPI_testing;
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}
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const PinMap *spi_slave_mosi_pinmap()
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{
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return PinMap_SPI_testing;
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}
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const PinMap *spi_slave_miso_pinmap()
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{
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return PinMap_SPI_testing;
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}
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const PinMap *spi_slave_clk_pinmap()
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{
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return PinMap_SPI_testing;
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}
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const PinMap *spi_slave_cs_pinmap()
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{
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return PinMap_SPI_testing;
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}
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