mbed library sources
Dependents: frdm_kl05z_gpio_test
Fork of mbed-src by
vendor/NXP/LPC812/hal/spi_api.c
- Committer:
- emilmont
- Date:
- 2013-06-14
- Revision:
- 10:3bc89ef62ce7
File content as of revision 10:3bc89ef62ce7:
/* mbed Microcontroller Library * Copyright (c) 2006-2013 ARM Limited * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #include <math.h> #include "spi_api.h" #include "cmsis.h" #include "pinmap.h" #include "error.h" static const SWM_Map SWM_SPI_SSEL[] = { {4, 16}, {5, 16}, }; static const SWM_Map SWM_SPI_SCLK[] = { {3, 24}, {4, 24}, }; static const SWM_Map SWM_SPI_MOSI[] = { {4, 0}, {5, 0}, }; static const SWM_Map SWM_SPI_MISO[] = { {4, 8}, {5, 16}, }; // bit flags for used SPIs static unsigned char spi_used = 0; static int get_available_spi(void) { int i; for (i=0; i<2; i++) { if ((spi_used & (1 << i)) == 0) return i; } return -1; } static inline int ssp_disable(spi_t *obj); static inline int ssp_enable(spi_t *obj); void spi_init(spi_t *obj, PinName mosi, PinName miso, PinName sclk, PinName ssel) { int spi_n = get_available_spi(); if (spi_n == -1) { error("No available SPI"); } obj->spi_n = spi_n; spi_used |= (1 << spi_n); obj->spi = (spi_n) ? (LPC_SPI_TypeDef *)(LPC_SPI1_BASE) : (LPC_SPI_TypeDef *)(LPC_SPI0_BASE); const SWM_Map *swm; uint32_t regVal; swm = &SWM_SPI_SCLK[obj->spi_n]; regVal = LPC_SWM->PINASSIGN[swm->n] & ~(0xFF << swm->offset); LPC_SWM->PINASSIGN[swm->n] = regVal | (sclk << swm->offset); swm = &SWM_SPI_MOSI[obj->spi_n]; regVal = LPC_SWM->PINASSIGN[swm->n] & ~(0xFF << swm->offset); LPC_SWM->PINASSIGN[swm->n] = regVal | (mosi << swm->offset); swm = &SWM_SPI_MISO[obj->spi_n]; regVal = LPC_SWM->PINASSIGN[swm->n] & ~(0xFF << swm->offset); LPC_SWM->PINASSIGN[swm->n] = regVal | (miso << swm->offset); swm = &SWM_SPI_SSEL[obj->spi_n]; regVal = LPC_SWM->PINASSIGN[swm->n] & ~(0xFF << swm->offset); LPC_SWM->PINASSIGN[swm->n] = regVal | (ssel << swm->offset); // clear interrupts obj->spi->INTENCLR = 0x3f; // enable power and clocking switch (obj->spi_n) { case 0: LPC_SYSCON->SYSAHBCLKCTRL |= (1<<11); LPC_SYSCON->PRESETCTRL &= ~(0x1<<0); LPC_SYSCON->PRESETCTRL |= (0x1<<0); break; case 1: LPC_SYSCON->SYSAHBCLKCTRL |= (1<<12); LPC_SYSCON->PRESETCTRL &= ~(0x1<<1); LPC_SYSCON->PRESETCTRL |= (0x1<<1); break; } // set default format and frequency if (ssel == NC) { spi_format(obj, 8, 0, 0); // 8 bits, mode 0, master } else { spi_format(obj, 8, 0, 1); // 8 bits, mode 0, slave } spi_frequency(obj, 1000000); // enable the ssp channel ssp_enable(obj); } void spi_free(spi_t *obj) {} void spi_format(spi_t *obj, int bits, int mode, int slave) { ssp_disable(obj); if (!(bits >= 1 && bits <= 16) || !(mode >= 0 && mode <= 3)) { error("SPI format error"); } int polarity = (mode & 0x2) ? 1 : 0; int phase = (mode & 0x1) ? 1 : 0; // set it up int DSS = bits - 1; // DSS (data select size) int SPO = (polarity) ? 1 : 0; // SPO - clock out polarity int SPH = (phase) ? 1 : 0; // SPH - clock out phase uint32_t tmp = obj->spi->CFG; tmp &= ~((1 << 2) | (1 << 4) | (1 << 5)); tmp |= (SPH << 4) | (SPO << 5) | ((slave ? 0 : 1) << 2); obj->spi->CFG = tmp; // select frame length tmp = obj->spi->TXDATCTL; tmp &= ~(0xf << 24); tmp |= (DSS << 24); obj->spi->TXDATCTL = tmp; ssp_enable(obj); } void spi_frequency(spi_t *obj, int hz) { ssp_disable(obj); uint32_t PCLK = SystemCoreClock; obj->spi->DIV = PCLK/hz - 1; obj->spi->DLY = 0; ssp_enable(obj); } static inline int ssp_disable(spi_t *obj) { return obj->spi->CFG &= ~(1 << 0); } static inline int ssp_enable(spi_t *obj) { return obj->spi->CFG |= (1 << 0); } static inline int ssp_readable(spi_t *obj) { return obj->spi->STAT & (1 << 0); } static inline int ssp_writeable(spi_t *obj) { return obj->spi->STAT & (1 << 1); } static inline void ssp_write(spi_t *obj, int value) { while (!ssp_writeable(obj)); // end of transfer obj->spi->TXDATCTL |= (1 << 20); obj->spi->TXDAT = value; } static inline int ssp_read(spi_t *obj) { while (!ssp_readable(obj)); return obj->spi->RXDAT; } static inline int ssp_busy(spi_t *obj) { // TODO return 0; } int spi_master_write(spi_t *obj, int value) { ssp_write(obj, value); return ssp_read(obj); } int spi_slave_receive(spi_t *obj) { return (ssp_readable(obj) && !ssp_busy(obj)) ? (1) : (0); }; int spi_slave_read(spi_t *obj) { return obj->spi->RXDAT; } void spi_slave_write(spi_t *obj, int value) { while (ssp_writeable(obj) == 0) ; obj->spi->TXDAT = value; } int spi_busy(spi_t *obj) { return ssp_busy(obj); }