diff options
Diffstat (limited to 'tmk_core/tool/mbed/mbed-sdk/libraries/mbed/targets/hal/TARGET_NXP/TARGET_LPC11UXX/spi_api.c')
| -rw-r--r-- | tmk_core/tool/mbed/mbed-sdk/libraries/mbed/targets/hal/TARGET_NXP/TARGET_LPC11UXX/spi_api.c | 185 |
1 files changed, 185 insertions, 0 deletions
diff --git a/tmk_core/tool/mbed/mbed-sdk/libraries/mbed/targets/hal/TARGET_NXP/TARGET_LPC11UXX/spi_api.c b/tmk_core/tool/mbed/mbed-sdk/libraries/mbed/targets/hal/TARGET_NXP/TARGET_LPC11UXX/spi_api.c new file mode 100644 index 0000000000..594f1f086b --- /dev/null +++ b/tmk_core/tool/mbed/mbed-sdk/libraries/mbed/targets/hal/TARGET_NXP/TARGET_LPC11UXX/spi_api.c @@ -0,0 +1,185 @@ +/* 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 "mbed_assert.h" +#include <math.h> +#include "spi_api.h" +#include "cmsis.h" +#include "pinmap.h" +#include "mbed_error.h" +#include "PeripheralPins.h" // For the Peripheral to Pin Definitions found in the individual Target's Platform + +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) { + // determine the SPI to use + SPIName spi_mosi = (SPIName)pinmap_peripheral(mosi, PinMap_SPI_MOSI); + SPIName spi_miso = (SPIName)pinmap_peripheral(miso, PinMap_SPI_MISO); + SPIName spi_sclk = (SPIName)pinmap_peripheral(sclk, PinMap_SPI_SCLK); + SPIName spi_ssel = (SPIName)pinmap_peripheral(ssel, PinMap_SPI_SSEL); + SPIName spi_data = (SPIName)pinmap_merge(spi_mosi, spi_miso); + SPIName spi_cntl = (SPIName)pinmap_merge(spi_sclk, spi_ssel); + + obj->spi = (LPC_SSPx_Type*)pinmap_merge(spi_data, spi_cntl); + MBED_ASSERT((int)obj->spi != NC); + + // enable power and clocking + switch ((int)obj->spi) { + case SPI_0: + LPC_SYSCON->SYSAHBCLKCTRL |= 1 << 11; + LPC_SYSCON->SSP0CLKDIV = 0x01; + LPC_SYSCON->PRESETCTRL |= 1 << 0; + break; + case SPI_1: + LPC_SYSCON->SYSAHBCLKCTRL |= 1 << 18; + LPC_SYSCON->SSP1CLKDIV = 0x01; + LPC_SYSCON->PRESETCTRL |= 1 << 2; + 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); + + // pin out the spi pins + pinmap_pinout(mosi, PinMap_SPI_MOSI); + pinmap_pinout(miso, PinMap_SPI_MISO); + pinmap_pinout(sclk, PinMap_SPI_SCLK); + if (ssel != NC) { + pinmap_pinout(ssel, PinMap_SPI_SSEL); + } +} + +void spi_free(spi_t *obj) {} + +void spi_format(spi_t *obj, int bits, int mode, int slave) { + MBED_ASSERT((bits >= 4 && bits <= 16) || (mode >= 0 && mode <= 3)); + + ssp_disable(obj); + + 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 + + int FRF = 0; // FRF (frame format) = SPI + uint32_t tmp = obj->spi->CR0; + tmp &= ~(0xFFFF); + tmp |= DSS << 0 + | FRF << 4 + | SPO << 6 + | SPH << 7; + obj->spi->CR0 = tmp; + + tmp = obj->spi->CR1; + tmp &= ~(0xD); + tmp |= 0 << 0 // LBM - loop back mode - off + | ((slave) ? 1 : 0) << 2 // MS - master slave mode, 1 = slave + | 0 << 3; // SOD - slave output disable - na + obj->spi->CR1 = tmp; + + ssp_enable(obj); +} + +void spi_frequency(spi_t *obj, int hz) { + ssp_disable(obj); + + uint32_t PCLK = SystemCoreClock; + + int prescaler; + + for (prescaler = 2; prescaler <= 254; prescaler += 2) { + int prescale_hz = PCLK / prescaler; + + // calculate the divider + int divider = floor(((float)prescale_hz / (float)hz) + 0.5f); + + // check we can support the divider + if (divider < 256) { + // prescaler + obj->spi->CPSR = prescaler; + + // divider + obj->spi->CR0 &= ~(0xFFFF << 8); + obj->spi->CR0 |= (divider - 1) << 8; + ssp_enable(obj); + return; + } + } + error("Couldn't setup requested SPI frequency"); +} + +static inline int ssp_disable(spi_t *obj) { + return obj->spi->CR1 &= ~(1 << 1); +} + +static inline int ssp_enable(spi_t *obj) { + return obj->spi->CR1 |= (1 << 1); +} + +static inline int ssp_readable(spi_t *obj) { + return obj->spi->SR & (1 << 2); +} + +static inline int ssp_writeable(spi_t *obj) { + return obj->spi->SR & (1 << 1); +} + +static inline void ssp_write(spi_t *obj, int value) { + while (!ssp_writeable(obj)); + obj->spi->DR = value; +} + +static inline int ssp_read(spi_t *obj) { + while (!ssp_readable(obj)); + return obj->spi->DR; +} + +static inline int ssp_busy(spi_t *obj) { + return (obj->spi->SR & (1 << 4)) ? (1) : (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->DR; +} + +void spi_slave_write(spi_t *obj, int value) { + while (ssp_writeable(obj) == 0) ; + obj->spi->DR = value; +} + +int spi_busy(spi_t *obj) { + return ssp_busy(obj); +} |