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Diff: targets/hal/TARGET_Silicon_Labs/TARGET_EFM32/analogin_api.c
- Revision:
- 0:9b334a45a8ff
- Child:
- 50:a417edff4437
diff -r 000000000000 -r 9b334a45a8ff targets/hal/TARGET_Silicon_Labs/TARGET_EFM32/analogin_api.c --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/targets/hal/TARGET_Silicon_Labs/TARGET_EFM32/analogin_api.c Thu Oct 01 15:25:22 2015 +0300 @@ -0,0 +1,144 @@ +/***************************************************************************//** + * @file analogin_api.c + ******************************************************************************* + * @section License + * <b>(C) Copyright 2015 Silicon Labs, http://www.silabs.com</b> + ******************************************************************************* + * + * Permission is granted to anyone to use this software for any purpose, + * including commercial applications, and to alter it and redistribute it + * freely, subject to the following restrictions: + * + * 1. The origin of this software must not be misrepresented; you must not + * claim that you wrote the original software. + * 2. Altered source versions must be plainly marked as such, and must not be + * misrepresented as being the original software. + * 3. This notice may not be removed or altered from any source distribution. + * + * DISCLAIMER OF WARRANTY/LIMITATION OF REMEDIES: Silicon Labs has no + * obligation to support this Software. Silicon Labs is providing the + * Software "AS IS", with no express or implied warranties of any kind, + * including, but not limited to, any implied warranties of merchantability + * or fitness for any particular purpose or warranties against infringement + * of any proprietary rights of a third party. + * + * Silicon Labs will not be liable for any consequential, incidental, or + * special damages, or any other relief, or for any claim by any third party, + * arising from your use of this Software. + * + ******************************************************************************/ + +#include "device.h" +#if DEVICE_ANALOGIN + +#include "mbed_assert.h" +#include "analogin_api.h" + +#include "pinmap.h" +#include "pinmap_function.h" +#include "PeripheralPins.h" + +#include "em_adc.h" +#include "em_cmu.h" + +uint8_t analogin_get_index(analogin_t *obj) +{ + return 0; //only one module availalbe +} + +void analogin_preinit(analogin_t *obj, PinName pin) +{ + obj->adc = (ADC_TypeDef *) pinmap_peripheral(pin, PinMap_ADC); + MBED_ASSERT((int) obj->adc != NC); + + obj->channel = pin_location(pin, PinMap_ADC); + MBED_ASSERT((int) obj->channel != NC); +} + +void analogin_init(analogin_t *obj, PinName pin) +{ + static uint8_t adc_initialized = 0; + + /* Init structure */ + analogin_preinit(obj, pin); + + /* Only initialize the ADC once */ + if (!adc_initialized) { + /* Turn on the clock */ + CMU_ClockEnable(cmuClock_ADC0, true); + + /* Init with default settings */ + ADC_Init_TypeDef init = ADC_INIT_DEFAULT; + init.prescale = 4; + ADC_Init(obj->adc, &init); + + /* Init for single conversion use */ + ADC_InitSingle_TypeDef singleInit = ADC_INITSINGLE_DEFAULT; + + /* Measure input channel with Vdd reference. */ + singleInit.reference = adcRefVDD; + singleInit.resolution = adcRes12Bit; + singleInit.acqTime = adcAcqTime32; + + ADC_InitSingle(obj->adc, &singleInit); + + adc_initialized = 1; + } +} + +void analogin_enable(analogin_t *obj, uint8_t enable) +{ + //not avail for EFM32 +} + +void analogin_enable_pins(analogin_t *obj, uint8_t enable) +{ + //not avail for EFM32 +} + +void analogin_enable_interrupt(analogin_t *obj, uint32_t address, uint8_t enable) +{ + NVIC_SetVector(ADC0_IRQn, address); + if (enable) { + // enable end of conversion interrupt + ADC_IntEnable(obj->adc, ADC_IEN_SCAN); + ADC_IntSet(obj->adc, ADC_IF_SCAN); + NVIC_EnableIRQ(ADC0_IRQn); + } else { + ADC_IntDisable(obj->adc, ADC_IEN_SCAN); + ADC_IntClear(obj->adc, ADC_IF_SCAN); + NVIC_DisableIRQ(ADC0_IRQn); + } +} + +uint16_t analogin_read_u16(analogin_t *obj) +{ + ADC_TypeDef *adc = obj->adc; + uint16_t sample = 0; + + //Make sure a single conversion is not in progress + adc->CMD = ADC_CMD_SINGLESTOP; + + // Make sure we are checking the correct channel + adc->SINGLECTRL = (adc->SINGLECTRL & ~_ADC_SINGLECTRL_INPUTSEL_MASK) | obj->channel; + + ADC_Start(adc, adcStartSingle); + + /* Wait while conversion is active */ + while (adc->STATUS & ADC_STATUS_SINGLEACT); + + /* Get ADC result */ + sample = ADC_DataSingleGet(adc); + + /* The ADC has 12 bit resolution. We shift in 4 0s */ + /* from the right to make it a 16 bit number as expected */ + return sample << 4; +} + +float analogin_read(analogin_t *obj) +{ + /* Convert from a uint16 to a float between 0 and 1 by division by 0xFFFF */ + return analogin_read_u16(obj) / (float) 0xFFFF; +} + +#endif