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