Diff: targets/hal/TARGET_Silicon_Labs/TARGET_EFM32/analogout_api.c

Revision:

0:9b334a45a8ff

Child:

50:a417edff4437

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/targets/hal/TARGET_Silicon_Labs/TARGET_EFM32/analogout_api.c	Thu Oct 01 15:25:22 2015 +0300
@@ -0,0 +1,155 @@
+/***************************************************************************//**
+ * @file analogout_aoi.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_ANALOGOUT
+
+#include "mbed_assert.h"
+#include "error.h"
+#include "analogout_api.h"
+#include "pinmap.h"
+#include "pinmap_function.h"
+#include "PeripheralPins.h"
+#include "clocking.h"
+
+#include "em_dac.h"
+#include "em_cmu.h"
+
+uint8_t analogout_get_index(dac_t *obj)
+{
+    return 0;
+}
+
+void analogout_preinit(dac_t *obj, PinName pin)
+{
+    obj->dac = (DAC_TypeDef *) pinmap_peripheral(pin, PinMap_DAC);
+    MBED_ASSERT((int) obj->dac != NC);
+
+    obj->channel = pin_location(pin, PinMap_DAC);
+    MBED_ASSERT((int) obj->channel != NC);
+}
+
+void analogout_init(dac_t *obj, PinName pin)
+{
+    static uint8_t dac_initialized = 0;
+
+    /* init in-memory structure */
+    analogout_preinit(obj, pin);
+
+    if (!dac_initialized) {
+        /* Initialize the DAC. Will disable both DAC channels, so should only be done once */
+        /* Use default settings */
+        CMU_ClockEnable(cmuClock_DAC0, true);
+
+        DAC_Init_TypeDef init = DAC_INIT_DEFAULT;
+
+        /* Calculate the DAC clock prescaler value that will result in a DAC clock
+         * close to 500kHz. Second parameter is zero. This uses the current HFPERCLK
+         * frequency instead of setting a new one. */
+        init.prescale = DAC_PrescaleCalc(500000, REFERENCE_FREQUENCY);
+
+        /* Set reference voltage to VDD */
+        init.reference = dacRefVDD;
+
+        DAC_Init(obj->dac, &init);
+        dac_initialized = 1;
+    }
+    /* Use default channel settings */
+    DAC_InitChannel_TypeDef initChannel = DAC_INITCHANNEL_DEFAULT;
+    DAC_InitChannel(obj->dac, &initChannel, obj->channel);
+
+
+}
+
+void analogout_enable(dac_t *obj, uint8_t enable)
+{
+    DAC_Enable(obj->dac, obj->channel, enable);
+}
+
+void analogout_pins_enable(dac_t *obj, uint8_t enable)
+{
+    //not avail for EFM32
+}
+
+static inline void dac_write(dac_t *obj, int value)
+{
+    switch (obj->channel) {
+        case 0:
+            obj->dac->CH0DATA = value;
+            break;
+        case 1:
+            obj->dac->CH1DATA = value;
+            break;
+    }
+}
+
+static inline int dac_read(dac_t *obj)
+{
+    switch (obj->channel) {
+        case 0:
+            return obj->dac->CH0DATA;
+            break;
+        case 1:
+            return obj->dac->CH1DATA;
+            break;
+        default:
+            error("AnalogOut pin error. Invalid channel");
+            return -1;
+            break;
+    }
+}
+
+void analogout_write(dac_t *obj, float value)
+{
+    /* We multiply the float value with 0xFFF because the DAC has 12-bit resolution.
+     * Ie. accepts values between 0 and 0xFFF (4096). */
+    dac_write(obj, value*0xFFF);
+}
+
+void analogout_write_u16(dac_t *obj, uint16_t value)
+{
+    /* The DAC has 12 bit resolution, so we remove the 4 least significant bits */
+    dac_write(obj, value >> 4);
+}
+
+float analogout_read(dac_t *obj)
+{
+    /* dac_read returns a number between 0 and 0xFFF. Division gives us a float between 0 and 1 */
+    return dac_read(obj)/(float)0xFFF;
+}
+
+uint16_t analogout_read_u16(dac_t *obj)
+{
+    /* dac_read returns a number with 12 significant digits,
+     * so we shift in 0s from right to make it a 16 bit number */
+    return dac_read(obj) << 4;
+}
+
+#endif