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Diff: targets/TARGET_STM/TARGET_STM32L0/analogout_api.c
- Revision:
- 149:156823d33999
- Parent:
- 144:ef7eb2e8f9f7
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/targets/TARGET_STM/TARGET_STM32L0/analogout_api.c Fri Oct 28 11:17:30 2016 +0100 @@ -0,0 +1,158 @@ +/* mbed Microcontroller Library + * Copyright (c) 2015, STMicroelectronics + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are met: + * + * 1. Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright notice, + * this list of conditions and the following disclaimer in the documentation + * and/or other materials provided with the distribution. + * 3. Neither the name of STMicroelectronics nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE + * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR + * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER + * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, + * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ +#include "mbed_assert.h" +#include "analogout_api.h" + +#if DEVICE_ANALOGOUT + +#include "cmsis.h" +#include "pinmap.h" +#include "mbed_error.h" +#include "PeripheralPins.h" + +#define DAC_RANGE (0xFFF) // 12 bits +#define DAC_NB_BITS (12) + +static DAC_HandleTypeDef DacHandle; + +// These variables are used for the "free" function +static int channel1_used = 0; +static int channel2_used = 0; + +void analogout_init(dac_t *obj, PinName pin) { + DAC_ChannelConfTypeDef sConfig; + + // Get the peripheral name from the pin and assign it to the object + obj->dac = (DACName)pinmap_peripheral(pin, PinMap_DAC); + MBED_ASSERT(obj->dac != (DACName)NC); + + // Get the pin function and assign the used channel to the object + uint32_t function = pinmap_function(pin, PinMap_DAC); + MBED_ASSERT(function != (uint32_t)NC); + obj->channel = STM_PIN_CHANNEL(function); + + // Configure GPIO + pinmap_pinout(pin, PinMap_DAC); + + // Save the pin for future use + obj->pin = pin; + + // Enable DAC clock + __DAC_CLK_ENABLE(); + + // Configure DAC + DacHandle.Instance = DAC; + + sConfig.DAC_Trigger = DAC_TRIGGER_NONE; + sConfig.DAC_OutputBuffer = DAC_OUTPUTBUFFER_DISABLE; + +#if defined(DAC_CHANNEL_2) + if (obj->channel == 2) { + if (HAL_DAC_ConfigChannel(&DacHandle, &sConfig, DAC_CHANNEL_2) != HAL_OK) { + error("Cannot configure DAC channel 2"); + } + channel2_used = 1; + } else +#endif + { + // channel 1 per default + if (HAL_DAC_ConfigChannel(&DacHandle, &sConfig, DAC_CHANNEL_1) != HAL_OK) { + error("Cannot configure DAC channel 1"); + } + obj->channel = 1; + channel1_used = 1; + } + + analogout_write_u16(obj, 0); +} + +void analogout_free(dac_t *obj) { + // Reset DAC and disable clock + if (obj->channel == 1) channel1_used = 0; + if (obj->channel == 2) channel2_used = 0; + + if ((channel1_used == 0) && (channel2_used == 0)) { + __DAC_FORCE_RESET(); + __DAC_RELEASE_RESET(); + __DAC_CLK_DISABLE(); + } + + // Configure GPIO + pin_function(obj->pin, STM_PIN_DATA(STM_MODE_INPUT, GPIO_NOPULL, 0)); +} + +static inline void dac_write(dac_t *obj, int value) { + if (obj->channel == 1) { + HAL_DAC_SetValue(&DacHandle, DAC_CHANNEL_1, DAC_ALIGN_12B_R, (value & DAC_RANGE)); + HAL_DAC_Start(&DacHandle, DAC_CHANNEL_1); + } +#if defined(DAC_CHANNEL_2) + if (obj->channel == 2) { + HAL_DAC_SetValue(&DacHandle, DAC_CHANNEL_2, DAC_ALIGN_12B_R, (value & DAC_RANGE)); + HAL_DAC_Start(&DacHandle, DAC_CHANNEL_2); + } +#endif +} + +static inline int dac_read(dac_t *obj) { + if (obj->channel == 1) { + return (int)HAL_DAC_GetValue(&DacHandle, DAC_CHANNEL_1); + } +#if defined(DAC_CHANNEL_2) + if (obj->channel == 2) { + return (int)HAL_DAC_GetValue(&DacHandle, DAC_CHANNEL_2); + } +#endif + return 0; +} + +void analogout_write(dac_t *obj, float value) { + if (value < 0.0f) { + dac_write(obj, 0); // Min value + } else if (value > 1.0f) { + dac_write(obj, (int)DAC_RANGE); // Max value + } else { + dac_write(obj, (int)(value * (float)DAC_RANGE)); + } +} + +void analogout_write_u16(dac_t *obj, uint16_t value) { + dac_write(obj, value >> (16 - DAC_NB_BITS)); +} + +float analogout_read(dac_t *obj) { + uint32_t value = dac_read(obj); + return (float)value * (1.0f / (float)DAC_RANGE); +} + +uint16_t analogout_read_u16(dac_t *obj) { + uint32_t value = dac_read(obj); + return (value << 4) | ((value >> 8) & 0x000F); // Conversion from 12 to 16 bits +} + +#endif // DEVICE_ANALOGOUT