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stm: Add DMA support to Audio object.

pull/335/head
Damien George 11 years ago
parent
2da9830b92
commit
5322ec0962
1 changed files with 161 additions and 53 deletions
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  1. 214
      stm/audio.c

214
stm/audio.c
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@ -1,8 +1,6 @@
#include <stdint.h>
#include <string.h>
#include "stm32f4xx_rcc.h"
#include "stm32f4xx_gpio.h"
#include "stm32f4xx_dac.h"
#include "nlr.h"
@ -11,38 +9,34 @@
#include "qstr.h"
#include "parse.h"
#include "obj.h"
#include "map.h"
#include "runtime.h"
#include "audio.h"
#define SAMPLE_BUF_SIZE (32)
STATIC void TIM7_Config(uint freq) {
// TIM7 clock enable
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM7, ENABLE);
// sample_buf_in is always the same or ahead of sample_buf_out
// when they are the same, there are no more samples left to process
// in this scheme, there is always 1 unusable byte in the buffer, just before sample_buf_out
int sample_buf_in;
int sample_buf_out;
byte sample_buf[SAMPLE_BUF_SIZE];
// reset TIM7
TIM_DeInit(TIM7);
bool audio_is_full(void) {
return ((sample_buf_in + 1) % SAMPLE_BUF_SIZE) == sample_buf_out;
}
// Compute the prescaler value so TIM7 triggers at freq-Hz
uint16_t period = (uint16_t) ((SystemCoreClock / 2) / freq) - 1;
void audio_fill(byte sample) {
sample_buf[sample_buf_in] = sample;
sample_buf_in = (sample_buf_in + 1) % SAMPLE_BUF_SIZE;
// enable interrupt
}
// Time base configuration
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
TIM_TimeBaseStructure.TIM_Period = period; // timer triggers with this period
TIM_TimeBaseStructure.TIM_Prescaler = 0; // timer runs at SystemCoreClock / 2
TIM_TimeBaseStructure.TIM_ClockDivision = 0; // unused for TIM7
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up; // unused for TIM7
TIM_TimeBaseInit(TIM7, &TIM_TimeBaseStructure);
void audio_drain(void) {
if (sample_buf_in == sample_buf_out) {
// buffer is empty; disable interrupt
} else {
// buffer has a sample; output it
byte sample = sample_buf[sample_buf_out];
DAC_SetChannel2Data(DAC_Align_8b_R, sample);
sample_buf_out = (sample_buf_out + 1) % SAMPLE_BUF_SIZE;
}
// TIM7 TRGO selection
TIM_SelectOutputTrigger(TIM7, TIM_TRGOSource_Update);
// TIM7 enable counter
TIM_Cmd(TIM7, ENABLE);
}
/******************************************************************************/
@ -50,13 +44,67 @@ void audio_drain(void) {
typedef struct _pyb_audio_t {
mp_obj_base_t base;
int dac_id; // 1 or 2
uint dac_channel; // DAC_Channel_1 or DAC_Channel_2
DMA_Stream_TypeDef *dma_stream; // DMA1_Stream6 or DMA1_Stream7
} pyb_audio_t;
mp_obj_t pyb_audio_noise(mp_obj_t self_in, mp_obj_t freq) {
pyb_audio_t *self = self_in;
// set TIM7 to trigger the DAC at the given frequency
TIM7_Config(mp_obj_get_int(freq));
DAC_Cmd(self->dac_channel, DISABLE);
DAC_InitTypeDef DAC_InitStructure;
DAC_InitStructure.DAC_Trigger = DAC_Trigger_T7_TRGO;
DAC_InitStructure.DAC_WaveGeneration = DAC_WaveGeneration_Noise;
DAC_InitStructure.DAC_LFSRUnmask_TriangleAmplitude = DAC_LFSRUnmask_Bits10_0;
DAC_InitStructure.DAC_OutputBuffer = DAC_OutputBuffer_Enable;
DAC_Init(self->dac_channel, &DAC_InitStructure);
DAC_Cmd(self->dac_channel, ENABLE);
if (self->dac_channel == DAC_Channel_1) {
DAC_SetChannel1Data(DAC_Align_12b_L, 0x7ff0);
} else {
DAC_SetChannel2Data(DAC_Align_12b_L, 0x7ff0);
}
return mp_const_none;
}
mp_obj_t pyb_audio_triangle(mp_obj_t self_in, mp_obj_t freq) {
pyb_audio_t *self = self_in;
// set TIM7 to trigger the DAC at the given frequency
TIM7_Config(mp_obj_get_int(freq));
DAC_Cmd(self->dac_channel, DISABLE);
DAC_InitTypeDef DAC_InitStructure;
DAC_InitStructure.DAC_Trigger = DAC_Trigger_T7_TRGO;
DAC_InitStructure.DAC_WaveGeneration = DAC_WaveGeneration_Triangle;
DAC_InitStructure.DAC_LFSRUnmask_TriangleAmplitude = DAC_TriangleAmplitude_1023;
DAC_InitStructure.DAC_OutputBuffer = DAC_OutputBuffer_Enable;
DAC_Init(self->dac_channel, &DAC_InitStructure);
DAC_Cmd(self->dac_channel, ENABLE);
// set base value of triangle wave
if (self->dac_channel == DAC_Channel_1) {
DAC_SetChannel1Data(DAC_Align_12b_R, 0x100);
} else {
DAC_SetChannel2Data(DAC_Align_12b_R, 0x100);
}
return mp_const_none;
}
// direct access to DAC
mp_obj_t pyb_audio_dac(mp_obj_t self_in, mp_obj_t val) {
pyb_audio_t *self = self_in;
if (self->dac_id == 1) {
if (self->dac_channel == DAC_Channel_1) {
DAC_SetChannel1Data(DAC_Align_8b_R, mp_obj_get_int(val));
} else {
DAC_SetChannel2Data(DAC_Align_8b_R, mp_obj_get_int(val));
@ -64,27 +112,92 @@ mp_obj_t pyb_audio_dac(mp_obj_t self_in, mp_obj_t val) {
return mp_const_none;
}
mp_obj_t pyb_audio_is_full(mp_obj_t self_in) {
if (audio_is_full()) {
return mp_const_true;
#define DAC_DHR8R1_ADDRESS (DAC_BASE + 0x10)
#define DAC_DHR8R2_ADDRESS (DAC_BASE + 0x1c)
// initiates a burst of RAM->DAC using DMA
// input data is treated as an array of bytes (8 bit data)
// TIM7 is used to set the frequency of the transfer
mp_obj_t pyb_audio_dma(uint n_args, const mp_obj_t *args, mp_map_t *kw_args) {
pyb_audio_t *self = args[0];
// set TIM7 to trigger the DAC at the given frequency
TIM7_Config(mp_obj_get_int(args[2]));
mp_obj_type_t *type = mp_obj_get_type(args[1]);
if (type->buffer_p.get_buffer == NULL) {
nlr_jump(mp_obj_new_exception_msg(&mp_type_TypeError, "buffer argument must support buffer protocol"));
}
buffer_info_t bufinfo;
type->buffer_p.get_buffer(args[1], &bufinfo, BUFFER_READ);
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_DMA1, ENABLE);
DMA_Cmd(self->dma_stream, DISABLE);
while (DMA_GetCmdStatus(self->dma_stream) != DISABLE) {
}
DAC_Cmd(self->dac_channel, DISABLE);
// DAC channel configuration
DAC_InitTypeDef DAC_InitStructure;
DAC_InitStructure.DAC_Trigger = DAC_Trigger_T7_TRGO;
DAC_InitStructure.DAC_WaveGeneration = DAC_WaveGeneration_None;
DAC_InitStructure.DAC_LFSRUnmask_TriangleAmplitude = DAC_TriangleAmplitude_1; // unused, but need to set it to a valid value
DAC_InitStructure.DAC_OutputBuffer = DAC_OutputBuffer_Enable;
DAC_Init(self->dac_channel, &DAC_InitStructure);
// DMA1_Stream[67] channel7 configuration
DMA_DeInit(self->dma_stream);
DMA_InitTypeDef DMA_InitStructure;
DMA_InitStructure.DMA_Channel = DMA_Channel_7;
if (self->dac_channel == DAC_Channel_1) {
DMA_InitStructure.DMA_PeripheralBaseAddr = DAC_DHR8R1_ADDRESS;
} else {
return mp_const_false;
DMA_InitStructure.DMA_PeripheralBaseAddr = DAC_DHR8R2_ADDRESS;
}
}
DMA_InitStructure.DMA_Memory0BaseAddr = (uint32_t)bufinfo.buf;
DMA_InitStructure.DMA_DIR = DMA_DIR_MemoryToPeripheral;
DMA_InitStructure.DMA_BufferSize = bufinfo.len;
DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;
DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;
DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Byte;
DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_Byte;
mp_map_elem_t *kw_mode = mp_map_lookup(kw_args, MP_OBJ_NEW_QSTR(qstr_from_str("mode")), MP_MAP_LOOKUP);
DMA_InitStructure.DMA_Mode = kw_mode == NULL ? DMA_Mode_Normal : mp_obj_get_int(kw_mode->value); // normal = 0, circular = 0x100
DMA_InitStructure.DMA_Priority = DMA_Priority_High;
DMA_InitStructure.DMA_FIFOMode = DMA_FIFOMode_Disable;
DMA_InitStructure.DMA_FIFOThreshold = DMA_FIFOThreshold_HalfFull;
DMA_InitStructure.DMA_MemoryBurst = DMA_MemoryBurst_Single;
DMA_InitStructure.DMA_PeripheralBurst = DMA_PeripheralBurst_Single;
DMA_Init(self->dma_stream, &DMA_InitStructure);
// enable DMA stream
DMA_Cmd(self->dma_stream, ENABLE);
while (DMA_GetCmdStatus(self->dma_stream) == DISABLE) {
}
// enable DAC channel
DAC_Cmd(self->dac_channel, ENABLE);
// enable DMA for DAC channel
DAC_DMACmd(self->dac_channel, ENABLE);
//printf("DMA: %p %lu\n", bufinfo.buf, bufinfo.len);
mp_obj_t pyb_audio_fill(mp_obj_t self_in, mp_obj_t val) {
audio_fill(mp_obj_get_int(val));
return mp_const_none;
}
STATIC MP_DEFINE_CONST_FUN_OBJ_2(pyb_audio_noise_obj, pyb_audio_noise);
STATIC MP_DEFINE_CONST_FUN_OBJ_2(pyb_audio_triangle_obj, pyb_audio_triangle);
STATIC MP_DEFINE_CONST_FUN_OBJ_2(pyb_audio_dac_obj, pyb_audio_dac);
STATIC MP_DEFINE_CONST_FUN_OBJ_1(pyb_audio_is_full_obj, pyb_audio_is_full);
STATIC MP_DEFINE_CONST_FUN_OBJ_2(pyb_audio_fill_obj, pyb_audio_fill);
STATIC MP_DEFINE_CONST_FUN_OBJ_KW(pyb_audio_dma_obj, 3, pyb_audio_dma);
STATIC const mp_method_t pyb_audio_methods[] = {
{ "noise", &pyb_audio_noise_obj },
{ "triangle", &pyb_audio_triangle_obj },
{ "dac", &pyb_audio_dac_obj },
{ "is_full", &pyb_audio_is_full_obj },
{ "fill", &pyb_audio_fill_obj },
{ "dma", &pyb_audio_dma_obj },
{ NULL, NULL },
};
@ -94,8 +207,8 @@ STATIC const mp_obj_type_t pyb_audio_type = {
.methods = pyb_audio_methods,
};
STATIC const pyb_audio_t pyb_audio_channel_1 = {{&pyb_audio_type}, 1};
STATIC const pyb_audio_t pyb_audio_channel_2 = {{&pyb_audio_type}, 2};
STATIC const pyb_audio_t pyb_audio_channel_1 = {{&pyb_audio_type}, DAC_Channel_1, DMA1_Stream5};
STATIC const pyb_audio_t pyb_audio_channel_2 = {{&pyb_audio_type}, DAC_Channel_2, DMA1_Stream6};
// create the audio object
// currently support either DAC1 on X5 (id = 1) or DAC2 on X6 (id = 2)
@ -106,17 +219,14 @@ STATIC mp_obj_t pyb_Audio(mp_obj_t id) {
int dac_id = mp_obj_get_int(id);
uint pin;
uint channel;
mp_obj_t dac_obj;
const pyb_audio_t *dac_obj;
if (dac_id == 1) {
pin = GPIO_Pin_4;
channel = DAC_Channel_1;
dac_obj = (mp_obj_t)&pyb_audio_channel_1;
dac_obj = &pyb_audio_channel_1;
} else {
pin = GPIO_Pin_5;
channel = DAC_Channel_2;
dac_obj = (mp_obj_t)&pyb_audio_channel_2;
dac_obj = &pyb_audio_channel_2;
}
// DAC channel configuration
@ -130,19 +240,17 @@ STATIC mp_obj_t pyb_Audio(mp_obj_t id) {
DAC_InitTypeDef DAC_InitStructure;
DAC_InitStructure.DAC_Trigger = DAC_Trigger_None;
DAC_InitStructure.DAC_WaveGeneration = DAC_WaveGeneration_None;
DAC_InitStructure.DAC_LFSRUnmask_TriangleAmplitude = DAC_TriangleAmplitude_1023;
DAC_InitStructure.DAC_OutputBuffer = DAC_OutputBuffer_Enable;
DAC_Init(channel, &DAC_InitStructure);
DAC_Init(dac_obj->dac_channel, &DAC_InitStructure);
// Enable DAC Channel
DAC_Cmd(channel, ENABLE);
DAC_Cmd(dac_obj->dac_channel, ENABLE);
// from now on use DAC_SetChannel[12]Data to trigger a conversion
sample_buf_in = 0;
sample_buf_out = 0;
// return static object
return dac_obj;
return (mp_obj_t)dac_obj;
}
MP_DEFINE_CONST_FUN_OBJ_1(pyb_Audio_obj, pyb_Audio);

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