kopia lustrzana https://github.com/OpenRTX/OpenRTX
Audio device driver for STM32F4xx PWM-based 8-bit DAC emulation
Silvano Seva
rodzic
efb5f22750
commit
5aed3e3316
|
|
@ -0,0 +1,174 @@
|
|||
/***************************************************************************
|
||||
* Copyright (C) 2023 by Federico Amedeo Izzo IU2NUO, *
|
||||
* Niccolò Izzo IU2KIN *
|
||||
* Frederik Saraci IU2NRO *
|
||||
* Silvano Seva IU2KWO *
|
||||
* *
|
||||
* This program is free software; you can redistribute it and/or modify *
|
||||
* it under the terms of the GNU General Public License as published by *
|
||||
* the Free Software Foundation; either version 3 of the License, or *
|
||||
* (at your option) any later version. *
|
||||
* *
|
||||
* This program is distributed in the hope that it will be useful, *
|
||||
* but WITHOUT ANY WARRANTY; without even the implied warranty of *
|
||||
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
|
||||
* GNU General Public License for more details. *
|
||||
* *
|
||||
* You should have received a copy of the GNU General Public License *
|
||||
* along with this program; if not, see <http://www.gnu.org/licenses/> *
|
||||
***************************************************************************/
|
||||
|
||||
#include <kernel/scheduler/scheduler.h>
|
||||
#include <data_conversion.h>
|
||||
#include <DmaStream.hpp>
|
||||
#include <Timer.hpp>
|
||||
#include <miosix.h>
|
||||
#include <errno.h>
|
||||
#include "stm32_pwm.h"
|
||||
|
||||
|
||||
using Dma1_Stream2 = DmaStream< DMA1_BASE, 2, 1, 3 >; // DMA 1, Stream 2, channel 1, very high priority
|
||||
|
||||
|
||||
static const struct PwmChannelCfg *config; // Config
|
||||
static struct streamCtx *context; // Current stream context
|
||||
static StreamHandler stream(Dma1_Stream2::init(10, DataSize::_16BIT, 1)); // DMA stream handler
|
||||
static Timer tim(TIM7_BASE); // Trigger timebase
|
||||
|
||||
|
||||
/**
|
||||
* \internal
|
||||
* Stop an ongoing transfer, deactivating timers and DMA stream.
|
||||
*/
|
||||
static void stopTransfer()
|
||||
{
|
||||
tim.stop();
|
||||
config->stopCbk();
|
||||
context->running = 0;
|
||||
}
|
||||
|
||||
/**
|
||||
* \internal
|
||||
* Actual implementation of DMA interrupt handler.
|
||||
*/
|
||||
void __attribute__((used)) DMA_Handler()
|
||||
{
|
||||
Dma1_Stream2::IRQhandleInterrupt(&stream);
|
||||
}
|
||||
|
||||
void __attribute__((naked)) DMA1_Stream2_IRQHandler()
|
||||
{
|
||||
saveContext();
|
||||
asm volatile("bl _Z11DMA_Handlerv");
|
||||
restoreContext();
|
||||
}
|
||||
|
||||
|
||||
|
||||
void stm32pwm_init()
|
||||
{
|
||||
// Enable peripherals
|
||||
RCC->APB1ENR |= RCC_APB1ENR_TIM7EN;
|
||||
__DSB();
|
||||
|
||||
// Init DMA stream
|
||||
stream.setEndTransferCallback(stopTransfer);
|
||||
}
|
||||
|
||||
void stm32pwm_terminate()
|
||||
{
|
||||
if(stream.running())
|
||||
stream.halt();
|
||||
|
||||
RCC->APB1ENR &= ~RCC_APB1ENR_TIM7EN;
|
||||
__DSB();
|
||||
}
|
||||
|
||||
static int stm32pwm_start(const uint8_t instance, const void *cfg,
|
||||
struct streamCtx *ctx)
|
||||
{
|
||||
(void) instance;
|
||||
|
||||
if(ctx == NULL)
|
||||
return -EINVAL;
|
||||
|
||||
if((ctx->running != 0) || stream.running())
|
||||
return -EBUSY;
|
||||
|
||||
__disable_irq();
|
||||
ctx->running = 1;
|
||||
__enable_irq();
|
||||
|
||||
context = ctx;
|
||||
config = reinterpret_cast< const struct PwmChannelCfg *>(cfg);
|
||||
|
||||
/*
|
||||
* Convert buffer elements from int16_t to unsigned 12 bit values as required
|
||||
* by the DAC. Processing can be done in-place because the API mandates that
|
||||
* the function caller does not modify the buffer content once this function
|
||||
* has been called.
|
||||
*/
|
||||
S16toU8(ctx->buffer, ctx->bufSize);
|
||||
|
||||
bool circ = false;
|
||||
if(ctx->bufMode == BUF_CIRC_DOUBLE)
|
||||
circ = true;
|
||||
|
||||
stream.start(config->pwmReg, ctx->buffer, ctx->bufSize, circ);
|
||||
config->startCbk();
|
||||
|
||||
// Configure trigger
|
||||
tim.setUpdateFrequency(ctx->sampleRate);
|
||||
tim.enableDmaTrigger(true);
|
||||
tim.start();
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
static int stm32pwm_idleBuf(struct streamCtx *ctx, stream_sample_t **buf)
|
||||
{
|
||||
*buf = reinterpret_cast< stream_sample_t *>(stream.idleBuf());
|
||||
|
||||
return ctx->bufSize/2;
|
||||
}
|
||||
|
||||
static int stm32pwm_sync(struct streamCtx *ctx, uint8_t dirty)
|
||||
{
|
||||
if((ctx->bufMode == BUF_CIRC_DOUBLE) && (dirty != 0))
|
||||
{
|
||||
void *ptr = stream.idleBuf();
|
||||
S16toU8(reinterpret_cast< int16_t *>(ptr), ctx->bufSize/2);
|
||||
}
|
||||
|
||||
bool ok = stream.sync();
|
||||
if(ok) return 0;
|
||||
|
||||
return -1;
|
||||
}
|
||||
|
||||
static void stm32pwm_stop(struct streamCtx *ctx)
|
||||
{
|
||||
if(ctx->running == 0)
|
||||
return;
|
||||
|
||||
stream.stop();
|
||||
}
|
||||
|
||||
static void stm32pwm_halt(struct streamCtx *ctx)
|
||||
{
|
||||
if(ctx->running == 0)
|
||||
return;
|
||||
|
||||
stream.halt();
|
||||
}
|
||||
|
||||
#pragma GCC diagnostic ignored "-Wpedantic"
|
||||
const struct audioDriver stm32_pwm_audio_driver =
|
||||
{
|
||||
.start = stm32pwm_start,
|
||||
.data = stm32pwm_idleBuf,
|
||||
.sync = stm32pwm_sync,
|
||||
.stop = stm32pwm_stop,
|
||||
.terminate = stm32pwm_halt
|
||||
};
|
||||
#pragma GCC diagnostic pop
|
||||
|
|
@ -0,0 +1,69 @@
|
|||
/***************************************************************************
|
||||
* Copyright (C) 2023 by Federico Amedeo Izzo IU2NUO, *
|
||||
* Niccolò Izzo IU2KIN *
|
||||
* Frederik Saraci IU2NRO *
|
||||
* Silvano Seva IU2KWO *
|
||||
* *
|
||||
* This program is free software; you can redistribute it and/or modify *
|
||||
* it under the terms of the GNU General Public License as published by *
|
||||
* the Free Software Foundation; either version 3 of the License, or *
|
||||
* (at your option) any later version. *
|
||||
* *
|
||||
* This program is distributed in the hope that it will be useful, *
|
||||
* but WITHOUT ANY WARRANTY; without even the implied warranty of *
|
||||
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
|
||||
* GNU General Public License for more details. *
|
||||
* *
|
||||
* You should have received a copy of the GNU General Public License *
|
||||
* along with this program; if not, see <http://www.gnu.org/licenses/> *
|
||||
***************************************************************************/
|
||||
|
||||
#ifndef STM32_PWM_H
|
||||
#define STM32_PWM_H
|
||||
|
||||
#include <stdbool.h>
|
||||
#include <stdint.h>
|
||||
#include <stm32f4xx.h>
|
||||
#include <interfaces/audio.h>
|
||||
|
||||
#ifdef __cplusplus
|
||||
extern "C" {
|
||||
#endif
|
||||
|
||||
/**
|
||||
* Driver STM32 PWM used as audio output stream device.
|
||||
* Input data format is signed 16-bit, internally converted to unsigned 8-bit
|
||||
* values for compatibility with the hardware.
|
||||
*
|
||||
* The driver uses the following peripherals: DMA1_Stream2, TIM7
|
||||
*/
|
||||
|
||||
/**
|
||||
* Data structure holding the configuration for a given DAC channel.
|
||||
*/
|
||||
struct PwmChannelCfg
|
||||
{
|
||||
volatile uint32_t *pwmReg; ///< Address of PWM duty cycle register.
|
||||
void (*startCbk)(void); ///< Callback function for additional setup operations.
|
||||
void (*stopCbk)(void); ///< Callback function for additional end operations.
|
||||
};
|
||||
|
||||
|
||||
extern const struct audioDriver stm32_pwm_audio_driver;
|
||||
|
||||
|
||||
/**
|
||||
* Initialize the driver and the peripherals.
|
||||
*/
|
||||
void stm32pwm_init();
|
||||
|
||||
/**
|
||||
* Shutdown the driver and the peripherals.
|
||||
*/
|
||||
void stm32pwm_terminate();
|
||||
|
||||
#ifdef __cplusplus
|
||||
}
|
||||
#endif
|
||||
|
||||
#endif /* STM32_PWM_H */
|
||||
Ładowanie…
Reference in New Issue