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/* Copyright 2021 The Chromium OS Authors. All rights reserved.
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "adc.h"
#include "clock.h"
#include "common.h"
#include "console.h"
#include "dma.h"
#include "hooks.h"
#include "hwtimer.h"
#include "registers.h"
#include "task.h"
#include "timer.h"
#include "util.h"
struct mutex adc_lock;
struct adc_profile_t {
/* Register values. */
uint32_t cfgr1_reg;
uint32_t cfgr2_reg;
uint32_t smpr_reg; /* Default Sampling Rate */
uint32_t ier_reg;
/* DMA config. */
const struct dma_option *dma_option;
/* Size of DMA buffer, in units of ADC_CH_COUNT. */
int dma_buffer_size;
};
#ifdef CONFIG_ADC_PROFILE_SINGLE
#ifndef CONFIG_ADC_SAMPLE_TIME
#define CONFIG_ADC_SAMPLE_TIME STM32_ADC_SMPR_12_5_CY
#endif
#endif
#if defined(CHIP_FAMILY_STM32L4)
#define ADC_CALIBRATION_TIMEOUT_US 100000U
#define ADC_ENABLE_TIMEOUT_US 200000U
#define ADC_CONVERSION_TIMEOUT_US 200000U
#define NUMBER_OF_ADC_CHANNEL 2
uint8_t adc1_initialized;
#endif
#ifdef CONFIG_ADC_PROFILE_FAST_CONTINUOUS
#ifndef CONFIG_ADC_SAMPLE_TIME
#define CONFIG_ADC_SAMPLE_TIME STM32_ADC_SMPR_1_5_CY
#endif
static const struct dma_option dma_continuous = {
STM32_DMAC_ADC,
(void *)&STM32_ADC_DR,
STM32_DMA_CCR_MSIZE_32_BIT | STM32_DMA_CCR_PSIZE_32_BIT |
STM32_DMA_CCR_CIRC,
};
static const struct adc_profile_t profile = {
/* Sample all channels continuously using DMA */
.cfgr1_reg = STM32_ADC_CFGR1_OVRMOD | STM32_ADC_CFGR1_CONT |
STM32_ADC_CFGR1_DMACFG,
.cfgr2_reg = 0,
.smpr_reg = CONFIG_ADC_SAMPLE_TIME,
/* Fire interrupt at end of sequence. */
.ier_reg = STM32_ADC_IER_EOSEQIE,
.dma_option = &dma_continuous,
/* Double-buffer our samples. */
.dma_buffer_size = 2,
};
#endif
static void adc_init(const struct adc_t *adc)
{
/*
* If clock is already enabled, and ADC module is enabled
* then this is a warm reboot and ADC is already initialized.
*/
if (STM32_RCC_AHB2ENR & STM32_RCC_AHB2ENR_ADCEN &&
(STM32_ADC1_CR & STM32_ADC1_CR_ADEN))
return;
/* Enable ADC clock */
clock_enable_module(MODULE_ADC, 1);
/* set ADC clock to 20MHz */
STM32_ADC1_CCR &= ~0x003C0000;
STM32_ADC1_CCR |= 0x00080000;
STM32_RCC_AHB2ENR |= STM32_RCC_HB2_GPIOA;
STM32_RCC_AHB2ENR |= STM32_RCC_HB2_GPIOB;
/* Set ADC data resolution */
STM32_ADC1_CFGR &= ~STM32_ADC1_CFGR_CONT;
/* Set ADC conversion data alignment */
STM32_ADC1_CFGR &= ~STM32_ADC1_CFGR_ALIGN;
/* Set ADC delayed conversion mode */
STM32_ADC1_CFGR &= ~STM32_ADC1_CFGR_AUTDLY;
}
static void adc_configure(int ain_id, int ain_rank,
enum stm32_adc_smpr sample_rate)
{
/* Select Sampling time and channel to convert */
if (ain_id <= 10) {
STM32_ADC1_SMPR1 &= ~(7 << ((ain_id - 1) * 3));
STM32_ADC1_SMPR1 |= (sample_rate << ((ain_id - 1) * 3));
} else {
STM32_ADC1_SMPR2 &= ~(7 << ((ain_id - 11) * 3));
STM32_ADC1_SMPR2 |= (sample_rate << ((ain_id - 11) * 3));
}
/* Setup Rank */
STM32_ADC1_JSQR &= ~(0x03);
STM32_ADC1_JSQR |= NUMBER_OF_ADC_CHANNEL - 1;
STM32_ADC1_JSQR &= ~(0x1F << (((ain_rank - 1) * 6) + 8));
STM32_ADC1_JSQR |= (ain_id << (((ain_rank - 1) * 6) + 8));
/* Disable DMA */
STM32_ADC1_CFGR &= ~STM32_ADC1_CFGR_DMAEN;
}
int adc_read_channel(enum adc_channel ch)
{
const struct adc_t *adc = adc_channels + ch;
int value = 0;
uint32_t wait_loop_index;
mutex_lock(&adc_lock);
if (adc1_initialized == 0) {
adc_init(adc);
/* Configure Injected Channel N */
for (uint8_t i = 0; i < NUMBER_OF_ADC_CHANNEL; i++) {
const struct adc_t *adc = adc_channels + i;
adc_configure(adc->channel, adc->rank,
adc->sample_rate);
}
if ((STM32_ADC1_CR & STM32_ADC1_CR_ADEN) !=
STM32_ADC1_CR_ADEN) {
/* Disable ADC deep power down (enabled by default after
* reset state)
*/
STM32_ADC1_CR &= ~STM32_ADC1_CR_DEEPPWD;
/* Enable ADC internal voltage regulator */
STM32_ADC1_CR |= STM32_ADC1_CR_ADVREGEN;
}
/*
* Delay for ADC internal voltage regulator stabilization.
* Compute number of CPU cycles to wait for, from delay in us.
*
* Note: Variable divided by 2 to compensate partially
* CPU processing cycles (depends on compilation optimization).
*
* Note: If system core clock frequency is below 200kHz, wait
* time is only a few CPU processing cycles.
*/
wait_loop_index = ((20 * (80000000 / (100000 * 2))) / 10);
while (wait_loop_index-- != 0)
;
/* Run ADC self calibration */
STM32_ADC1_CR |= STM32_ADC1_CR_ADCAL;
/* wait for the end of calibration */
wait_loop_index = ((ADC_CALIBRATION_TIMEOUT_US *
(CPU_CLOCK / (100000 * 2))) /
10);
while (STM32_ADC1_CR & STM32_ADC1_CR_ADCAL) {
if (wait_loop_index-- == 0)
break;
}
/* Enable ADC */
STM32_ADC1_ISR |= STM32_ADC1_ISR_ADRDY;
STM32_ADC1_CR |= STM32_ADC1_CR_ADEN;
wait_loop_index =
((ADC_ENABLE_TIMEOUT_US * (CPU_CLOCK / (100000 * 2))) /
10);
while (!(STM32_ADC1_ISR & STM32_ADC1_ISR_ADRDY)) {
wait_loop_index--;
if (wait_loop_index == 0)
break;
}
adc1_initialized = 1;
}
/* Start injected conversion */
STM32_ADC1_CR |= BIT(3); /* JADSTART */
/* Wait for end of injected conversion */
wait_loop_index =
((ADC_CONVERSION_TIMEOUT_US * (CPU_CLOCK / (100000 * 2))) / 10);
while (!(STM32_ADC1_ISR & BIT(6))) {
if (wait_loop_index-- == 0)
break;
}
/* Clear JEOS bit */
STM32_ADC1_ISR |= BIT(6);
/* read converted value */
if (adc->rank == 1)
value = STM32_ADC1_JDR1;
if (adc->rank == 2)
value = STM32_ADC1_JDR2;
mutex_unlock(&adc_lock);
return value * adc->factor_mul / adc->factor_div + adc->shift;
}
void adc_disable(void)
{
/* Disable ADC */
/* Do not Set ADDIS when ADC is disabled */
adc1_initialized = 0;
if (STM32_ADC1_CR & STM32_ADC1_CR_ADEN)
STM32_ADC1_CR |= STM32_ADC1_CR_ADDIS;
/*
* Note that the ADC is not in OFF state immediately.
* Once the ADC is effectively put into OFF state,
* STM32_ADC_CR_ADDIS bit will be cleared by hardware.
*/
}
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