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risc-v/esp32c3: Refactor ADC calibration

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Use calibration parameters from efuse rather than self-calibration.
This commit is contained in:
Dong Heng 2021-10-14 20:22:24 +08:00 committed by Gustavo Henrique Nihei
parent 298c372afa
commit 66023da10c
1 changed files with 140 additions and 35 deletions
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175
arch/risc-v/src/esp32c3/esp32c3_adc.c
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@ -38,6 +38,7 @@
#include "esp32c3_adc.h"
#include "hardware/esp32c3_system.h"
#include "hardware/esp32c3_efuse.h"
#include "hardware/esp32c3_saradc.h"
#include "hardware/esp32c3_gpio_sigmap.h"
#include "hardware/regi2c_ctrl.h"
@ -63,6 +64,16 @@
#define ADC_VAL_MASK (0xfff)
#define ADC_CAL_BASE_REG EFUSE_RD_SYS_DATA_PART1_0_REG
#define ADC_CAL_VER_OFF (128)
#define ADC_CAL_VER_LEN (3)
#define ADC_CAL_DATA_LEN (10)
#define ADC_CAL_DATA_COMP (1000)
#define ADC_CAL_VOL_LEN (10)
/* ADC input voltage attenuation, this affects measuring range */
#define ADC_ATTEN_DB_0 (0) /* Vmax = 800 mV */
@ -74,16 +85,32 @@
#if defined(CONFIG_ESP32C3_ADC_VOL_750)
# define ADC_ATTEN_DEF ADC_ATTEN_DB_0
# define ADC_VOL_VAL (750)
# define ADC_CAL_DATA_OFF (148)
# define ADC_CAL_VOL_OFF (188)
# define ADC_CAL_VOL_DEF (400)
#elif defined(CONFIG_ESP32C3_ADC_VOL_1050)
# define ADC_ATTEN_DEF ADC_ATTEN_DB_2_5
# define ADC_VOL_VAL (1050)
# define ADC_CAL_DATA_OFF (158)
# define ADC_CAL_VOL_OFF (198)
# define ADC_CAL_VOL_DEF (550)
#elif defined(CONFIG_ESP32C3_ADC_VOL_1300)
# define ADC_ATTEN_DEF ADC_ATTEN_DB_6
# define ADC_VOL_VAL (1300)
# define ADC_CAL_DATA_OFF (168)
# define ADC_CAL_VOL_OFF (208)
# define ADC_CAL_VOL_DEF (750)
#elif defined(CONFIG_ESP32C3_ADC_VOL_2500)
# define ADC_ATTEN_DEF ADC_ATTEN_DB_11
# define ADC_VOL_VAL (2500)
# define ADC_CAL_DATA_OFF (178)
# define ADC_CAL_VOL_OFF (218)
# define ADC_CAL_VOL_DEF (1370)
#endif
#define ADC_WORK_DELAY (1)
@ -214,6 +241,10 @@ static struct adc_dev_s g_adc1_chan4_dev =
static bool g_calibrated;
/* ADC calibration digital parameter */
static uint16_t g_cal_digit;
/* ADC clock reference */
static uint32_t g_clk_ref;
@ -224,6 +255,48 @@ static sem_t g_sem_excl = SEM_INITIALIZER(1);
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: read_efuse
*
* Description:
* Read Efuse data.
*
* Input Parameters:
* addr - register address
* b_off - bit offset
* b_size - bit size
*
* Returned Value:
* Efuse data.
*
****************************************************************************/
static uint32_t read_efuse(uint32_t addr, uint32_t b_off, uint32_t b_size)
{
uint32_t data;
uint32_t regval;
uint32_t shift = 32 - b_size;
uint32_t mask = UINT32_MAX >> shift;
uint32_t res = b_off % 32;
uint32_t regaddr = addr + (b_off / 32 * 4);
regval = getreg32(regaddr);
data = regval >> res;
if (res <= shift)
{
data &= mask;
}
else
{
shift = 32 - res;
regval = getreg32(regaddr + 4);
data |= (regval & (mask >> shift)) << shift;
}
return data;
}
/****************************************************************************
* Name: adc_enable_clk
*
@ -410,47 +483,74 @@ static void adc_calibrate(void)
uint16_t adc_max = 0;
uint16_t adc_min = UINT16_MAX;
uint32_t adc_sum = 0;
uint32_t regval;
/* Enable Vdef */
rom_i2c_writereg_mask(I2C_ADC, I2C_ADC_HOSTID,
I2C_ADC1_DEF, I2C_ADC1_DEF_MSB,
I2C_ADC1_DEF_LSB, 1);
/* Start sampling */
adc_samplecfg(ADC_CAL_CHANNEL);
/* Enable internal connect GND (for calibration). */
rom_i2c_writereg_mask(I2C_ADC, I2C_ADC_HOSTID,
I2C_ADC1_ENCAL_GND, I2C_ADC1_ENCAL_GND_MSB,
I2C_ADC1_ENCAL_GND_LSB, 1);
for (int i = 1; i < ADC_CAL_CNT_MAX ; i++)
regval = read_efuse(ADC_CAL_BASE_REG, ADC_CAL_VER_OFF, ADC_CAL_VER_LEN);
if (regval == 1)
{
adc_set_calibration(0);
adc = adc_read();
ainfo("Calibrate based on efuse data\n");
adc_sum += adc;
adc_max = MAX(adc, adc_max);
adc_min = MIN(adc, adc_min);
regval = read_efuse(ADC_CAL_BASE_REG, ADC_CAL_DATA_OFF,
ADC_CAL_DATA_LEN);
cali_val = regval + ADC_CAL_DATA_COMP;
}
else
{
ainfo("Calibrate based on GND voltage\n");
cali_val = (adc_sum - adc_max - adc_min) / (ADC_CAL_CNT_MAX - 2);
/* Enable Vdef */
/* Disable internal connect GND (for calibration). */
rom_i2c_writereg_mask(I2C_ADC, I2C_ADC_HOSTID,
I2C_ADC1_DEF, I2C_ADC1_DEF_MSB,
I2C_ADC1_DEF_LSB, 1);
rom_i2c_writereg_mask(I2C_ADC, I2C_ADC_HOSTID,
I2C_ADC1_ENCAL_GND,
I2C_ADC1_ENCAL_GND_MSB,
I2C_ADC1_ENCAL_GND_LSB, 0);
/* Start sampling */
adc_samplecfg(ADC_CAL_CHANNEL);
/* Enable internal connect GND (for calibration). */
rom_i2c_writereg_mask(I2C_ADC, I2C_ADC_HOSTID,
I2C_ADC1_ENCAL_GND, I2C_ADC1_ENCAL_GND_MSB,
I2C_ADC1_ENCAL_GND_LSB, 1);
for (int i = 1; i < ADC_CAL_CNT_MAX ; i++)
{
adc_set_calibration(0);
adc = adc_read();
adc_sum += adc;
adc_max = MAX(adc, adc_max);
adc_min = MIN(adc, adc_min);
}
cali_val = (adc_sum - adc_max - adc_min) / (ADC_CAL_CNT_MAX - 2);
/* Disable internal connect GND (for calibration). */
rom_i2c_writereg_mask(I2C_ADC, I2C_ADC_HOSTID,
I2C_ADC1_ENCAL_GND,
I2C_ADC1_ENCAL_GND_MSB,
I2C_ADC1_ENCAL_GND_LSB, 0);
}
ainfo("calibration value: %" PRIu16 "\n", cali_val);
/* Set final calibration parameters */
adc_set_calibration(cali_val);
/* Set calibration digital parameters */
regval = read_efuse(ADC_CAL_BASE_REG, ADC_CAL_VOL_OFF, ADC_CAL_VOL_LEN);
if (regval & BIT(ADC_CAL_VOL_LEN - 1))
{
g_cal_digit = 2000 - (regval & ~(BIT(ADC_CAL_VOL_LEN - 1)));
}
else
{
g_cal_digit = 2000 + regval;
}
}
/****************************************************************************
@ -470,7 +570,8 @@ static void adc_calibrate(void)
static void adc_read_work(struct adc_dev_s *dev)
{
int ret;
uint16_t adc;
uint32_t value;
int32_t adc;
struct adc_chan_s *priv = (struct adc_chan_s *)dev->ad_priv;
ret = sem_wait(&g_sem_excl);
@ -481,12 +582,15 @@ static void adc_read_work(struct adc_dev_s *dev)
}
adc_samplecfg(priv->channel);
adc = adc_read();
value = adc_read();
adc = (int32_t)(value * (UINT16_MAX * ADC_CAL_VOL_DEF / g_cal_digit) /
UINT16_MAX);
priv->cb->au_receive(dev, priv->channel, adc);
ainfo("channel: %" PRIu8 ", voltage: %" PRIu32 " mV\n", priv->channel,
(uint32_t)adc * ADC_VOL_VAL / ADC_CAL_VAL_MAX);
adc);
sem_post(&g_sem_excl);
}
@ -579,6 +683,7 @@ static int adc_setup(struct adc_dev_s *dev)
if (priv->ref > 0)
{
priv->ref++;
return OK;
}