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drivers: adc: get resolutions from dtsi for stm32 adc
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Simplify the STM32 ADC driver code by using the new ADC resolutions
property in dtsi files.

Signed-off-by: Guillaume Gautier <[email protected]>
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@gautierg-st @carlescufi
gautierg-st authored and carlescufi committed Apr 26, 2023
1 parent 5c68b12 commit f3a8279
Showing 1 changed file with 85 additions and 98 deletions.
183 changes: 85 additions & 98 deletions drivers/adc/adc_stm32.c
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Original file line number Diff line number Diff line change
Expand Up @@ -40,6 +40,7 @@
LOG_MODULE_REGISTER(adc_stm32);

#include <zephyr/drivers/clock_control/stm32_clock_control.h>
#include <zephyr/dt-bindings/adc/stm32_adc.h>
#include <zephyr/irq.h>

#if defined(CONFIG_SOC_SERIES_STM32F3X)
Expand Down Expand Up @@ -100,31 +101,6 @@ static const uint32_t table_seq_len[] = {
};
#endif

#define RES(n) LL_ADC_RESOLUTION_##n##B
static const uint32_t table_resolution[] = {
#if defined(CONFIG_SOC_SERIES_STM32F1X) || \
defined(STM32F3X_ADC_V2_5)
RES(12),
#elif defined(CONFIG_SOC_SERIES_STM32U5X)
RES(6),
RES(8),
RES(10),
RES(12),
RES(14),
#elif !defined(CONFIG_SOC_SERIES_STM32H7X)
RES(6),
RES(8),
RES(10),
RES(12),
#else
RES(8),
RES(10),
RES(12),
RES(14),
RES(16),
#endif
};

#define SMP_TIME(x, y) LL_ADC_SAMPLINGTIME_##x##CYCLE##y

/*
Expand Down Expand Up @@ -299,6 +275,8 @@ struct adc_stm32_cfg {
int8_t temp_channel;
int8_t vref_channel;
int8_t vbat_channel;
int8_t res_table_size;
const uint32_t res_table[];
};

#ifdef CONFIG_ADC_STM32_SHARED_IRQS
Expand Down Expand Up @@ -834,72 +812,88 @@ static void dma_callback(const struct device *dev, void *user_data,
}
#endif /* CONFIG_ADC_STM32_DMA */

static int start_read(const struct device *dev,
const struct adc_sequence *sequence)
static uint8_t get_reg_value(const struct device *dev, uint32_t reg,
uint32_t shift, uint32_t mask)
{
const struct adc_stm32_cfg *config = dev->config;
struct adc_stm32_data *data = dev->data;
ADC_TypeDef *adc = (ADC_TypeDef *)config->base;
uint8_t resolution;
int err;

switch (sequence->resolution) {
#if defined(CONFIG_SOC_SERIES_STM32F1X) || \
defined(STM32F3X_ADC_V2_5)
case 12:
resolution = table_resolution[0];
break;
#elif defined(CONFIG_SOC_SERIES_STM32U5X)
case 6:
resolution = table_resolution[0];
break;
case 8:
resolution = table_resolution[1];
break;
case 10:
resolution = table_resolution[2];
break;
case 12:
resolution = table_resolution[3];
break;
case 14:
resolution = table_resolution[4];
break;
#elif !defined(CONFIG_SOC_SERIES_STM32H7X)
case 6:
resolution = table_resolution[0];
break;
case 8:
resolution = table_resolution[1];
break;
case 10:
resolution = table_resolution[2];
break;
case 12:
resolution = table_resolution[3];
break;
#else
case 8:
resolution = table_resolution[0];
break;
case 10:
resolution = table_resolution[1];
break;
case 12:
resolution = table_resolution[2];
break;
case 14:
resolution = table_resolution[3];
break;
case 16:
resolution = table_resolution[4];
break;
#endif
default:
uintptr_t addr = (uintptr_t)adc + reg;

return ((*(volatile uint32_t *)addr >> shift) & mask);
}

static void set_reg_value(const struct device *dev, uint32_t reg,
uint32_t shift, uint32_t mask, uint32_t value)
{
const struct adc_stm32_cfg *config = dev->config;
ADC_TypeDef *adc = (ADC_TypeDef *)config->base;

uintptr_t addr = (uintptr_t)adc + reg;

MODIFY_REG(*(volatile uint32_t *)addr, (mask << shift), (value << shift));
}

static int set_resolution(const struct device *dev,
const struct adc_sequence *sequence)
{
const struct adc_stm32_cfg *config = dev->config;
ADC_TypeDef *adc = (ADC_TypeDef *)config->base;
uint8_t res_reg_addr = 0xFF;
uint8_t res_shift = 0;
uint8_t res_mask = 0;
uint8_t res_reg_val = 0;
int i;

for (i = 0; i < config->res_table_size; i++) {
if (sequence->resolution == STM32_ADC_GET_REAL_VAL(config->res_table[i])) {
res_reg_addr = STM32_ADC_GET_REG(config->res_table[i]);
res_shift = STM32_ADC_GET_SHIFT(config->res_table[i]);
res_mask = STM32_ADC_GET_MASK(config->res_table[i]);
res_reg_val = STM32_ADC_GET_REG_VAL(config->res_table[i]);
break;
}
}

if (i == config->res_table_size) {
LOG_ERR("Invalid resolution");
return -EINVAL;
}

/*
* Some MCUs (like STM32F1x) have no register to configure resolution.
* These MCUs have a register address value of 0xFF and should be
* ignored.
*/
if (res_reg_addr != 0xFF) {
/*
* We don't use LL_ADC_SetResolution and LL_ADC_GetResolution
* because they don't strictly use hardware resolution values
* and makes internal conversions for some series.
* (see stm32h7xx_ll_adc.h)
* Instead we set the register ourselves if needed.
*/
if (get_reg_value(dev, res_reg_addr, res_shift, res_mask) != res_reg_val) {
/*
* Writing ADC_CFGR1 register while ADEN bit is set
* resets RES[1:0] bitfield. We need to disable and enable adc.
*/
adc_stm32_disable(adc);
set_reg_value(dev, res_reg_addr, res_shift, res_mask, res_reg_val);
}
}

return 0;
}

static int start_read(const struct device *dev,
const struct adc_sequence *sequence)
{
const struct adc_stm32_cfg *config = dev->config;
struct adc_stm32_data *data = dev->data;
ADC_TypeDef *adc = (ADC_TypeDef *)config->base;
int err;

data->buffer = sequence->buffer;
data->channels = sequence->channels;
data->channel_count = POPCOUNT(data->channels);
Expand Down Expand Up @@ -931,6 +925,12 @@ static int start_read(const struct device *dev,
}
#endif

/* Check and set the resolution */
err = set_resolution(dev, sequence);
if (err < 0) {
return err;
}

uint8_t channel_id;
uint8_t channel_index = 0;

Expand Down Expand Up @@ -1005,21 +1005,6 @@ static int start_read(const struct device *dev,
return err;
}

#if defined(CONFIG_SOC_SERIES_STM32G0X) || \
defined(CONFIG_SOC_SERIES_STM32WLX)
if (LL_ADC_GetResolution(adc) != resolution) {
/*
* Writing ADC_CFGR1 register while ADEN bit is set
* resets RES[1:0] bitfield. We need to disable and enable adc.
*/
adc_stm32_disable(adc);
LL_ADC_SetResolution(adc, resolution);
}
#elif !defined(CONFIG_SOC_SERIES_STM32F1X) && \
!defined(STM32F3X_ADC_V2_5)
LL_ADC_SetResolution(adc, resolution);
#endif

#if defined(CONFIG_SOC_SERIES_STM32C0X) || \
defined(CONFIG_SOC_SERIES_STM32G0X) || \
defined(CONFIG_SOC_SERIES_STM32G4X) || \
Expand Down Expand Up @@ -1707,6 +1692,8 @@ static const struct adc_stm32_cfg adc_stm32_cfg_##index = { \
.temp_channel = DT_INST_PROP_OR(index, temp_channel, 0xFF), \
.vref_channel = DT_INST_PROP_OR(index, vref_channel, 0xFF), \
.vbat_channel = DT_INST_PROP_OR(index, vbat_channel, 0xFF), \
.res_table_size = DT_INST_PROP_LEN(index, resolutions), \
.res_table = DT_INST_PROP(index, resolutions), \
}; \
\
static struct adc_stm32_data adc_stm32_data_##index = { \
Expand Down

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