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driver: adc: npcx: prevent sleep when ADC is operating

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Entering deep sleep mode stops the source clock of the ADC module and
could corrupt the ongoing ADC conversion. This commit lets ADC driver
acquire the PM lock during the ADC operation (either single conversion
or repetitive scan) and release it when the ADC conversion stops.

Signed-off-by: Jun Lin <CHLin56@nuvoton.com>
This commit is contained in:
Jun Lin 2022-06-14 14:53:29 +08:00 • committed by Carles Cufí
commit d4a5203c18
1 changed files with 34 additions and 0 deletions
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34
drivers/adc/adc_npcx.c
View file

@ -12,6 +12,7 @@
#include <zephyr/drivers/clock_control.h>
#include <zephyr/drivers/pinctrl.h>
#include <zephyr/kernel.h>
#include <zephyr/pm/policy.h>
#include <soc.h>
#define ADC_CONTEXT_USES_KERNEL_TIMER
@ -117,12 +118,32 @@ struct adc_npcx_data {
uint16_t *buf_end;
/* Threshold comparator data pointer */
struct adc_npcx_threshold_data *threshold_data;
#ifdef CONFIG_PM
atomic_t current_pm_lock;
#endif
};
/* Driver convenience defines */
#define HAL_INSTANCE(dev) ((struct adc_reg *)((const struct adc_npcx_config *)(dev)->config)->base)
/* ADC local functions */
#ifdef CONFIG_PM
static void adc_npcx_pm_policy_state_lock_get(struct adc_npcx_data *data)
{
if (atomic_test_and_set_bit(&data->current_pm_lock, 0) == 0) {
pm_policy_state_lock_get(PM_STATE_SUSPEND_TO_IDLE, PM_ALL_SUBSTATES);
}
}
static void adc_npcx_pm_policy_state_lock_put(struct adc_npcx_data *data)
{
if (atomic_test_and_clear_bit(&data->current_pm_lock, 0) == 1) {
pm_policy_state_lock_put(PM_STATE_SUSPEND_TO_IDLE, PM_ALL_SUBSTATES);
}
}
#endif
static inline uint32_t npcx_thrctl_reg(const struct device *dev,
uint32_t ctl_no)
{
@ -179,6 +200,10 @@ static void adc_npcx_isr(const struct device *dev)
inst->ADCCS = 0;
/* Turn off ADC */
inst->ADCCNF &= ~(BIT(NPCX_ADCCNF_ADCEN));
#ifdef CONFIG_PM
adc_npcx_pm_policy_state_lock_put(data);
#endif
}
/* Inform sampling is done */
adc_context_on_sampling_done(&data->ctx, data->adc_dev);
@ -240,6 +265,9 @@ static void adc_npcx_start_scan(const struct device *dev)
struct adc_npcx_data *const data = dev->data;
struct adc_reg *const inst = HAL_INSTANCE(dev);
#ifdef CONFIG_PM
adc_npcx_pm_policy_state_lock_get(data);
#endif
/* Turn on ADC first */
inst->ADCCNF |= BIT(NPCX_ADCCNF_ADCEN);
@ -399,6 +427,9 @@ static void adc_npcx_set_repetitive(const struct device *dev, int chnsel,
inst->ADCCNF |= BIT(NPCX_ADCCNF_STOP);
if (enable) {
#ifdef CONFIG_PM
adc_npcx_pm_policy_state_lock_get(data);
#endif
/* Turn on ADC */
inst->ADCCNF |= BIT(NPCX_ADCCNF_ADCEN);
/* Set ADC conversion code to SW conversion mode */
@ -421,6 +452,9 @@ static void adc_npcx_set_repetitive(const struct device *dev, int chnsel,
inst->ADCCNF &= ~BIT(NPCX_ADCCNF_ADCRPTC);
/* Turn off ADC */
inst->ADCCNF &= ~BIT(NPCX_ADCCNF_ADCEN);
#ifdef CONFIG_PM
adc_npcx_pm_policy_state_lock_put(data);
#endif
} else {
/* Start conversion again */
inst->ADCCNF |= BIT(NPCX_ADCCNF_START);