[PATCH 06/16] iio: adc: at91-sama5d2_adc: add 64 and 256 oversampling ratio

Claudiu Beznea
2022-06-09T08:30:40Z

Add 64 and 256 oversampling ratio support. It is necessary for temperature
sensor.

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
---
drivers/iio/adc/at91-sama5d2_adc.c | 31 +++++++++++++++++++++++++++---
1 file changed, 28 insertions(+), 3 deletions(-)

diff --git a/drivers/iio/adc/at91-sama5d2_adc.c b/drivers/iio/adc/at91-sama5d2_adc.c
index 7321a4b519af..b52f1020feaf 100644
--- a/drivers/iio/adc/at91-sama5d2_adc.c
+++ b/drivers/iio/adc/at91-sama5d2_adc.c
@@ -142,6 +142,8 @@ struct at91_adc_reg_layout {
#define AT91_SAMA5D2_EMR_OSR_1SAMPLES 0
#define AT91_SAMA5D2_EMR_OSR_4SAMPLES 1
#define AT91_SAMA5D2_EMR_OSR_16SAMPLES 2
+#define AT91_SAMA5D2_EMR_OSR_64SAMPLES 3
+#define AT91_SAMA5D2_EMR_OSR_256SAMPLES 4

/* Extended Mode Register - Averaging on single trigger event */
#define AT91_SAMA5D2_EMR_ASTE(V) ((V) << 20)
@@ -308,6 +310,8 @@ static const struct at91_adc_reg_layout sama7g5_layout = {
#define AT91_OSR_1SAMPLES 1
#define AT91_OSR_4SAMPLES 4
#define AT91_OSR_16SAMPLES 16
+#define AT91_OSR_64SAMPLES 64
+#define AT91_OSR_256SAMPLES 256

#define AT91_SAMA5D2_CHAN_SINGLE(index, num, addr) \
{ \
@@ -640,7 +644,9 @@ static const struct at91_adc_platform sama7g5_platform = {
.osr_mask = GENMASK(18, 16),
.osr_vals = BIT(AT91_SAMA5D2_EMR_OSR_1SAMPLES) |
BIT(AT91_SAMA5D2_EMR_OSR_4SAMPLES) |
- BIT(AT91_SAMA5D2_EMR_OSR_16SAMPLES),
+ BIT(AT91_SAMA5D2_EMR_OSR_16SAMPLES) |
+ BIT(AT91_SAMA5D2_EMR_OSR_64SAMPLES) |
+ BIT(AT91_SAMA5D2_EMR_OSR_256SAMPLES),
.chan_realbits = 16,
};

@@ -774,6 +780,18 @@ static int at91_adc_config_emr(struct at91_adc_state *st,
emr |= AT91_SAMA5D2_EMR_OSR(AT91_SAMA5D2_EMR_OSR_16SAMPLES,
osr_mask);
break;
+ case AT91_OSR_64SAMPLES:
+ if (!(osr_vals & BIT(AT91_SAMA5D2_EMR_OSR_64SAMPLES)))
+ return -EINVAL;
+ emr |= AT91_SAMA5D2_EMR_OSR(AT91_SAMA5D2_EMR_OSR_64SAMPLES,
+ osr_mask);
+ break;
+ case AT91_OSR_256SAMPLES:
+ if (!(osr_vals & BIT(AT91_SAMA5D2_EMR_OSR_256SAMPLES)))
+ return -EINVAL;
+ emr |= AT91_SAMA5D2_EMR_OSR(AT91_SAMA5D2_EMR_OSR_256SAMPLES,
+ osr_mask);
+ break;
}

at91_adc_writel(st, EMR, emr);
@@ -791,6 +809,10 @@ static int at91_adc_adjust_val_osr(struct at91_adc_state *st, int *val)
nbits = 13;
else if (st->oversampling_ratio == AT91_OSR_16SAMPLES)
nbits = 14;
+ else if (st->oversampling_ratio == AT91_OSR_64SAMPLES)
+ nbits = 15;
+ else if (st->oversampling_ratio == AT91_OSR_256SAMPLES)
+ nbits = 16;

/*
* We have nbits of real data and channel is registered as
@@ -1679,7 +1701,8 @@ static int at91_adc_write_raw(struct iio_dev *indio_dev,
switch (mask) {
case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
if ((val != AT91_OSR_1SAMPLES) && (val != AT91_OSR_4SAMPLES) &&
- (val != AT91_OSR_16SAMPLES))
+ (val != AT91_OSR_16SAMPLES) && (val != AT91_OSR_64SAMPLES) &&
+ (val != AT91_OSR_256SAMPLES))
return -EINVAL;
/* if no change, optimize out */
mutex_lock(&st->lock);
@@ -1897,7 +1920,9 @@ static IIO_CONST_ATTR(hwfifo_watermark_max, AT91_HWFIFO_MAX_SIZE_STR);
static IIO_CONST_ATTR(oversampling_ratio_available,
__stringify(AT91_OSR_1SAMPLES) " "
__stringify(AT91_OSR_4SAMPLES) " "
- __stringify(AT91_OSR_16SAMPLES));
+ __stringify(AT91_OSR_16SAMPLES) " "
+ __stringify(AT91_OSR_64SAMPLES) " "
+ __stringify(AT91_OSR_256SAMPLES));

static struct attribute *at91_adc_attributes[] = {
&iio_const_attr_oversampling_ratio_available.dev_attr.attr,
--
2.34.1