[PATCH v2 06/19] iio: adc: at91-sama5d2_adc: handle different EMR.OSR for different hw versions

Claudiu Beznea
2022-06-28T15:19:18Z

SAMA7G5 introduces 64 and 256 oversampling rates. Due to this EMR.OSR is 3
bits long. Change the code to reflect this. Commit prepares the code
for the addition of 64 and 256 oversampling rates.

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
---
drivers/iio/adc/at91-sama5d2_adc.c | 31 +++++++++++++++++-------------
1 file changed, 18 insertions(+), 13 deletions(-)

diff --git a/drivers/iio/adc/at91-sama5d2_adc.c b/drivers/iio/adc/at91-sama5d2_adc.c
index cd2b8190a8da..692707b6e3e3 100644
--- a/drivers/iio/adc/at91-sama5d2_adc.c
+++ b/drivers/iio/adc/at91-sama5d2_adc.c
@@ -138,8 +138,7 @@ struct at91_adc_reg_layout {
/* Extended Mode Register */
u16 EMR;
/* Extended Mode Register - Oversampling rate */
-#define AT91_SAMA5D2_EMR_OSR(V) ((V) << 16)
-#define AT91_SAMA5D2_EMR_OSR_MASK GENMASK(17, 16)
+#define AT91_SAMA5D2_EMR_OSR(V, M) (((V) << 16) & (M))
#define AT91_SAMA5D2_EMR_OSR_1SAMPLES 0
#define AT91_SAMA5D2_EMR_OSR_4SAMPLES 1
#define AT91_SAMA5D2_EMR_OSR_16SAMPLES 2
@@ -403,6 +402,7 @@ static const struct at91_adc_reg_layout sama7g5_layout = {
* @max_index: highest channel index (highest index may be higher
* than the total channel number)
* @hw_trig_cnt: number of possible hardware triggers
+ * @osr_mask: oversampling ratio bitmask on EMR register
*/
struct at91_adc_platform {
const struct at91_adc_reg_layout *layout;
@@ -414,6 +414,7 @@ struct at91_adc_platform {
unsigned int max_channels;
unsigned int max_index;
unsigned int hw_trig_cnt;
+ unsigned int osr_mask;
};

/**
@@ -612,6 +613,7 @@ static const struct at91_adc_platform sama5d2_platform = {
.max_index = AT91_SAMA5D2_MAX_CHAN_IDX,
#define AT91_SAMA5D2_HW_TRIG_CNT 3
.hw_trig_cnt = AT91_SAMA5D2_HW_TRIG_CNT,
+ .osr_mask = GENMASK(17, 16),
};

static const struct at91_adc_platform sama7g5_platform = {
@@ -627,6 +629,7 @@ static const struct at91_adc_platform sama7g5_platform = {
.max_index = AT91_SAMA7G5_MAX_CHAN_IDX,
#define AT91_SAMA7G5_HW_TRIG_CNT 3
.hw_trig_cnt = AT91_SAMA7G5_HW_TRIG_CNT,
+ .osr_mask = GENMASK(18, 16),
};

static int at91_adc_chan_xlate(struct iio_dev *indio_dev, int chan)
@@ -725,30 +728,32 @@ static void at91_adc_eoc_ena(struct at91_adc_state *st, unsigned int channel)
at91_adc_writel(st, EOC_IER, BIT(channel));
}

-static void at91_adc_config_emr(struct at91_adc_state *st)
+static void at91_adc_config_emr(struct at91_adc_state *st,
+ u32 oversampling_ratio)
{
/* configure the extended mode register */
unsigned int emr = at91_adc_readl(st, EMR);
+ unsigned int osr_mask = st->soc_info.platform->osr_mask;

/* select oversampling per single trigger event */
emr |= AT91_SAMA5D2_EMR_ASTE(1);

/* delete leftover content if it's the case */
- emr &= ~AT91_SAMA5D2_EMR_OSR_MASK;
+ emr &= ~osr_mask;

/* select oversampling ratio from configuration */
- switch (st->oversampling_ratio) {
+ switch (oversampling_ratio) {
case AT91_OSR_1SAMPLES:
- emr |= AT91_SAMA5D2_EMR_OSR(AT91_SAMA5D2_EMR_OSR_1SAMPLES) &
- AT91_SAMA5D2_EMR_OSR_MASK;
+ emr |= AT91_SAMA5D2_EMR_OSR(AT91_SAMA5D2_EMR_OSR_1SAMPLES,
+ osr_mask);
break;
case AT91_OSR_4SAMPLES:
- emr |= AT91_SAMA5D2_EMR_OSR(AT91_SAMA5D2_EMR_OSR_4SAMPLES) &
- AT91_SAMA5D2_EMR_OSR_MASK;
+ emr |= AT91_SAMA5D2_EMR_OSR(AT91_SAMA5D2_EMR_OSR_4SAMPLES,
+ osr_mask);
break;
case AT91_OSR_16SAMPLES:
- emr |= AT91_SAMA5D2_EMR_OSR(AT91_SAMA5D2_EMR_OSR_16SAMPLES) &
- AT91_SAMA5D2_EMR_OSR_MASK;
+ emr |= AT91_SAMA5D2_EMR_OSR(AT91_SAMA5D2_EMR_OSR_16SAMPLES,
+ osr_mask);
break;
}

@@ -1658,7 +1663,7 @@ static int at91_adc_write_raw(struct iio_dev *indio_dev,
mutex_lock(&st->lock);
st->oversampling_ratio = val;
/* update ratio */
- at91_adc_config_emr(st);
+ at91_adc_config_emr(st, val);
mutex_unlock(&st->lock);
iio_device_release_direct_mode(indio_dev);
return 0;
@@ -1838,7 +1843,7 @@ static void at91_adc_hw_init(struct iio_dev *indio_dev)
at91_adc_setup_samp_freq(indio_dev, st->soc_info.min_sample_rate);

/* configure extended mode register */
- at91_adc_config_emr(st);
+ at91_adc_config_emr(st, st->oversampling_ratio);
}

static ssize_t at91_adc_get_fifo_state(struct device *dev,