[PATCH v5 07/20] iio: adc: ad7768: Add power mode helper

From: Janani Sunil

Date: Fri Aug 28 2026 - 11:34:21 EST


Describe each power mode and its internal master-clock divisor in a
table. Replace the open-coded fast-mode setup with a helper that records
the active mode, preparing for dynamic mode selection.

Signed-off-by: Janani Sunil <janani.sunil@xxxxxxxxxx>
---
drivers/iio/adc/ad7768.c | 52 +++++++++++++++++++++++++++++++++++++++++-------
1 file changed, 45 insertions(+), 7 deletions(-)

diff --git a/drivers/iio/adc/ad7768.c b/drivers/iio/adc/ad7768.c
index ccd457c75224..67db6f4971a2 100644
--- a/drivers/iio/adc/ad7768.c
+++ b/drivers/iio/adc/ad7768.c
@@ -43,6 +43,8 @@
#define AD7768_REG_POWER_MODE 0x04
#define AD7768_SLEEP_MODE_MSK BIT(7)
#define AD7768_POWER_MODE_POWER_MODE_MSK GENMASK(5, 4)
+#define AD7768_POWER_MODE_POWER_MODE_LOW 0x0
+#define AD7768_POWER_MODE_POWER_MODE_MEDIAN 0x2
#define AD7768_POWER_MODE_POWER_MODE_FAST 0x3
#define AD7768_POWER_MODE_LVDS_ENABLE BIT(3)
#define AD7768_POWER_MODE_MCLK_DIV_MSK GENMASK(1, 0)
@@ -112,6 +114,17 @@ enum ad7768_clock_source {
AD7768_CLOCK_SOURCE_LVDS,
};

+struct ad7768_power_mode_info {
+ unsigned int mode;
+ unsigned int mclk_div;
+};
+
+static const struct ad7768_power_mode_info ad7768_power_modes[] = {
+ { .mode = AD7768_POWER_MODE_POWER_MODE_LOW, .mclk_div = 32 },
+ { .mode = AD7768_POWER_MODE_POWER_MODE_MEDIAN, .mclk_div = 8 },
+ { .mode = AD7768_POWER_MODE_POWER_MODE_FAST, .mclk_div = 4 },
+};
+
struct ad7768_precharge_config {
bool prebufp_en;
bool prebufn_en;
@@ -136,6 +149,7 @@ struct ad7768_state {
struct clk *mclk;
unsigned int datalines;
enum ad7768_clock_source clock_source;
+ unsigned int power_mode_idx;
const struct ad7768_chip_info *chip_info;
struct iio_backend *back;
unsigned int vref_uV[2];
@@ -333,6 +347,36 @@ static int ad7768_sync(struct ad7768_state *st)
AD7768_DATA_CONTROL_SPI_SYNC);
}

+static int ad7768_set_power_mode(struct ad7768_state *st,
+ unsigned int mode_idx)
+{
+ const struct ad7768_power_mode_info *mode_info;
+ int ret;
+
+ mode_info = &ad7768_power_modes[mode_idx];
+ ret = regmap_update_bits(st->regmap, AD7768_REG_POWER_MODE,
+ AD7768_POWER_MODE_POWER_MODE_MSK,
+ FIELD_PREP(AD7768_POWER_MODE_POWER_MODE_MSK,
+ mode_info->mode));
+ if (ret)
+ return ret;
+
+ ret = regmap_update_bits(st->regmap, AD7768_REG_POWER_MODE,
+ AD7768_POWER_MODE_MCLK_DIV_MSK,
+ FIELD_PREP(AD7768_POWER_MODE_MCLK_DIV_MSK,
+ mode_info->mode));
+ if (ret)
+ return ret;
+
+ ret = ad7768_sync(st);
+ if (ret)
+ return ret;
+
+ st->power_mode_idx = mode_idx;
+
+ return 0;
+}
+
static int ad7768_update_scan_mode(struct iio_dev *indio_dev,
const unsigned long *scan_mask)
{
@@ -482,13 +526,7 @@ static int ad7768_configure_capture(struct ad7768_state *st)
unsigned int dclk_div;
int ret;

- ret = regmap_update_bits(st->regmap, AD7768_REG_POWER_MODE,
- AD7768_POWER_MODE_POWER_MODE_MSK |
- AD7768_POWER_MODE_MCLK_DIV_MSK,
- FIELD_PREP(AD7768_POWER_MODE_POWER_MODE_MSK,
- AD7768_POWER_MODE_POWER_MODE_FAST) |
- FIELD_PREP(AD7768_POWER_MODE_MCLK_DIV_MSK,
- AD7768_POWER_MODE_POWER_MODE_FAST));
+ ret = ad7768_set_power_mode(st, ARRAY_SIZE(ad7768_power_modes) - 1);
if (ret)
return ret;


--
2.43.0