Set AD4030 series device to do two data bit transitions per clock cycle per
active lane when specified by firmware. The dual data rate (DDR) feature is
available only for host clock mode and echo clock mode.
Co-developed-by: Sergiu Cuciurean <sergiu.cuciurean@xxxxxxxxxx>
Signed-off-by: Sergiu Cuciurean <sergiu.cuciurean@xxxxxxxxxx>
Signed-off-by: Marcelo Schmitt <marcelo.schmitt@xxxxxxxxxx>
---
drivers/iio/adc/ad4030.c | 11 +++++++++++
1 file changed, 11 insertions(+)
diff --git a/drivers/iio/adc/ad4030.c b/drivers/iio/adc/ad4030.c
index a5931056936a..37ba00097efe 100644
--- a/drivers/iio/adc/ad4030.c
+++ b/drivers/iio/adc/ad4030.c
@@ -74,6 +74,7 @@
(AD4030_REG_GAIN_X0_MSB + (AD4030_REG_GAIN_BYTES_NB * (ch)))
#define AD4030_REG_MODES 0x20
#define AD4030_REG_MODES_MASK_OUT_DATA_MODE GENMASK(2, 0)
+#define AD4030_REG_MODES_MASK_DDR_MODE BIT(3)
#define AD4030_REG_MODES_MASK_CLOCK_MODE GENMASK(5, 4)
#define AD4030_REG_MODES_MASK_LANE_MODE GENMASK(7, 6)
#define AD4030_REG_OSCILATOR 0x21
@@ -175,6 +176,7 @@ struct ad4030_state {
enum ad4030_out_mode mode;
enum ad4030_lane_mode lane_mode;
enum ad4030_clock_mode clock_mode;
+ bool ddr;
/* offload sampling spi message */
struct spi_transfer offload_xfer;
struct spi_message offload_msg;
@@ -1218,6 +1220,9 @@ static void ad4030_prepare_offload_msg(struct ad4030_state *st)
else
offload_bpw = data_width / (1 << st->lane_mode);
+ if (st->ddr)
+ offload_bpw /= 2;
+
st->offload_xfer.speed_hz = AD4030_SPI_MAX_REG_XFER_SPEED;
st->offload_xfer.bits_per_word = offload_bpw;
st->offload_xfer.len = roundup_pow_of_two(BITS_TO_BYTES(offload_bpw));
@@ -1271,6 +1276,12 @@ static int ad4030_config(struct ad4030_state *st)
reg_modes |= FIELD_PREP(AD4030_REG_MODES_MASK_CLOCK_MODE,
ret >= 0 ? ret : AD4030_SPI_CLOCK_MODE);
+ /* DDR is only valid for echo clock and host clock modes */
+ if (ret == AD4030_ECHO_CLOCK_MODE || ret == AD4030_CLOCK_HOST_MODE) {
+ st->ddr = device_property_read_bool(dev, "adi,dual-data-rate");
+ reg_modes |= FIELD_PREP(AD4030_REG_MODES_MASK_DDR_MODE, st->ddr);
+ }
+
ret = regmap_write(st->regmap, AD4030_REG_MODES, reg_modes);
if (ret)
return ret;
--
2.39.2
