[PATCH RFC 4/5] iio: adc: ad4030: add support for ad4630-24 and ad4630-16

Esteban Blanc
2024-06-27T11:59:41Z

AD4630-24 and AD4630-16 are 2 channels ADCs. Both channels are
interleaved bit per bit on SDO line.

Signed-off-by: Esteban Blanc <eblanc@baylibre.com>
---
drivers/iio/adc/ad4030.c | 130 +++++++++++++++++++++++++++++++++++++++++++++--
1 file changed, 126 insertions(+), 4 deletions(-)

diff --git a/drivers/iio/adc/ad4030.c b/drivers/iio/adc/ad4030.c
index 1bcbcbd40a45..09d2f6d8cfe6 100644
--- a/drivers/iio/adc/ad4030.c
+++ b/drivers/iio/adc/ad4030.c
@@ -32,6 +32,8 @@
#define AD4030_REG_PRODUCT_ID_H 0x05
#define AD4030_REG_CHIP_GRADE 0x06
#define AD4030_REG_CHIP_GRADE_AD4030_24_GRADE 0x10
+#define AD4030_REG_CHIP_GRADE_AD4630_16_GRADE 0x03
+#define AD4030_REG_CHIP_GRADE_AD4630_24_GRADE 0x00
#define AD4030_REG_CHIP_GRADE_MASK_CHIP_GRADE GENMASK(7, 3)
#define AD4030_REG_SCRATCH_PAD 0x0A
#define AD4030_REG_SPI_REVISION 0x0B
@@ -391,7 +393,10 @@ static int ad4030_set_avg_frame_len(struct iio_dev *dev, unsigned int avg_len)
static bool ad4030_is_common_byte_asked(struct ad4030_state *st,
unsigned int mask)
{
- return mask & BIT(st->chip->num_channels);
+ if (st->chip->num_channels == 1)
+ return mask & BIT(st->chip->num_channels);
+
+ return mask & GENMASK(st->chip->num_channels + 1, st->chip->num_channels);
}

static int ad4030_set_mode(struct iio_dev *indio_dev, unsigned long mask)
@@ -412,6 +417,45 @@ static int ad4030_set_mode(struct iio_dev *indio_dev, unsigned long mask)
st->mode);
}

+/*
+ * @brief Descramble 2 32bits numbers out of a 64bits. The bits are interleaved: 1 bit for first
+ * number, 1 bit for the second, and so on...
+ */
+static void ad4030_extract_interleaved(u8 *src, u32 *out)
+{
+ u8 h0, h1, l0, l1;
+ u32 out0, out1;
+ u8 *out0_raw = (u8 *)&out0;
+ u8 *out1_raw = (u8 *)&out1;
+
+ for (int i = 0; i < 4; i++) {
+ h0 = src[i * 2];
+ l1 = src[i * 2 + 1];
+ h1 = h0 << 1;
+ l0 = l1 >> 1;
+
+ h0 &= 0xAA;
+ l0 &= 0x55;
+ h1 &= 0xAA;
+ l1 &= 0x55;
+
+ h0 = (h0 | h0 << 001) & 0xCC;
+ h1 = (h1 | h1 << 001) & 0xCC;
+ l0 = (l0 | l0 >> 001) & 0x33;
+ l1 = (l1 | l1 >> 001) & 0x33;
+ h0 = (h0 | h0 << 002) & 0xF0;
+ h1 = (h1 | h1 << 002) & 0xF0;
+ l0 = (l0 | l0 >> 002) & 0x0F;
+ l1 = (l1 | l1 >> 002) & 0x0F;
+
+ out0_raw[i] = h0 | l0;
+ out1_raw[i] = h1 | l1;
+ }
+
+ out[0] = out0;
+ out[1] = out1;
+}
+
static int ad4030_conversion(struct ad4030_state *st, const struct iio_chan_spec *chan)
{
unsigned int bytes_to_read = (BITS_TO_BYTES(chan->scan_type.realbits) +
@@ -437,10 +481,16 @@ static int ad4030_conversion(struct ad4030_state *st, const struct iio_chan_spec
ndelay(AD4030_TCONV_NS);

ret = spi_sync_transfer(st->spi, &xfer, 1);
- if (ret || (st->mode != AD4030_OUT_DATA_MD_16_DIFF_8_COM &&
- st->mode != AD4030_OUT_DATA_MD_24_DIFF_8_COM))
+ if (ret)
return ret;

+ if (st->chip->num_channels == 2)
+ ad4030_extract_interleaved(st->rx_data.raw, st->rx_data.val);
+
+ if (st->mode != AD4030_OUT_DATA_MD_16_DIFF_8_COM &&
+ st->mode != AD4030_OUT_DATA_MD_24_DIFF_8_COM)
+ return 0;
+
byte_index = st->chip->precision_bits == 16 ? 3 : 4;
for (i = 0; i < st->chip->num_channels; i++)
st->rx_data.common[i] = ((u8 *)&st->rx_data.val[i])[byte_index];
@@ -776,12 +826,25 @@ static int ad4030_detect_chip_info(const struct ad4030_state *st)

static int ad4030_config(struct ad4030_state *st)
{
+ int ret;
+ u8 reg_modes = 0;
+
st->min_offset = (int)BIT(st->chip->precision_bits) * -1;
st->max_offset = BIT(st->chip->precision_bits) - 1;
st->offset_avail[0] = st->min_offset;
st->offset_avail[1] = 1;
st->offset_avail[2] = st->max_offset;

+ if (st->chip->num_channels > 1)
+ reg_modes |= FIELD_PREP(AD4030_REG_MODES_MASK_LANE_MODE,
+ AD4030_LANE_MD_INTERLEAVED);
+ else
+ reg_modes |= FIELD_PREP(AD4030_REG_MODES_MASK_LANE_MODE, AD4030_LANE_MD_1_PER_CH);
+
+ ret = regmap_write(st->regmap, AD4030_REG_MODES, reg_modes);
+ if (ret)
+ return ret;
+
if (st->vio_uv < AD4030_VIO_THRESHOLD_UV)
return regmap_write(st->regmap, AD4030_REG_IO,
AD4030_REG_IO_MASK_IO2X);
@@ -863,8 +926,14 @@ static const unsigned long ad4030_channel_masks[] = {
0,
};

+static const unsigned long ad4630_channel_masks[] = {
+ GENMASK(1, 0),
+ GENMASK(3, 0),
+ 0,
+};
+
static const struct iio_scan_type ad4030_24_scan_types[] = {
- [AD4030_SCAN_TYPE_NORMAL] = {
+ [AD4030_OUT_DATA_MD_24_DIFF] = {
.sign = 's',
.storagebits = 32,
.realbits = 24,
@@ -880,6 +949,23 @@ static const struct iio_scan_type ad4030_24_scan_types[] = {
},
};

+static const struct iio_scan_type ad4030_16_scan_types[] = {
+ [AD4030_SCAN_TYPE_NORMAL] = {
+ .sign = 's',
+ .storagebits = 32,
+ .realbits = 16,
+ .shift = 16,
+ .endianness = IIO_BE,
+ },
+ [AD4030_SCAN_TYPE_AVG] = {
+ .sign = 's',
+ .storagebits = 32,
+ .realbits = 30,
+ .shift = 2,
+ .endianness = IIO_BE,
+ }
+};
+
static const struct ad4030_chip_info ad4030_24_chip_info = {
.name = "ad4030-24",
.available_masks = ad4030_channel_masks,
@@ -894,14 +980,50 @@ static const struct ad4030_chip_info ad4030_24_chip_info = {
.num_channels = 1,
};

+static const struct ad4030_chip_info ad4630_16_chip_info = {
+ .name = "ad4630-16",
+ .available_masks = ad4630_channel_masks,
+ .available_masks_len = ARRAY_SIZE(ad4630_channel_masks),
+ .channels = {
+ AD4030_CHAN_IN(0, ad4030_16_scan_types),
+ AD4030_CHAN_IN(1, ad4030_16_scan_types),
+ AD4030_CHAN_CMO(2),
+ AD4030_CHAN_CMO(3),
+ IIO_CHAN_SOFT_TIMESTAMP(4),
+ },
+ .grade = AD4030_REG_CHIP_GRADE_AD4630_16_GRADE,
+ .precision_bits = 16,
+ .num_channels = 2,
+};
+
+static const struct ad4030_chip_info ad4630_24_chip_info = {
+ .name = "ad4630-24",
+ .available_masks = ad4630_channel_masks,
+ .available_masks_len = ARRAY_SIZE(ad4630_channel_masks),
+ .channels = {
+ AD4030_CHAN_IN(0, ad4030_24_scan_types),
+ AD4030_CHAN_IN(1, ad4030_24_scan_types),
+ AD4030_CHAN_CMO(2),
+ AD4030_CHAN_CMO(3),
+ IIO_CHAN_SOFT_TIMESTAMP(4),
+ },
+ .grade = AD4030_REG_CHIP_GRADE_AD4630_24_GRADE,
+ .precision_bits = 24,
+ .num_channels = 2,
+};
+
static const struct spi_device_id ad4030_id_table[] = {
{ "ad4030-24", (kernel_ulong_t)&ad4030_24_chip_info },
+ { "ad4630-16", (kernel_ulong_t)&ad4630_16_chip_info },
+ { "ad4630-24", (kernel_ulong_t)&ad4630_24_chip_info },
{}
};
MODULE_DEVICE_TABLE(spi, ad4030_id_table);

static const struct of_device_id ad4030_of_match[] = {
{ .compatible = "adi,ad4030-24", .data = &ad4030_24_chip_info },
+ { .compatible = "adi,ad4630-16", .data = &ad4630_16_chip_info },
+ { .compatible = "adi,ad4630-24", .data = &ad4630_24_chip_info },
{}
};
MODULE_DEVICE_TABLE(of, ad4030_of_match);

--
2.44.1