From: David Lechner <dlechner@xxxxxxxxxxxx> Add support for AD7383, AD7384 pseudo-differential compatible parts. Pseudo differential parts require common mode voltage supplies so add the support for them and add the support of IIO_CHAN_INFO_OFFSET to retrieve the offset Signed-off-by: David Lechner <dlechner@xxxxxxxxxxxx> Signed-off-by: Julien Stephan <jstephan@xxxxxxxxxxxx> --- drivers/iio/adc/ad7380.c | 110 ++++++++++++++++++++++++++++++++++++++++------- 1 file changed, 94 insertions(+), 16 deletions(-) diff --git a/drivers/iio/adc/ad7380.c b/drivers/iio/adc/ad7380.c index dac7e11755ff..4ad283cf970d 100644 --- a/drivers/iio/adc/ad7380.c +++ b/drivers/iio/adc/ad7380.c @@ -7,6 +7,7 @@ * * Datasheets of supported parts: * ad7380/1 : https://www.analog.com/media/en/technical-documentation/data-sheets/AD7380-7381.pdf + * ad7383/4 : https://www.analog.com/media/en/technical-documentation/data-sheets/ad7383-7384.pdf */ #include <linux/bitfield.h> @@ -66,16 +67,19 @@ struct ad7380_chip_info { const char *name; const struct iio_chan_spec *channels; unsigned int num_channels; + const char * const *vcm_supplies; + unsigned int num_vcm_supplies; }; -#define AD7380_CHANNEL(index, bits) { \ +#define AD7380_CHANNEL(index, bits, diff) { \ .type = IIO_VOLTAGE, \ - .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \ + ((diff) ? 0 : BIT(IIO_CHAN_INFO_OFFSET)), \ .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \ .indexed = 1, \ - .differential = 1, \ - .channel = 2 * (index), \ - .channel2 = 2 * (index) + 1, \ + .differential = (diff), \ + .channel = (diff) ? (2 * (index)) : (index), \ + .channel2 = (diff) ? (2 * (index) + 1) : 0, \ .scan_index = (index), \ .scan_type = { \ .sign = 's', \ @@ -85,15 +89,23 @@ struct ad7380_chip_info { }, \ } -#define DEFINE_AD7380_2_CHANNEL(name, bits) \ -static const struct iio_chan_spec name[] = { \ - AD7380_CHANNEL(0, bits), \ - AD7380_CHANNEL(1, bits), \ - IIO_CHAN_SOFT_TIMESTAMP(2), \ +#define DEFINE_AD7380_2_CHANNEL(name, bits, diff) \ +static const struct iio_chan_spec name[] = { \ + AD7380_CHANNEL(0, bits, diff), \ + AD7380_CHANNEL(1, bits, diff), \ + IIO_CHAN_SOFT_TIMESTAMP(2), \ } -DEFINE_AD7380_2_CHANNEL(ad7380_channels, 16); -DEFINE_AD7380_2_CHANNEL(ad7381_channels, 14); +/* fully differential */ +DEFINE_AD7380_2_CHANNEL(ad7380_channels, 16, 1); +DEFINE_AD7380_2_CHANNEL(ad7381_channels, 14, 1); +/* pseudo differential */ +DEFINE_AD7380_2_CHANNEL(ad7383_channels, 16, 0); +DEFINE_AD7380_2_CHANNEL(ad7384_channels, 14, 0); + +static const char * const ad7380_2_channel_vcm_supplies[] = { + "aina", "ainb", +}; /* Since this is simultaneous sampling, we don't allow individual channels. */ static const unsigned long ad7380_2_channel_scan_masks[] = { @@ -113,11 +125,28 @@ static const struct ad7380_chip_info ad7381_chip_info = { .num_channels = ARRAY_SIZE(ad7381_channels), }; +static const struct ad7380_chip_info ad7383_chip_info = { + .name = "ad7383", + .channels = ad7383_channels, + .num_channels = ARRAY_SIZE(ad7383_channels), + .vcm_supplies = ad7380_2_channel_vcm_supplies, + .num_vcm_supplies = ARRAY_SIZE(ad7380_2_channel_vcm_supplies), +}; + +static const struct ad7380_chip_info ad7384_chip_info = { + .name = "ad7384", + .channels = ad7384_channels, + .num_channels = ARRAY_SIZE(ad7384_channels), + .vcm_supplies = ad7380_2_channel_vcm_supplies, + .num_vcm_supplies = ARRAY_SIZE(ad7380_2_channel_vcm_supplies), +}; + struct ad7380_state { const struct ad7380_chip_info *chip_info; struct spi_device *spi; struct regmap *regmap; unsigned int vref_mv; + unsigned int vcm_mv[2]; /* * DMA (thus cache coherency maintenance) requires the * transfer buffers to live in their own cache lines. @@ -288,13 +317,24 @@ static int ad7380_read_raw(struct iio_dev *indio_dev, unreachable(); case IIO_CHAN_INFO_SCALE: /* - * According to the datasheet, the LSB size for fully differential ADC is - * (2 × VREF) / 2^N, where N is the ADC resolution (i.e realbits) + * According to the datasheet, the LSB size is: + * * (2 × VREF) / 2^N, for differential chips + * * VREF / 2^N, for pseudo-differential chips + * where N is the ADC resolution (i.e realbits) */ *val = st->vref_mv; - *val2 = chan->scan_type.realbits - 1; + *val2 = chan->scan_type.realbits - chan->differential; return IIO_VAL_FRACTIONAL_LOG2; + case IIO_CHAN_INFO_OFFSET: + /* + * According to IIO ABI, offset is applied before scale, + * so offset is: vcm_mv / scale + */ + *val = st->vcm_mv[chan->channel] * (1 << chan->scan_type.realbits) + / st->vref_mv; + + return IIO_VAL_INT; default: return -EINVAL; } @@ -341,7 +381,7 @@ static int ad7380_probe(struct spi_device *spi) struct iio_dev *indio_dev; struct ad7380_state *st; struct regulator *vref; - int ret; + int ret, i; indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st)); if (!indio_dev) @@ -385,6 +425,40 @@ static int ad7380_probe(struct spi_device *spi) st->vref_mv = AD7380_INTERNAL_REF_MV; } + if (st->chip_info->num_vcm_supplies > ARRAY_SIZE(st->vcm_mv)) + return dev_err_probe(&spi->dev, -EINVAL, + "invalid number of VCM supplies\n"); + + /* + * pseudo-differential chips have common mode supplies for the negative + * input pin. + */ + for (i = 0; i < st->chip_info->num_vcm_supplies; i++) { + struct regulator *vcm; + + vcm = devm_regulator_get(&spi->dev, + st->chip_info->vcm_supplies[i]); + if (IS_ERR(vcm)) + return dev_err_probe(&spi->dev, PTR_ERR(vcm), + "Failed to get %s regulator\n", + st->chip_info->vcm_supplies[i]); + + ret = regulator_enable(vcm); + if (ret) + return ret; + + ret = devm_add_action_or_reset(&spi->dev, + ad7380_regulator_disable, vcm); + if (ret) + return ret; + + ret = regulator_get_voltage(vcm); + if (ret < 0) + return ret; + + st->vcm_mv[i] = ret / 1000; + } + st->regmap = devm_regmap_init(&spi->dev, NULL, st, &ad7380_regmap_config); if (IS_ERR(st->regmap)) return dev_err_probe(&spi->dev, PTR_ERR(st->regmap), @@ -413,12 +487,16 @@ static int ad7380_probe(struct spi_device *spi) static const struct of_device_id ad7380_of_match_table[] = { { .compatible = "adi,ad7380", .data = &ad7380_chip_info }, { .compatible = "adi,ad7381", .data = &ad7381_chip_info }, + { .compatible = "adi,ad7383", .data = &ad7383_chip_info }, + { .compatible = "adi,ad7384", .data = &ad7384_chip_info }, { } }; static const struct spi_device_id ad7380_id_table[] = { { "ad7380", (kernel_ulong_t)&ad7380_chip_info }, { "ad7381", (kernel_ulong_t)&ad7381_chip_info }, + { "ad7383", (kernel_ulong_t)&ad7383_chip_info }, + { "ad7384", (kernel_ulong_t)&ad7384_chip_info }, { } }; MODULE_DEVICE_TABLE(spi, ad7380_id_table); -- 2.44.0
