From: Marcelo Schmitt Date: Mon, 23 Feb 2026 17:10:23 +0000 (-0300) Subject: iio: adc: ad4030: Add support for ADAQ4216 and ADAQ4224 X-Git-Tag: v7.1-rc1~17^2~120^2~128 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=185f7b6cee61a2c764e6a5026f5c0dc57e14277a;p=thirdparty%2Flinux.git iio: adc: ad4030: Add support for ADAQ4216 and ADAQ4224 ADAQ4216 and ADAQ4224 are similar to AD4030, but feature a PGA circuitry that scales the analog input signal prior to it reaching the ADC. The PGA is controlled through a pair of pins (A0 and A1) whose state define the gain that is applied to the input signal. Add support for ADAQ4216 and ADAQ4224. Provide a list of PGA options through the IIO device channel scale available interface and enable control of the PGA through the channel scale interface. Signed-off-by: Marcelo Schmitt Signed-off-by: Jonathan Cameron --- diff --git a/drivers/iio/adc/ad4030.c b/drivers/iio/adc/ad4030.c index 42b8cd8873827..9c5f19321e3b8 100644 --- a/drivers/iio/adc/ad4030.c +++ b/drivers/iio/adc/ad4030.c @@ -48,6 +48,8 @@ #define AD4030_REG_CHIP_GRADE_AD4630_24_GRADE 0x00 #define AD4030_REG_CHIP_GRADE_AD4632_16_GRADE 0x05 #define AD4030_REG_CHIP_GRADE_AD4632_24_GRADE 0x02 +#define AD4030_REG_CHIP_GRADE_ADAQ4216_GRADE 0x1E +#define AD4030_REG_CHIP_GRADE_ADAQ4224_GRADE 0x1C #define AD4030_REG_CHIP_GRADE_MASK_CHIP_GRADE GENMASK(7, 3) #define AD4030_REG_SCRATCH_PAD 0x0A #define AD4030_REG_SPI_REVISION 0x0B @@ -125,6 +127,10 @@ /* Datasheet says 9.8ns, so use the closest integer value */ #define AD4030_TQUIET_CNV_DELAY_NS 10 +/* HARDWARE_GAIN */ +#define ADAQ4616_PGA_PINS 2 +#define ADAQ4616_PGA_GAIN_MAX_NANO (NANO * 2 / 3) + enum ad4030_out_mode { AD4030_OUT_DATA_MD_DIFF, AD4030_OUT_DATA_MD_16_DIFF_8_COM, @@ -145,6 +151,23 @@ enum { AD4030_SCAN_TYPE_AVG, }; +/* + * Gains computed as fractions of 1000 so they can be expressed by integers. + */ +static const int adaq4216_hw_gains_vpv[] = { + 1 * MILLI / 3, /* 0.333 */ + 5 * MILLI / 9, /* 0.555 */ + 20 * MILLI / 9, /* 0.2222 */ + 20 * MILLI / 3, /* 0.6666 */ +}; + +static const int adaq4216_hw_gains_frac[][2] = { + { 1, 3 }, /* 1/3 V/V gain */ + { 5, 9 }, /* 5/9 V/V gain */ + { 20, 9 }, /* 20/9 V/V gain */ + { 20, 3 }, /* 20/3 V/V gain */ +}; + struct ad4030_chip_info { const char *name; const unsigned long *available_masks; @@ -152,6 +175,7 @@ struct ad4030_chip_info { const struct iio_chan_spec offload_channels[AD4030_MAX_IIO_CHANNEL_NB]; u8 grade; u8 precision_bits; + bool has_pga; /* Number of hardware channels */ int num_voltage_inputs; unsigned int tcyc_ns; @@ -175,7 +199,11 @@ struct ad4030_state { struct spi_offload_trigger *offload_trigger; struct spi_offload_trigger_config offload_trigger_config; struct pwm_device *cnv_trigger; + size_t scale_avail_size; struct pwm_waveform cnv_wf; + unsigned int scale_avail[ARRAY_SIZE(adaq4216_hw_gains_vpv)][2]; + struct gpio_descs *pga_gpios; + unsigned int pga_index; /* * DMA (thus cache coherency maintenance) requires the transfer buffers @@ -232,7 +260,7 @@ struct ad4030_state { * - voltage0-voltage1 * - voltage2-voltage3 */ -#define __AD4030_CHAN_DIFF(_idx, _scan_type, _offload) { \ +#define __AD4030_CHAN_DIFF(_idx, _scan_type, _offload, _pga) { \ .info_mask_shared_by_all = \ (_offload ? BIT(IIO_CHAN_INFO_SAMP_FREQ) : 0) | \ BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), \ @@ -243,6 +271,7 @@ struct ad4030_state { BIT(IIO_CHAN_INFO_CALIBBIAS) | \ BIT(IIO_CHAN_INFO_RAW), \ .info_mask_separate_available = BIT(IIO_CHAN_INFO_CALIBBIAS) | \ + (_pga ? BIT(IIO_CHAN_INFO_SCALE) : 0) | \ BIT(IIO_CHAN_INFO_CALIBSCALE), \ .type = IIO_VOLTAGE, \ .indexed = 1, \ @@ -257,10 +286,16 @@ struct ad4030_state { } #define AD4030_CHAN_DIFF(_idx, _scan_type) \ - __AD4030_CHAN_DIFF(_idx, _scan_type, 0) + __AD4030_CHAN_DIFF(_idx, _scan_type, 0, 0) #define AD4030_OFFLOAD_CHAN_DIFF(_idx, _scan_type) \ - __AD4030_CHAN_DIFF(_idx, _scan_type, 1) + __AD4030_CHAN_DIFF(_idx, _scan_type, 1, 0) + +#define ADAQ4216_CHAN_DIFF(_idx, _scan_type) \ + __AD4030_CHAN_DIFF(_idx, _scan_type, 0, 1) + +#define ADAQ4216_OFFLOAD_CHAN_DIFF(_idx, _scan_type) \ + __AD4030_CHAN_DIFF(_idx, _scan_type, 1, 1) /* * AD4030 can average over 2^N samples, where N = 1, 2, 3, ..., 16. @@ -418,6 +453,65 @@ static const struct regmap_config ad4030_regmap_config = { .max_register = AD4030_REG_DIG_ERR, }; +static void ad4030_fill_scale_avail(struct ad4030_state *st) +{ + unsigned int mag_bits, int_part, fract_part; + u64 range; + + /* + * The maximum precision of differential channels is retrieved from the + * chip properties. The output code of differential channels is in two's + * complement format (i.e. signed), so the MSB is the sign bit and only + * (precision_bits - 1) bits express voltage magnitude. + */ + mag_bits = st->chip->precision_bits - 1; + + for (unsigned int i = 0; i < ARRAY_SIZE(adaq4216_hw_gains_frac); i++) { + range = mult_frac(st->vref_uv, adaq4216_hw_gains_frac[i][1], + adaq4216_hw_gains_frac[i][0]); + /* + * If range were in mV, we would multiply it by NANO below. + * Though, range is in µV so multiply it by MICRO only so the + * result after right shift and division scales output codes to + * millivolts. + */ + int_part = div_u64_rem((range * MICRO) >> mag_bits, NANO, &fract_part); + st->scale_avail[i][0] = int_part; + st->scale_avail[i][1] = fract_part; + } +} + +static int ad4030_set_pga_gain(struct ad4030_state *st) +{ + DECLARE_BITMAP(bitmap, ADAQ4616_PGA_PINS) = { }; + + bitmap_write(bitmap, st->pga_index, 0, ADAQ4616_PGA_PINS); + + return gpiod_multi_set_value_cansleep(st->pga_gpios, bitmap); +} + +static int ad4030_set_pga(struct iio_dev *indio_dev, int gain_int, int gain_fract) +{ + struct ad4030_state *st = iio_priv(indio_dev); + unsigned int mag_bits = st->chip->precision_bits - 1; + unsigned int tmp; + u64 gain_nano; + + if (!st->pga_gpios) + return -EINVAL; + + gain_nano = gain_int * NANO + gain_fract; + if (!in_range(gain_nano, 1, ADAQ4616_PGA_GAIN_MAX_NANO)) + return -EINVAL; + + tmp = DIV_ROUND_CLOSEST_ULL(gain_nano << mag_bits, NANO); + gain_nano = DIV_ROUND_CLOSEST(st->vref_uv, tmp); + st->pga_index = find_closest(gain_nano, adaq4216_hw_gains_vpv, + ARRAY_SIZE(adaq4216_hw_gains_vpv)); + + return ad4030_set_pga_gain(st); +} + static int ad4030_get_chan_scale(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int *val, @@ -430,6 +524,13 @@ static int ad4030_get_chan_scale(struct iio_dev *indio_dev, if (IS_ERR(scan_type)) return PTR_ERR(scan_type); + /* The LSB of the 8-bit common-mode data is always vref/256. */ + if (st->chip->has_pga && scan_type->realbits != 8) { + *val = st->scale_avail[st->pga_index][0]; + *val2 = st->scale_avail[st->pga_index][1]; + return IIO_VAL_INT_PLUS_NANO; + } + if (chan->differential) *val = (st->vref_uv * 2) / MILLI; else @@ -898,6 +999,15 @@ static int ad4030_read_avail(struct iio_dev *indio_dev, *length = ARRAY_SIZE(ad4030_average_modes); return IIO_AVAIL_LIST; + case IIO_CHAN_INFO_SCALE: + if (st->scale_avail_size == 1) + *vals = (int *)st->scale_avail[st->pga_index]; + else + *vals = (int *)st->scale_avail; + *length = st->scale_avail_size * 2; /* print int and nano part */ + *type = IIO_VAL_INT_PLUS_NANO; + return IIO_AVAIL_LIST; + default: return -EINVAL; } @@ -970,6 +1080,9 @@ static int ad4030_write_raw_dispatch(struct iio_dev *indio_dev, case IIO_CHAN_INFO_SAMP_FREQ: return ad4030_set_sampling_freq(indio_dev, val); + case IIO_CHAN_INFO_SCALE: + return ad4030_set_pga(indio_dev, val, val2); + default: return -EINVAL; } @@ -991,6 +1104,17 @@ static int ad4030_write_raw(struct iio_dev *indio_dev, return ret; } +static int ad4030_write_raw_get_fmt(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, long mask) +{ + switch (mask) { + case IIO_CHAN_INFO_SCALE: + return IIO_VAL_INT_PLUS_NANO; + default: + return IIO_VAL_INT_PLUS_MICRO; + } +} + static int ad4030_reg_access(struct iio_dev *indio_dev, unsigned int reg, unsigned int writeval, unsigned int *readval) { @@ -1037,6 +1161,7 @@ static const struct iio_info ad4030_iio_info = { .read_avail = ad4030_read_avail, .read_raw = ad4030_read_raw, .write_raw = ad4030_write_raw, + .write_raw_get_fmt = &ad4030_write_raw_get_fmt, .debugfs_reg_access = ad4030_reg_access, .read_label = ad4030_read_label, .get_current_scan_type = ad4030_get_current_scan_type, @@ -1278,6 +1403,26 @@ static int ad4030_spi_offload_setup(struct iio_dev *indio_dev, IIO_BUFFER_DIRECTION_IN); } +static int ad4030_setup_pga(struct device *dev, struct iio_dev *indio_dev, + struct ad4030_state *st) +{ + /* Setup GPIOs for PGA control */ + st->pga_gpios = devm_gpiod_get_array(dev, "pga", GPIOD_OUT_LOW); + if (IS_ERR(st->pga_gpios)) + return dev_err_probe(dev, PTR_ERR(st->pga_gpios), + "Failed to get PGA gpios.\n"); + + if (st->pga_gpios->ndescs != ADAQ4616_PGA_PINS) + return dev_err_probe(dev, -EINVAL, + "Expected %d GPIOs for PGA control.\n", + ADAQ4616_PGA_PINS); + + st->scale_avail_size = ARRAY_SIZE(adaq4216_hw_gains_vpv); + st->pga_index = 0; + + return 0; +} + static int ad4030_probe(struct spi_device *spi) { struct device *dev = &spi->dev; @@ -1320,6 +1465,14 @@ static int ad4030_probe(struct spi_device *spi) if (ret) return ret; + if (st->chip->has_pga) { + ret = ad4030_setup_pga(dev, indio_dev, st); + if (ret) + return ret; + + ad4030_fill_scale_avail(st); + } + ret = ad4030_config(st); if (ret) return ret; @@ -1571,12 +1724,52 @@ static const struct ad4030_chip_info ad4632_24_chip_info = { .max_sample_rate_hz = 500 * HZ_PER_KHZ, }; +static const struct ad4030_chip_info adaq4216_chip_info = { + .name = "adaq4216", + .available_masks = ad4030_channel_masks, + .channels = { + ADAQ4216_CHAN_DIFF(0, ad4030_16_scan_types), + AD4030_CHAN_CMO(1, 0), + IIO_CHAN_SOFT_TIMESTAMP(2), + }, + .offload_channels = { + ADAQ4216_OFFLOAD_CHAN_DIFF(0, ad4030_16_offload_scan_types), + }, + .grade = AD4030_REG_CHIP_GRADE_ADAQ4216_GRADE, + .precision_bits = 16, + .has_pga = true, + .num_voltage_inputs = 1, + .tcyc_ns = AD4030_TCYC_ADJUSTED_NS, + .max_sample_rate_hz = 2 * HZ_PER_MHZ, +}; + +static const struct ad4030_chip_info adaq4224_chip_info = { + .name = "adaq4224", + .available_masks = ad4030_channel_masks, + .channels = { + ADAQ4216_CHAN_DIFF(0, ad4030_24_scan_types), + AD4030_CHAN_CMO(1, 0), + IIO_CHAN_SOFT_TIMESTAMP(2), + }, + .offload_channels = { + ADAQ4216_OFFLOAD_CHAN_DIFF(0, ad4030_24_offload_scan_types), + }, + .grade = AD4030_REG_CHIP_GRADE_ADAQ4224_GRADE, + .precision_bits = 24, + .has_pga = true, + .num_voltage_inputs = 1, + .tcyc_ns = AD4030_TCYC_ADJUSTED_NS, + .max_sample_rate_hz = 2 * HZ_PER_MHZ, +}; + 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 }, { "ad4632-16", (kernel_ulong_t)&ad4632_16_chip_info }, { "ad4632-24", (kernel_ulong_t)&ad4632_24_chip_info }, + { "adaq4216", (kernel_ulong_t)&adaq4216_chip_info }, + { "adaq4224", (kernel_ulong_t)&adaq4224_chip_info }, { } }; MODULE_DEVICE_TABLE(spi, ad4030_id_table); @@ -1587,6 +1780,8 @@ static const struct of_device_id ad4030_of_match[] = { { .compatible = "adi,ad4630-24", .data = &ad4630_24_chip_info }, { .compatible = "adi,ad4632-16", .data = &ad4632_16_chip_info }, { .compatible = "adi,ad4632-24", .data = &ad4632_24_chip_info }, + { .compatible = "adi,adaq4216", .data = &adaq4216_chip_info }, + { .compatible = "adi,adaq4224", .data = &adaq4224_chip_info }, { } }; MODULE_DEVICE_TABLE(of, ad4030_of_match);