// SPDX-License-Identifier: GPL-2.0+ /* * AD7124 SPI ADC driver * * Copyright 2018 Analog Devices Inc. */ #include #include #include #include #include #include #include #include #include #include #include #include #include /* AD7124 registers */ #define AD7124_COMMS 0x00 #define AD7124_STATUS 0x00 #define AD7124_ADC_CONTROL 0x01 #define AD7124_DATA 0x02 #define AD7124_IO_CONTROL_1 0x03 #define AD7124_IO_CONTROL_2 0x04 #define AD7124_ID 0x05 #define AD7124_ERROR 0x06 #define AD7124_ERROR_EN 0x07 #define AD7124_MCLK_COUNT 0x08 #define AD7124_CHANNEL(x) (0x09 + (x)) #define AD7124_CONFIG(x) (0x19 + (x)) #define AD7124_FILTER(x) (0x21 + (x)) #define AD7124_OFFSET(x) (0x29 + (x)) #define AD7124_GAIN(x) (0x31 + (x)) /* AD7124_STATUS */ #define AD7124_STATUS_POR_FLAG_MSK BIT(4) /* AD7124_ADC_CONTROL */ #define AD7124_ADC_CTRL_REF_EN_MSK BIT(8) #define AD7124_ADC_CTRL_REF_EN(x) FIELD_PREP(AD7124_ADC_CTRL_REF_EN_MSK, x) #define AD7124_ADC_CTRL_PWR_MSK GENMASK(7, 6) #define AD7124_ADC_CTRL_PWR(x) FIELD_PREP(AD7124_ADC_CTRL_PWR_MSK, x) #define AD7124_ADC_CTRL_MODE_MSK GENMASK(5, 2) #define AD7124_ADC_CTRL_MODE(x) FIELD_PREP(AD7124_ADC_CTRL_MODE_MSK, x) /* AD7124_CHANNEL_X */ #define AD7124_CHANNEL_EN_MSK BIT(15) #define AD7124_CHANNEL_EN(x) FIELD_PREP(AD7124_CHANNEL_EN_MSK, x) #define AD7124_CHANNEL_SETUP_MSK GENMASK(14, 12) #define AD7124_CHANNEL_SETUP(x) FIELD_PREP(AD7124_CHANNEL_SETUP_MSK, x) #define AD7124_CHANNEL_AINP_MSK GENMASK(9, 5) #define AD7124_CHANNEL_AINP(x) FIELD_PREP(AD7124_CHANNEL_AINP_MSK, x) #define AD7124_CHANNEL_AINM_MSK GENMASK(4, 0) #define AD7124_CHANNEL_AINM(x) FIELD_PREP(AD7124_CHANNEL_AINM_MSK, x) /* AD7124_CONFIG_X */ #define AD7124_CONFIG_BIPOLAR_MSK BIT(11) #define AD7124_CONFIG_BIPOLAR(x) FIELD_PREP(AD7124_CONFIG_BIPOLAR_MSK, x) #define AD7124_CONFIG_REF_SEL_MSK GENMASK(4, 3) #define AD7124_CONFIG_REF_SEL(x) FIELD_PREP(AD7124_CONFIG_REF_SEL_MSK, x) #define AD7124_CONFIG_PGA_MSK GENMASK(2, 0) #define AD7124_CONFIG_PGA(x) FIELD_PREP(AD7124_CONFIG_PGA_MSK, x) #define AD7124_CONFIG_IN_BUFF_MSK GENMASK(7, 6) #define AD7124_CONFIG_IN_BUFF(x) FIELD_PREP(AD7124_CONFIG_IN_BUFF_MSK, x) /* AD7124_FILTER_X */ #define AD7124_FILTER_FS_MSK GENMASK(10, 0) #define AD7124_FILTER_FS(x) FIELD_PREP(AD7124_FILTER_FS_MSK, x) #define AD7124_FILTER_TYPE_MSK GENMASK(23, 21) #define AD7124_FILTER_TYPE_SEL(x) FIELD_PREP(AD7124_FILTER_TYPE_MSK, x) #define AD7124_SINC3_FILTER 2 #define AD7124_SINC4_FILTER 0 enum ad7124_ids { ID_AD7124_4, ID_AD7124_8, }; enum ad7124_ref_sel { AD7124_REFIN1, AD7124_REFIN2, AD7124_INT_REF, AD7124_AVDD_REF, }; enum ad7124_power_mode { AD7124_LOW_POWER, AD7124_MID_POWER, AD7124_FULL_POWER, }; static const unsigned int ad7124_gain[8] = { 1, 2, 4, 8, 16, 32, 64, 128 }; static const int ad7124_master_clk_freq_hz[3] = { [AD7124_LOW_POWER] = 76800, [AD7124_MID_POWER] = 153600, [AD7124_FULL_POWER] = 614400, }; static const char * const ad7124_ref_names[] = { [AD7124_REFIN1] = "refin1", [AD7124_REFIN2] = "refin2", [AD7124_INT_REF] = "int", [AD7124_AVDD_REF] = "avdd", }; struct ad7124_chip_info { unsigned int num_inputs; }; struct ad7124_channel_config { enum ad7124_ref_sel refsel; bool bipolar; bool buf_positive; bool buf_negative; unsigned int ain; unsigned int vref_mv; unsigned int pga_bits; unsigned int odr; unsigned int filter_type; }; struct ad7124_state { const struct ad7124_chip_info *chip_info; struct ad_sigma_delta sd; struct ad7124_channel_config *channel_config; struct regulator *vref[4]; struct clk *mclk; unsigned int adc_control; unsigned int num_channels; }; static const struct iio_chan_spec ad7124_channel_template = { .type = IIO_VOLTAGE, .indexed = 1, .differential = 1, .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE) | BIT(IIO_CHAN_INFO_OFFSET) | BIT(IIO_CHAN_INFO_SAMP_FREQ) | BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY), .scan_type = { .sign = 'u', .realbits = 24, .storagebits = 32, .shift = 8, .endianness = IIO_BE, }, }; static struct ad7124_chip_info ad7124_chip_info_tbl[] = { [ID_AD7124_4] = { .num_inputs = 8, }, [ID_AD7124_8] = { .num_inputs = 16, }, }; static int ad7124_find_closest_match(const int *array, unsigned int size, int val) { int i, idx; unsigned int diff_new, diff_old; diff_old = U32_MAX; idx = 0; for (i = 0; i < size; i++) { diff_new = abs(val - array[i]); if (diff_new < diff_old) { diff_old = diff_new; idx = i; } } return idx; } static int ad7124_spi_write_mask(struct ad7124_state *st, unsigned int addr, unsigned long mask, unsigned int val, unsigned int bytes) { unsigned int readval; int ret; ret = ad_sd_read_reg(&st->sd, addr, bytes, &readval); if (ret < 0) return ret; readval &= ~mask; readval |= val; return ad_sd_write_reg(&st->sd, addr, bytes, readval); } static int ad7124_set_mode(struct ad_sigma_delta *sd, enum ad_sigma_delta_mode mode) { struct ad7124_state *st = container_of(sd, struct ad7124_state, sd); st->adc_control &= ~AD7124_ADC_CTRL_MODE_MSK; st->adc_control |= AD7124_ADC_CTRL_MODE(mode); return ad_sd_write_reg(&st->sd, AD7124_ADC_CONTROL, 2, st->adc_control); } static int ad7124_set_channel(struct ad_sigma_delta *sd, unsigned int channel) { struct ad7124_state *st = container_of(sd, struct ad7124_state, sd); unsigned int val; val = st->channel_config[channel].ain | AD7124_CHANNEL_EN(1) | AD7124_CHANNEL_SETUP(channel); return ad_sd_write_reg(&st->sd, AD7124_CHANNEL(channel), 2, val); } static const struct ad_sigma_delta_info ad7124_sigma_delta_info = { .set_channel = ad7124_set_channel, .set_mode = ad7124_set_mode, .has_registers = true, .addr_shift = 0, .read_mask = BIT(6), .data_reg = AD7124_DATA, .irq_flags = IRQF_TRIGGER_FALLING, }; static int ad7124_set_channel_odr(struct ad7124_state *st, unsigned int channel, unsigned int odr) { unsigned int fclk, odr_sel_bits; int ret; fclk = clk_get_rate(st->mclk); /* * FS[10:0] = fCLK / (fADC x 32) where: * fADC is the output data rate * fCLK is the master clock frequency * FS[10:0] are the bits in the filter register * FS[10:0] can have a value from 1 to 2047 */ odr_sel_bits = DIV_ROUND_CLOSEST(fclk, odr * 32); if (odr_sel_bits < 1) odr_sel_bits = 1; else if (odr_sel_bits > 2047) odr_sel_bits = 2047; ret = ad7124_spi_write_mask(st, AD7124_FILTER(channel), AD7124_FILTER_FS_MSK, AD7124_FILTER_FS(odr_sel_bits), 3); if (ret < 0) return ret; /* fADC = fCLK / (FS[10:0] x 32) */ st->channel_config[channel].odr = DIV_ROUND_CLOSEST(fclk, odr_sel_bits * 32); return 0; } static int ad7124_set_channel_gain(struct ad7124_state *st, unsigned int channel, unsigned int gain) { unsigned int res; int ret; res = ad7124_find_closest_match(ad7124_gain, ARRAY_SIZE(ad7124_gain), gain); ret = ad7124_spi_write_mask(st, AD7124_CONFIG(channel), AD7124_CONFIG_PGA_MSK, AD7124_CONFIG_PGA(res), 2); if (ret < 0) return ret; st->channel_config[channel].pga_bits = res; return 0; } static int ad7124_get_3db_filter_freq(struct ad7124_state *st, unsigned int channel) { unsigned int fadc; fadc = st->channel_config[channel].odr; switch (st->channel_config[channel].filter_type) { case AD7124_SINC3_FILTER: return DIV_ROUND_CLOSEST(fadc * 230, 1000); case AD7124_SINC4_FILTER: return DIV_ROUND_CLOSEST(fadc * 262, 1000); default: return -EINVAL; } } static int ad7124_set_3db_filter_freq(struct ad7124_state *st, unsigned int channel, unsigned int freq) { unsigned int sinc4_3db_odr; unsigned int sinc3_3db_odr; unsigned int new_filter; unsigned int new_odr; sinc4_3db_odr = DIV_ROUND_CLOSEST(freq * 1000, 230); sinc3_3db_odr = DIV_ROUND_CLOSEST(freq * 1000, 262); if (sinc4_3db_odr > sinc3_3db_odr) { new_filter = AD7124_SINC3_FILTER; new_odr = sinc4_3db_odr; } else { new_filter = AD7124_SINC4_FILTER; new_odr = sinc3_3db_odr; } if (st->channel_config[channel].filter_type != new_filter) { int ret; st->channel_config[channel].filter_type = new_filter; ret = ad7124_spi_write_mask(st, AD7124_FILTER(channel), AD7124_FILTER_TYPE_MSK, AD7124_FILTER_TYPE_SEL(new_filter), 3); if (ret < 0) return ret; } return ad7124_set_channel_odr(st, channel, new_odr); } static int ad7124_read_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int *val, int *val2, long info) { struct ad7124_state *st = iio_priv(indio_dev); int idx, ret; switch (info) { case IIO_CHAN_INFO_RAW: ret = ad_sigma_delta_single_conversion(indio_dev, chan, val); if (ret < 0) return ret; /* After the conversion is performed, disable the channel */ ret = ad_sd_write_reg(&st->sd, AD7124_CHANNEL(chan->address), 2, st->channel_config[chan->address].ain | AD7124_CHANNEL_EN(0)); if (ret < 0) return ret; return IIO_VAL_INT; case IIO_CHAN_INFO_SCALE: idx = st->channel_config[chan->address].pga_bits; *val = st->channel_config[chan->address].vref_mv; if (st->channel_config[chan->address].bipolar) *val2 = chan->scan_type.realbits - 1 + idx; else *val2 = chan->scan_type.realbits + idx; return IIO_VAL_FRACTIONAL_LOG2; case IIO_CHAN_INFO_OFFSET: if (st->channel_config[chan->address].bipolar) *val = -(1 << (chan->scan_type.realbits - 1)); else *val = 0; return IIO_VAL_INT; case IIO_CHAN_INFO_SAMP_FREQ: *val = st->channel_config[chan->address].odr; return IIO_VAL_INT; case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY: *val = ad7124_get_3db_filter_freq(st, chan->scan_index); return IIO_VAL_INT; default: return -EINVAL; } } static int ad7124_write_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int val, int val2, long info) { struct ad7124_state *st = iio_priv(indio_dev); unsigned int res, gain, full_scale, vref; switch (info) { case IIO_CHAN_INFO_SAMP_FREQ: if (val2 != 0) return -EINVAL; return ad7124_set_channel_odr(st, chan->address, val); case IIO_CHAN_INFO_SCALE: if (val != 0) return -EINVAL; if (st->channel_config[chan->address].bipolar) full_scale = 1 << (chan->scan_type.realbits - 1); else full_scale = 1 << chan->scan_type.realbits; vref = st->channel_config[chan->address].vref_mv * 1000000LL; res = DIV_ROUND_CLOSEST(vref, full_scale); gain = DIV_ROUND_CLOSEST(res, val2); return ad7124_set_channel_gain(st, chan->address, gain); case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY: if (val2 != 0) return -EINVAL; return ad7124_set_3db_filter_freq(st, chan->address, val); default: return -EINVAL; } } static IIO_CONST_ATTR(in_voltage_scale_available, "0.000001164 0.000002328 0.000004656 0.000009313 0.000018626 0.000037252 0.000074505 0.000149011 0.000298023"); static struct attribute *ad7124_attributes[] = { &iio_const_attr_in_voltage_scale_available.dev_attr.attr, NULL, }; static const struct attribute_group ad7124_attrs_group = { .attrs = ad7124_attributes, }; static const struct iio_info ad7124_info = { .read_raw = ad7124_read_raw, .write_raw = ad7124_write_raw, .validate_trigger = ad_sd_validate_trigger, .attrs = &ad7124_attrs_group, }; static int ad7124_soft_reset(struct ad7124_state *st) { unsigned int readval, timeout; int ret; ret = ad_sd_reset(&st->sd, 64); if (ret < 0) return ret; timeout = 100; do { ret = ad_sd_read_reg(&st->sd, AD7124_STATUS, 1, &readval); if (ret < 0) return ret; if (!(readval & AD7124_STATUS_POR_FLAG_MSK)) return 0; /* The AD7124 requires typically 2ms to power up and settle */ usleep_range(100, 2000); } while (--timeout); dev_err(&st->sd.spi->dev, "Soft reset failed\n"); return -EIO; } static int ad7124_init_channel_vref(struct ad7124_state *st, unsigned int channel_number) { unsigned int refsel = st->channel_config[channel_number].refsel; switch (refsel) { case AD7124_REFIN1: case AD7124_REFIN2: case AD7124_AVDD_REF: if (IS_ERR(st->vref[refsel])) { dev_err(&st->sd.spi->dev, "Error, trying to use external voltage reference without a %s regulator.\n", ad7124_ref_names[refsel]); return PTR_ERR(st->vref[refsel]); } st->channel_config[channel_number].vref_mv = regulator_get_voltage(st->vref[refsel]); /* Conversion from uV to mV */ st->channel_config[channel_number].vref_mv /= 1000; break; case AD7124_INT_REF: st->channel_config[channel_number].vref_mv = 2500; st->adc_control &= ~AD7124_ADC_CTRL_REF_EN_MSK; st->adc_control |= AD7124_ADC_CTRL_REF_EN(1); return ad_sd_write_reg(&st->sd, AD7124_ADC_CONTROL, 2, st->adc_control); default: dev_err(&st->sd.spi->dev, "Invalid reference %d\n", refsel); return -EINVAL; } return 0; } static int ad7124_of_parse_channel_config(struct iio_dev *indio_dev, struct device_node *np) { struct ad7124_state *st = iio_priv(indio_dev); struct device_node *child; struct iio_chan_spec *chan; struct ad7124_channel_config *chan_config; unsigned int ain[2], channel = 0, tmp; int ret; st->num_channels = of_get_available_child_count(np); if (!st->num_channels) { dev_err(indio_dev->dev.parent, "no channel children\n"); return -ENODEV; } chan = devm_kcalloc(indio_dev->dev.parent, st->num_channels, sizeof(*chan), GFP_KERNEL); if (!chan) return -ENOMEM; chan_config = devm_kcalloc(indio_dev->dev.parent, st->num_channels, sizeof(*chan_config), GFP_KERNEL); if (!chan_config) return -ENOMEM; indio_dev->channels = chan; indio_dev->num_channels = st->num_channels; st->channel_config = chan_config; for_each_available_child_of_node(np, child) { ret = of_property_read_u32(child, "reg", &channel); if (ret) goto err; ret = of_property_read_u32_array(child, "diff-channels", ain, 2); if (ret) goto err; st->channel_config[channel].ain = AD7124_CHANNEL_AINP(ain[0]) | AD7124_CHANNEL_AINM(ain[1]); st->channel_config[channel].bipolar = of_property_read_bool(child, "bipolar"); ret = of_property_read_u32(child, "adi,reference-select", &tmp); if (ret) st->channel_config[channel].refsel = AD7124_INT_REF; else st->channel_config[channel].refsel = tmp; st->channel_config[channel].buf_positive = of_property_read_bool(child, "adi,buffered-positive"); st->channel_config[channel].buf_negative = of_property_read_bool(child, "adi,buffered-negative"); chan[channel] = ad7124_channel_template; chan[channel].address = channel; chan[channel].scan_index = channel; chan[channel].channel = ain[0]; chan[channel].channel2 = ain[1]; } return 0; err: of_node_put(child); return ret; } static int ad7124_setup(struct ad7124_state *st) { unsigned int val, fclk, power_mode; int i, ret, tmp; fclk = clk_get_rate(st->mclk); if (!fclk) return -EINVAL; /* The power mode changes the master clock frequency */ power_mode = ad7124_find_closest_match(ad7124_master_clk_freq_hz, ARRAY_SIZE(ad7124_master_clk_freq_hz), fclk); if (fclk != ad7124_master_clk_freq_hz[power_mode]) { ret = clk_set_rate(st->mclk, fclk); if (ret) return ret; } /* Set the power mode */ st->adc_control &= ~AD7124_ADC_CTRL_PWR_MSK; st->adc_control |= AD7124_ADC_CTRL_PWR(power_mode); ret = ad_sd_write_reg(&st->sd, AD7124_ADC_CONTROL, 2, st->adc_control); if (ret < 0) return ret; for (i = 0; i < st->num_channels; i++) { val = st->channel_config[i].ain | AD7124_CHANNEL_SETUP(i); ret = ad_sd_write_reg(&st->sd, AD7124_CHANNEL(i), 2, val); if (ret < 0) return ret; ret = ad7124_init_channel_vref(st, i); if (ret < 0) return ret; tmp = (st->channel_config[i].buf_positive << 1) + st->channel_config[i].buf_negative; val = AD7124_CONFIG_BIPOLAR(st->channel_config[i].bipolar) | AD7124_CONFIG_REF_SEL(st->channel_config[i].refsel) | AD7124_CONFIG_IN_BUFF(tmp); ret = ad_sd_write_reg(&st->sd, AD7124_CONFIG(i), 2, val); if (ret < 0) return ret; /* * 9.38 SPS is the minimum output data rate supported * regardless of the selected power mode. Round it up to 10 and * set all the enabled channels to this default value. */ ret = ad7124_set_channel_odr(st, i, 10); } return ret; } static int ad7124_probe(struct spi_device *spi) { const struct spi_device_id *id; struct ad7124_state *st; struct iio_dev *indio_dev; int i, ret; indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st)); if (!indio_dev) return -ENOMEM; st = iio_priv(indio_dev); id = spi_get_device_id(spi); st->chip_info = &ad7124_chip_info_tbl[id->driver_data]; ad_sd_init(&st->sd, indio_dev, spi, &ad7124_sigma_delta_info); spi_set_drvdata(spi, indio_dev); indio_dev->dev.parent = &spi->dev; indio_dev->name = spi_get_device_id(spi)->name; indio_dev->modes = INDIO_DIRECT_MODE; indio_dev->info = &ad7124_info; ret = ad7124_of_parse_channel_config(indio_dev, spi->dev.of_node); if (ret < 0) return ret; for (i = 0; i < ARRAY_SIZE(st->vref); i++) { if (i == AD7124_INT_REF) continue; st->vref[i] = devm_regulator_get_optional(&spi->dev, ad7124_ref_names[i]); if (PTR_ERR(st->vref[i]) == -ENODEV) continue; else if (IS_ERR(st->vref[i])) return PTR_ERR(st->vref[i]); ret = regulator_enable(st->vref[i]); if (ret) return ret; } st->mclk = devm_clk_get(&spi->dev, "mclk"); if (IS_ERR(st->mclk)) { ret = PTR_ERR(st->mclk); goto error_regulator_disable; } ret = clk_prepare_enable(st->mclk); if (ret < 0) goto error_regulator_disable; ret = ad7124_soft_reset(st); if (ret < 0) goto error_clk_disable_unprepare; ret = ad7124_setup(st); if (ret < 0) goto error_clk_disable_unprepare; ret = ad_sd_setup_buffer_and_trigger(indio_dev); if (ret < 0) goto error_clk_disable_unprepare; ret = iio_device_register(indio_dev); if (ret < 0) { dev_err(&spi->dev, "Failed to register iio device\n"); goto error_remove_trigger; } return 0; error_remove_trigger: ad_sd_cleanup_buffer_and_trigger(indio_dev); error_clk_disable_unprepare: clk_disable_unprepare(st->mclk); error_regulator_disable: for (i = ARRAY_SIZE(st->vref) - 1; i >= 0; i--) { if (!IS_ERR_OR_NULL(st->vref[i])) regulator_disable(st->vref[i]); } return ret; } static int ad7124_remove(struct spi_device *spi) { struct iio_dev *indio_dev = spi_get_drvdata(spi); struct ad7124_state *st = iio_priv(indio_dev); int i; iio_device_unregister(indio_dev); ad_sd_cleanup_buffer_and_trigger(indio_dev); clk_disable_unprepare(st->mclk); for (i = ARRAY_SIZE(st->vref) - 1; i >= 0; i--) { if (!IS_ERR_OR_NULL(st->vref[i])) regulator_disable(st->vref[i]); } return 0; } static const struct spi_device_id ad7124_id_table[] = { { "ad7124-4", ID_AD7124_4 }, { "ad7124-8", ID_AD7124_8 }, {} }; MODULE_DEVICE_TABLE(spi, ad7124_id_table); static const struct of_device_id ad7124_of_match[] = { { .compatible = "adi,ad7124-4" }, { .compatible = "adi,ad7124-8" }, { }, }; MODULE_DEVICE_TABLE(of, ad7124_of_match); static struct spi_driver ad71124_driver = { .driver = { .name = "ad7124", .of_match_table = ad7124_of_match, }, .probe = ad7124_probe, .remove = ad7124_remove, .id_table = ad7124_id_table, }; module_spi_driver(ad71124_driver); MODULE_AUTHOR("Stefan Popa "); MODULE_DESCRIPTION("Analog Devices AD7124 SPI driver"); MODULE_LICENSE("GPL");