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iio: adc: ad7173: add openwire detection support for single conversions
Some chips of the ad7173 family supports open wire detection. Generate a level fault event whenever an external source is disconnected from the system input on single conversions. Reviewed-by: Nuno Sa <nuno.sa@analog.com> Signed-off-by: Guillaume Ranquet <granquet@baylibre.com> Reviewed-by: David Lechner <dlechner@baylibre.com> Link: https://patch.msgid.link/20250127-ad4111_openwire-v5-2-ef2db05c384f@baylibre.com Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
This commit is contained in:
Guillaume Ranquet
Jonathan Cameron
parent
34934d7996
commit
7530ed2aaa
1 changed files with 179 additions and 0 deletions
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@ -35,6 +35,7 @@
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#include <linux/units.h>
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#include <linux/iio/buffer.h>
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#include <linux/iio/events.h>
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#include <linux/iio/iio.h>
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#include <linux/iio/trigger_consumer.h>
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#include <linux/iio/triggered_buffer.h>
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@ -102,6 +103,7 @@
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#define AD7173_GPIO_PDSW BIT(14)
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#define AD7173_GPIO_OP_EN2_3 BIT(13)
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#define AD4111_GPIO_GP_OW_EN BIT(12)
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#define AD7173_GPIO_MUX_IO BIT(12)
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#define AD7173_GPIO_SYNC_EN BIT(11)
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#define AD7173_GPIO_ERR_EN BIT(10)
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@ -149,6 +151,7 @@
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#define AD7173_FILTER_ODR0_MASK GENMASK(5, 0)
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#define AD7173_MAX_CONFIGS 8
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#define AD4111_OW_DET_THRSH_MV 300
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#define AD7173_MODE_CAL_INT_ZERO 0x4 /* Internal Zero-Scale Calibration */
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#define AD7173_MODE_CAL_INT_FULL 0x5 /* Internal Full-Scale Calibration */
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@ -182,11 +185,15 @@ struct ad7173_device_info {
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bool has_int_ref;
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bool has_ref2;
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bool has_internal_fs_calibration;
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bool has_openwire_det;
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bool higher_gpio_bits;
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u8 num_gpios;
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};
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struct ad7173_channel_config {
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/* Openwire detection threshold */
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unsigned int openwire_thrsh_raw;
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int openwire_comp_chan;
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u8 cfg_slot;
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bool live;
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@ -203,6 +210,7 @@ struct ad7173_channel {
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unsigned int ain;
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struct ad7173_channel_config cfg;
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u8 syscalib_mode;
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bool openwire_det_en;
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};
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struct ad7173_state {
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@ -394,6 +402,76 @@ static int ad7173_calibrate_all(struct ad7173_state *st, struct iio_dev *indio_d
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return 0;
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}
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/*
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* Associative array of channel pairs for open wire detection
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* The array is indexed by ain and gives the associated channel pair
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* to perform the open wire detection with
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* the channel pair [0] is for non differential and pair [1]
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* is for differential inputs
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*/
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static int openwire_ain_to_channel_pair[][2][2] = {
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/* AIN Single Differential */
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[0] = { { 0, 15 }, { 1, 2 } },
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[1] = { { 1, 2 }, { 2, 1 } },
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[2] = { { 3, 4 }, { 5, 6 } },
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[3] = { { 5, 6 }, { 6, 5 } },
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[4] = { { 7, 8 }, { 9, 10 } },
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[5] = { { 9, 10 }, { 10, 9 } },
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[6] = { { 11, 12 }, { 13, 14 } },
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[7] = { { 13, 14 }, { 14, 13 } },
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};
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/*
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* Openwire detection on ad4111 works by running the same input measurement
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* on two different channels and compare if the difference between the two
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* measurements exceeds a certain value (typical 300mV)
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*/
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static int ad4111_openwire_event(struct iio_dev *indio_dev,
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const struct iio_chan_spec *chan)
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{
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struct ad7173_state *st = iio_priv(indio_dev);
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struct ad7173_channel *adchan = &st->channels[chan->address];
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struct ad7173_channel_config *cfg = &adchan->cfg;
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int ret, val1, val2;
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ret = regmap_set_bits(st->reg_gpiocon_regmap, AD7173_REG_GPIO,
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AD4111_GPIO_GP_OW_EN);
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if (ret)
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return ret;
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adchan->cfg.openwire_comp_chan =
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openwire_ain_to_channel_pair[chan->channel][chan->differential][0];
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ret = ad_sigma_delta_single_conversion(indio_dev, chan, &val1);
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if (ret < 0) {
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dev_err(&indio_dev->dev,
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"Error running ad_sigma_delta single conversion: %d", ret);
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goto out;
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}
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adchan->cfg.openwire_comp_chan =
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openwire_ain_to_channel_pair[chan->channel][chan->differential][1];
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ret = ad_sigma_delta_single_conversion(indio_dev, chan, &val2);
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if (ret < 0) {
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dev_err(&indio_dev->dev,
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"Error running ad_sigma_delta single conversion: %d", ret);
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goto out;
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}
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if (abs(val1 - val2) > cfg->openwire_thrsh_raw)
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iio_push_event(indio_dev,
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IIO_UNMOD_EVENT_CODE(IIO_VOLTAGE, chan->address,
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IIO_EV_TYPE_FAULT, IIO_EV_DIR_FAULT_OPENWIRE),
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iio_get_time_ns(indio_dev));
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out:
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adchan->cfg.openwire_comp_chan = -1;
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regmap_clear_bits(st->reg_gpiocon_regmap, AD7173_REG_GPIO,
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AD4111_GPIO_GP_OW_EN);
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return ret;
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}
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static int ad7173_mask_xlate(struct gpio_regmap *gpio, unsigned int base,
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unsigned int offset, unsigned int *reg,
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unsigned int *mask)
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@ -591,6 +669,9 @@ static int ad7173_set_channel(struct ad_sigma_delta *sd, unsigned int channel)
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FIELD_PREP(AD7173_CH_SETUP_SEL_MASK, st->channels[channel].cfg.cfg_slot) |
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st->channels[channel].ain;
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if (st->channels[channel].cfg.openwire_comp_chan >= 0)
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channel = st->channels[channel].cfg.openwire_comp_chan;
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return ad_sd_write_reg(&st->sd, AD7173_REG_CH(channel), 2, val);
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}
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@ -639,6 +720,11 @@ static int ad7173_disable_all(struct ad_sigma_delta *sd)
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static int ad7173_disable_one(struct ad_sigma_delta *sd, unsigned int chan)
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{
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struct ad7173_state *st = ad_sigma_delta_to_ad7173(sd);
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if (st->channels[chan].cfg.openwire_comp_chan >= 0)
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chan = st->channels[chan].cfg.openwire_comp_chan;
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return ad_sd_write_reg(sd, AD7173_REG_CH(chan), 2, 0);
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}
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@ -690,6 +776,7 @@ static const struct ad7173_device_info ad4111_device_info = {
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.has_current_inputs = true,
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.has_int_ref = true,
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.has_internal_fs_calibration = true,
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.has_openwire_det = true,
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.clock = 2 * HZ_PER_MHZ,
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.sinc5_data_rates = ad7173_sinc5_data_rates,
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.num_sinc5_data_rates = ARRAY_SIZE(ad7173_sinc5_data_rates),
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@ -1000,6 +1087,12 @@ static int ad7173_read_raw(struct iio_dev *indio_dev,
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if (ret < 0)
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return ret;
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if (ch->openwire_det_en) {
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ret = ad4111_openwire_event(indio_dev, chan);
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if (ret < 0)
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return ret;
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}
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return IIO_VAL_INT;
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case IIO_CHAN_INFO_SCALE:
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@ -1144,12 +1237,57 @@ static int ad7173_debug_reg_access(struct iio_dev *indio_dev, unsigned int reg,
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return ad_sd_write_reg(&st->sd, reg, reg_size, writeval);
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}
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static int ad7173_write_event_config(struct iio_dev *indio_dev,
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const struct iio_chan_spec *chan,
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enum iio_event_type type,
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enum iio_event_direction dir,
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bool state)
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{
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struct ad7173_state *st = iio_priv(indio_dev);
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struct ad7173_channel *adchan = &st->channels[chan->address];
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switch (type) {
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case IIO_EV_TYPE_FAULT:
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adchan->openwire_det_en = state;
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return 0;
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default:
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return -EINVAL;
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}
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}
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static int ad7173_read_event_config(struct iio_dev *indio_dev,
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const struct iio_chan_spec *chan,
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enum iio_event_type type,
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enum iio_event_direction dir)
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{
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struct ad7173_state *st = iio_priv(indio_dev);
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struct ad7173_channel *adchan = &st->channels[chan->address];
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switch (type) {
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case IIO_EV_TYPE_FAULT:
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return adchan->openwire_det_en;
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default:
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return -EINVAL;
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}
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}
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static const struct iio_event_spec ad4111_events[] = {
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{
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.type = IIO_EV_TYPE_FAULT,
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.dir = IIO_EV_DIR_FAULT_OPENWIRE,
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.mask_separate = BIT(IIO_EV_INFO_VALUE),
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.mask_shared_by_all = BIT(IIO_EV_INFO_ENABLE),
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},
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};
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static const struct iio_info ad7173_info = {
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.read_raw = &ad7173_read_raw,
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.write_raw = &ad7173_write_raw,
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.debugfs_reg_access = &ad7173_debug_reg_access,
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.validate_trigger = ad_sd_validate_trigger,
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.update_scan_mode = ad7173_update_scan_mode,
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.write_event_config = ad7173_write_event_config,
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.read_event_config = ad7173_read_event_config,
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};
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static const struct iio_scan_type ad4113_scan_type = {
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@ -1353,6 +1491,37 @@ static int ad7173_validate_reference(struct ad7173_state *st, int ref_sel)
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return 0;
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}
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static int ad7173_validate_openwire_ain_inputs(struct ad7173_state *st,
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bool differential,
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unsigned int ain0,
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unsigned int ain1)
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{
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/*
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* If the channel is configured as differential,
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* the ad4111 requires specific ains to be used together
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*/
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if (differential)
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return (ain0 % 2) ? (ain0 - 1) == ain1 : (ain0 + 1) == ain1;
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return ain1 == AD4111_VINCOM_INPUT;
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}
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static unsigned int ad7173_calc_openwire_thrsh_raw(struct ad7173_state *st,
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struct iio_chan_spec *chan,
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struct ad7173_channel *chan_st_priv,
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unsigned int thrsh_mv) {
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unsigned int thrsh_raw;
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thrsh_raw =
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BIT(chan->scan_type.realbits - !!(chan_st_priv->cfg.bipolar))
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* thrsh_mv
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/ ad7173_get_ref_voltage_milli(st, chan_st_priv->cfg.ref_sel);
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if (chan->channel < st->info->num_voltage_in_div)
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thrsh_raw /= AD4111_DIVIDER_RATIO;
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return thrsh_raw;
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}
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static int ad7173_fw_parse_channel_config(struct iio_dev *indio_dev)
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{
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struct ad7173_channel *chans_st_arr, *chan_st_priv;
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@ -1400,6 +1569,7 @@ static int ad7173_fw_parse_channel_config(struct iio_dev *indio_dev)
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chan_st_priv->cfg.bipolar = false;
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chan_st_priv->cfg.input_buf = st->info->has_input_buf;
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chan_st_priv->cfg.ref_sel = AD7173_SETUP_REF_SEL_INT_REF;
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chan_st_priv->cfg.openwire_comp_chan = -1;
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st->adc_mode |= AD7173_ADC_MODE_REF_EN;
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if (st->info->data_reg_only_16bit)
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chan_arr[chan_index].scan_type = ad4113_scan_type;
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@ -1466,6 +1636,7 @@ static int ad7173_fw_parse_channel_config(struct iio_dev *indio_dev)
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chan->channel = ain[0];
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chan_st_priv->cfg.input_buf = st->info->has_input_buf;
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chan_st_priv->cfg.odr = 0;
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chan_st_priv->cfg.openwire_comp_chan = -1;
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chan_st_priv->cfg.bipolar = fwnode_property_read_bool(child, "bipolar");
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if (chan_st_priv->cfg.bipolar)
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@ -1480,6 +1651,14 @@ static int ad7173_fw_parse_channel_config(struct iio_dev *indio_dev)
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chan_st_priv->cfg.input_buf = st->info->has_input_buf;
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chan->channel2 = ain[1];
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chan_st_priv->ain = AD7173_CH_ADDRESS(ain[0], ain[1]);
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if (st->info->has_openwire_det &&
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ad7173_validate_openwire_ain_inputs(st, chan->differential, ain[0], ain[1])) {
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chan->event_spec = ad4111_events;
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chan->num_event_specs = ARRAY_SIZE(ad4111_events);
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chan_st_priv->cfg.openwire_thrsh_raw =
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ad7173_calc_openwire_thrsh_raw(st, chan, chan_st_priv,
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AD4111_OW_DET_THRSH_MV);
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}
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}
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if (st->info->data_reg_only_16bit)
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