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433 lines
10 KiB
433 lines
10 KiB
// SPDX-License-Identifier: GPL-2.0+ |
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/* |
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* lmp91000.c - Support for Texas Instruments digital potentiostats |
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* |
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* Copyright (C) 2016, 2018 |
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* Author: Matt Ranostay <[email protected]> |
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* |
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* TODO: bias voltage + polarity control, and multiple chip support |
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*/ |
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#include <linux/module.h> |
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#include <linux/i2c.h> |
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#include <linux/delay.h> |
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#include <linux/mod_devicetable.h> |
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#include <linux/regmap.h> |
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#include <linux/iio/iio.h> |
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#include <linux/iio/buffer.h> |
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#include <linux/iio/consumer.h> |
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#include <linux/iio/trigger.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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#define LMP91000_REG_LOCK 0x01 |
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#define LMP91000_REG_TIACN 0x10 |
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#define LMP91000_REG_TIACN_GAIN_SHIFT 2 |
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#define LMP91000_REG_REFCN 0x11 |
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#define LMP91000_REG_REFCN_EXT_REF 0x20 |
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#define LMP91000_REG_REFCN_50_ZERO 0x80 |
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#define LMP91000_REG_MODECN 0x12 |
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#define LMP91000_REG_MODECN_3LEAD 0x03 |
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#define LMP91000_REG_MODECN_TEMP 0x07 |
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#define LMP91000_DRV_NAME "lmp91000" |
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static const int lmp91000_tia_gain[] = { 0, 2750, 3500, 7000, 14000, 35000, |
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120000, 350000 }; |
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static const int lmp91000_rload[] = { 10, 33, 50, 100 }; |
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#define LMP91000_TEMP_BASE -40 |
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static const u16 lmp91000_temp_lut[] = { |
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1875, 1867, 1860, 1852, 1844, 1836, 1828, 1821, 1813, 1805, |
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1797, 1789, 1782, 1774, 1766, 1758, 1750, 1742, 1734, 1727, |
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1719, 1711, 1703, 1695, 1687, 1679, 1671, 1663, 1656, 1648, |
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1640, 1632, 1624, 1616, 1608, 1600, 1592, 1584, 1576, 1568, |
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1560, 1552, 1544, 1536, 1528, 1520, 1512, 1504, 1496, 1488, |
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1480, 1472, 1464, 1456, 1448, 1440, 1432, 1424, 1415, 1407, |
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1399, 1391, 1383, 1375, 1367, 1359, 1351, 1342, 1334, 1326, |
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1318, 1310, 1302, 1293, 1285, 1277, 1269, 1261, 1253, 1244, |
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1236, 1228, 1220, 1212, 1203, 1195, 1187, 1179, 1170, 1162, |
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1154, 1146, 1137, 1129, 1121, 1112, 1104, 1096, 1087, 1079, |
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1071, 1063, 1054, 1046, 1038, 1029, 1021, 1012, 1004, 996, |
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987, 979, 971, 962, 954, 945, 937, 929, 920, 912, |
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903, 895, 886, 878, 870, 861 }; |
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static const struct regmap_config lmp91000_regmap_config = { |
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.reg_bits = 8, |
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.val_bits = 8, |
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}; |
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struct lmp91000_data { |
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struct regmap *regmap; |
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struct device *dev; |
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struct iio_trigger *trig; |
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struct iio_cb_buffer *cb_buffer; |
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struct iio_channel *adc_chan; |
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struct completion completion; |
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u8 chan_select; |
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u32 buffer[4]; /* 64-bit data + 64-bit timestamp */ |
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}; |
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static const struct iio_chan_spec lmp91000_channels[] = { |
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{ /* chemical channel mV */ |
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.type = IIO_VOLTAGE, |
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.channel = 0, |
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.address = LMP91000_REG_MODECN_3LEAD, |
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.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | |
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BIT(IIO_CHAN_INFO_OFFSET) | |
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BIT(IIO_CHAN_INFO_SCALE), |
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.scan_index = 0, |
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.scan_type = { |
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.sign = 's', |
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.realbits = 32, |
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.storagebits = 32, |
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}, |
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}, |
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IIO_CHAN_SOFT_TIMESTAMP(1), |
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{ /* temperature channel mV */ |
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.type = IIO_TEMP, |
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.channel = 1, |
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.address = LMP91000_REG_MODECN_TEMP, |
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.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED), |
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.scan_index = -1, |
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}, |
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}; |
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static int lmp91000_read(struct lmp91000_data *data, int channel, int *val) |
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{ |
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int state, ret; |
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ret = regmap_read(data->regmap, LMP91000_REG_MODECN, &state); |
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if (ret) |
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return -EINVAL; |
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ret = regmap_write(data->regmap, LMP91000_REG_MODECN, channel); |
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if (ret) |
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return -EINVAL; |
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/* delay till first temperature reading is complete */ |
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if (state != channel && channel == LMP91000_REG_MODECN_TEMP) |
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usleep_range(3000, 4000); |
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data->chan_select = channel != LMP91000_REG_MODECN_3LEAD; |
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iio_trigger_poll_chained(data->trig); |
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ret = wait_for_completion_timeout(&data->completion, HZ); |
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reinit_completion(&data->completion); |
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if (!ret) |
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return -ETIMEDOUT; |
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*val = data->buffer[data->chan_select]; |
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return 0; |
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} |
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static irqreturn_t lmp91000_buffer_handler(int irq, void *private) |
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{ |
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struct iio_poll_func *pf = private; |
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struct iio_dev *indio_dev = pf->indio_dev; |
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struct lmp91000_data *data = iio_priv(indio_dev); |
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int ret, val; |
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memset(data->buffer, 0, sizeof(data->buffer)); |
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ret = lmp91000_read(data, LMP91000_REG_MODECN_3LEAD, &val); |
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if (!ret) { |
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data->buffer[0] = val; |
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iio_push_to_buffers_with_timestamp(indio_dev, data->buffer, |
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iio_get_time_ns(indio_dev)); |
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} |
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iio_trigger_notify_done(indio_dev->trig); |
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return IRQ_HANDLED; |
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} |
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static int lmp91000_read_raw(struct iio_dev *indio_dev, |
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struct iio_chan_spec const *chan, |
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int *val, int *val2, long mask) |
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{ |
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struct lmp91000_data *data = iio_priv(indio_dev); |
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switch (mask) { |
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case IIO_CHAN_INFO_RAW: |
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case IIO_CHAN_INFO_PROCESSED: { |
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int ret = iio_channel_start_all_cb(data->cb_buffer); |
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if (ret) |
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return ret; |
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ret = lmp91000_read(data, chan->address, val); |
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iio_channel_stop_all_cb(data->cb_buffer); |
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if (ret) |
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return ret; |
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if (mask == IIO_CHAN_INFO_PROCESSED) { |
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int tmp, i; |
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ret = iio_convert_raw_to_processed(data->adc_chan, |
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*val, &tmp, 1); |
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if (ret) |
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return ret; |
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for (i = 0; i < ARRAY_SIZE(lmp91000_temp_lut); i++) |
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if (lmp91000_temp_lut[i] < tmp) |
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break; |
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*val = (LMP91000_TEMP_BASE + i) * 1000; |
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} |
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return IIO_VAL_INT; |
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} |
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case IIO_CHAN_INFO_OFFSET: |
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return iio_read_channel_offset(data->adc_chan, val, val2); |
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case IIO_CHAN_INFO_SCALE: |
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return iio_read_channel_scale(data->adc_chan, val, val2); |
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} |
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return -EINVAL; |
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} |
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static const struct iio_info lmp91000_info = { |
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.read_raw = lmp91000_read_raw, |
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}; |
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static int lmp91000_read_config(struct lmp91000_data *data) |
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{ |
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struct device *dev = data->dev; |
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unsigned int reg, val; |
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int i, ret; |
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ret = device_property_read_u32(dev, "ti,tia-gain-ohm", &val); |
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if (ret) { |
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if (!device_property_read_bool(dev, "ti,external-tia-resistor")) { |
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dev_err(dev, "no ti,tia-gain-ohm defined and external resistor not specified\n"); |
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return ret; |
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} |
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val = 0; |
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} |
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ret = -EINVAL; |
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for (i = 0; i < ARRAY_SIZE(lmp91000_tia_gain); i++) { |
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if (lmp91000_tia_gain[i] == val) { |
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reg = i << LMP91000_REG_TIACN_GAIN_SHIFT; |
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ret = 0; |
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break; |
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} |
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} |
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if (ret) { |
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dev_err(dev, "invalid ti,tia-gain-ohm %d\n", val); |
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return ret; |
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} |
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ret = device_property_read_u32(dev, "ti,rload-ohm", &val); |
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if (ret) { |
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val = 100; |
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dev_info(dev, "no ti,rload-ohm defined, default to %d\n", val); |
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} |
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ret = -EINVAL; |
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for (i = 0; i < ARRAY_SIZE(lmp91000_rload); i++) { |
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if (lmp91000_rload[i] == val) { |
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reg |= i; |
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ret = 0; |
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break; |
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} |
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} |
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if (ret) { |
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dev_err(dev, "invalid ti,rload-ohm %d\n", val); |
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return ret; |
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} |
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regmap_write(data->regmap, LMP91000_REG_LOCK, 0); |
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regmap_write(data->regmap, LMP91000_REG_TIACN, reg); |
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regmap_write(data->regmap, LMP91000_REG_REFCN, |
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LMP91000_REG_REFCN_EXT_REF | LMP91000_REG_REFCN_50_ZERO); |
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regmap_write(data->regmap, LMP91000_REG_LOCK, 1); |
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return 0; |
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} |
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static int lmp91000_buffer_cb(const void *val, void *private) |
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{ |
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struct iio_dev *indio_dev = private; |
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struct lmp91000_data *data = iio_priv(indio_dev); |
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data->buffer[data->chan_select] = *((int *)val); |
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complete_all(&data->completion); |
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return 0; |
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} |
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static const struct iio_trigger_ops lmp91000_trigger_ops = { |
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}; |
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static int lmp91000_buffer_postenable(struct iio_dev *indio_dev) |
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{ |
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struct lmp91000_data *data = iio_priv(indio_dev); |
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return iio_channel_start_all_cb(data->cb_buffer); |
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} |
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static int lmp91000_buffer_predisable(struct iio_dev *indio_dev) |
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{ |
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struct lmp91000_data *data = iio_priv(indio_dev); |
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iio_channel_stop_all_cb(data->cb_buffer); |
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return 0; |
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} |
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static const struct iio_buffer_setup_ops lmp91000_buffer_setup_ops = { |
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.postenable = lmp91000_buffer_postenable, |
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.predisable = lmp91000_buffer_predisable, |
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}; |
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static int lmp91000_probe(struct i2c_client *client, |
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const struct i2c_device_id *id) |
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{ |
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struct device *dev = &client->dev; |
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struct lmp91000_data *data; |
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struct iio_dev *indio_dev; |
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int ret; |
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indio_dev = devm_iio_device_alloc(dev, sizeof(*data)); |
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if (!indio_dev) |
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return -ENOMEM; |
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indio_dev->info = &lmp91000_info; |
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indio_dev->channels = lmp91000_channels; |
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indio_dev->num_channels = ARRAY_SIZE(lmp91000_channels); |
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indio_dev->name = LMP91000_DRV_NAME; |
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indio_dev->modes = INDIO_DIRECT_MODE; |
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i2c_set_clientdata(client, indio_dev); |
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data = iio_priv(indio_dev); |
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data->dev = dev; |
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data->regmap = devm_regmap_init_i2c(client, &lmp91000_regmap_config); |
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if (IS_ERR(data->regmap)) { |
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dev_err(dev, "regmap initialization failed.\n"); |
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return PTR_ERR(data->regmap); |
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} |
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data->trig = devm_iio_trigger_alloc(dev, "%s-mux%d", |
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indio_dev->name, indio_dev->id); |
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if (!data->trig) { |
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dev_err(dev, "cannot allocate iio trigger.\n"); |
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return -ENOMEM; |
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} |
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data->trig->ops = &lmp91000_trigger_ops; |
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init_completion(&data->completion); |
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ret = lmp91000_read_config(data); |
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if (ret) |
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return ret; |
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ret = iio_trigger_set_immutable(iio_channel_cb_get_iio_dev(data->cb_buffer), |
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data->trig); |
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if (ret) { |
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dev_err(dev, "cannot set immutable trigger.\n"); |
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return ret; |
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} |
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ret = iio_trigger_register(data->trig); |
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if (ret) { |
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dev_err(dev, "cannot register iio trigger.\n"); |
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return ret; |
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} |
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ret = iio_triggered_buffer_setup(indio_dev, NULL, |
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&lmp91000_buffer_handler, |
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&lmp91000_buffer_setup_ops); |
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if (ret) |
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goto error_unreg_trigger; |
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data->cb_buffer = iio_channel_get_all_cb(dev, &lmp91000_buffer_cb, |
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indio_dev); |
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if (IS_ERR(data->cb_buffer)) { |
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if (PTR_ERR(data->cb_buffer) == -ENODEV) |
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ret = -EPROBE_DEFER; |
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else |
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ret = PTR_ERR(data->cb_buffer); |
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goto error_unreg_buffer; |
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} |
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data->adc_chan = iio_channel_cb_get_channels(data->cb_buffer); |
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ret = iio_device_register(indio_dev); |
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if (ret) |
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goto error_unreg_cb_buffer; |
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return 0; |
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error_unreg_cb_buffer: |
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iio_channel_release_all_cb(data->cb_buffer); |
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error_unreg_buffer: |
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iio_triggered_buffer_cleanup(indio_dev); |
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error_unreg_trigger: |
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iio_trigger_unregister(data->trig); |
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return ret; |
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} |
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static int lmp91000_remove(struct i2c_client *client) |
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{ |
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struct iio_dev *indio_dev = i2c_get_clientdata(client); |
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struct lmp91000_data *data = iio_priv(indio_dev); |
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iio_device_unregister(indio_dev); |
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iio_channel_stop_all_cb(data->cb_buffer); |
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iio_channel_release_all_cb(data->cb_buffer); |
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iio_triggered_buffer_cleanup(indio_dev); |
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iio_trigger_unregister(data->trig); |
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return 0; |
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} |
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static const struct of_device_id lmp91000_of_match[] = { |
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{ .compatible = "ti,lmp91000", }, |
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{ .compatible = "ti,lmp91002", }, |
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{ }, |
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}; |
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MODULE_DEVICE_TABLE(of, lmp91000_of_match); |
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static const struct i2c_device_id lmp91000_id[] = { |
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{ "lmp91000", 0 }, |
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{ "lmp91002", 0 }, |
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{} |
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}; |
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MODULE_DEVICE_TABLE(i2c, lmp91000_id); |
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static struct i2c_driver lmp91000_driver = { |
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.driver = { |
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.name = LMP91000_DRV_NAME, |
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.of_match_table = lmp91000_of_match, |
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}, |
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.probe = lmp91000_probe, |
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.remove = lmp91000_remove, |
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.id_table = lmp91000_id, |
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}; |
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module_i2c_driver(lmp91000_driver); |
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MODULE_AUTHOR("Matt Ranostay <[email protected]>"); |
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MODULE_DESCRIPTION("LMP91000 digital potentiostat"); |
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MODULE_LICENSE("GPL");
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